How do I bi-amp componets?

Heh guys:

So I've noticed audiophiles always talk about bi-amping componets...  This means discretly running each componet from a seperate channel of the amp w/o a crossover?

What are some of the advantages of doing it this way instead of through a crossover?  Right now i'm running a JL Audio e6450... a 6 channel amp (45x6, 90x6, 150x3) and I have the front 4-channels bridged to a pair of CDT Audio componets...  150-watts to each side.  How would I go about discretely amping each componet? Typically, what is used to filter output? How would I go about bi-amping a pair of midbasses and a pair of tweeters from this amp?  Would it even be desirable?

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"I'm finished!" - Daniel Plainview

OK... You asked for it. LOL This is a whole can o' worms... There are people like myself who like bi-amping and people like DYohn who like passives. Neither is right or wrong. It is a taste issue.

TRUE bi-amping will require additional active crossovers to do it correctly. Firstly, you need to know where the crossover is set from your manufacturer, both frequency and slope. I would use this as a starting point when looking for a crossover point. It will by NO means be the end-all, be-all for you final resting point, and you will really want to have a good RTA and mic setup - that or an ear that REALLY KNOWS what the setup should sound like.

Some of the advantages:
1-Headroom
2-No frequency drift - ever
3-Damping improves
4-Flexibility
There are more, but these are the primary ones.

Some of the disadvantages:
1-Can be difficult to implement CORRECTLY
2-Expense of additional amp channels
3-Expense of additional crossovers
4-Expense of additional wire
Again, there are more, but you get the jist of it...

I can go on further, and if you would like, ask with specific questions. It is too extensive a subject matter to try to answer everything in broad strokes.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Note that you can reduce the required amplifier power by ~%15~20% when switching from a passive to active crossover system. Passive crossovers take up quite a bit of power.

Also, you can COMPLETELY control ALL parameters of EACH driver using an active setup. Now, you can do this with passive crossovers, but it requires MUCH more work.

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Ah hamfist....  asking *moi* for specific questions?

1-Headroom - Here you refer to absolute SPL?
2-No frequency drift - What is frequency drift?
3-Damping improves - Damping?  Signal/Noise?  huh?

"additional active crossovers" - okay, my understanding of an 'active' crossover is one, in the signal path, that provides output.. say, the xover on the amp or the xover on the HU.  a 'passive' crossover is one that sits in the signal path and just cuts off something.. an external crossover or a bass-blocker or whatever. 

So in this case "additional active crossovers" is a signal processor?  My interest in this goes exactly as far as I need to move the crossovers in my car due to a horrible installation accident that I really don't wanna discuss here.... I'd really rather ditch them completely..  and I have this 6-channel amp..  soo. 

Yea my most specific question goes like this:  I wanna try bi-amping a set of JL Audio VR series midbasses with a set of CDT Audio 1" silk dome tweeters from the first 4 channels of a JL Audio e6450 b/c I think it would be really fun to do it.    So tell me everything you possibly can about that.

https://www.jlaudio.com/amps/e6450.html

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"I'm finished!" - Daniel Plainview

sedate wrote:

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Ah hamfist.... asking *moi* for specific questions?

1-Headroom - Here you refer to absolute SPL?
2-No frequency drift - What is frequency drift?
3-Damping improves - Damping? Signal/Noise? huh?

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Headroom is the difference in power required between the quietest passages and the loudest passages. The more headroom you have, the better your amplifier can handle the transients necessary to make your music more "lifelike". Without one 300WPC amplifier having to do a (relatively) HUGE portion of the spectrum, say 80 to 20K, you could use two somewhat smaller amps and split that wide range into smaller bands, for example 120 watts dedicated to 80 to 3500, and 45 watts dedicated to 3500 to 20K. Also, passive crossovers tend to smear transient response. i.e. "round-off" the sharp peaks required. You know, the stuff required to make a snare drum sound like a snare drum. Without requiring VERY high quality passive components in the crossover, you can use an active crossover instead. The op-amps in pretty much ANY active device will be faster than even the best quality passive components. I almost forgot... Yes absolute (peak, or transient) SPL is what headroom will affect directly. Average SPL *MIGHT* be better as well, but overall, the average is really determined by the capacity of your drivers. Frequency drift is what happens when your caps and coils change values (although it is a SLIGHT change) due to age and/or temperature. Damping is the back EMF from the voice coils being shorted against itself inside the amplifiers output devices. It improves because there is significantly less wire between the voice coil and the output terminals of the amplifier. Signal to noise is simply the sssssssssss you hear in the background between songs, or in quiet passages. The higher the S/N ratio, the less sssssssssss you hear.

sedate wrote:

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"additional active crossovers" - okay, my understanding of an 'active' crossover is one, in the signal path, that provides output.. say, the xover on the amp or the xover on the HU. a 'passive' crossover is one that sits in the signal path and just cuts off something.. an external crossover or a bass-blocker or whatever.

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They really both do the same thing, just in different physical places in the signal chain. Active is placed between the source (your HU or EQ) and the destination (the amp). It is actually considered a gain stage, and this is why it is so important to choose VERY carefully your active devices. A passive crossover, can be as simple as a capacitor in a tweeter lead, or a coil (inductor) in a woofer lead. A single device such as a cap or coil, will provide a 6dB slope, and you add more caps or coils in any combination of series and/or parallel, to increase the slope (or the order - each order adds 6dB. 1st-6dB, 2nd-12dB, 3rd-18dB and so on). When you get to higher order crossovers, especially low pass crossovers, the amount of wire in the inductors can be significant, thus reducing the amount of power available for your speaker system. The additional resistance also reduces the damping factor of the system.

sedate wrote:

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So in this case "additional active crossovers" is a signal processor? My interest in this goes exactly as far as I need to move the crossovers in my car due to a horrible installation accident that I really don't wanna discuss here.... I'd really rather ditch them completely.. and I have this 6-channel amp.. soo.

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The amp, I see, can be run as a 4 channel? Is this correct? 2X45 and 2X150? PERFECT! I have no idea how flexible the crossovers are inside the amp, but if you can set it to HP at 3500 or so (for the tweeters @ 45wpc), and LP at 3500 or so (for the mid-bass @ 150wpc), you'd be set. IF not, you need an external crossover - something like the Audio Control 6XS (adjusted by chips or resistors, and semi-fixed) or the Altomobile UCSPro (digital and INFINITELY flexible and adjustable). This will put you into a bit of an overpowered situation, so you would of course, need to be exceptionally careful in your use of the volume control...

sedate wrote:

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Yea my most specific question goes like this: I wanna try bi-amping a set of JL Audio VR series midbasses with a set of CDT Audio 1" silk dome tweeters from the first 4 channels of a JL Audio e6450 b/c I think it would be really fun to do it. So tell me everything you possibly can about that.

https://www.jlaudio.com/amps/e6450.html

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This amp won't do it in native mode. You'll simply HAVE to buy another croosver - an outboard one will be necessary.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I want to add what I believe are the largest positives and negatives to this endeavor.

Positive:  If pulled off, an incredible sounding system that is much better than the passive crossovers.  They will now be tuned to your vehicle and your personal tastes.

Negative:  It is extremely difficult to pull off without expensive test equipment, a good ear, and some pretty extensive knowledge.

Sedate; from what I've seen of you I believe you could pull it iff.  You seem to be very bright, and have the drive to pursue this to it's end.  Plus with people like Haemphyst helping you, I think the odds are greatly in your favor.  I will try to help you if I can as well.

What I recommend is that you pick up a good processor with a parametric EQ and crossover.  You will want something that will offer quite a bit of flexibility so you don't have to "settle".

Steven Kephart

Adire Audio

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First, Thanks for the vote, Steven!

Second, I have to echo Steven's input there, regarding the flexibility aspect... It will be helpful to have it! My personal recommendation would be the UCSPro from Alto. It is an EXPENSIVE piece, I think around $600 or so (maybe more... I don't know), but the digital aspect of it is an amazing help for systems just such as yours. It will provide you with Crossover Capabilities up to 48dB, Noise Gates, 31 bands of TRUE Parametric Equalization, Time Delay (alignment), and Dynamic Compression and Limiting. A true set it and forget it piece of equipment. I have TWO (2) of them! One for the highs, and one dedicated to my subwoofer. It's ONLY drawback, (but a blessing as well - 'cause people cant futz with your settings once you set it all up) is that it REQUIRES a PC to set it...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

"sedate; from what I've seen of you I believe you could pull it iff.  You seem to be very bright, and have the drive to pursue this to it's end."

<---  pulls at collar sheepishly>  Yea really Steven thanks for the vote!

"It is extremely difficult to pull off without expensive test equipment, a good ear, and some pretty extensive knowledge."

Now this may be naive brash talking, but (and just maybe u and hamfist can relate), after reading what u and hamfist say... it sounds like this is the way to get my front end sounding the way *I* want.  I'm always screwing off with the top end cuz *every* comp set I buy sounds screechy to me outta the box.  I dunno why.  Once I eq-out that high-end, then I get into the nitty-gritty like midbass-response, detail... etc., etc.

Once again I find myself cursing my decision to pick up the cheapo, high-current JL stuff instead of the orgasmic "Slash" series... =/    
Yea no kidding hamfist that signal processor is a beast.. but .. uhh... dude... I wait tables.  (I kid you not I say things like "That comes with a side salad or side pasta, what would you like tonight?") My girlfriend just kicked me out, and I just paid tution and books for the summer semester, and hence I now owe Capital One *even more* money.  That thing simply can't happen right now.   Sometimes I work 3 weeks for that kinda cheese. 

Of course, never to be deterred, what would u guys look at in say.. the $100 - $300 range?  That I might be able to cough up here in the next few weeks.. (one thing I truly love about this country... no matter how sticky the freedom/security situation can ever get.. obtaining *stuff* will only ever require a signature and a smile... money isn't even real anymore... )  I get the impression to do this properly would require active crossing.. anything I add after the amp would be a static cross and from what Steven said to do this properly would *require* active adjustability... and I've been looking for an excuse to get an proper eq..  

So whatchu guys think?  I can't dump that kinda cash on a bonkers signal processor right now so I ought stick with passive xovers and wait for a brighter day?  Or can u guys recommend something a wee bit more not <more than my rent> and then we can take a stab at this?  What ever you recommend it will be installed in my trunk, so looks/c**kpit adjustablility is not the deciding factor here...  functionality and *price* is.  Of course, anything that would be movable to a nice 2xDIN opening in a new car that might complement.. say.. an Alpine CDA-9833 would of course be... welcome.

Cheers guys thanks for the help. 

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"I'm finished!" - Daniel Plainview

I might have something for you...

Just to let you know, I am not forgetting or ignoring you... I'll reply from work where I have a little more time!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

sedate, I found the item I was looking for, for you... It is an AudioControl EQX. On the bottom right of the page, there is a link to the owner's manual, and this is an older generation (GenII, I think, pretty much just a different paint job), but identical in specs to the new stuff. All of the crossovers work, and there are no noisy pots... It's an old school version, but it is in EXCELLENT shape, and I would be willing to let it go for a "starving actor type" such as yourself for a good price, probably within the first half of that range you stated above. Let me know if you are interested. I'll send you some pics if you'd like...

It's certainly not a "bonkers" unit, but a nice piece, nonetheless. I just don't need it anymore, because I have my UCS units, and they do PLENTY! It is a shame to see a nice piece like this just sitting in the garage, potentially rotting away...

Really, man, sorry to hear about your GF kicking you out... women... What would we do without them? OK, don't think about it!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

You there sedate?

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Yea.

Sorry.  Kinda had a long weekend.

I had to look at that thing for a minute to figure it out.  whew.

haemphyst wrote:

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sedate, I found the item I was looking for, for you... It is an AudioControl EQX. On the bottom right of the page, there is a link to the owner's manual, and this is an older generation (GenII, I think, pretty much just a different paint job), but identical in specs to the new stuff. All of the crossovers work, and there are no noisy pots... It's an old school version, but it is in EXCELLENT shape, and I would be willing to let it go for a "starving actor type" such as yourself for a good price, probably within the first half of that range you stated above. Let me know if you are interested. I'll send you some pics if you'd like...

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What is a noisy pot? 

"Starving actor type?"  Hehe alright I appreciate that.  But I have questions..!

haemphyst wrote:

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It's certainly not a "bonkers" unit, but a nice piece, nonetheless. I just don't need it anymore, because I have my UCS units, and they do PLENTY! It is a shame to see a nice piece like this just sitting in the garage, potentially rotting away...

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Yea I'll agree with not letting it rot..  Okay here is what it looks like to me though.. Follow along and tell me if this is all correct.. this is how my system plan is forming in my head:

Front RCA output --> Signal Processor --> First 2 sets of RCA inputs on JL 6450 -->First 4 channels to Tweeters/Midbass

Rear RCA output --> Rear RCA input on JL 6450 --> Rear Fill

Now here is the sticky wicket:  The EQX has a set crossover point..  at 90hz no less.. which for what we're discussing makes it fairly useless... except u can change it out it with a resistor?  Like they give a formula and say that u can swap it out for a different one and change the xover point as needed?  Have you changed urs?  My sense of this would say that being able to adjust the xover point for proper tuning would be *very* important... so hows that work? It looks pretty simple in the .pdf but how expensive/obtainable are resistors for this thing?  Or is this another one of those "radio shack" moments?  What about this "Programmable Frequency Module"-subsonic filter thing..  that works the same way? Just do the math to get the resistor value and plug it in?  Tell me all about that.

haemphyst wrote:

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Really, man, sorry to hear about your GF kicking you out... women... What would we do without them? OK, don't think about it!

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Yea.  Huh.  Its okay.  She hated my stereo anyway.

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"I'm finished!" - Daniel Plainview

Number one: No offense intended by the starving actor thing, K?

Number two: A "noisy pot" would be like a scratchy volume control... you know, when you go to turn up the volume on your stereo, and you get the scratch, then when you release the knob, most always it'll go back to clean sound... that's all I was sayin'...

Number three: Unless you REALLY want rear fill, I'd forget the rear fill, bridge the amp to 4 channels, and run all four to the front stage. I think you'll be plenty happy with the way it sounds. The PFM is really just a high-pass crossover point, in the one I have, it happens to be set for 30Hz. I don't have the math for figuring the resistor values for that plug-in, (it will be different than the XO module) but I should be able to get it fairly easily from Audio Control - that, or actually order the modules for the HP crossover point you want - I bet they can't be more than a few bucks each...

Number four: The EQX is (pretty much) completely adjustable. It's flexibility will ONLY be determined by the availability of 5% resistors in your area. Radio Shack has a few in store, but MANY more are available online, and through any decent electronics PARTS store. They wouldn't EVER cost more than about 50 cents each, (closer to the 10 cent area) and the 14 pin sockets (for the PFM) and the 16 pin sockets (for the XO Module)?? I've never seen them for more than two dollars each anywhere...

In fact here's a place you can get SOME values already assembled - you need type C. Also, here is a place to get the actual sockets, ready for you to put the actual resistors of choice in place... You need one 14 pin, (the PFM) and one 16 pin (the XO mod). My 16 pin, BTW has gone missing, so you WILL need one. If you let me know the crossover value right now in your passives, I will build a network for that XO point and have it plugged in for you, if you decide you want this thing...



I need to go - the wife has to take an online test for her work right now, but there's some info to chew on for a bit. Any more questions, just ask.

Number five: and if she really hated your stereo THAT much, you didn't need her anyway... (JK... only a jab, man)

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Yea I want it.

Naww I knew you didn't mean nothin, I wouldn't a whined about $$$ if I cared anyway.   I work like 30 hours a week serving tables... 'starving actor type' is pretty accurate.  I like 'starving student' more though... just cuz theatre-freaks kinda annoy me.

Huh I've never heard of a volume knob that does that.

Hmm... okay how does this resistor thing work?  I have to get the resistor and plug it into some other sort of componet (those 14 or 16 pin sockets on the second link?) which hooks onto the EQX?

Is this math just the formula in the .pdf?  7200/<desired xo point in hz> = resistor value in kohms?

So this is kinda easy.. just get the little socket, get the resistor, plug it in, and then plug the socket onto the EQX and change the XO point.....? same for the PFM but that I'd kinda set and forget?

So I've never bought something from someone over a forum like this.  How's sis supposed to work?  

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"I'm finished!" - Daniel Plainview

1: OK

2: Alrightie, then. Student it is... LOL (Sure hope I don't know any "theater-freaks". BWAHAHAH!!)

3: Old school volume knobs used to do it... today's digital stuff does not.

4: Actually, you'll solder the resistors (8 for the XO, and 7 for the PFM) to the header... smallish parts, but pretty easy to do. The compnents are not temerature sensitive... Here's a schematic of what they'll look like, electrically, anyway... (and pretty close, physically, too) The header will make it easy to change frequency points "at will" as it were... unplug one, plug in a different one. Done

This is just a quick diagram for the 16 pin version, the 14 pin is identical, save two leads and one resistor.

5: Yes, that's the math for the XO mod, but the math will be different for the PFM, but I'll call (e-mail, actually) tech support for AudioControl, and get that math for you... It'll be pretty simple as well.

6: Yep, that's it... easy peasy. 8 resistors in a convenient little carrier, plug it in, both the PFM and the XO mod, and forget it.

7: PM me, and I'll get you my PayPal info, and you can provide me with a shipping address... easiest that way for both of us. Does $150.00, including freight and insurance sound fair?

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Here's the pdf for figuring the values for the resistors... Seems the numbers are the same for both the PFM and the XO mods... Also, any of the standard values that are listed on the PDF are $10.00 plus S&H, as per the guys at AudioControl... To order any of the standard values, call them at 425-775-8461. Anything OTHER than a standard value, obviously you will need to build...

BTW, the PFM is and 18dB module, and the XO mod is a 24dB module...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

$150 shipped?  We sir, have a deal.

haemphyst wrote:

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Here's the pdf for figuring the values for the resistors... Seems the numbers are the same for both the PFM and the XO mods... Also, any of the standard values that are listed on the PDF are $10.00 plus S&H, as per the guys at AudioControl... To order any of the standard values, call them at 425-775-8461. Anything OTHER than a standard value, obviously you will need to build...

BTW, the PFM is and 18dB module, and the XO mod is a 24dB module...

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Could I build the XO modules myself or would ordering them from AudioControl be the easiest way to do this? My concern is that ordering something like that from a company would take 2 or 3 months...?

Okay well.. help me out a bit..  I'm thinking if I did that, for what we've discussed, the XO at 5000hz and the PFM at 120hz?  Ultimately, I'd like a set of these for my midbass.

https://www.thezeb.com/p-CDT-Audio-HD-5-5-1-4-inch-Midbass-Speakers-101068.htm

I was also looking at these, especially cuz of the 2-ohm rating.. but the XO point seems rather low for a midbass?

https://www.cardomain.com/item/IDSCX52

What do u think?  What would you be looking at?  I was going to try my old VR series midbasses.. they were *excellent* but I *did* kill one of them .. the CDT Classic series midbasses in my car now are...  well.   They need to go.

You mean 18dB module and 24dB module like... the "slope/octave"

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"I'm finished!" - Daniel Plainview

sedate wrote:

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$150 shipped? We sir, have a deal.

haemphyst wrote:

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Here's the pdf for figuring the values for the resistors... Seems the numbers are the same for both the PFM and the XO mods... Also, any of the standard values that are listed on the PDF are $10.00 plus S&H, as per the guys at AudioControl... To order any of the standard values, call them at 425-775-8461. Anything OTHER than a standard value, obviously you will need to build...

BTW, the PFM is and 18dB module, and the XO mod is a 24dB module...

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Check yer PM...

sedate wrote:

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Could I build the XO modules myself or would ordering them from AudioControl be the easiest way to do this? My concern is that ordering something like that from a company would take 2 or 3 months...?

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If you want to go with standard crossover values, they have them in stock, for quick shipping turn-around. Seeing now which values are actually available, you can probably get by with the off-the-shelf parts... pretty good selection, actually. I was impressed. Also, I expect that a company like AudioControl is pretty fast. The guy I spoke with today said they are in stock, so I would think the shipping would be pretty fast. If I had to guess, next day shipping, with 4 to 5 days to you...

sedate wrote:

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Okay well.. help me out a bit.. I'm thinking if I did that, for what we've discussed, the XO at 5000hz and the PFM at 120hz? Ultimately, I'd like a set of these for my midbass.

https://www.thezeb.com/p-CDT-Audio-HD-5-5-1-4-inch-Midbass-Speakers-101068.htm

I was also looking at these, especially cuz of the 2-ohm rating.. but the XO point seems rather low for a midbass?

https://www.cardomain.com/item/IDSCX52

What do u think? What would you be looking at? I was going to try my old VR series midbasses.. they were *excellent* but I *did* kill one of them .. the CDT Classic series midbasses in my car now are... well.   They need to go.

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Both of those numbers are a bit high... While a 5.25 will go that high, it's gonna BEAM like a sonofabitch! I'm thinking around 90 or 100Hz, and somewhere in the 3K to 4K range for the tweeters. Before you take that as gospel, check the capabilities of the tweeters. A XO point like that MIGHT compromise the power handling capabilities of them...

Personally, I like the CDT's better. Better sensitivity, better power handling, and 4 ohms - pretty much the perfect driver for you... Using these will allow you to safely bridge the amp to 4 channels... 2x45 and 2x150 is pretty much a PERFECT power setting for a 2 way system in the door... As I said earlier, this WILL be overpowering a bit, but if you set your gains correctly, nothing will go wrong. I've been overpowering for YEARS, and it can be done, by ear, if you are careful!

sedate wrote:

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You mean 18dB module and 24dB module like... the "slope/octave"

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Exactly...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Just out of curiosity, why are you planning on going with a 3 way using mid basses?  This seems to complicate things even more, and drives up cost.  There are some good 6's out there that will give you all the mid bass you need, and have good response up to about 3kHz.  And there are some good tweeters that will play down that low as well. 

This is my own personal opinion based on what I've learned; but I suggest in your search being leery of metal coned mids.  The reason for this is that metal cone's produce peaks in the response that are excited by motor linearities and therefore cannot be filtered out.  Granted poly cones do have dips in the response due to cone break-up, but dips are much less audible than peaks.  I don't know if you have read it yet or not, but my boss provided some good information that is relevant here in this link: https://forum.soundillusions.net/articles.php?action=viewarticle&artid=3

Steven Kephart

Adire Audio

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Steven Kephart:

I don't know if we're on the same page.. when I say "midbass" i mean 5.25 componet speaker.. if you are distinguishing between "midbass" and "midrange" .. I'm not.. I thought they were, in this particular application anyway, the same thing.

I'm not sure what you mean "going with a 3-way using midbasses." I can't use a 6.5" speaker b/c the 5.25's are already crammed in 4" holes! I don't mod the car itself... its one of my "Install Rules" (i.e., must have spare tire accessible, no cutting metal, etc.)

I already know to avoid metal coned tweeters... what materials would you recommend? I can't grab that article you posted "The Administrator(s) have not granted you sufficient permissions to view the Article Section."

What about the two speakers I posted above? You have any thoughts on those?

Hamfist:

BEAM like a sonofabitch? What do you mean by that?

I do know that technically the 2x45, 2x150 configuration will sound the best, but I really don't care for vehicles w/o rear-fill. It is *very* important to me. Sound is just so much more.. enveloping when rears are used.
I will be running each speaker discretely, at least to start.. 6x45 all around... which is why the 2-ohm mid from ID appealed to me... I do remember the jump from 45 watts to 150 watts when I still had my VR series componets in.. the difference was *massive* ... as remarkable as going from a single 12w0 to two Infinity Kappa Perfect 12's.



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"I'm finished!" - Daniel Plainview

sedate wrote:

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Steven Kephart:

I don't know if we're on the same page.. when I say "midbass" i mean 5.25 componet speaker.. if you are distinguishing between "midbass" and "midrange" .. I'm not.. I thought they were, in this particular application anyway, the same thing.

I'm not sure what you mean "going with a 3-way using midbasses." I can't use a 6.5" speaker b/c the 5.25's are already crammed in 4" holes! I don't mod the car itself... its one of my "Install Rules" (i.e., must have spare tire accessible, no cutting metal, etc.) 

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Ah, I totally misunderstood you then.  I'm sorry about that.  When you said midbass, I though you were going to use one in conjunction with a midrange which is typicaly the case. 

sedate wrote:

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I already know to avoid metal coned tweeters... what materials would you recommend? I can't grab that article you posted "The Administrator(s) have not granted you sufficient permissions to view the Article Section."

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Metal coned tweeters can be fine because on a good tweeter the resonances are above the audible spectrum.  My comments were mainly for midranges.  My link points to an online magazine where my boss answers different user questions.  Here's a copy of the important parts:

Hobbes26 asked: How do you match tweeters to a given midrange woofer, and vice versa? What main parameters and characteristics must be taken into account? And how does this affect the crossover you build for them?

Number one criteria – bandwidth. The tweeter must play low enough to mate with the mid. Otherwise you’ll have hole in the response. I look for the tweeter to play flat down to the top of the clean response region of the mid, or a bit lower.

Number two: price. Don’t match an $80 tweeter with a $10 woofer – your money is better distributed between the two drivers. Likewise a $10 tweeter usually isn’t worth considering with an $80 mid. Again, spend a little less on the mid to buy a better tweeter. And yes, you typically DO get what you pay for with mids and tweeters!

Next I make sure the tweeter has the same type of sonics as the mid – efficiency (tweeters are nearly always hotter than the mid, so this isn’t too difficult), dispersion around the crossover point, distortion characteristics, etc.

Crossover isn’t too affected – I’m a big fan of high order crossovers. Rarely do I find a tweeter or driver that can’t be easily crossed over. Higher order crossovers not only lower power compression, lobing, THD, IMD, and other issues, but having all those components makes it MUCH easier to equalize the response (called “voicing” if you’re a high end speaker designer) of the driver.

I’m not too concerned with a flat response; I can EQ/voice the response as desired. I’d gladly accept some FR anomalies if the driver has wider bandwidth, or lower compression and distortion.

Hobbes26 also follows up with: What considerations do you take into account when choosing cones/surrounds for a particular driver? Strength? Resonances? Edge treatments? Looks? Profile? How do you find one that's right for the application?

-    Cone must be stiff enough to not break up under maximum excursion. Pistonic behavior on the bottom end, please!

-    Cone should be fairly break-up free. I don’t mind a breakup that is a dip; breakups that are peaks are bad (in terms of sonics, a dip is MUCH better than a peak).

-    Looks should be plain, understated. We sell a LOT of drivers to OEMs who use our drivers in their own products. Having a unique look means it’s easy for your competitors or the general consumers to identify who supplies your driver, and that may not be a good thing. A plain, hard to identify driver is a bonus here.

-    Surrounds should be as soft as possible. I want the stiffness of my suspension in the spider, thank you very much! There’s lots of reasons for this, including linearity, but it also leads to a surround that better terminates edge resonances and reflections of the cone.

-    Edge treatments should be used sparingly, and only when needed. When pushing a 4” cone to 10+ kHz sometimes you HAVE to add some extra damping on the cone. I prefer to put it on the underside, so it’s not visible and doesn’t collect dust, but sometimes you don’t have a choice but to place it on the front (at the surround/cone junction).

-    I go with the old doctor’s maxim: first do no harm. Don’t work with metal cones if at all possible because of the heavy breakup modes. Paper, poly, the softer materials are well damped, stiff enough for pistonic behavior, and in general don’t do anything bad. Some materials do some things better, but always (at least in my experience) have serious flaws. Rather than shoot for an “A” grade in 4 characteristics and a “C” in two others, I’ll go for a straight “B+” across the board.

-    Choice of cone actually depends upon the application. Moving mass, size, excursion limits, bandwidth, radiation pattern, voice coil diameter, basket choice, and price all will guide the choice of cone. There’s no magic choice for all applications – it needs to be made on a case-by-case basis.

sedate wrote:

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  What about the two speakers I posted above? You have any thoughts on those?

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Looking at the CDT speaker, there are some things that concern me.  They say they use stainless steel for their top plate and backplate, which is extremely high carbon steel and has very poor magnetic properties.  In speakers you want softer, low carbon steel.  I tried going to their website to check the parameters to see what the Qes and BL are, but for some reason their website must be down right now.  Here are some other things I notice about it:

"flat spider-allows a consistently linear cone excursion"  Actually you normally don't get a linear response with a flat spider.  Progressive spiders are what provide a linear response.

"frequency response 65Hz-7kHz flat(6.5-octave response)" They don't specify how flat.  I'd really like to see a response curve of that. 

"Sensitivity 92.00 dB (2.83V)"  Note that this is not a 1 watt measurement.  It kind of bugs me when companies rate their speakers like that.

And now the ID mid.  I checked ID's site and unfortunately couldn't find parameters for it there.  However they did give some good information.  One thing to note is that their RE is up at 1.8 ohms, which would make this driver closer to a 3 ohm nominal impedance rather than the rated 2 ohms.  The phase plug might help it have a smoother upper response, but unfortunately they don't provide a response curve. 

Steven Kephart

Adire Audio

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In response to your question regarding the beaming...

ANY driver will begin to beam when you begin to run a frequency through it that is SHORTER than the diameter of the driver. Beaming is really just a reduction of output in the of-axis response, relative to the on-axis response. If you have ever seen a polar response plot, THAT is beaming. (I'll check the 'net and see if I can find one for an example...)

https://www.umiacs.umd.edu/~djue/HP001.AppendixA.htm
https://www.libinst.com/polartxt.htm
https://www.umiacs.umd.edu/~djue/HP001.Wavefronts.htm

Beaming contributes to lobing, which is also explained in the above documents. Lobing is a manifestation of constuctive and destructive interference patterns from two diaphragms reproducing different bands of frequencies. The more a diaphragm beams, the WORSE the "sound power" will be in the space being filled. Sound Power is basically described as "how even is the frequency response in all three dimensions" Are there severe dips or peaks in the response as you move up to down, side to side, or back to front (in the space)? Since there is NO magic driver, that can do 20 to 20K, this is why we use multiple drivers, BUT you'll notice that most often, we sit IN FRONT of them... The car SUCKS for true high-fidelity, simply because of the off axis responses that are so severe to every person in the car. It is impossible for all four people in the car to have "the best seat in the house" - physics don't allow it. The best we can hope for is perfect, full-range response at the center of the car, at ear height (as long as everybody's ear height is the same) and everybody then gets the same amount of shift, beam, combing, etc., etc. All the things that happen while listening to a speaker system off-axis. That's just the way it is, unfortunately.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Steven Kephart wrote:

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[

sedate wrote:

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  What about the two speakers I posted above? You have any thoughts on those?

---

Looking at the CDT speaker, there are some things that concern me.  They say they use stainless steel for their top plate and backplate, which is extremely high carbon steel and has very poor magnetic properties.  In speakers you want softer, low carbon steel.  I tried going to their website to check the parameters to see what the Qes and BL are, but for some reason their website must be down right now.  Here are some other things I notice about it:

"flat spider-allows a consistently linear cone excursion"  Actually you normally don't get a linear response with a flat spider.  Progressive spiders are what provide a linear response.

"frequency response 65Hz-7kHz flat(6.5-octave response)" They don't specify how flat.  I'd really like to see a response curve of that. 

"Sensitivity 92.00 dB (2.83V)"  Note that this is not a 1 watt measurement.  It kind of bugs me when companies rate their speakers like that.

And now the ID mid.  I checked ID's site and unfortunately couldn't find parameters for it there.  However they did give some good information.  One thing to note is that their RE is up at 1.8 ohms, which would make this driver closer to a 3 ohm nominal impedance rather than the rated 2 ohms.  The phase plug might help it have a smoother upper response, but unfortunately they don't provide a response curve. 

---

That doesn't come across very positive for the CDT... huh.  I've read a bunch of message boards.. lotsa word-of-mouth stuff about their HD series of componets.  Out of this world, supposedly.  What is your sense of CDT?  When I learned about the company from my internet travelings, I was delighted to learn they make their speakers in a town I lived in out California ways.  Made me instantly partial.. ya understand.

Yea that response curve claim does seem really odd, especially with what all hamfist discusses above.  I'm still trying to get a sense for what a typical range is for tweeters and midbasses/midranges..  

What is a 2.83v measurement mean? What is it comparable to? I've seen other companies rate thier stuff like that.. I've seen JBL stuff rated like that.  I guess somewhere along the line I figured it was another way of saying 1w/1m but I dunno how to ohms-law 2.83v... since I don't have an amp measurement.

The ID mid looks okay huh?  After I grab that EQX from hamfist I was really thinking of that ID mid and the ID NX30 silk dome tweet for my front end.  That stuff looks wicked to me. The only thing that I was worried about was the lower xover point on the mid than we've been discussing here... I'm *really* paranoid of bright speakers.. I've always been kinda sensitive to that and I've read when you have more sounds coming from your mids that frequently contributes to speakers sounding ...'warmer'... if you will.  From what all you and hamfist have said here, that's a load of crap huh?  Why do *so many* componet sets sound so bright to me?  With an EQ like that AudioControl I'd be able to edit that out nicely anyway though? 

hamfist:

Well lemmie ask ya this then... why come so many competition cars I've seen coming out of the two local performance shops always stack speakers next to each other.. like this:

What is that?  I've seen like 3 custom fiberglass jobs that look *just* like this.  What about the dash mounted tweeters along with it?

From what ur saying that is completely retarded?  Why do they do that? Do they just spend hours with an RTA and an EQ to perfect the reponse b/c it would natively be so peaky? 

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"I'm finished!" - Daniel Plainview

sedate wrote:

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  That doesn't come across very positive for the CDT... huh.  I've read a bunch of message boards.. lotsa word-of-mouth stuff about their HD series of componets.  Out of this world, supposedly.  What is your sense of CDT?  When I learned about the company from my internet travelings, I was delighted to learn they make their speakers in a town I lived in out California ways.  Made me instantly partial.. ya understand.

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Don't get me wrong, it might be a great driver.  I was just commenting on what I noticed on that sales page.  Those are things I would check on to see what is actually going on. 

sedate wrote:

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Yea that response curve claim does seem really odd, especially with what all hamfist discusses above.  I'm still trying to get a sense for what a typical range is for tweeters and midbasses/midranges..  

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Usually you don't want to run a 6.5" driver above around 3k because that's where beaming becomes an issue.  Of course the install will make a huge impact on this.  5.25" speakers can go a little higher though.  Tweeter bandwidth depends on the size and type of diaphragm.  Larger tweeters can usually play lower, but might start to beam within the audible range, or their response might not naturally extend all the way up.  If you try to run a tweeter too low, you will limit it's peak output capabilities.  One way around this is to use steeper slopes. 

sedate wrote:

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What is a 2.83v measurement mean? What is it comparable to? I've seen other companies rate thier stuff like that.. I've seen JBL stuff rated like that.  I guess somewhere along the line I figured it was another way of saying 1w/1m but I dunno how to ohms-law 2.83v... since I don't have an amp measurement.

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2.83 volts supplied to an 8 ohm driver would be 1 watt.  However that same voltage applied to a 4 ohm driver would actually be 2 watts.  It's a way some car audio companies fudge the numbers to give their products inflated sensitivities. 

sedate wrote:

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 I'm *really* paranoid of bright speakers.. I've always been kinda sensitive to that and I've read when you have more sounds coming from your mids that frequently contributes to speakers sounding ...'warmer'... if you will.  From what all you and hamfist have said here, that's a load of crap huh?

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Actually that is true.  Your ears are most sensitive to the midrange frequencies.  And when a speaker system has a boost in this area the speakers will sound more "warm". 

sedate wrote:

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Why do *so many* componet sets sound so bright to me?  With an EQ like that AudioControl I'd be able to edit that out nicely anyway though? 

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It's either because that's how they were voiced, or because of the install.  As an example, our components use a metal tweeter that is very smooth because it was voiced that way.  However if you install the tweeter on-axis it becomes very bright and harsh.  It's because they were desiged to be installed off axis in the bottom of the doors.  The idea of using the EQ when going active is so you can "voice" the speakers yourself. 

sedate wrote:

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hamfist:

Well lemmie ask ya this then... why come so many competition cars I've seen coming out of the two local performance shops always stack speakers next to each other.. like this:

What is that?  I've seen like 3 custom fiberglass jobs that look *just* like this.  What about the dash mounted tweeters along with it?

From what ur saying that is completely retarded?  Why do they do that? Do they just spend hours with an RTA and an EQ to perfect the reponse b/c it would natively be so peaky? 

---

I think those are examples of when form over-rule function.  They care more about how "pretty" the install is rather than how it sounds.  In the top one if both mids actually play the same bandwidth, then you would have nasty comb filtering issues.  The bottom one probably wouldn't be as bad if they used proper processing to fix the lobing issues that would develop.  However depending on how far in the tweeter is mounted, their soundstage would most likely be limited to that width. 

Steven Kephart

Adire Audio

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(Dave nods) Pretty sells... Output... That, and two MUST be better than one, right? Those configurations would have TERRIBLE horizontal dispersion. With a proper application of time delay, (this would require dedicated amplification on each mid-woofer) you MIGHT be able to steer the response around a little but it is never going to sound as good (at least to me) as a well implemented two or three way setup in the door...

In the bottom one, I think it would really depend on:
1. where the crossover point is and
2. it's output relative to the rest of the system.
The above notwithstanding, it is still going to add terrible combing effects to the soundfield. It MIGHT (if that's dash-mounted as it appears) raise the soundstage, but it won't sound really "real", I think. Too many missed and/or summed spatial cues...

First off, I am not a big fan of "surround sound" anywhere, (let alone in the car...) and a quasi center channel of something like that shown above, in the opinion of this reporter, shouldn't sound as good as it looks. (and here I was going to say something here about surround and/or 5.1 in the car, but I don't know enough about it - being a stereo guy, AKA 2 channel, so I'll reserve judgement)

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Those doors look like a modified MTM D'Appolito configuration to me.  A gimick in a car door for sure.  The JL super tweeter may have a function as described above, but again more likely it's a show car gimick.  Show cars are always FULL of gimicks gadgets and gee-gas with little or no actual function.  I once saw a car (forget what kind) that had ten or twelve mids in each door.  The door panel was literally full of drivers.  Looked cool.  The problem was only one was actually hooked to an amplifier so it would create acceptable sound quality.  The rest were there for show.  :)

One other comment: the only place I've ever heard a metal-dome tweet and liked the sound was in a car.  Sometimes they can be a perfect solution for the horrible acoustic environment and road noise intrusion of a car.  So try it before you rule it out, if you can.

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Comment on 5.1 in the car: have Alpines 5.1 system in our display board, they have a demo disc that switches between stereo and 5.1 at 10 sec. intervals on the same track, very impressive. The problem right now/ you can fit the available 5.1 audio discs in a shoebox.

Yeah... That's what I've noticed too... No program material makes it REALLY hard to implement multi-channel well. Stereo recordings need to be played in stereo, and there are not many DVD-A (none that I am aware of) players around to support reasonably recorded multi-channel discs.

That brings up this question: Does anybody here know of a DVD-A compatible car player?

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

My boss wanted to take apart an SACD player and modify it to work in his vehicle.  I thought that would be fun to hear. 

Steven Kephart

Adire Audio

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Alpines  IVA D 301 with the PXA h 701 processer is DVD A compatable. We have it set up with surround sound speakers in our showroom and with Alpine's DVD A disc it sounds pretty damn incredable. Can't wait for the 1/2 DIN center channel gets here.

Has anybody seen my solder?!?

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

haemphyst wrote:

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Has anybody seen my solder?!?

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Give me your number I'll fax you some...

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Support the12volt.com

sedate, I have finished your PFM and crossover modules, as well as sent you your pictures. I was able to get 96Hz (75kohms), and 3600Hz (2kohms). These are standard resistor values available in most electronics stores.

AudioControl can get 100Hz modules, as well as a 3.5kHz modules, if you were to think these are too far off. I have the Owners Manual and Tech Note 1005 all printed out to go in the box with your EQX...

Let me know when you are ready...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Sedate, you still want this EQX? PM me and let me know and I'll hold on to it for you, otherwise I have a friend here at home who has seen it, and decided he wants it now... I told him you were first in line!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."