narrow bandpass xover with zobel?

Anyone know how to calculate a narrow bandpass xover with 4rth order on the highpass and 2nd on the lowpass??
can a zoebel be added??

can I make a 4rth highpass the feed that into a 2nd lowpass??

THANKS

Not sure why you would want that particular topography, but sure.  You want the math, or a website with calculators, or are you looking for someone to calculate it for you?

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Hi, thanks fo the quick reply!!
I want to run my woofs close to the sub, but keep from getting into trouble with the boomies the high end is much less critical

I can do the figuring, no sweat just need the calculators, and a warm fuzzy that I'm covering 20-20K fairly flat.
I do have some q's on the concept of flipping phase on the top half of a L-R xover and how/if that would apply to a narrow pass tri=amped setup IE is there a hole in the response where I change from one amp to the next?

you have PM.

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So you are looking to passive x-over a woofer with a 24db/oct for the H.P. and a 12db/oct for the LP? Curious why these slopes? Why Asemetrical? (Sp?) You are going to have losses due to 3 Coils and 4 Caps plus a resistor (zobel) per speaker.

When you start filtering woofers that low you are looking at some hefty Inductor values. Depending on power, you will need 14 AWG or larger coils to keep down loss. Most likely be an iron core.

Depending on power, Electrolytics' may not cut it for the caps. Teflon, Metal/Poly, or Mylar you are looking at some $$$.

ok

audiocableguy is 100% right, but I'm still trying to figure out what the OP wants to do, even after a few PMs.  meicalnissyen, please describe your plan here for all to help.

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ok
cd5444 nonfader set to 200hz and feeding big amp and pair of alum 8's in nice box
rear outputs to main amp channel 1 and 2 feeding a pair of 8' woofs in enclosures target 200 ~ 1500hz   ,   front outputs to channel 3 and 4 feeding two pairs of 5" sealed back midranges target1500~4000hz and y'ed to the tweet amp feeding a pair of 2.5 cones and 5/8 domes,   cones 4k to 10k and domes 10k and up

I have currently a pair of legacy lxr-7's divvying this up BUT i have a nasty whine I have fought and beat and had come bak I believe it is internal on the lxr's worse in the am when dew is out
I am getting rid of the actives and all the extra wiring

NEED good calculator site
Think zobel circuit on mids a good idea

Welcome thoughts from the group

The above answer from me was based on the "assumption" of a 4 ohm M/B operating from 80hz-400hz with the slopes you said. 24db/oct and 12db/oct.

The H.P. would be 780mF, 750mF, 2.6mH, 15mH.
The L.P. would be 2.3mH, 68mF
Plus the Zobel

I was way off after seeing this:

8" Subs L.P @ 200hz
8" woofers from 200hz-1.5khz
5" x2 Sealed Mids 1500hz-4Khz
2.5" Mid Mids from 4khz-10Khz
5/8" Tweeters from 10Khz

At this point Zobels are least of your worries!

1. The less Crossover points the better, active or passive.

2. The fewer number of different size and brand drivers the better.

3. The last place you want to start dividing frequencies is in the upper vocal range.

This is as far as I'm willing to go.

Good Luck...

I did do the math using partsexpress as a source for pricing. Info provided. 200hz -1500hz.

Solen Std.Caps, Erse Coils and Iron core for the largest coil. $230 per speaker. Electrolytics could be used to reduce costs, the coils alone are $76 per.

A decent amp with an active x-over would eliminate alot of headaches.

Without knowing what specific drivers you are using it is difficult to suggest Xover points, but I completely agree with the above analysis  that your system is far too complex, and that the Xover points you are now using were poorly chosen.  Unless the choices of frequency points were driven by the limitations of your drivers, they are not good ones.  First, get rid of the 2.5" mid-high drivers and reduce the system to a 4-way.  Use tweeters that you can cross at 4KHz or as low as 2KHz . Next, your subwoofer LP should be more like 80Hz and the woofers covering the band between 80 and about 240Hz.  Mid should cover about 240 up to your tweet.  1500 Hz is probably the last place you want a crossover setting.

If your problem is in your active crossover, replace it.  Legacy is crap anyway so almost anything else you buy will be better.  Active filtering will be far more precise, easier to control, and cheaper than trying to build a high-quality complex 4-way passive network.  A 5-way passive filter with the steep slopes you are describing would cost probably $300 each to construct properly.

And in most cases, if the passive crossover is properly designed there is no real need for Zobel networks.  And certainly actives do not need them.

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I agree with nearly everything said so far, with the exception of using iron core inductors. NEVER use an iron core in an audio circuit. Hysteresis distortion is very audible and quite nasty... If necessary, and if BENT on a passive system, use larger gauge inductors, to overcome the losses that are inevitable in inductors of that size.

Also, I'll stop you (hopefully) from using electrolytic caps. Another bad choice you can make. OK in the woofer circuit, they MIGHT be acceptable in a mid circuit, but I recommend a poly or better "bypass" cap to improve their transient capability. NEVER use them in a tweeter circuit.

Three-way is as far as I would ever go in a door. Ever. In a home system, I even prefer two way. The fewer the drivers, the better.

I chose varying manufacturers drivers in my system, but my system (I will admit) is atypical (for a home system - VERY atypical for a car system). For example, my mids carry the brunt of the reproduction in my car, running from 200Hz to 4K. I knew what I wanted. I came up with a design, then I figured on my crossover points based on the -3dB points (on a polar plot), then I chose my drivers to fit the desired crossover points.

I HEARTILY agree with avoiding a (especially passive) crossover point within the vocal band - your desired 1.5K right smack in the middle of it... <shudder> Off axis (which you are VERY much in a car) and unequal path lengths which are also inevitable, that is a VERY ill-advised crossover point. Very. Not to mention the HORRIBLE beaming that a 8" will be doing in the drastic off-axis situation you will be in. An 8" woofer will be a good 12 to 18dB down by 45°. ON AXIS, you can probably be OK, but you can't get that in a car. An 8" to a 5" at 1.5K WILL exhibit terrible sound power, EZPECIALLY with such a steep crossover.

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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."

Ok, I went there with the Iron core. Couldn't find a 8mh in an air core.
If one was available from PE I would guess $75? The difference between the Electrolytic vs. the Solen Metal Poly is $59 each. My direction was toward how cost ineffective the x-over idea is.

Does anyone other than Morel offer a 8" comp set?

Here's an 8 mH... And only $24 each!

Madisound has Goertz Foil Inductors, too. You can get to 8mH with those... At a cost of ONLY $170.00 per side!

Oh, sure... 1.6 ohms DCR, but who's counting!?! LOL (Just bein' a butthead...) However, if I were the one making the choice, I'd take DCR loss over hysteresis distortion ANYDAY.

meicalnissyen, what we are all trying to tell you is that if you REALLY want that complex a system, by the time you spend enough money on passive parts, you could have spent all that change on a really nice active crossover. Granted, there is VERY likely additional complexity and cost in more amps, more wire, tweaking time... But you will end up with FAR better results for your car. I've done it, with an all active three way system in my doors, it wasn't easy, but my efforts (IMO) are rewarded every time I sit down.

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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."

For 8mh you almost have to use a steel core inductor or order a custom (or make it yourself.)  Might be better to rethink the Xover topography and not need it.  I've used steel cores in low-cost systems but only in woofers,  I agree to never use electrolytic caps, you can always hear them.

Quart used to offer an 8" 3-way set, and I remember installing one from some off-brand label like Laser or something once.

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Hmm, the OP must not have liked hearing these answers.  Oh well, maybe someone learned something from the exercise.

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I just listened to a set of DLS Iridium components with 8" woofers driven by Genesis amplification.  VERY nice. 

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For a Kilobuck, I would HOPE so...

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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."

Plus it was in a new Jaguar.  Sometimes you do get what you pat for...

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DYohn] wrote:

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Hmm, the OP must not have liked hearing these answers. Oh well, maybe someone learned something from the exercise.

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Not at all!!
Daddy taught me that while I'm talkin, I ain't learnin !!

I GREATLY appreciate this input

And now I have more specific Q's
regarding the 8" woofers flat on the deck, sealed 0.9cf enclosures extending into the trunk: by off axis, are we refering to the driver bouncing off a curved, angled piece of glass instead of being angled toward my leather recliner and residing in a carpeted room??

I dunno how to fix that, much, a car is a car

I have been listening to the discussion carefully, and realize now I have been borrowing trouble and not stepping back to think

THANK YOU

I cannot drop much bucks (more) into this but I can use what I have much more correctly.

The Xover points I take firmly to heart, with that in mind, how high can I run the woofer ? can I cross it at 4K , and make this a 2 way (plus sub) system??
I am using this driver:
https://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-312
it claims 45~7K

another thought, with my cd5444, the front and rear outs will not see freqs over the nonfader set point, correct???
That being true, I don't need all these expensive chokes we have been debating,   and the issue becomes simply how low the 8" can go without gettin hit by the bump in the enclosure response curve. choices in the head are: 63,125, and 200   AND,... if it can run flat, high enough that I can put in decent tweeters and go two way or if I need to have a mid bass driver set.

with most tweeters saying they go down to 2K, ... will a 2nd order crossed at 4K keep them safe? and would I reverse the tweet polarity to keep phase correct in that setup?

OK... Many more issues revealed with that last post.

Off-axis response refers to the lowering of output in an increasing amount, based on the angle in degrees you are off from zero degrees. (Looking straight onto the driver's radiating surface.) In the image below, the woofer (or ANY driver) is facing out to zero degrees. The concentric circles are dB levels, and as you move inward, the attenuation is greater, or the output is less. As frequency goes up, the output begins to look more like the blue circle. You'll see that at the highest frequency demonstrated in this graph, at 90 degrees (up) and 270 degrees (down) the output for this particular driver is effectively zero. That is "beaming". In this particular graph, the blue circle indicated 40kHz, but it is only for demonstration purposes. The larger the diaphragm, the lower the frequency of the blue line.



A woofer 8" in diameter will start to "pull in" (beam) at a much lower frequency than will a one inch tweeter. The 45Hz-7kHz claim for your chosen woofer is ONLY avaialable if you are looking straight onto the cone.

I'll add more today. I have a gues that JUST arrived.

PS... While researching this answer, I found this page.... Handy. I know *I'm* bookmarking 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."

Woofers in the rear deck?  Ugh.  Here's my recommendation for you.

1.  Set up your subwoofer.  Note the LP filter point you use for the sub (should be somewhere between 70-120Hz.)
2.  If you insist on keeping those Goldwoods in the rear deck, use the crossover built into most amplifiers and set up a HP filter at the same Xover point as your subwoofer LP.  Then either use an external active system to LP the woofer at 240Hz or build a passive for it.  Or better yet, move them to kick panels in the front, or even get rid of them out of your system.
3.  Install a good 6.5" component set in the front.  HP the components using their amplifier Xover at either at the LP of the 8" woofers or if you can them, at the LP of the sub.  Use the passive Xover that comes with the component set as intended by the manufacturer.  Done.

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meicalnissyen wrote:

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DYohn] wrote:

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Woofers in the rear deck? Ugh. Here's my recommendation for you.

1. Set up your subwoofer. Note the LP filter point you use for the sub (should be somewhere between 70-120Hz.)
2. If you insist on keeping those Goldwoods in the rear deck, use the crossover built into most amplifiers and set up a HP filter at the same Xover point as your subwoofer LP. Then either use an external active system to LP the woofer at 240Hz or build a passive for it. Or better yet, move them to kick panels in the front, or even get rid of them out of your system.
3. Install a good 6.5" component set in the front. HP the components using their amplifier Xover at either at the LP of the 8" woofers or if you can them, at the LP of the sub. Use the passive Xover that comes with the component set as intended by the manufacturer. Done.

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Put the woofs in the kick panel?? how bout the pillar instead   ;-)

So, you actually reccomend nothing on the deck, and in essence, a nice 6.5 set in the doors handling everything the sub passes

meicalnissyen wrote:

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Put the woofs in the kick panel?? how bout the pillar instead   ;-)

So, you actually reccomend nothing on the deck, and in essence, a nice 6.5 set in the doors handling everything the sub passes

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Yes. 

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And I CANNOT believe how much infrasonic information I was losing through my roof! Two layers of Dynamat Extreme, and a layer of aluminum lined cotton felt later, my bass is even deeper and tighter than it WAS! (That's what the guest was coming over for... we were damping my roof today.)

Oh, and the AC works even BETTER now, too! (This, due to the insulative properties of the applied materials.)

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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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And I CANNOT believe how much infrasonic information I was losing through my roof! Two layers of Dynamat Extreme, and a layer of aluminum lined cotton felt later, my bass is even deeper and tighter than it WAS! (That's what the guest was coming over for... we were damping my roof today.)

Oh, and the AC works even BETTER now, too! (This, due to the insulative properties of the applied materials.)

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the M1A1 abrams has a much stiffer cabin, might be a good choice for competition