Printer Friendly Forum Posts - upgrading system?

Based off another question i had asked i've determined that i'm going to have 2 15s in my trunk/back seat area, the next thing i'm wondering is if a pair of 8s to replace the factory speakers would be a good idea or will the 15s and 8s cause cancelation problems with each other? i'm planning to run sealed boxes for the 15s and probably the same for the 8s, i was also going to move the 8s so that they are mounted to my rear deck above the seats in the back window of the car by cutting a whole glassing a set of speaker rings to the deck itself and building boxes on the lower side so they look pushed thru from the bottom, i'm trying to keep the subs facing the trunk, but i may face them forwards behind the back seat as my seat drops down, i'm also planning to upgrade the front speakers with a component system, and possibly another set of 8s in the doors, now is all this just really far overkill or would the 8s make a noticable difference? also i'm going to run adire audio 15s, with their 8s be a good choice as well?

yes they will make a smoother transition from the 15's to your comps if they are 6's or 5's. they will cause cancellation probs and sound bad unless you find the right frequencies to cross them over. unless you have a good understanding of crossovers, or are willing to do a lot of trial and error, i would suggest not doing that. a 10" might be better suited than an 8" as well.

I don't know if you will be able to fit 8's easily into your rear deck. If it isn't hard at all I would try it. RE, Adire, and JL make some pretty good 8's. I don't think it would be that hard to do with crossovers. It would be simpler to just buy a crossover from Audiocontrol that lets you send a signal to your 8's, front components, and subs.

so could i run a 10" with the 15s and not have cancelation issues? i dont mind tweaking things, i planned on an eq and a couple crossovers for the system already, i also do fiberglass work and am quickly picking up a vast knowledge of modifications to electrical and mechanical parts of my car, also i have around a 100 watt alternator in my car and a red top battery, i'm planning to upgrade to a yellow top under the hood, and possibly a second one in the trunk for the audio system, now if i buy 2 yellow tops i dont need an isolator correct? i'm also planning to upgrade the charging wire to 0ga and the main ground to 0ga as well as a 0ga wire between batteries fused of course, am i forgetting anything with that setup? i'm hoping to run 1 to 2 amps for the subs in the trunk and a 4 or 5 channel amp for the in car speakers, i'm also planning to run 4 ga power wires, now this should allow me alot of flexibility in my amp choices shouldnt it? my other question is if i have a second battery in the trunk i'm going to ground to the chassis of the car/body of the car, the audio system will also be grounded there do i need to keep all my grounds centralized i.e ground the battery and all amps to the same spot or can i ground the battery on the left and all the others on the right and not have issues with sound quality?

you should be good. do make sure you ground everything, and i mean everything to the same point. try to do it in the middle of your car so if you have a ground loop and need to run the decks ground to the same point, it will not be too far. you really wont need a second batt unless you want to ahve your system on when your car is off. and no, you will not NEED an isolator with 2 batts that are exactly the same. wouldnt hurt

will a distribution block work for grounds?

also how should i go about selecting a fuse for my power wire from the battery to the back of the car?

I don't like Bullman's advice here at all.

I think a MUCH better system would be this:

Forget about the 10". It will cause cancelation and add very little if nothing to the system.

Forget about the 8" drivers in back. Midbass should not come from the back.

Once you have the 15"s in there concentrate your efforts on creating a seamless transition via the front stage.

Here's what I'd do:

Put 5.25" or 6.5" components in the kicks.
Put a 6.5" - 8" midbass in the doors.

Take the 8" drivers out of the back competely. Let the subs in the trunk breath through these holes.

Cross things over like this:
Sub: to 80hz.
Midbass: 80hz to 150hz.
Components: 150 up.

See. No overlap. No worries about cancelation. Everything will correctly sound like it is coming from your front stage. The midbass drivers will help you obtain a nice blend to the subwoofers.

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New Project: 2003 Pathfinder

A distro. block is great for the grounds.

See the link Power and Ground to the left of this page.

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New Project: 2003 Pathfinder

man your just full of good info aren't ya lol, wanna recommend some good 8s for the doors, and component systems? as well as a good brand for crossovers and possibly an eq? i like that setup much better i had always heard that mixing 10s 12s and 15s will cause cancellation because they run in such close frequencies to each other, i've also heard let the bass come from the back and the highs from the front, now if i flip my subs to the front and build an enclosure, what do i need to do to make the bass sound clean and tight? i've heard that you have to foam/block off every hole and opening between those 2 areas so whats the real story behind this?

Adire Koda 8's for the doors definitely....I wouldnt suggest RE8's because they serve more as a subwoofer than a midwoofer...I really cringed at the idea of someone suggesting a 10" in there..bah. I like kfr01's advice so far.

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Dave

Pioneer Premier DEH-P660
15" Kicker CVR
Profile AP1000M
It's Loud

ya i gotta agree withthat one about the 10, anybonus that a 10 could possibly provide would be pointless with the tempest 15s i'm planning to use, gotta thank kfr01 for pointing out those subs on another thread, adire is looking like a great company from their performance specs and the numbers users are posting, i dont know a whole lot about re i was interested in them for awhile but they are massive subs, from what i'm reading i think the brahma 15s will be my next step up if i ever need it, plus i recall reading that the adires have a 3 inch mounting depth. can i just free air them in the door? or do i need to seal of0f the door?

kfr, for once i am going to have to disagree with you. i think it is pointless to put an 8 with a 6 when you are going from a 15. i wouldnt cross the 15 over any higher than 60 hz. i would then take the 10s from there to 120. its going to be a little hard on the 6's, but at a normal volume will sound much better than forcing a 15" sub higher than it should be or making the 8s go lower than they should. the 10s would also be good for days when you dont feel like rattling you eyeballs out of their sockets. personally i would have 8's in my door as well, but i think two 10's in the back would be the better of the 2 sq compromises. thats my opinion because i think a car audio sub over 12 inches sounds like a** in the higher bass frequencies.

bullman96..you're generalizing things way too much here. The Tempests provide excellent sq while getting loud..it's what they do man..If you want better sq you could look into the Atlas 15..features xbl2.

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Dave

Pioneer Premier DEH-P660
15" Kicker CVR
Profile AP1000M
It's Loud

how am i generalizing, i dont think an 8 can get down to 60hz very well especially matching the volume of a tempest. have a 15" sub above 60hz. the sq below that frequency is amazing. ive heard it, no arguments there. but a 10 would cover the frequency range better. the only reason that i wouldnt use two 10's would be for imaging because they would have to be in the rear. i think that is a better sacrifice than to deal with the gap between the 8 and 15. so dont say my opinion sucks and not back it up. who is generalizing?

bullman96 wrote:

how am i generalizing, i dont think an 8 can get down to 60hz very well especially matching the volume of a tempest. have a 15" sub above 60hz. the sq below that frequency is amazing. ive heard it, no arguments there. but a 10 would cover the frequency range better. the only reason that i wouldnt use two 10's would be for imaging because they would have to be in the rear. i think that is a better sacrifice than to deal with the gap between the 8 and 15. so dont say my opinion sucks and not back it up. who is generalizing?

So your argument is this:

1) that the Tempest cannot reach 80hz cleanly on the high end; and
2) that a 8" driver cannot reach 80hz cleanly on the low end.

No offense, but that's just wrong. There will be no gap. You are generalizing. Here's why:

1) The Tempest isn't your regular cheap 15" car subwoofer. It has smooth frequency response to 200hz! Check the lengthy specification pdf. Otherwise I'm sure Steven will back me up on this. What makes your generalization even worse is that MANY 10" car audio drivers have earlier break up modes than the Tempest.

So, we've solved that. The Tempest will easily and cleanly reach a 80hz crossover point. I have absolutely no concern here.

2) What? MANY good 8" drivers will reach 80hz. Good ones will reach 60. The Koda 8 is a prime example. It can comfortably be crossed over at 50hz. See Adire's Koda 8 specs. Many other 7-8" drivers can be crossed over at 80hz quite successfully.

I have absolutely zero concerns about the system I suggested covering the frequencies I suggested.

Anyway, please know I'm not trying to be a jerk, I actually quite enjoy defending my position. :-)

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New Project: 2003 Pathfinder

Bullman, I agree with those who think you're generalizing about the abilities of the certain woofer sizes. Any 15" can play much higher than 120 Hz, and any 8" (or 6.5", as a matter of fact) can play much lower than 80 Hz. You don't need to transcend frequencies with drivers that step up in sizes in the steps that you are describing. I didn't hear kfr01 say your opinion sucks...you shouldn't assume that's what he meant. This is a discussion forum. We have to all remember that when another member disagrees with our advice. It's up to the author of the thread to make his final decisions. Actually, some of the best threads I've seen started out as disagreements, and everybody benefits.

i'm enjoying watching this battle of opinions, both ideas sound nice, but in my car i feel that kfr01s' setup will maximize the sound stage nicely, i have a cavalier coupe, so my space is limited. i'm curious about somethin with amps, if i run 2 speakers say to dvc at 2 ohm wired so they show a 2 ohm load and power both of them with a 1000 watt@ 2 ohm amp how much power is each sub actually seeing is the 1000 watt supplied to both subs are is it split between them? i've never read anything to answer that question before.

i'm enjoying watching this battle of opinions, both ideas sound nice, but in my car i feel that kfr01s' setup will maximize the sound stage nicely, i have a cavalier coupe, so my space is limited. i'm curious about somethin with amps, if i run 2 speakers say 2 dvc at 2 ohm wired so they show a 2 ohm load and power both of them with a 1000 watt@ 2 ohm amp how much power is each sub actually seeing is the 1000 watt supplied to both subs are is it split between them? i've never read anything to answer that question before.

Tempests have dual 8-ohm voice coils. Wire them parallel-parallel to achieve a 2-ohm load at the amplifier.

The 1000w @ 2ohms will be split between them. 500 each. 1000w is slightly over their RMS rating. Because of their excellent efficiency, you don't need this much power to rock them. The practical gain over a 500w @ 2-ohm amplifier will be minimal. That said, if you have the money and your electrical system can handle the amplifier, go for it and be careful about running them too hard. Although the Tempests are underrated, depending on your box you could still push excursion near its limits with 1000w rms to the system.

https://www.memphiscaraudio.com/products/details.asp?id=24

Would be an excellent amplifier for these subs.

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New Project: 2003 Pathfinder

the 1000 watt was just a number for my question, i'm planning on running alittle less, probably somewhere around 400 watts to each sub, i want them to be loud but not to tear themselves apart, also have to be able to get the rest of the system to blend, it was just a theoretical question, but actually if i was to run 1000 watts to the sub adire claims their max rms at 750 watts 400 watts to each coil, so 500 watt to each would be about right, also are memphis crossovers as good as their amps? and i've got a sony md850mp i beleive thats the model number, i know its an 850mp something or other, flip out motorized face and such, i'm just curious if i should upgrade this as well or will it be fine once i upgrade everything else? also are alpine headunits pretty good? what about pioneer head units? also what are some good brands for lcd screens?

also what is good to use for sound deadening in the car? is the dynamat spray on stuff any good? what about any other brands of spray on, as well as sheets of sound deadner?

Oh, that 750w is pmax, not RMS. RMS is more near 500w, if I remember correctly. Either way, those subs can take a beating. Your 400w to each sub sounds perfect, but again, the practical difference between 800w and 500w is almost un-noticable.

I would feel confident trying anything from Memphis.

I feel the best value in head units is Eclipse. Run a search and you'll see that many agree - and many disagree too. :-) This is a matter of opinion. Alpine and Pioneer make good stuff too.

I know nothing about lcd screens. I have never tried in car video.

I have tried a lot of sound dampening products as my car is horrible for wind and road noise. The best value I found was from https://www.raamaudio.com/ It compared favorably to Dynamat Xtreme for much less money.

I have not tried the spray however, it just seems messy to me. :-) Perhaps someone else can shed light on this one.

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New Project: 2003 Pathfinder

thanks again, i'm just gonna start asking you questions lol, kinda like the forums cause theres so many ideas but on this one you've come up with a nice solution for my car, and a ton of good info to go with it, one last thing i'm curious about and i dunno if anyone will have a good answer for it, i'm currently trying to polish my amp, its an aluminum case that had a finish on it that i took off and got it shiny, now i actually want to polish all of the fins and flat areas on the top, all the circuits are mounted to the peice i'm polishing, will this hurt them at all? also i'm going to paint in between the fins black will this hurt anything as this amp doesnt usually get that hot its only about 100 to 120 watt amp?

also what about jl audio amps? are they as good as they seem or just over priced?

after rereading your last post, if i power these subs with say 300 watts apeice they will still hit as hard as 400 watts? pretty cool if thats what your meaning especially since a 600 watt amp is much cheaper than an 800 lol.

These subwoofers are very efficient. They will get extremely loud with a couple hundred watts. I really want to stress this. Since you have the room to dedicate your entire trunk you are a lucky guy. These 2 Tempests with only a 600w amplifier will challenge, in terms of SPL, 2 Brahama 12"s with a 2500w amplifier.

Here's a nice little rule to use when deciding how big an amplifier to buy: It takes a doubling of power to increase maximum SPL by 3db. 3db is small. +10db is a doubling in volume. So, if you're looking at a 600w amplifier, you'd need 1200w to increase max spl by 3db!!!!

The difference between a 600w amplifier and an 800w amplifier will yield a max spl increase of just over 1db. A 1db difference in max spl will barely be noticable 99% of the time. Not worth it in my opinion. That said, get 800w if you want to extract every last db out of the woofers - it might matter in competition.

My opinion is that Memphis and JL are of similar high quality and that Memphis is the better value.

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New Project: 2003 Pathfinder

600 watt will be just dandy for my needs, i've never heard the break down on what watts actually translates into noise, kinda neat to find out all this stuff, whats the general rule about rms on a sub/speaker vs rms output of an amp? do they need to match or will a 200 watt amp pushing a 400 watt rms sub still translate into good power? basically how much power vs rms on a sub is required to get good sound from that sub? as for the 15s, which way will yeild the best results in a coupe type car, if i build the enclosure to face the rear trunk area, or if i build it to face them forward? since i work with fiberglass i'm going to build 2 wood boxes and put fiberglass fronts on them, either pushed forward into the space behind my seats, or facing the trunk lid, with the amp in between them, also i knew a guy who did all his own stereo installs and most of them were pretty good but he claimed that you could not mount an amp upside down because it wouldnt work right anymore, i'm guessing this is a bogus claim but i wanted to know if there could be any truth to it at all.

also i'm planning to run an airride system on my car in the future, do i need to ground the compressors to the same spot as all audio sources or should i make a seperate ground? thanks in advance to kfr01 and thanks to all the answers i've gotten so far.

The general rule (very general) is that you should try to get them reasonably close. Some people say amp rms should be at least 75% of speaker rms. These 'rules of thumb' mean little, I think.

They do not need to match. There is absolutely no difference in _sound_ between running 100w to a sub and 1000w. The only difference is in max low distortion spl.

With only 100watts total (50 a piece) to your 2 Tempests you'll push around 113db before cabin gain. This is really loud. From here add 3db for every doubling of power. So, 116db at 200w. 119db at 400w. 122db at 800w. This is about the max, you won't be able to double again safely. Remember this is only MAX SPL that it effects. Everything below max spl will sound exactly the same. So you see, there's really very little max spl difference between 400w total to these drivers and 800w total. Only 3db. This might matter at the competitions when machines do the measuring - but you'll rarely notice much of a difference.

I'd try facing the subs toward the trunk lid first. I've always gotten the best results this way.

On mounting the amplifier upside down. It depends on the amplifier. SOME amplifiers only have heatsinks on one end. They will not cool correctly if you mount them upside down. It depends on the amp.

I know nothing about air-ride systems. I'm just an audio guy. :-)

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New Project: 2003 Pathfinder

i was mainly curious if the compressors grounds would cause a ground loop in the few times that they would happen to kick on the same time the subs were pounding, i guess i could just deal with it lol. again thanks for all the help, one last question assuming i just want an spl sub, what would be a good sub for high spl numbers? as well as your thoughts on diamond audio amps, kicker amps, lightning audio amps and planet audio amps and subs :).