confusing system setup

hello9, a guy came to me the other day wanting a system installed in his full size 1988 chev truck (extended cab) he wants the seats left in the back, but he's talking about running 2 pairs of subs (2 - 10" and 2 - 12") i'm trying to reason with him to go either 4 10's or spend a little more on the 12", but he seems to be stuck on the 2 different pairs, makeing a proper box for each pair of subs what would the pros and cons be?

now, part two here. the reason he wants to be able to switch between the pairs of subs or have all on at the same time,  mostly for different sound for different occasions. i know i've gotta use relays but i'm not sure where they'd go. and any infor on this would be nice.

here's the setup so far, infinity highs (stock location) infinity amps (one for his highs and one for the subs) i'm planning on running a 2 channel amp and have one 10 and one 12 on each channel so it would be able to run 2 ohm stereo with all speakers wired. and for the subs looking at infinity kapppa perfects 10.1 and 12.1 subs. everyting else has been thought of...i'm just wonding if this setup would work or if my suggestion to him would be better.

the 10's would be in  a sealed box and the 12's would be in a ported box.

-------------
Tri County KustomZ
certified installer

Uhh.

Would your suggestion of NOT mixing sub sizes like that be better?

Uhh yes. Wayy better. For about 100,000 reasons.

I actually had the privelege of hearing 4 Kappa Perfect 10's running off a McIntosh amp. Still the loudest thing I've ever heard.

-------------
"I'm finished!" - Daniel Plainview

What a waste! (unless you are the salesman too). It is just plain ridiculous to have multiple sized woofers in a car, even if they are all not being used at once.  The K.I.S.S method needs to be apllied here.

This guy neeeds to either choose the 10" subs or 12" subs and either a sealed or ported box.

-------------

bobditts wrote:

---

If he wants to have sound quality subs in a sealed box, have him get 8" instead of 10 and keep the 12"s in the ported box. He has the right idea. but he just needs his idea tweaked a little.

---

I disagree with this. First of all you can use a 15" woofer in a sq setup if one felt like it. The size of  a woofer is not going to determine the sound quality. And why would you keep the 12"s in a ported box? Why not sealed? 

-------------

bobditts wrote:

---

for sound quality you want accurate bass. a 15 is a lot less accurate than an 8. yes you can use a 15 for a sq setup, but i wouldnt recommend it. Also, for sound quality it isnt how loud your bass is, so again a 15 would not be optimal. Personally I use a JL 6" sub and it is the most accurate bass I have ever heard. I garantee i would win a sound quality competition over someone with a 15 as there SQ sub. Ofcourse there is much more to sound quality than just bass, but that is a whole nother story.

The reason why i said to keep the 12"s in a ported box is because the original poster said that they would be used for 2 different kinds of music. The sealed subs would be used for rock and other types of music where SQ over SPL would be good and the ported subs would be for rap and other bassy music.

---

Again I disagree. I've used that argument in the past, claiming the 15" or 12" is less accurate than an 8" or 10", but that is in fact a very misleading statement. There are many (15") speakers on the market that can successfully compete with a smaller diameter driver. It is dependent on the motor technology, cone structure and enclosure. For example Adire's Xbl^2 tech, very low distortion. My IDQ's are very accurate and they happen to be fifteens.

But why are you suggesting using two different sized woofers at all? 

By the way do you compete, or at least in the competition scene?

-------------

It's a proven fact that cone size and moving mass have little to do with woofer speed (or accuracy, as you put it, but that's not a good term to use, since no speaker is very accurate). It's the inductance of the voice-coil that dictates how "fast" it is.

To the person that started this thread, everyone, including you is right in saying that the 2 different size subs is flat out dumb. A well designed sub set up could play all types of music acuratly. Also you wont fit a perfect 12 under the back seat of that truck without raising the seat or cutting the floor, so take that into acount.  Now for bobditts, if you say that your 6 inch JL sub is the most acurate bass you have ever heard then you live a sheltered existence. Acurate bass would include being able to play low bass in the 30-40 hz range and your little sub is probally not gonna reproduce that properly. I would also like to point out that 2 years ago when I did SQ competition part of the scoring was being able to reach 130dbs on the mic for full points in that section. Your sub set up would not be able to do that. Dwarren is on the right track. A good quality 15 with the proper power and the proper box will be able to cover the sub spectrum of frequencies much better than a 6 or 8 could, so that would make the 15 a more acurate sub woofer.

-------------
double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

bobditts wrote:

---

For competition purposes I would say Im more correct. But i guess for the everyday joe, you may slightly more correct. Might you be able to back up your statement about the Adire's Xbl^2 tech with some cabinet diffraction response anomales?

---

I believe that cabinet diffraction response or baffle step is a supression of bass due to enclosure width. Not to mention it's not ususlly applicable in a car.

Props to DYohn

-------------

bobditts, from what you are posting I'll have to say you do not know what you're talking about.  Or at least you're not posting things that show you do.  I suggest you back off a bit on the attitude as well.  Thanks.

-------------
Support the12volt.com

I say that it is impossible to hit 146 on a LEGIT mic with that single JL 6" sub. Plain and simple I call bullshhh and say its impossible. I am not someone who is new to the scene and am not one to talk outta my ass. I dont need to hear your specific set up to know that you cant hit that number with that gear because I have used that sub before and know what its capable of. Make sure you know what you are talking about before you call me on something.

-------------
double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Stang, if your customer insists on the two setups for subs, pocket the extra money and let him go on his way.  But he'll need a separate amplifier for each sub setup, and use one at a time, whichever mood he's in.  Put toggle switches on the remote wires to toggle one or the other ON or OFF.  No need for a relay, and there's a toggle switch that has ON at either end and OFF in the middle you could use.

-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

alright, and as i read preavously, i do plan on re-working the back seat, i'm looking into the local laws on what i'm able to do as far as the seat, i beleive i can raise it and make it fit what i need as long as the seatbelts are securly mounted to the stock locations.  i'll mention about running a second amp to the second set of subs. from what i've gathered a pair of infinity perfect 12.1's is going to be plenty loud either way.  to answer another question befor, he listens to alot of the older stuff (brian adams, bon jovi, etc) but then he also like the metal and newer r&b stuff. .

and bobditts, i call bull**** on your 146 setup with a single 6"....JL might make some really nice stuff but i've currently got a pair of MTX 8K 12"s in a sealed box hitting 137.8 (useing the pressure pads) 145.6 (with a mic) ..the day a single 6" sub in a daily driven vehicle beats me at a competition is the day i retire...in a spl competition vehicle with body straps and the works, i wont argue, but not in a daily driving vehicle.

-------------
Tri County KustomZ
certified installer