Rear Speakers

From what I understand, the front speakers are supposed to be the ones doing most of the work and the rears are only supposed to be helping out a little. If this is true, is there a point in buying another 2 channel amp or going with a 4 channel to power the rear speakers too or would it be fine if I just ran the rears off the head unit?

The point for me is to get the extra stress of powering the speakers off of my HU's circuitry and let the HU concentrate on delivering a good clean signal to the amps. The end result is to get better sounds with less distotion at mostly all of the volume settings.

If this is true, is there a point in buying another 2 channel amp or going with a 4 channel to power the rear speakers too or would it be fine if I just ran the rears off the head unit?

Running the rears on the headunit is perfectly fine, in fact if people insist on running rear speakers at all this is what I tell them to do. I've had a 4ch amp giving all the speakers the same amount of power and it's just a waste of money. Spend this money on better front speakers, not on more power for the rear that you'll never even come close to using.

The point for me is to get the extra stress of powering the speakers off of my HU's circuitry and let the HU concentrate on delivering a good clean signal to the amps. The end result is to get better sounds with less distotion at mostly all of the volume settings.

that must rarely happen because i've been on so many forums and no one has ever complained about that.. also its ok to run off head unit power.. but once you get past 65% the head unit amp should start clipping.. which creates distortion.. i duno wat the hell ur talking about the head untis circuitry or whatever.. i always delievers a clean preamp out signal unless somethign is wrong with the rca cable or you have the gains wrong

also i have non of my speakers run by my head unit.. i amped the front and back.. sending 87rms to each one.. sounds great even for 60rms speakers

some people get distortion and think they're at their limits, other people think about cleaning their signal flow. one way is to use separate ckts (componets) for signal processing and amplification. it doesn't take much to induce noise into ckts that uses signals that small (.500mv -4v is common). i think of every phase of every system i build as a future reference system. but thats just me i guess

I'm a big fan of not using head unit power as well... my thinking isn't necessarily to 'free the head unit of extra responsibility', but more to keep the temperature down (using the head unit's amp will heat things up in your dash). I think discrete amplifier power is better, I refuse to believe you can pack 50w x 4 (common claim of most head units nowadays) into that tiny space and get true clean power out of it...

yep, 50w x 4 is really more like 22w x 4 (roughly) true RMS... not really enough to do much with...

I don't like headunit power, personally. I wonder why alpine's new line (the 98xx series) all have built in power, to me it's just a waste

Yea, but if I can go without buying a more expensive amp just to power the rear speakers and not sacrifice the overall sound quality, whats the point?

are your rears stock?

No, my stock rears blew out so i replaced them. Didn't put in anything fancy, just a pair of boston acoustic fx's. I know now that I shouldn't have wasted money on rear speakers until getting better fonts, but its too late to change that. The fx's can handle more than the head unit can provide, but i just dont want to invest anymore money in a already bad decision.

No, my stock rears blew out so i replaced them. Didn't put in anything fancy, just a pair of boston acoustic fx's. I know now that I shouldn't have wasted money on rear speakers until getting better fonts, but its too late to change that. The fx's can handle more than the head unit can provide, but i just dont want to invest anymore money in a already bad decision.


how do you figure rears are useless, even if you crossover your fronts perfectly with your sub, the best you can hope for is half the sound half as full w/out rears. if switch your a/v outs on your HU to the front a/v outs you can fade from front to center w/out losing subs. It won't take long to see what you'll be missisng

how do you figure rears are useless, even if you crossover your fronts perfectly with your sub, the best you can hope for is half the sound half as full w/out rears. if switch your a/v outs on your HU to the front a/v outs you can fade from front to center w/out losing subs. It won't take long to see what you'll be missisng


are you saying that with only front speakers you will only get half the sound.......wtf!?!?

i say run them off the head unit for now. then save up and get components in the front. then save up again and get a 4-channel amp. or u can get them at the same time if u have enough. do what ever you want. u dont have to get an amp right this second, but i would eventually. thats just me though.....

Midbass transition
For sub-bass to sound natural, the system must have good midbass capability as well. These two are interrelated because harmonic components of the sounds produced by instruments that play in the sub-bass range must be accurately reproduced in the mid-bass range for a system to sound accurate.
In car audio, we normally don't have the luxury of using very large drivers to reproduce midbass. For this reason, the ability of a subwoofer system to smoothly transition to the mid-bass region becomes very important to achieving top-notch fidelity, (enter front 6's rear deck 6x9's or if your fortunate 8's). How I see it, (and the folks at JL Audio), from sub to rear to front it's all a piece of one sound. If you take from the system your taking from the sound.

Navy .... I am not following your logic at all - I suspect a nimber of other people aren't either. If you have rear mid/tweets playing at the same volume as the front mid/tweets, you will only see a 3 dB gain (if I remember that correctly) then if you just had the front set. Not a huge gain in SPL, and will be a BIG loss in quality since your front sound stage will totally collapse. Midbass however, has always been a problem in cars. As you have pointed out, most components (but not all) have weak midbass response. And I think what you were trying to say is that the harmonics of the bass are in the midbass region. This is very true, what makes most systems have good or sloppy bass is actually the response in the midbass region. I laugh when people refer to "sq" subs ..... if you doubt me, pull the fuse on all your other amps and just have the bass speakers play. You will understand VERY quickly how bad a plain sub sounds all by itself, and the "sq" is not really a major consideration. Mostly it's just trying to get a smooth response in the bass, meaning no major dips or peaks.

damn PaulD, you say you don't follow, but you right on point. in some cars i guess you can get away with only fronts, but they gotta be kickass fronts like F#1Status or something. Then again, just because it could be done, that dosen't mean I'll recommend it.
you know, I can drive my car with my feet, but wtf...:wtf:, I won't recommend it

I'm dropping my car off tomorrow, it should be done by friday (wish I had time to do it myself). I already got a couple of alpine spr-6 1/2" componets up front and spr-6x9's in the back deck with a cda-9800 series HU, and a JL300/4. I just traded up my 500/1 and spec box, but I'm keeping the sub (12w7) for a 1000/1 and some more custom work.

so basically what ya'll tryin to say is i can yank the fuses's from the 6x9's and i shouldn't even notice. yeah ok, my sh?t already drown them muthafuckas when I really push 'em, as a matter of fact when i get back from iraq (about this time next year), i plan on getting another 300/4, some custom work over the map pockets, and a set of F1's in each door. That might hurt the kitty a little, but fuck it I'mma still try and swing another 1000/1 and 12w7...

I tried the midbass driver thing as a "what do I have to lose". I had a set of 6 1/2 drivers in my door, part of a boston acoustics 6.2 pro component set. Yea, you can tell by the .2 that this was 10+ years ago. When I converted to kickpods, I got a pair of 4" midrange speakers for them. I already had the 6 1/2's in the door, so I figured why not try it as an experiemnt. I think I need to use 8's though, like I did in the accord. I can't emphasize how important having good midbass is to a good stereo.

Navy, have you ever even tried a setup with no rear speakers and quality fronts instead? It sure sounds like you haven't, because everything you say about the lack of midbass or volume is just a blatant assumption. There are a TON of component sets out there that can keep up and transition well with a sub. I have a set, and guess what, they aren't F1s.

If you take the money that you're spending on rear speakers and a 4ch amp instead of a 2ch, you can get a single pair of components 2-3 models up than you would have got before, and this single set will have arguably more midbass and more volume than all 4 of the lower level speakers would have, this I promise you. Not to mention, when you run this single set of components, you don't massacre your soundstage by having half of the sound coming from behind you. I honestly can't stand riding in cars with rear speakers now, it's so distracting, it keeps making me want to turn around because it doesn't feel natural. People think it's weird going to 2 speakers instead of 4, but all it takes is a day at the most. Going back to 4 speakers takes forever because it just sounds so screwed up.

Have you ever seen a true sound quality car with rear speakers? Just some food for thought....

my question is (sorry, im still learning) why do the fronts work harder than the rears. why dont they both produce the same. this doesnt make sense to me because the rears are either the same, or sometimes bigger. please tell me why the fronts work harder and the rears only help out!!! thanks

Navy, have you ever even tried a setup with no rear speakers and quality fronts instead? It sure sounds like you haven't, because everything you say about the lack of midbass or volume is just a blatant assumption. There are a TON of component sets out there that can keep up and transition well with a sub. I have a set, and guess what, they aren't F1s.

If you take the money that you're spending on rear speakers and a 4ch amp instead of a 2ch, you can get a single pair of components 2-3 models up than you would have got before, and this single set will have arguably more midbass and more volume than all 4 of the lower level speakers would have, this I promise you. Not to mention, when you run this single set of components, you don't massacre your soundstage by having half of the sound coming from behind you. I honestly can't stand riding in cars with rear speakers now, it's so distracting, it keeps making me want to turn around because it doesn't feel natural. People think it's weird going to 2 speakers instead of 4, but all it takes is a day at the most. Going back to 4 speakers takes forever because it just sounds so screwed up.

Have you ever seen a true sound quality car with rear speakers? Just some food for thought....

well it's been about a month, and because of this thread, I decided against the Alpine setup and went with the Pioneer HU and Infinity components up front. I didn't get rears, I wanted to give the front stage a try after I heard one of the local installers Mini Cooper w/the same setup along w/the what I got to lose thing from this thread. He had a bigger midbass (8") driver in his 3 way comp setup in the doors, and a smaller dub7 (10") than mine. needless to say his sh?t is way more seamless than mine. but I do get the point ya'll was making, it's just not for me. I got another thread (rear fill) asking for advice from anyone who knows...

I don't like rear fill, went with EF-61s and got some 1" tweeters from CDT, sounds better than any rear fill system I have ever heard. I have no substage due to a lack of amp, but my sub sounds good right now. Honestly I don't miss my sub yet... maybe if I listened to rap, but I don't. I am slowly starting to miss my bass in my car after hearing it in my HT...

well it's been about a month, and because of this thread, I decided against the Alpine setup and went with the Pioneer HU and Infinity components up front. I didn't get rears, I wanted to give the front stage a try after I heard one of the local installers Mini Cooper w/the same setup along w/the what I got to lose thing from this thread. He had a bigger midbass (8") driver in his 3 way comp setup in the doors, and a smaller dub7 (10") than mine. needless to say his sh?t is way more seamless than mine. but I do get the point ya'll was making, it's just not for me. I got another thread (rear fill) asking for advice from anyone who knows...


You're probably missing a good bit of info between your sub's lowpass and 150hz, infinity components aren't exactly midbass monsters. Actually even if you got rears, you would still be missing that key area. I had infinity kappa comps in the front and coax in the rear and it was definitely lacking, I think this might be your problem, not that you're just running fronts. Just for reference, the focal polyglass comps (with no rears) that I switched to from the 4 kappas had way more midbass than the 4 kappas had, and then when I went to the kodas, ONE koda (just the driver's side) hooked up killed the pair of polyglass that I had in midbass output, then once I put in the right side as well it was like heaven.

You have a choice now though, if you feel something lacking you can either get rears and see if that fixes it, or get a better pair of front speakers and see if that fixes it. You know what I did with my setup and how it turned out, but you'll have to do what you feel is best, good luck

kodas..can you elaborate a little more? who,what and where can I hear some...

Adire audio makes kodas. My CDTs run great on their mid range I have them running 120hz up. They are the EF-61 series. I don't feel a need for a sub right now...

I have mine x'ed @ 90hz, and my high levels adjusted to match my sub level at 125 hz at normal listening volume. they're loud, but neither one of them are full enough for me...

you should have your sub set as low as you ahve your mids... otherwise they are fighting...

yeah, www.adireaudio.com for the manufacturer's site or www.acoustic-visions.com for a place to purchase

I have mine highpassed at 50hz on a 12dB slope and they love it

Adam... I am probably going to have my CDTs highpassed at 90-100 on a 12db slope. Think my XXX can cover the ranges below that well?

probably, might want to use a box on the small side though to help out the upper bass. I like to have my subs crossed over at 60 or below personally, anywhere above that and it starts becoming localized, and that just irks me pretty badly.

See my only problem is my midbass doesn't have enough room to move as much as it really needs to to be crossed over lower. I was going to go 4 cubes tuned to 35hz... I have heard smaller boxes dont sound well with a XXX...

that may be true, I haven't done all that much research on the xxx so I'm not sure

Ok... I think I am going to stay with my large box and hope for the best... If I have to cut out the front of my doors and move the mids... I guess I will

if your midbass is poor, you might need a dedicated midbass driver. Now that I have done the stereo in the accord, I can think about what I want to do in the CRX. It will be either 8" or 10" midbass in each door, placed as far down and forward as possible. The sub will probably be a 15" brahma in the hatch area. I will stick with the Focals for mid/tweets. I know there are lots of diferences in the two systems, but the focals sound so much more open in the midrange.

for midbass, Adire just released the koda 8, might be worth looking into

http://www.adireaudio.com/TextPages/Koda8PageFrameText.htm

edit: looks like you already saw them, guess I'm just a whore....