Anyone good with car audio?

[RC10th]

I just bought a new head unit, 4 channel amp and amp install kit. Needless to say I'm a bit miffed on which connection diagram suits my set up best.

At the moment I only have a 4 speaker set up but would like to add a sub in the not too distant future. One audio shop said to run the front two speakers off the head unit and bridge the parcel shelf speakers and bridge the sub.

Another shop said to run all 4 channels independent.

From my understanding bridging increases the power output, which is confirmed by the max power output specs in the manual

What set up would best suit my 4 speaker system + sub?

Head unit is Pioneer DEH-X3750UI
Amp is a Pioneer GM-A6604


Are RCA connections better than the speaker wire connections to the amp? If so I need to buy another RCA cable as my head unit has 2 pre outs.

I should mention back in the USA I had a shop install my last system and while nothing extreme it was killer. Sound was crystal clear crisp and low end bass was good but not overpowering. I would like to hopefully acheive similar results.

[scr8p]

What about sending the 4ch amp back and getting a 5ch? You'd have 4 separate speaker channels and 1 for the sub.

[RC10th]

5 channel amps start to get up there in $$. I could probably get a mono amp just to run the sub for less than a 5ch amp. Or like the one shop said, run front speakers off the head unit and bridge the rear speakers and bridge the sub.

[jwscab]

It looks like you can set the HPF/LPF on channel B. If that is the case, I would run the front speakers off the head unit, and use the amp from the rear head unit channels as a 3 channel output, two to the deck speakers and one to the subwoofer.

[RC10th]

To use channel B requires another set of RCA cables. I should have bought another when I bought the install kit but didn't realize it only came with one.

Using it as a 3 channel output on channel A with non subs = 120w RMS and on channel B with subs is 180w RMS. With the filters on B this sounds like a good idea, plus using the head unit filters for the front speakers would help with sound quality.

50w from the head would be peak so who knows what the RMS is, but is this enough for the front? I assume 180w RMS is enough for a sub, would this be a balanced system?

[RC10th]

Another thing I was about to buy some new Pioneer speakers but decided to hold off as I wasn't happy with the tinny sound on the sound board. I was pretty set on a couple of them due to their extremely high ratings from many different reviews, but was dissapointed.

A cheap $99 pair of Kenwoods walked all over the $159 Pioneers.

[jwscab]

I would think it would be decently balanced. don't forget the fronts are essentially high/mids, and the total rms power is less important(doesn't take as much power to get the sound pressure). whereas the subs need the kick, and in this scenario, you get it.

unless everything is completely boxed up and sealed, it's essentially already considered 'used' it can't hurt to try, at least temporarily mounted to see how it sounds.

[j-sou]

If you're going to add a sub, I would bridge two channels for the sub, and use the other two channels to power the front speakers (not bridged) while running the rear shelf speakers off the head unit. Not sure why everyone keeps saying to run the rear speakers off the amp. You sit up front, that's where you want all the power and sound quality. The rear speakers are just fill. Do you have some decent components or 2ways up front? A 5 channel or separate sub amp would be ideal, but that's the way most people do it with 4 channels and a sub.

[alien3t]

most shops have told me that with 2 outputs. the end up running sub on rears. amp front rcas to front front speakers.

Maybee see if there is a rca splitter. so run one to rears. than later get a sub and a sub amp and split from the rcca

or a new headunit with 3 sets of outtputs?

If run 4ch amp to fronts, and res tot rear. as you crank it up . front speakers will work great with amp. but might start straining rear if ran with no amp. and wont tell over the sub.

[Kyoshojoe]

I think you would be better off getting a pioneer headunit with 4 preouts and internal crossover filters, this is better because you can either use them for full range fading or mid/high and sub split. your signal will be cleaner as well because the signal will be split before the preamp and essentially create less noise and distortion vs the filters in the amp. you also get centralized system control and tuning.

Are RCA connections better than the speaker wire connections to the amp?

Using RCA signal lines is definitely absolutely no question 10x better than speaker level input.

don't forget the fronts are essentially high/mids, and the total rms power is less important(doesn't take as much power to get the sound pressure

This is a very common misconception and can be argued total opposite, volume and sound pressure are separate entities, as the frequency increases the effect of pressurization exhibits diminishing returns to the point of negligibility but volume or decibel level still increase. also consider mids and highs in their nature are more temper-mental to power variances and shortfalls than subs and therefore power matching and quality are more impotant considerations when dealing with mids and highs than with subs.

Your best set up is one channel per speaker or speaker groupings based upon impeadance, power handling, frequency bandwith, size, etc. if you bridge the amp you will lower impedance handling an increase distortion as well as heat generation. Ideally you would go with 5 channels if you want separate gain control front to back and a mono channel for subs. Having your front speakers on a separate set of channels than the rears is more important if speakers are different sizes such as 4s up front and 6x9s in back as the 4s would max out before the 6x9 at same power thus the need for gain control to balance system. A note worth mentioning is that as you split your signal with ys you drop your preout voltage and lower your dynamic headroom. If you go with a 5 channel amp the only drawback is that all 5 channels share the same power supply vs a dedicated sub amp with its own power supply. other than that they are essentially just that a 4 channel and mono in one heatsink.

One thing to consider when looking at speaker power handling is that wattage is only a voice coil thermal rating and says nothing of its mechanical durability, efficiency, or sound quality. power does not kill speakers, distortion does,

I have 25+ professional experience in the auto sound and car crafting fields. You can check out my latest grand-masterpiece I am working on with my stepson here http://www.rc10talk.com/viewtopic.php?f=39&t=38800

I will try to answer questions best I can and try to explain my reasoning.

[RC104ever]

Wow that Jeep setup is insanity

[Kyoshojoe]

Ya it nearly drove me insane building it and finishing by deadline. It took about 150 hours spanning a three and half week period many days only getting 3hr naps before work and the final stint that lasted over 48hrs and I slept on the road to West Virgina University from Florida while my wife drove.

I wanted to ask the OP what his car is so I can get a better idea of what the system architecture would be constrained to. There are so many options and different ways to construct a system, and all are correct, that its best to put a lot of thought into ultimately how you want it to function. You have a good start and pioneer makes some good quality components. A couple more things to consider are possibly using an EQ to split your signal and boost line output voltage. Be careful though as EQs are notorious for engine noise if you have a bad charging system or bad grounds. When it comes to running a sub off of the pioneer amp its not really designed for it. A digital monoblock amp is your best bet.

Another thing I was about to buy some new Pioneer speakers but decided to hold off as I wasn't happy with the tinny sound on the sound board. I was pretty set on a couple of them due to their extremely high ratings from many different reviews, but was dissapointed.

It might be a case of the Kenwoods are more efficient and have a lower power handling which in effect equates to a lighter more nimble motor and piston structure, sounds great at low power but will max out quickly and ultimately only get so loud, the pioneer will need more power to reach the same volume as the kenwood and the kenwood will soud louder and clearer at same power levels but ultimately the pioneers will go louder and be clearer at higher volume levels with adequate power.

[RC10th]

Thanks everyone for the input, it is all really helpful.

I've read about powering the front is better since that's where you want the sound. In my case my front speakers are tiny and there isn't much room to go bigger (speakers are behind the kick panel) being such a small speaker I think powering from the head is fine. I'd rather speakers that carry more weight (unless someone says otherwise) I don't like high notes as they hurt my ears and rarely crank the stereo, unless I'm outside within close proximity to the car, or a killer song comes on.

Being so small is this a case of buying the best quality speakers you can afford?

I'm not out to build a big system, vibrate windows or annoy the cars next to me, just to improve sound quality. The system I had in the US was reasonable and the thing that amazed me the most wasn't the big banging power, but at the "background music" sound level, it was amazingly clear and full.

Car is a 4 door 70's fairlane so it's big and spacious but lacks speakers. About splits etc you can set gain etc on both A and B channels, not sure about the filters as I'll have to double check.

[jwscab]

i still stand by my initial recommendation. wire the fronts to the head unit amps, pre-amp rca jacks to rear amp. A channel to your deck speakers and B channel low pass to sub.

if you ever upgrade your front speakers you can revisit how much power you need to feed to them.

volume and sound pressure level are one and the same until you reach distortion, at least that can be controlled by the user. measured in dB. At some point you saturate the voice coil, and at that point, volume and sound pressure decouple because the cone can't keep up=distortion.

while a good front speaker will sound great powered by the amps, I'm betting the factory cones are gonna crap out just using the head unit power amp. wired any other way will distort the front speakers before anything else.

[RC10th]

I think the front speakers are already Alpines but I plan to replace them hopefully soon with something better, same with the rears. If the fronts are only little 4" speakers I feel no matter what they'll only take so much.

I guess sound quality and clarity over performance would be my goal.