A Few, hopefully intelligent, Questions

[Immortal 10+ year member]

Hi, I've recently begun researching car audio systems and how to choose/build a correct set up, but the net is full of conflicting info and somewhat lacks beginning- to-end tutorials. Hopefully you can answer a few my questions. I'm actually going to a car audio trade show tommorow so ill certainly talk to them and see what they have to say, and supposedly find some good deals (we'll see lol), but I'd like to ask some general questions here first.

Alright, I am trying set up a system in my 2004 Ford Escape composed of:

- 4 speakers in the stock positions in the doors, probably 3 way if I find a good pair that fits but 2-way isn't out of the running. I'm looking for higher RMS, which will lead to a question in a second. All will have crossovers built in to make them better.

Here is a good example of a 100w RMS 2-way

I was looking at, just a quick BestBuy search:

http://www.bestbuy.com/site/olspage.jsp?skuId=8222336&productCategoryId=abcat0302008&type=product&tab=1&id=1166840026861#productdetail

-Dual sub enclosure in the back, the more powerful the better, not trying to go crazy with price. Yes I know about Ebay and hopefully this car show. If all else fails I found a well reviewed and powerful yet cheap system on best buy.

-Amp to power it all, of course.

Hence my questions:

Ok, please fell free to fill in anything in missing or am not understanding.

Im told to power all of this, I would want a 2 channel AMP pushing LESS power to each sub in the back then their RMS value. So I would want an amp that pushes 300 RMS to each 400 RMS sub, for example? I'm told I want to underpower the amp to the sub rather than overpower it or match it. Like find an amp the top 1/3 of the sub RMS value. Is this right?

Part 2 of this question is, how do the 4 speakers come into play? Do they also draw 400 watts off the amp since they are each 100 watts? Does that matter (can I stay at a 300 watt Amp) or do I need to somehow add that in to the amp power, and if I do, wont my amp max go over the sub? Maybe I am supposed to do something with the wiring to direct the current to limit it (just a guess)??

Does cd player/dashboard deck = head unit? and how does that play into the power requirements? Is deck RMS relevant when I have a seperate amp? I guess it supplies power to the speakers so im guessing the amp takes over that. Do I need to compensate with speaker level inputs that account for deck amp signals? And if so, do most decks come with that?

I guess while I have your attention ill finish off with these. Do most premade dual sub enclosures sold online list the RMS of the total system (my assumption) or each sub? Example:

http://www.bestbuy.com/site/olspage.jsp?skuId=8359616&type=product&id=1177112903683

What is the deal with ohms and impedance? I think the whole system will use 4 ohms but im not sure what this is all about.

Also, with the sub, do I want a dual coil or single coil and how can I tell which a sub is, using the one I just linked to as an example?

Thank you for your time in advance, if I get more questions ill be sure to reply...

Love you all //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[nauc 10+ year member]

for best sound quality (sq) run a set of 2 way components up front, and a sub in the trunk, forget any other speakers

as far as amps, if you have a 100 watt speaker, id feed it at least 100 watts. the amp works less, the signal says undistorted youll get all you can out of your speaker

better to have more power and not need it, then to run out of power and dirty up the signal trying to get more out of the amp than it can produce, ruining the speaker

yes, deck = head unit = cd player etc

dont worry about deck power if you plan to use amps for your sub and highs

look for my 2 posts for tons of more worth while info http://www.caraudio.com/forum/showthread.php?t=238243

and forget BestBuy and all the crap theyre sayin and selling, theres way better for the $, we'll hook you up

 

[Immortal 10+ year member]

Thanks mate, ill check your posts in a sec.

So I should go for 2 way over 3 way speakers in the front, and just leave the stock two in the back?

Can you elaborate a bit more on your amp comment please?

I figured as much about the deck

 

[nauc 10+ year member]

as far as subs voice coils, since most amps put out more power the lower the impedance, which means youll get more power for your $, id look for a dual 2 ohm sub, wire it up parallel

other than that, theres not much else about svc or dvc

more info

http://mobile.jlaudio.com/support_pages.php?page_id=161

 

[Immortal 10+ year member]

Trolling is fun ^.^

the page you sent me was all DVC, im guessing that is what I should buy? How can I tell? So a better sub would be advertised as 2 ohm in the specs (rather than 4ohm in my link) because when ran in parallel/parallel it produces only .5 ohm, which means the amp is more efficient. Hope I got that all right

I know its Best Buy, I just wanted a solid example link I could learn from since they listed the stats on there. Any suggestions on what to buy for I am trying to do?

 

[nauc 10+ year member]

Thanks mate, ill check your posts in a sec.So I should go for 2 way over 3 way speakers in the front, and just leave the stock two in the back?

Can you elaborate a bit more on your amp comment please?

I figured as much about the deck

3 ways up front are a lot harder to make sound right. the more speakers in the car, the more acoustical problems can arise. you get all kinds of cancellation/reflection problems etc etc. and theres really no need, 2 ways can do the job no problem

id take out the rear speakers all together, which will let the bass from the sub vent into your cars cabin

amps just amplify the decks signal, but it can only do it so much before jackin up the signal, distorting it (clip the signal). so if you have a 100 watt speaker, id get at least a 100 watt amp that way you get everything out of the speaker that you can and the signal going to it is distortion free

if you use a 100 speaker, a 75 watt amp and try to get more out of the amp than that 75 watts, you can distort the signal so much that its like sending the speaker 2 times as much as that 75 watts (so 150 watts) which will probably ruin the speaker over time

 

[Immortal 10+ year member]

Right, so if use two 100 watt speakers up from, drop the back two, and use for example 2x300watt dual sub in the back, I would want at least a 300 watt amp to power everything? Im just trying to get a better grip on this before I go to the show tommorow

 

[nauc 10+ year member]

dvc arent any better than svc, or the other way around, just gives you more options when it comes to matching the subs impedance to the amps impedance, i guess some could say that having more options is better

you can tell if you look at the sub if its svc or dvc, the single only has one set of speaker terminals, a + and a -, the dual (dvc) have 2 sets of speaker terminals, so 2 positives and 2 negatives

 

[nauc 10+ year member]

if you have components up front, and theyre rms is 100 per side and you have a 300 watt sub, id get at least 1 100x2 amp and a 300x1 amp or look for a 4 channel amp that does say 100x2 for the fronts and channels 3 and 4 can be bridged into 4 ohms that puts out about 300-400 watts

doubt you can find a 4 channel amp that is stable at 1 ohm, so yould just wire your dual 2 ohm sub up in series to get a 4 ohm load instead of 1 ohm

cause not all amps are stable at 1 ohm and it could ruin the amp if you try and run it at 1 ohm

 

[Immortal 10+ year member]

I think id prefer to use 1 amp. but once again I cant get an answer to this question. Since it powers all 4, do I need a 800 watt amp to run 2x100 and 2x300, or a 300+ watt amp that runs the heaviest item, the subs?

 

[nauc 10+ year member]

you could get something like this

150x4

so 150 per side for your fronts, and 600x1 for your sub

http://www.cadencestore.com/ProductCart/pc/viewPrd.asp?idcategory=125&idproduct=385

set your gain correctly so you send 300 to the sub, not 600 and 100 to your fronts not 150

 

[Immortal 10+ year member]

That looks good, bump for my other questions