Got this in three years ago:

HU: Alpine CDA 7873R
Front: Blaupunkt Overdrive components (650 or 660 i think = 70w or 80w rms)
Rear: Alpine SPR 692A (50w rms)

The time has come for bass. I was thinking of a 10" boxed sub with a 4ch amp running it and the front splits. I was planning to put the amp in the boot and have the sub box easily removable for when I need the whole boot.

My CD box at present has AC/DC, John Butler, Powderfinger, INXS, Moby, Eric Clapton, Dire Staits.

I've also noted, as I get older, that the volume knob gets turned down lower and lower. Then you realise that there is no bass at all at low volume. ie I'm not looking for SPL, just to improve the sound quality at lower volumes. I have to turn the rears up at present to get some bass so the sound staging is crap (over my left ear).

Q1: Am I going down the right track with sub size for my needs?

Q2: One sub vs Two subs (same size) in terms of sound quality?

Q3: Who wants to venture an opinion on an amp and woofer if I'm looking $2000 all up including wiring and bits.

Q4: How simple would it be to hook up a couple of switches and some extra wiring so the amp can run the 6x9's when the sub is out.

I used to know the answers to all of the above but I havn't touched a piece of MDF or a jigsaw for about ten years.

From jaycar.
10" sealed or ported box 25 litre = $39.50
12" " " 35 litre = $50
5 metre RCA leads ~= $20 each for reasonable quality. x 3(sub/front/rear) = $60
Good speaker wire, 2-8 gauge wire for power to the boot = $50
Fuses/connectors = $30
I'd budget a fair bit on your amp to give you a lot of headroom and/or options to upgrade your fronts/subs later on.
Amp ~= $800
Good amps:
Phoenix Gold
Audison
Zapco
Alpine V12's
JL audio
Phass
Boston

Sub = ~= $500
Hertz
Phoenix Gold
JL audio
heaps more...

It's pretty hard to recommend subs and amps... I can shout out brand names all day long but you have to get out there and hear the things for yourself... Check out some stores, or preferably find someone nearby who has a good setup. Let you ears decide though.

It also comes down to what you have access to locally, or if you want to buy interstate etc. check out www.caraudioaustralia.com in the forums - for sale section. You can pick up good 2nd hand amps there for $200 - +2000 but there is usually stuff going for pretty cheap and I've never had a problem with anything I've bought there.

How much handy man work can you do? Installing the whole lot includes, re wiring the front speakers, and running wires through to the back of the car, under the carpet, as well as 2-3 sets of rca leads to provide a signal for subs and a signal for front (or rears). I take it your head unit has sub woofer out? Otherwise you can use the crossovers on your amps without too much drama.
You'll need something to mount your amp on, if you want it to be discreet a false wall is generally the go, that's just made out of MDF. and can be put anywhere where its not in the way.
Wiring up the car the hardest bit is getting through the firewall. Just find a big grommet in there somwhere and poke your wire through it. Connect that up to the battery... (make sure it's fused appropriately (very close to the battery ~ two hands length Maximum. Fuse siz should be the total of whatever fuse(s) is(are) in the amp. (probably 40a-50a)
You'll need to make a good ground point in the boot, sand back the body to metal and put a screw through with a star washer to 'eat' into the wire. The grounding should be short and the same size as the power wire.
Installing the sub is pretty easy. Either make or buy the box. (they're not that expensive and screw the sub in. If you're after good sound quality, there will be specs on the amp about the correct volume box for the sub and the correct way to tune it. tune it to 30hz but if all thats too complicated you wont have to worry. You can fill up a boxes volume using material eg dacron filling.

Your sub will be easy to take in and out, You might want to make some clips or brackets to hold it in place so it doesnt bump around when you're driving...
You probably won't need to amp your rears at all, but it wouldnt be too hard to rig something up. Might be a bit of hassle changing all your amplifier setting moving from sub to speaker. Maybe you would be better off running all speakers through the 4 channel and buying a Monoblock(class d amplifier)~=$500 to run the sub(s). Which is an amplifier designed to play lower frequencies. And which is much more efficient compared to a class a amplifier (like your 4-channel will be )maybe theres some upgrade options for later anyway.

1 or 2 subs??? I'm running two 10's in a sealed box. If your after good sq i recommend a sealed box with the correct volume for the subs. But if you want it to get down low I'd go a ported. Sealed boxes have a bit more punch and can handle more power. But spending twice as much on say a good 12" would take up less space and you could get yourself a really high sq sub which you may well be happier with.

Erm that's all for the moment, I'm off to Stakes Day :) To lose some money...

Hope it helps

peace

Tim

hey mate i got a good 4 channel amp for sale if you're interested, Eclipse EA-3422 50wx4. couple months old, still under warranty, box, receipt. pm for details. :)

eclipse are relatively new but they are a very good manufacturer, especially subs!

Cheers for the comprehensive answer Tim.
MagnaBishi - I'm gonna buy new but thanks anyway.

I have a few amps in mind now and I need to have a listen to some subs.

I do have two more questions.

1. I have decided on one 10" sub (sealed enclosure but not ported) running off two channels of a 4ch amp. Does that mean it has to be dual coil?

I plan to put the box right in at the back of the boot against the seat. Less then 12" front to back. My two options are to have the sub facing out to the rear and have the amp mounted beside it or behind it (so you can see it through the ski hatch) or face the sub through the ski hatch and mount the amp on the other side of the box (so you can see it when you open the boot).

2. Anybody done the sub through the ski hatch thing and am I barking up the wrong tree for sound quality?

my bro is an installer, and he has done his own test in 3rd gen magnas and says the best postion in the boot to place the sub box is 55mm from the back of the boot facing the rear. now i know that this is not the most convinient of places and u have to secure it there, but it does make a huge difference in sub noise, has to do with the wavelenght of the sub frequencies and distance travelled off the back of the boot to the front

I could kiss you s_tim_ulate!

Off 2 jaycar I go!

:redface: Ah no worries guys...
I agree with facing the subs backwards I have generally found better bass response by facing the subs toward the rear of the car. There probably is a better reason for this but some have sed the bass bounces off the back I also beleive you get a good effect from the acoustics in the boot itself. Supiria sounds on the money with this.
If you want to face it forward, it is pretty important to properly seal it off from the boot otherwise your bass will sound dead... And when you open up your boot it will surprisingly sound louder, go figure.
To seal it off from the boot you usually need to make a custom enclosure etc... and this has to completely seal off the backseat for the boot. Bit of hassle really.

Sit them behind the seat facing backwards or sit them in seperate boxes just behind the taillights facing the ski port if you have 2 subs.

There are a lot of options with subs/amp wiring combos. You may want to invest in a way that allows you to put in another 10" sub later on. I'd go with a monoblock. One that is stable at 2 ohms preferably 1 ohm too. if its 1ohm stable you can get a dual 2 ohm sub. And wire it up in parallel so the amp sees a 1 ohm load. Alternatively you can wire this up in series so it sees a 4 ohm load.
It's not a good idea to run a sub off two channels. As the channels will not be providing the exact same signal, due to imperfections in the amp etc. You always want to run off one channel (monoblock).
Find out what amp or what sub you want to get first then work from there. Make sure your amp can power your sub though. Don't load down amps when they arent designed to otherwise they will constantly overheat and go into protection.

Have you had a chance to check out any subs yet? Do u have an idea of how much power you want? Will you eventually want to upgrade to 2 subs?

Peace

Tim

Hmmm $2000.....
Amps:
Zapco Reference350.2 and Reference500.1 or Phoenix Gold R4.0:2 and R8.0:1:
you should really amp your front stage dude. E-mail FRHX for the deals he has going at the moment on 2ch + monoblock combos.
Sub:
Boston G2
Vibe Blackair
Hertz HX
JLw0

Add sound deadening to that bill as well if you want good sound. Fire the sub toward the back as it sets up a better sine wave which means it is louder and is more accurate. If i was you and had $2000, I would go for a simple upgrade like new splits, old splits in the rear, 3 or 4 channel amp, Audison SRx3 will do nicely and a nice sounding 4 ohm sub. No need to go overboard as you are after quality that doesnt really need to be able to be turned into a 150db sterio later.

Thanks for the advice guys.

I've settled on an Image Dynamics IDQ10v2 10" sub (~$400) but still have 4 amps on the short list:

Zapco 360 ~$995
Audison LRx 4.300 ~$875
Tru Tech T4.65 ~$860
Audison SRx3 ~$697


I can't decide which one to get. I have a hunch for the Zapco but also like the others for various reasons.

Any opinions?

mmm the tru tech is nice. All are roughy equal on power performance with it ranging from 50WRMS - 75WRMSx 2 and 180WRMS - 250WRMSx 1. If you got the SRx3 you could get new splits but if you like the sound of your splits then definately go for one of other 3. :D

I'm going to close this one up.

For packaging reasons I've settled on the Zapco (it fits on top of the sub box quite nicely).

It will be a few weeks 'till I get all the parts together, build the box, wire up the car and tune the system. Will let you know how it goes.

Cheers.