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memento · Sep 22, 2003, 08:47 PM

I have a pretty kickin car stereo, but I want to replace my aging passive 8" bazooka tubes. Here's my setup that's relevant to my question:

my amp drives my component speakers and my 2 subs in parallel from the same speaker terminals on the amp. Total load is 2 ohms like that. This works very well. The amp is 2 ohm stable and only has 2 sets of +/- (that is, a +/- for the left and a +/- for the right).

What I WANT is to get a single 12" or 15" sub with an appropriate box, BUT I don't want to get a new amp. Can I wire the 2 negatives of a dual voice coil sub to the right and left channel as opposed to wiring them in series to 1 channel? Same thing for the +? Or will any difference in the channels destroy the voice coil?

G4ME · Sep 23, 2003, 12:19 AM

This is assuming you have a DVC at 8 ohms a piece, Wire the each sub for an 4 ohm load, that means just taking some wire and connecting the DVC together + to + and - to - on the sub, then wire them again in parrallel, so take the + from one sub and wire it to the + from the next, same with the negative. Then connect it to one channel of the amp, most decent amps have bridged or mono options, put it on mono, and you will be seeing a 2 ohm load and you will get the most power out of the amp.

Also make sure that the subs that you get are the pretty efficient, something around 89DB/meter is decent, this means less power will result in hight SPL

Spliffdaddy · Sep 23, 2003, 01:03 AM

You may be able to run the subwoofer from a bridged connection to the stereo amplifier. A summed mono signal utilizing the outputs from both the left and right channels. Most modern amplifiers are capable of doing this. You wouldn't need a DVC subwoofer, either. I assume you already have the passive low-pass/high pass filters.

fun fact: Sony called this 'tri-mode' operation, back in the early 90's.

memento · Sep 23, 2003, 06:54 AM

oooh - spiff. you got it.

So if my 1 sub speaker is 4 ohms, then the total load is 2 ohms still?

G4ME - I'm looking at 89dB as the min. Prefer 91+.

G4ME · Sep 23, 2003, 07:15 AM

show me a decently priced 91db watt/meter, not watt/volt cause thats is going to give you an inflated number, with a decent Qts and Fs and plenty of xmax. I haven't seen to many.

memento · Sep 23, 2003, 07:23 AM

Then I must first ask what's a decent price to you?

memento · Sep 23, 2003, 09:36 AM

in any case, these are all measured at 1 meter -
Infinity Kappa Perfect 12.1: 96dB@1m $200
Infinity Kappa 120.3se: 92dB@1m $150
JBL GT120: 93dB@1m $100
JBL GT150: 95dB@1m $150
Polk GNX12: 93dB@1m $160

G4ME · Sep 23, 2003, 03:01 PM

that kappa is at 2.83v/metter, read the PFD on infinity, that will still result in some SPL, if only i could find the TS parameters of it, i am surprised at how many car sub companies don't put out full TS parameters, so one could actually fine tune a box to your environment.

BTW those arn't too bad prices

signal68 · Sep 23, 2003, 03:29 PM

I GOTS SUBS YO I LIKE TO TURN UP THE BASS ON MY RAP MUSIC! BLEAYATCH!

memento · Sep 23, 2003, 03:49 PM

I see what you mean. The Polk is listed as 93dB with 1 watt at 1 meter, when I dig into the pdf.

The prices are from Crutchfield, and they're usually not the cheapest, but I've been using them for years. The Polk is actually buy one get one free right now.

Cash - what's your point? I'm looking for high fidelity and accurate reproduction, not booming rap crap that you can hear from your house. In fact, I have a decibel meter to make sure I know exactly how loud it is.

signal68 · Sep 23, 2003, 04:02 PM

Oh. My apologies. In most cases I consider anyone who installs a sub in their car a moron....but... you seem cool.

- Ca$h

memento · Sep 23, 2003, 04:08 PM

Better. That's the kind of response I expected to see from a fellow Subaru driver!

signal68 · Sep 23, 2003, 04:16 PM

Originally posted by memento:
Better. That's the kind of response I expected to see from a fellow Subaru driver!

Heh. The factory stereo in my SVX was actually pretty good (for a factory system), but I blew one of the door speakers....thus sending me in a spiral of upgrading everything. I installed some 200 watt orion 6X9s last weekend, but it started raining so I still don't have everything installed or put back together at the moment. I have no backseat, just insulation and wiring.

Rah. Hardcore.

- Ca$h