Dizturbed One

I was running Xplod stuff that I'd gotten a couple years back, and I finally wanted to put something decent in the car, so I picked up a used JL Audio 10" W3v2 with the amp included. Hooked up to my Xplod amp (it put out about 150 rms to the sub) it sounded pretty good. Well I got rid of that and hooked it up to the alpine that came with the sub.

The guy that had it hooked up before had it knockin LOUDLY and very clean in his caprice, but it seems to perform about as well as my old Xplod in the camaro. I attribute it to the loss of power with the alpine amp.

Then my buddy told me the guy that had it before had ran 2 of each 4 channels bridged, then hooked both of those bridged channels to the sub.

This sounds odd as hell to me, and seems like I'd blow something, so I wanted to consult with you guys first.

Is this okay to do?

Dizturbed One

i know this cant be alright to do, so i'm not even going to attempt it... but im hoping you guys have some other ideas as to how he got these speakers sounding so much better

Gummie

What you're describing (combining channels to drive a single load) is called bridging and is a commonly practiced thing in the audio world. It won’t hurt the amp assuming you don’t exceed its maximum rated load. Most 4 channel amps are stable at either 2 or 4 ohm x 4 and 4 ohm x 2 (ie the amp can handle two 4 ohm loads, four 2 ohm loads, or four 4 ohm loads). Assuming the coils on your sub are 4 ohm you should be ok running it like this. If you gave us the specs on the sub and amp (model #s, coil resistance, etc) I could give you a defiant yes or no.

You should also reset the gain on your amp if you haven’t done so already because you most likely have a different preout voltage than whatever that guy had.

Finally, what kind of box was he running and what kind of box are you running? This will make a difference as well.

Dizturbed One

sorry, i left out alot of stuff and wasn't too clear.

my amp is rated for 2 and 4 ohm loads, there are 4 channels. channels 1 and 2 bridge, channels 3 and 4 bridge, giving me two bridged channels. 4x40 watts at 4 ohms and 4x50 watts at 2 ohms. the sub is a 2 ohm dual voice coil.

he gave me the same box he had in his car with the sub, a nice and stout 3/4 inch MDF sealed box with padding glued to the insides nicely. as a matter of fact he rolled up knockin it cleanly, turned it off, pulled it right out and handed it over. so i'm running the same setup he is.

i already have channels 3 and 4 bridged and I'm running the sub off of that with the gain all the way up. it definitely sounds better and hits harder than my old sub, but my old xplod 500 watt 4/3 channel amp pushed this JL 10" alot closer to what this guy sounded like, but still not as hard. and he did it with THIS amp, the one i have now. the setup sounds clean, but it distorts before it knocks like it did in his car. it sounds underpowered.

after i said something about this a mutual friend told me the guy i bought it from had BOTH bridged channels (all four channels) running to the sub with two lengths of speakerwire. i was very skeptical but he swore up and down it can be done. the only problem is he's known to just spout off at the mouth for no reason once in a while.

Gummie

From what your friend said it sounds like he was running two channels per coil. To do this hook one coil up to the + on channel 1 and the - on channel 2. Do the same for the other coil on channels 3/4. Check your amp's manual to be sure that it can run at 2 ohms x 2.

Dizturbed One

i dont think the amp can run at 2 ohms bridged

could i wire my voice coils to run the sub at 4 ohms and do this?

Gummie

I doubt it's supposed to be able to as well but that's not to say it can't. I know I was running my old amp well below it's max rated rated load. It worked, I had no issues, but it's never recommended to do so. That's not to say that the guy you bought the stuff off wasn't doing that, which probably explains the difference in output.

You can bridge two of the channels on the amp for the 4 ohm load but very few four channels can be bridged down to one channel.

Dizturbed One

I don't think its possible that he was running it like that.

he didn't open the sub and unhook any wiring or anything. he simply unhooked it and handed it over.

i really wish i could figure it out... but its ok, i think i'm going to try and find another 4/3/2 channel amplifier that will put out more wattage. that way i can run my 6x9's in the rear and the one 10" JL bridged for now. then i can buy a matching woofer and run both JL's off of that nicer amp and use this alpine for the cab speakers.

recommendations on a nice 4/3/2 channel amp that will RMS 300 watts per bridged channel?

Gummie

This is really the only reasonably priced thing I can think of: JBL GTO 75.4. 104 x 4 and 284 x 2 for $175.

You're really better off buying whatever you really want now though. Get a good sub amp and get a good two/four channel amp for the rest of your speakers. It will save you money in the long run, believe me. You're going to want more than 600 watts total for both subs so you might as well just buy a monoblock and save the alpine for your main speakers.

Dizturbed One

600 watts of sub power will be fine for me. I'll ditch this Alpine altogether, it looks like it's had a long life. I just got it because I knew it sounded good with the sub and it was dirt cheap. I'll just grab something like that JBL amp and use it for my 6x9's and this 10". I'm not too worried about my soundstage. I just want a reasonably good clean sound that will knock at a decently high volume without distortion anywhere.

I'm not trying to compete, all of my friends run competition or near competition setups, so it's no use for me unless I'm going to get into it like I'd really want to, which I can't afford.

I've just always been an audiophile, and music is damn near my whole life, so I have to have SOMETHING decent.