how to bridge an amp

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

Hello people,

i have subwoofer that are 600 peak power and a 2 channel amp that is 250 each channel.i just want to know how to bridge two channel on the amp so i can pump out the max power of the amp to the subwoofer? and is it hard?

Post by **Silvia007** » Wed Sep 04, 2002 4:10 pm

Easy... this is what you do, make sure your amp is set to mono, if not, oh well. When that's done, connect the negative speaker wire to the negative terminal of the right (Channel two) channel hookup on the amp and connect the positive speaker wire to the positive terminal of the left (Channel one) channel hookup on the amp, that should be it. If you these instructions aren't clear, I'll try again. Hope this helps.

Post by **dcmetro240** » Wed Sep 04, 2002 4:10 pm

Silvia007, is somewhat right. Most amps bridge that way but depending on the brand of amp you have it may be different. I have seen some that bridge neg to neg and some pos to pos. so if neg to pos doesn't work maybe one of the other ways might.

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

is a jensen brand, that i got off from ebay..

ok let's say it is neg. to neg. , pos to pos. then where is the subwoofer wire gonna connected to when all the terminal of the channel are used? am i suppose to flare the subz wire to the both channel?( i think that's the word for it-when u put it on a junction)

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

Whoa... slow down boy!!! I can't make heads or tales out of that last post. First of all NOT ALL AMPS CAN BE BRIDGED SAFELY!!! You said something about using up all of th eterminals on the amp... how? If you bridge an amp, you go from 2 channels down to 1. It sounds like you might have the wrong idea of how this works. If you have a 2 channel amp, and a single sub, or duals wired in a series with 1 terminal, then you can bridge the amp. But if you have two subs wired seperately, you don't bridge the amp.. leave it as is. Also, it is called a splice when you "combine" or connect two wires, or split one wire into two. Post exactly what you are working with and maybe we can actually help you:

1. How many speakers are in your sub-enclosure? (you used plural and singular forms in your description.. your verb/noun agreement left me confused)

2. How many terminals are on your sub-enclosure? (how many + and - holes are there)

Post by **InstantRice** » Wed Sep 04, 2002 4:10 pm

Christ that last post was confusing, not yours maine. like he said post the equipment and specs ie. amp, subs, voice coils/ terminals. and explained what you mean by flaring sub wiring. ive never heard of this term but im not saying its wrong. also it looks like you are matching your amp to subs by looking at peak power. look at rms.

Post by **johnsharpe** » Wed Sep 04, 2002 4:10 pm

I agree, let us know what junk is in the trunk, and then we can provide better info...

However, from my professional audio days, so long as the amp is designed for the load that you will present to it, most 2ch power amps can be bridged by the following method:

<Disclaimer>Do this at your own risk...I assume absolutely zero liability or responsibility for you letting the smoke out of your amp or toasting your speakers!></Disclaimer>

Inputs:- split the incoming audio signal (line level from deck) into 2 (simple splitter)- phase reverse one of the signals- in-phase plugs into ch1 input , out-of-phase in ch2 input

Outputs:- spkr +'ve plugs into ch1 +'ve- spkr -'ve plugs into ch2 +'ve

Keep the gains for both channels the same, otherwise one side of the sinewave will be at a different amplitude that the other...not good for the gear or the ear.

Did I get that right?....it's been a while.Cheers,John

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

haha sorry about the language guys, i type even worse on aim.

ok, i ordered an amp from ebay that have 2 channel, so that means it have 2 ( - ) and 2 ( + ) right? 250 each channel.

i have 1 basstube that can handle 600 peak power, is the one from Bazooka that looks like a nos tank. LOL

ok i want to bridge the 2 channel together so i'll get max power from the amp to the sub. If i put neg. to neg. and pos. to pos.(as mentioned eariler) then where does the basstube wires will be connected to? Is there other insert for the basstube wire, because I thought that the basstube wire is suppose to be connected to one of the ( - ) and ( + ).

What i'm trying to say eariler is that if there are no other insert(plug-hole) for the basstube beside the terminals, and if i bridged them then where does the basstube wire goes?

i tried my best to make it clear~

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

Ok.. so it's a bass tube.. I haven't heard that word in about 10 years.... don't get me wrong, I used to own one too, until band-pass boxes came about, then I realized they both pretty much suck... open-air enclosures with real subs are the BEST!!! But a Bass tube isn't bad, it'll do!

How many "bass-tube wires" are there? It sounds to me like the bass-tube might already be amplified internally... many of them are. If it has an onboard amp, it will have 2 or 4 speaker wires, a power source wire, and a ground wire. If it isn't it will have either 2 or 4 speaker wires only. If it has JUST 2 speaker wires, then and only then do you bridge the amp! Connect it as was described earlier. If it has 4 speaker wires.. wire them normally, it is the BEST way to do it.. If it has 2 or 4 speaker wires and power and ground wires, DON"T USE THE AMP!!!

Post by **InstantRice** » Wed Sep 04, 2002 4:10 pm

on the grounds you have the nos tube i refuse to help.:thumbd

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

I've never seen a bass tube styled like a N2O bottle, is that for real, I thought it was a joke..... OMFG! Anyway, I won't be mean, are they amplified already or do you need an external amp... I've never seen one so I'm not sure how they are designed...

Post by **MasterMan** » Wed Sep 04, 2002 4:10 pm

damn-didly... OK when u get your amp just look at the owners book it will show u how to bridge the amp.. if it doesnt sometimes its even on the amp itself.. some amps u have to buy a thing to brige it.. but most all of the new ones have it built in.. and by the way.. THE best system is a closed box.. period.

Post by **InstantRice** » Wed Sep 04, 2002 4:10 pm

why yes the n20 tube is a reality and a scary one at that. sub amps that arent mono blow goats ne way.:pface

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

MasterMan wrote:.. THE best system is a closed box.. period.

We'll have to agree to disagree! :rolleyes

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

ok guys, i don't know if the bass tube is already internally ampflied or not but here is the spec for it. If you guys want to see the picture of it or something, go to ebay.com and type in bass tube it should show up.

Key Features:

8" woofer frequency response 39-1,500 Hz handles 300 watts RMS 600 watts peak power sensitivity 102 dB 4-ohm impedance 8-1/2"W x 27-1/2"L x 10-1/4"H

The amp i'm getting is from ebay so i don't know if it'll come wif an instruction booklet or not. And here are the specs for the amp-500 Watts Peak Power! (both channels combined)

250 Watts RMS 2-Channel AmplifierNumber of Channels: 2Peak Power Per Channel @ 4 ohm: 250 wattsRMS Power Per Channel @ 4 ohm: 125 wattsPeak Power Per Channel @ 2 ohm: 330 wattsRMS Power Per Channel @ 2 ohm: 165 wattsBridged configuration (1 amplifier per channel) Peak Power @ 4 ohm: 600 wattsBridged configuration (1 amplifier per channel) RMS Power @ 4 ohm: 300 wattsMOSFET power supply Parallel MOSFET output transistors 2 Ohm stable (stereo operation) Tri-mode operation Bridgeable operation Variable high-pass crossover (50-250Hz) Variable low pass crossover (50-250Hz) 12dB Variable bass boost @ 45HzHigh level inputs Input level control(s) Optically isolated ground Paths Clear-coated PCB for extra moisture protection Die-cast aluminum heatsink Die-cast aluminum endcaps Side mounted controls Thermal/short circuit protection Power LED indicator Protect LED indicator

By the way i'm still a bit confuse of how to bridge it or should i say even doing this.

Post by **QUICKFLOW240** » Wed Sep 04, 2002 4:10 pm

ok it's simple

First off you will haveonly two wires from the sub. take the positve wire from the sub and connect it to the positive terminal on the left channel of the amp. Then take the negative wire and connect it to the negative terminal on the right channel of the amp

Post by **89sxRCR** » Wed Sep 04, 2002 4:10 pm

If you dont know how to bridge than do you even know how to install? If you dont know find a friend who does and just watch and learn. Also your gonna wanto keep those amps down going to that 8" sub, 300 rms is what you should be keeping it around. Overpowering that will fry it (iv fried my share of subs) And 8" subs werent really meant to bump, if you want that try 10s or 12s. 8 is for sound quality inside the car, so bridging it and then cranking it up so it eats up the 500 watts might be pointless.

this has been my humblest opinion

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

89sxRCR has a good point, if you don't know how to install, have a buddy there with you who does.. the best ways to learn are to watch someone else do it, or do it yourself and learn from your mistakes! Also, 600w peak power sounds a little crazy.. you're gonna toast that sub in no time. Not sure what kind of quality sub you're getting in an N2O bottle, but with that kind of juice running through it, I can't imagine the sound reproduction quality will be any good. A smaller amp will much better serve your needs, this one is going to ruin your sub if you push it.

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

coolioz, thanks guys.

i was going to call one of my friend and help me install it because he know these audio stuff. I"m just asking cause i just want to know in advance.

1 more question, If u connect the 500watt amp to the 600sub does it push out all 500? or would there be like a volume-like botton that you can put in more if you want and put in less?

Post by **QUICKFLOW240** » Wed Sep 04, 2002 4:10 pm

Just another 240 wrote:
1 more question, If u connect the 500watt amp to the 600sub does it push out all 500? or would there be like a volume-like botton that you can put in more if you want and put in less?

Ok I don't speek giberish but from what I gathered you are asking if there is a power controll on the amp which regulates the amp's output level. Yes it's called a gaine controll. It is built into the amp and is the basic feature that keeps you from blowing your speekers.This will need to be adjusted acording to the speakers RMS not PEAK from there you can tune it to your tast.

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

aite cool.

what's rms now? lolz

Post by **InstantRice** » Wed Sep 04, 2002 4:10 pm

rms is the average amount of power that a speaker can take and will take w/o cooking. The peak is the maximum amount of power that the speaker takes in short bursts(usually listed power is not the maximum). if you want a more complicated answer just ask.

Post by **89sxRCR** » Wed Sep 04, 2002 4:10 pm

dont worry about plugging ALL the potential watts into the sub, even if you just give it the single channel 250 it would be perfectly fine and clean sounding. You want to dump in 500? get a bigger sub.

So you might want to get a less powerfull amp to save money

Post by **InstantRice** » Wed Sep 04, 2002 4:10 pm

or you can do want most people do and turn down the gain. you can throw tons of power at a good woofer you just need to turn the gain down. but i might be taking him a little to fast.

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

89sxRCR wrote:, even if you just give it the single channel 250 it would be perfectly fine and clean sounding.

Yeah.. you'll just be missing the signal from whatever side of the STEREO you're not hooked up to. If you don't mind pumping the bass from one side, and nothing from the other you're all set. The only real good result of bridging it is to capture left and right channels, and send them out as one channel to the sub. But then again, that's only if the amp has a mono selection... and then it would have both left and right anyway... never mind.... I forgot what my point was................. uuuuuuuuggghhhhhhh! long day.

Post by **89sxRCR** » Wed Sep 04, 2002 4:10 pm

ur right hed only be getting one side but its bass, so who cares, its usually the same thang. When he "bumps" that 8 it may be from one side but your not going to be able to tell i dont think. I could be wrong, mines bridged.

Better than getting fried...and im assuming you have it on low frequencies only, so its not just another speaker.

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

It really is just another speaker, and it will only reproduce the signal it receives. If you don't mind getting the bass signal from one side only... then do it up! But the point of stereo sound it the fact that it is divided left and right. A LOT of music will have all kinds of lower frequencies split differently between the two.. personally I'd like to know that my sound reproduction is as close to perfect as I can get it....

For example... picture a scenario where the drum tracks are split pretty evenly 50/50 left and right, so the left speaker would pick up the "all important" bass drum beat...... But the bass guitar is split 75% right and 25% left.... in the studio it was engineered to be sonically correct to the artists and engineers personal tastes. Now that your only going to amplify the left side... you've got 100% of the intended bass drum volume, and only 25% of the intended bass guitar volume. Now your sound reproduction is flawed. This is just a hypothetical scenario.. but it DOES happen this way with ALL different kinds of recorded music.. it is the very nature of STEREO sound....

Post by **Just another 240** » Wed Sep 04, 2002 4:10 pm

RighT guyS! ( i got 1/2 of the stuff ya talking about. lol)

so anyways, it is best to bridge it and try to get the left and right side sound right?

Post by **89sxRCR** » Wed Sep 04, 2002 4:10 pm

right you want the left sound right left. right? cuz if the left sound were coming from the right it wouldnt be right it would be left.

Post by **MaineExport** » Wed Sep 04, 2002 4:10 pm

I think I left the right answer in my left pocket.. yup it was right there the whole time. Bridge the amp because it is important to have ALL of the audio signal available. The amp will have a crossover to cut out high end. Running it bridged will deliver more power to the sub... but that's not the important part.

For your aplication, a bridged-mono amp is what you want to push your single sub........ OK :rolleyes

how to bridge an amp

how to bridge an amp

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