Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th December 2001, 08:38 AM   #1
diyAudio Member
 
Join Date: Dec 2001
Question Wiring two amps together???

Hello all -

I have a sub in the back of my car and was just given two identical amps.

Is there anyway to connect the two amps together to make one higher output amp? I think the answer is no, since it really doesn't make any sense, but maybe someone has done it ....

-David
  Reply With Quote
Old 12th December 2001, 11:49 AM   #2
Warp Engineer
On Holiday
 
AudioFreak's Avatar
 
Join Date: Oct 2001
Location: Queensland, Australia
Yeah its called bridging. You connect the positive output of one amp (call it amp number 1) to the positive input of the speaker and the positive output of the other amp (call it amp number 2) to the negative input of the speaker and you leave the ground terminals on both the amps unconnectted ... you then feed amp number 1 directly and you invert the same signal and feed this inverted signal to amp number 2.

This will have the effect of allowing each amp to drive half the actual load so each amp produces twice the power that it normally would. Therefore, the speaker will now see 4 times power of a single amp.

Just a warning, make sure the amps are capable of driving half the load of the speaker. ie. if it is a 4ohm sub make sure the amps can drive 2ohms each or the outputs of the amps may die.
  Reply With Quote
Old 12th December 2001, 03:11 PM   #3
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Two more points:
--The amps should be identical (you don't say whether they're the same or not).
--Some output topologoes don't like being bridged.

Grey
  Reply With Quote
Old 12th December 2001, 03:33 PM   #4
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
Basically, the grounds of the two amps have to be the same, and therefore by implication have to be tied to vehicle battery ground. Check with an ohmmeter whether the speaker ground on the amp is the same as power ground.
p.s. Grey, he did say they were identical...
  Reply With Quote
Old 12th December 2001, 05:45 PM   #5
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
Snooore...
Huh? Wha?
Oh, yeah, identical...right...
G'night

Grey
  Reply With Quote
Old 13th December 2001, 04:40 AM   #6
diyAudio Member
 
Join Date: Dec 2001
I should have given you guys more specfics (not to downplay anything you have said, just for my own benefit).

I have two, identical, bridgeable, two channel amps that are stable at 1 ohm. So I have two pairs of speaker outputs per amp. Which positive speaker output do I connect to the sub? Also, I have one dual voice coil sub (4 ohms per coil). Isn't what you are saying the exact same thing as connecting one amp to each coil? Isn't that a bad thing to do since any variation in the amps/signal will cause the voice coils to fight eachother instead of cooperate? Would your suggestion work perfectly for a single voice coil sub? It seems like it would, so it should also work perfectly for a dual voice coil sub if I have the coils wired in parallel or series (mine are in parallel for a 2 ohms load).

When you say invert, does that mean just take the preamp RCA connection from my head unit, split it with a Y, connect a pair correctly to amp 1, and flip the connections on the other pair to amp 2? I didn't think that would make a difference since I only have one sub so it's mono, but it seems like that would change the phase 180 degrees. If I connect one amp per coil, will I also have to invert the signal on one of the amps?

Why do you have to invert the signal anyway?

What are "topologoes"

Thanks
David

  Reply With Quote
Old 13th December 2001, 12:39 PM   #7
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
Quote:
Originally posted by dih1118
I have two, identical, bridgeable, two channel amps that are stable at 1 ohm. So I have two pairs of speaker outputs per amp. Which positive speaker output do I connect to the sub? Also, I have one dual voice coil sub (4 ohms per coil). Isn't what you are saying the exact same thing as connecting one amp to each coil?
...
Why do you have to invert the signal anyway?
...
What are "topologoes"
My goodness.
If your amps are already bridgeable, they have an inverter built in somewhere. The inverter changes the polarity of one of the signals so that the speaker can be driven from two outputs - one output will be exactly opposite the other (in a non-bridged setup, one side of the speaker will be fixed at 0). You get twice the voltage, see. You use the two channel's positive outputs, one to each side of the sub's voice coil.
Because your sub has two coils, and each amp is bridgeable, you can use both channels (each amp bridged to make effectively one channel) of both amps to drive the sub. If you feed both amps with the same signal, the signals won't be 'fighting' one another.
I don't know about topologoes, but by topology Grey was referring to the circuit used in the amp. With some circuits, you can't bridge two channels (for example, circuits that already inherently use bridging).
The manuals that came with the amp and sub should explain this as well. I strongly suggest you read them carefully before starting to wire this up.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
need help connecting pro amp to pc joka22 Solid State 23 6th July 2007 12:43 AM
pro amplifiers vs. home audio amplifiers bonsai171 Solid State 26 25th February 2004 08:24 PM
Paradigm amplifiers? Anthem amplifiers? Corn-Picker Solid State 2 24th January 2004 03:10 AM
connecting car amplifiers Aaron Everything Else 0 17th June 2003 01:35 AM
Many smaller amplifiers vs. bigger amplifiers. djdan Solid State 9 17th September 2002 04:40 PM


New To Site? Need Help?

All times are GMT. The time now is 07:47 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2