View Full Version : impedance question, wiring three speakers to stereo amp.


C.D.
07-03-07, 05:59 PM
hi there, i would like to wire in a center speaker into my computer system, just for now.

my computer speakers are Klipsh promedia GMX- A2.1, it has 2 2-way satellites but the only resistance spec ive found on CNET seems off compared to all other sources HERE (http://shopper.cnet.com/pc-speakers/klipsch-promedia-2-1/4014-3179_9-9807237.html?ar=o&tag=pdtl-list) is the link for the cnet specs. but since CNET is the only source i could find with impedance, lets assume that the sattelites ARE 4ohm.

The center speaker im trying to wire in is a JBL EC35, 8ohm impedance.

i was hoping that if i was to wire the center speaker speaker into both amp speaker outputs, as if running a bridged setup, i would end up with 6 ohm resistance on both side (assuming the satellites are 4ohm).

if not

im just confirming that if i wire the 2 satellites in paralell to one side and the center speaker on the other, i would end up with 8ohm on both sides? and the amp would be alright with that?

btw, ive tested just replacing a satellite with the center speaker, all works well and the sound is about the same level as the satellite, though much cleaner.

i kno this is an odd setup but the center speaker is unused for now, sooo...if it works...y not? thanks for any help guys.

Targus
07-03-07, 06:07 PM
im just confirming that if i wire the 2 satellites in paralell to one side and the center speaker on the other, i would end up with 8ohm on both sides?

Two 4 Ohm speakers in parallel, results in a 2 Ohm load.

i was hoping that if i was to wire the center speaker speaker into both amp speaker outputs, as if running a bridged setup,

The center speaker would reproduce only the difference between the left and right signals.

Ratman
07-03-07, 07:04 PM
http://www.termpro.com/articles/spkrz.html
http://www.bcae1.com/spkrmlti.htm
http://www.bcae1.com/srsparll.htm
http://www.hometoys.com/htinews/jun05/articles/nigelb/speakers.htm
http://www.audioholics.com/education/loudspeaker-basics/loudspeaker-impedance-series-parallel-connection-basics

ChrisWiggles
07-04-07, 12:18 AM
i was hoping that if i was to wire the center speaker speaker into both amp speaker outputs, as if running a bridged setup, i would end up with 6 ohm resistance on both side (assuming the satellites are 4ohm).

Um, if I follow you correctly, you would be connecting ONE speaker two TWO amplifiers, is that correct?

If so, do NOT do that, you will blow up the amplifiers, that's like connecting the amplifier outputs directly to each other. So, that's the 'why not.'

If you want to add a center channel, you'll need at least a basic pro-logic decoder and an amplifier to power that channel.

C.D.
07-04-07, 02:39 AM
so, wiring the center speaker in a bridged manner wont work.

so i will be running the center speaker from the RIGHT speaker output of the amp, presenting an 8ohm load. and i will be running both satellites on the LEFT speaker output wired in series to give an 8ohm resistance.

then i am only confirming that presenting an 8ohm load on the puny amp wont damage it? (as suppose to a 4ohm load on both sides)

thks for the help

soundlovr
07-04-07, 02:39 AM
Ya, what Chris said :p That's not a bridge it's a bomb.

I'm not sure what you're going for. A centre channel with no centre-channel information is confusing. What would you hope to be adding to your system? You'll only be ruining the imaging information and degrading your sound.

whoaru99
07-04-07, 04:14 AM
You can run a speaker using the left + and right + terminals of the amp. It's not really a center channel speaker, but it does add some ambiance effect and causes no damage to the amp.

So, you'd run one satellite from the left channel, one satellite from the right channel, and the third speaker connected to the left + and right + terminals.

Kal Rubinson
07-04-07, 11:16 AM
so, wiring the center speaker in a bridged manner wont work.It will work but it will play a difference signal, not a sum. Doing that will not fill the center but create the illusion of excessive separation.

so i will be running the center speaker from the RIGHT speaker output of the amp, presenting an 8ohm load. and i will be running both satellites on the LEFT speaker output wired in series to give an 8ohm resistance. That will also work but, again, is almost certain to give you annoyingly unbalanced sound.

stockracer
07-25-07, 10:30 AM
Newbie hoping for help here... Until I get some real speakers, I want to use the satellites from my old Klipsch Promedia 5.1 system with my Onkyo 805 AVR. Do I need to use any special impedance settings on the AVR for this setup? The specs on the Klipsch site do not give the impedance. Thanks!

Kal Rubinson
07-25-07, 10:58 AM
Newbie hoping for help here... Until I get some real speakers, I want to use the satellites from my old Klipsch Promedia 5.1 system with my Onkyo 805 AVR. Do I need to use any special impedance settings on the AVR for this setup? The specs on the Klipsch site do not give the impedance. Thanks!Does this speaker system even have speaker-level inputs?

stockracer
07-25-07, 09:03 PM
Does this speaker system even have speaker-level inputs?

No. I'm talking about a setting on the receiver that I'll be connecting the speakers to.

From the manual:

You can connect speakers with an impedance of
between 4 and 16 ohms. If the impedance of any of the
connected speakers is 4 ohms or more but less than 6,
be sure to set the speaker impedance to 4 ohms (see
page 45).

I've heard that these speakers might be 4 ohms, but I'm not sure.

Kal Rubinson
07-26-07, 01:05 PM
Quote:
Originally Posted by Kal Rubinson
Does this speaker system even have speaker-level inputs?
No. I'm talking about a setting on the receiver that I'll be connecting the speakers to.
Not what I asked.

stockracer
07-26-07, 02:41 PM
Quote:
Originally Posted by Kal Rubinson
Does this speaker system even have speaker-level inputs?
Not what I asked.

I guess I'm not understanding your question, or why you're asking it...

Here's the setup.

Audio source ---> Onkyo AV receiver --> Up to 7 surround speakers (this is where i would use the klipsch surrounds).

I don't see where I have a need for speaker-level inputs.... This would be an amp function, right? Only needed if your audio source has speaker-level outputs.

I just need to know what the impedance is for these speakers.

Kal Rubinson
07-26-07, 03:04 PM
I asked if the SPEAKERS had speaker-level input connectors (binding posts, spring terminals)as opposed to line-level connectors (RCA, 1/8", etc.). The reason I asked is that they are computer speakers.

However, I looked up the user's manual (no useful specs) and see that the satellites will take 22ga wire connections and are meant to be wired through the subwoofer which, presumably, has amps for them. Not that this helps you with the impedance issue but, frankly, I would not connect these speakers directly to your AVR. It is not clear how much power these can handle and they are crossed over at 140Hz(!), much too high for good integration with the sub.

Sorry.

stockracer
07-31-07, 10:14 AM
Ok, well I did it! I already have a good receiver (Onkyo TXSR805) and a great sub from SVS. I just don't have the rest of the speakers yet. I hooked up all 5 speakers from my old Klipsch Promedia system and set the receiver speaker setting to 4 Ohms. I ran the Audyssey speaker setup. It actually sounds really good. I wouldn't say stellar performance, but very adequate for a temporary solution. I'm quite happy with it. No speakers or amps were harmed during the conduct of this experiment.