2 sets of different speakers on one amplifier

 

rio1242
Unregistered guest
I own an amplifier which has the ability to drive two sets of speakers as A+B. if i hook two different
sets of speakers with the same ohms but with different watts and sensitivity will i have problem with my amp?or will the temperature increase or something? does that reduce power?i really want sound clarity so please help. thanx
 

New member
Username: Nerd

Phila, Pa Usa

Post Number: 1
Registered: Nov-04
a=b should not be used at the same time espacialy if the speakers are not the same. You can do it but you well notice the diffrence in the sound tone than if you just set up one pair.some people like to use them at speart time for diffrent type of music.
 

rio1242
Unregistered guest
Ok, if I am going to have a problem with the sound, I won't do it. Thanks Nuruddiyn.
 

Bronze Member
Username: Natediggidy

Baltimore, Maryland U.S.A.

Post Number: 66
Registered: May-04
It's not quite that simple for several reasons. Watts has no bearing on whether one pair of speakers is compatible with speakers. If they're the same ohm rating and no lower than what's recommended (usually posted at the amp speaker connections), then you'll be O.K. If they have different sensitivity ratings, one set will simply be louder. If you're playing them so loudly that one set begins to distort before the other, then turn it down some.
Now you have to consider sound quality issues. Some amp's speaker switches are designed to connect the A+B speakers in series to keep the amp safe from too low of an impedance load. If you switch to speakers "A+B" with only one set of speakers attached and you get no sound, this is the set-up you have. With this type of circuit, the impedance that your speakers internal crossovers "sees" rises, changing the crossover points and changing how they sound. With a parallel circuit, this dosen't happen but the amp will run warmer. As long as you have adequate ventelation, things should be O.K. The speakers may or may not sound good played together tho'. No way to know until you try.
 

rio1242
Unregistered guest
The amp circuit is parallel for A+B. If i choose a pair with the same sensitivity but lower watts the only thing that will happen is that they may have different sound? i already have the B&W DM604 S3 and i was thinking about buying the 602 as B. I'm not going to buy them before someone tells me if there is any point in doing that.
 

Silver Member
Username: Carguy

Post Number: 475
Registered: Nov-04
Guy, you can mix and match speakers as long as you keep an eye on the ohms. 4 pair of speakers will sound better than 2 if they're good quality.
I've done it many times. They don't have to be the same brand/model. If one's stronger than the other, then that one will sound louder. No need to worry.
 

rio1242
Unregistered guest
Both speaker sets have 8 Ohms of impedance (and 3 Ohms minimal impedance). Since the circuit is in parallel the total impedance will be 4 Ohms (and 1,5 ohms minimal), right? Which spec of the amp should I check to see if I am going to have any problems with this set-up?
 

Silver Member
Username: Carguy

Post Number: 494
Registered: Nov-04
Hey rio1242, 8ohms in parallel will give you 4ohms impedance.
This is what I found with different amps. The ones that offer you A/B, you can only use one or the other. The amps that give you both A/B and A+B, they'll drive both speakers without any problem (4ohms capable).
If you have the amp's manual, in the spec section, look for output power, it'll list the load impedances that are compatible.
 

rio1242
Unregistered guest
Thank you Isaac. I will check it out.
 

New member
Username: Pocoman

BC Canada

Post Number: 1
Registered: Dec-04
Hi, I'm new to this board but not to stereo or hifi. I have one of the famous Technics "New Class A" amps (SU-V707) from the 80's and although it's been very satisfactory with plenty of oomph for my setup, it's been a little troublesome lately and I'm now looking to replace/upgrade it. After looking around a bit I find that many decent reasonably priced amps (e.g. Parasound Halo) do not have the A/B/A+B speaker capability that I need to feed two separate rooms from the same amp.

My question is, can I operate a separate speaker switch box off the single output safely? I guess that such a box would simply parallel the speakers so my two sets of 8 ohm speakers would wind up being seen by the amp as one 4 ohm set, which should be OK.

Any comments?
 

Silver Member
Username: Carguy

Post Number: 936
Registered: Nov-04
Hey Bryan, that'll depend on the amp itself. Some of them will operate safely at 4ohms, while others don't. From my experience, as long as you're not blasting the stereo full blast, it will handle 4ohms without much problem.
You can buy the external speaker switch and use it without any problem. I've done it.
 

Bronze Member
Username: Nuck

Parkhill, Ontario Canada

Post Number: 16
Registered: Dec-04
It goes like this,
1over/ 1 over r1+ 1/r2, etc for parallel resistance. Sorry, can't draw it.
 

Unregistered guest
Hey Guys question,
I recently purchased some 6 ohm Germany made speakers to run on a 8 ohm amp. I sensed a power loss when I hooked them up. Am I doing something wrong.....Help
 

Gold Member
Username: Carguy

Post Number: 1243
Registered: Nov-04
That didn't make any sense. It should be the other way around. As you go lower in ohms, it should sound louder. Most amps will produce more power at lower ohms. However, going below the recommended ohms will burnout your amp.
If by hooking up your new speakers lowers the power, you either have a very weak amp or your speakers are bad quality. A difference of 2ohms shouldn't cause power loss in amps. Make sure your pos and neg terminals are connected properly.
 

Anonymous
 
joeman12
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