4or 8 or 16 ohms when you have 2 pairs of he same speaker

FONSguy

Super Member
I was thinking of a poll but this needed discussion .

So you have 2 pairs of the same speakers,and have a power amp that can kick ass in any impedance from 2 to 16 ohms. How would YOU connect your speakers. I have 2 pairs of KEF 104aB's connected to a Crown PSA-2 (315 RMS per channel} at 4 ohms. they have punch and nice bass,
 
Two 4 ohm speakers connected in parallel presents 2 ohms to the amplifier. If the manufacturer expressly states the amplifier is designed to drive such a load, this shouldn't be a problem. In any case, the amplfier's protection circuitry should kick in if heat becomes excessive.
 
These are nominally 8 ohm speakers. If you hook them up in parallel to your amp, they will present a nominal 4 ohm load to the amp. However, looks like this amp only has one set of speaker outputs. How do you have them hooked up?
 
Caution is advised. If you only have one set of speaker terminals, that’s all the manufacturer had in mind. Many manufacturers will tell you not to run two pair in parallel, but do as you please.
 
That depends on the unit in question.

The fact that most dedicated power amplifiers only have one pair of output terminals has nothing to do with the load the amplifier is capable of handling. If it designed for 2 ohms, two 8 ohm speakers (4 ohm net) should be no problem.
 
For best sound quality and maximum power I'd run them in parallel. Most power amps have only one set of output terminals, it's trivial to connect two different pairs of speakers, either by using a simple switching unit, using a pigtail, or even just stacking banana plugs.
 
Your amp is rated at 700 WPC into 2 ohms, so this should not be a problem. You don't want to go below 4 ohms in bridged mono mode.
 
Depends on your objectiive.
Amplifiers have lower distortion with higher impedance.
Amplifiers have more power output capability with lower impedance.
Take your pick.
 
If the amp is design for 2 speakers then I hook 2 speakers to it. If I want/need to hook up 4 speakers then I'd buy another amp for the other 2.
 
Depends on your objectiive.
Amplifiers have lower distortion with higher impedance.
Amplifiers have more power output capability with lower impedance.
Take your pick.
I've also heard amps sound tighter, more controlled @ higher impedance.
I'm not sure how true that is though, but if you don't need the extra wattage and since your amp is capable why not try both ways.
 
The suggestion the load an amplifier is capable of dealing with is dictated by the number of speaker terminals is nonsense!

Nearly all standalone basic amplifiers have terminals for one single pair of speakers. That does not mean they lack the ability to drive additional pairs.

Here is an example of an accessory speaker switcher designed for use with amplifiers having a single pair of output terminals.

McIntoshSCR-2SpeakerRelay-D.jpg
 
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I've also heard amps sound tighter, more controlled @ higher impedance.
I'm not sure how true that is though, but if you don't need the extra wattage and since your amp is capable why not try both ways.

A higher impedience speaker will typically have a higher Bl. The Bl is a measure of how well the speaker controls the cone movement with a higher value having more control.
 
I do not believe in running speakers in series when not necessary. Speakers are not simple resistive loads, the load reactance varies, cone movement & overshoot can create transients that the amplifier is supposed to shunt but in the case of series it can cause oscillations, imperfectly matched speakers (drivers, crossovers, etc.) will cause other potential phasing and imaging problems, ... all theoretical of course but it's not a perfect world and speakers are not perfectly matched.
 
I do not believe in running speakers in series when not necessary. Speakers are not simple resistive loads, the load reactance varies, cone movement & overshoot can create transients that the amplifier is supposed to shunt but in the case of series it can cause oscillations, imperfectly matched speakers (drivers, crossovers, etc.) will cause other potential phasing and imaging problems, ... all theoretical of course but it's not a perfect world and speakers are not perfectly matched.

I've never tried wiring together speakers that weren't the same model... now you've got me wanting to play but I probably shouldn't.
 
I do not believe in running speakers in series when not necessary. Speakers are not simple resistive loads, the load reactance varies, cone movement & overshoot can create transients that the amplifier is supposed to shunt but in the case of series it can cause oscillations, imperfectly matched speakers (drivers, crossovers, etc.) will cause other potential phasing and imaging problems, ... all theoretical of course but it's not a perfect world and speakers are not perfectly matched.
Do what? Who told you that?
 
Do what? Who told you that?

Electronics 101.

The amount of change will vary, likely the smallest with speakers of the same model and the greatest with non matching speakers. The resulting impact on sound quality is of course subjective, but the science is not.
 
It is not something that I would normally do, but I have. The end result perception of the result is in the ear of the listener.

Some that operate speakers is series, whether they are the same model or not like the sound quality and others not so much.

Some receivers will connect speakers in series when two pair are selected. My Kenwood KR-6160 does this. Of course it is not at the top of the audio quality food chain.
 
so series is no good?

Not "no good", if the equipment is rated for the combined impedance it shouldn't hurt anything.

Another thing to consider is output voltage (volume) vs amplifier current load: In series, you are sending half of the voltage (volume) to each speaker. In parallel you are sending more voltage (volume), but requiring twice the current (load) of a single speaker. If you are running high volume/SPLs, you might get into clipping at a lower volume in a parallel arrangement than in series if your amplifier isn't able to deliver the current (your Crown is probably fine based on its ratings). Also, it will likely run cooler in the series arrangement.

So there are a lot of variables and remember that the easiest way to describe double the output power is a just noticeable difference in volume, ... so don't expect twice the volume (SPL).

Putting four speakers on a two-channel system even if the same model of speaker can change a lot of things including phase relationship / imaging etc. and it really is more of an opportunity to experiment and see what you like or don't like. It's a hobby with the reward of experimenting and of enjoying the results of what you build, so when there's no risk to the equipment such as in this case, ... just try things until you like the result and don't concern yourself about the purist mentality.
 
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