Amp output is wired in series vs parallel?

This is an old thread but I was playing with this on my used 7BST’s I just picked up.  I bi-wired to my speakers. My assumption is I now have a fight current connection to the LF binding posts and a high current connection to the HF binding posts.  Is this assumption correct?

that being said, I don’t see any speaker manufacturers listing the impedance of the LF and HF connections individually.  They only list the speaker as a whole or “nominal 4 ohms”

I am guessing I can connect one of those Parts Express speaker testers to it to see what the impedance curve looks like.  I am assuming they will be 8 ohm loads and with the bridging clips in they would parallel down to 4 ohm loads.  
I have seen different specs on the 7B’s output.  So figuring out what the potential wattage is when in Parallel mode is getting tricky.  The factories final check out slip indicated the output at something like 615 watts.  The literature says 800 watts.  
Either way I felt the bottom end on my speakers seemed to play a little better with the system bi-wired in parallel mode.  

Mitch4t, why not try and then post your findings, if you don't you will never know.

Do you know of anyone else using the same speaker you have, if so what have they tried.

On the SST, parallel operation is a factory option, not a switch like the earlier versions. Should be an easy mod.

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Ngjockey, you are spot on, this whole thread was started with the Kappa 9 in mind. I think bi-amping with two pair of 7B SST might be a better option. Too many questions about the 28B SST low ohm performance. And at $16k per pair for the 28B, I'd need better peace of mind at those prices.
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Ya, definitely oversimplified that at 8:00 AM. Can't deal with current limiting till after the second cup. Thanks Al, for being more precise.

Bryston does use a 1.5 ohm resistor on the parallel 7B's. Not sure about the 28B's. Seen jumper wires for paralleling some Macs that didn't use any resistor. Don't ask me if those were autoformer models. Only other monostrapping I've heard of has been on tube amps, which 95% suggests output transformers. Can't think of any other SS amp manufacturer that has recommended that method.

Mitch, if you're thinking for the Kappa's and maybe even the Beta's, parallel might be the only viable choice of either. However, I did use dual bridged Plinius SA100's on Kappa 8's very briefly and continue to use them with Genesis 350's ( on 4 ohm mid/tweeter, resistive load, dedicated bass amp/active xover). For that one hour on the 8's, it was the best bass I ever got out of them but still sloppy by comparison to the 350's.

Hi Mitch,

In the paralleled configuration, power capability into 8 ohms will be MUCH less than in the bridged configuration. It will probably increase significantly into 2 ohms, and not change dramatically into 4 ohms. And based on JA's comments about distortion, sonics with a 2 to 4 ohm load will most likely be better in the paralleled configuration.

Elizabeth's comment is spot on, with the slight correction that the reference to "pressure (watts)" should say "pressure (volts)."

NGJockey's comment is correct, except for what I suspect is his inadvertent mention of 4x voltage, which should be 2x voltage as Kijanki and Bob pointed out. Bridging potentially increases voltage swing capability by 2x, and power by 4x, but current limitations, thermal considerations, and other factors usually limit those increases to significantly smaller factors into 8 ohms, and to much smaller factors for low impedance loads.

Also, I suspect that the 1 to 2 ohm resistor he mentioned is probably just applicable to some paralleled designs but not to many others. Where a resistor of that large a value is used there would be a major impact on damping factor and output impedance, and therefore on frequency response flatness if speaker impedance varies significantly with frequency. I would suggest that anyone considering purchase of a monostrapped (paralleled) amp ascertain its damping factor before finalizing their decision, and consider its appropriateness for the particular speaker that is being used.

Best regards,
-- Al

Shouldn't it be 2x voltage in bridged?

Series: Same current, up to 4X voltage (often factory derated to handle stress from low impedance loads, ie. lower voltage rails- Aragon Palladiums). True bridged/differential.

Parallel: 2X current, same voltage. To keep sides from conflict, a 1 to 2 ohm resistor is used in parallel. "Monostrapped".

W=V*A