Bi-amp/wire LSiM 703s

hoosier

I just purchased a pair of 703s during the recent F&F sale. For now they with be used in a 5.1 HT with an older Sony ES SC-25 HT receiver. The SC-25 has 2 un-used amp. Is there any benefit to remove the 703 jumpers and bi-amp/wire them?

hochpt21

Bi-amping from a receiver won't produce additional benifits.

If you already have bi-wire cables, remove the jumpers and go for it.

Otherwise, just get some 10 gauge cable and make your own jumpers for them.

I've done a lot of research and some real life experimenting. Looking at your current setup, I would put said money into other aspects first.

tonyb

hoosier wrote: »

I just purchased a pair of 703s during the recent F&F sale. For now they with be used in a 5.1 HT with an older Sony ES SC-25 HT receiver. The SC-25 has 2 un-used amp. Is there any benefit to remove the 703 jumpers and bi-amp/wire them?

The benefit is already there by not using those extra 2 channels. The other channels are receiving more current by not using them.

Other than that, always a good idea to replace those jumpers with quality wire of the same gauge as your speaker wire.

don0

tonyb wrote: »

hoosier wrote: »

I just purchased a pair of 703s during the recent F&F sale. For now they with be used in a 5.1 HT with an older Sony ES SC-25 HT receiver. The SC-25 has 2 un-used amp. Is there any benefit to remove the 703 jumpers and bi-amp/wire them?

The benefit is already there by not using those extra 2 channels. The other channels are receiving more current by not using them.

Other than that, always a good idea to replace those jumpers with quality wire of the same gauge as your speaker wire.

This is just a question and not an argument.
Would the speakers not use the same amount of current from the power supply when bi-amped as when using a single wire with jumpers in place or would they be harder to drive when bi-amped?

F1nut

The more channels used, the less power per channel you get.

tonyb

don0 wrote: »

tonyb wrote: »

hoosier wrote: »

I just purchased a pair of 703s during the recent F&F sale. For now they with be used in a 5.1 HT with an older Sony ES SC-25 HT receiver. The SC-25 has 2 un-used amp. Is there any benefit to remove the 703 jumpers and bi-amp/wire them?

The benefit is already there by not using those extra 2 channels. The other channels are receiving more current by not using them.

Other than that, always a good idea to replace those jumpers with quality wire of the same gauge as your speaker wire.

This is just a question and not an argument.
Would the speakers not use the same amount of current from the power supply when bi-amped as when using a single wire with jumpers in place or would they be harder to drive when bi-amped?

Depends....like F1NUT said, the more channels used, the less power all channels get. When talking receivers, the best scenario is 2 channel mode, so all the power is applied to just those 2 speakers.....regardless how it's wired up.

That's best case for a receiver to output power, next is getting it to the speakers. The appropriate gauge wire either to one post or both on the speakers is essential. When using jumpers, wired jumpers, you'd want the same gauge and brand as the main speaker cables.

Talking receivers, that's about as much as you can do to get power out of them, everything else is marketing hype. This is why, instead of looking at gimmicky bi-amp features many tout, you should be looking to see if you have pre-outs to add a dedicated amp down the line should the need for more power arise.

txcoastal1

Here is a perfect example of an amps specs that portray one thing and actually do another once you dig in. The front of the cut sheet says it's a 50watt per channel amp, but this is true only under certain conditions.

[/quote]Audio - 2 Channel Mode
Rated Power/Channel 30 Watts, 20Hz to 20KHz
(RMS, 2 channels driven into 8 ohms)

Power/Channel 50 Watts, 20Hz to 20KHz
(RMS, 2 channels driven into 4 ohms)

1KHz testing
IHF Dynamic Power 40 Watts/1KHz at 8 ohm load
60 Watts/1KHz at 4 ohm load

Anything above 20W will add additional Harmonic Distortion
Total Harmonic Distortion @20W/8ohm, 0.5%[/quote]

tonyb

I still like my car analogy. Think of your car, it's engine is the same as the power supply in a receiver. It's torque is the same as current. Driving just the 2 rear wheels, you can lay some rubber, but if that same engine drove all 4 wheels, and in a receivers case 5 or 7 channels, that power is spread out and none will have the ability to lay rubber.

So if your not using additional channels on a receiver, that's a good thing. Remember, a receiver is a jack of all trades, master of none. It can be all things to some people in one tidy box. It's main objective though is HT. Unfortunately all but the top of the line receivers have limited torque to drive more demanding speakers so your limited in speaker choices. Unless you have preouts to add an amp, add a bigger engine with more torque.

Sooner or later we all want bigger and better speakers, you just have to consider the needs to power them too, without trying to McGiver a receiver to do it because that's a futile road to go down.

hoosier

Thanks all - I did not biamp or biwire. Just added the 706 center channel. What a monster!

Now wondering about the benefit of adding an external 5 channel amp? I know the 703's and the 706 are supposed to be easier to drive than the previous models. By the the way, the 703's and the 706 has pretty hefty jumpers. Still recommend replacing the jumper? Also looking a some DYI douglasconnection cables.

Legender

tonyb wrote: »

I still like my car analogy. Think of your car, it's engine is the same as the power supply in a receiver. It's torque is the same as current. Driving just the 2 rear wheels, you can lay some rubber, but if that same engine drove all 4 wheels, and in a receivers case 5 or 7 channels, that power is spread out and none will have the ability to lay rubber.

So if your not using additional channels on a receiver, that's a good thing. Remember, a receiver is a jack of all trades, master of none. It can be all things to some people in one tidy box. It's main objective though is HT. Unfortunately all but the top of the line receivers have limited torque to drive more demanding speakers so your limited in speaker choices. Unless you have preouts to add an amp, add a bigger engine with more torque.

Sooner or later we all want bigger and better speakers, you just have to consider the needs to power them too, without trying to McGiver a receiver to do it because that's a futile road to go down.

So... following that analogy (pretty good), then I need an engine (amp) for each wheel pair and I could really tell a difference?

tonyb

Not necessarily for each pair. The front left and right and center do all the heavy lifting, those should be on an amp. Surrounds usually only do ambient sounds, not too demanding, and if your receiver is decent and speakers fairly efficient, you can get away with letting the receiver handle the surrounds.

Yes, you will hear a difference with an amp btw.