[turnovertherecord]

Speakers are FS-788...10 ohm speakers  ,
www.soundstagemagazine.com/measurements/focus_fs788/

Preamp is BP-25 MC

The pre has only one xlr out ,,so great for bridging,not so good for bi amping,but can use the rca outputs because there are two

I have caused the single 3bsst to clip so I picked up another 3bsst

Anyone with experience in my position

Pro`s and Con`s for either bridging or bi amp

[95Dyna]

When I bought my Infinity 9 Kappas in 1990 the dealer recommended two Adcom GFA 555's to drive them and advised me to bridge them.  It wasn't long before I started popping output stage fuses causing me to do a little research.  Google wasn't available at the time so it took a little longer to discover that in bridged mono mode a stereo amp sees only half the load a speaker is presenting.  My speakers dipped to .8 ohms at 32 hz then again at 340 hz with nasty phase angles easily explaining my problem.

I switched to bi-amping using a Y connector on the single ended output on my Adcom preamp and lived happily ever after until I bought my 7B SST2's in '09 which turned the Kappas into a new pair of speakers making me even happier.

That being said your speaks sound like a very easy load at 10 ohms nominal so maybe you will do alright in bridged mode.  It depends what other behavioral characteristics your amps present e.g. efficiency, phase issues etc.

[turnovertherecord]

I will give bridging a go first ,because it is the easiest ,less cables

[RDavidson]

I'm surprised you made your single 3B SST clip with those speakers. They look to be a relatively easy / average load overall. I must ask a few questions to maybe get to a better answer for you.

1. Is your listening room large?
2. What speaker cables are you using?
3. Is there an EQ in the chain somewhere?
4. Is your system plugged into the same electric line as your home appliances, like a refrigerator?
5. Is the amp plugged into a surge protector or similar device?

[turnovertherecord]

room is 38 X 14

7 awg hybrid bi wire 8 ft

no eq

dedicated 20 amp outlet

no just into 20 amp circuit

using balanced xlr gain at 2v 23 db

[RDavidson]

Interesting. Now I'm really surprised you made your 3BSST clip. Looks like you have a pretty ideal setup.

Regardless, yes, try bridged first, since that is easiest for you as was already suggested......though I'm not sure this will resolve clipping or not. Yes, you'll have more watts, but my guess is your speakers really want more current. To get more current, you'll want to run them (non-bridged) bi-amp mode, which you probably know already. If your amps aren't too far away from your preamp I wouldn't worry too much about not using the XLR's unless your source is also fully balanced.....then I can understand wanting to stay balanced all the way. If this is a case a couple of XLR splitters is your only choice, short of a new preamp.

[turnovertherecord]

after bridging

 

all is well

[mrhyfy]

Sorry to stray,,,,can you sell them and get one 4BSST????

[turnovertherecord]

sold 3 4bsst2,passlabs and a krell

[Ron D]

maybe I'm missing something here but factoring in the fact you had a 4B-SST as well as other (I assume) higher wattage producing amps, whats your perceived benefit to using 3B-SST X 2?

Is it because you can run them like mono-blocks and place them close to the speakers thereby reducing the length of speaker cable you need? Don't quite understand the root benefit to bridging two 3B amps?

Maybe I just don't have enough coffee in me yet...

[turnovertherecord]

maybe I'm missing something here but factoring in the fact you had a 4B-SST as well as other (I assume) higher wattage producing amps, whats your perceived benefit to using 3B-SST X 2?

Is it because you can run them like mono-blocks and place them close to the speakers thereby reducing the length of speaker cable you need? Don't quite understand the root benefit to bridging two 3B amps?

Maybe I just don't have enough coffee in me yet...

I have had some other amps,some ok some not ok to me

I have had my speakers for a long time

To date the best to me was my bryston mcIntosh setup

Borrow a 3bsst from a friend,liked the sound of the 3bsst as compared to the others,so sold of others,purchased some vinyl

I used a bp-26p ,but no mc so purchase a bp-25 mc,very happy with this pre

so I ended up with a bp-25 mc and a 3bsst ,until one day I turn up volume and 3b went red

I found out I could bridge the 3b,I than purchase another 3bsst,bridge the amps,now it does not clip

I will try to bi amp to check for heat and clipping,if no problem than I will chose what sounds best for me

The bp-25 has two rca out,I will use single ended out to amps,so no splitter needed,I will have to verify if this is a way to bi-amp

 

[RDavidson]

If you bi-amp via the method described (un-bridged), I'd set it up so one amp powers the left speaker and the other powers the right. I think this is what you had in mind already anyway.

Another method would be to vertically bi-amp, where one amp is hooked up to the upper range drivers (of both speakers) and the other is hooked up to the lower range drivers (of both speakers). I don't think this is preferable as you'd give up the channel separation provided with bridging and/or bi-amping option 1, but just something else to try on a rainy day if you feel like tinkering.

[turnovertherecord]

The end result would be to not have amp clip

Along the way to this end,trying different configurations is experience I will have going forward as I have not done this before(bridging and bi amp setup) 

[RDavidson]

Understood. If you're not clipping in bridged mode, then you most definitely won't be clipping via un-bridged bi-amping.

If I'm wrong about this, someone please chime in. But the "problem" with bridging, is that the amp is no longer using it's full power supply. What's happening in bridged mode is that you're using the output devices for both channels (so you're able to double the output wattage from a single channel), BUT not both power supplies / both sides of the power supply are used. Basically, you get more watts (due to use of all output devices), but you've cut your total current in half (as only the power supply for one channel is used). Power supply doesn't get bridged.

[turnovertherecord]

no clipping after bridging

will passive bi amp after weekend,to check clipping

[brucek]

.............I will use single ended out to amps, so no splitter needed......

Why would you not use XLR out with a splitter. Is the splitter a concern to you?

If so, why?

brucek

[95Dyna]

Understood. If you're not clipping in bridged mode, then you most definitely won't be clipping via un-bridged bi-amping.

If I'm wrong about this, someone please chime in. But the "problem" with bridging, is that the amp is no longer using it's full power supply. What's happening in bridged mode is that you're using the output devices for both channels (so you're able to double the output wattage from a single channel), BUT not both power supplies / both sides of the power supply are used. Basically, you get more watts (due to use of all output devices), but you've cut your total current in half (as only the power supply for one channel is used). Power supply doesn't get bridged.

Another way of saying what I said in the first post.  I agree with you and maintain that in this scenario as presented by the author vertical bi-amping using a splitter on your preamp outs is the way to go.  Experience with a pair of one of the most the most notorious amp killers ever designed tells me so.

[turnovertherecord]

The bp-25 has 2 pre outs single ended,one for each amp

I will do this first as I have the IC`s on hand,distance from pre to each amp is 3 ft


https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CDQQFjAE&url=http%3A%2F%2Fsites.thestar.com.my%2Faudio%2Fstory.asp%3Ffile%3D%2F2003%2F6%2F26%2Faudiofile%2F26bryston&ei=2JasU9XhA46YyASHq4CwAg&usg=AFQjCNHFcGghREouxv4JzizbMnat6nW4sQ

[turnovertherecord]

After bi amp,no clipping,sound is where all is good again

[turnovertherecord]

Have my xlr splitters 6 ft install for a couple day`s now

So after all the experiments,I have to say that biamp the 3b`s is great and no where near clipping