[SFOX]

I am considering bi - amping my PMC IB1-S with 4B-SST2 (existing) for bass and 2B-SST2 (would be purchased) for mid and tweeter

Any suggestions on this would be appreciated ...


Steven

[James Tanner]

Hi Steven,

The "gain" is the same on all SST-2 amps so you will not have issues with frequency balance mating the different power power ranges of the different Bryston amplifiers.

james

[SFOX]

James

Thank you for response. Could you advise how to connect BP-26 preamp to both 4B-SST2 and 2B-SST2 amplifiers using XLR interconnects and if any revisions are required to passive crossover in IB1-S ...


Steven

[James Tanner]

James

Thank you for response. Could you advise how to connect BP-26 preamp to both 4B-SST2 and 2B-SST2 amplifiers using XLR interconnects and if any revisions are required to passive crossover in IB1-S ...


Steven

You would have to use an XLR "Y" cable but no changes in the crossover except to remove the "LINKS" on the IB1's.

james

[vegasdave]

There's only one pair of XLR outs on the BP26? I thought there were 2!

[James Tanner]

There's only one pair of XLR outs on the BP26? I thought there were 2!

2 pair XLR ins - 1 Pair out
2 pair - RCA outs.

james

[Mad Mr H]

Hi,

If possible I would guide you towards a second 4B SST2.


The 2B SST2 works fine as mentioned,

If you went for a 4B SST2 then it brings one additional option into the mix.

With a pair of 4B SST2 you can place one near each speaker and reduce the length of speaker cables, this brings advantages that if this suits your situation people can go into more detail for you.

This is called "vertical passive bi amp" . One amp per speaker, 1ch bass / 1ch mid/hi

As the 4B is a "dual monoblock" design there is no technical reason not to do this.

If you wish to keep the amps together then two 4's still works.


James - Is there any other technical advantage with the SST2 series of a pair of 4's over 2+4 combo?

Andy.


(PS - Vegasdave -  outputs on the 25/26 caught me out in the past as well !!!

[James Tanner]

Hi Andy,

No technical advantage other than having a lot more power than the 2B of course - and I have always preferred the same amplifiers when it comes to passive biamping.

james

[Mad Mr H]

I have always preferred the same amplifiers when it comes to passive biamping.
James

Me to.

I do think that a 4 offers more for the future.........you could add 7s for IB2/MB2/BB5.

I have never had a 2 series (3,4,7,14 yes) , I do have a feeling that a 2 on the mids will reduce quality that you are used to with the 4, and that I would stick with a single 4 until a second 4 is possible (or 3 that also has future options). I usually only post from experience, this time is one of the very few that is "just a hunch" but based on bi amp experience .I am looking to change my mids 4B to 7's for my BB5's, I have bi amp all 7's on my MB2's. I prefer the 7s on the mids to the 4 - So thats why I "have a hunch" that a 4 will shine over the 2.

If you can ask you dealer for a demo I would love to hear your thoughts, 2 vs 4 on the mid/hf and also if the 4 is next to the speaker as close as possible vs say 8 foot cables..........

Andy.

[SFOX]

James

1 XLR Y-cable from BP26 LH output to separate amplifier LH inputs and same for RH output ...

Is the 2B-LP (non 'pro' version) still available as an alternative to the 2B-SST2 and if so is it available with 'C series' cosmetics and what is Canadian MSRP


Steven

[James Tanner]

James

1 XLR Y-cable from BP26 LH output to separate amplifier LH inputs and same for RH output ...

Is the 2B-LP (non 'pro' version) still available as an alternative to the 2B-SST2 and if so is it available with 'C series' cosmetics and what is Canadian MSRP


Steven

Hi Steven

The 2B-LP is still available but only in Pro version black 19.
http://bryston.com/2blppro_m.html

james

[vegasdave]

2 pair XLR ins - 1 Pair out
2 pair - RCA outs.

james

Cool, thanks.

[Robert D]

Steven take a look here

I'm sure it will Help

http://www.symphonysound.com/articles/biamp.html


Robert

[SFOX]

Thank you all for your suggestions

As mentioned, my system is IB1-S with 4B-SST2, BP-26, MPS-2 and BCD-1 connected with Bryston XLR interconnects - speaker cables - power cables

I have some 'hobby funds' available and am simply looking for another Bryston component / something to add to my system ...

(PS - I tried the BDA-1 with the BCD-1 and sold it as I did not discern any audible difference to upgrade to the 4B-SST2 from 4B-ST)


Steven

[nikon]

found this on the 'net FWIW ...


CROSSOVER THEORY 101

Most speakers have a crossover which splits the total frequency range into that which the drivers can cope with.

If a speaker has 2 or 3 sets of binding posts, all this means is that if the jumpers are removed, each set of binding posts leads to a different section of the overall crossover which can work independently of the rest.

In a 2-way system, with 2 sets of binding posts, you would have one amp feeding the woofer and another feeding the tweeter.  The lowpass crossover prevents the high frequencies from reaching the woofer and the highpass crossover stops low frequencies from reaching the tweeter.

So it's not correct to think of this situation as ‘allowing some current to go to the other drivers’.  Each amp is only dealing with one driver but there is still some power being lost in the crossover ... but less than if one amp was feeding the entire crossover.

The above is a simple arrangement and all it needs is a second (stereo) amp ... as long as your speakers have 2 sets of binding posts.  The next stage ‘up’ is to go active.  This means the passive crossover components are removed so all you have left in the speaker cabinet is the raw drivers ... with appropriate impedance compensation.

You would then insert an active crossover after the preamplifier and feed the two amps with the output of this crossover.  However, the amps are then directly connected to the drivers so you might be in trouble if your tweeter amp has a loud ‘power-on thump’.

[Mad Mr H]

PS - I tried the BDA-1 with the BCD-1 and sold it as I did not discern any audible difference to upgrade to the 4B-SST2 from 4B-ST

Steven

Hi Steven,

Thanks for all the info on your sytem, that is a great help in helping you.

I think the above quote is the key.

We all know weakest item is the bottleneck in any system.

Your use of the BDA-1 in your system showed no audible difference an for that reason correctly you moved it on
Again correctly in my opinion you upgraded the ST series to the SST². I have been very happy to change all my ST series to SST (Cant afford SST² yet).

So, Your baseline for your system quality was as follows

IB1-S 4B-ST BP-26 MPS-2 BCD-1 XLR interconnects - speaker cables - power cables

Add BDA-1 , Baseline unchanged, removed from system.
Exchange 4B-ST for 4B-SST² baseline improved new system baseline

Now you have a different system your baseline reference point for quality of you system has changed and improved. (not all steps are forward)

As the BDA-1 showed "no change" this should still be in your "to try" list. WHY? Well your change of amp shows the bottleneck was infact the amp, the BDA-1 had nothing to offer due to this bottleneck, If you had felt the BDA-1 reduced quality then it should not be in the "to try" list. What is important is what you thought about changes in your system, reviews all say how excellent the BDA-1 is but NONE of these are your system, in your room with your ears, so a great guide but you are the only person that matters.......

So I would sugest you went back and tried a BDA-1 again (With AES/EBU input). What do you think?
(I have gone back to BP25 for very similar reason! following ST to SST upgrades)

Now I understand you have $'s to spend and at about the 2B SST² value I would be blunt to say don't spend those $'s just because you can afford the 2B, Save more for the 4B or consider other options, The "other options" I see you are already considering so how about the following.

TORUS - I don't have TORUS units (im in the UK) but I do use mains conditioning in my systems. The SST² series mention in the spec use of "torus principles" so from that I would suggest thought of mains condtioning for the other source units - Unless the MPS2 offers this?

BE HAPPY - I struggle with this, So I understand this is the most difficult - Maybe your system is already as good as it can be? And that the your current available funds wont improve it? So resist the "upgrade bug" go and buy some cd's sit back nd enjoy what you have - That has to be the hardest option (for me).


I would try the BDA-1 again, buy some CD's,Save more (4B,7B, MB2?), consider the 2B - Thats my current order based on your info.

Enjoy the music, See what you think?

Andy.

[Stu Pitt]

I'm sure others with more experience/knowledge will chime in, but I'll give it a go...

When you bridge an amp, I believe the amp sees a different impedence load.  That could compromise sound quality.

Some people bi-amp using one amp for each speaker - Left output to highs, and Right output to lows.

Others bi-amp using one amp for lows on both speakers, and the other for highs on both speakers - Amp 1's Right output to Right speaker's highs, and Left output to highs on Left speaker.  Amp 2 is the same way, but outputting to lows on each speaker.

The second way makes most sense to me.

I haven't bi-amped in my own system, but have heard a number of systems that were.  I've found that it's best to use the best sounding amp on the highs, if both amps aren't identical.  People tend to use the most powerful amp for the lows, but sometimes the higher powered amp sounds better.  Highs are a lot more difficult to get right than lows are IMO.

I've tried bi-wiring speakers and never really thought it was worth it.  Instead of bi-wiring, I've always replaced the brass jumpers with short strips of the speaker cable I'm using.  That's always been an improvement, and it's usually a lot cheaper.

So in a nut shell, my advice is to try bi-amping with one amp for the highs, and one for the lows.  If bridging sounds better, try using a short strip of speaker wire to replace the brass jumper on the speakers.  If it sounded better before you changed it, nothing lost other than a few minutes fooling around with this stuff.  At least you'll know what you have definitely sounds best.  Everyone's ears are different.  There's really no one right way.

[Vipers]

Just been reading through this thread as it is very relative to me also as I'm in the process of selling my EB1i's to move upto MB2i's and the dilema I have at the moment is do I add another 4B SST2 to my existing 4B SST2 to bi-amp as I have my doubts as to whether 1 x 4B SST2 will do the MB's justice, or as my 4B is only 6 months old, do I sell it and hopefully not loose too much money and buy 2 x 7B SST2?

Until today I was origianlly just going to add another 4B SST2 but I guess that 2 x 7B's would be the way to go, but at £4700 each I need to get good money for my 4B.

What advantage would the MB2i's get with 2 x 7B SST2 against 2 x 4B SST2 Bi-amped?

[srb]

What advantage would the MB2i's get with 2 x 7B SST2 against 2 x 4B SST2 Bi-amped?

If the woofer and midrange+tweeter used the same amount of power, it would probably be a wash.  But because the woofer uses a lot more power than the midrange+tweeter, the woofer would not have access to the power reserves that would be available from a twice as powerful amplifier.
 
Many people who have tried passive bi-amping got better sound and improved dynamics using a single amplifier that was twice as powerful.
 
Steve