To bi-amp, or not to bi-amp, ...

... that is my question

"Whether tis nobler in the mind to double
the watts and class at outrageous fortune
or bi-amping single-end them.

Hifi - to sleep no more; and by a sleep to say we end
the heartache and the thousand natural shocks
that pocket is heir to. " (with all due apologies ..)

Is it 'better' to have two 60W amps, bi-amped, or a single 120W amp? (60 and 120 chosen as examples.)

Although this is a general, open-ended question, I have a particular puzzle:

Dax Decade has pair of single ended output (therefore suitable for bi-amping), and I now use of pair to feed into a 60W poweramp (the AudioLab 8000S in poweramp mode) and single-wire to JM Lab Electra speakers, which can be bi-amped.

I found the bi-wiring debate useful, and stopped be attempting tweaks in that direction.

Have been looking & listening to alternative poweramps, but for the extra dosh the difference over the performance of the 8000S is much less VFM than other upgrades thus far - which I think is a tribute to the 8000S, though I do know that it could do with a bit of help with extra grip on the JMLabs that results in tigher and more pronounced bass (the DaxDecade feeds it v.good 'organic' and well-defined signal). I've noticed that the Tag 60P is now less than £350, and was touted as greatly helping the Tag60i, which the 8000S probably betters. What chance a bi-amped Tag60P and 8000S, 60 + 60, would do as well as a 120w pair of monoblocs?

Or have I lost the plot? Alas poor Yorrick ....

 

Personally I'm in the "you can never have too much power" camp. Look at it this way - you have 60wpc (I guess) at the moment - when you need that power into the bass/mid driver your amp is going to put it there. Biamp with another 60wpc and the power of the "treble" amp still isn't available to the bass/mid driver. On the other hand, with 120wpc (and lets assume that all else is equal) you can dump all of that power where it's needed.

Of course, put on a wattmeter and it tells you that your speakers never draw more than 10 W - not necessarily true, because the estreme power demands are all in the transients. Worth bearing in mind also, for bass control, is the ability of the amp to soak up back-EMF - in general, the bigger the amp, the better it is at doing this.

Biamping's good, once you've made sure you're getting enough power to the speakers, and to do that you need a bigger amp. So get that first, then think about another one for biamping.

That bigger amp should (chosen correctly) help sort out the bass control you want - and there's not much point going for anything less than twice the power of what you have at the moment.

 

It is, at 8ohms, 60w x 2, tho someone once suggested that it was 60 good watts. I've a pair of Flying Moles on loan at the moment, they are each 100watts at 8. For my bi-amp experiment, the Moles have grip on the LF and the AudioLabs the HF. Its an improvement, especially in the LF.

But I understand your main point - you argue that I need more than 60w x2 in a single stereo (power)amp in order to get the responsiveness when its needed, wherever that is.

I guess the extreme in this argument is the EVo4, is it better to bridge or to bi-amp?

 

Some things to consider with bi-amping.

You need:

Twice as many interconnects.
Twice as many power leads.
Twice as many speaker leads.

If you don't think the cost of the above is an issue then you haven't made the most of your current amplifier and should think about upgrading the above.

Regards
Gary

 

The eVo-4 sounds best bridged.

Regards
Gary

 

Monoblocks would be better IMO. My first hifi setup consisted of a TAG/Audiolab bi-amp connection, and good it was, but 120W of monoblock power is certainly better. The stereo amp, much like the integrated, is still a compromise - splitting power into mono sections is a step in the right direction in terms of fidelity...and you can have nice short speaker cable too.

 

Hi Gary,

I've noted the extra costs, ans degrade opportunity, as you've listed them when setting up my little experiment - nothing quite like a bit of experiential learning. Fortunately, for present purposes at least, the Flying Moles come with their own interconnects and powerleads, the former are VDH I think. And on the speaker cables, I've the Nordost Bi-wire Flatliners, presently twisted and ended to singles. But I do take your point, which applies in small part (powerleads) to monoblocs also.

Your comment about the Evo4, which I see that others also make, is interesting as it suggests that the advantages of bi-amping are conjecture, much as bi-wiring, and something the industry would like us to believe.

btw, as indicated in my email, I've been following your discussion with Nic on AVTalk about getting the best from the Dax Decade and since I typically have that digital volume at -28 have been trying to factor that into my decision making about the 'last' piece in the jigsaw, the poweramp. I see that as a bit of a puzzle - a bit of a design issue.

The 8000S, bought on your advice (*) is a mixed blessing. It's flexible, with poweramp mode and switchable to integrated for use with Tuner, and it does well for the price - but I know I want/need to replace it to get the best out of what I have elsewhere and that's not easy, hence my faffing around.

I'm going to home demo the Moon I-5 as a straight upgrade to the switchable 8000S, but have also been checking out the digital amp route (PS Audio, FMoles, TacT). Haven't had a chance to check out the EVo4, but maybe that would give me a bridged pair for HiFi and four of my 5.1??

Anyway, the bi-amped (8000S + FMoles) set-up is fun and an improvement over 8000S or FMoles, but then that's hardly an experimental result I suppose, just confimation that (60+60+100+100) > (100+100) > (60+60). So, if its just a matter of arithmetic ...

Best to you

Peter

* as was Dax Decade of course, even if I then went on and risked your green envy by getting the modded Transcend which has since had Ncode fitted - best upgrade for £50 ! Tho BG upgrade to Decade also worthwhile. Just dont tell me that I really need the balanced model ...

 

I almost leapt into monobloc-land but opportunity was lost, tho I have a home demo of a few models lined up. There seem to be a few dual mono stereo models now which presumably are not compromised. Do you have strong views on the short speakercable vs short interconnect argument? Doesn't it depend on the pre-amp characteristics?

 

I don't have particularly strong views on lengths of cables, as long as the cable is of a high quality and properly shielded then this shouldn't be too much of an issue. I think only passive pre-amps must have shortish interconnects, otherwise you may get high-pass filter characteristics coming into play. Based on my own experience, shorter speaker cable does seem to give the power amp a bit more 'grip' on the speaker. Perhaps there is some importance when considering low and high level signals in each type of cable and its respective length, but I tend to go by what I hear, so I lean towards longer interconnect/shorter speaker cable.

 

Peter

Having tried both bi-amping monoblocs and buying a single better monobloc my advice would be to go for a better quality single monobloc if used with a passive crossover.

A balanced Decade is better than a single ended, however where that fits in the scheme of things in terms of upgrades is difficult to say. With regard to the digital volume I think you will find a pair of decent power leads on the transport and dac will more than make up for the small loss in resolution. I thought the Kristel Kable Mercury was a nice cable at it's price, as was the Missing Link Reference, which, not quite as good, sonically, is better constructed, both are better than the Russ Andrews powercords for not much more outlay.

An eVo-4 may be what you are looking for provided you don't mind swapping the speakers connections when switching between AV and music.


Regards
Gary

 

MrC, thanks for that. I think the Dax Decade does fall into the 'passive' category but I'll see how I might shorten speaker cables.

Gary, I'm using a Eupen on the transport and according to Nic, the Decade inards have enough to protect from mains inducement, so I'm still a little concerned, at the 'logical' level, that setting the dial at -35 (which I note is what it is now with the 60+60+100+100 watts set-up) implies a loss of signal. Perhaps it was better I never was told!! But if W increases so vol dial has to go down ...

So, to answer Hamlet, it is better not to bi, if one can double watt one is ...

edit: I forgot to add a recommendation of my own:

listen to Post-Scritum by Cristina Branco for an excellent recording of 'modern' Fado. I picked in up in Amsterdam but it may be in the shops here. Its now second reference CD after Miles and his Kind of

 

i confess i didn't even think about biamping the e4 - i bridged the bastard and it seemed to work fine

 

If you think its good in single ended, wait to you use the Balanced connections

 

just as I thought I was getting settled!!

 

tony

do you mean those xlr's on the back - how does that all work then?

 

John,

You will need a balanced input source to use them, the difference is not subtle

 

WM

My quest for a new preamp continues although I'm quite a long way from having the spare cash to do this but with a fair wind a new one in the first quarter of 2005 isn't out of the question.

I was thinking along the lines of something secondhand about 2k. What about audio research - i've always fancied one? I mean what's wrong with buying something just cos you like the look of it. What about the xlr's ?

The bc preamp looks like a no go . it's 4k and the box , if it's the same size as the evo , is too f****** big

John

 

just to revive this thread now that I've new speakers, the epos es22s, which have as default the facility to tri-amp. "The midrange driver crosses over mechanically and is directly coupled to the power amplifier for maximum information retrieval and control. This makes the midband responsive, transparent and explicitly detailed. The bass driver and tweeter use single component networks solely to fine tune their integration with the midrange unit." http://www.epos-acoustics.com/old_products/es22.htm

"The Epos ES22's have a three way crossover and sound their best when each speaker unit is driven with three separate power amps, thus six amplifiers are needed to for best results." "When that big bass signal appears on the left woofer, the rest of the system carries on as if nothing has happened this is because each component is running on its own power supply.** Bi-amping won't make your system any louder but it will reproduce the sound more accurately and you will hear a marked decrease in the inherent distortion between mid to high frequencies and low frequencies, thus resulting in super sonic reproduction with a much more defined and dynamic frequency range"
http://www.arcticcorsair.f9.co.uk/audio/articles/amplifiers.html

At present, I am using a 'bridge' across the three sockets for each speaker, and am neither bi-, nor tri-amping.

Do folk stand by their 'no to bi/tri' arguments as applied to this speaker config. (rather than to the earlier JMLab Electra config., which incidentally the JMLab rep I met up with thought was better driven in single rather than bi mode, and advised me to do the direct link of cones inside the box - which I did to good effect)?

(btw, I accept that 2x60w may not be enough, and that I prob. should have tried the Evo by now.)
I am given to understand that this is also the 'active' argument, but although also followed in Pro use, the logic there is ease of replacement of the part that blows-up/breaks-down.

 

I've tried all that biwiring/biamping/monoblocking lark.

There was always something not quite right about the overall sound.



Now use an integrated (Sugden) with speakers single wired.
Much better sound.



My advice now is to get a decent integrated...
Spend any change on vinyl/CD's.

 

Please note that if you biamp with two 60W amps that output is still 60W for the same input, not 120W as your question implies. (IOW, the gain of each amp from input to output is still the same, usually around 28dB and each output stage runs out of swing at just the same time).