Is Bi - amping worth the trouble?


Hello all...

I'm on the fence with the thought of bi amping. A big part of me wants to go ahead with it... the 'wallet' part says "Not so fast".

There should be lots of folks who've biamped speakers before... When it was all said and done, "Was it worth the time and expense?"

I'm inclinded to add a tube amp for the upper end of my VR4 JR's ... or any other speakers for that matter... though in any case and reardless the speakers, tube amp on top, and SS on the bottom.

...and then there's the thought of keeping two dissimilarly powered amps matched at the same volume level... and the added IC's, PC, and stand... it does seem to add up.

... and at this point, I'm thinking BAT to keep things all the same... and am not sure there, wether even that matters too much...

I sure do appreciate the input.
blindjim
FWIW, you cannot in fact say there is a "consensus" here or in audio in general that bi-amping is simply superior (active or passive).

Bi-amping has one theoretical disadvantage: the loss of coherency due to mixing two different amps with their unique sonic characteristics. There will always be freq-overlap of the two amps with any crossover. This is assuming different amps top and bottom, but as has been pointing out, that's the only way to do it unless you're just down on power.

I'm not saying that bi-amping isn't better in nine out of ten situations (though I'm not saying it is), just that you can't make a blanket that it's always better with this potential/theoretical weakness (which many feel is very real in practice).

Well, I'm certainly impressed. haven't done anything yet, but still given the level of informative thoughts and experiences that have presented themselves herein... I am way impressed. As said above, and with no attrmpt to have the last word or bring a hlat to this strem of thought, formulating or making cohesive the question to the responses, the answer thus far needs be dependant upon waht a person views as "trouble". If I may be so bold... and I will.

Apparently one does not escape subjectivity. Be it in practice or methodology. Equating the value or difference between two parts derives the sum of it. What is the level achieved? What is the effort involved? Was there even one summary dismissal of the project? I don't recall it. I do recall some explicit recounts of knowledgeable folks, passionate about audio who were satisfied, ultimately, with the end product. I recall unselfishly how many told of the areas to be aware of, the pitfalls and prerequisites, and the proceedures to reach a proper end with either path, be it active, or passive bi-amplification.

I get the overall feeling at this 'juncture' (if I can quote a former chief of staff), that it's a viable task. One that the results have outweighed the sweat and expense along the way. For me I am sold on the notion to fulfill both a desire and a dream. Though formerly struck near dumb by the avalanche of steps, and the coincidental expense of them to boot, I have recovered sufficiently to grasp the reins and once more move towards that end. (…can’t you just hear Ray Charles in the background softly doing America The beautiful?).

So I’d say just now the posts here say resoundingly, “You bet cha!” But there’s more to it than just buying a second amp and some more wires…. Perhaps. The keys being as I understand them thus far:

Matching the gain of both amps
Limiting amplifier bandwidth for dynamic improvement in the loudspeakers performance… given their particular applications.
Addressing the networks of the loudspeaker dependant upon the choice of an active bi-amping application.
Buying more peripherals.
Buying lots more peripherals.

….not a problem. I thought I was seeing a light at the end of the tunnel… then I thought it was a train. The light is much dimmer now. This tunnel has a curve in it! Fine. I’m good. I’m also looking forward to the whole shooting match. Because from what I’ve seen here, bi-amping is worth it. For regardless the results, my inventory of equipment willhave increased and there will be lots more to play with from time to time. How can you not see that as a plus? (…well there’s that buying it all, part, I guess).
Let me try and put some order (into my thoughts at least) on biamping:

As seen before there are various methods for biamping with different results:

1:Dual-amp biwire (nice new term) which is achieved without any freq, limitation on both amps, both amps "amplify the full signal" These method uses forcibly the speakers internal Xover.

1a-Dual-amp biwire with same amps being paralel or series would be just more of the same, yes more power supplies so also more dynamics and more power, same sound. If it is two tube amps the bass will still be a little "undefiend" if its two SS amps the top will be "grainy" (you can change these adjectives as you please...undefined and grainy are just MHO)
*No gain (volume) matching devices needed.
*Use speakers internal Xover

1b-Dual-amp biwire with different amps where you get the sonic benefits and performance of different type of amps; for example: Tubes on top and SS on bottom.
*Gain (volume) matching devices needed.
*Use speakers internal Xover

2- Passive Simple Biamping, Lets agree that for this you need to limit the freq. going into at least one amp.
*These method would still need the speakers internal XOver
* High pass, to avoid this amp to overwork with bass freq.
*Low pass avoiding mid and higher freq. on the amp. (Big SS amps don’t really need to get rid of highs)
*These Xover should be Passive at Line Level before the amps.
*Gain (volume) matching devices needed

3- Active Simple Biamping, Limit freq. going into at least one amp.
If you have satellite monitors and a subwoofer, this could be active simple biamping, since you are using a dedicated bass amp inside the subwoofer. You can also use an EQ for the bass amp which would act like low pass and add a little punch and extension on the lower freq. (nice!)
*These method would still need the speakers internal Xover (because it is simple)
* High pass, to avoid this amp to overwork with bass freq.
*Low pass avoiding mid and higher freq. on the amp.
*These Xover should be Active at Line Level before the amps. Gain (volume) matching devices are usually built into the active Xover.

4- Extreme Biamping, Triamping etc.
*You will need one amp for each driver and there should be only wire going from each amp to the driver.
(An exemption to the rule could be tweeter which could have a passive Xover between amp and tweeter.)
*For this method you cannot use the Speakers internal Xover, It would not be recommended to use a “designer” speaker since there would really be no point to rip out the original “designer” Xover to play around. This method would be recommended for DIY speakers such as Lowther drivers with bass, Horn systems, Professional PA systems etc.
* Line level Xover can be Passive, Active or a Mix of them depending on Amp-Driver combination used.
*Gain (volume) matching devices needed
Jsadurn has got it very well summarized. I just don't agree with generalizing that ALL tube amps have loose bass and sweet highs, wheras ALL SS amps have great bass and harsh highs. There are amps that do everything right, for a given speaker, NOT because they are tube or SS. And there are amps that do many things wrong, again NOT because they are tube or SS. So, making a rule that the best way to bi-amp is to mix SS and tube amps is an over-simplification.
Warjarrett

If I made a generalization about the tilt of the posts it seemed prudent to me to do so. Waht with the wealth of info being jotted down to further the effort of bi amping. I recall few, if any detractors. However, I understand your point, I believe.

I would think it a given regardless of amp design, a specific speaker may be better mated with a particular amp. I also know from previous experiences there are indeed good and less than good amps solid or holllow state.

I envision the prospect of having both designs at least once, working together in a system. though until recently, I think one can generalize as to the more often than not sonic differences... from Solid to tubes, as more the statement of design archtecture, than perhaps if it's primarily one that employs "no tubes" or one that employs "some tubes". I suspect the recent infusion and growing popularity of HT seems to have changed the voicing of tube amps to a more, if not spot on, neutral cast, by mere demand. What with brand loyalty, and mixing present two channel systems into it a more neutral, faster, more dynamic sonic character of recent tube designs allows for that integration to be one with less disparity which previously existed between SS & tubes.. IMO.

I am not of that ilk. I prefer a touch towards the darker side of neutrality… Not a lot but surely some. Certainly more than I am experiencing with my current amp. The vk500 doesn’t have a brittle bone in it’s body, sonically. Great ease and a wealth of power. Quick and solid. As best I can tell, from top to bottom. An amp one can listen to with great pleasure and endlessly if so desired. I merely wish to add to it. Though I did think to simply add another vk500 during my first thoughts about this endeavor.

Then, what true gain would I have? I’d still not have the experience of both… tube and/or solid amps, in concert., or singularly the tube amp. I'm of a mind that there is a difference between the character of tubes vs. solid state, given just my experiences.

I enjoy now the warmth of what the vk5i, and a goodly bit of tube rolling have provided, but I see it as only half the way there. I just want the other half of it… whatever that may well be. I’ve not heard a great sampling of tube amps as of late but of those I have heard that I consider special, the SS amps in the same price ranges could not compete with the luster or character of the sound furnished by an all tube system. .. but of course, that’s just my little slice of investigating the far greater world of audio.. and try as I might, I have been unable to recreate the sound of an all tube system, though I am close in a couple respects, I can’t quite get it there. Consequently, without making a complete change I’m figuring to just add on. A tube amp for me just seems right somehow. IMO.
Well, in all honesty you might just be best off finding a more liquid sounding Preamp instead of neutral dark and punchy.. The bats are very good, but most of the stuff I listened to them with were on the more Damped sounding speakers like Dynaudio which mixed very well with the BAT tube sound... with the liver sounding speaker you have The VK 500 I don't think is your problem, maybe try a conrad johnson or Cary preamp with some tubey type tubes.. Mullards, Telefunken or something and see what happens. Then worry if bi-amping is a real need.
I'm with Undertow. I think bi-amping your existing system is basically "busy work". It will provide a change but you shouldn't look for an improvement commensurate with the trouble and expense required. After all, you really won't be changing anything. You will still have the same drivers, crossover, etc. The only thing you can achieve is more volume and you don't seem to need that.
Your money might be better spent on real change like a new listening chair.
Macrojack
that is funny. thanks. I have been giving a lot of thought to the chair lately. Just putting it off till I revamp the room. Making do with what's here, given the incredible prices of the furniture I have seen that I do like. You could get a nice amp for the price of the couch alone. so I've decided to settle for less costly a seating arragement. And rugs? My goodness!

For good or ill, my friend, this time next year ol' blindjim, is going to have two amps driving something. Probably be driving me nuts. A fella told me sometime back, as life improves, problems do not go away, all we can hope for is that the quality of them improves too.

I am also considering (passive) bi-amping B&W802Ds... Owning now two quite a big SS amps - Rotel RB-1090 and Parasound Halo A21, preamp Primare PRE30 (two pairs RCA output plus single pair XLR outputs), I wonder which configuration is appropriate: RB-1090 on woofer, while Halo A21 on mid/high terminals should be natural solution, given the power/watt capability (RB-1090 380Wpc, Halo A21 250Wpc). Some guys ephasized strong position of the "gain" factor of both power amps. I took a look at RB-1090 and Halo A21 specs, and not found any "gain" spec.

Guys, could anyone tell me something more about compatibility of RB-1090 and Halo A21 as pair of bi-amping SS powers?

BTW: I am building the new audio room these days, so not tested anything yet. B&W and Rotel brand new, received recently.
Zormi- Try to see bi-amping as a remedy. That is, something you apply in an attempt to overcome some shortcoming or failure in your system. You have brand new equipment ready to install in an unfinished room. Why not put it all together and see what you have before introducing change? You may not need or want to do anything at all.
Not all changes (mods) are improvements. And audio is not purely additive. More can be worse and less can be better.
Take your time and alter things gradually and, above all, one at a time. Fast changes make for slow progress and slow changes make for fast progress.
The only places where bi-amping is really useful are in powered speakers where the amps are onboard and dedicated to their assigned drivers OR in speaker systems specifically designed for use with an active crossover and multiple outboard amps. The rest of this stuff is just toyboy nonsense.
Hello Zormi,

Though I always recommend biamping I would agree that it is best to finish your room and listen to your new system enjoy each step of the way....
I am also finishing my audio room these days! and am also waiting to try new things I have a pair of subwoofers I want to try as a biamping alternative and probably a new better transport! But the first thing will be to listen at my system as it was when I took it apart.

Thanx for inputs guys,

It seems the best to try all options, step by step... And I would do so, surely. My main concern was the UNSPECIFIED (in specifications) gain factor of both power amps. I am curious can I derive somehow the gain factor basing calculation on other available specifications...

Halo A21 mated with Primare PRE30 achieved stunning results driving a pair 803S. I consider my new 802D as much more difficult task for the power amp - that's why a new RB-1090 reinforcement in my place.
Zormi

I'd say the 802D's eff is greater than the 803's eff... 92db vs. 89db (?)... so it would seem an easier load just by that account. I had several pairs of BW units and thought the Bi amp path with them a slam dunk. Seeing the above postings about the various paths to that end, tells me differently. I also spoke with the Tech support head honcho across the pond about impedances and such... BW does things a bit differently in how they measure things along those lines according to him. You may want to get in touch with him via the BW USA WEBSITE SUPPORT TAB. TO GET A BETTER UNDERSTANDING...

I do know of at least one tech rep for an entirely different company that was using a 60 wpc CJ tube amp to drive the 802N's, and he said he loved the sound.

Though what has been said about bi amping being a task to remedy a problem may well be sage advice... then directly afterwards is another take opposing the previous one. Finding out what one has first is a slam dunk common sense thing. Fashioning a system the way you want is your own choice. Always. In this thread alone, there is significant info for your task, and it's not the only resource. There are some quite worthy efforts posted here so I do hope you enjoy your pursuit!
Read the entire thread, still need advice from the pro's here.

Short and sweet...Running VR-4 Gen III's, Aesthetix Calypso, Parasound JC1's.

I may have the opportunity to purchase another pair of JC1's at a very reasonable price.
VSA does not discourage passive bi-amping using the speak's xover, in fact, Albert seems to encourage it. This may seem like total overkill to some, but I like my music to grab me by the throat and nuts at the same time.

So, four identical amps, vertically and passively bi-amping VR-4's.
Is it worth it, should I try it?
You are currently getting almost everything your speakers can provide. Someone suggested moving up in the VS line. I suggest moving beyond it. Both ideas are going to give you more future upgrade options than you will see by trying to squeeze your current speakers for the last two per cent they might have in them. Bi-amping your current speakers means driving into a cul de sac. The only way to go from there is back out.
Besides that, it's a little like putting a spoiler on your Neon.
Blindjim, I have the VR5 SE's and just finishid biamping them, I have a Vac Phi 110 driving the tops and a Spectron Musician III driving the bottoms. Was it worth it? Absolutely! I love the Vac amp but it just didn't have the bottom end I wanted.I bought the Spectron and tried it by itself with the 5's "great bass" but it couldn't touch the Vac in the mids and high's. One thing I noticed when running them seperate was that the Vac played a lot louder at the same volume setting, later checking gain I found the Vac to be about 10db louder.I put a pair of Rothwell 10db attenuators between the pre and the Vac and that seemed to solve the problem. Maybe I was lucky but I found no other problems and the system never sounded even close to what I have now.
The Vac will be louder cause you eliminated all that loss in crossover on the lows, and the fact you are not driving lows with it now at all, but the crossover itself was probably soaking up 50% plus of the power in the amps power supply, so its got a lot more headroom in reserve. Yeah biamping if done right with good speakers and amps can definatly have advantage's.
Why not put all the money In a ecxellent stereo amplifier, instead of several lesser units with signal degrading from external crossover units.

Mfontana
Good to hear. those 5's are way more sensitive than the 4JR's though, aren't they? that following post makes sense too... eliminating some path and resultant obstacles should have provided for more gain... I'll keep those rothwell attenuators in mind too.

Hiend2
that's a good question. Actually i'd like to have an idea of just how much a signal is degraded period. by anything... and just how much can a signal be degraded before it is audible? ...and are we sure that a signal is being degraded, in the first place? or is only X overs the culprit for signal degredation?

Personally, i think otherwise. if this tact has worth... the signal begins at a source. let's say a digital source. let's say the signal is at it's best after all the D/A conversion is done... that's the output terminals. then would cables play a part in signal degredation too? oK, how much?

I hear that term bandied about frequently. From personal experience, in cable applications, everytime a connection is employed in the signal path a resultant loss of approximately 3db occurrs. Depending upon the initial signal level, 3 db isn't much at all. minimally in regular setups, given the above... 12 to 18db loss is occurring. Now if there is loss, then isn't the signal being degraded? Loss equates to degredation. Distortion, now, there is perhaps a more apt term. i believe many confuse the one with the other... and use them interchangeably. then it would stand to reason a one piece unit without additional peripherals and connections 'should' (if comparably build quality is incorporated), be best. integrated units should take the lead... I think 'separates' are in that position, however.

All in all, there is no such thing as a perfect system or plan, if humans are involved. As to the above poster, 'perfectionist', I too am a perfectionist... with a poor track record... so I gave up on that path and decided to be extremely good, and most often, 'just above average', I can live with that quite easily. there is more time for listening, and enjoyment, and oh, yeah, there's that 'fun' aspect of it all too.
Perfectionist: Given the fact that you're using mono-blocks, you wouldn't be vertically or horizontally bi-amping. You would simply be bi-amping with mono-blocks.

Blindjim: How did you arrive at the figure of 3 dB? At radio frequencies, every connection added is a supposed .5 dB loss according to common teachings. In my experience, a good connection doesn't lose anywhere near that much. At audio frequencies, i'm quite certain that the loss is noticeably less.

Having said that, connection losses may not be linear in amplitude as frequency is varied. On top of that, other distortions may occur as a result of added connections. Obviously, the quality of connection will have a lot to do with how much loss is involved. The greater the variances between terminating impedances, the greater the loss and potential for increased distortion. Needless to say, part of "cable swapping" is a combo of all of the above, which partially explains some of the variable results we achieve in different systems.

I've often contemplated what would happen if one were to take a distortion analyzer and measure an entire system from source input cabling to speaker output cabling. After baselining the system as one normally runs it, one could then swap individual cables and re-run the same tests. I think that the comparative results would be very interesting to say the least. It would also be interesting to see how the system as it was would sound compared to the system as it measured lowest in distortion.

Obviously, one could conduct such testing component by component, swapping cables until the lowest distortion was achieved. From there, the next component and cable could be installed, taking the same approach. One could repeat this until the entire system had been pieced together using this approach.

Using this method, the cables would be acting as impedance matching transmission lines. Each cable would be fine tuned for the specific electrical interaction between the mating components that they joined together.

There's a LOT to think about on stuff like this. Quite honestly, i'm surprised that nobody has done anything like this and / or published research on this subject. Then again, most AF engineers don't think about cabling acting as a "transmission line". Could be why the subject has never been looked into that thoroughly.

Other than that, there are great sonic advantages to be had going "direct drive" i.e. no caps, resistors, inductors between the amp and speaker. Most of the guys messing with "full range" drivers know and realize this, but most of the "audiophile world" are clueless in this specific area. Sean
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"Why not put all the money In a ecxellent stereo amplifier, instead of several lesser units with signal degrading from external crossover units."

First of all it is my impression that there are no Excellent stereo amps, excellent would apply only to mono amps...
What would a lesser or excelent amp be?
An excellent amp with 8 tubes per side on push pull? Thats a lot of tubes, and they do sound like it...IMNSHO a pair of pushpull tubes is best smaller is better then.
Also you get more power supplies with 4 monoblocks that with one stereo amp. I have even seen diagrams (and almost tried one) of one amplifier with a power supply per stage of amplification....that would make it 8 power supplies against...well one.

What we are also trying to avoid is the internal Speaker Xover and use line level XO inside each amp....cool!!

Do Bi-amp
Quite honestly, i'm surprised that nobody has done anything like this
Sean, FM Acoustics does this -- but for tis own products.

As you note, the designer hasn't published anything on this.

BUT, if you buy a complete system from FM (i.e. electronics + cables), that whole transmission line is optimised.

You can even buy speakers (made by someone else ASAIK) similarly "optimised" for the FM amp + spkr wire used. HOWEVER, I understand that the recommended solution is active multiamping... of course, one can order the spkrs with a passive xover in which case the spkr cable supplied is different (obviously).

So, the transmission line is purportedly optimised starting at the source output cable. Since FM's preamps allow some variability in their input impedance, this line can be tweaked soemwhat further upstream.

One snag is, the wires must be specific in lengths (apparently a small variability is OK). Another is the cost -- $~+10-15k per component: this may not look ruinous for some, but for a vinyl addict doing the simple maths, it adds up: Pre + phono+power amp = $+~40k. The cost of cables is minimal apparently:)
Oh yes, I forgot: you also need spkrs...

Oh yes: I actually listened to such a system, vinyl source -- with different spkrs. Admittedly, impressive, very impressive.
Getting in a little late on this one, and, I have not read every thread in response so apologies in advance for any redundancy.

I am a big believer in byamping, have been for quite some time, in my opinion, it must be done using an active crossover. I have tried using a passive crossover and I think the gains are not worth the expense. It is quite a bit more expensive going with an active crossover over a passive crossover. You will need two amps, two sets of interconnect, three power cords (one for the mid/base amp, one for the tweeter amp and one for the crossover), an active crossover (all active crossovers have gain controls for the top and bottom, at least I have not seen one without) and two sets of speaker cable. The results are quite impressive. Going in this direction one can than pick amps that suit his/her taste. SET on the top for the sweetness of a SET, SS on the bottom for the dynamics, weight and overall slam, or SET on the top and SET on the bottom, etc, etc.

When using an active crossover you will have to run your speaker cable from your outboard crossover directly to the individual drivers of the speaker. You will be bypassing the internal crossover within the speaker. You can't just hook up to the binding posts on the back of your speakers because you would not be bypassing the internal crossover.

I have found, as so many have referred to the blacks, the blacks are blacker, and the noise floor is lowered beyond belief. Each artist is positioned and stands alone without competition from others or movement. Each artist has his/her space; even on coral pieces there is depth and width without haze. The highs are so clear, a brush on a snare, one can count the number of bristles, obviously an exaggeration but I can hear various bristles making contact, shocking.

I am sure that there are many who will say the expense is not worth the return and to many that is true. For me, I will not be going back to a single amp to reproduce the whole frequency range running through a passive internal crossover anytime soon. Good luck with whatever you decide to do…………Bob
Bmotorcycle: This is one of those things that people won't / can't understand until they experience it for themselves. After doing that, they can't believe they wasted all of that time before stumbling upon this "aural revelation". As i've called it before, "direct drive" i.e. amplifier to speaker cable directly to the raw speaker driver is the real deal. Sean
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10-25-06: Sean
Perfectionist: Given the fact that you're using mono-blocks, you wouldn't be vertically or horizontally bi-amping. You would simply be bi-amping with mono-blocks.

Hmm, I guess I'm not fully understanding then. But I decided to pass on it anyway. I'm very happy with my system and don't want to screw it up. But I am patiently awaiting the arrival of an XPS2 to compliment my CDX2 :-)
Sean, I was one of the doubters for 30+ years. A recording engineer as well as a tube designer friend of mine kept hounding me to do nothing more than to try bi-amping. About two years ago I get a care package from him including an active crossover by his design and a highly modified 2A3 amp also by his design. Well, needless to say he has not seen the crossover or the amp for two years, I did pay him for them of course. Since than, I have added a true ribbon tweeter and again the addition was astounding, I will never go back to a conventional cone drive for the top.

I guess what continues to astound me, every time I added or changed a component and there was a positive improvement, after several weeks or maybe several months that improvement kind of just became the status Que. It has been 2+ years since I have bi-amped and the system continues to just amaze me. Before I bi-amped I would love to read while the stereo was on, now I have a hard time doing that, I just sit with a big smile and totally get involved with the music. I know it sounds kind of over the top but until you have tried it you may never know what I am talking about. The other side benefit is I am not always looking for that next fix, although I did just buy an 845 amp for the mid/base. More of my money is now spent on software. Sorry for the ramblings but I am a real proponent of bi-amping only if one uses an active crossover................Bob
I agree about passive vs actice bi-amping. The only time that i think passive bi-amping is worth the added cost is if the speakers are a very tough load and / or extreme volumes are required. Obviously, i would prefer to do so using an active crossover, but in some cases, that just isn't feasible. Increasing the headroom on such a system can make for a noticeable difference, but in such cases, you really need GOBS of power to overcome that type of handicap.

On the other hand, going active with "direct drive" sounds better under most any circumstance that i can think of. Sean
sean
...from experience. the signal loss may well be less than -3db occassionally... but as a rule of thumb, it's a safe bet to figure on -3db.... and as I said, "... in cable installations" ... referring to loss, and equating it to degredation... you must have missed that bit... I try to stay on point to answer the question or make a point.
Blindjim -- you've measured that ~3dB loss, in what? Or is it an overall, ball-park figure in resulting spl?
I'm curious, thanks.
Blindjim: -3dB is equivalent to a loss of 50% of the signal, which would not only alter the amplitude, but also the quality of the signal in most cases. I'm not trying to pick on you, but i find that figure to be way out of line to say the least. If someone were to latch onto that figure and use it as a point of reference, it may end up skewing their results or calculations. As such, i questioned this for sake of clarity as others may refer to this thread as point of reference in the Agon archives.

My own experience dictates a loss of appr .1 dB for a good quality connection that maintains similar mating impedances. The more that the mating impedances differ from one another, and the poorer the surface contact between them, the higher the losses involved. From my experience, a 50% drop ( -3dB ) in signal would require one helluva bad connection ( limited clean contact area ) between drastically different mating impedances. Sean
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Gain or loss of signal "strength" is measured in decibels, Do not confuse signal strength with sound pressure levels. there is more than one way to look at things. I was talking about the post alluding to signal degredation... how one could confuse signal loss or distortion and see it as sound pressure level indications, is beyond me.

Don't worry, Sean, You can't pick on me... especially if you and I are not talking about the same thing... and little of this aside has anything to do with the thrust of the notion as to wether or not bi amping is worth it I would think. Decibels are used to measure more than simple sound levels. Just a reminder for the more pedantic.

All I said, in my previous follow up, was I do not believe the addition of more amplifiers and the required peripherals will degrade the sound, or the signal to the extent that it is diffused or distorted. were that the case, ONLY the shortest path for the signal should ever be pursued. hence, with that sort of thinking, 'seperates' would not truly the best approach.... this is not the apparent case however as the largest majority of systems are comprised of separates.

So, it should stand to reason, the addition of more than one amp to develop a signal, should not, in and of itself, be seen as detraction from the bi amping path, or in any fashion provide an inheirent issue for signal improprieities. there's bigger fish to fry with adding amps than the worry of signal loss.

Hope that helps.
Blindjim: Signal strength / drive levels and SPL's are directly correlated in an audio system, albeit at a non-linear rate. This has to do with losses through-out the chain, mostly within the speakers. Most all of these losses are easily measured ( or at least approximated ) if one has the know-how and proper test equipment.

Having said that, the figures that i quoted were pertaining to actual line level measurements, not spl measurements. Since your reply was of a generic nature, i'm not certain if you were responding to Gregm as an individual, myself as an individual or both of us simultaneously. Obviously, we can't discuss the same subject if the subject being discussed and responded to is not clear. There is no body language to be interpreted over the net and we can't read your mind as to who you are talking to or where a specific comment was aimed at. As such, it helps to segment or identify who / what a specific reply is aimed at.

I don't think that anyone responding to your last few comments was being pedantic, so much as trying to figure out how and where you arrived at the figures that you proclaimed to be accurate. I'll have to assume that you avoided clarifying the issue for specific reasons and let it go.

Other than that, i hope that this thread has given you some insight as to the many variables involved. Given your last response, it would appear that you're now answering your own questions, so i guess we're done here. Toodles.... Sean
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Why don't you just bi-wire?? It's easier and well worth the effort. Use Anati-Cables - very cheap and excellent.
Sean.
"We are done here" ??

I was done some time ago. In fact, I believe anything of note was entered way back and certainly before your posts to the thread. I am relieved however, that you have taken it upon yourself to culminate things so cavileir like, though...

it's a sure bet you can not read minds. had you been able to you would have realized my choice of words was not pointed at yourself. Merely a generic and I thought, somewhat humorous ment regarding the more nit pickyish of us. If you feel it pertains to yourself, then, perhaps it does... though it was unintentionally and ambiguously aimed, and truth be told, of all the Audio nuts out there, (myself included), it is apt in any case.

You take things to much to heart Sean... get some thicker skin, friend. I bear you no ill will. Reading my follow up I thought would have been explanation enough... Whomever it was that asked about the SPL meter I used... THAT was to whom I was relating. I saw no need to clarify further, I should have. My PC wasn’t reading the page properly. I’ll be more careful next time. It’s not my desire to be consciously injurious.