This is a two-parter .. THis is the second part ..It is most relevant to the discussion at hand
The discussion has laready started on the Wilson Bi-amping thread I believe it would be more interesting to openit up to multi-amping in general.
I have been researching ways to have a good system in a challenging environement. I will not just throw money at it and expect great results . The new room will have some strong limits and challenges. I looked at Digital Room Correction and stumble upon crossovers and their design. Passive ,analog crossovers may yet be the Achilles Heel of Audio is crossover design. I began to understand that passive analog crossover are a very poor approximation of a transparent device… Populating a passive analog crossover with the best you’re your money can buy and it will remain a very poor approximation of the desired transfer function: Most drivers wok in a very small frequency range, most if not all (I know, that aside from a few ESL there exist some “full range” drivers they have a strong following but once you listen to these, you will understand why they are not so widespread) . Back to drivers. You need to send a band of frequency to a speaker drivers within its operating range. Low frequencies require large driver with large excursion , middle just middle of everything and high frequencies require smaller drivers. SO in many speakers you have at least two drivers and that is where crossovers become a problem because of so much loss in the crossovers themselves. In speaker designs the middle frequency and high frequency drivers are usually of high sensitivity easily in the mid to upper 90’s while the low frequency drivers are often much less… the filtering often requires that the output match and for that resistors are used simply to waste the power coming to the driver.. This is often done BY DESIGN and most speakers revert to that in their network.. Imagine this you just put a component with a potential for distortion just to dissipate/waste several of the expensive watts coming to it!! That what is done in many speakers and in some designs for example first order it is almost systematic, thus the often poor sensitivity of first order speakers (there are other reasons) … In addition these crossovers segment present strange and varying loads to the amplifiers and you end up with what we have been living for a long time: passive crossovers.
Active crossovers be they analog or digital do not suffer from this waste problems their job is simply to steer the frequencies to the various amplifiers not the drivers themselves and the amplifiers do see a limited band of frequencies thus able to function sending their full power potential to their connected drivers. Some of the better speakers out there force you in a bi-amping of sort , although most people don’t see it that way. The Genesis 1 , 200 and up to the 5.3 , the VR 9 and 11, The Evolution Acoustics , The Arrakis 2 have an amplifier just driving the bass and your amp drive the rest. Yet, ask anyone who has experienced speakers with active bass and they will tell you that the mains amplifier bass “flavor” continue to be apparent and believe this can be done blind… No stressing and straining and simply state that “the soundstage went wider” upon seeing the amp change ..No! Clear quick and blind ,one will hear the bass flavor of an amplifier.
Which brings me to multi-amping. It seems to me that the ideal should be multi-amping. An amplifier for each frequency range. One foe the bass driver, another for the mid and one for the HF.. In the middle a n active crossover. I prefer digital because then an entire universe opens up to the audiophile. Phase (Timing) correction, speaker correction, room correction can be done in a way that no analog can dream of and the most interesting thing is that this can be married with a full analog set-up. The best example and a system which from the opinion of those who have heard it is one of the best out there is that of Marty here at the WBF. I believe he has VTL Pre, VTL amp Pipe Dreams speakers and Two JL Audio Gotham as woofers for his system .. he also uses a TT and ALL his music goes through his TaCT and some of the crossover duties are also handled by the TaCT .. I could be mistaken… JackD201 has gone a different route his system is however tri-amped.. with the VR-9 .. The subwoofer/bass is handled by the VR amplifier but the mid-bass is driven by its on amplifier and he uses another amplifier for the upper range.. I am dying t hear his system and I am certain it sounds better than not multi-amped… I don’t know too many other persons doing the same here aside from those who have gone fully active with active speakers (Audioguy and Phelonious Phonk). The knock on Active crossovers that they are not “transparent” The reality is that they are more transparent and by order of magnitude than passive crossovers due in some part to the smaller signals going through them thus less loss and by the active segment which affords some multiplication of values… They also allow better approximation of the mathematical transfer functions.
My position is that the digital crossovers approach allows the best of all possible worlds. The mathematical functions can be replicated with a degree of precision impossible in analog. You want 32 db/oct slope but phase coherence .. No problem.. You can’t do that with analog. You want ultra-steep 300db/oct filter.. Done!.. Virtually impossible to have such steep slope with analog. You want to implement a notch filtering of that pesky ceramic resonance at 6.3 kHz? Done! You want those break ups at the low-end taken care of ..? Done too.. You want to correct for abnormal room behavior in the modal range .. Piece of cake .. Just press Enter And this can be done with most speakers. Allowing the owner to use an active crossover is an interesting option, one that Believe one bring higher performance to already superlative systems. An example. Let’s take the superlative X-2 and let’s suppose it is multi-amped, then mid-range can be a SET , bass a seriously powerful amp and up there a tube with extension .. Care would have to be taken to match the flavors of all the amplifiers but I am willing to bet such a system superior to an all passive set-up, even if one were to go the route of those now available mega expensive and mega powerful amplifiers… whose expensive watts will likely be dissipated in the resistors of the passive crossover.. It doesn’t necessarily have to be more expensive but even if it were or even if one were to go bi-amp with the upper modules driven by the SET and the low by a stout amplifier SS or Tubes (at least 300 watts/chi) and then supplement this with a trio of sub.. You would have a scary good superlative system capable of the kind of instantaneous SPL one only hears in real life .. while preserving ALL the qualities of this (or other) already superlative speaker system.. What do you think people.. your takes on this?
The discussion has laready started on the Wilson Bi-amping thread I believe it would be more interesting to openit up to multi-amping in general.
I have been researching ways to have a good system in a challenging environement. I will not just throw money at it and expect great results . The new room will have some strong limits and challenges. I looked at Digital Room Correction and stumble upon crossovers and their design. Passive ,analog crossovers may yet be the Achilles Heel of Audio is crossover design. I began to understand that passive analog crossover are a very poor approximation of a transparent device… Populating a passive analog crossover with the best you’re your money can buy and it will remain a very poor approximation of the desired transfer function: Most drivers wok in a very small frequency range, most if not all (I know, that aside from a few ESL there exist some “full range” drivers they have a strong following but once you listen to these, you will understand why they are not so widespread) . Back to drivers. You need to send a band of frequency to a speaker drivers within its operating range. Low frequencies require large driver with large excursion , middle just middle of everything and high frequencies require smaller drivers. SO in many speakers you have at least two drivers and that is where crossovers become a problem because of so much loss in the crossovers themselves. In speaker designs the middle frequency and high frequency drivers are usually of high sensitivity easily in the mid to upper 90’s while the low frequency drivers are often much less… the filtering often requires that the output match and for that resistors are used simply to waste the power coming to the driver.. This is often done BY DESIGN and most speakers revert to that in their network.. Imagine this you just put a component with a potential for distortion just to dissipate/waste several of the expensive watts coming to it!! That what is done in many speakers and in some designs for example first order it is almost systematic, thus the often poor sensitivity of first order speakers (there are other reasons) … In addition these crossovers segment present strange and varying loads to the amplifiers and you end up with what we have been living for a long time: passive crossovers.
Active crossovers be they analog or digital do not suffer from this waste problems their job is simply to steer the frequencies to the various amplifiers not the drivers themselves and the amplifiers do see a limited band of frequencies thus able to function sending their full power potential to their connected drivers. Some of the better speakers out there force you in a bi-amping of sort , although most people don’t see it that way. The Genesis 1 , 200 and up to the 5.3 , the VR 9 and 11, The Evolution Acoustics , The Arrakis 2 have an amplifier just driving the bass and your amp drive the rest. Yet, ask anyone who has experienced speakers with active bass and they will tell you that the mains amplifier bass “flavor” continue to be apparent and believe this can be done blind… No stressing and straining and simply state that “the soundstage went wider” upon seeing the amp change ..No! Clear quick and blind ,one will hear the bass flavor of an amplifier.
Which brings me to multi-amping. It seems to me that the ideal should be multi-amping. An amplifier for each frequency range. One foe the bass driver, another for the mid and one for the HF.. In the middle a n active crossover. I prefer digital because then an entire universe opens up to the audiophile. Phase (Timing) correction, speaker correction, room correction can be done in a way that no analog can dream of and the most interesting thing is that this can be married with a full analog set-up. The best example and a system which from the opinion of those who have heard it is one of the best out there is that of Marty here at the WBF. I believe he has VTL Pre, VTL amp Pipe Dreams speakers and Two JL Audio Gotham as woofers for his system .. he also uses a TT and ALL his music goes through his TaCT and some of the crossover duties are also handled by the TaCT .. I could be mistaken… JackD201 has gone a different route his system is however tri-amped.. with the VR-9 .. The subwoofer/bass is handled by the VR amplifier but the mid-bass is driven by its on amplifier and he uses another amplifier for the upper range.. I am dying t hear his system and I am certain it sounds better than not multi-amped… I don’t know too many other persons doing the same here aside from those who have gone fully active with active speakers (Audioguy and Phelonious Phonk). The knock on Active crossovers that they are not “transparent” The reality is that they are more transparent and by order of magnitude than passive crossovers due in some part to the smaller signals going through them thus less loss and by the active segment which affords some multiplication of values… They also allow better approximation of the mathematical transfer functions.
My position is that the digital crossovers approach allows the best of all possible worlds. The mathematical functions can be replicated with a degree of precision impossible in analog. You want 32 db/oct slope but phase coherence .. No problem.. You can’t do that with analog. You want ultra-steep 300db/oct filter.. Done!.. Virtually impossible to have such steep slope with analog. You want to implement a notch filtering of that pesky ceramic resonance at 6.3 kHz? Done! You want those break ups at the low-end taken care of ..? Done too.. You want to correct for abnormal room behavior in the modal range .. Piece of cake .. Just press Enter And this can be done with most speakers. Allowing the owner to use an active crossover is an interesting option, one that Believe one bring higher performance to already superlative systems. An example. Let’s take the superlative X-2 and let’s suppose it is multi-amped, then mid-range can be a SET , bass a seriously powerful amp and up there a tube with extension .. Care would have to be taken to match the flavors of all the amplifiers but I am willing to bet such a system superior to an all passive set-up, even if one were to go the route of those now available mega expensive and mega powerful amplifiers… whose expensive watts will likely be dissipated in the resistors of the passive crossover.. It doesn’t necessarily have to be more expensive but even if it were or even if one were to go bi-amp with the upper modules driven by the SET and the low by a stout amplifier SS or Tubes (at least 300 watts/chi) and then supplement this with a trio of sub.. You would have a scary good superlative system capable of the kind of instantaneous SPL one only hears in real life .. while preserving ALL the qualities of this (or other) already superlative speaker system.. What do you think people.. your takes on this?