Since a competent active system that uses all available degrees of freedom can exactly (in ALL details, including parasitics and what have you) emulate any passive speaker-level circuitry, your statement is not true.
Point is that 99% of the people (including industry professionals) associate "active" with any kind of line-level cross-over and response shaping (or response shaping alone, for full-range drivers) driving standard voltage output amplifiers driving transducers directly.
While doing OK this way and probably already better than passive, this still misses a main point of active as it does NOT use all the degrees of freedom that are available, notably the possibility to use arbitrary output impedance, motional feedback, and the use of specifically designed drivers that are not constrained by the need for pretty flat transfer with standard voltage drive.
Quite obviously a full-blown active system can hardly be as cost-efficient as a passive speaker + amp and of course there are passive speaker that are much better that active ones....
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depends on design
actually, I think you can build very good active speakers with cheap electronic
but if your passive design involves big inductors, those have to be very good quality, and will never be cheap
I think i have a pretty good idea what Michael is talking about. If that is the case you would have to have sensors on the drivers feeding back to the cross-over, and i doubt it would be able to accurately track what the passive does inherently and very elegantly.
dave
Remlab.
The tweeter we use is a planar magnetic. It has quite low distortion, but more important it's very very light, so it stores no kinetic energy under movement, and thus has no resonance, in this respect it's more than 30 times better than any conventional design. where you have mass/spring issues to deal with.
Reason I react to this active VS passive debate is the simple fact that drivers change under amplitude and if drivers are treated separately (as in active) they will change individually with different SPL making the picture nervous and fragile. With a passive (current shunt type x-over) these dynamic changes are reflected into the system as a whole thus maintaining the integrity of the system and keeping the composure of the (sound) picture stable.
One very important parameter the alters under amplitude is inductance..that differs with position of the VC. and Back EMF that is different for different amplitudes. those changes need to be reflected into the other drivers of the system, to maintain the systems composure.
Back EMf makes amplifiers sound different, and if this difference only happen in the bass and is not reflected into the mids and highs the system becomes detached.
Active is for high efficiency not for high-fidelity.
The tweeter we use is a planar magnetic. It has quite low distortion, but more important it's very very light, so it stores no kinetic energy under movement, and thus has no resonance, in this respect it's more than 30 times better than any conventional design. where you have mass/spring issues to deal with.
Reason I react to this active VS passive debate is the simple fact that drivers change under amplitude and if drivers are treated separately (as in active) they will change individually with different SPL making the picture nervous and fragile. With a passive (current shunt type x-over) these dynamic changes are reflected into the system as a whole thus maintaining the integrity of the system and keeping the composure of the (sound) picture stable.
One very important parameter the alters under amplitude is inductance..that differs with position of the VC. and Back EMF that is different for different amplitudes. those changes need to be reflected into the other drivers of the system, to maintain the systems composure.
Back EMf makes amplifiers sound different, and if this difference only happen in the bass and is not reflected into the mids and highs the system becomes detached.
Active is for high efficiency not for high-fidelity.
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Hey, VC heating, back-EMF and Le(x) can be made completely irrelevant with current drive instead of trying to live with it, that's one of the main reasons I use it within the passband of a driver. Except for off-the-shelf woofers down low around resonance, where some electrical damping is needed. With two identical woofers a control loop can be set-up that compensates VC heating and resultant change of electrical damping and gain.
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Sounds like some of the magic I was asking about earlier. It sounds like a good story, but is this behaviour something you can predict and model? Do all amplifiers sound different in the same way when subjected to back EMF? Is the net result of this intentional intermodulation between drivers a higher level of distortion that simply changes less in proportional terms than in an active system?
So you can compensate for the level-dependent (increasing..) distortion in drivers by introducing an other type of distortion? Audiophiles in general may buy that sort of quasi-technical nonsense, but I don't.
Well maybe you can - with some luck - compensate for a driver that does not have the same frequency response at different levels. That of course will require that crossover parts also saturate and change their values with different input levels.
But on the other hand, I would stay away from such drivers and crossover parts....
Copper top.. you got it... changes in one area should be reflected in the other areas, this is simply not possible with active...If you think of it, how many top systems are active...??
It may be possible to get active to work in the base region, but even that is very difficult just try to add a sub to a good quality 2 way. 99 of a 100 times it sounds slow, detached and out of sync with the music...
StigErik point me to a driver that does not change parameters with SPL.
That was basically the sole reason for entering into building our own mid/bass drivers at Raidho.
It may be possible to get active to work in the base region, but even that is very difficult just try to add a sub to a good quality 2 way. 99 of a 100 times it sounds slow, detached and out of sync with the music...
StigErik point me to a driver that does not change parameters with SPL.
That was basically the sole reason for entering into building our own mid/bass drivers at Raidho.
Practically all of them.
To wit: ATC, PMC, ME Geithain, Neumann/Klein&Hummel, Quested Audio, Barefoot Sound etc.
You know the ones which are chosen by the people who actually get to compare the recording to the actual performance.
Passive is better than active – no doubt !
…because this is a perfect situation for the industry, the dealer, the magazines and the audiophile.
The industry is able to sell new better amplifiers, speakers and certainly cables.
Next year’s cable has another colour or new type of wood to block bad digital noise and the next year’s power amplifier has new wrapping with some kind of magical alloy that cures room resonances etc.
Each year the dealer will be able to present something new that the audiophile will gladly come around for a demo and the dealer will probably sell some of the old technology with new wrapping.
The magazines will easily compare and measure the new amplifier and speaker and they can put some newly developed phrases on the newly developed magical cables.
The audiophile - the true one (audiophile) has to be able to test different combinations of cables, loudspeakers and power amplifier – so no doubt that passive is better.
Whereas an active setup is not at all straight forward… The manufacturer has to make the whole system as no speaker is prepared for active drive, no standard crossover will fit all, cables suddenly make much less sense and it’s much more complicated to persuade the customer to buy the multi thousand dollar expensive power amplifier that “cures all problems” x 2, 3 or 4. The dealer has no knowledge of measuring and setting up the system and the audiophile is deprived of the simple opportunity to compare cables, speakers and power amplifiers. How do the magazines test this bulky complex active system and how do they compare two different system that can be changed within seconds and did they at all make the right changes – oh no they might fail when changing a parameter !
It simply does not make any sense to use active amplification to change this perfect situation. Everybody is happy.
Regards,
Robert GS
…the debate from a practical angle, but I am not practical and I love the opportunities that active offers and always will do
…because this is a perfect situation for the industry, the dealer, the magazines and the audiophile.
The industry is able to sell new better amplifiers, speakers and certainly cables.
Next year’s cable has another colour or new type of wood to block bad digital noise and the next year’s power amplifier has new wrapping with some kind of magical alloy that cures room resonances etc.
Each year the dealer will be able to present something new that the audiophile will gladly come around for a demo and the dealer will probably sell some of the old technology with new wrapping.
The magazines will easily compare and measure the new amplifier and speaker and they can put some newly developed phrases on the newly developed magical cables.
The audiophile - the true one (audiophile) has to be able to test different combinations of cables, loudspeakers and power amplifier – so no doubt that passive is better.
Whereas an active setup is not at all straight forward… The manufacturer has to make the whole system as no speaker is prepared for active drive, no standard crossover will fit all, cables suddenly make much less sense and it’s much more complicated to persuade the customer to buy the multi thousand dollar expensive power amplifier that “cures all problems” x 2, 3 or 4. The dealer has no knowledge of measuring and setting up the system and the audiophile is deprived of the simple opportunity to compare cables, speakers and power amplifiers. How do the magazines test this bulky complex active system and how do they compare two different system that can be changed within seconds and did they at all make the right changes – oh no they might fail when changing a parameter !
It simply does not make any sense to use active amplification to change this perfect situation. Everybody is happy.
Regards,
Robert GS
…the debate from a practical angle, but I am not practical and I love the opportunities that active offers and always will do
So you've listened to 100 good quality sub/sat systems, and have found only one where the two integrate nicely?
Do share some details of your obviously extensive tests, including how you set the crossover up for each system, room placement of the loudspeakers, etc.
Cheers
Chris
OK I stop.. can't get into stupid arguments. I just stating my experience and also some of the clearly obvious reasons. seems like lots of religion in the, and that debate is not for me..
Robert do you really believe what you just wrote... I mean if ative was really superior don't you think that high end speakers that really aim for high performance would go down that route. I know I would, but these dynamic changing parameters are just too challenging for rigid active structures,
THe picture you paint of an industry, that has a sort of agreement on preserving certain system structures is just out of the blue.
Things will change wireless will be more, maybe even wireless speakers with built in amps driven directly from Ipad like devices, steamed data ect... But even that speaker will most probably have a passive crossover for all or most of the network..
Robert do you really believe what you just wrote... I mean if ative was really superior don't you think that high end speakers that really aim for high performance would go down that route. I know I would, but these dynamic changing parameters are just too challenging for rigid active structures,
THe picture you paint of an industry, that has a sort of agreement on preserving certain system structures is just out of the blue.
Things will change wireless will be more, maybe even wireless speakers with built in amps driven directly from Ipad like devices, steamed data ect... But even that speaker will most probably have a passive crossover for all or most of the network..
I absolutely believe what he wrote. Never discount the influence of tradition and fashion- the goal of a high end speaker manufacturer (as opposed to a hobbyist) is to sell stuff, and if the buyers of expensive speakers love entertaining themselves by swapping components and wires, they won't be happy if this opportunity is taken away from them.
The high end fashion audio market has rejected excellent active systems again and again. Gordon Holt wrote an annoyed editorial about this perhaps 30 years ago and it's just as true today.
Good engineering starts with a well-defined target and uses the best means to achieve that target. This is why my own speakers, which are totally noncommercial, use a mix of passive and active. If I were to design commercial speakers for the high end market, I would only use passive, not because it's the "best" from an engineering perspective, but because I could sell it...
When the answer for "why do people do X instead of Y for commercial equipment?" is "fashion," then that's the answer I'll give.
When the answer for "why do people do X instead of Y for commercial equipment?" is "fashion," then that's the answer I'll give.
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