My perception of active systems (from my own experiments, and having heard various hyper-expensive actives and passives at a show) is that they are more 'linear' in the sense that they don't change character dependent on volume as much as passives. This thread has mainly been concerned with the accuracy of the frequency and phase response, but I think what I am talking about is independent of this; I am reasonably persuaded that our ears can compensate for inaccurate frequency/phase response.
My perception is that passives begin to sound strained at high volume, while the actives just keep on keeping on. If so, what would be the technical reasons for this?
It could be amplifier-related or maybe it's that steeper crossover slopes help - although I'm pretty sure that actives are better even at shallower slopes.
Do passive crossovers change character as power increases? We are told that air-cored inductors don't saturate, and that heat isn't a problem with normal listening levels.
Are there more implications to high series impedance than simple frequency response issues and damping? Does it also contribute to harmonic distortion/IMD in a real world driver as opposed to the simple models, especially at higher volumes?
My perception is that passives begin to sound strained at high volume, while the actives just keep on keeping on. If so, what would be the technical reasons for this?
It could be amplifier-related or maybe it's that steeper crossover slopes help - although I'm pretty sure that actives are better even at shallower slopes.
Do passive crossovers change character as power increases? We are told that air-cored inductors don't saturate, and that heat isn't a problem with normal listening levels.
Are there more implications to high series impedance than simple frequency response issues and damping? Does it also contribute to harmonic distortion/IMD in a real world driver as opposed to the simple models, especially at higher volumes?
i guess high reactive currents in capacitors which arent rated sufficiently, could change in character, but id suspect an equivalent line level filter wouldnt show the same. That would lead me to believe the 'strain' would be from driving an awkward load or over stretching the amplifier, rather than a 'passives are evil' arguement.
A couple of possibilities I can think of. First since passive XOs have a non-zero insertion loss, the amps are going to be working harder to create the same SPL (all other things being equal).
Secondly the higher source impedance (which also rises with frequency due to skin/proximity effect in air-core inductors, and core losses in non-air cored ones) in the passive case will result in higher distortion of the voltage waveform at the bass driver's terminals, due to the driver's non-linear input impedance. But drivers are current driven so I don't know if this additional voltage distortion is at all significant in practice.
<edit> A third one has come to mind - for a given IMD performance, two amps reproducing restricted portions of the full audio spectrum will output lower distortion products than a single amp will. This effect does though have to be offset against the fact that IMD products outside the driver's passbands will be subject to attenuation in the passive case, not in the active one.
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well, if you have small 2way I doubt playing loud will be any issue at all 
and how about all the 2.5way speakers ?
as for the louder speakers you are talking about, yes they will probably mostly be active anyway
or what ?
but hey, that actually sounds good
I can throw together some fancy designs
just mount some drivers
and when asked about crossovers, I would just say, hey, thats your job, they are active, right ?
and how about all the 2.5way speakers ?
as for the louder speakers you are talking about, yes they will probably mostly be active anyway
or what ?
but hey, that actually sounds good
I can throw together some fancy designs
just mount some drivers
and when asked about crossovers, I would just say, hey, thats your job, they are active, right ?
skin effect at audio frequency in a coil of values typical in use and typical inductor size is a non issue, possible but probably the smallest contributor. The case for band limited amps is clear IMHO, but resistive insertion loss is less so. What distortion does such loss create if you have a capable amp in the first place? Multiple amps for multiple bands? Best idea yet. Does that place actiue filtering as the next best way to prevent distortion? Unlikely. Many more discretes and their losses to contend with, just as with the amp selection is just as valid. A good active filter SHOULD be better, but ANY active filter certainly is not.
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How high a volume are we talking about? I can ceratinly understand that in P.A. application - tho Danley's Unity Horns seem to do OK - but in small rooms?
Do you think it's related to the drivers?
Perhaps I should clarify: I'm referring to loud transients more than just sustained high volume narrow dynamic range stuff. My perception is that the actives simply deliver more 'punch' i.e. the recording demands a ten-fold increase in volume at the end of an orchestral crescendo, and the active delivers it. The passive (to my perception, at least) gives 95%. That may be an actual compression of dynamic range, or simply something like distortion conveying a sense of the system being 'strained' or running out of steam.
This is an interesting point that I have been thinking about a lot lately. I really don't know how much of an effect it has, or could have. Anyone have any expanded knowledge on this subject?
SY said he didn't hear any difference but I don't believe him
he said no difference regarding dynamic/compression....
not that it didnt sound differnt at all
btw, I wouldn't mind making my speakers active, not at all
actually, I would like to
and I would try my best to make them sound the way they do now
but if I continue my ideas about big tweeter horns and compression drivers, they will surely be active, no doubt about it
and in the end the whole speaker will probably be a mixed active/passive hybrid, and with passive tone controls
Originally Posted by CopperTop
My perception is that passives begin to sound strained at high volume, while the actives just keep on keeping on.
High frequency drivers have little voice coil mass, so this effect can happen quite rapidly.
The offset horn used for midrange in Danley's Unity or Synergy horns is an acoustical bandpass, it reduces distortion components whether used active or passive.
My perception is that passives begin to sound strained at high volume, while the actives just keep on keeping on.
Drivers impedance rises when they heat, which changes the frequency response when used with a passive crossover.
High frequency drivers have little voice coil mass, so this effect can happen quite rapidly.
The offset horn used for midrange in Danley's Unity or Synergy horns is an acoustical bandpass, it reduces distortion components whether used active or passive.
SY said he didn't hear any difference but I don't believe him
You're not that far away, come hear it for yourself.
Passive, the stock speakers could go far louder than I could stand with no sign of compression or strain. That was one big reason that they got rave reviews from a notorious rocker who used to write for Stereophile. Active didn't change that, it just made the bass smoother (through crossover and midbass chamber modifications) and more extended.
yes, its true if you play very loud
but coppertop only mentions better bass
a friend have very old Cervin Wega, and they sound very 'effortless'
but only with good and big power amps
the more the merrier it seems
funny tho, I think someone told me there is no xo on woofer
hard to believe
A lightweight, low sensitivity small dome tweeter can quickly change in impedance at less than 90 dB at one meter, a level I would not consider particularly "loud".
The change in impedance will change the frequency response when using a passive crossover, low sensitivity tweeters without a resistive pad will sound "more different" at high level than a efficient compression driver with a resistive pad that may be reducing the power by 90%.
I recently used parts from a pair of old Cerwin Vega 3 way cabinets, they had no in line components on the woofer.
There are many passive crossover speakers that use no crossovers on the woofers, if the acoustic rolloff is adequate to start with, no need to add a coil, or a coil and a capacitor.
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