I know that virtually every reputable and legitimate eletronics/speaker engineer considers changing cables/interconnects/power cords in an attemp to alter sound to be a pursuit among the mentally handicapped. Maybe I should use a CD de-magnetizer to reduce 'sibiliance' .
I've done many A/B comparisons among different types of amps, inlcuding Krell, B&K, Adcom, Rotel, Classe', a host of integrated recievers such as Pioneer, Denon, etc. along with a few tubes. I simply have a lot friends who sell Hi-Fi and like to 'borrow' equipment on weekends.
No arguement from me that a big change in amplifier architecture will alter the general sonic signature of a well designed and efficient speaker. However, those differences tend to be general in nature and will change the general character of treble, or weight of the bass. My 200wpc B&K amp for instance produces an obviously different sonic signature than a 200wpc Adcom considering both amps lie on near opposite ends of the spectrum. My B&K produces a more laid back treble and rather fat mid-bass, while the Adcom or a typical high end consumer reciever is just the opposite. The differences though are general and cover a very large octave range, not a particular vocalization.
Yes, tubes can get more radical, but a 'firebottle' based amp won't make a cheap, beaming, metal dome sound like a 1" silk - sorry. The issue I'm referring to is transducer and/or crossover based, not a power supply/source issue. My thanks to those offering pragmatic replies and not 'drinking the kool-aid'.
Wseaton said:
Well, I was probably too restrictive on my frequency range estimate, as anything from perhaps 3-7k can probably cause some of what you are describing - although a 6k ribbon resonance (much larger ribbon with a cavity resonance) has caused sibilance and enhanced guitar articulation noises and really harsh female vocals on a friend's pair of speakers.
The broadening directivity issue will not show up on a single gated on-axis response plot, but it would probably show up on an RTA measurement with pink noise if you have good enough resolution on the RTA - 1/3 octave or better. It would also be visible on a polar response plot.
Legacy speakers look neat, but it is really hard to integrate lots of drivers. From the response plots in reviews I have seen, they don't always measure that well, but get fairly decent reviews as "big sounding" speakers. Difficulty in speaker design goes as something like the number of drivers times the number of crossover components raised to some power. This is to say it is probably 100 or more times as difficult to design a 4 or 5 way as it is to design a 2 way. On a similar vein, I have never seen measurements of a VMPS speaker
Wseaton said:
Okay, i can't call my speakers that, i use textile-dome-tweeter
+ 2 "paper" woofers (17cm) with a rather cheap crossover.
Of course no amp can make a bad speaker sound good, but a not
so good amp will make sound any speaker bad.
I even have (had) one commercial amp at hand giving distorted trebles...
Mike
I think skilled electronics engineers like me know that EVERYTHING in the signal path has an influence. It is only a question of HOW MUCH.
I admit that a cable won't have so much influence that it causes such an extreme anomaly as you described.
Chances are great that it is indeed the speakers themselves.
But you can't still rule out the amp !
Ever heard an amp on the verge of oscillation ?
Or an amp with the bias set inadequately ?
Or ..... ?
Regards
Charles
Hi Wseaton,
I'm not sure where the effect is coming from (don't want to get into that debate), but I've found that:
Boosting the 5-10k octave increases clarity of the vocals and too much can be fatiguing (esp. if the octave below is also emphasised).
Boosting the 8-16K octave causes the 'cha' and 'sss' emphasis that you mentioned.
The cause could be from a number of places. It could be deliberate EQ to emphasise this in the HT set-up (some of these 'receivers' can do this in the digital domain). It could be a design flaw or possibly a design intention in the cross-over (if the speakers are aimed at richer, older people then this could a be deliberate attempt to counter hearing loss). It 'could be' high impedance cabling (ie. twisted CAT5 can act as a "very faint" high-pass filter and can also drive some solid-state amps into oscillation). But I'd guess the first 2 are far more likely, and I'd bet on the first one...
I'm not sure where the effect is coming from (don't want to get into that debate), but I've found that:
Boosting the 5-10k octave increases clarity of the vocals and too much can be fatiguing (esp. if the octave below is also emphasised).
Boosting the 8-16K octave causes the 'cha' and 'sss' emphasis that you mentioned.
The cause could be from a number of places. It could be deliberate EQ to emphasise this in the HT set-up (some of these 'receivers' can do this in the digital domain). It could be a design flaw or possibly a design intention in the cross-over (if the speakers are aimed at richer, older people then this could a be deliberate attempt to counter hearing loss). It 'could be' high impedance cabling (ie. twisted CAT5 can act as a "very faint" high-pass filter and can also drive some solid-state amps into oscillation). But I'd guess the first 2 are far more likely, and I'd bet on the first one...
Stereophile's measurements on this speaker can be found here: http://www.stereophile.com/loudspeakerreviews/104legacy/index5.html . There are some peaks in the response that could explain what was heard.
Would you guys say that, in general, aluminum domes have more a problem with sibilance, or that silk domes have less of a problem? I've been wondering how the particular monitors a recording engineer uses affects how aggressive they are at dealing with sibilance when mixing a recording. I'm thinking the type of tweeter their monitors use would have a big influence on that.
Would you guys say that, in general, aluminum domes have more a problem with sibilance, or that silk domes have less of a problem? I've been wondering how the particular monitors a recording engineer uses affects how aggressive they are at dealing with sibilance when mixing a recording. I'm thinking the type of tweeter their monitors use would have a big influence on that.
resonances
Despite what many people assume there is no reason why a metal dome should sound "metalic". A 25mm. Al dome has its first break up mode above audibility, for Beryllium its way above. Cloth domes are in some form of break up from quite low frequencies, and as mentioned before mylar type domes were noted for a 10kHz. resonance that was largely due to the voice coil inductance resonating with the moving mass, the peak in the Philips tweeter could be tamed by means of a 10Ohm. series resistor.
I do know that this type of resonance was built into some types of cone tweeters, in 78 records there was no appreciable content above 8-10kHz. and this peak was put there to give the illusion of high treble content, they also helped the ceramic type pick up cartridge in this respect, some microphones also have sibilance and this can be clearly heard on some recordings from the early vinyl days.
Despite what many people assume there is no reason why a metal dome should sound "metalic". A 25mm. Al dome has its first break up mode above audibility, for Beryllium its way above. Cloth domes are in some form of break up from quite low frequencies, and as mentioned before mylar type domes were noted for a 10kHz. resonance that was largely due to the voice coil inductance resonating with the moving mass, the peak in the Philips tweeter could be tamed by means of a 10Ohm. series resistor.
I do know that this type of resonance was built into some types of cone tweeters, in 78 records there was no appreciable content above 8-10kHz. and this peak was put there to give the illusion of high treble content, they also helped the ceramic type pick up cartridge in this respect, some microphones also have sibilance and this can be clearly heard on some recordings from the early vinyl days.
Hmmm. From the Stereophile article:
...I, on the other hand, suspect that possibly 'PB' may be a little lacking in his top-octave hearing, or maybe the amplifiers used (none of which I have familiarity with) in the review emphasise midrange at the expense of anything over 10K Hz. IMO, of course.
...I, on the other hand, suspect that possibly 'PB' may be a little lacking in his top-octave hearing, or maybe the amplifiers used (none of which I have familiarity with) in the review emphasise midrange at the expense of anything over 10K Hz. IMO, of course.
sibillance
Hi Wseaton and all,
I encountered a similar problem once and cured it. As a matter of fact there was very little of sibillance and only with some material but still anoying. At that time I had a nice new mosfet PA, linear preamp and a 3 way Dynaudio kit system. I also had other amps and 1/3 octave equalizers. The latter helped me to quickly identify the problem.
Anyway, first you have to find out the source of your problem. Sometimes it is a combination of the amp, crossovers and a speaker (tweeter) and if so may require more playing around.
You may start with the amp as it is the easiest to test. Borrow an amp from a friend, plug it in and check if sibillance disappeared. If not then play the tweeter directly from the amp bypassing the crossover. Choose a CD with low bass content and play it at low levels. If you have tone controls turn the bass control down. You may test mid driver(s) as well. These two tests will tell you enough.
In my case I had to redesign the crossover (first order) and had to shift the crossover frequency to 7-8kHz (I do not remember exactly, it was in the 1980s) . The mid driver (D54) was working up to its upper limits but sibillance was gone no matter what material was used.
Cheers,
Hi Wseaton and all,
I encountered a similar problem once and cured it. As a matter of fact there was very little of sibillance and only with some material but still anoying. At that time I had a nice new mosfet PA, linear preamp and a 3 way Dynaudio kit system. I also had other amps and 1/3 octave equalizers. The latter helped me to quickly identify the problem.
Anyway, first you have to find out the source of your problem. Sometimes it is a combination of the amp, crossovers and a speaker (tweeter) and if so may require more playing around.
You may start with the amp as it is the easiest to test. Borrow an amp from a friend, plug it in and check if sibillance disappeared. If not then play the tweeter directly from the amp bypassing the crossover. Choose a CD with low bass content and play it at low levels. If you have tone controls turn the bass control down. You may test mid driver(s) as well. These two tests will tell you enough.
In my case I had to redesign the crossover (first order) and had to shift the crossover frequency to 7-8kHz (I do not remember exactly, it was in the 1980s) . The mid driver (D54) was working up to its upper limits but sibillance was gone no matter what material was used.
Cheers,
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