Pano,
I can't discuss Earl's speakers as I have not heard them but I have seen a phenomenon that could have an explanation for high level distortion in compression drivers. I only have close experience with some of the older Radian compression drivers. These were 1" drivers that I have used in the past in my speakers. A friend of mine was one of the engineers there at one time and he informed me that there was a resonant problem in the upper frequency range about 16Khz in level. You could use a notch filter with a high "Q" to cut a notch at this frequency and it would fairly well remove the problems at normal listening levels. But push that driver hard and even with the notch filter that resonance would rear its ugly head, it would become apparent though the level was lower than the average sound level, it would come up in level high enough that you would become aware of that upper frequency hash. This was a mechanical resonance that he assured me was in the driver, there was fix in a modification to the phasing plug but it was not something that Radian ever took care of in those models of drivers. I can imagine that many compression drivers also have resonance problems that are not always easily detected until a high enough spl level is reached. I have never seen much information on compression drivers that is not based on low input power, distortion levels at the upper limits of output are seldom seen, at least I haven't seen much of that in print.
I can't discuss Earl's speakers as I have not heard them but I have seen a phenomenon that could have an explanation for high level distortion in compression drivers. I only have close experience with some of the older Radian compression drivers. These were 1" drivers that I have used in the past in my speakers. A friend of mine was one of the engineers there at one time and he informed me that there was a resonant problem in the upper frequency range about 16Khz in level. You could use a notch filter with a high "Q" to cut a notch at this frequency and it would fairly well remove the problems at normal listening levels. But push that driver hard and even with the notch filter that resonance would rear its ugly head, it would become apparent though the level was lower than the average sound level, it would come up in level high enough that you would become aware of that upper frequency hash. This was a mechanical resonance that he assured me was in the driver, there was fix in a modification to the phasing plug but it was not something that Radian ever took care of in those models of drivers. I can imagine that many compression drivers also have resonance problems that are not always easily detected until a high enough spl level is reached. I have never seen much information on compression drivers that is not based on low input power, distortion levels at the upper limits of output are seldom seen, at least I haven't seen much of that in print.
Execpt of course that I have heard the Gedlee speakers get rough at high levels. Sounded just like distorting compression drivers to me.
The waveguides are very nice, but drive that little 1" Cd hard enough and you'll hear it.
A test like Art's would be great. An actual test of the audibility that any one can access. That would go a long way to convincing me and probaly others. Remember the old saw about extrodinary claims and proofs? I'd be very happy if its true - but remaine skeptical.
Pano,
If you are still around NC, I would be happy to entertain a listen in my room with Earl's designs, no problem. The only other speaker that I have listened to that does satisfy me and doesn't sound, 'Distorted' at VERY high spl. (+100dB at the listening position) levels was Danleys at a colleagues home near Asheville,NC.
Best regards,
Anand.
Well amplifiers get rought when you turn the volume up, horns reveal these more easily. You just need better amplifiers.Execpt of course that I have heard the Gedlee speakers get rough at high levels. Sounded just like distorting compression drivers to me.
The waveguides are very nice, but drive that little 1" Cd hard enough and you'll hear it.
A test like Art's would be great. An actual test of the audibility that any one can access. That would go a long way to convincing me and probaly others. Remember the old saw about extrodinary claims and proofs? I'd be very happy if its true - but remaine skeptical.
Two drivers measured to have the same SPL can sound different in perceived loudness. Basically it is impossible to conduct a fair listening comparison scientifically unless you can be sure that all equipment are designed to be matching a certain certain criteria. This is impossible to do with existing equipment.
Soongsc,
It is hard to imagine that any decent amplifier can't drive a single pair of compression drivers. Perhaps a single channel also driving both the compression driver and a bass speaker could have problems but if you are only driving the top end with a separate channel not likely to happen unless you are using an under powered amplifier. Even a small tube amp should handle a compression driver.
It is hard to imagine that any decent amplifier can't drive a single pair of compression drivers. Perhaps a single channel also driving both the compression driver and a bass speaker could have problems but if you are only driving the top end with a separate channel not likely to happen unless you are using an under powered amplifier. Even a small tube amp should handle a compression driver.
Yes it could have been the amps or even the woofer. But it sounded like a stressed compression driver. I dont know that it was, but that 's how it sounded. Which is one reason I would enjoy audible proof that it was not the 1" driver. I'm all ears, so to speak. A good listening test would convince me.
Execpt of course that I have heard the Gedlee speakers get rough at high levels. Sounded just like distorting compression drivers to me.
The waveguides are very nice, but drive that little 1" Cd hard enough and you'll hear it.
A test like Art's would be great. An actual test of the audibility that any one can access. That would go a long way to convincing me and probaly others. Remember the old saw about extrodinary claims and proofs? I'd be very happy if its true - but remaine skeptical.
When the Summas were in my living room, the following scenario would happen at least once a week:
I'd be sitting there, watching a movie or listening to some music, with everyone in the house. No one is complaining that the music is too loud, or to turn down the movie. But when we'd try to have a conversation, after a minute or two, we realize that we're shouting at each other. Literally yelling.
And that's the really bizarre thing about the Summas, that ability to have them playing at such deafening levels and not be aware of it.
I haven't had this happen even once with the Vandersteens.
I would have been a lot more amazed if they weren't capable of that!!
Using pro drivers, capable of ear shattering volume levels with appropriate amplification, makes the job so much easier for any domestic situation ...
not so surpising
Have had this happen for a few decades of high volume listening (>100dB @ 12 - 16 feet)... not too unusual, with decent speakers.
What's really fascinating is listening to high dynamic range classical, with orchestral peaks and quiet oboe solos and such, strike up a brief conversation during(about) the quiet passages, and then a sudden burst of orchestral crescendo that sounds like it will never end!!
Talk about jump factor!
Have had this happen for a few decades of high volume listening (>100dB @ 12 - 16 feet)... not too unusual, with decent speakers.
What's really fascinating is listening to high dynamic range classical, with orchestral peaks and quiet oboe solos and such, strike up a brief conversation during(about) the quiet passages, and then a sudden burst of orchestral crescendo that sounds like it will never end!!
Talk about jump factor!
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I think it is a misconception of amplifier driving capabilities. Tube power amplifiers generally have output transformers. This decouples speaker from the amplifier quite significantly.
My personal experience is that simple grounding and layout of the circuit can significantly influence the sound, and in some cases even the chassis grounding point can change sound. Power supply matching to the circuit is also another area generally not expored. As you can see most research consider the power supply separately with little consideration of interaction between the circuit. Damping of amplifiers also need more data revealed to consider the full spectrum instead of just a single number. There are more, but it makes no sense to talk about it if people are just going to reject the idea using generalization. Each case is unique, and needs to me considered individually.
One chip amp I was working on sounded like that until layout and grounding scheme changed. But I cannot say that is the only cause. Closed volume in a VC former creates a sense of compression in a different way. Some times it is faster to list all the possibilities and make some changes to see what happens. For example, in one case I did a simple mode analysis using Sound Easy, then just poked holes on the VC former adding more until I heard improvement, and still more until I could not hear improvement. More precise analysis could be conducted to optimize between VC stiffness and vent.
Just on the amplifier thing, if you can deliver several hundred watts in class A this is not an issue. Very few reviewers do this. And if you cannot do it then the amp issue probably masks the less obvious differences we are looking at. The test amplifier and associated components have to be exemplary both technically and audibly ( using the very best earphones as a start) using simple live music recorded using the best recorder replayed back for audition.
Not all class A amplifiers are the same. I have ran a modified MyRef C against a class A, it actually presented a much more convincing presentation using the same speakers. While it is a goal to design amplifiers as least sensitive to loading variation as possible, there is still a limit. I have found that high priced components do not necessarily provide the best performance, rather it is the most suitable application based on understanding of the components. Of course, purest form of recording is generally the best.
I have a hard time understanding what equipment is the best because it is possible that not well matched set of complements will result in optimum performance. This I have seen during development of interconnects. The goal of the Matchmaker interconnects was to provide optimum interface under the assumption that the input impedance of devices were flat over the audio spectrum; it turned out that not all devices were designed to that criteria, and there is no indication what they are on the devices, so obviously there was no assurance that the match is optimum unless we know such input impedance curves.
Watts is also misleading, drivers generally will exceed their excursion limits much earlier before the wattage limit is reached in normal home listening systems. In some cases, it is necessary to limit lower frequency usage of the drivers just to avoid driving them too far. I spend lots of time on this driving different music loud and see what the chances are of getting too much distortion, this low frequency cut off point is generally done by ear to get the best trade off possible. So we need to take care not to use an amplifier with too much more power than is necessary. Lots of audiophiles feel that the higher wattage capable, the less detail it reveals. I have never tried to study why this is because I do not intend to spend my life on doing such statistics.
I have a hard time understanding what equipment is the best because it is possible that not well matched set of complements will result in optimum performance. This I have seen during development of interconnects. The goal of the Matchmaker interconnects was to provide optimum interface under the assumption that the input impedance of devices were flat over the audio spectrum; it turned out that not all devices were designed to that criteria, and there is no indication what they are on the devices, so obviously there was no assurance that the match is optimum unless we know such input impedance curves.
Watts is also misleading, drivers generally will exceed their excursion limits much earlier before the wattage limit is reached in normal home listening systems. In some cases, it is necessary to limit lower frequency usage of the drivers just to avoid driving them too far. I spend lots of time on this driving different music loud and see what the chances are of getting too much distortion, this low frequency cut off point is generally done by ear to get the best trade off possible. So we need to take care not to use an amplifier with too much more power than is necessary. Lots of audiophiles feel that the higher wattage capable, the less detail it reveals. I have never tried to study why this is because I do not intend to spend my life on doing such statistics.
Class A amps will vary for reasons we all know, and sufficient watts for a test is all that matters. I.e sufficient volts say 30 volts and say 200 watts RMS or 300 watts music power.
The key thing is no cross over distortion, but using very high quality Zobel or other suitable frequency roll off.
Testing at low levels up to say 120dB or ideally higher. pulse step and waterfall.
You know that triodes are used to deliver 1000kW TRP by some FM transmitters. Big need not be bad. Some darned good live FM broadcasts
out there.
Shame for SETs but the Mumetal transformers have become so good that one limitation against push pull is minimised but at what a cost
Careful with the watts, the kind of load also counts, and voltage, impedance numbers need to match up as well as other factors I already mentioned.
Did it leave marks or knock you to the floor?