Was wondering if there was any information on what the frequency response is for the 7700 above 20kHz? Say, up to 45kHz or 50kHz? TIA.

You seem particularly interested in frequency response in the ultrasonic range this evening. That's not a range that is typically covered in specs. You might want to give Outlaw a call to find out of they've done much testing in that range. Are you planning to drive a super tweeter of some sort?

Yeah, posted in multiple categories since each of the amps is different. And yeah, hoping that sometime soon I can get some speakers that go that high. Thanks.

To what end? Trying to annoy the neighbor's dog????

Well, SACD have response up to 100khz. The only argument I can see for that being of any use is if the 100khz sound wave interferes in some perceivable way with audible sound waves...

That would be pretty easy to test. Just make a short file with no information above 20khz, and then make one with tons, see if you can tell any difference. My headphones go up to 120khz or something silly like that....

I have actually tested my hearing (which by most accounts is supposed to be "good") and I can't hear squat above about 16khz. I mean zero, even at high power levels. And I'm still in my 30's. 8-)

Those high harmonics might look intriguing on paper, but I suspect they have little effect (if any) on real world performance when you consider the limitations of the human ear.

Cheers,

Ritz: I totally agree with you.

Being able to "hear" something at a frequency is not the same as being able to "feel" something. The required SPL curve is low in our regular hearing range, and goes higher when you go outside that range. However, even if you can't hear something, say 100dB of 5Hz, you can still feel it. Of course, hearing tests would not be subjecting you to 100dB of anything.

Feeling low frequency is a reasonable assertion - hard to deny the sensation of shaking floor joists that a sub can generate even after it dips below 20Hz. Feeling high frequencies is a bit hazier an issue, at least for me.

Not only hazy. It's pure fantasy. Humans just don't have the sensory capacity to detect a 20khz pulse if they've gotten much past the adolescent years when many of us are still lucky enough to be able to hear tones that high. Next, Joshua will be telling us he sees dead people. 8-)

Cheers,

I tested my hearing with a tone generator and can only hear about 14.5kHz. I am in my mid 30's. Cool, now I don't have to worry about equalizing anything above that frequency range. Now, if my vision would just get worse, the ScreenPlay 4805 would look even better.

Perhaps I should provide some research to back up my claims. However, it would appear that above 20kHz, or 22kHz, or 18kHz, or whatever high point you accept as the top of normal human hearing, those extra high frequencies aren't detectable unless by direct contact with the source.

Whether or not you would consider air to be a suitable direct contact source, you might accept the idea of non-detectable fluid pressure having a physiological or psychological effect on the human body. The same way infrasonics can be used as a weapon against humans, and is the reason for "spookiness" in old houses.

High frequencies are also very important for localization, hence the bat's hearing and "speech" range. One might argue that _if_ humans can perceive higher frequencies, whether or not they consciously realize it or not, then localization would improve. Thus improving imaging in audio reproduction.

Ultra Hearing Fetus
Ultrasonic Hearing in Humans: Applications for Tinnitus Treatment

I've actually seen that paper on tinitus before (wear hearing protection at the rifle range folks!). It's really only relevant for bone conduction. So a transducer would have to be physically touching you and the paper still says that it's not nearly as perceptable nor as accurate as the frequency discrimination in the audible range.

Cheers,

Yeah, so I'm still skeptical, but figure it can't hurt since the speakers I would like to get go high but I'm not interested in them for the super high response.

The 7100 is already 20Hz-20kHz at +/-0.1dB, so I figure it might go way up at +/-3dB. But I have no idea since I don't have measurement equipment myself.

I have a HF loss that starts at 2.5 KHz, as well as tinnitus (the Army didn't issue me ear protectors in basic training 53 years ago), but I could easily hear the difference in HF clarity when I changed from my Adcom TPA500 to the 990. I'm skeptical of any sweeping claim that the absence of signal above 20 KHZ is undetectable by humans, especially if they have a chance to compare it with similar material that has ultrasonic signal content. I think there would be a difference in subharmonics or beat tones down in the directly audible range. I'd like a chance to blind-compare the sound of my Maggie 1.6QR's (- 3db at 24 KHz) with the 3.6R's, which go up amost another octave: I would be surprised not to hear a difference.

Harman Kardon used to publish specs in the 1980s that went to 100 kHz, not because anyone could hear that high, but 'theory being that an amp needed to be able to handle frequencys far above the hearing range to ensure that some HF performance defect didn't cramp any frequencies just within the range of hearing. 'Not sure about their exact theory or if I buy it...just throwing it out there.