General consensus of >20khz sound?

[crackyflipside]

Using REW I figured that my hearing for pure sines is good up to 21khz @ 70db (ambient noise in the computer room is 67db)

Now with a product like this: http://www.av123.com/products_produc...s&product=77.1

Or even just having a supertweeter in the loudspeaker which on paper and measurements is flat to 45khz, would there be a noticeable effect significant enough to hear a difference?

Are supertweeters popular with the DIY hi-fi speakermakers? why?


Edit: I know most people still consider the subsonic frequencies <20hz to be insignificant in sound reproduction but the truth is that while you may not be able to hear pure sines at low volumes of subsonic material, when integrated into a complete audio system the subsonic frequencies do affect and modulate the rest of the sound making even low level subsonic material fairly easily noticed. Could this be the same case with the supertweeters?

[augerpro]

I read the study that started alot of this trend for extended tweeter response. All in all it's pretty persuasive. But it really only matters IF you play SACD or DVD-A AND the sound engineer leaves that HF info in the tracks. There are alot if IFs involved so I'm not real keen on using them.

[Mazeroth]

If you want my opinion I wouldn't worry at all about anything over 20khz. In fact, once you hit somewhere in the neighborhood of 15khz it's pretty hard to distinguish even a 6db peak or dip in the response.

Also, how did you measure your frequency capabilities? I've never heard of someone that could hear all the way out to 21khz, let alone a guy that could (women are known to have better ears). What you may have been hearing was distortion.

[Kal Rubinson]

I read the study that started alot of this trend for extended tweeter response. All in all it's pretty persuasive.

Which study was this? One of the Oohashi papers? I didn't find them persuasive. Are there others?

Kal

[joecarrow]

Mazeroth, I've heard of people who can legitimately hear has high as 27 khz. Still, I agree with you that there was probably a problem with Chris B's test method. I don't think that many of us have access to the low distortion calibrated sound generators that an audiologist would use. I tried some sine wave sweeps with an old sound system I had, and I could clearly hear the harmonics sweeping up in frequency as the fundamental changed. That wasn't all- there were other parts of the sound that weren't a pure sine wave. Even if your system is quite good for music, it's still a really rough test to put in pure sine waves and expect to hear nothing but pure sine waves on the output.

To answer the original question- I don't think that very much recorded material exists that contains anything at all above about 22khz, so even if it's important the industry has sort of overlooked it.

One school of thought is that if your tweeter is capable of going to 30 or 40 khz, it's better behaved between its low end and the top of your hearing. I tend to buy into that, but only so much. People seem quite happy with the Dayton Reference RS28a, and it barely makes it to 20 khz. I'm happy with my Seas H1212, and it has a huge nasty peak at 26 khz.

As for the effect of supersonic sound on what we hear- my mind is open, and I haven't really heard much either way yet.

[Tommythecat]

From my experience, anything over 15k doesn't hold much weight. I can still hear tones to 17k or so, and in music im sure it makes an impact. But a flat response above 15k for me is much farther down the list of concerns, especially compared to midband (200-4k region). Beyond large deviations (ie 6+db variations in peak-dips) the tweeter just needs to present something, even if there is a 6db/oct. drop from 10k up.

edit: I also think there may be some consideration of what kind of dispersion you're looking at achieving vs. the upper-end freq. response.

As far as bass goes, 30Hz is a fine 3db down point for most music because there isn't much material down there. Whatever exists, beyond organ pipes or whale humpings, is most likely noise. (Of course HT needs are much different)