Regarding supertweeters


hello!
in my ears theres no doubt the supertweeters are worth the money(from what ive heard in some systems). but,- theyre supposed to take over for the standard tweeter where it cant go higher. what if the cd player and amplifier cant produce the over 20000hrtz "normal" range? ive only seen some cd players do this, where it says from 15-100000hrtz or so. my cd player and amp says 20-20000. does that mean a supertweeter will not do any good in my system?
hifimannen

Showing 2 responses by gregm

Hifimannen, in order for the supertweet to contribute (musical) supersonic sound this content (sound) must be on the storage medium in the first place. It rarely is, as Eldartford notes.

Further, no cdp plays over 20k. What is there is often spurious hi frequency noise (unless you throw a sine at it).

Even further, if yr amp specifies 20kHz then its amplitude response will be much reduced beyond that --limiting the usefulness of a supertweet.

To make things worse, our ears' sensitivity typically goes down as the frequencies go up over 3kHz (i.e. to our ears, a louder signal at say 10kHz will sound as loud as a soft signal at 3kHz).

Ultimately, a supertweet usually functions as a "supratweet", intensifying (i.e.playing in conjunction with the nromal tweet) ordinary audio frequency signals over 13kHz or so -- thereby creating the effect of "spaceousness".
will it not be very difficult to calibrate the two tweeters to eachother so the frequenses dont "crash"?
As you correctly note it is VERY difficult to correctly align the two drivers. Eldartford hints as to why this is so (a fraction of an inch & you're off many degrees in phase... etc). Unlike he, I would like to have the top part of my spkr playing as "correctly" a possible, so would welcome a 1st order crossing for the supertweet (which makes the story even more complicated).

Zaikes: while you can't "hear" you may "perceive". However your point is very valid IMO. OTOH, it's not necessary to have supertweets beaming -- their 15+% dispersion is often OK. Again, however, your point about in room absorption is valid for most rooms.
Also, as you note & I have experienced (mentioned in my 1st post), there is reinforcement in the upper AF octave and that's what attracts users...

Ultimately, as you note, it's good to have extended HF response for exactly the reasons you mentioned -- rather than hoping for actual musical content in the 50kHz region!