Super Tweeters - Fact or Flights of Fancy?

[Welder]

Wouldn’t you need a power amplifier that extends beyond say 20kHz for a super tweeter make any difference in an otherwise flat response 20Hz to 20 kHz system?

Is there any information past 20kHz on CD’s?
What about records? Can you retrieve anything beyond 20kHz from a record?
I thought very high frequency signals on vinyl caused terrible problems for retrieval and reproduction.

Don’t “ordinary” tweeters cope with 20kHz?

Doesn’t adding another tweeter, super or not, just boost the audible HF range; ruining an otherwise flat response?

[jostber]

Some more explanations here on the Townshend site:

http://www.townshendaudio.com/archives/1048

and here:

http://www.positive-feedback.com/Iss...pertweeter.htm

[Welder]

Some more explanations here on the Townshend site:

http://www.townshendaudio.com/archives/1048

and here:

http://www.positive-feedback.com/Iss...pertweeter.htm

Hmmmmm, I think I'll stick to just one the one good quality tweeter per box for now.

[michaelhigh]

Radio Shack used to make a supertweeter back in the 70's. It's no longer available but shows up used pretty often on the bay, as there were thousands sold you could source them still if needed. I feel like this: unless you have one main system that's totally complete without any shortcomings they might be superfluous. If your speakers are lacking in the high range, supertweets might be the ticket to getting that upper level extension you're lacking. I had a friend that was attempting to build a pair of PA speakers on an extreme budget back in the late 70's, and with RS woofers and supertweeters, he built some enclosures and placed these on top, to great effect. They couldn't compete with his 1971 Marshall Super Lead 100, but that was a lesson learned about the nature of that particular beast. I'd, getting back to the original topic, pair these tweeters with any box lacking tweeters and expect good if not great results.

[Welder]

Well, I read the blurb in the links again and although the author has valiantly tried to cover his arse with what information may or may not be retrievable from the various mediums he has overlooked one or two very important points.

If your power amp only sends 20kHz max it really doesn’t matter what’s going on at the speaker and source, 20kHz is all the speaker will get.

As far as I can tell the “super tweeter” is just a tweeter with extended frequency response.
Granted a great many “normal” tweeters start to run into problems at the highest frequencies but suppose you have one of these for example


http://www.wilmslow-audio.co.uk/scan...0000-446-p.asp

surely power amps don’t go past 30kHz in general.

So, while there may be advantages in tweeter types; ribbon v dome for example and this may have some bearing on the quality of the high frequencies, 30kHz seems near enough bat like to cover human perception and all the stuff about how well produced high frequency sound effects ones perception of lower harmonics etc shaould apply to a single decent tweeter shouldn't it?

[jostber]

Tannoy also make some: http://www.stereofil.no/produkter/ho...noy_st200.html

If they make my system sound even better that is all that counts for me.

[Reid Malenfant]

Well, I read the blurb in the links again and although the author has valiantly tried to cover his arse with what information may or may not be retrievable from the various mediums he has overlooked one or two very important points.

If your power amp only sends 20kHz max it really doesn’t matter what’s going on at the speaker and source, 20kHz is all the speaker will get.

Most power amps will more than likely be less than 3Db down at 50KHz or so, after all we are after as flat a response as possible to at least 20KHz As a simple Bessel type filter is used on the amp input (RC network) the response is quite a bit more extended than first might appear.

A decent modern power amp should have a bandwidth that extends to 100KHz - 1Db ensuring a flat response output with hi res files such as 24/192. Most decent quality amps of even the last 20 years should be able to manage that unless excessively filtered possibly due to slew rate limiting

[Welder]

Ah, okay, so when an amp spec says 20kHz frequency response, does that mean that they will actually send higher frequencies to a speaker or am I getting bandwidth and frequency response mixed up?

Ah, I have assumed that many power amps are hard limited but this doesn't seem to be the case.

[Reid Malenfant]

The audio band is generally classed as 20Hz - 20KHz so your amp must be good enough for at least that

With Red Book CD the response will be limited to approximately 22KHz or half of 44.1KHz, there will be no musical information above that frequency. However it can extend down to virtually DC & there is often a heck of a lot of sub 20Hz material on a lot of CDs.

When it comes to SACD, DVDA, certain DVDs/DAT & Blu Rays there is an extended response. In the cast of DAT/DVD this can be to 24KHz. SACD extends it to 50KHz or higher similar to DVDA, though this can be up to 100KHz. Blu Ray can extend things to 96KHz...

You may argue that there are no instruments that produce fundamentals at these frequencies, but you must remember that it's the harmonics that make a flute sound like a flute.

While you may well not have bat ears Frequencies outside of the range that we can hear do effect frequencies we can here directly by intermodulation. These tiny bits of extra information can have a quite an apparent effect.

[goraman]

I once tried some Fostex super tweeters, they do well for older speakers that have a sharp roll off at say 14 to 16 khz. horns ect...
I used them with a pair of KLH modle sixes and they took over at 16 khz. on up.
But if you are using a pair of modern speakers (single fullrange drivers excluded) they really aren't much use unless you have extreme hearing lose in the higher range but that can be equalized or just switching to a higher sensitivity tweeter of the same outside diameter.
most amps will extend beyond 20khz. but unless you are spinning wax with a really cartridge they won't be any benefit and your ears will have to be very clean and young to hear a 30khz. sound wave any way.

I have a ton of trees just outside my front door and when I was running a pair of sound labs late in the evening bats began flying around the screen door while playing Vivaldi's Four seasons (Spring ).