Super Tweeters & Tannoy 15" Monitor Golds

[YNWaN]

One thing to consider is that most super tweeters actually roll in well before 20K and often overlap the output of the main tweeters - inevitably this will impact upon the subjective balance of the speaker as a whole.

[Marco]

Yup, and precisely why I’d need to hear some in my system first.

Basically what I need is to hear a pair of super-tweeters that I like, then buy whatever they are (as long as it involves a simple ‘plug & play’ solution, in my set-up, with no fannying about), pop ’em in - and after that, simply enjoy!

Marco.

[YNWaN]

Yeah, I concede that - what you need is a commercially made solution that you can try first. I'm really advocating a more DIY route which allows more flexibility and costs less - but isn't for everyone.
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RAAL just make drive units and although a few high end speakers do use them I'm not aware of anybody using them to make add on super tweeters (they would retail for thousands).
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DIYing super tweeters is one of the easier DIY tasks though as no cabinet is needed as such. Pretty much all tweeters/super tweeters are closed back designs and they don't require any air space behind them. In the majority of cases the crossover consists of a single capacitor wired in series to the + terminal of the tweeter. If there is adjustment it just switches between a number of different capacitor values and if there is a level adjustment it switches resistors. If you look at the model that Tannoy make (for example), most of it is really just a fancy way of holding the tweeter in position - instead of a switch you reposition pins to make the different contacts. They look really nicely made (and I'm sure they are) but you could DIY something that sounds just as good for a fraction of the cost.

Audiosmile make a nice super tweeter and I think can be borrowed for trial.

http://www.audiosmile.com/supertweeter-mkii.html

About £760 a pair though!

[Marco]

Yeah, I concede that - what you need is a commercially made solution that you can try first.

Or get someone who knows 15” MGs inside out (perhaps Paul, from RFC?) to build something for me… You know me, SPPV rules, so I’d rather have the ‘retail for thousands’ performance, minus the price tag!!

Marco.

[YNWaN]

Yes, I'm sure Paul could make a nice job of it. However, I don't know if he would be prepared to buy the bits and spend all the time making them on a trial before purchase basis (as it isn't a product he already does) though - you would have to ask him...

[Marco]

No, I wouldn’t expect him to either - nor would I do that… There are compromises that perhaps could be considered, though!

Marco.

[Reffc]

A few interesting points raised here folks and I'll throw in a few considerations for anyone considering this approach:

- getting supertweeters to integrate properly is not as easy as sitting any old ST atop a speaker and expecting miracles. As Mark has pointed out, MOST subjective opinions on supertweeters by people who've tried them invariably forget that the ST is probably (definitely) crossed over with a very large band overlap with the main speaker tweeter (usually between 10 and 16 KHz) so what they're not hearing is "effects of harmonics from frequencies above 20KHz", it's simply a raised high frequency response. it only needs raising by 1 or 2db above 10Khz to give a very definite impression of "air and space" which can become tiring with some recorded material (because it is a raised response).

- some super tweeters can mess up dispersion within the overlapping frequency band and cause comb filtering within the HF section. As traditionally they have been treated as an "add on" for many years, they are not properly integrated into baffle design so wont actually do anything good for imaging accuracy...that's just plain physics. What subjectively is thought will depend very much on the speaker they're used with and the room they're in;


- Ribbons are more popular in some camps but have a poor off axis response so need to be listened to on-axis. They have a lot of redeeming features, but personally, I favour a good quality dome (contrary to popular urban myth, a decent dome is the superior design, has wider dispersion etc etc);


- sensitivity has to be matched. Some STs are provided with level adjustment for subjective assessment and variation of output level via L-Pad or multiple L-Pad (some use carbon wipe potentiometers for this).

If your own speakers are accurate to 20kHz (ie flat) then a supertweeter shouldn't be necessary. We talk about supertweeters as if everything they do is above the audible spectrum, but most are kidding only themselves as the evidence points towards simply augmenting the treble units in the audible band by lifting tweeter response. If you can immediately hear a super tweeter then most likely it's crossed over well within the audio band.

Personally, I consier them of limited value if the tweeters in speakers are correctly implemented. What they can do is make up a little for poor dispersion design of existing tweeters or baffles by removing them from baffle constraints and allowing their directivity to lift response back to a flat response if the seating position is off axis (ie you can point the supertweeter at your ears!). Toe-ing in the speakers should have a similar result if they are at the right height and the tweeters are functioning properly.

As Mark suggests, I could make them up very easily but not for trial and on the strict understanding that it would be more an experimental route for the customer than a guaranteed route for all the issues mentioned above.

[walpurgis]

Having used numerous supertweeters in various configurations (forward firing/upwards/backwards angled up), all I can say is that nothing is predictable. I've found that the higher they are rolled in (filter curve), the better. If you can actually hear noticeable output from the supertweeter connected on its own, then something is likely not right. What you should be able to detect when listening to them in system is a change when they are disconnected. It is usually quite noticeable. Changing from 'correct' phase to reverse phase also has interesting effects. The best thing is to experiment until the supertweeter has a subtle, but beneficial contribution (if ever). Sometimes they are not worth bothering with. I haven't used them for years, but I'm toying with the idea of having another go.

[PaulStewart]

Pehaps "smooth" is the wrong word 'cos they don't detract from the suberb MG attack in any way. A lot of the percieved "realness" of music reproduction is, as research has has shown, about the intermodulation of frequencies. A lot of that is the intermodulation of frequncies both ultra bass and ultra treble with the audible range. The intermodulation product is there and greatly enhances our perception of the music. One of the resons CD never quite makes it for me is the brick wal, filters at 20Hz and 20kHz. STs and not just with Tannoys make the sound, more coherent, shall we say. Marco, if you were nearer I'd bring them over, may be in your neck of the woods later in the year, if so I'll bring them. You are always welcome here for a listen and a cuppa. Can't offer food I'm still on the 1200 calorie a day diet Mind you I'm 4 1/2 stone down now 3 more to go.

[montesquieu]

FWIW I tried several pairs of supertweeters with the Tannoy 15in MGs/GRFs - Townshends, Tannoy ST50s, Audiosmiles (factory set up), and some ebay cheapos I can't remember the name of.

All of them added something, which was typically enjoyable for a bit, but I got tired of whatever it was fairly quickly in all cases and sold them on. I kept trying different brands to see if anything would be a keeper. None were. Though I can see the attraction perhaps if someone's hearing is down a bit in the HF.

I don't reject supertweeters totally. With Quad ESLs - I suspect due to their limted HF response - Townshends in particular worked superbly. They also worked pretty well on some Fostex single driver folded horns, but again these had limited HF response about about 10khz.

My conclusion - properly sorted Tannoys don't need them as they go well beyond most people's hearing without any bolt-ons. Lesser speakers might benefit. I'm also of the view that what they are mainly doing is generating a lift in the audible frequencies - I don't buy the bat-sensor mystical properties of inaudible vibration theories.