Beryllium Tweeter

[kevinlomax]

what do you think?

Alberto

[wigginjs]

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[kevinlomax]

sorry!
this:http://www.focal-jmlab.fr/car/downlo...chesHP/Tbe.pdf

Alberto

[Puggie]

Well I havn't heard the Focal, but the original beryllium boys Yamaha made the NS1000 with Beryllium mid and tweets many years ago and they are very nice indeed (If a little imposing in the livingroom).

[Hennie]

I had Yamaha NS-1000's and they were very revealing in the upper ranges. The rest of the equipment had to be of a very high standard in order to avoid fatigue. I could not quite get that right, though others had better luck...

[ScottG]

1. The price will be exhorbitant.

2. The neo magnet they are using is probably less than an n45 (i.e. there are better magnets being produced by others).

3. Because the mass of BE is so low the VC wire must weigh quite a bit for such a low eff. and/or the diaphram is overly "thick".

4. The high fs will limit its use for mid driver pairing.

5. The high freq. off-axis response (if I'm reading it correctly) is rather good at only 5db 30 degrees at 20kHz, (less good if that's 5db at 15kHz).

#'s 4 and 5 essentially mandate that this driver be used ONLY as a tweeter and combined with a mid that has good off-axis response well above 4kHz.

[5th element]

The tweeter is 10 dB down at 20khz. If I am looking at this in the right way I think this tweeter is for car use not home.

[DSP_Geek]

Originally posted by 5th element
The tweeter is 10 dB down at 20khz. If I am looking at this in the right way I think this tweeter is for car use not home.

No, the graph x-axis labels are messed up. Count over from the 1294 Fs, and it becomes apparent the 10000 label is shifted to the right by one division. The vertical it labels is actually 20000, and the 10 dB down at 20 kHz is actually 30 degrees off axis.

In any event, Focal curves are a bit more optimistic than Seas (not saying this is a bad driver, far from it); I'd like to see some measurements done by a third party.


Cheers,
Francois.

[wintermute]

Originally posted by 5th element
The tweeter is 10 dB down at 20khz. If I am looking at this in the right way I think this tweeter is for car use not home.

On axis response is down at most 2db at 20K, yeah the 30 degree off axis starts to drop off at about 10Khz and is down 10db at 20Khz..... I think you will find that this is simply due to the size and shape of the dome. (and is really quite good)

Comparing to a morel supreme 110 It admittedly seems to start to drop off sooner (30 deg off axis), but the response at 20Khz 30 degrees off access is quite a bit better than the morel, which is up there with the best tweeters......

I think you will find any tweeters(unless very small) will be drooping quite a bit at 20Khz 30 deg off axis, it is simply the same physics that says for instance a 5" driver will start beaming at 3Khz, it is just that the freq is now higher because the radiating area is smaller (I just did a quick search on scanspeak and found that their ring radiator, and revelators show the same behaviour).

Tony.

[EFHeath]

If you are particularly interested in experimenting with beryllium drivers, don't forget TAD. They make both tweeters and a midrange or two, if I recall. A google search should be able to find a DIY source.