Yamaha berylium tweeters

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Sjef -

I wish I had some experience with ribbon tweeters, then I could offer better advice. But since using an array of ribbons has been suggested to deal with their limited vertical dispersion, I wonder what advantages might be gained by an array of domes. I have seen this in several line array desings. Perhaps this gives the added body/depth/staging/imaging etc. that you feel domes lack.

Just a thought. But now I'm intrigued about ribbons and the other favorites you mentioned!
 
Be aware that they can not be crossed as low as many modern dome tweeters can, so they are not interchangable in most cases. That's why I'm using a full-range (wide band) driver as midrange and that's why I tried to combine the PHL 1220 with a dome tweeter that can cross lower, wich unfortunatly the Yamaha's don't seem to like.
 
Sjef said:

I have heard the yamaha NS1000's a couple of times years ago and they sounded pretty good back then, much better in my memory as I'm getting out of the tweeters at this moment, but the best speaker in the world, naaaaah, don't think so.

Obviously you didn't hear them with £20,000 worth of Audio Research amplifiers providing the juice... :D I've never heard anything as good as this, period.. The Wilson WATT / Puppy System 7, to take but one example by comparision -well, it isn't a comparison. Utter humiliation would be more accurate (not that I've ever been impressed by Wilson Audio Kit -the most over-rated speakers on Earth). These big Yamahas are like monster Linn Kans (probably the fastest speaker ever made) with a host of improvements, and some serious low-range grunt. Well, to 30 Hz at any rate -not bad for a sealed box design.
Best
Scott
 
I've already suggested these low-price/high performance SEAS tweets, but he says he doesn't like domes, at least for his primary/reference system.

I'm afraid Sjef is on a quest for the "perfect tweeter" and he's not going to find it. We're ALL on a quest for perfection, but we have to settle for ideal, or our favorites, and that just takes a lot of auditioning and testing. The search for perfection always ends at frustration.

There might also be some dispute about the tweeter being the most important driver in a speaker, since the lion's share of the sound we hear in music is in the midrange - this also boils down to preference; for some perhaps they have simply decided that for them the tweeter is most crucial, but for many others this is most surely not the case.
 
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The Bessel

How would you wire five of those tweeters ? all in parallel seems not such a good idea and series/parallel is a bit difficult with five drivers.

Here is the schematic I made for you. There is a specific power relation and inverse driver positioning I solved for you in this case.
Yes use them open backed. Get em tight together and make a parallel frame to inset them in the baffle so to avoid secondary sources since the dispersion is going to be very wide. The Bessel lobe will 'gel' at about 2.2m from the array.

I dont know how you will like it but you will have very low Fs, big power handling, much active area and many many dBs before distortion for such a budget experiment. Post your findings when you do it.
 
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Sjef said:
Problem is that the best highs came from the most difficult units to combine with amplifiers and midranges, too bad for me.

Yes, I know what you mean.
Getting mid drivers that work with ribbon tweeters is not easy.
The same goes for researching for drivers that can work without or with minimal (1st order) crossovers.
I mean those who have the right response you need, and NO breakup.

Look at this beauty:
http://www.monacor.de/int/en/produktseite_monacor.php?artid=2120&spr=EN&typ=u
 
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An oldie

I found a magazine of Feb 1980 in my inventory. It had technical test of the Yamaha 1000M. They concluded that with little more performance could have well been the best electrodynamic in the world at the time.
So I post the crossover incase you ever cross it to a widerange at 6kHz.
Also the graph (swept anechoic sine test) where you can see the crosspoint by the a little V on it at 6k.
 

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I have been playing with a project for a few years using the NS1000 tweeter with the beryllium mids and Scanspeak 2x8535 woofers in a slim cabinet. I would agree with others that you are crossing over too low at 2.5-3khz which I tried and the sound was like you describe. The Yamaha NS1000 crossover points are very simple 500 & 6000hz 2nd order with volume pots (I have the schematic & values). I recently obtained a newish 10 year old rosewood pair of NS1000 which is slightly bigger than the black studio NS1000M. It seems to have more bass than the NS1000M and overall much smoother sounding with excellent integrated bass, midrange & tweeter sound. My DIY version is not as smooth and integrated but I used better quality crossover parts and the sound is more detailed and with deeper bass.

Overall the speaker is still one of the most detailed I have heard that keeps up with Accuton C279 midrange sound etc, infact much more detailed midrange that hits with incredible lively impact on upper drum and wind instrument notes. I would rate the NS1000 tweeter, within its design range, as better than a Seas Millenium, SS9900, 9800 & 9500, but not against Raven R1 or R2 (more extended), but it is obviously easier/better integrated with the beryllium mids.

I laughed when JMLAb brought out their Be series big fancy speakers almost claiming they were the only ones to use beryllium, and yes only in their tweeters, while Yamaha have for the last 30 years used them for midrange also.

Also you must use correct amplification such as valves to bring out the best from NS1000s. Most solid state amps will not due and sound edgy & grainy.

My main critism of the NS1000 is that imaging is flat & average compared to other cone midrange speakers.
 
Salas: Thanks for your time and effort on the bessel array, defenitly gonna try that some day.

The frequency response of the NS1000 that you posted show the same HF roll-off as I measured on my tweeters, so they might be o.k. after all.

Yes it seems that the tweeters can not be used anywhere lower than 6kHz, that's a mismatch with the PHL 1220. I will try them with my Phy-Hp's. Even if the tweeter would sound better I think they do not match very well together. At least I can see if the Yamaha's are more capable than what they are doing now.
 
Sjef said:
Salas: Thanks for your time and effort on the bessel array, defenitly gonna try that some day.

The frequency response of the NS1000 that you posted show the same HF roll-off as I measured on my tweeters, so they might be o.k. after all.

Yes it seems that the tweeters can not be used anywhere lower than 6kHz, that's a mismatch with the PHL 1220. I will try them with my Phy-Hp's. Even if the tweeter would sound better I think they do not match very well together. At least I can see if the Yamaha's are more capable than what they are doing now.

Please let us know what you finally come up with - & please post photos!

P.S. - can someone please tell me just what a Bessel Array is, and where I can find some info on it? If there were any links earlier in this thread I missed them. Thanks!
 
Ah, Bessel arrays. One of the great sacred cows of line array design. That doesn't mean they're not worth bothering with, just that you have to know what it is you're doing, and what you're hoping to achieve.

One of the problems with line arrays is that the vertical polar response of most is not so great (that's the polite version, though I will at this point admitt to being a fan of line arrays, and intend to build one when funds permit and I've completed my OB project). With a Bessel array, you wire the drivers so that the vertical size of the array appears to vary with the frequency. This is a particular problem at high[er] frequencies, because of the different distances the sound has to travel -short distance near the centre, further near the ends. There's a few ways you can create a Bessel array; the easiest way to get this sort of effect is probably to power-taper the line. However a point from the (useful) LDSG site, which is often forgotten:

"most references to Bessel arrays fail to mention that they're only effective at listening distances equal to, or greater than, approximately ten times the array length. This makes them unsuitable for most home application, although they're used to good effect in many stage and professional systems."

Not so good, especially because one of the principle objects and advantages of a home line array is to deliberately place the listener entirely in the near-field listening position, which is not exactly going to happen if you're sitting 10 times the line-length away from the blasted thing.

Still, I suspect that there is some truth in both views. Have a look at Jim Griffin's white paper on line arrays here: http://www.audiodiycentral.com/resource/pdf/nflawp.pdf

towards the end, you'll find a section on power-tapering and some wiring schematics for doing this. I doubt it'd be really worth the effort to power-taper the mid/bass array line, but at the very least it wouldn't do any harm to apply some to the tweeter line.
Cheers
Scott
 
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Very good summary indeed!
I only want to add that in a Bessel you have to phase invert some points too. A Bessel sounds spherical and I prefer it horizontal for tweeters. This way some rough edges can be driven up or down the useful vertical window. In the case of the one I proposed, you can find it 'geling' at over 2.2m, that is acceptable I believe in most domestic situations.
I think Macintosh does just that in their new speaker line.
I hope that the use of much radiating area and very low Fs (compared to a typical dome tweeter) will help our friend's situation.
As for in pro reinforcement sector I think that a Bessel can be very close to using physical waveguides. Meyer has some whitepapers showing that a linearray analysis in the end of the day reminds more of a constricted Bessel, and JBL stated (after a year of measuring in a leased arena their Vertecs) that the linearray speakers tend to have certain characteristics due to inherent dispersion control and not due to some cylindrical wave formation.
I have listened to this one which is a Bessel with some creative stuff in its controller so to cut the rough edges and it was good, doing the job without creative plumbing in the waveguides. Each speaker can play alone too and be double value to the installer who can lease em individually rather than having the system in the back of a lorry waiting for the next gig booking.
 

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Power tapering the tweeter line isn't overly difficult -it just involves connecting set groups of drivers together so as to create different loads. Ditto the mid/bass line if you want to try that as well. Perhaps not quite a 'true' Bessel array, but some similar results.
If you're thinking of building an Array, make sure Jim's White Paper is top of the reading list -really, it contains almost everything you need to know. However, I wouldn't pretend it's the easiest read on the planet... ;)
Cheers
Scott
 
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