Insane idea - Diatone P-610's in D'Appolito array + Raven R1???
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| Posted on April 29, 2000 at 22:59:02 | ||
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Dave VH 
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with crossover at 10 or 12KHz. Vented box. No phase/distortion problems with a crossover in the midrange, excellent high end with the ribbon that goes to 46KHz. Possible later integration with subs in enclosures below the speakers. Has anyone tried a design like this - a pair of full-range speakers (that actually roll off in the mid-teens) plus a super-tweeter? Dave van Harn
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| I have a similar idea, posted on April 30, 2000 at 07:15:45 | |
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Hi Dave I'm planning the same thing, but intend using the Babb P6 drivers, and not in a MTM, but a more conventional MMT. The reason for this is that the mid-points of the drivers, where the upper range of freq.s originate from may be too far apart in a MTM system, and, if nothing else, necessitate a distant listening position. The P6 drivers might not be so efficient, but I do believe that they ought to be better in every respect. BTW, I would like to couple them to the Raven R1 too, but since funds will be limited after I purchased them, I might opt for the Fostex FT-17H (until I can afford the Raven, that is). They are rated at 97.5 dB/W, and cover the range from 5k - 50k, and they are not too expensive at $37 each. You can find them on the Fostex Japan website. Look under 'Catalog' and go to 'Tweeter'. The problem with this arrangement is that the combined efficiency of two P6 drivers are only 91 dB/W at 4 Ohm (and that's only when the 8 Ohn version is released). If you're in a hurry, go for two pairs of the 1038 drivers, which are the 8 Ohm version of the 1034. According to Alan Babb they don't have the quality bass of the P6 (which is their cost-no-object design), but the combined efficiency of two 1038 drivers in parallel will be 101 dB/W at 4 Ohm. Or for just one per side it will be 95 dB/W at 8 Ohm. More details on these drivers can be found on their Technical Information page. Just my $0.02. Enjoy the DIY-ing (and the music). Deon
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| Re: I see an issue of balancing mid-range crossover distortion & HF beaming/integration., posted on April 30, 2000 at 13:07:04 | |
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I would use the Babbs fullrange (no XO to interfere with the sound) and put the XO at between 15k -20k. Alan Babb considers a tweeter to be totally unnecessary. If you want more information, have a look at the Full-Range Driver Forum. Also look in the archives. There is a LOT of useful information there. I can also send you a Word doc. of the e-mail correspondence that I have had with Alan. It is on hold at the moment because he is on a business trip, but I eagerly await to commence it when he returns. He is very helpful, and answers all and any questions posed to him as far as he can. If you want 65dB efficiency, why not try one pair of 1038 drivers in a TL, with the Raven on top. The TL could be short enough that you could put the Raven on top and time-align it. Alan says that the top-end of the 1038 drivers are the best in that range. I do know of one possible suitable driver, and that is the Cabasse 21M18. They come in a 16 Ohm version rated at 92 dB/W. BUT, and this is the big but, they only go as high as +- 3k, and one a pair of Cabasse drivers will cost you more than a pair of Babb 1038 drivers. And that is before the 15% discount Alan has offered everyone on the Full-Range Driver Forum, with the standard 30 money back satisfaction guarantee. I have been looking into a similar project for a while now, scouring the web for different types of drivers, etc., etc., and so far the Babbs have come the closest to what I want. I must admit that after speaking to Alan I feel confident in saying that unless high efficiency is an absolute priority (because you have a very low powered amp., or something like that), go for one or more pairs of P6 drivers. I think I am, even though I'm totally sold on the idea of high efficiency. Alan is currently investigating the possibility of a higher efficiency version of the P6, and he said that there would be a trade-in policy for owners of the current P6 version (or so I think I understood him). The reason for the low efficiency on the P6 is the gain-bandwidth principle. Alan wanted as wide a bandwidth as possible (in fact he says that they have a pair of P6 drivers, one per side, that measures flat to below 20Hz!!!). On top of that they managed to defeat heat losses, which can normally account for about 3dB - 6dB of compression. The P6 show NO compression loss. In fact he said they sometimes even show a 0.5 dB GAIN when things get hot. This is a very important consideration IMHO. Remember, this is a 6 dB loss over the normal steady state measurements, which puts the whole efficiency discussion in a totally new light. Much the same goes for the 1038 and others, as it is a proprietary design of the voice-coil (I think). BTW, regarding an 8 Ohm driver to match the Raven- the Raven is a 6 Ohm driver, so it will be easier to match to a 4 Ohm driver, as you only need a high-quality 24 Ohm resistor in parallel with the Raven to bring it down to 4 Ohm vs. a serie resistor to lift it to 8 Ohm. I still think a great combo would be the 1038 in a TL with the Raven on top. A pair in parallel could be used with something like the Fostex FT-96H, XO again between 15k - 20k, for a efficiency of +- 101 dB/W at 4 Ohm, and the Fostex providing extension up to 35k. Just my thoughts. Enjoy the music.
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| What Web Page Translator do you use??, posted on May 2, 2000 at 21:14:59 | |
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Dave VH
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I tried a couple, and they don;t work too well. Dave
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