Hi guys,
Need some help.
I want to build some speakers based on the beyma 15xa38nd coaxial drivers.
No extra tweeters or woofers. Just the beyma's. A bit like the old tannoy's.
What i need are some plans for the enclosures. (And some crossover schematics, if there are any)
I prefer mltl, tqwt or ported boxes.
If possible, could someone hook me up with some plans?
Hope someone can help me.
Sent with tapatalk from a lazy chair......
Need some help.
I want to build some speakers based on the beyma 15xa38nd coaxial drivers.
No extra tweeters or woofers. Just the beyma's. A bit like the old tannoy's.
What i need are some plans for the enclosures. (And some crossover schematics, if there are any)
I prefer mltl, tqwt or ported boxes.
If possible, could someone hook me up with some plans?
Hope someone can help me.
Sent with tapatalk from a lazy chair......
Greets!
I neither do drawings, just provide basic dimensions, nor design XOs, so tweaking the stock one is all I can recommend.
For cab alignments, what are your room dimensions and where they will be located, listening distance [Lp], max physical cab dimensions, average seated ear height and are you open to maybe having the driver somewhat above it if there’s no cab height restrictions?
Also, what type electronics will drive these and if tube, then ideally need its output impedance [series resistance, not tap value unless it’s a matching impedance amp with a damping factor [DF] = 1.0].
GM
I neither do drawings, just provide basic dimensions, nor design XOs, so tweaking the stock one is all I can recommend.
For cab alignments, what are your room dimensions and where they will be located, listening distance [Lp], max physical cab dimensions, average seated ear height and are you open to maybe having the driver somewhat above it if there’s no cab height restrictions?
Also, what type electronics will drive these and if tube, then ideally need its output impedance [series resistance, not tap value unless it’s a matching impedance amp with a damping factor [DF] = 1.0].
GM
My room is about 4.5 x 7.5 m. Maximum height would be about 1 m (maybe little more) and about 50 cm width and depth.
I want to use a (diy) pass aleph 3 . 30w class a. Would be serious overkill i think.
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I want to use a (diy) pass aleph 3 . 30w class a. Would be serious overkill i think.
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I found a grf cabinet plan for the beyma's.. is that a good enclosure for it?
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The GRF is a back loaded horn, so odds are the Beyma's specs are not compatible, but will need the driver specs it was designed for to be sure.
GM
GM
it would "work" with the original Karlson K15 - you might use it in a straight MLTL too http://img825.imageshack.us/img825/5469/k15k.png
That's a nice driver. 99dB, 0.29Qts, 4mm xmax, 2in coax CD, Nd magnets, 350watts program. Wow must cost some change.
http://www.beyma.com/getpdf.php?pid=15XA38Nd
I agree that Karlson K15 would be a very effective cabinet that would be very matched and knock you out of your socks at full power.
For deeper bass extension, maybe an XKi?
http://www.beyma.com/getpdf.php?pid=15XA38Nd
I agree that Karlson K15 would be a very effective cabinet that would be very matched and knock you out of your socks at full power.
For deeper bass extension, maybe an XKi?
Thanks freddi !
Going to take a look at this.
My wife agrees with the dimensions .[emoji16]
Always helps.
Don't read many positive reactions on these cabinets though...
Looking for some in home enclosures. Best possible sound.
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Last edited:
GM: Freddi posted the driverspecs.
On this site the grf for the beyma's are posted: http://forum.speakerplans.com/15-scoop-like-rectangular-tannoy-grf_topic90924.html
As you can read he modified the horn. But if this is a good one.... i don't know.
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On this site the grf for the beyma's are posted: http://forum.speakerplans.com/15-scoop-like-rectangular-tannoy-grf_topic90924.html
As you can read he modified the horn. But if this is a good one.... i don't know.
Sent with tapatalk from a lazy chair......
Also found these on the web.
(The two small pieces are braces?) Would thesecabs be a good option for the beyma's?
Sent with tapatalk from a lazy chair......
(The two small pieces are braces?) Would thesecabs be a good option for the beyma's?
Sent with tapatalk from a lazy chair......
Also found these on the web.
(The two small pieces are braces?) Would thesecabs be a good option for the beyma's?
Sent with tapatalk from a lazy chair......
This is a TQWT with mass loaded constriction. Was this one designed specifically for the Beyma?
OK, so ~7 ft^3/~198.2 L [net], theoretically somewhat small for a reflex or [ML]TL tuned to Fs unless corner loaded, but the latter is a bit better performing overall.
The amp has a very low output impedance, so not an issue, though 30 W is hardly ‘overkill’ if any of your music has decent dynamics, with a minimum 130 W required to replicate some symphonic CDs at high sound quality [SQ], i.e. without clipping the amp.
GM
Hmm, maybe if it was a duplex design [separate HF horn], but basic co-ax? Too much mids/lower HF is 'trapped'/distorted in the front chamber IME and for sure it wouldn't have any deep bass since it's optimized for a strong mid-bass, lower mids.
Yeah, not many drivers that can't be made to perform well in a [ML]TL if large, long enough to allow for plenty of fine tuning flexibility.
On a side note, to make the ‘K’ a good option for point source ‘FR’ drivers and its co-ax variants, the slot profile needs to be rethought/designed to closer mimic a compression horn driver’s phase plug.
GM
Where? I don't recall ever seeing what driver specs were used to design the GRF.
Regardless, the fact that someone felt the need to only use it as a 'starting point' for the Beyma confirms it wouldn't be a good enough choice to try and empirically tweak it to suit your desired performance goals.
I barely have time to browse/post these days, consequently don’t have time to do any horn reverse engineering anytime soon unless all the salient path-lengths, horn area expansions, filter chamber net volume [Vb] is published, though the fact that the designer wants to change it strongly suggests you might not be pleased with it overall, at least not long term, so 'caveat emptor'.
GM
Correct.
Only an OK option IME since this ‘TQWT’ [or more appropriately referred to as a [ML] horn in today’s lexicon] works better with higher Qts drivers whereas the Beyma’s relatively low Qts is better suited to an inverse tapered TQWT since it more closely mimics the relatively small cab net Vb and long, large area vent it requires to have a low vent mach at high SPL.
Overall then, currently lacking a proven, optimized horn design for this driver, the latter is the only ‘proven’ vented cab alignment option beyond a basic T/S optimized reflex IME.
GM