Beyma...Beyma...Beyma
Clean...Clean...Clean
dave123, Very nice build.
--Are you using passive crossovers, or active slopes generated in your 6-channel preamp? (Brunel preamp info is down)
--The pure resistance of the TLP-150H membrane allows a perfect LR4 slope around your 1600-1750Hz crossover points.
--Using three stereo power amps is a very good way to balance SPL between drivers, with either active front-end Xovers, or passive on-driver Xovers. With a single amplifier a pair of 18" woofers are required to match the 12P80ND SPL/watt efficiency, and provide 220Hz crossover with baffle-step compensation.
--Your ears will be pleased after reducing edge diffraction with 1.5" radius router bit.
----You can buy 2"-6" radius MDF corners. Many cabinet shops can cut 3" radius rounds.
--Mounting the TPL-150H very close to the 12P80Nd can provide some reduction in lobing.
--Constructing a tapered sealed volume (simple triangle top+bottom boards) with rear stuffing behind the 12P80Nd can reduce resonances over the very wide BW.
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Has anyone accurately measured the time delay difference between the 12P80Nd_v2 and TPL-150H? Physical drawings suggest close time match.
Clean...Clean...Clean
dave123, Very nice build.
--Are you using passive crossovers, or active slopes generated in your 6-channel preamp? (Brunel preamp info is down)
--The pure resistance of the TLP-150H membrane allows a perfect LR4 slope around your 1600-1750Hz crossover points.
--Using three stereo power amps is a very good way to balance SPL between drivers, with either active front-end Xovers, or passive on-driver Xovers. With a single amplifier a pair of 18" woofers are required to match the 12P80ND SPL/watt efficiency, and provide 220Hz crossover with baffle-step compensation.
--Your ears will be pleased after reducing edge diffraction with 1.5" radius router bit.
----You can buy 2"-6" radius MDF corners. Many cabinet shops can cut 3" radius rounds.
--Mounting the TPL-150H very close to the 12P80Nd can provide some reduction in lobing.
--Constructing a tapered sealed volume (simple triangle top+bottom boards) with rear stuffing behind the 12P80Nd can reduce resonances over the very wide BW.
==========
Has anyone accurately measured the time delay difference between the 12P80Nd_v2 and TPL-150H? Physical drawings suggest close time match.
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But voila, re listened the Ravel's Boléro today... hummm liten to the last minute in a good live reccording
I would like to ask if you can listen the piano transition from 5th octave to 6th octave, for me is audible the distortion increment front TPL150 to 12g40, Piano in 6th octave is delicious on TPL but 5th on 12g40 is not my cup of tea.
all 12 inch have in this transition the 3rd Harmonic too high over TPL
Keep in mind the 12p80nd is a midrange driver while the 12g40 is a bass driver. I have dual 10g40 and like them, but for bass. Heavy for midrange.
Beyma calls the 12p80nd a "low frequency transducer"....
With its moving mass of 67 grams and serious beaming at frequencies higher than 1300 Hz I am a bit puzzled that people seem to like them partnered with the TPL150H.
IMO this is not a dedicated midrange speaker.
8 inch is about the limit for a real midrange driver; I compared Audax HM210Z10 with B&C 8PE21, and despite the very low Qts of the latter it partners very well with hornless TPL150 (crossover 1900 Hz).
With its moving mass of 67 grams and serious beaming at frequencies higher than 1300 Hz I am a bit puzzled that people seem to like them partnered with the TPL150H.
IMO this is not a dedicated midrange speaker.
8 inch is about the limit for a real midrange driver; I compared Audax HM210Z10 with B&C 8PE21, and despite the very low Qts of the latter it partners very well with hornless TPL150 (crossover 1900 Hz).
I don't notice a 600 Hz roll off.
It is used from 300 Hz in a damped but open enclosure and covers almost 3 octaves up to the TPL150.
Faitalpro 15pr400 for bass.
B&C 8PE21 is well known for mid bass duty when horn loaded, but as a direct midrange radiator it is the best I have heard until now as a combo with TPL150.
It is used from 300 Hz in a damped but open enclosure and covers almost 3 octaves up to the TPL150.
Faitalpro 15pr400 for bass.
B&C 8PE21 is well known for mid bass duty when horn loaded, but as a direct midrange radiator it is the best I have heard until now as a combo with TPL150.
While I don't have hands-on experience, I'very come to the same conclusion regarding 8" being as big as I'd want to go. Maybe 10" with a TD10M and its curvilinear profile.
Very good to know you were able to compare HM210Z10 and 8pe21 paired with TPL and preferred the 8PE21.
Do you feel the TPL or the 8pe21 was the limiting factor in setting the 1900Hz xo point? Active or passive xo? Slope?
Thanks for sharing this!
The speaker is not finished yet.
In a prototype I compared the Audax with the B&C. Despite the good specifications of the Audax it was difficult to correct it's rising response without loosing too much efficiency; it had too much of a "cuppy" character whereas the 8PE21 immediately blended well with the TPL150 with a neutral sound, not "lagging" behind the TPL150 in terms of speed (the large magnet and high Bl might have something to do with this).
When the bass enclosures are ready the system as a whole will be finished, maybe separate amplification for the bass speaker.
In the prototype the 8PE21 had a pretty wide baffle (some 45 cm); crossover LR2 at some 1900 Hz but this will be rechecked and optimized. Not lower though because TPL150 looses sound quality when crossed lower.
In a prototype I compared the Audax with the B&C. Despite the good specifications of the Audax it was difficult to correct it's rising response without loosing too much efficiency; it had too much of a "cuppy" character whereas the 8PE21 immediately blended well with the TPL150 with a neutral sound, not "lagging" behind the TPL150 in terms of speed (the large magnet and high Bl might have something to do with this).
When the bass enclosures are ready the system as a whole will be finished, maybe separate amplification for the bass speaker.
In the prototype the 8PE21 had a pretty wide baffle (some 45 cm); crossover LR2 at some 1900 Hz but this will be rechecked and optimized. Not lower though because TPL150 looses sound quality when crossed lower.
anyone knows the 18's Sound 6ND410 ? 700 Hz to 2000/2100 Hz for the TPL150H and below the Beymas 10g40 ?
http://www.eighteensound.com/Portals/0/PDFs/6ND410.PDF
http://www.eighteensound.com/Portals/0/PDFs/6ND410.PDF
..this doesn't sound right. The Audax should have *easily* surpassed the B&C.
In a good design it doesn't span much bandwidth. The upper end should be high-passed at a lower freq. (..perhaps 1.4 kHz). And the lower end should be supported by baffle diffraction to about 500 Hz with its own natural roll-off from there (..and if you need high spl's then put an added high-pass filter further down in freq.).
The rear chamber should be large and *deep* (I like cardboard tubes) without any resistance, or perhaps with a very low freq. tuned port (..not for any pressure increase at lower freq.s, but rather to provide the right kind of resistance to the driver at it's own resonance). Finally, it should have an impedance filter on the driver's resonance (in-box).
10" cardboard tube for concrete forms should work well - and perhaps 45 centimeters length. No stuffing.
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That's what I presumed also, and the Audax was the first choice.
But as it would need more attention to get it well together with the TPL150, I tried the 8PE21 next because the units could easily be switched.
Though the filters most likely were not optimized the combination already sounded very good; TPL150 and 8PE21 obviously like each other.
When bass units are done I'll give the Audax a second chance.
..If you do try it again, please try it as "outlined" above.
Added resistance to driver motion of this type just kills the depth of field and overall auditory scene expansion. This generally means a much larger volume than normal and particularly reducing as much air-flow resistance as possible (..aperiodic designs are particularly bad - especially when coupled with a small volume).
Getting the diffraction "signature" right should allow a fairly linear response down to that diffraction "peak".
Added resistance to driver motion of this type just kills the depth of field and overall auditory scene expansion. This generally means a much larger volume than normal and particularly reducing as much air-flow resistance as possible (..aperiodic designs are particularly bad - especially when coupled with a small volume).
Getting the diffraction "signature" right should allow a fairly linear response down to that diffraction "peak".
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Ok.. that's probably a problem with regard to the freq. response and the rising response..
(..it's almost designed like old Scan-speak drivers with the expectation of being in a narrow baffle to combine with the diffraction signature of a narrow baffle.)
..the "cupped" quality was probably from a low-pass to high in freq..
(..Still, I don't get that quality with my 6" Z0..though it is smaller in diameter, and a bit more "shallow" in diaphragm depth.)
(..it's almost designed like old Scan-speak drivers with the expectation of being in a narrow baffle to combine with the diffraction signature of a narrow baffle.)
..the "cupped" quality was probably from a low-pass to high in freq..
(..Still, I don't get that quality with my 6" Z0..though it is smaller in diameter, and a bit more "shallow" in diaphragm depth.)
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PR 170zo
Hey [other] Scott,
I'd be interested in seeing how you have those 6inch ZO's implemented into your system !
Hey [other] Scott,
I'd be interested in seeing how you have those 6inch ZO's implemented into your system !
Scott,
Honest question: why are you thinking the Audax should have easily surpassed the 8pe21? Have you tried both as midranges?