hifi midrange 100-1500 Hz, classical 6.5'' or PA 12'' ??

[mbon]

I'm looking for a good midrange driver to match a compression B&C DE25 @1.5kHz, I've got the advice to use B&C 12PL32 wich is high efficiency driver and flat from 100 to 1500 Hz but its Mms is 42g for a Bl of 16.1 T.m, this frequency range is critical for my favourite instrument wich is piano, distorsion should be low with such a driver but how to predict accuracy compared to a 6.5'' classical hi fi driver like Focal, SEAS excel or scanspeak ????


Any advice, opinions ?

[mikee12345]

hello!

Audio legend # 1
'large woofers are slow'

I would be more interested in such things as
-Dispersion(particurly when considering a 12" going near 1khz)
-Frequency range
-harmonic distortion
-TIMD etc etc
-energy storage


http://www.mfk-projects.com/the_6_in_comparison.htm
the linkwitzlab.com site did have some midrange speaker measurements and comparations.

[mbon]

Originally posted by mikee12345
hello!

Audio legend # 1
'large woofers are slow'

I would be more interested in such things as
-Dispersion(particurly when considering a 12" going near 1khz)
-Frequency range
-harmonic distortion
-TIMD etc etc
-energy storage


http://www.mfk-projects.com/the_6_in_comparison.htm
the linkwitzlab.com site did have some midrange speaker measurements and comparations.

Yes, dispersion, frequency range, waterfall, harmonic distorsion, energy storage, all those criteria are essential, so :

*dispersion : little woofer seems better than large one
*freq. range : 12'' woofer like B&C12PL32 can reach 1.5kHz with flat freq. response
*waterfall : no man's land, so hard to get some information about ir
*harmonic distorsion : I don't know wich is the best, I think 12'' drivers is better than a 6.5'' one in the 100Hz region and 6.5'' is better in the 1.5kHz region ?
*energy storage : a 12'' like B&C 12PL32 is about 98 dB efficient between 100 and 1500 Hz, it is an heavy cone but with the large motor, is it an issue ? I don't think a 6.5'' woofer has more energy and dynamics ...


So, what is the advice ? I plan to use a Beyma 15K200 for the low bass (< 100-150 Hz) a woofer up to 1.5kHz and a compression driver B&C25 up to 18Kz

[BillFitzmaurice]

A twelve is going to beam from 1kHz at best, but a 6.5 isn't going to have what it takes to keep up with the HF element. Go with a high sensitivity 8 or ten, but make sure you have an XMax of no less than 3mm or you'll get power compression in the lower range. Raw frequency response of a pro-sound 12 is going to look fine up to 3kHz at least, until you check the response at 30 degrees off-axis. That is the frequency response you want to look at.

As to the term 'slow', remove it from your loudspeaker vocabularly. A driver cone moves at the 'speed', more properly referred to as frequency, of the signal fed to it by the amp. The driver itself has no contribution regarding how fast the cone moves.

Make sure you run a sim before deciding on the woofer. If that Beyma you're considering is a pro-sound model it may not be much good below 50 Hz, but on the other hand will work well to at least 300 Hz in the mid-bass.

[mbon]

Originally posted by BillFitzmaurice
A twelve is going to beam from 1kHz at best, but a 6.5 isn't going to have what it takes to keep up with the HF element. Go with a high sensitivity 8 or ten, but make sure you have an XMax of no less than 3mm or you'll get power compression in the lower range. Raw frequency response of a pro-sound 12 is going to look fine up to 3kHz at least, until you check the response at 30 degrees off-axis. That is the frequency response you want to look at.

As to the term 'slow', remove it from your loudspeaker vocabularly. A driver cone moves at the 'speed', more properly referred to as frequency, of the signal fed to it by the amp. The driver itself has no contribution regarding how fast the cone moves.

Make sure you run a sim before deciding on the woofer. If that Beyma you're considering is a pro-sound model it may not be much good below 50 Hz, but on the other hand will work well to at least 300 Hz in the mid-bass.

That's correct, more large is the cone, more the off axis is falling at 30°, you seem to think that this 12'' driver is not a good idea for my project and than a good 8'' or 10'' driver with enough Xmax and low distorsion is a better choice ?
Wich 10'' driver ??? It's for a Hi Fi system with high efficiency driver...

[wunhuanglo]

I'd be looking here http://www.phlaudio.com/main.html

[pinkmouse]

What is your price range?

You might want to look at the Volt BM251.4 , or the Precision devices PD102, both very nice 10" drivers

[BillFitzmaurice]

I can't recommend what you may not have available to you. I'd look at specs of Spl 96 to 100 dB, Fs 60 to 90 Hz, Qts .25 to .4, XMax at least 3mm and no more than -6dB at 30 degrees off-axis at your intended crossover to the HF element. Go with a lower Qts with a low Fs, higher Qts with high Fs. Model it in WinISD to be sure of an acceptable F3 and box size.

[forsythe]

I also would be concerned with the amount of cone flex the 12" driver driver will exhibit at 1.5 kHz. Operation of the 12" driver at 1.5 kHz will be less pison-like than a 6.5" or 8" driver made with the same cone material. Hence, I would expect the 12" driver to generate more distortion.

[mbon]

Originally posted by forsythe
I also would be concerned with the amount of cone flex the 12" driver driver will exhibit at 1.5 kHz. Operation of the 12" driver at 1.5 kHz will be less pison-like than a 6.5" or 8" driver made with the same cone material. Hence, I would expect the 12" driver to generate more distortion.

I think you're right, I'm going to buy the Beyma 6MI90, it seems to be enough for my project wich is "make high quality music" in the living room.

so go for Beyma 15K200+6MI90+B&C DE25 and ME45 HORN


just for the fun, this is my first PA/Hi fi speaker

maybe two units of 6MI90 for a d'appolito choice is an option, so efficiency of midrange reach bass and reduce distance to the 108 db/W/m of the compresison driver.
But I use 16Watts class A power amp so two 6MI90 may be hard to drive...