Best Compression Drivers today 2022?

I made a post 15 yrs ago about chamber resonances on AudioAssylum for the BMS 4592nd regarding connected chambers and blocking them with a washer.
There is a chamber for the speaker terminal that pokes through into a driver chamber and blocking it off hade a small but perceivable difference
on my BD horns. Many golden ears felt it was on par with the TAD. It is good to see the BMS units still to date scoring high.

https://db.audioasylum.com/mhtml/m.....mpl?author=alon5rev3&forum=ALL&sortRank=None
 
Takes me straight to it. I'll cut and paste but no pics anymore .
The 4592nd only shines when you modify the driver. There is a machined hole in the throat that wreaks havoc with the sound. Dave Adams (Electron-Luv) was here and said the modified driver sounded easily as good or possibly even better than the TAD in one of Kevins horns.
BTW I have an Azura flare 350hz horn. I should post the mod as I took photos as I was doing it. The factory crossover totally blows.

RE: I would love to hear more about the BMS mod!​

Ok. the best way to understand the mod is to remove the tweeter. That is very easy to do and you will see the recess that BMS machines into the housing to clear the solder joint for the tweeter leadouts. The problem is that it goes clear through into the compression chamber for the mid.
I used a stainless disk that fit in the recess and epoxied it in. Then place 2 sheets of heavy paper over the disk to insulate it. I also tapped the solder on the tweeter leadouts down so it will not protrude into the paper insulator. It removes a nasal peak in the response and it sounds smoother overall. Look for pics over the weekend.
Bob
 
https://reconingspeakers.com/products-page/jbl-horn-lens-5006815-stx825/ no EQ is needed, good to below 1500hz, I cross at 1500 .And have used a B&C ME 90 clone with good results.

Personally I quite like the JBL #5006219 (70° × 70° nominal).

1688620363810.png


If you look at the shaded area in the mouth (towards the throat) you get an idea of the polar response.
The knuckles limit the horizontal expansion of the wavefront, while the vertical planes resemble a radial horn.


JBL STX812M:

STX812M-front-nogrill.jpg1688621808153.png
 
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The 5006815 is 1.5" JBL uses it with a CD with 4" diaphragm. The 2431 I'm using is 3" diaphragm.
Hello,

The JBL 5006815 PT wave guide is 90 X 50, I sometimes us it on top of my large speaker stack.

I use the JBL 5006815 WG with the D2 D2430H compression driver. The dual diaphragm driver is smoother to me than the other choices.

The phase plot has like 3 peaks, typical of many horns. The saw tooth plot is normal for horns and CD's. The plot has no curve fitting and smoothing turned off. The top octave is much smoother than the other choices. N ripples at the top end. The Voice Coils are wired in parallelThe dual diaphragms do not breakup like the 3 and 4 inch diaphragms do.

Thanks DT

Impedance Magnitude M2430H PT 90 X 50.png



This may be easier on the eyes. 1/12 octave smoothing.

Impedance Magnitude -_ Smooth JBL D2430H.PNG
 
my custom M2 use RCF 2inch driver and a lot of wood

Very nice setup, are you happy with the HF? Seems you are bi-amping, if yes, how are you doing your XO, active or DSP?

I friend wants to build a HE 2/3-way and we have been thinking of mating the RCFs in the 1.4" version (or the SBA 65CDN-T) @ ~700Hz to a Precision Devices PD.152.002 (some other interesting options from PD too, like the PD153ER):

PD.152.002

Fs 38 Hz
Re 5.6 Ω
Qms 4.03
Qes 0.265
Qts 0.249
Le (@ 1 kHz) 1.28 mH
Vas 263 Litres
Mms 67.14 g
Sd 853 cm2
Cms 254.40 μm/N
BL 18.90 T/m
Xmax 6.75 mm
 
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the Hashimoto amps have an amorphous Monolith magnetic output transfo and interstage , but i can't use it for the moment as it have too much gain , so i use the smaller one with only a lundhal stepup transformer and a 300B with a Tango output transformer . ( Sakuma copy ) for the carpet i think there is no way it can happen one day 😊 all the amps and electronic are not direct on glass but on sobothane feets ..