Midbass horn

[freddi]

here's an old in-room graph of a "small" 150Hz tractrix given to me by Bruce Edgar loaded with an Eminence Beta8cx with Eminence CD8 (aluminum diaphragm) compression driver and an Eminence 1K6 ("textbook") crossover - there's no highpass - unfortunately I didn't measure it with a highpass/bandpass on the cone driver to see what could be done nor its performance with a 6.5" Audax as the flat foam surround had started to rot on the latter;

An externally hosted image should be here but it was not working when we last tested it.

 

[Phenoholic Anonymus]

Does anybody have a suggestion for an affordable 10 or 12 inch horndriver? Qes < .33, Fs > 55, x-max not of importance. Maybe in the guitar, bass department? Good horndrivers seem to be scarce.

 

[norman bates]

price range ?

 

[winslow]

And application

 

[Phenoholic Anonymus]

Around 100$ would be nice. Sadly, we can have some Beta Three / Elder Audio drivers in Europe through Thomann. But the extremly well horn driver 10LB075-8M is unobtanium : ( I found the most usefull drivers at very obscure places. MAG audio, Sica...

 

[tinitus]

Maybe in the guitar, bass department?

I thought a good horn driver would have low Qts

I fear the very cheap driver have too high distortion

what size is optimal ?

 

[Phenoholic Anonymus]

There are some very low Qes guitar speakers with extremly stiff suspension

 

[POOH]

Used EV EVM12L normally are around 100 US - decent driver - The larger EVM 15L or 15B are two of the best midbass horn drivers I've found. The 15 is more efficient, goes lower and higher in a horn and is more linear.

 

[tinitus]

am I right that a midbass horn tend to get smaller using bigger drivers ?

 

[winslow]

Thats right.

 

[unaHm]

Just found this!

MCM Audio Select 12" Woofer with Paper Cone and Cloth Surround - 175W RMS at 8ohm | 55-2952 (552952) | MCM Audio Select

Thiele-Small Parameters:

• Resonance Frequency Fs: 38 Hz
• DC Resistance Re: 7.2 ohm
• Mechanical Q Factor Qms: 2.8
• Electrical Q Factor Qes: 0.385
• Total Q Factor Qts: 0.34
• Equivalent Cas air load Vas: 108.0 liters
• Coil Inductance Le: 0.923 mH
• Efficiency Bandwidth Product EBP 98.70
• Voice Coil Over Hang X-max 3.75mm

Close?

Also:

http://www.mcmelectronics.com/product/MCM-AUDIO-SELECT-55-1220-/55-1220

Specifications::
Power Capacity: 100W/200W RMS/peak
Sensitivity: 98dB (W/M)
Impedance: 8ohm
Re: 6.8ohm
Le: 2.15mH
Frequency response: 26Hz~3KHz
Fs: 26Hz
Qts: 0.30
Qes: 0.34
Qms: 2.33
Vas: 175.88 (liters)
Xmax: 2.25mm

 

[freddi]

re:55-2952 - real parameters:
http://www.diyaudio.com/forums/subwoofers/211646-bang-buck-18-15-subs-2.html#post3067064

dunno who has real horn drivers cheap - I use 12pe32 in a little Karlson - its not cheap

 

[winslow]

fwiw the ev evm15l and and 15b have been dr edgar's midbass of choice for over a decade in his titan 80 hertz horns. good to 500 hertz on the top side.

 

[winslow]

also see what jlh has used. john is pretty sharp with horns. one time he liked the fane studio 8 and beyma 8mi100.

 

[Phenoholic Anonymus]

This is my list sofar of suitable 10 inch drivers. In order of 2x Fs/ Qes mass roll off point:
[FONT=Arial, sans-serif]
Beyma 10Mi100/ 712 Hz[/FONT]
[FONT=Arial, sans-serif]B&C 10MD26/ 610 Hz[/FONT]
[FONT=Arial, sans-serif]B&C 10MD26/ 610 Hz[/FONT]
[FONT=Arial, sans-serif]DAS audio 10B/ 607 Hz [/FONT]
[FONT=Arial, sans-serif]Precison Devices D.107/ 576 Hz[/FONT]
[FONT=Arial, sans-serif]18 Sound 10M600/ 560 Hz
RCF L10/L750YK/ 544 Hz[/FONT]
[FONT=Arial, sans-serif]Beta Three 10LB075-8M/ 538 Hz
[/FONT][FONT=Arial, sans-serif] Ciare PW 256/ 530 Hz[/FONT]
[FONT=Arial, sans-serif]MAG Audio M1021/ 529 Hz
KAPPA-10A PRO/ 520 Hz
B&C 10PLB76/ 505 Hz[/FONT]
[FONT=Arial, sans-serif]18 Sound 10MB600/ 504 Hz[/FONT]
[FONT=Arial, sans-serif]B&C 10FW64/ 504 Hz
Sica 10F2.5CP/ 388 Hz[/FONT]
[FONT=Arial, sans-serif][FONT=Arial, sans-serif]MAG M1040/ 356 Hz
[/FONT] Sica 10E2CS/ 333 Hz [/FONT]

There is no judgement on actual (measured) Qes, x-max, Rms. Availability or price. Although no driver in this list is above +- 220$ from where my shopping cart is placed.

Some other diameter examples of good or famous horn drivers.
[FONT=Arial, sans-serif]6 inch B&C 6MDN44/ 634 Hz[/FONT]
[FONT=Arial, sans-serif]8 inch B&C 8PE21/ 734 Hz [/FONT]
[FONT=Arial, sans-serif]12 inch EVM 12L/ 449 Hz [/FONT][FONT=Arial, sans-serif]
15 inch Klipsch KE33/ 168 Hz
15 inch EVM 15L/ 344 Hz
15 Inch Vitavox AK 151/ 333 Hz
[/FONT]

 

[Phenoholic Anonymus]

In a horn these drivers will barely move at 90dB/ meter. So i tend to be overly worried about Rms / suspension loses. Probaby going Sica 10E2CS = 0.7 Rms works ok upto 500Hz if you use the "good to about half an octave above mass roll off" guideline.

 

[tinitus]

how about using two smaller drivers in parallel ?

 

[POOH]

fwiw the ev evm15l and and 15b have been dr edgar's midbass of choice for over a decade in his titan 80 hertz horns. good to 500 hertz on the top side.

That's in a folded horn - 15l goes to 3k in my 70 Hz hypex straight horn

 

[Phenoholic Anonymus]

Tinitus, i have tought of using two smaller drivers. Would be wonderfull if we could find two suitable 16 Ohm drivers. Especially in a impulse compensation setup. Where the movements of both drivers on the enclosure cancel each other out.

 

[tinitus]

not sure I would use folded design above 150hz

I was thinking waveguide type, and more like this