ideas for this driver

[mjkempton]

Hey all

Suggestions for this driver please:

I have two stored away am getting an itch to box 'em up!

I had them in quarter waves a while back with good results, but reckon they could do better.

Nominal Diameter 25cm (10")
Power rating 300 Watts
Frequency range Up to 3.5 kHz
Nominal Impedance 8 or 16 Ohms
Sensitivity (1 W 1 M) 99 dB
Resonance 75 Hz
Enc. Vol. Recommended 3 to 60 Litres
Displacement limit 5 mm (0.20”)
Voice coil diameter 63.5 mm (2.5”)
Voice coil Copper
Voice coil winding depth 12 mm (0.48”)
Suspension (Spider) Fabric
Magnet gap depth 9 mm (0.36”)
Magnet material/mass 2.5 Kg (90 oz)
Magnetic assembly total mass 7.8 Kg (17.24 Lbs.)
Flux Density 15,000 Gauss
Cone type/material Curvilinear Smooth Paper
Surround Fabric

Fs 74.4 Hz
Xmax 1.5 mm
Revc 5.5 Ohms
Vd 4.5 x 10-5 m3
Qts 0.158
No 5.05%
Qms 4.43
Pmx 300 Watts
Qes 0.164
Cms 122 µM/N
Vas 20.78 Litres.
Mms 37.41 grams
Sd 346 sq cm
BL 24.21 T/m
Splo 99.05 dB

Much TIA

Jim

[el`Ol]

This is a simulation in a Zu Druid like ported short pipe. With floor loading you will probably get 5dB higher than this simu (old MJK ML-TQWT sheet)

[Geek]

With Q that low and SPL that high, sounds like horn fodder to me

[mjkempton]

Many thanks to el'Ol and Geek.

I'll run it through Martin's CAD sheet and see what squirts out.

Any more specifics on the horn idea Geek?

Jim

[moray james]

These look like a good candidate for a small sealed mid cabinet. The high efficiency (and hi BL) would suggest a qyality pro mid bass driver or as been suggested a a mid/bass horn. You might even ask Scottmoose to do a sim for a BIB as the Vas is very low but you still are not going to get much bass out of them as they were designed for mid/badd reproduction. Since they are only a ten inch driver the horn idea is not a first choice as it would work well but be larger than you might want and a 15 inch would be smaller in size (length). That brings us back to a small sealed cabinet which is exactly what i suspect these were designed for. Have a look at the Lansing Heritage site under "Daniel's System" where he uses such drivers for just this application.
A couple of these 18 inch bass drivers in a "W" dipolw could keep up and the overall size would match nicely then all you need to do is to choose a horn loaded tweeter to finisn off the system. These bass drivers represent about the cheapest bang for the buck I have yet found for moving lots of air for cheap. see http://www.mach5audio.com/product_in...4eeb788dd9d5b3
Regards Moray James.

[mjkempton]

Many thanks Moray.

My gut tells me a sealed cab would not be a good idea 'coz of the very short throw. Thoughts ?

I think I'll sim up a ML 1/4 wave and a reflex to get a better idea.

thanks guys

[moray james]

if the xmax of 1.5 mm is correct then the high Fs and high sensitivity of 99 db would suggest that a sealed box is what the doctor ordered. The sealed volume will insure a strong back spring action for the driver allowing the driver to play very loud with no fear of bottoming out or exceeding xmax. So lots of low distortion output. A vented box or TL would permit the driver to play lower and it would have little or no load near Fs and since you have limited xmax mor distortion and the posibility of the voice coil jumping out of the gap causing distortion. You will find that drivers designed to make bass at high levels most often have extended pole pieces to prevent the coil from jumping out of the gap on long excurssions. My guess is that this driver does not have this as it would look to have been specifically designed for either sealed box or horn loading neither of which will require the driver to move back and forth more than the 1.5 mm stated. Run some simulations and see what they show.
If you really want to make sure you could check with the manufacturer for their recommended style cabinet. From looking at the specs you posted they discribe a pro 10 inch driver designed for high output midrange applications not at all unlike the Beyma 10MI100. If you look at the specs for the Beyma you will see that while it is capable of plenty of travel for high peak output the xmax is given as only 2mm. The give away for this kind of application is the short coil length as compared to the top plate depth which in the case of the Beyma is 13.5 mm and 9.5mm. With you speaker the coil length is 12mm and the top plate thickness is 9mm. So given the high Fs of 75 Hz. it is a certainty that this driver was not intended for making much bass. You can ask it to but it will not be well suited and you will probably fry the coil as it will be spending too much time out of the gap and so will not be able to sink enough of the heat build up to either the top plate or the pole. So if you want it to make some bass for you a big horn is about your only realistic hope.
I am no expert at this but if there is anybody who is perhaps they can comment on your realistic options for a driver with these parameters. Best regards Moray james.