DX2 & Eminence 15" OB

[britbug]

I am thinking of doing a hybrid of the MJK open baffle projects that have received attention.
A Lowther DX 2, beefed up in the base with an Eminence Alpha 15 " combo, and crossed passively.
Does anyone know if :
2 15" per side will be enough, and whether I should use U or H frame on one or both?
Should I parallel or series the woofers?
ta

g

[Scottmoose]

How much is 'enough?' Not being awkward, just that it's something of a variable point so it's difficult to answer without more specific information.

[britbug]

I guess what I mean is make sure it is not bass-deficient in comparison to the > 200Hz of the DX2 (which is pretty efficient).

I can pad down the lowther a bit to suit (more than 2 woofers per side will make for a big speaker) but don't want to lose too much of their sensitivity either.

Good Q

[Taterworks]

You'll probably gain a good bit of flexibility by multi-amping, with a separate amp for your woofers. That's really the way you should go -- otherwise level-matching will be more difficult, and require more sophisticated math. If you multi-amp, you'll be able to just tweak it until it 'sounds right'.

[MJK]

I did some quick numbers (less than 5 minutes invested) and found that a Lowther DX2 with a pair of Alpha 15A woofers per side would work in a reasonably sized (24" x 48") baffle with a passive crossover. You would get a system with 95.5 dB/w/m efficiency down to 50 Hz where it would roll off at 18 dB/octave. If done right this could be a real interesting passive OB system.


A U frame or H frame could be used to extend the bass lower but you would need to pad down the Lowther so the final system would loss a few dB in efficiency. I would stick with the simple OB geometry.

Hope that helps,

[ronc]

I have been running some sims on cuved U frames(vert curve) for OB applications using my curved mouth exit on horns programming. Its more of a tuning effect(think rear waveguide) with no resonance effect.
This was done for the accomplishment of the BVR/OB combo. Scott led me into the BVR application and i have been doing a study into the actions for various driver applications. Its interesting as there is no TL acton involved so the final action is an expansion of BR BW with a slight greater loading of the driver over a BR application (horn loading).

ron

[thomaseliot]

What about this baffle?



Mods:

1 - Bi-Amping

2 - Active filters (or digital filters from PC)

3 - 8" Fullrange high sensitivity (I have a couple spare FE206) instead of the Seas 90 dB mid driver

4 - 2 pairs of Alpha

5 - (optional) a pair of high efficiency compression drivers (B&C DE250?)

Target would be very high SPL at listening position. Would the Alpha be enough?

[DaveCan]

[i]Originally posted by thomaseliot [/i

Target would be very high SPL at listening position. Would the Alpha be enough? [/B]

Very high SPL's at the listening position is not a good idea for your hearing if your wanting to enjoy music for the years to come etc..
Dave

[ttan98]

Originally posted by DaveCan


Very high SPL's at the listening position is not a good idea for your hearing if your wanting to enjoy music for the years to come etc..
Dave

speakers with high spl is ok, you don't have turn the amplifier way up, listen at low level is still ok!

[DaveCan]

Originally posted by ttan98



speakers with high spl is ok, you don't have turn the amplifier way up, listen at low level is still ok!

Yep, I know that... Just made the comment because his ''Target'' is very high spl's at the listening position, and unless your wanting to fry your hearing??? Dave