[drongo]

I too have just built a pair of MJK open baffles. My implementation has used Lowther DX3s, Alpha 15s and miniDSP as an active crossover. I drive the DX3s with a Trends T-amp and the Alphas with my old Rotel 40 watt amp (a little small I know but just fine my for modest volume needs) I used Martin's crossover points of 200 and 400Hz and no equalisation.

Result: fantastic - if you're reading this you've probably read the other posts about MJKs OBs - they're all true. I was in the fortunate position to already own a pair of DX3s, however I'm sure any one of many other wide rangers would fit the bill.

I would recommend the miniDSP - it gives you the choice to run the driver of your choice and its a breeze to configure.

Just a note on the bass sound - it is articulate, sounds like about 40hz and its a "big natural" sound.  "Normal" 6 - 7inch polypropylene midbass units (to my ears) have a more "authoritative drier slam" - not bad but different.

I'm very happy with these - I can't imagine building anything better.

[MJK]

Thank you for the positive feedback, it is greatly appreciated.

The Eminence Alpha 15A is a very flexible and easy driver to integrate into a dipole speaker system. It can be paired up with drivers costing may times more and still hold its own producing very solid bass support.

Enjoy,

Martin

[Squidspeak]

Martin, Do you feel that the Dayton driver PA380 15" driver would be a suitable substitute for
the Alpha 15A for OB bass duty?

[MJK]

The fs and Qts are both much lower then the Alpha 15A. So not a drop in replacement, it will need a lot of EQ to get any bass. Probably requires an active set-up and a lot of work to make it perform well on an OB. I think this is a driver intended for a boxed speaker design.

[this_is_vv]

The fs and Qts are both much lower then the Alpha 15A. So not a drop in replacement, it will need a lot of EQ to get any bass. Probably requires an active set-up and a lot of work to make it perform well on an OB. I think this is a driver intended for a boxed speaker design.

Martin,

how this replacement against eminence alpha 15A   vs Acoustic elegance IB15 

taken from following link

http://www.aespeakers.com/drivers.php?driver_id=8


IB15 8ohm
Fs: 16Hz
Qms: 6.8
Vas: 439L
Cms: .45mm/N
Mms: 220g
Rms: 3.239kg/s
Xmax: 18.5mm
Xmech: 25mm
Sd: 830sqcm
Vd: 3.07L (p-p)
Qes: .78
Re: 5.5ohm
Le: .33mH
Bl: 12.49Tm
Pe: 500W
Qts: .7
1WSPL: 86dB
2.83V: 87.3dB

IB15 4ohm
Fs: 16Hz
Qms: 6.8
Vas: 439L
Cms: .45mm/N
Mms: 220g
Rms: 3.239kg/s
Xmax: 18.5mm
Xmech: 25mm
Sd: 830sqcm
Vd: 3.07L (p-p)
Qes: .78
Re: 2.7ohm
Le: .33mH
Bl: 8.75Tm
Pe: 500W
Qts: .7
1WSPL: 86dB
2.83V: 90.35dB

[MJK]

The AE IB15 drivers should work very well in a dipole, however I do not believe AE still sells this model. But like the AE Dipole 15 drivers, which I have and currently finishing an H frame design, they need different low pass crossovers compared to a Alpha 15A if you want to get the deepest bass output they are capable of producing. I think it really means that you need to go active, passive crossovers are not going to be easy to design or work that well.

[this_is_vv]

The AE IB15 drivers should work very well in a dipole, however I do not believe AE still sells this model. But like the AE Dipole 15 drivers, which I have and currently finishing an H frame design, they need different low pass crossovers compared to a Alpha 15A if you want to get the deepest bass output they are capable of producing. I think it really means that you need to go active, passive crossovers are not going to be easy to design or work that well.

Martin,

Thank you for this, i recently got a pair form a guy so was asking. Yes i am purely active in my setup 3( Emience alpha 15a, Beta 12a and Neo3)  way active speakers with total of 6 woofers...

Only thing i am still confused is how to select the AMP power rating for each of these components....


V

[MJK]

Only thing i am still confused is how to select the AMP power rating for each of these components....

I don't know what you mean by "AMP power rating".

[majkisk]

Hello to all
My name is Miso from Republic of Macedonia and I'm new one on audiocircle
I have Lowther EX2 on Fidelio box ,amp with 2A3 and transformer volume control everything fine except bass
After some search I want to build OB speakers with Lowthers and Alpha15 or Visaton BGS40
My question here is :
If I want to use EX2 instead of Fostex (in original MJK configuration or instead DX3 as Drongo make )do I need to change something in crossover or it will be the same.

thanks and regards