Just finished my OBs with the Alpair 10.3s. Largely based on a MJK design - 16 x 16 x 16 H-frames with Eminence Alpha 15a LF drivers and a U-frame, which houses the Alpair 10.3s.
Just starting my break-in period, but already they sound AWESOME. The u-frames are 3" deep and are resiliently mounted to the h-frames with rubber grommets.
Bi-amped with a MiniDSP doing the x-over. 150 Hz LR2 for the LF and 200 Hz LR4 for the HF. No other EQ right now, just a Nelson Pass 6 dB Q-of-2 peak filter @ 20 Hz for the H-frames.
After the break-in period I'll have to sort out the dipole peak, which should be ~375 Hz or so based on simulation in the Edge.
@Markaudio -- thank you so much for this driver! Really really good stuff.
Just starting my break-in period, but already they sound AWESOME. The u-frames are 3" deep and are resiliently mounted to the h-frames with rubber grommets.
Bi-amped with a MiniDSP doing the x-over. 150 Hz LR2 for the LF and 200 Hz LR4 for the HF. No other EQ right now, just a Nelson Pass 6 dB Q-of-2 peak filter @ 20 Hz for the H-frames.
After the break-in period I'll have to sort out the dipole peak, which should be ~375 Hz or so based on simulation in the Edge.
@Markaudio -- thank you so much for this driver! Really really good stuff.
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Thanks, I had lots of inspiration for the project!
Main design is thanks to MJK:
http://www.quarter-wave.com/Project08/Jordan.pdf
Adding the U-frame to the full-range was based on the "Open-Minded" PE 2011 winner:
Openminded--An Open Back Speaker Project
As well as the sunflower OB (just the top half):
https://sites.google.com/site/undefinition/diy-sunflowers
I'm pretty happy with most of the design decisions -- If I had to do it again, I would have cut the baffle holes a bit different, I would not have used the outer plastic ring of the 10.3. This caused problems with not enough recess for my material, the need to use cleats on the back and having to use the non-supplied MA screws (my fault, but still on opportunity to improve, should I want to update the baffles.) Another option would be to make an oak outer baffle a la Brines to mount the MAs to. This is nit picky, but it is DIY and there are always opportunities to improve.
Main design is thanks to MJK:
http://www.quarter-wave.com/Project08/Jordan.pdf
Adding the U-frame to the full-range was based on the "Open-Minded" PE 2011 winner:
Openminded--An Open Back Speaker Project
As well as the sunflower OB (just the top half):
https://sites.google.com/site/undefinition/diy-sunflowers
I'm pretty happy with most of the design decisions -- If I had to do it again, I would have cut the baffle holes a bit different, I would not have used the outer plastic ring of the 10.3. This caused problems with not enough recess for my material, the need to use cleats on the back and having to use the non-supplied MA screws (my fault, but still on opportunity to improve, should I want to update the baffles.) Another option would be to make an oak outer baffle a la Brines to mount the MAs to. This is nit picky, but it is DIY and there are always opportunities to improve.
A quick update. Still breaking in the MAs so can't do real measurements yet, but I am enjoying the sound of the speakers quite a bit. I've since added a few components to my playback chain -- a pair of 300b monoblock amps and a Decware preamp. That was a big improvement right there. Right now I have the crossover of the MAs at 200 Hz LR 12 and 100 Hz LR 12 for the Alpha H-Frames.
They excel for playing Jazz LPs, or really any acoustic ensemble. The produce a nice sense of space. Instruments feel as though they are in the room with me. There is likely a dipole peak and rolloff that I could still EQ out for the full-ranges, and the H-frames can tend to sound a bit boomy at times. All-in-all I am happy with the build but may do additional tweaking to the MiniDSP settings in the coming weeks.
Here is how they look in the room:
They excel for playing Jazz LPs, or really any acoustic ensemble. The produce a nice sense of space. Instruments feel as though they are in the room with me. There is likely a dipole peak and rolloff that I could still EQ out for the full-ranges, and the H-frames can tend to sound a bit boomy at times. All-in-all I am happy with the build but may do additional tweaking to the MiniDSP settings in the coming weeks.
Here is how they look in the room:
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Just the basic miniDSP model -- The 2x4 https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4
Here is the in-room response 1/6 octave smoothed. Sounds pretty good. I'd like the take these out to measure outdoors, I'd still like to deal with the dipole peak and rolloff, as well as any other anomalies.
I did add a couple of things to the Mini DSP Crossover -- first I added some delay to the LF driver using the out-of-phase null method (i.e. flip the phase of the LF driver in the MiniDSP program and adjust the delay until you get the biggest null at the X-over point), then flip the phase back. The drivers are time-aligned. I dropped the HF response a bit using a -1.5 db 1.5kHz shelving low-pass filter. Also did a broad -4 dB peak filter at 60 Hz (as you can see I have quite a bit of bass build up in my listening room). Also added back in my 25 Hz Q 2.2 peak filter to extended the low bass a bit.
Here is the response in-room. Since, I often listen at pretty low volumes, I don't mind the extra bass response. It sounds pretty balanced to my ears. I am getting nice summing at the x-over point, which is what I want.
I did add a couple of things to the Mini DSP Crossover -- first I added some delay to the LF driver using the out-of-phase null method (i.e. flip the phase of the LF driver in the MiniDSP program and adjust the delay until you get the biggest null at the X-over point), then flip the phase back. The drivers are time-aligned. I dropped the HF response a bit using a -1.5 db 1.5kHz shelving low-pass filter. Also did a broad -4 dB peak filter at 60 Hz (as you can see I have quite a bit of bass build up in my listening room). Also added back in my 25 Hz Q 2.2 peak filter to extended the low bass a bit.
Here is the response in-room. Since, I often listen at pretty low volumes, I don't mind the extra bass response. It sounds pretty balanced to my ears. I am getting nice summing at the x-over point, which is what I want.
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