With the miniDSP 2x4, the 2-way [inc. Advanced] & 2.1 plugin don't give channel routing, they're always stereo. To go 1x4 you need to buy the Matrix plug-in [$10], this adds channel routing and you'll be able to split a mono input to all 4 outputs 
MiniDSP do the miniAmps which stack atop the DSP unit, these are $60 each and will do 2x20W, 4x10W or 2x10 & 1x20W for 2.1... Neater integration, but more expensive than the TPA3116 based boards.
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21 days and counting, still no sign of the Vifa TC9FD or MA A7.3 drivers I've ordered. The MA units were in stock and the Vifa units were supposedly in stock with Strassacker's suppliers, with delivery expected within 14 days.
Started the process of chasing the order and waiting upon a reply from an e-mail sent Friday morning... Might end up buying the Faital Pro units yet.
MiniDSP do the miniAmps which stack atop the DSP unit, these are $60 each and will do 2x20W, 4x10W or 2x10 & 1x20W for 2.1... Neater integration, but more expensive than the TPA3116 based boards.
|-O-|
21 days and counting, still no sign of the Vifa TC9FD or MA A7.3 drivers I've ordered. The MA units were in stock and the Vifa units were supposedly in stock with Strassacker's suppliers, with delivery expected within 14 days.
Started the process of chasing the order and waiting upon a reply from an e-mail sent Friday morning... Might end up buying the Faital Pro units yet.
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Can you use the Matrix plugin in combination with the XO function of the 2x4 Advanced XO? It doesn't look like you can use two plugins at once. They just need to make a mono 1x4 button for the 2x4 and it would do exactly what I need.
Edit: I think what I want is the Advanced 4 way XO plugin per minDSP 2x4 board. Each board goes to 2 power amps for 4 channels of active XO and EQ.
https://www.minidsp.com/products/plugins/minidsp-2x4-kit-box-platforms/4way-advanced-detail
https://www.minidsp.com/images/documents/Product%20Brief-4way%20Xover%20ADV%20plug-in.pdf
Edit: I think what I want is the Advanced 4 way XO plugin per minDSP 2x4 board. Each board goes to 2 power amps for 4 channels of active XO and EQ.
https://www.minidsp.com/products/plugins/minidsp-2x4-kit-box-platforms/4way-advanced-detail
https://www.minidsp.com/images/documents/Product%20Brief-4way%20Xover%20ADV%20plug-in.pdf
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Yes, does look like the Mixer plug-in is separate... the miniDSP user manual made it look like an add-on pack. The mixer looks be similar to the standard 2-way plug-in, so no PEQ, just a standard graphics equaliser.
Not sure the advanced 4-way would be useful, as it also looks like it doesn't allow channel routing. Think you'd still be stuck with 2x4, despite the 2x8 plug-in
Not sure the advanced 4-way would be useful, as it also looks like it doesn't allow channel routing. Think you'd still be stuck with 2x4, despite the 2x8 plug-in
I have used 4way advanced with my 2x4 and I was wondering about the comments about additional plugins.. I did not try which channel (I use miniDSP to evaluate XO points etc on one speaker, not for a pair) it uses for input, but it definitely outputs to all four, otherwise it would not be 4way
Thinking about it, you are correct that the 4-way plug-in would [and does] work with the miniDSP 2x4 to give 1x4 ...
Default channel routing on the 4-way plug-in's looks to be set as I2S In 1 > I2S Out 1&2 and 3&4. I2S In 2 > I2S Out 5&6 and 7&8... So using the 4-way plug-in with the 2x4 would direct a single input to all 4 outputs, as the outputs are I2S Out 1&2 and 3&4 ... Happy days
I forgot this as I changed the routing on the miniSharc.
Default channel routing on the 4-way plug-in's looks to be set as I2S In 1 > I2S Out 1&2 and 3&4. I2S In 2 > I2S Out 5&6 and 7&8... So using the 4-way plug-in with the 2x4 would direct a single input to all 4 outputs, as the outputs are I2S Out 1&2 and 3&4 ... Happy days
I forgot this as I changed the routing on the miniSharc.
I ordered a couple of the green board YBDJ TPA3116D2 amps from Aliexpress 8 weeks ago - the tracking info says it should finally be arriving tomorrow. Never buy from them again - way too slow... Anyhow, I will have two boards to try out this 4-way XO idea, or a 2-way bi-amp with compact boards all mounted in one box with the miniDSP.
I really like the idea of the slot loaded OB also, but for a first try a simple single layer baffle will be the quickest thing to do. Baffle will be 20" x 38", the Eminence centre should be 10" up from the bottom, the Vifa centred at 32" and offset 2" from the centre line.
For fun, penned two different OB designs in ShetchUp. Simple OB is twin layered, with CLD between MDF rear and wood front. Slot loaded OB is for 4 x 8" woofers and duel Vifa/Faital Pro drivers.
For fun, penned two different OB designs in ShetchUp. Simple OB is twin layered, with CLD between MDF rear and wood front. Slot loaded OB is for 4 x 8" woofers and duel Vifa/Faital Pro drivers.
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You will be in DSP bi-amp OB heaven with all those drivers to play with . Your quad 8 in driver slot loaded setup with tweeter cutouts look great. Did you know Z posted his SW files on his thread so anyone can send them to a CNC mill and get identical speakers made without generating sawdust at home? I am really curious about the Faital Pro - they appear to be like the Vifa but with 91 dB to boot. Keep us posted - I am also curious if you find out if you can hear a difference when using regular IIR EQ and XO (as I have in my 2x4 miniDSP) vs the FIR version that you can get in your miniSHARC?
Happy OB trails!
. Your quad 8 in driver slot loaded setup with tweeter cutouts look great. Did you know Z posted his SW files on his thread so anyone can send them to a CNC mill and get identical speakers made without generating sawdust at home? I am really curious about the Faital Pro - they appear to be like the Vifa but with 91 dB to boot. Keep us posted - I am also curious if you find out if you can hear a difference when using regular IIR EQ and XO (as I have in my 2x4 miniDSP) vs the FIR version that you can get in your miniSHARC? Happy OB trails!
The M J King OB design real called for 90dB FR units, so purchased the 4FE35's, but will also try the Vifa units.Not tried the FIR filters yet, would need to manually enter the REW generated bi-quads into a FIR program to get the filters... something to play with over the coming weeks & months
Seen Z's post, question is, how universal are the woofer mountings & plenum size... iirc, the units he used aren't available any longer.Basic OB in yellow & red [with bulbous edges]... have the idea of getting some big posters and gluing them to the baffle fronts... bringing some art & colour into the room
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I tried the spiral shaped Nautilus baffle around the FR unit as suggested by another thread - it does seem to work to smooth the diffraction caused by the rectangular edges on the top and sides without losing too much bass extension so that it can be integrated nicely with the woofer around 300 to 350 Hz.
The FIR manual entry makes trying it on the fly not a possibility. You basically have to settle on your EQ and XO settings with conventional method first.
Re Z's design, I have SW so I can mod it to accept the 6.5 inch woofer I plan on using. The slot chamber and port dimensions are not too critical based on what I have seen from my sims and measurements. Nothing a little DSP can't fix
The FIR manual entry makes trying it on the fly not a possibility. You basically have to settle on your EQ and XO settings with conventional method first.
Re Z's design, I have SW so I can mod it to accept the 6.5 inch woofer I plan on using. The slot chamber and port dimensions are not too critical based on what I have seen from my sims and measurements. Nothing a little DSP can't fix
If the 4FE35's data is correct this is a fantastic full-range. That said, many times mfgrs. curves are overly smoothed. Does anyone have measurements on these?
Anyway, this simple/honest build will sound fantastic, but you can improve the design with cutouts using just a jigsaw and this would give you much better directivity vs frequency; center the FR. Something like this:
Cutouts not to scale
This would not be possible without eq. but with the mini Sharc setup you'll have plenty of capability to work this out. (Damn, I want to go downstairs and cut some holes in MDF scraps I have- LOL.)
Careful about listening to me though, next I'll be talking you into the CLD layer and steel U-channel bracing with compliant damping mounts
.Let me know if you have links to independent measurements for the 4FE35.
Thanks, Z
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Z,
Neat idea. So you are saying that a simple 1.5 in wide U shaped cutout around the lower portion of the full range but leave the rest of the baffle wide? Does the extended baffle beyond the U help to lower the full range driver's OB low freq cutoff so that it can integrate with the woofer at a lower freq like 300 Hz or so? This is certainly easy enough for me to take an xacto to my cardboard slot loaded OB to see how it works. With the U cutout, is there still any point in off setting the full range driver so that no two edges have the same distance to avoid diffraction?
Regarding. The 4FE35, it is relatively new here in the states so I have not seen anyone post measurements yet. I started a thread http://www.avforums.co.za/index.php/topic,31565.90.htmlasking if anyone has used these Faital Pro drivers. There is a link to this guy in Sweden ("Stupid old man with a few good ideas" - Ingvar Ahlberg) who builds pretty cool speakers with them. Based on his comments I think these drivers are the real deal. We will have to see what the measurements look like when someone gets them though.
Neat idea. So you are saying that a simple 1.5 in wide U shaped cutout around the lower portion of the full range but leave the rest of the baffle wide? Does the extended baffle beyond the U help to lower the full range driver's OB low freq cutoff so that it can integrate with the woofer at a lower freq like 300 Hz or so? This is certainly easy enough for me to take an xacto to my cardboard slot loaded OB to see how it works. With the U cutout, is there still any point in off setting the full range driver so that no two edges have the same distance to avoid diffraction?
Regarding. The 4FE35, it is relatively new here in the states so I have not seen anyone post measurements yet. I started a thread http://www.avforums.co.za/index.php/topic,31565.90.htmlasking if anyone has used these Faital Pro drivers. There is a link to this guy in Sweden ("Stupid old man with a few good ideas" - Ingvar Ahlberg) who builds pretty cool speakers with them. Based on his comments I think these drivers are the real deal. We will have to see what the measurements look like when someone gets them though.
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The idea is more that the narrow baffle around the small driver (about 2x the diameter wide, total) will keep it working like a dipole up until the driver starts to beam. Otherwise you'll get dipole bass with wide "bloom" at some point after you cross to the FR, probably between 800-2k (guess) because the baffles too wide. The extended baffle beyond the u does help a little but that's not the main point, the cutout will cause you to loose more low end from the FR but you just eq it flat. That's why most of the dipoles are 4-way, the eq can only work so far before you run out of power. I would be a little nervous doing cutouts in cardboard, might be too floppy. Could you glue a vertical rib that connects above and below the FR and crosses the gap? Love that you can try this so quick!
Anyway, you'll fully have the addiction once you start to measure the directivity every 5 degrees; Arta makes great plots. I'll see if I can get you a picture of my home brew turntable in a few days.
My question is: Why is this thread in "Fullrange"? Multiple drivers, DSP crossovers, electronic eq., listening off-axis for goodness sake!!!
Heresy.Z