DIY PMC MB2 clone

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Thanks Charles.

The delay in samples of the filter is (N−1)/2. So when you use all the 9600 available taps this should be 4800. at 48kHz this will result in a 100ms delay
For direct recording monitoring this is unacceptable.


The latency of the minidsp should be kept below +/-5 ms. So in 96kHz mode that means a maximum of 1000 taps. I don't know what is possible with that many taps?
I could make a FIR preset and a "non FIR" when we want lower latency.
 
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You will not have to use all of the available filter taps. And when you process more than one channel at once the amount of filter taps is distributed amongst those channels anyway, shrinking the achievable delay even further. I think that you can use both, IIR and FIR, at the same time (don't know what is supported by the Mini DSP GUI). That means that you are able to use IIR EQs and do just the crossover with FIR. Using a FIR crossover with a delay around just a few ms could give quite steep slopes at an xover frequency of 600 Hz for instance.
As already mentioned the AD and DA converters do also cause some small delay due to the use of FIR filters for decimation.

Regards

Charles
 
It is not a good idea to monitor and eq a live kickdrum through esl panels. Studio monitors should be able to withstand abuse. Also the horizontal dispersion is not good enough when sitting that close to the panels.

In the meantime I aquired some oak wooden panels for the baffle. Almost ready to build.
 
Oak panels:

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The first cut. The sun came out.

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The baffle rests on felt stickers on a plate blocked by a couple of wooden strips.

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Fitting the TW29:

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fitting the Volt:

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Since they are ported cabs I'd line them with acoustic foam tiles.
No need to line the baffle but everything else and may be extra behind the woofers.
You will need to keep a clear path between woofer cones and port.

I use this stuff 908 DPM to stick the tiles to the wood.

Sheep wool is excellent for stuffing sealed cabs and last time I looked it was also the cheapest option but it is not ideal for ported cabs... not least because of the potential moth problem! :)
 
Andersonix, those cabs look nice! The woofers came in. Did some work on the baffles today.

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Testfit. Some finetuning of the depth still to be done. The woofers and tweeters have a foam backing so they will go a bit deeper.

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The mdf for the cabs is sawn and joined (not yet glued) with lamellos.

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Thanks wae. I try the best with the tools I have :)

The first cabinet is glued.

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I have to do some post routing to get a perfect flat plane for the baffle. Let's see tomorrow. The baffles are sanded and await a couple of hardwax oil layers.

The bassreflex pipes will be suspended in a support piece glued with polymax caulk. The pipes will stick out 1 or 2mm to far. The pipes will be pushed backwards as the baffle is tightened in the cabinet giving a tensioned tight fit (I hope)

The MiniDSP OpenDRC-DA8 is ordered and also some Sigma S2U nova matt black RAL 9005 paint to finish the cabinets.
 
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