PAP Trio 15 and DIY - Discussion

Did you selected "Add Response to Crossover" on "Baffle Designer"?

The T/S parameters have to be entered into PSD-Lite from the specs. The midrange box cannot be removed. Just make it small, 0.1" thin, and also select "open baffle" for it to make it inconsequential.

Feel free to attach some screen captures and we'll see what we can do.

 

It kind of halves the impedance, but the crossover is also in play. But the driver they are using is "8 ohms" for that reason. Don't rely to much on independent circuits that do not consider both the sensitivity and impedance of the drivers. You need to model the whole thing.

Also, forget about flat impedance. Concern yourself that it is above about 4 ohms everywhere to avoid taxing the amplifier.

 

I'll do the RAL design model with a new xcover for @crazychile. The one I did before for that one did not include the open baffle consideration.

 

@crazychile here is what I get for the ESS (as a starting point):

Assumed box:



Assuming open baffle design with 54 cm width, 116 cm height and 27 cm depth. 15" woofers on top and bottom of the baffle.

For this, here are the xovers:

Low woofer:



2nd order LC filter with cut-off at 187 Hz.

High woofer:



2nd order filter (or 1st order + Zobel), with cut-off at around 438 Hz.

Full range ESS:



1st order capacitor rolling things out to effectively yield a 1 kHz cross-over frequency after the woofer is tamed. The inductor tames the ESS treble climb. No need to install the 10 kohm there, that's just because I couldn't put the 0.05 mH inductor on it's own in the model.

@crazychile, let me know if this is more or less what you get.

NOTE that the full range woofer is connected in NEGATIVE polarity with the 15" woofers.

As far as impedance, all is around 4 ohms and above:



I'm assuming about 0.2 ohms of coil resistance for inductors.

 

Did you try the settings above to see if you get the same results?

 

Maybe check the "drawing scale" lever. Baffle dimensions can make not so subtle difference. Make sure you get the same dimensions of the PAP Trio 15.

EDIT: Also sometimes the effects of open baffle don't happen on the other drivers until you click on them after you selected open baffle for woofer. Make sure all have that ringy behavior from back reflection.

 

That one is awesome. Thanks for bringing that DSP processor on!

The deal is that one processor is 4x8. So maybe one could do stereo 2x6 into the drivers and then even have 2 channels left of possible sub-woofer.

On top of that this is a high sensitivity design. So even if one dedicates 3 amps for a speaker (one for each driver), one does not need a monster amp for each.

 

For amplifier I guess one could use this:

https://www.parts-express.com/dayton-audio-ma1240a-multi-zone-12-channel-amplifier--300-815

Set it to Line in for each channel and life is good.

 

It's more than up to the task for this application. SNR specs look good, and internal bit-widths look good as well. Not sure what makes you think otherwise.

EDIT: In fact, there is goodness in this approach because bass management due to room interactions can be a bitch. And it's probably going to be a bigger issue with an open baffle. A DSP might be needed anyway, so might as well go for it all the way.

EDIT 2: One can do either way. Do an analog crossover, or a digital. I don't see how the digital equalization/crossover approach suggested by @Donald North "may not be up to the task for this application". IMO, it's more up to the task. And the price for the unit is awesome for what it can do, and what's inside.

 

I understand your concern. However, I don't think it is well justified. Make sure you match the dynamic range of the stereo DAC to the dynamic range of the equalizer ADC to utilize full bit-width. Then it is more likely that your amplifier and even more so, your drivers, will dominate SQ.

This is not a SonarWorks or a DMG Equilibrium. This is a dedicated DSP and it will not be bugged down by other tasks.

Based on the little I know, I believe this approach is pretty solid. However, if you feel you can tell the difference between one piece of SW vs another on a PC, and this makes you on easy, then don't use it.

But don't shot it down w/o trying it first.

 

@GoodEnoughGear, many experienced folks here, that actually know WTF they are doing, equalize their setups with modified Berhinger equipment (w ADC/DAC on them) and similar.

I do my little active Mackies + Dayton 12" sub one in my bedroom with an even lesser DSP. And so far so good.