My $100 prize ended with another $100 on order. Including an ICEpower 300AS1 for a future bad idea. 
I looked over the Hypex stuff. But it seemed like the factory measurements Hypex does are for much higher distortion levels. So I figured the ICEpower stuff is probably just as powerful (if not moreso) for the price if you compare distortion levels.
The FA123 is rated 100W into 4 ohms and 75W into 8 ohms for the tweeter channel output. The other two channels are rated 125W each into 4 ohms or 75W each into 8 ohms. I’m currently working on a three way test loudspeaker using a 4 ohm tweeter, 4 ohm midrange, and 4 ohm woofer section, so this should work out fairly good in terms of power output. If I like the sound quality of the Hypex amps, I might consider picking up a pair of FA251’s to drive a pair of subs (130W 8 ohms and 250W 4 ohms). This will give me the ability to develop a completely digital 4 way system with time aligned drivers.
Based on @rstillin 's analysis, I was curious as to whether or not the additional vents that I added to my FA123 fusion amp mounting were really necessary (see above posts). So I spent some time temporarily converting my plate amp mounting system back to the User Guide specs so that I could conduct an A/B comparsion.
The internal plate amp chamber that I built is a bit larger than the user manual recommended dimensions. I made it 360mm high by 133mm wide by 60mm deep. The user manual internal dimensions are 336mm high by 96mm wide by 55mm deep. I used the extra height of 360mm to create room for an extra lower slot vent. I used the extra width of 133mm to create room for 8 extra slot vents along the sides of the plate amp (see pics below). I boosted the depth from 55mm to 60mm, because this was suggested on another forum and it seemed like a good idea to me.
So for the test, I needed to temporaity convert this back to the user manual dimensions and then seal it off. Only the ten small vent slots on the upper and lower portion of the plate amp itself would remain open. And the internal dimensions of 133mm and 360mm would be reduced back down to 96mm and 336mm with wooden blocks and rails. I left the 60mm depth dimension alone, however.
Here are a few pics showing the conversion process:
Width reducer rails (two) and slot plugs (8):
Below: Width reducer rails installed. Foam used to press-fit & fill.
Below: Eight plugs installed:
More to come. I’m still working on the spreadsheet showing the final test results.
That’s a lot of effort (needed) for your venting test. Outcome should be interesting.
Thanks. I figure that if I learn something, then it is well worth the time and effort.
Here are the test results for my plate amp setup with 8 extra vent slots and the wider 133mm internal enclosure. I measured the temperature over a 2 hour period with the amp consuming a constant 18W of power, but not playing music. I used one DMM to measure the temperature inside the chamber and another DMM to measure the temperature on the surface of the plate amp’s mounting plate/heatsink. The FA123’s output devices and power supply dump most of their heat directly into the aluminum mounting plate, which then dissipates this heat into the enclosure and outside air. This is why the internal enclosure temperature is always a little bit lower than the aluminum mounting plate. (Except when you shut the power off. Then the plate surface temperature drops below the internal enclosure temperature after about 10 minutes or so.) I stopped testing and shut the power off after 2 hours because the temperatures seemed to be remaining fairly stable at this point.
| Elapsed Time | Internal Temp | Plate Surface Temp | Idle Power | Room Temp |
|---|---|---|---|---|
| 0 MIN | 78F | 78F | 18W | 78F |
| 10 MIN | 82F | 86.1F | 18W | 78F |
| 20 MIN | 84F | 94.3 | 17W | 79F |
| 30 MIN | 87F | 97.8F | 17W | 79F |
| 40 MIN | 88F | 99.7F | 17W | 79F |
| 50 MIN | 89F | 101.1F | 17W | 79F |
| 1 HOUR | 89F | 101.7F | 17W | 79F |
| 70 MIN | 89F | 101.5F | 17W | 79F |
| 80 MIN | 91F | 102.5F | 17W | 79F |
| 90 MIN | 91F | 102.7F | 17W | 79F |
| 100 MIN | 91F | 103.1F | 17W | 79F |
| 110 MIN | 91F | 102.8F | 16.5W | 79F |
| 2 HOURS | 91F | 103.0F | 16.5W | 79F |
Here is a photo of the actual test, probably taken somewhere around the 1 hour mark:
Still working on the test result table for the setup with the extra vent slots plugged, using only the smaller slots for venting. Will try to post this later today, together with some concluding remarks.
Here is the table for the 2 hour test on the version with the extra vent holes filled and plugged, using only the small vent slots at the top and bottom of the aluminum plate to dissipate any heat build up.
| Elapsed Time | Internal Temp | Plate Surface Temp | Idle Power | Room Temp |
|---|---|---|---|---|
| 0 MIN | 76F | 76F | 18W | 76F |
| 10 MIN | 82F | 85.8F | 18W | 76F |
| 20 MIN | 87F | 93F | 17W | 77F |
| 30 MIN | 93F | 97.1F | 17W | 77F |
| 40 MIN | 96F | 100.1F | 17W | 77F |
| 50 MIN | 98F | 100.1F | 17W | 77F |
| 1 HOUR | 100F | 103.4F | 17W | 78F |
| 70 MIN | 102F | 104.3F | 17W | 78F |
| 80 MIN | 102F | 105.1F | 17W | 78F |
| 90 MIN | 104F | 105.7F | 17W | 78F |
| 100 MIN | 104F | 106.1F | 17W | 78F |
| 110 MIN | 105F | 106.5F | 16.5W | 78F |
| 2 HOURS | 105F | 106.7F | 16.5W | 78F |
Here is a photo of the setup, probably taken somewhere around the 100 minute mark of the testing cycle:
Conclusions:
Wait! Why do you have a Pindyck and Rubinfeld Econometrics book? Do you have an economics background?
Yes, I have a worthless BA in Economics from the University of Wisconsin (the dismal science). I’m finally getting some good use out of that old textbook. Props up the power meter just right for taking photos! 
Very cool, UW has a strong Econ program!
I guess that’s what happens when you mix electronics with economics! 
That’s why you used custom vent plugs instead of masking tape for this experiment, too!
Invaluable: Econ 101
Nailed it on your 1sttry.
Progress report:
So far, I have the standard IIR filter implementation procedure figured out and can set up a standard set of non-linear phase filters in VituixCAD (VCAD). I have also figured out how to manually transfer these filter blocks to Hypex HFD’s “Filter Component Design” screen. Kind of a clunky process, but it works. Been listening to a couple of very simple two way crossover topologies with cheap drivers. The FA123 has three built-in presets, so I can quickly switch back and forth between xover variants and listen for differences.
To set this up with the Hypex plate amps, you first must develop a crossover in VCAD using several analog active IIR filter blocks. Then you print out VCAD’s schematic CAD screen, which shows all the filter block values listed directly below each block. Equivalent filter blocks are then created in HFD by manually re-typing the values for each IIR filter block on the printout. This is a very slow, time consuming process that must be done for each filter block for each driver! Up to a total of 15 biquads for each driver in each Hypex software processing “channel”. When done, you can then upload each driver’s filter “channel” to one of the three plate amplifier’s on-board DSP memory slots (or presets). Works pretty slick. (Note: I’m putting quotes around the word “channel” because Hypex is using this term to describe monophonic driver channels. Not to be confused with right or left channels is a stereo system setup).
FIR filtering, however, is accomplished by generating a FIR phase correction impulse file in VituixCAD (or rePhase) and then uploading this file to the Hypex HFD software package. The FIR file is a text file that has either 4500 or 1500 lines (or taps) of biquad coefficient values. You cannot simply re-type this data into the Hypex HFD program, as was done with the simple IIR filter data. You must export and upload the data into the program the same way you would load an FRD or ZMA file into XSim or VCAD. The problem is, however, that the file format has to be the exact format (or layout) that is required by the HFD software. If not, you get an error message (see below). I spent several hours getting error messages before re-reading page 17 of the HFD user manual and discovering my mistake.
Below: Error message received during my attempt to load FIR file:
So this is what you have to do to avoid the input error:
I have yet to actually implement FIR filters on one of my test crossovers. It took me quite a while just to figure out how to create and import them. I’m still undecided on whether it is better to create a global FIR filter with 4500 taps. Or to create 3 separate small FIR filters with 1500 taps each. Most of what I have read on other forums seems to indicate that 1500 taps is the way to go. Not sure what the pros and cons are.
Test example of the correct FIR filter export settings:
Test example of FIR filter file that can be imported to HFD with NO error message (showing only the first 29 lines of the 1500 line file):
Test example of FIR filter file that creates the error message. The b0 to b1499 text and equal sign, plus the extra comma delimiter at the end of each line create an error message. This file was created using the "miniDSP manual mode (*.txt) export option:
Don’t think I would have the patience for that.
Exactly WHY I sent JR a message just now . . . .
Speaking of, haven’t seen him around in a bit.
Yeah, me neither.
