32C Channel Plugin

[madmaxmiller]

If you can null 32C EQ against a stock digital EQ there is absolutely no analog magic going on whatsoever. And it's not complicated DSP that couldn't be achieved five years ago (as categorically stated in the website).

Dear Mr "bachstudies",

you obviously rely on random Youtube videos without any questioning, let alone own experiments. But your (and that Youtuber Dan's) claims of "nulling" are simply wrong.
Before you call me a "fanboi" - let me present you with my own findings.


1) Test arrangement

1.1) Used devices
To eliminate any possible influence of the Mixbus-DAW I have not used it throughout the experiment, instead I used a neutral plugin host for noise generator and 32C channel strip and used Reaper only as a ReaEQ host. So I really match the two EQs and the EQs only.

- Carla plugin host runs TAP Pink Fractal Noise as a sound source
- Carla plugin host runs Harrison AVA 32C channel strip as one of the test candidates
- Reaper v6.15 runs 1 channel with ReaEQ and direct output (not through Master)
- Ardour 6.5 serves as mixing/phase flipping device for the actual null test
- 4x Robin Gareus 1/3 Octave Spectrum Display for visual analysis

1.2) Connections
I chose the shortest possible connections to eliminate any possible influence through internal buses, master buses etc. I also didn't place the RTAs directly into the signal channels to avoid any possible influence of these plugins. I'm measuring the raw signals as they come from the signal generator and the respective EQs.

- noise out --> 32C channel in --> 32C out --> Ardour ch1 (AVA32C) in
- noise out --> Reaper ch1 with ReaEQ in --> Reaper ch1 direct out --> Ardour ch2 (ReaEQ) in
- noise out --> Ardour ch3 (SIGNAL) RTA in (RTA for original signal)
- 32C channel plugin out --> Ardour ch4 (Harri RTA) --> RTA post 32C EQ
- Reaper channel (with ReaEQ) direct out --> Ardour ch5 (ReaEQ RTA) --> RTA post ReaEQ
- Ardour channels 1 and 2 --> Ardour MASTER for summing, all other (RTA) channels have no master connection
- Ardour Master has an RTA for the sum signal

Screenshot 1: test arrangement
   

1.3) Checking the test arrangement
- bypass all plugins
- run noise source
- check meters

We see: noise comes in and out at -6.3dB evenly on all channels except the master channel which logically shows -3.3dB as a summing result. All RTAs show identical pictures. Flipping one phase results in a perfect null as it should be with everything EQ bypassed.

Screenshot 2: signals
   

Screenshot 3: NULL at bypass
   

We are ready to go!


2) The test

2.1) both EQs switched on but all dials on neutral. In the AVA32C plugin ONLY the EQ is used, all other stages like HP/LP and compressors stay bypassed - the result should be null.
- meters appear unimpressed
- phase flip nulls perfectly - as expected
in neutral positions nothing should happen

2.2) second check of the test arrangement: If I change 1 EQ while in phase flip there should be a difference
- checked alternating with both (only one engaged at a time) and it works

Screenshot 4: only 1 EQ altered
   


2.3) trying to dial in equivalent settings
- lower mid 1kHz +3db --doesn't null, lowest result was when moving the bandwidth slider to 2.72 oct at the ReaEQ
- higher mid 3kHz -3db - lowest result at 2.82 oct bandwidth in ReaEQ but never null
- both above combined and Q-tweaked - never nulled
- changing channel levels in ardour always resulted in higher differences, as expected, look at the meters!

Screenshot 5-7: both EQs set to same values and ReaEQ's Q set to lowest difference
   
(sorry the other two screenshots are in the next post because of forum restrictions)

3) Conclusion: I have diligently built my test equipment and method to eliminate all possible flaws. Please correct me if you find error.
The tests showed that even with very moderate settings it is not possible to achieve a NULL between the 32C channel EQ and ReaEQ, as claimed by other parties. The EQs differ in frequency characteristics and I expect them to differ even more with more advanced settings. In all tested cases the differences were not only visible in the RTAs but also very well audible, around -57 dB. This was tested with pink noise, a real musical signal will show more difference in character.
Therefore I suggest that either the test arrangements or the methods or both in the mentioned Youtube videos were flawed if not manipulated.

All used tools or similar are freely available and everyone is invited to try themselves.

Happy Mixbusing!

MMM