• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

[As designed] Exported IR from TMA out-of-phase (and 9 dB level difference)

yyz67

Inspired
I have been trying to use a combination of TMA and IRs saved from TMAs and occasionally get what seemed to be large cancellation, sometimes between the TMA and an IR from a TMA or between two IRs from different TMAs. I have confirmed on FW 8.00 that if I export an IR from a TMA and then put them in parallel, there is a clear cancellation (large drop in volume, though not perfect cancellation).

As has been noted by others, exported IRs are quieter than the TMA itself, and it appears that increasing the level of the saved IR by 9 dB (whether in an IR Player or CAB) brings them to the same level. I don't know if this is a bug or by design. Using the same 9 dB boosted IR (via IRP or CAB block) in parallel largely cancels the TMA.

Attached preset and IR used (FW 8.00):
Scene 1 - Original tone match​
Scene 2 - IRP using the saved IR from the TM (+9 dB)​
Scene 3 - CAB using the saved IR from the TM (+9 dB)​
Scene 4 - TMA and IRP in parallel demonstrating cancellation​
Scene 5 - TMA and CAB in parallel demonstrating cancellation​


Here's a recording stepping through the 5 scenes:

 

Attachments

FractalAudio

Administrator
Fractal Audio Systems
Moderator
The Cab and IR Player blocks automatically "phase correct" IRs so that the peak signal is positive. A Tone Match may have the peak signal negative. When putting them in parallel this will lead to cancellation.
 

yyz67

Inspired
@FractalAudio thanks, I think that makes sense. I have also had an out-of-phase issue with two IRs saved from different TMs, thus being able to use multiple TMs (as TMAs and/or as IRs) seems to be a bit luck of the draw?

Would it be possible (and would you be willing) to implement a "phase correct" (or "phase invert") on/off switch either in the TMA or IR/CAB or both?
 
Top Bottom