AFMG Network Forum
AFMG Network Forum Index -> AFMG SysTune -> Custom File Stimulus and pre-FFT Windowing
Post new topic  Reply to topic View previous topic :: View next topic 
Custom File Stimulus and pre-FFT Windowing
PostPosted: Sat Feb 02, 2013 5:31 pm Reply with quote
Langston Holland
Member
 
Joined: 13 May 2007
Posts: 31




Hello again -

The further I get with SysTune Pro, the more impressed I am with it. In this post I have two feature requests and a bug report.

Feature Request:

1. I've mentioned this before and hopefully it's being addressed, but it's quite a pain to have to reset the trace colors, weights and anti-aliasing every time I start the program. Please have these settings saved with the "View".

2. For several years I've made two channel recordings of live measurements, then saved a phase-stable 10 second portion of same for future tuning purposes without the need to re-measure. SysTune's manual is the only one that specifically mentions this application, yet fails in one important feature to make this work. For some reason SysTune only plays back the left channel of a stereo wave file through its Custom File Signal Type. This means you have to use an external wave file player to play the separate left and right channels through the audio hardware to enable SysTune to see both channels.

This is out of character for a program that has so many stimulus I/O options. The Streaming Audio feature plays both channels of a measurement recording correctly, but ignores the audio hardware and in so doing makes it impossible to route the measurement channel through an external processor. The other measurement programs I use (Smaart v5 and v7, CLIO v10 and Audio Precision APx515), allow both channels in their "Custom File" stimulus playback. This is not a "dig" on the Streaming Audio feature - it's very nice, but insufficient.

Bug Report:

In the Options menu, there are three choices for "Use Window on Input Signal before FFT". Each function correctly when the stimulus is either generated internally by SysTune or when using the Streaming Audio feature. When using external ASIO based audio hardware, the "Always except when using internal signal generator" does not apply windowing, but works identically to "Never".

The simple work around is to only use "Always" or "Never" depending on whether the externally generated stimulus is asynchronous or synchronous, respectively.

---

Thanks for an amazing piece of software that is a gift at its price IMO.

_________________
God bless you and your precious family - Langston
View user's profile Send private message
PostPosted: Sun Feb 03, 2013 7:39 am Reply with quote
Bruce
Member
 
Joined: 19 Apr 2005
Posts: 459
Location: Minneapolis, MN, USA




Langston,

I will repeat myself on the Feature Request answer for #1. Yes, we have added it to our list of upgrades.

For #2, let me address that in a separate reply.

Regarding the Bug Report, thanks very much for your earlier email. I was about to respond when I saw this post. You are right, there is a bug, but it is slightly different than what you thought. It sometimes works correctly, that is when the ST Signal box has a Custom Signal selected. However, it is high on our priority list to fix. Your workaround is absolutely correct, as there is no ambiguity then.

And thanks also for your kind words of encouragement.

_________________
Best Regards,
Bruce C. Olson
View user's profile Send private message Send e-mail Visit poster's website
Re: Custom File Stimulus and pre-FFT Windowing
PostPosted: Sun Feb 03, 2013 8:00 am Reply with quote
Bruce
Member
 
Joined: 19 Apr 2005
Posts: 459
Location: Minneapolis, MN, USA




Langston Holland wrote:


Feature Request:

2. For several years I've made two channel recordings of live measurements, then saved a phase-stable 10 second portion of same for future tuning purposes without the need to re-measure. SysTune's manual is the only one that specifically mentions this application, yet fails in one important feature to make this work. For some reason SysTune only plays back the left channel of a stereo wave file through its Custom File Signal Type. This means you have to use an external wave file player to play the separate left and right channels through the audio hardware to enable SysTune to see both channels.

This is out of character for a program that has so many stimulus I/O options. The Streaming Audio feature plays both channels of a measurement recording correctly, but ignores the audio hardware and in so doing makes it impossible to route the measurement channel through an external processor. The other measurement programs I use (Smaart v5 and v7, CLIO v10 and Audio Precision APx515), allow both channels in their "Custom File" stimulus playback. This is not a "dig" on the Streaming Audio feature - it's very nice, but insufficient.


I need to understand better what you are trying to do. You are correct that we only play back channel #1 as a mono signal. That is because we allow you to choose which output this is then routed to for playback. That is you can choose any individual output, or send it to all outputs simultaneously. We would need a more complex matrix scheme if we played back 2 channels.

The Streaming Audio file on the other hand is intended to be used with multi-channel recordings. It is what I use to post-process a Pro-Tools recording of 8-9 channels for some of the work I'm involved with in SMPTE standards. That allows me to choose which channel is my reference channel and which is the signal on the fly, as though I had real mics open in a venue.

So, my first question is, is this a recording of a single mic and it's associated reference channel? If that is the case, then you would want to use the Streaming File input. We do have a feature request logged to allow playing this file through the audio hardware simultaneously. We'll add your voice to that existing item.

_________________
Best Regards,
Bruce C. Olson
View user's profile Send private message Send e-mail Visit poster's website
Re: Custom File Stimulus and pre-FFT Windowing
PostPosted: Sun Feb 03, 2013 7:18 pm Reply with quote
Langston Holland
Member
 
Joined: 13 May 2007
Posts: 31




Quote:
I need to understand better what you are trying to do.

Good question, sorry for the vague grammar. Hopefully the following illustration addresses your questions:



Quote:
You are correct that we only play back channel #1 as a mono signal. That is because we allow you to choose which output this is then routed to for playback. That is you can choose any individual output, or send it to all outputs simultaneously. We would need a more complex matrix scheme if we played back 2 channels.

Understood, but if it's easy to implement a 2-channel playback option (as is the default of other measurement programs), it would be nice not to have to use a 3rd party application for this. It's not a big deal to use the 3rd party app since it's required to do the recording in the first place, it just seems reasonable given the manual's strong promotion of off-line analysis on pg. 172:

"The analysis of raw measurement data or a recording at a later point of time is a very powerful function in many situations. This feature is available for Pro version users of SysTune. It allows you to load the recording of an acoustic event and process it with SysTune as if you were using a full measurement setup in real-time."

What I now understand is that the manual was ONLY referring to looping through the "Streaming Audio" feature. This is very nice for approximations in your hotel room with nothing but your laptop available, but why not take it a step further and allow the actual processor in the measurement channel loop? So close, yet so far! :)

Quote:
The Streaming Audio file on the other hand is intended to be used with multi-channel recordings. It is what I use to post-process a Pro-Tools recording of 8-9 channels for some of the work I'm involved with in SMPTE standards. That allows me to choose which channel is my reference channel and which is the signal on the fly, as though I had real mics open in a venue.

Very cool... So close!... :)

Quote:
We do have a feature request logged to allow playing this file through the audio hardware simultaneously. We'll add your voice to that existing item.

Thanks! :)

A Final Thought:

Another observation from other measurement programs is that when you playback a mono custom file stimulus it is routed to both L and R outputs. When you playback a stereo custom file stimulus, the L and R channels are sent to the L and R outputs independently.

Thus, it seems that SysTune could be modified rather easily by simply maintaining its current behavior with single channel files, but allowing multichannel file playback to address the audio interface outputs independently.

I obviously have no idea what I'm talking about when I say "modified rather easily". Concept and implementation can be like oil and water. :)

_________________
God bless you and your precious family - Langston
View user's profile Send private message
AFMG Network Forum Index -> AFMG SysTune
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
All times are GMT  
Page 1 of 1  

  
  
 Post new topic  Reply to topic  


Powered by phpBB © 2001-2003 phpBB Group
Theme created by Vjacheslav Trushkin
Variation by CodeWeavers and AFMG