Use acoustic timing reference

[Leo Risbridger]

Hi,

I have a question regarding playing sweep files with Roon and its Roon DSP Convolution Filter Engine. Essentially I want to take a REW Sweep measurement that includes the correction of the Roon DSP Convolution Filter.

My environment is:
- Mac mini with Roon Core - USB Interconnect - Pro-Ject Pre Box S2 Digital - March Audio P252 - Harbeth P3ESR
- mac OS Mojave 10.14.4
- REW macOS DMG (includes private Java 8 JRE) V5.20 beta 7
- Roon Core Version 1.6 (build 401) stable (64bit)
- Convolution Filter created by Home Audio Fidelity (HAF)

I have successfully exported Noise and Sweep to Wav Files including adding the timing reference to the external Wav files. I have then imported these files to my Roon Library. Roon has volume auto levelling enabled. See attached Screen Shot

I initiate a REW measurement with "Use acoustic timing reference - Timing Offset = 0.000ms - Ref level trim = 0.0dB "

My expectation is that the measurement will initiate to 11% and then wait to hear the "Timing Reference" - My intent is to then play the exported Timing Ref + Sweep file via Roon with the corrections applied by the Roon DSP Convolution Filter Engine.

Reading some old "Roon Community Forums" they mention muting my computer - This is macOS, my default output is set to Pro-Ject Pre Box S2 Digital; If I mute with Sound Preference then Roon output is also muted but REW is waiting for the timing reference (see attached Screen Shot).

However, when starting the measurement with macOS Sound Preferences "un-muted"; REW does NOT wait for the timing reference - REW immediately plays the "Timing Reference and the Sweep".

Thanks in advance for your responses.

 

[John Mulcahy]

On the right side of the Measure dialog next to "Playback" click the "From file" button.

 

[Leo Risbridger]

Hi,

I selected "From" file; Browse to an external "Timing Reference Signal + Sweep" Wav file; Choose which channel (Left or Right) to import.

REW waited for the "Timing Reference Signal". I initiated "Timing Reference Signal + Sweep" within Roon.

I am very new to REW; Given that I am trying to initiate a sweep measurement externally to REW, it was non-intuitive to browse to an external "Timing Reference Signal + Sweep" Wav file within REW.

From searching various internet forums, my understanding is previous REW versions had a simpler user interface with a checkbox for "Wait for Timing Reference Signal".

Many thanks for the assistance.

 

[John Mulcahy]

To get a valid result REW needs to be set up with identical sweep parameters and sample rate to those used to generate the file. That data is embedded in the file, loading it into REW is the most reliable way to ensure the setup matches the file used.

 

[Leo Risbridger]

Hi,

Given your comments, the user interface makes sense now.

I have attached some screen captures for reference.

Many thanks for your assistance.

 

[Kirk Boone]

Off the subject, but I noticed in a search that you use the March Audio P252 amp. Can you offer your impressions of this amp? I've been thinking of getting an Ncore product. Thanks.