Pro Tools for Media

In part 1 I explained the challenge and a potential solution. In this part lets see if the solution delivers…

Once fully installed, I inserted an instance of Repli-Q in the session to see how well it would work in this situation.

This is how I had laid out the session. I put the reference take on one track and then the muffled take on another track. This is so I could adjust the EQ on the muffled track but still hear the reference file untreated. When making comparisons like this, don’t listen to short snatches of the reference, followed by the region you are treating, as you can easily get fooled into thinking things are better when they are not. I always listen to the full reference region and then a good chunk of the region to be treated to make sure I was going in the right direction, yes it took longer but was well worth it in the end.

So with Repli-Q in the session, I bypassed the EQ plug-in on the ‘muffled’ track and moved the reference region down onto the muffled track so I could switch from one to the other with Bias’s plug-in.

Learn once

Next I opened up the Repli-Q plug-in, selected the reference region, hit Play and then Learn Spectrum in the Repli-Q window, and let it play for as long as possible through the reference region.

Bias recommend that you should always start playing before you hit the Learn button so that Repli-Q doesn’t try to learn digital silence and the same at the end, so I clicked the Learn Spectrum again before hitting the Stop button in Pro Tools. Now I had a green trace on the graph that represented the ‘reference’ files signature.

When I saved the profile by hitting the Save Spectrum button the trace turned to yellow.

Learn Twice

Now I highlighted the muffled region, hit Play again, hit Learn Spectrum and let Repli-Q learn the signature for the region I needed to treat. Whilst it was learning I got a green trace together with the yellow trace presenting the reference file.

Again hitting the Learn button stopped the learning process, and I remembered to leave it run a long time to get a good average for the ‘muffled’ region’s profile. Having clicked the Learn Spectrum again the plug-in displayed then three traces. The yellow trace represented the profile for the reference region, and then two traces for the ‘muffled region, a green trace for the input profile and a blue trace for the output profile. Now I could adjust the amount of EQ added to the muffled region with the Matching slider. I found that as I slid the Matching slider from its default 50% down to 0%, the plug-in had no effect on the treated audio, through to 100% where the output profile was identical to the input profile and so the maximum EQ change was applied to the muffled region.

Graph to EQ

I found it much easier at this point to see this in action by changing the display from Graph to EQ.

I could then see the EQ that Repli-Q was applying to the muffled region to get it to match the reference region.

Does it work I hear you ask? Well yes it does, it produced a much more natural treated region than I had achieved with an EQ plug-in alone. But having listened to the treated version carefully I noticed that there was an increase in low frequency background noise and it was still not quite bright enough for my taste. However with Repli-Q’s EQ curve pointing me in the right direction, and with the help of an EQ plug-in, in my case an instance of Waves Renaissance EQ 4, I applied a low frequency shelving to compensate for the increase in low frequencies shown above and also a fairly tight parametric boost centred around 7k to add to what Repli-Q was already doing.

With the two together I had a very close match and all done in about 10 minutes. All I needed to do was to render the treated files so they were the same length as the originals to make it as easy as possible for the video editor to replace the muffled regions with the treated ones. To do this, I copied the settings across from the real time plug-in to the corresponding AudioSuite version so I could process the files and then disable the real time plug-in to save computer processing power. Finally I send the processed file back to the client using the Sharing function on my Mobile Me iDisk.

Conclusion

The Repli-Q did a much better job, than I did, especially once I had helped Repli-Q along the way with a bit of extra targeted EQ and at around $149 for the single plug-in was well worth the money. Yes I could have persevered with EQ and matched it better but to have a simple to use tool that produced a very good result quickly is well worth it, after all time is money!

The problem

A client had recorded a video voiceover but for some unexplainable reason several of the takes were ‘muffled’. They sent an example and a reference file over via ftp and I had a listen and sure enough it was muffled but it didn’t sound like just an EQ problem but I couldn’t quite put my finger on it, I thought that the muffled takes may have been recorded as an mp3 but apparently not, it was one complete session. I was able to match them with EQ reasonably but I thought it would be worth doing a search on the Digidesign User Conference and found a very interesting current thread. It was all about this very subject. Don’t you just love when that happens?

The Solution

The first suggestion was to use Dynamic Spectrum Manager from Pro Audio DSP with the advice to use sparingly and then a number of posts outlining how hard it was to get DSM to function as an EQ Matching application as it is described by Pro Audio DSP as a “groundbreaking adaptive techniques to capture both the frequency-domain and dynamic characteristics of audio program, and uses this as the basis for a highly developed large scale multi-band compression process.”

To this end the advice is it can do great things but needs careful use and as so often in my workflow, time is tight, so I moved onto the next suggestion.

Bias Repli-Q from their Master Perfection Suite.

As it happened, I already had Master Perfection Suite on my computer, which was even better news! However if you aren’t as fortunate, you can download a free 14 day trail from Bias, all be it the complete Master Perfection Suite which also includes 5 other applications and comes in VST, AU and RTAS plug-ins.

In part 2 I will show you how I used it and whether it delivered the goods or not.