Help with DRC, please?

[VOBOSHI]

Hello all,

 

I'm glad I found this community. I've been an avid reader for over a year but now reaching the end of my wits and can't deal with this situation all on my own.

 

I own the following:

- 2x Genelec 8320 speakers, 1x Genelec 7350 subwoofer, GLM kit

- MOTU M2 audio interface

- Earthworks M23R mic, mic stand

- cheap SPL meter

- @mitchco's Accurate Sound Reproduction Using DSP

 

I have the speakers set up in a fournished room, fully carpeted, with a black-out blind on the one window. As much as possible, the speakers were positioned / aligned in a equilateral triangle. Subwoofer sits about centrally, at a very slight distance from the wall. The wall that the speakers face away from has a protrusion, meaning the speakers are in alcoves, and the left speaker sits next to the room's door.

 

I won't be here in a year's time which is why I haven't contracted a company for room treatment, but I'm trying my best to squeeze every last drop out of the gear in this room, which is why I figured I would try DRC.

 

What I've done so far:

- I've used Genelec's GLMv3 for AutoCal & AutoPhase

- I've followed @mitchco's book with a trial version of Acourate, but since I couldn't export anything / see a meaningful result without paying, I stopped that effort; before shelling that amount of money I'd prefer to see some value from DRC for free

- I've followed this guide from the Roon Community forums (I subscribe to Roon) on using REW and have done measurements for each speaker, exported the filters for each sample rate (44.1kHz all the way to 192kHz) and tried them in Roon; they make a difference (as in, I can hear music differently), but the way I'd describe that difference is subdued. It sounds like the highs, especially, are different.

- I've also tried following this guide from @mitchco on using Audiolense instead, which does offer a way of sampling its results for free, but couldn't even start measuring the room with it, as it's complaining the two outputs are more than what my audio interface has available. That's a problem for a different day, though, and as per their documentation, it's most likely something with either my interface or just my general lack of knowledge.

 

I guess my question would mainly be... How can I validate that the filter generated with REW does what it's supposed to do? I'm thinking I could use its RTA feature on the same snippet of a song, with and without the filter, playing in Roon?

My second question would be... For a near-field monitoring situation like this one, is there value in eliminating the room? Am I wrong in trying to further DSP these speakers? I'm a bit worried because with the Audiolense guide, it seems each speaker driver corresponded to one audio interface output, while with the Genelecs, both L & R audio inputs feed into the subwoofer first.

 

I'd appreciate any and all help in this. Thank you in advance to anyone reading and replying, and sorry Mitch for highlighting you so many times.

[jrobbins50]

I recommend that you store the REW sweeps on your hard drive and play them back through Roon with convolution filters turned on for measurement. You’ll need to use the timing signal box in REW so the measurement sweeps begin to record when REW hears the timing signal. That way, you can confirm that your filters have smoothed your system response.

 

I have not bothered with this as I use Audiolense XO for two and multichannel filters and @mitchco has previously demonstrated that the predicted response improvement in Audiolense is consistently borne out in the results — so other than it sounds way better to me, I did not feel it necessary to prove out that the predicted results are the actual results. I already believe that.  But, if it’s what convinces you of the benefit of a software product like Audiolense, then go for it! Cheers. JCR 

[cjf]

On 8/2/2020 at 10:48 AM, VOBOSHI said:

m a bit worried because with the Audiolense guide, it seems each speaker driver corresponded to one audio interface output, while with the Genelecs, both L & R audio inputs feed into the subwoofer first.

Hello,

 

I may be misunderstanding your connectivity chain quoted above but it appears that the Motu is a 2 Channel DAC and its outputs are feeding directly into your Genelec Sub currently? I'm curious if the gear listed will allow you to not daisy chain the mains off the sub and if each speaker chassis Input (including the sub) can be connected independently. Also, can the subs internal bass management be fully defeated?

 

One can certainly reap very good rewards in a 2 channel system with room correction but depending on the flexibility of the kit mentioned there could be some roadblocks in the way.

 

Ideally you want to be able to control each speaker as a unique channel (which requires a multichannel dac) in order to best route the corrected signals from Audiolense (for example) to the proper speaker since in your case you have a third channel with the sub. If the kit will allow you to divorce each speaker from each other and you can flip a switch or turn a knob on the sub to kill or bypass its own built in processing capabilities then you can let the software do all its magic unhindered.

 

Audiolense probably wasn't happy about the DAC being a two channel unit....that is, depending on how the correction/filters/x-overs..etc was configured and routed in the program setup phase (ie..if you picked more than 2 channels as an example it may puke when it only  see's a two channel dac on the other end of the cable).

 

Your mention of near field listening does have strong merit in making this decision. You may find all of it to be just too much headache to take on. The setup and configuration of a properly done DRC implementation is not for the faint of heart unless you got some time to burn assuming your wanting to  do it as a self project. For some reason I enjoy spending weeks and months of my life on these kind of projects but I understand many folks don't 🙂