@captouch Mitch creates a DSP package called a Convolution Filter. He uses some very expensive audio software to do this ($20k). This software is way more powerful than any physical audio gear that is inserted in a processor loop.

As I mentioned before the Convolution Filter is a digital only solution. That is your CD player, and tuners are out of luck. It only works with a DAC.

You install the Convolution filter on a music server, which is a computer. In my case, I use ROON Core on a cheap computer and install the filters on that ROON Core server. ROON has a GUI to install the filters. The filter is in the signal path (not sure if that is bad) and applies the filter BEFORE the bits are sent to the DAC. Your streamer sends the modded bits to your DAC. The DAC is connected to your preamp.

In my opinion the best way to do DSP (but only digital sources)

BTW - what I describe in NOT ROON DSP. The same filter can work on JRiver which is completely different from ROON.

@yyzsantabarbara Thanks for the explanation.  I wrote to Mitch and we exchanged a couple of emails.

He referred me to a device that could be inserted into a processor loop and interface with a computer to make it work on all sources, though it was an open question on whether the device would play well with my particular process loop (impedance matching and all).

It would be an over $1100 solution for everything which could be worth it if there were no other ways to address my issues.  
 

But I do think my room is shaping up to be okay after all.  And Mitch said if I changed my speakers (which is always possible), the filters would need to be redone, so I need to be sure I’m both settled on my endgame speakers and have remaining issues that keep me from being happy with the sound without DSP.

It’ll take me some time to sort all that out.

OP, for a reasonably inexpensive DSP solution with more potential tricks in it's bag of, you might look at a Behringer DEQ2496....everything in a tape loop that you could potentially want and then some.  The calibrated mic it uses costs 25$....
I've 2 of the older 8024s' that allow me to 'run flat' in a variety of spaces they've been in without treatments....not perfect, but what is?

Sweetwater for new (free shipping); used might be 'out where, somewhere'...hard to mess up an eq.

Steep learning curve, but you'll learn a lot in the effort....:)

Cheers and good luck, J

OP:

For the record, room treatments and room correction are not equivalent.

Using a frequency response curve to determine if you need room treatments is only useful in the bass.  Above that the microphones won't integrate frequency response measurements over time the way we do.  You need time based plots for that.

Having said that, REW includes a room mode simulator but I find the AM Acoustics version free and easier to understand.

Now, as for EQ / Room Correction... the best you can usually do without bass traps is to clip peaks.  After that you raise the overall level of the bass to taste.

With bass traps that are effective at your problem frequencies you can mitigate both much better.

Point is, for your bass, use the simulator to make sure your speakers and listening location are away from the room modes you are finding.  Consider placing bass traps near the areas activated by those modes. 

As for the rest of your speakers, leave them alone, but in the mid to treble regions having appropriate mid/treble absorption and diffusion helps greatly with imaging and comfort levels.  Also taming reflections (which won't show up in a frequency graph) will make the room sound like you have much more bass.

@erik_squires 

Thank you, I’ll try the AM Acoustics version.

If I wanted to take time based plots, is that doable using reasonably priced tools, or is that a pro assessment job?

I did move my speakers to the 1/5 position from front and side walls, and LP to 1/3 position from back wall.  Seems to have helped some.  I’ll post the resulting curves soon.

I do have acoustic panels that I think could work for the mid/high frequencies.  Had no idea the FR curve and REW program was incapable of picking those up.

Do you have to spend big $ on something like GIK bass traps, or is there a more cost effective option vs spending $500 per bass trap - that can add up quickly!

Also, off topic, I had tried to send you a private message to ask about speakers as you had commented a fair amount on a particular brand and I wanted to ask your opinion on some things.  But I got a weird message about a moderator having to approve my message - not sure it was ever received by you.  Just sent another message now to try again.