Digital Room Correction

I'm looking for some learned opinions on the benefits and short comings of digital room correction software. Any advice or experience you have with such software would be hugely appreciated.

Don't get me started... I promised myself I would be nice to everyone for a week or two, or maybe more.

I'm going for a bicycle ride.

:-)

The Edirol M-16 DX has this built in and it works. It is not perfect but it is far and away better then doing this with trial and error. I believe this and a well prepared acoustically treated room will get great results.  However a treated room is for many a luxury beyond their ability to realize. This can still help in those cases. 

I tried the RMC mode on my JBL monitors to see if that would help my room. No surprise that it didn't work. You have to fix the room. I've got some Real Traps and they help a lot. Still have a bad null at 160 hz because of the room dimentions. I could probably use some of those Real Traps corner jobs.
 
Check with the Real Traps guys. They can help you.
 
DaveT

the short version...

many (most?) acoustical problems in small rooms are caused by bad reflections and the room dimensions themselves. These are physical, time domain problems, and as such the actual errors will be different in different locations.

It is theoretically possible to apply the exact inverse of a transfer function to a signal, but that will not necessarily fix a time domain problem, in order to do that you need a frighteningly accurate, and detailed measurement. And at that point you are still correcting a time domain problem within the frequency domain.

This does not mean that all of the room correction designs are snake oil... there are cases, in a well designed room, where the room correcting software can help - think of it as the icing on the cake.

And therein lies one of the great ironies of the audio industry!

Consider all the "pro-sumer" gear with single-ended inputs and outputs. It can work, it can work really well, but it can only work when installed by a very knowledgeable person. Do the manufacturers target that person?

Flip side, consider a device designed for the pro marketplace, balanced I/O, proper grounding of the power feed and the shields, etc, and any idiot can hook it up and get great performance from it.

The same applies to finishing touches like room correcting speakers and symmetrical power distribution - they do make an improvement, but only when everything else is already right, and even then it's incremental.

If you have room problems you need to cure them at the source, not the symptom!

Two weeks ago my studio had some but not the best of room treatment.

However last week In installed an Auralex Roominator 2 kit the difference is remarkable.

The really nasty bass hump I had at one spot is now under control. I can hear across the entire spectrum very clearly

I do realise not everyone can afford such "luxuries", I can't, but now having experienced  some real treatment I can only say start by treating your room it really is the only way to go.

PS I have no experience with correction software.

This thread has me highly intreagued.  I have discovered that my tiny room is untreatable because of its tiny dimensions.  I had given up on it.  However, arc might give me a second lease of life if it is as good as everyone says.  On the subject of snake oil...I found that room treatment was exactly that.  I sent dimensions to Auralex who made me buy a bag of goodies.  It did not make much difference.  Later I found out that the issue was my room dimensions.
 
Only thing is that arc is kind of pricey.  Howver, I will have to bite the bullet.

wst3


A couple of thoughts before you spend (more of) your hard earned money...

First, one does get what one pays for, the free advice offered by Auralex and their competitors is a hit-or-miss deal. Sometimes they get it spot on, sometimes they don't... when they don't they seldom chase it down, as they are too busy answering new queries. I've always thought this was a bad idea, but you are the first person I've heard from that was completely dissatisfied.

Any kind of DSP solution is subject to not only the same rules that apply to physical correction, but a handful of mathematical oddities as well. Depending on your room construction it's entirely possible that a DSP solution won't work either.

In general, room correction software will only add that last 2%, it usually requires that most of the big acoustical problems are already resolved. Specifically, early reflections are darned difficult to cancel out with DSP.

And here's the part that bothers me... I've worked in some really tiny rooms, spaces that had absolutely no right to work, and yet they did. They were designed by a guy who learned the dark arts in Europe in the 1970s, when small control rooms were the norm. He learned well... one room that sticks in mind was probably less than 8 feet from to back, and maybe 14 feet or a little more wide, and yet the stuff I worked on there translated beautifully to the rest of the world. And that space was crammed with gear, this was long before the advent of the DAW.

I won't spend a whole lot more time on it than anyone else for free, but if you want to post your room dimensions, wall construction details, etc I'll take a quick look.

Dimensions below:
 
 measure 8.5ftx6.5ft. The ceiling is only 6.5ft high

Do you think that arc would help?

oye!!!

That's a small room... and most of the bitflipper's answers would have been mine. I don't like to speak ill of others, but frankly I'm a little surprised Auralex even offered to sell you treatments, with those dimensions there is very little room to play.

But let's try anyway... can you provide the surface finishes, e.g. carpet, wood or concrete floor, sheetrock or wood walls, sheetrock or tile ceiling, etc.

Also, describe or sketch the loudspeaker & listener placements.

Is there room/patience to try building out one or two of the surfaces?

And can you give me a list of the stuff you bought from Auralex?

Great recordings have been made in some very small control rooms, it's a matter of fixing what can be fixed, and learning how to interpret what the room/loudspeaker system is telling you.

While I'd never intentionally do it again, I had to help a friend record a simple demo back when I was between studios. For grins I agreed to do it, even though I had to do it in my office, which was probably about 8' x 10' with an 8' ceiling (again with the dup'ed dimension!)

The good news was that I had listened to so much music while working there, and on decent book shelf speakers driven by a decent amplifier (I was single back then<G>) that I was able to do a decent mix. Not the best work I've ever done, and I really only got away with it because there was very little low end energy - just guitar and vocals.

And no, it wasn't easy, and yes, I spent a fair amount of time second-guessing myself. And even more time listening to the mixes in other locations.

To answer your last question, ARC or something similar might help with frequency response problems, but as Bit pointed out, an equalizer might do the trick. Physical treatments to re-route the early reflections is the only way you'll fix those. Since you already have some absorption product I'd probably see what you can do with that before spending more money on a software solution that I still think will provide limited benefits... and then only if we can get the loudspeakers into the near-field for real.

Ever thought about knocking down some walls<G>?

jacktheexcynic
i would see if one of the other vampires has a bigger coffin.

Funny... maybe a bit mean, but funny!