Interesting information about digital room correction (DRC)

ctviggen · « **on:** 20 Dec 2005, 01:07 pm »

Including drawbacks:

http://www.duffroomcorrection.com/wiki/Main_Page

This also describes the operation of the TACT. It appears that they're creating a very complex finite impulse response (FIR) (and more) and performing convolution (in the frequency domain? not sure yet). And check this out! You can get freeware to do DRC:

http://drc-fir.sourceforge.net/doc/drc.html

What a great resource for those who truly want to know how something like the TACT operates.

jermmd · « **Reply #1 on:** 20 Dec 2005, 02:28 pm »

Thanks Bob, very interesting. The freeware HTPC stuff has been around for a while and is discussed at length on AVS forum. It's a little too complex for me right now but I'm convinced that the HTPC will take over the roll of all our components except the amp and speakers in the future. It already has for the computer savvy.

ctviggen · « **Reply #2 on:** 21 Dec 2005, 04:29 pm »

Joe,

Any clues on what an HTPC would cost? I'm interested in perhaps using the system in the link I showed above, but quiet PCs appear to be on the order of $1,200 or so. I think this is expensive. On the other hand, that system allows you to correct CD information, which means that I could take all my CDs and run them through the program. I'd take the output CD data and put that into an SB2 folder. The problem with this scenario (as opposed to building an HTPC having the ability to perform room correction on the fly) is that the data would only be valid for a single room. I'd have to have two SB2 folders, one with unmodified songs and one with modified songs.

ctviggen · « **Reply #3 on:** 21 Dec 2005, 05:40 pm »

By the way, after reading the main article about what's involved in DRC, I think the TACT might be a steal for the price. This is a very complex problem with a lot of issues, and the guy has done a ton of work. I'm just amazed that someone would offer something like this -- which I guarantee took many, many man-hours of time to develop -- for free. I'd have to at least charge some money (like shareware) for it. I'm thinking of loading Linux on my computer at home and trying this out on a song. If I could get his results, I'd have less than $50 (for the linux distribution) into something with results equivalent to the TACT.

hanguy · « **Reply #4 on:** 21 Dec 2005, 08:42 pm »

I started to use a HTPC for movies about 1 year ago, when I figured out my 3 year old video card gave me a better picture than my $3K video processor. I have since then modified a M-audio Transit to a point that combining with the PC, the sonic quality is better than my heavily modified transport about $2K+.

Compared to the high end equipment, the value of HTPC is undeniable as long as you choose your components wisely. Yes, a pre-made silent PC is relatively expensive but if you are experienced in putting a PC together, you can get an utterly quiet PC for less than $1K, depending on your video card needs.

Imagine, if a new standard emerges, like HD-DVD or Blue-ray, all you have to do is buy a drive, hook it up and you are set, instead of having to spend thousands to replace your source front end.

As to DRC, I have yet to try it with my PC as the process looks to be very involved. I will try that when I have some time. The cost of adding DRC is relatively attractive - about the cost of a good mic and mic amp. Oh yeah, my time too

Mike

ctviggen · « **Reply #5 on:** 21 Dec 2005, 08:50 pm »

Thanks, Mike. Initially, I think I would use it just as a DRC engine, then maybe a server, then think about video. I have a Proceed PMDT and board which currently does my video processing (480i to 480p, etc.). Although you bring up a good point -- I'm definitely headed down the road to projector, and I should plan on buying a PC that's good enough to go that route.