CurtPalme.com Home Theater Forum

AFryia · Posted: Sat Aug 02, 2008 9:12 pm Post subject: TrueRTA and First Reflections

Can TrueRTA distingusih the frequency of the sound coming from the first reflection point?

I'm looking building sound panels and wanted to figure out what frequencies to tune to.

This is a 1/24 oct reading green=noise floor, purple=pink Noise all speakers, orange=pink noise no sub.

fireanimal · Joined: 17 Jul 2007 Posts: 231 Location: Stayner, ON

You have to use the RTC60 graph for first reflections, and do a sweep. It will tell you how many ms that the reflection is away from the original, and give you an idea on were to place your panels.

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

I'd love to do a scan of my HT like that, but I can't quite see spending $99 for the 1/24 octave version. And the freebie version has only 1 octave resoluation, which is pretty useless. Are any of the free Windows-based packages any good, e.g. RightMark or BlueCat?

fireanimal · Joined: 17 Jul 2007 Posts: 231 Location: Stayner, ON

Sorry my mistake, you should be using RoomEq Wizard which is a free download @ hometheatershack

AFryia · Posted: Mon Aug 04, 2008 12:42 am Post subject:

fireanimal · Joined: 17 Jul 2007 Posts: 231 Location: Stayner, ON

No, I made a mistake. The best software to use for this is RoomEq Wizard. You run a sweep, and then analize all the different graphs. You need to read the impulse response graph to see were the reflections are. The RT60 graph will give you a good idea of your overall reverb times.

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Cool, I've downloaded a copy of REW and will play with it sometime in my copious free time. (Like, maybe next April!??)

Tnx for the pointer!

AFryia · Posted: Tue Aug 05, 2008 2:23 am Post subject:

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

here is aneat spread sheet for figuring out where you rooms frequency dead spots might be.

Reader David Henderson Provides a Spreadsheet to Calculate Room Acoustic Measurements

Athanasios

fireanimal · Joined: 17 Jul 2007 Posts: 231 Location: Stayner, ON

Other then reading through the forums over there, that's about it. It does seem hard at first, but it is a very easy software package to use.

AFryia · Posted: Tue Aug 05, 2008 10:50 pm Post subject:

Athanasios,

I have a couple of those spread sheets.

The problem is that my room is a media room not a dedicated theater. My room is far from ideal, the room is not semtrical, the seating is off center and there are overhead sofits. I don't know how accurate the spread sheet would be in my case.

So I'm hoping to measure the resonance, nulls and peaks.