Looking for somebody to help analyze my room

zybar · « **on:** 16 Apr 2004, 04:15 am »

I am looking for somebody in the Tri-State area who has the equipment to do a better analysis than I can do with my Radio Shack meter and test cd's.

Please let me know the services that you provide and their associated costs.

Thanks.

George

Ethan Winer · « **Reply #1 on:** 16 Apr 2004, 02:00 pm »

George,

> I am looking for somebody in the Tri-State area <

I have the gear and I'm very close to you. If you're not in a big rush maybe some Saturday I can come by. Right now I'm swamped getting our new products ready for the Home Entertainment show next month, and writing two acoustics magazine articles that are both due ASAP.

If $150 is not a budget buster for you, and you have a computer near your audio rig, you could get the ETF program and test it yourself. The mike in the Radio Shack meter is not too bad for what it is and what it costs. Then you'd have the flexibility to test any time you want in the future, to see the effect of moving speakers and bass traps and other treatment. Since I got ETF I use it all the time to experiment with trap placement in my living room, and other such testing.

--Ethan

mgalusha · « **Reply #2 on:** 16 Apr 2004, 02:46 pm »

George,

I'm certainly not an acoustician but I second Ethan's recommendation of ETF. A very nice tool for not a ton of money.

Doing some experiments with it one day showed that moving my couch out about 4 inches from the wall smoothed out a nasty bass hump. Well worth the money IMO.

mike g

zybar · « **Reply #3 on:** 16 Apr 2004, 02:47 pm »

Can somebody provide a link?

How does it work?

George

zybar · « **Reply #4 on:** 16 Apr 2004, 02:54 pm »

Found the software...

Has anybody used their laptop instead of a desktop?

George

mgalusha · « **Reply #5 on:** 16 Apr 2004, 04:44 pm »

Geroge,

I run it on my old Dell laptop (800mhz) and it works just fine. Of of the slick things about ETF is that it compensates for any non lineraties in the sound card. Make sure you unplug the laptop power supply when testing, most of them produce some truly awful noise which is injected into your system. I also used ETF with an older 450mhz Toshiba and it worked fine with that machine as well.

Another handy and relatively inexpensive tool is TrueRTA - a 1/24 octave real time analyzer for your PC. It's available at: http://www.trueaudio.com/ The have a free version but it's only 1/3 octave and not very usefull for low frequencies. The cost is $100.00 and IMO is worth the money.

One last source for some nifty audio testing software is Dazy Web Labs. His stuff is all freeware. Some more usefull than others but the price is certainly right.

mike g

Ethan Winer · « **Reply #6 on:** 17 Apr 2004, 01:31 pm »

George,

> Has anybody used their laptop instead of a desktop? <

I use it on my big rig (Dell desktop) in my recording studio, and also on my newish Dell Inspiron 8500 laptop in my home theater. It works perfectly on both computers. But...

Here's one small warning about using ETF with a laptop: ETF requires separate Left and Right line inputs and outputs. If your laptop has only a single mono mike or line input you'll need an external sound card. I bought a SoundBlaster MP3 USB card ($40) at the recommendation of Doug Plumb from Acoustisoft. The problem I had is the USB spec requires USB ports to provide 500 milliamps of current, but the Dell puts out only 300 milliamps. (I wasted days tracking down that info!) This is clearly Dell's fault, but I ended up having to also buy a powered USB hub ($15 more) to get it all working.

If your sound card has separate Left and Right line inputs, or it can provide enough juice to power an external sound card, you'll have no trouble at all with ETF on your laptop.

--Ethan

zybar · « **Reply #7 on:** 17 Apr 2004, 01:39 pm »

Ethan,

Thanks for the info.

I am seriously considering getting the ETF software.

Since you are so close, I would still like you to come over when time permits. Maybe you can bring two more panels (since I want to add them anyway)?

I will give you a call next week and we can figure out a date. I understand it will be a ways out...

Thanks,

George

zybar · « **Reply #8 on:** 18 Apr 2004, 02:41 am »

Silly question...

How do I use the Rat Shack meter as a microphone?

If I wanted to get a mic, can you get one for less than $100? What model?

Thanks,

George

Ethan Winer · « **Reply #9 on:** 18 Apr 2004, 02:13 pm »

George,

> Since you are so close, I would still like you to come over when time permits. Maybe you can bring two more panels (since I want to add them anyway)? <

Sure.

> How do I use the Rat Shack meter as a microphone? <

Really easy. There's a line output jack on the side, and that's what you send to your computer's line input. The Scale knob sets the mike preamp gain, so turn you computer's Line Input source volume all the way up, and adjust the RS meter's Scale (or whatever they called the stepped knob) to get the right input level.

--Ethan

zybar · « **Reply #10 on:** 25 Apr 2004, 04:16 am »

Just wanted to thank Ethan for coming over and showing me the ETF program.

Besides being very knowledgable in acoustics, Ethan is a really nice guy.

I now have my work cut out for me as I have some serious peaks and valleys according to the graphs.

I amazed that a system can sound as good as it does with the way the numbers are.

I will try and post some of the graphs over the next few days.

If anybody has a laptop, I highly recommend the ETF software.

George

capo · « **Reply #11 on:** 25 Apr 2004, 04:53 am »

George,

I would definitely be interested in your graphs and other information on your quest to improve your room.

I purchased four minitraps recently and put them in the corners of my room. They have worked out very well.

I purchased the ETF software/mic/mic preamp also and soon will start doing some testing myself. I don't have a laptop, but fortunately I have an HTPC in my listening/viewing room that will do the trick

Ethan Winer · « **Reply #12 on:** 25 Apr 2004, 01:07 pm »

George,

I had a good time too. When you get a chance, come visit me and we can have a few real beers. I hear they're even better than the virtual kind.

> I amazed that a system can sound as good as it does with the way the numbers are. <

No kidding!

> If anybody has a laptop, I highly recommend the ETF software. <

Just so everyone is clear, ETF runs fine on regular computers (PC) too. I use it on the laptop connected to my HT system, and also on the desktop computer in my home recording studio.

--Ethan

zybar · « **Reply #13 on:** 25 Apr 2004, 04:34 pm »

Here is my low frequency waterfall graph:

As you can see, things don't look to good (but they actually sound pretty good). I can only imagine what it will sound like once I get things flattened out a bit.

George