My BFD experience.

[bikeman]

The BFD can store different curves right?

Yes. I only use one but many have posted using one for movies and one for music. There are more but I haven't read about anyone using more than two.

David

[Nicholas Mosher]

Yeah, I believe you can store up to 10 curves if you want that many...

Party mode
Quiet mode
etc...

[curtis]

Now I am wondering again if it would be worth while to get some measurement software like ETF or TrueRTA to watch changes in realtime rather than single measurements and plotting.

[Nicholas Mosher]

Ehhh...
Then you need the software, fancy microphone, tripod for said microphone, hours for learning the new software, etc...

Just read Sonny's guide...
http://www.snapbug.ws/bfd.htm

After you set one filter you don't even need the guide anymore, its so easy.

EDIT: I just use one curve for everything. Set it to sound good with music, and movies will sound equally fantastic!

[BradJudy]

Now I am wondering again if it would be worth while to get some measurement software like ETF or TrueRTA to watch changes in realtime rather than single measurements and plotting.

Haha - I thought I just convinced you NOT to buy that. For what it's worth, you can stop by and borrow mine.

Here is a thread with some pointers on free audio software: http://forum.av123.com/showthread.php?s=&threadid=7809 I just downloaded a few of them to try out (I already had the free version of TrueRTA). I have to double-check, but the trial version of ETF might be enough to do basic measurements as well. Even with free software, an ECM8000 mic and pre-amp will run about $100.

I agree with the earlier comment to use at least 1/6 octave tones. I downloaded a good set of 1/12 octave tones that someone on AV123 posted. That is what I used for my recent measurements using the RS SPL meter. I also agree that you should measure well beyond the crossover point (see my measurement post). You may or may not be able to fix problems in that range, but it will certainly show any phase mismatch with the mains.

[curtis]

Both software companies say the RS meter used as a mic is good enough for subwoofer EQing, I have a tripod, and I am told the software is not that difficult to learn.

Then again...it is another $100-$150 for the software...and I would need some more cables.

[curtis]

Thanks Brad....

If the weather is not good on Saturday.....it is going to be my project.

I emailed one of the engineers at Hsu, and he also said that anything less than 1/6 octave is not good for correcting low frequency room anamolies...and could actually hurt response.

The realtime aquisition is what draws me to use the software and my laptop.

[BradJudy]

Curtis,

I haven't tried the RS meter as an input for the software. I like how ETF can use a loopback in the second channel to remove the soundcard from the equation.

As I said, you might be able to get away with using the trial version of ETF for measurements. Basically, it limits you to only two measurements per session (it can get annoying pretty quickly), but I think the functions are mostly (if not all) there. I like that ETF takes about 5 seconds to run a measurement, so it's quick and easy to do repeat measurements while you tweak. It isn't as intuititve as TrueRTA, but I could do some quick instructions. TrueRTA is pretty easy to use, but you have to pay $100 to get the 1/12 octave resolution. I should do some tests with ETF using the ECM8000 and comparing it to the RS meter also using ETF (my other comparisons were with the RS meter using the manual test-tone method).

[curtis]

basicly...it is $100 for TrueRTA or $150 for ETF, $100 for mic-preamp/mic, and possibly an external soundcard for the laptop...and cables.

I'll think about it some more.

[Mag_Neato]

The two discs I have with tones have the same freq. steps....1/3 octave....so the next step after 80hz is 100hz, then 125Hz. I will redo the measurements and run them to 160Hz.

If I am using an 80Hz crossover, what effect will the BFD have on freq's above that? It will be in the sub path, not the mains.

I will be getting the BFD tomorrow.