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Discussion in 'Archived Threads 2001-2004' started by gene avallon, Jan 1, 2002.
need a low freq test disk for new subs comming whats out there
Lots and lots of low-freq tests on the AVIA DVD, specially for subs.
do they give you one frequency at a time for about 15 sec i looked at the spec sheet and it said sweep what does that mean
Avia has a low frequency sweep,the frequency is displayed during the sweep in real time,the sweep is fairly fast.You can monitor the displayed frequency and watch the sound meter at the same time,its not difficult.
Sounds like you need the Autosounds 2000 or Stryke discs.
30s tracks each from 20 Hz to 98 Hz, in 1 Hz increments for Autosounds, and 20 to 20 kHz by 1/6 then 1/3 octave increments for the Stryke disc.
Rick- You got it!
My wish? 20 to 160 Hz by 1/20th's of an octave...
20,21,22, ..., 40, 42, 44, ..., 80, 84, 88, => 160 Hz.
60 data pts.
I personally don't believe that every 1/6th octaves gives you enough resolution. So I use the Autosounds 2000 disc from 20 to 98 Hz, and then the Stryke disc up to 160 Hz. (I use an 80 Hz crossover.)
I made my own disc. I couldn't see paying money for something I could do myself with a little bit of work. The main purpose is bass/sub calibration and equalization tones, but I added a few other things that may be useful. Here is a brief description of the CDR:
Track 1: 10 minutes of pink noise
Track 2: 1 minute long 10 to 100 Hz linear sweep
Track 3: 1 minute long 20-20K log sweep
Tracks 4-9: 50,180,360,1k,2k,6k Hz; each track has 10 sec in-phase, 10 sec out-of-phase, 10 sec in-phase
tracks 10-99: 30 seconds sine wave tones at track # frequency (eg. track #47 has 30 sec of 47 Hz, track 73 has 30 sec of 73 Hz, ...)
I purposely numbered tracks 10-99 so you just look at your CD player, and the track number is the tone freqency. When you have your reading, just skip to the next track. Many of the discs you buy don't have every Hz between 10 and 99, but I think it is better to have the fine increments. If you don't want a particular frequency - just skip tracks as you see fit.
I hear no clicks between sine tracks - they all start with and end at appropriate zero crossings and slopes.
The 6 tracks of in-out-in-phase things may not be useful, but I needed to fill up the track numbers before the sine waves!
Note that these are not calibrated levels for calibrating HT sustems - these are files for adjusting subs, EQ, room placement, speaker extension, hearing etc.
I use this CD since it extends from 10Hz to 100Hz in 5 second increments.
>Sounds like you need the Autosounds 2000 <
Where can I get Autosounds? thanks Bob
I maybe outta line here,but if the disc is not encoded in Dolby Digital,so the receiver processor will be in the correct mode ie: running bass management,those type of test disc's will not give you correct data,they would be correct for true stereo where bass management does not come into play.Avia has a low frequency sweep that is properly encoded,and its not difficult to use.
I think most people use the test CDs in stereo mode to find dips and peaks caused by room influences. You're right, it's not encoded in DD or DTS but for the purposes I mentioned I don't think it matters. The problem with Avia, which is a great disk, is that the sweeps go by too fast to get any accurate measurements.
BTW, the Autosound 2000 disk actually goes down to 10hz. I believe their site is www.autosound2000.com and the disk goes for 14.95 plus shipping.
Jimmy- My pre/pro, a Sony TA-E9000ES, *does* use the bass-management circuitry for 2 channel/stereo sources. I can turn it off if I want too.
Chris- Your disc actually is a lot like the Autosounds 2000 disc (for them, 10 - 98 track # = Hz freq).
How did you make it? Inquiring minds want to know?
I used Cool Edit 2000 for this - a nice, inexpensive audio editor. You can generate sine waves, and specify phase (independently for each channel). Just choosing whole number frequencies, and whole number tone lengths (30 seconds for me) results in smooth transitions at zero crossings from track to track.
I also generated pink noise in CE2000. I put a little fade in and out for that, and for the sweep tracks to avoid abrupt starts/stops. Not too difficult. You want a copy? - just let me know your address, and I'll be happy to mail you a CDR. If you already have the autosounds CD that you mentioned, you obviously don't need one!
I sure could use one of those discs. I have the stryke disk but I may need 1Hz incriments in the future.
Send me an email if you have time.
Chris- Drats. I've been using GoldWave as my audio editor. I just looked through it, and it doesn't seem to support making test discs. Will have to check some more...
=> Dude: Now I think GoldWave *does* support test tones. There's an "evaluate expression" thing where you basically put in the "equation" for the sounds that you want. I've emailed them for any "quick instructions" for how to do it, if it's what I think. I wouldn't have even looked for it though if you hadn't posted. Cheers!
I also have Goldwave - it is a great editor, better for some things than CE2000, not as good in others. I love the GUI for Goldwave - the icons, everything about the look. But the equation editor is a much harder way to create the tone etc, disc in my opinion, that is why I used CE2000. Thre EQ editor is super versatile, and a great tool, but not quick to use, at least for me!
If you don't get an answer to your email, the help does explain how to generate a sine wave at least.
If you decide it looks like too much of a pain in the ass, I'd be glad to mail you a CDR of my test disc. It won't be exactly what you want probably, but maybe it'll help. Let me know, and good luck!
I own about half a dozen audio programs - each one has it's place and use. Plus, I sleep better at night knowing I have all this cool software around to screw up my sound system.