amp freq setting?

Dyohn,

Will this really work for setting the LPF to 80hz or 100hz?

I've posted this a few times on here.  Make yourself a test tone CD using a program like  Frequency Generator.  Select sine waves, enter the value of Hz you want to record, set to 0 db......use the Help file for specifics.  With this program, which I've used to make a CD (but can't use anymore now that the free trial is over), you make .wav files of frequencies at whatever duration you want.  I've been using the test CD for setting gain and also setting crossover freqs.  You have a lot of room on a CD, so make the files long enough so that you can work on the system without having to run up and push repeat over and over.

The trick when setting crossovers is to have many freqs recorded in sequence...such as 75, 77, 79, 80, 81, 83 (Hz)...etc.  You get the picture.  As the tracks of the CD play through in sequence, and you are adjusting the crossover, you want to get to a point where the 80 Hz track (if that is what you are adjusting to...in this case as lowpass for the sub) is just noticeably softer than the 81 Hz tone.  This would be like a crossover normally crossing a frequency at -3 db.  Then, compare the 81 to something like the 85 Hz....they should be the same loudness.  Check the 77 Hz, it should be even softer than the 79, and so forth.  There, you have adjusted to 80 Hz.

You can use a variety of CD burning programs to make the CD.  And a note of caution:  playing a sine wave for very long will burn up a speaker.  If you start smelling an odor turn everything off until later.  I smelled the burning odor for quite awhile when I first tried this before it finally dawned on me it was the speakers!  But no harm came to them.

A side note:  I didn't realize I should look for db setting, so when I made mine I don't know if I had the tones set to 0 db.  And now I can't use that nice easy program again without paying.  So I'll wonder about whether its right until I get another test CD made...

Yeah, 30 secs would be plenty of time. 5 to10 seconds would probably be more realistic for setting crossovers.  But if you want to set to 80 make sure you have freqs below that recorded, too.

A couple of longer tracks are good for setting gain, because you need to be able to read the meter, hold the probes, all that.  One for subs, another for the mids/highs.  Those tracks should be a good 30 seconds long.

I'll correct this here.  What I was describing was actually for setting high pass for the mids/highs....for the sub would be a bit different, with the higher tones less audible and the lower ones the same.