Creating a 20Hz test tone on one or two channels

ctviggen · « **on:** 24 Jan 2005, 05:46 pm »

Is there a way to create a bass-heavy test tone (say, 20 Hz) on one or both channels of a system? In other words, I'd burn a CD having this test tone and then test my system using the CD. I'm having troubles getting my Proceed AVP to use both of the stereo subs when in stereo mode. However, I can't tell whether I'm just selecting music that doesn't have low bass in one channel (I doubt it, but I'd like to rule this out). (I have Avia, but the AVP correctly uses both subs in prologic, just not in stereo.)

Thanks!

Tonto Yoder · « **Reply #1 on:** 24 Jan 2005, 06:00 pm »

Not exactly what you want, but there's a multimedia speaker test that has a 30Hz tone (not sure if it's two channel, or alternately left and right).
Maybe you could burn a CD on your computer and play it on your main system.

bubba966 · « **Reply #2 on:** 24 Jan 2005, 06:16 pm »

Why don't you just turn prologic off & run Avia in straight stereo?

MaxCast · « **Reply #3 on:** 24 Jan 2005, 06:58 pm »

How would it *not* play through both subs? Do you have two sub outs and maybe they don't output in stereo?

ctviggen · « **Reply #4 on:** 24 Jan 2005, 07:04 pm »

Tonto,

Thanks! That should work.

Bubba,

That's a good point. I'm just not sure that it would work. When I force stero mode (called "2 channel, surround off") when using the AVP as a DAC, the subs fail (only the left one plays). I may try to do some additional settings or even return the AVP to its original programming in order to test these things.

ctviggen · « **Reply #5 on:** 24 Jan 2005, 07:12 pm »

Maxcast, here's what happens. I set the AVP for stereo subs. I connect the two subs to two separate outputs (one for R, one for L). I go into the menu for setting speaker levels. Each sub plays when the sub is selected in this menu. When I ran Avia, the left sub played perfectly; the right sub (for whatever reason) need to be increased to about +10db. If I play a DVD or use "5 channel stereo" fake stereo setting, I can feel both subs moving. If I put in a CD (or choose "2 channel, surround off"), only the left sub will move. The right sub does not move. I've used several songs to test this. I've modified the settings for "2 channel, surround off" to be "default" subs and "force on" for the subs. Regardless, only the left sub plays. The problem is that I don't really know how much low bass is in my test songs, and it'd be easier, while I'm looking for answers (although I'm thinking now it's a bug and the AVP really doesn't do stereo subs or my AVP is bad), to play something I know has low bass.

rosconey · « **Reply #6 on:** 24 Jan 2005, 07:26 pm »

sounds like a pre problem or your unit sums the signal automaticly for stereo-email them and find out.

jermmd · « **Reply #7 on:** 24 Jan 2005, 07:29 pm »

Bob,

I still have your test disc with the 20hz (stereo) tones on it. Could you describe your set up again. I know you have an SVS sub (powered?) and a VMPS sub (outboard amp?). How is everything connected? Is the problem definitely isolated to the AVP? Switch interconnects from right to Left and play stereo. Is the right sub now the one that plays?

Joe M.

ctviggen · « **Reply #8 on:** 24 Jan 2005, 07:46 pm »

Hey Joe,

I now have two Larger subs and an amp driving both of them. I take the supposed output for the left sub and put it into one channel of the amp, then use that channel to drive one sub. I take the output for the right sub and put it into another channel of the amp and use the second channel to drive the right sub. In short, when I use the internal test tones for the AVP, both subs work perfectly. When I play a CD, only the left sub appears to work. I didn't try to switch the connections, because both subs seem to work with the internal test tones of the AVP (i.e., I select "right sub" and the right sub puts out a tone; I select "left sub" and the left sub puts out a tone). I've tried the exact same setup with my SVS sub, and the same thing happened. However, I upgraded the AVP software and was hoping this was fixed (some bugs are fixed by the new software).

When I use Avia, both subs appear to work (although the right sub needs to be set higher in dB for some reason). When I switch to "2 channel stereo, surround off" only the left sub appears to work. The manual for my AVP says the following:

Stereo Subs: you may also elect to use stereo subwoofers, in which
case the regular sub output will handle the left and Aux 1 handles
the right. Specifically, any bass information in a “left” speaker (front,
side or rear) that has been set to x-over will be reproduced in the
left subwoofer; likewise for the “right” speakers and the right
subwoofer. Bass from either the low frequency effects channel (also
called the “.1” channel) or from a center speaker set to x-over will
be split evenly between the left and right subwoofers.

You can also change the settings with the "2 channel stereo, surround off" to default (uses sub settings in the speaker menu), force sub on, and force sub off. I've tried both force sub on and default and neither setting will produce sound from the right sub while in 2 channel stereo. Again, though, without a test disk, I can't really be sure that the music I'm playing has low bass on both right and left channels.

I was going to email you about the CD, but last night was the first time I set everything up, and I don't really need anything but one tone.

jqp · « **Reply #9 on:** 24 Jan 2005, 08:52 pm »

While you're at it make a test tone of 18 or 17Hz also since the Largers should be able to produce those frequencies. You won't hear anything but you could feel it and see the cone flutter.

jermmd · « **Reply #10 on:** 25 Jan 2005, 12:39 am »

Bob,

Well, I'm not sure what the problem is with the subs. Call me if George is going to be around and the three of us can brainstorm. Let me know how you want me to get you the test tone disc.
I bought the ACI Maestro and it is awesome. I have no need for stereo subs and I have more clean bass than I will ever need. It can not be localized even when crossed over at 80 hz. I can't wait for you to hear it integrated with my RM30's.

Joe

MaxCast · « **Reply #11 on:** 25 Jan 2005, 02:36 pm »

Sounds like a software issue in the preamp to me. I also don't think the sub levels should be that far off. Other than some room gain/position issues they should be pretty close.

ctviggen · « **Reply #12 on:** 25 Jan 2005, 03:08 pm »

Joe,

I would like to come over sometime. What about this Saturday? I can be over after my bike ride. I could get the CDs and test out my system that day, too, as I probably won't have time to do so until then.

Maxcast,

I think you're right -- I just want to do some further checking to be 100% sure of this. After that, I can just choose one sub and split the sub signal to both subs. I'll decide later whether to upgrade (maybe to the AVP II, as I like the AVP and haven't had any troubles with it until now; I can always use it as my "upstairs" preamp). (I'm just sick of the "upgrade-itis" and would like to get out of the loop for a while.)