I was using a test DVD with some test tones for LFE and I was messing with bass management on the 990 and discovered a problem. My mains are set to Large and sub is set to none. I was listening to a LFE test tone designed to adjust the level of the LFE channel and changing the crossover when I ran into a problem. When I change the crossover for the front L/R the output level of the LFE test tone changes. If it is set to 40 the level is low. As I increase the crossover freq the level increases and I hear higher pitched sound. Why is this? If the sub is set to none then the crossover freq shouldn’t make any difference whatsoever. If this is working as designed what should the xover freq be set to?

So, you're running an LFE signal into the system with mains set to "Large" and sub set to "None", right?

Is the sound then coming out of your sub or your mains?

How are you generating this signal? PC? DVD?

The way you have things set up, I would expecting nothing from the sub and no change in the mains output as crossover frequency is changed. I'm assuiming all other speakers (center, rears, etc.) are off.

I'm using a test DVD. It is a DD signal and the tones are designed to adjust the level of the LFE to match the levels of the other speakers. The LFE channel is being sent to the Fronts but it changes when I change the Xover freq for the fronts. Again, the fronts are set to "Large" and the sub is set to "none". I have a sub but I can't seam to get it set the way I want it. My fronts are solid down to 35hz and they sound best when fed a full range signal so I was just experimenting when I ran into this. I have a sub but it wasn't connected at all when I was trying it this way.

No sound is coming from the center and rears when listening to LFE test tone.

Hi Daryl,

That definitely sounds like a problem. What "mode" is in in at this point? "Dolby Digital"? If you are just playing this one signal through the 990, and mains are set to large and the *only* change you are making is crossover frequency, and all other speakers are off, then you should hear no difference in the main output.

I see you had input on my thread here: http://ubb.outlawaudio.com/cgi-bin/ubb/ultimatebb.cgi?/ubb/get_topic/f/34/t/001287.html

Steve at Outlaw is working to replicate the issue. If you look at my last post at that thread, there is a link to some frequency sweeps. Do you have the setup to do some type of measurement like that?

I have a Radio Shack SPL meter and the test DVD I was using yesterday was one I downloaded that was created by swithey at AVS.

http://www.avsforum.com/avs-vb/showthread.php?t=742969

It has tones to help calibrate your sub (2 channel PCM) and a different set of tones to cal the LFE, which is a Dolby Digital signal. It was when using the LFE tones that I ran into this problem.

Interesting situation. Just for clarity, when you are running the tone can you hit Dolby Modes once to ensure the display on the 990 actually reads out DOLBY DIGITAL? It just might be something to ensure to aid in troubleshooting. The only reason I mention it is because I have situations where I put in a DVD, choose the Dolby Digital track for the movie, the movie starts, and it is in Pro Logic (not DD). If I hit Dobly Modes it'll go into DOLBY DIGITAL and in fact I can't go back to Pro Logic.
But informing Outlaw of exact processing modes might help Outlaw in troubleshooting.

Yes, I have hit the Dolby button and the 990 reads Dolby Digital.

Last night I did more experimenting. I connected the LFE/sub rca jack
on the back of the 990 to the LFE input on my sub. I then set the sub
setting in the 990 to LFE Only and left the fronts at Large. Then I
played the LFE test tones from the test DVD again. All the sound was
coming from the sub as expected (the rest of the speakers were silent)
but if I increased the Xover freq for the fronts the sound got louder.
During this test I hit the DD button on the remote to make sure the 990
was reading Dolby Digital and it was. I also set the sub setting
on the 990 to LFE+L/R and the result was the same. I even set the Front L/R to small and the result was still the same.

Hi Daryl,

So...

You are sending an LFE signal to your 990. Mains are set large, sub is set to LFE.

All sound comes from sub, all other speakers are silent (what is the crossover frequency at this point?)

You increase crossover frequency for mains and the sound gets louder. (what's the crossover frequency at this point?)

Does the sound ever come from the mains? Or it just gets louder in the sub?

Sending a Dolby Digital LFE signal using a test DVD. Mains are set to "Large" and sub is set to "LFE Only".

The LFE test tone comes from the sub only no matter what I set the front xover freq to.

The sound gets progressivly louder as I increase the xover freq. In the end I left it at 40. If I change it from 40 to 200 it sounds so much stronger that I'm afraid that some damage may occur to my sub.