You should be able to still use the two channel trim, just don't exceed -15db total between it and the normal channel trim. The solution is to turn you sub amp gain down if you are getting close to the -15 limit.

Here's how I found it.
I had my 2 channel offset at -3 db.
Sub calibration tone jumps when going from -12 to -13. -16db total.

Change two channel offset -2db.
Sub calibration tone jumps when going from -13 to -14. -16db total.

Change two channel offset -1db.
Sub calibration tone jumps when going from -14 to -15. -16db total.

No two channel offset works. -15db total.

The levels must have changed somewhat because I hadn't touched my sub amp gain since calibrating with the old FW. I also have a very efficient room and powerful sub. I currently have my sub amp gain dialed down to about 1/4 and actually need to turn it down a little more to get the trim number to around 0 instead of negative.

Scott, all,

No problem, I can give you guys a call. But if I'm at 0 (or -1) for my sub level and -4 for 2-ch offset, I'm nowhere near the -15 dB level you describe.

-- Otto

Otto sounds to me like you sub is not turning on until it gets hit with the higher buggy signal. Have you tried raising your gain on the sub itself? Do you have an auto sensing sub? Just don't go near -15db total if you do raise the gain.

Oh yeah, sub's on and working when listening to music in "stereo", "bypass" and "upsample" modes. But when I use "Test"-"OK"-"OK" to trim the sub with the remote, I appear to get no change until -- BOOM -- at -12 dB or whatever.

Using the same song and method in "5-channel stereo", the sub trim via remote seems to work OK -- probably because the 990 has not applied any 2-ch sub offset in 5-ch mode, and the 2-ch offset is playing into this somehow.

I've never tried this during the channel calibration in the OSD, but I can try tonight. So far, I've only tried to trim the sub, via remote, while listening to a 2-channel mode.

--Otto

Obie_fl is right. I suspect you are bringing the sub trim down because you feel the bass in all channel stereo is too strong. However, all channel stereo is a bad mode to adjust sub level in because your asking the subwoofer to reproduce the L/R bass signal once for the mains, once for the center and once for each pair of surrounds.

Therefore, I suspect you are trimming the sub level well below what would be equal SPL's between your subwoofer and the other channels.

At this point, the sub trim is too low when the tone is generated. Once you move beyond -15dB of trim, the sub level jumps dramatically.

Best,

Scott

I am nowhere near a -15 dB sub adjustment before playing with trim.

Sub is on and playing the music prior to (and during) attempts at making adjustments. I wasn't sure at first, so I turned up the master volume and am 100% sure that the sub is operational with 2-ch music.

If I INCREASE the sub trim using the remote, I get zero increase in sub output (to +15 dB -- no change by ear or feel of the driver). If I decrease the sub trim with the remote (to -11 dB), I get no change (by ear or feel). At -12 I get a huge increase, as we all know.

I'm not saying that I know the answer, but I'm pretty sure that these are NOT the problem:

Sub is off
Sub is unplugged
Sub is broken
Sub auto-on circuitry does not work
Sub is not connected to 990
Sub volume is all the way down
Crossover is upside-down
Phase lock is cracked
Power is out
Power cable is broken
RCA cable is broken
etc., etc., etc.

I will double-check everything tonight.

Thanks!

-- Otto

Otto, I think I might know what your issue is:

Are your speakers are set to "large", and your sub is set to "LFE only"?

If so, and you try to make level changes to the sub during PCM playback, the trim levels can't have any impact on the sub level, because technically there is no sub!

However, when you do combine attenuation levels to below 15dB, the tone suddenly kicks in despite the fact it should not be there.

Please check this out and let me know.

Best,

Scott

This sounds like a problem that I had once, and that Steve straightened out for me. At least before the firmware upgrade, one had to be in a surround mode before entering the channel calibration set up, or the sub trim will do nothing. Also one needs to be in a 2-ch mode (stereo, upsample...) before entering the 2-ch sub offset part of the setup menu before changing it. Steve also suggested I turn my sub gain (volume) way down so I would not need to have a -12 dB sub level and so the 2-ch sub trim could be useful over its whole range.

Well, I played with this some more last night. Sadly, I was not able to reproduce the problem I have described where I get no change when trying to trim the sub value via remote. Indeed, I measured pink noise output from 0 to +15 dB with the volume control vs 0 to +15 dB with the sub trim control (all other speakers OFF). There was no difference with my digital RS SPL meter.

So it looks like I made a mistake. The sub trim is working in my system on 2-channel stereo modes. The issue of the all sub attenuations combining to be greater than -15 dB still exists, but the trim seems to be working.

My thanks and apologies to the Outlaws!

-- Otto

Hey Otto I don't think you should apologize, although you may not have had the problem you thought you had, you did get me and Scott to investigate a pretty nasty little bug. In fact I'd like to thank you as it forced me to investigate the problem since I originally had misdiagnosed it too.