HO driver noise

[spy8181]

I have a HO and MBM setup and during a couple of specific movie sceens i'm getting a terrible mechanical fluttering sound from the driver on the HO. During Ironman when he is escaping from the cave and in the very begining of Serinity there is some low rumbling dirty bass. It doesn't vary with volume or settings on the HO and otherwise it sound fine, the MBM seems fine and so do my mains when set to full range. I don't think there is any way I damaged the HO but who knows. If anyone has these movies throw them on and take a look at what I'm talking about because I'm going CRAZY.

[Pete_Hsu]

spy, how high is the volume knob on the sub amp, and where is the bass extension switch set at on the sub amp? What is the subwoofer channel level on your receiver?

Thanks

[spy8181]

I have run the setup two different ways:

Max output, both ports open, extension switch 22Hz/ no turbo, crossover in at 50Hz, volume at about 10-11 o'clock

Max extension, with turbo, extension switch 16Hz/ with turbo, crossover in at 50Hz, volume at half or 12 o'clock

Denon is set to 80Hz and LFE channel volume is at 0

[Pete_Hsu]

Thanks for the info spy.

Are you using any type of auto-eq on the receiver like Audyssey? If so, try temporarily disable that to see if that helps.

FYI, some blu ray discs have the LFE running quite "hot" relative to the main channels. You may have to back down on the subwoofer channel level on these scenes.

My recommendation is to set the volume knob on the HO and MBM to ~ 9 o'clock, and then adjust the subwoofer channel level in 1db increments to your tastes. Another thing you can try is to run the unit with turbo, with bass extension switch set to '2 port open' mode, which will give an overdamped (ie. more rolled off) response.

Sincerely,

[spy8181]

Thank you Pete for the quick help. I'm going to try a few different ideas and see what happens and pray to the Subwoofer God.