Until a few days ago, I was pleased with the audio and video playback of my HT. I must admit though, "I'm a tweak head!" For some reason I always feel if I made one more tweak, it would look or sound better. Anyway, both the ML Aeon i's and Descent came with the patent ML spikes. However, I didn't feel the need to install them because it already sounded great.

Well hold on to your seats boys and girls (speaking of girls, why aren't there any in forum)anyways, after installing the spikes on the fronts, I played one of my favorite movie and audio demos

David Benoit (Every Step of the Way) GRP, track 3 Key to You and 4 Remember what you Said David Benoit, Every Step of the Way, GRP, track 3 - Key to You & 4 - Remember what you Said. I've loved this CD since the time of purchase (1988) but never have a heard it sound this good. Mind you now, I still haven't installed any acoustical panels or traps....I think many of you would be amazed on the tightness of my sound stage and detailed imaging. With the spikes added to Aeon's, they sound like a totally different speaker. In short, they've completely disappeared in the room. Even the wife notice!!! That's gotta stand for something! :-)

Then came Master and Commander, chapter 4 (Under Attack). All I could was take a deep breath, close my eyes and say, thank God for good sounding HT. I was again completely blown away at the detail now audible in my system. By far the cheapest tweak even done.

Now came the coup de gras; placing the spikes on the sub. Until now, I believed to get the tightest LFE from my sub was definitely going to require installing traps of some sort. I don't think I can put into words how excited I am about my system right now. The low end in my theater is so quick and tight, I had to lower the level a notch. I still may need to add a couple acoustical panels; definitely don't need traps, but on a scale from 1 to 10 my system is a 12

One question for the group. How do I determine the best setting for the ML Sub? These are the options:

Phase: 0, 90, 180, 270 (I have it set to 0)
Low Pass Filter: 40hz or 70hz (I have it set to 40hz)
Level: set to 5
25hz Level: 0 to +12bd or 0 to -12db (I have it set to 0)

For phase, the rule of thumb is usually to play a test tone and try each setting - the one that seems loudest is the one to use.

For the low pass filter, I'd either disable it or set it as high as possible - the 990 is providing you with bass management already, so you don't need a second crossover getting in the way. With the 40Hz setting (assuming for a moment that you don't have all of your crossovers in the 990 set to 40Hz as well), you are throwing away subwoofer signal - probably a lot of it. If there's a way to disable the crossover, use it. If there isn't (and with a max setting of 70Hz I really hope there is), set it as high as possible.

The level should be fine at 5. That's where I tend to start, and then fine-tune the sub trim in the processor's settings.

The 25Hz level sounds like an EQ at 25Hz. I'd probably leave it at 0 like you are.

Thanks Gonk. Unfortunately, there's no way to turn off the low pass filter. And set to 70hz, it gets really boomy..yuck. Other suggestions?

I was going to really be disappointed in Martin Logan if they had actually messed that up (home theater sub has to have a way to disable its crossovers), so I grabbed the Descent i manual . At least on the Descent i, the "LFE in" connection on the sub bypasses the low pass crossover. Then I realized that you have the original Descent (not the Descent i, which has a 50Hz filter and a couple other controls that you didn't mention having on your sub), so I chased down that manual . Sure enough, page 7 confirms that the LFE input still bypasses the low pass crossover (whew!). I'd recommend connecting the 990's subwoofer output to that input. ML also suggests using that 25Hz filter to tweak the sub if you are having trouble getting the sub and mains to blend together well (either too little bass or too much) - if you're getting "boomy" bass, you may need to try dialing the 25Hz filter down a bit. You might also tinker with the crossover settings in the 990.

WOW...you know, any other time I'd feel bad when people know more about my equipment than I do but for some reason this time I don't. Thanks Gonk...I'll make that change tonight and let the Outlaws know how it turned out.

Well Gonk, I made the change and was sadly disappointed. Bypassing the LowPass Filter in ML Descent and allowing the 990 to manage the bass was not pleasant. Now I'm not saying the 990's bass mgmt failed because I still haven't done the update :-( I know, shame on me but will doing the update really make a difference in performance or will it just provide more controlled mgmt?

After making the change, it was now apparent the sub was located in the right corner of my theater, it lost its quickness and suddenly became boomy. And increasing the level made it worse .....it sounded like my 1990 Kenwood rack system....don't mean to offend anyone. Bottom line, it wasn't good at all. Needless to say, I changed it back to allow the ML Sub to manage the bass and like that, I had my system back. Woohoo!!!

So school is open...besides yelling at me for not doing the update, what else should I do?

The update will only matter if you are operating in a way that runs afoul of some bugs - it's been long enough that I've forgotten what the problem arrangements were, but I don't think your system is currently one of them (although they did also do some nice things in that firmware update ).

Two questions about your current setup: what crossover points are you using on the 990, and what crossover point are you using on the Descent?

990 setup:

small & 40hz on the fronts
small & 120hz on the center & surr
LFE Only for the Sub with the ML LowPass Filter set to 40hz

When you say "LFE Only" you are talking about the 990's subwoofer setting right? The sub cable is running to the Descent's left or right input? If that's the case, the one thing that I worry about is the fact that you are completely throwing away everything between 40Hz and 120Hz on the center and surround channels, plus anything above 40Hz in the LFE channel. Can you try the 70Hz setting on the Descent? That would at least decrease the size of the hole in your low frequency.

Yes....LFE only in the 990. Yes the sub cables are connected to the Descent left and right input. When I try the 70hz setting on the Descent, it gets boomy. Is there anything i can do to reduce the boom and accomplish what you're recommending?