Hey folks,

I'm trying to get my 990 to integrate well with the Velodyne SMS-1. My system is:
990 pre/pro, 7500 amp, LFM-1EX sub
Martin Logan Vista (Fronts), Cinema (center), Vignette (Rears)

I jumped on the EX/SMS-1 deal a few weeks back, and haven't really gotten these to work ideally with the 990. It's close, but I'm trying to get the best of both worlds... great movie performance and great stereo performance.

Currently I have the 990 set as:
Front: Large
Center: Small, 80Hz
Surround: Small, 80Hz
Sub: LFE

When watching movies and television, I'm getting pretty much the performance I want. For music, I've been listening in Bypass mode and am really impressed with the 2-channel performance of the 990.

As I've recently added the subwoofer and SMS-1, I'm thinking it would be nice to make a 'music' curve on the SMS-1 and include the subwoofer in my stereo listening... just for some added punch in that bottom octave. But with the current settings, there's no signal at the 990's subwoofer output.

Two obvious solutions exist:
A: Change main speakers to "small", perhaps 40Hz crossover (speakers are -3dB at 43Hz).

B: Change subwoofer setting to "LR+Sub".

I've played around with the first option which is how I learned about the inaccuracies in the bass management matrix. I don't actually get a full range signal going to the front speakers, even in bypass mode. And while that would be okay in theory, the speakers just don't sound as good with the crossover activated. It's not just the bass response. I haven't used this setting in a few weeks, so I forget the exact issue, but suffice to say that the speakers sound a lot better as I have them now.

So thinking about the second option... how does LR+Sub work? If I feed the 990 with either an analog or digital stereo signal, what will go to the subwoofer? The matrix indicates either "As dictated by crossover" or "full range" depending on the scenario. What crossover setting drives this? Do I use the Front speaker crossover setting to determine the subwoofer crossover frequency when running in this mode, even with the fronts set to 'Large'?

I guess ideally I'd like the 990 to get out of my way. The SMS-1 is an incredible tool, but the 990 filters make it a lot harder to get the most out of the 990. Short of running a stereo (front L/R RCA) signal from the 990 directly to the SMS-1 to use for music, and hoping that the SMS-1 can switch between inputs, this LR+Sub seemed like the only real solution.

So before I clicked "Post", I called Velodyne to ask some questions about the SMS-1. The XLR LFE input and RCA inputs are not 'switchable' at all. However, Rob at Velodyne suggested I consider running the 990 as "Front: Large, No Subwoofer", and running the L/R RCAs into the SMS-1, and let the SMS-1 do all the bass management. Upside - lots of adjustability, including various programmable selections for different sources (movie vs. music), highly adjustable crossover frequencies and curves, etc. Downside... only one I can think of would be if the SMS-1 alters the beautiful sound I get without it in the signal path.

Any thoughts would certainly be appreciated!

- Jason

One other upside of running my L/R signal through the SMS-1: the SMS-1 EQ would be able to address a 50Hz 'bump' not only on the subwoofer channel, but also the fronts. Hrmm... I may have to try this...

- Jason

Well, it looks like Rob at Velodyne was incorrect. The high-pass output of the SMS-1 is fixed at 80Hz, -6dB/Octave. If it matched the low-pass slope and frequency that would be great, but it doesn't.

So I'm back to square one...

- Jason

My experience with integrating the SMS-1 in with the 990 suggested that keeping the 990 "in the way" for bass management was better, for several reasons. One was the nature of the high-pass output, which as you've discovered is a fixed 80Hz signal. The other is that by only feeding the subwoofer signal to the SMS-1, I am keeping the signal path for my front channels as simple as possible. As a result, I disabled the SMS-1's bass management - I use it solely to deal with equalization. I did bump the crossover on my fronts up from 60Hz to 80Hz so that the SMS-1 could help with a room effect just above 60Hz. With all four crossovers (fronts, center, side surrounds, and rear surrounds) at or above 80Hz, the only speaker operating near that problem spot is the sub, and the SMS-1 is correcting it, so "problem solved."

If you set your fronts to small, I'd recommend at least a 60Hz crossover. Even if you do cross them over lower than that, you should adjust the crossover to at least 80Hz when setting up the SMS-1 so that the SMS-1's test tones actually get to the sub.

Interesting approach, gonk - thanks. I heard some things when setting up the fronts as 'small' that I didn't like, so I assumed that filtering out more of the bass would only make things worse.

Your point about setting the crossovers high when setting up the SMS-1 is well taken, and spot on. I ended up setting them all at 200Hz when running the '321' test and initial manual EQing, and then tweaking further with everything playing as described above.

I'll give this method another shot.

Do you happen to know what "as dictated by crossover" means for the subwoofer signal if the fronts are set as Large? ie: does the Front speaker crossover setting control the low pass frequency for the sub in this case? ie: Digital Input, Fronts "Large", Sub "LR+Sub", matrix says "Front: Full Range; Sub: As dictated by crossover".

Thanks!

- Jason

Jason,

I have a similar setup to yours, see my sig line. I have yet to get my system perfected either. My situation is slightly different in that my fronts clearly are not large speakers so I am always employing the sub crossover through the 990.

Having said that I was wondering if maybe you couldn't just use both of the 990's outputs, i.e. run the balanced outputs to your amp and the RCA's to the SMS-1. In this way the fronts get the full range signal and you can use the SMS-1 to control the signal to the sub. Down side of this setup of course is that you would not be getting any of the sub signal from your other speakers, i.e. center and surrounds, which would have significant impact on your HT experience. Personally that would not be acceptable to me, but for 2 channel listening it should work.

If HT is important then I would go back and try the fronts set large and the sub set to LR+Sub. This will send signals from all speakers based on the 990 crossover points. I am not sure whether is sends the full range signal from the fronts, but I doubt that it matters as the SMS-1 Low Freq. Crossover will take care of that for you. Keep in mind that the SMS-1 LF Cross needs to set at least as high or maybe slightly higher then the highest crossover point configured on the 990.

I have my system setup pretty well. I am extremely impressed with the LFM-1 EX it is a real ass kicker! Yet, it can be quite musical as well so overall I am very pleased. The SMS-1 really helped to smooth out the overall low response of my system and was fairly easy to configure although it did take me several hours of testing and I feel like I may need to do quite a bit more before I am satisfied it is at its best.

Now here is a question that maybe Gonk can answer. I sound good on movies and I even have a real aggressive config that will really thump the low end for action movies with a lot of explosions or battle scenes. I have a great configuration for listening to may SACD as well as traditional 2 channel listening of my older CD's. My problem is that occasionally, particularly when I have company, I like to take some of my 2 channel media and play it using the using the 5 channel stereo option. When I do this the Sub output is way over driven. My first thought was to just create another config, after all I have 6, on the SMS-1 with the sub volume reduced. However, it does not seem to be uniform from CD to CD. I can range from -10 to -20 on the volume in order to get it back to a good sound. Any ideas?

Mark

If the fronts are large but you have other speakers that are set to small, the signal sent to the sub from those speakers is dictated by those crossovers. Also, I believe that if you have the set to get a copy of the front channels (L/R+Sub) then the crossover for the fronts is used to determine how much of those channels you get (even though the front channels aren't using that crossover point themselves).

gonk & Mark - Thanks, guys!! I've definitely got some testing ahead of me now. As it turns out, I also have another subwoofer to test... a Martin Logan Descent that I picked up locally. Should be interesting.

Mark - regarding your comment...
Naturally it's important to keep filters from 'stacking' and impacting one another. Fortunately the SMS-1 crossover CAN be disabled completely if needed, which is even better than fussing with the -3dB frequencies to keep from stacking the filters. It's not obvious in the menu, but it is covered in the SMS-1 manual.

- Jason

Don't forget to check out Outlaw's guide - it covers everything that's in the Velo manual but may be easier to find stuff in.