I have recently purchased an SMS-1 to use with my Anthem AVM 30 and have a few questions/comments.

My system consists of the following :
- Anthem AVM 30
- Sherbourn 7/2100
- Velodyne SMS-1
- Rocket speakers (760s, 550 IIs, 200, ELTs - 7.1)
- Rocket Sub UFW-10 x 2
- Samsung 941 DVD (SACD/DVD-A)

blah, blah, blah.... and a bunch more stuff not related to this discussion, you get the idea.

Anyway, I currently have an SMS connected to the two RCA sub outs from the Anthem and I then run a stereo RCA cable to the two Rocket Subs, split each with a Y cabel at the sub end. This works, but I wanted to run a single XLR out of the Anthem into the SMS and then the XLR and RCA outs to the subs. AVS'rs seem to think this XLR/RCA output combo will be fine. Any thoughts here?

Prior to the SMS, I ran dual subs using XLR outs. I added the SMS and using the RCA outs, I now have a ground hum. So I need to find and correct that, for now I have lifted the ground to the subs. Does anyone make an XLR Y cabel? This may solve my ground loop hum.

On the Anthem, I have the XO set to 80 for Cinema mode. On the SMS, I have it also set to 80. I have read about defeating the SMS XO and only use the one in the pre. I tried this with less than favorable results. I can get a flat respone with both set to 80. Anyone have better results turning off the SMS XO?

For Music, I run the Anthem in Music mode with XO at 50, Center=none, Rears=none, sub = 2 Super - All Ch Stereo. So, front mains, side surrounds, & Subs. XO at 50 gives me more full range from the mains/sides, XO 50 gives me some Sub action for music playback. I notice that with this setup I cannot get as flat a curve over the XO 80 on Cinema. I guess this is because the Mains are kicking in at 50 and not controled by the SMS, right?

I tried moving the subs around the room a bit, although my placement options are few. They are currently stacked, and this gives me a best results (flater initail curve and more SPL). I tried to seperate them on each side of my display, and the curve went to heck. So they will remain stacked.

I'm sure I'll have a few more Questions related to using the SMS with my AVM as I play with it a bit more. Thanks for the comments.

There's no need to run two RCA sub outs to the SMS-1, since the sub output is mono anyway. I'd run a single cable from the AVM30 to the SMS-1. The SMS-1 does pass signals between the XLR and RCA connections, so you can connect the AVM30's balanced sub out to the SMS-1 and then send an unbalanced signal to a sub. XLR and RCA outs aren't an exceptionally appealing option, but I have seen some XLR splitters.

I'd recommend disabling the SMS-1's crossover and letting the Anthem handle it - having two crossovers in series at the same point is going to get you to a weird place when you consider the two crossover slopes. If you move the cursor to select the low pass crossover setting for the “Setup” preset (in the System Settings menu), press “SELECT” to edit the crossover, and then press “RESET,” the SMS-1 will turn the low pass crossover off.

Also... XLR splitter? Try these:
Sweetwater for $13
Cobalt Cable for $28 (pick 12" and XLR female / two XLR male)
Parts Express splitter box for $25 plus a cable between the SMS-1 and the box

Thanks gonk, I have a 1M balanced cable arriving this week, so I'll go XLR out on the AVM to the SMS XLR LFE input. I may just then use unbalanced outs on the SMS to feed the subs. I wish they had included dual XLR outs on the SMS. (prob in the next release)

I did try to turn off the SMS Low Pass XO during one of my tuning sessions, but I got better results with it on, go figure? I'll give it another try this week after my cable arrives.

Keep in mind that by using the crossover when you're feeding the SMS-1 a sub signal, the LFE track of 5.1 material is being crossed over and anything above the SMS-1's crossover is being discarded entirely. If you leave the SMS-1's crossover on, you might bump the crossover up to 200Hz or so.

Excellent, thanks for the links.

>>If you leave the SMS-1's crossover on, you might bump the crossover up to 200Hz or so.

I can actually turn off the XO on the AVM... rather than set it at 200. But I'd rather use the AVM and turn off the SMS, as curt recommends on AVS.

once I get my balanced cable, I'll give it another try with the SMS XO off.

If you turn the crossover off on the AVM30, you'd need to also turn the sub off and route the left and right channels through the SMS-1 - that way, the LFE track would get merged in with the mains' signals, the SMS-1 would split the signals low and high (80Hz fixed analog high-pass crossover on the high pass output for the mains and the adjustable low-pass crossover for the sub), and you wouldn't have to worry about data getting lost in the crossovers. I agree with Curt from AVS - either disable the SMS-1's crossover entirely for a home theater application like this, or at least push the crossover all the way up to 200Hz.

No, I'm not going to route L/R thru the SMS. I am using all balanced connections on the AVM to the amp and want to keep it that way. I'll keep using the AVM XO and turn off the SMS.

Also, I am finally able to see the value of the AVM notch filter, now that I can graph it on the SMS. I have a peak near 80, so I have applied the filter on the AVM with favorable results.

The SMS is way cool, but I think it brings out the perpetual tweaker in me, never being quite satisfied. My family is growing concerned when all they hear is the SMS sweep tones for extended periods.

Can you comment on the differnt contour values of the factory presets and what affect they have. Default setting being #4, but Custom setting #5 has a different value for contour. Should I leave my default to 4 or go with 5 after I calibrate?

Each preset's contour acts like an extra EQ channel - set the frequency that it's applied at and the amount of boost or reduction. I keep my contour level at 0dB (effectively disabling it).