User experiences on Velodyne SMS-1 - Page 4

FuzzMeasure will do the same on a Mac.


Not if you do a modern best practices system design and use multiple subwoofers placed around the room and electronic EQ! And for those pursuing an upgrade path the order should be first multisubs, then EQ. Multiple subwoofers (they don't have to be that big or powerful individually) will provide a greater advantage than EQ with a single sub, so start with the big improvement first and refine later.

Of course, if one compromises then the results are bound to be suboptimal. For movies, that might not matter so much because one just cares about the size and scope of the fake boom. For music the difference between flat/clean/extended bass around the room and a single subwoofer are instantly apparent.

Old thread. Re-reading some of my previous posts, I would like to update my experiences with the SMS-1 since then. I have changed subwoofers to a pair of Seaton Sound Submersives. I've also acquired a room acoustical analysis program called xtz Room Analyzer:
http://www.xtz.se/produkt.php?allman...kt=41&eng=true
This program can measure frequency response as well as time response. I am using Audyssey MultEQ XT and then the SMS-1 to tweak the Audyssey result to my liking.

The following is my before and after response:

Before:


After:


(Note that these curves are a 3-seat "averaged" response.)

Obviously the FR is flatter after the EQ's were applied, and the SMS-1 is primarily responsible for that. However, Audyssey had a huge effect in the time domain response as seen in the (small) "Time/Frequency/Magnitude" graphs in the upper right corners. These depict the time response in the room, the "overhang", if you will. Note how much less overhang there is across the entire bass spectrum.

I ran Audyssey first, with the SMS-1 set for "flat" response. This allowed Audyssey to account for the latency of the SMS-1 and set the distance setting appropriately. Then, when Audyssey was finished, I used the SMS-1 to fine tune the FR.

The sound is fantastic, definitely the best, tightest, most tuneful bass I've ever had in my room. For music, the sealed Submersives mated with my sealed Atlantic Technology 8200e speakers provide a seamless blend at the crossover, (100 Hz), and bass that just fills the room without bloat or boominess or muddiness. I attribute this to the decreased reverbation time provided by Audysey. For movies, the subsonic extension of the Submersives coupled with their massive output capabilities provide all the shaking, rattling and percussiveness you could want.

For a long time, I was leery about "cascading" multiple EQ's. I have gotten over it.

Craig

While I agree that multiple subs are always better than one, I don't agree that one can forgo EQ, especially time-based EQ like Audyssey. Multiple subs can help flatten the FR, but they won't decrease the decay time in the room. Only acoustic treatments and time-domain correction can do that. IME, time-domain correction is more important than flat FR.


IME, long decay times, ringing, overhang, etc. do more damage to the sound of the bass in a room than does uneven FR. IMO, one should FIRST fix the room acoustically, then use electronic, time-domain EQ to fix the time-domain response... THEN fix the FR.

Craig

I keep coming back to this graph



Three subs, Geddes-style placement, note the location of the sliders.


I think that, with placement, one can address both. That said, the combination of MultEQ XT (or similarly capable system) in the receiver with multisubs and at least some parametric sub EQ is probably the gold standard. I've never heard better, at any rate. And thanks for your measurements of post-Audyssey EQ. There's an awful lot of mysticism on the Audyssey thread about that kind of thing...

OK, I don't have Audyssey. I just have a Z7 with YPAO, which I understand isn't as good. I don't wish to buy a new receiver or an Audyssey unit, so should I run YPAO before the SMS-1 or just go with the SMS-1?

Well, Audyssey (from what I can infer based on provided measurements; they're too classy to out-and-out name competitors) didn't fare too well in Harman's blind listening comparisons of room correction systems, so who knows? What I would do, as described by craig john, supra, is first EQ the sub, then run YPAO. Then, if you want to change the sub further, just go back to the SMS-1 and do it. That way, the level-setting function of YPAO will be more accurate, as you'll know that the crossover/level isn't being impacted by peaks/nulls in the sub's FR. (Or, if you know you do have big peaks/nulls in the crossover region, you can manually adjust levels to compensate.)

PS: That particular measurement was done when I was using a Panasonic XR55 receiver that had no EQ capability at all. (And vented "pro audio" subs - a Tannoy B475 and twin vented subs with JBL 2235H's - hence the rolloff in the 20s.)

Thanks for the link to that interesting study and for the advice.

The really interesting part to me (as someone new to this) was the following conclusion from the study:

"A flat in-room target response is clearly not the optimal target curve for room equalization. The preferred room corrections have a target response that has a smooth downward slope with increasing frequency. This tells us that listeners prefer a certain amount of natural room gain. Removing the room gain, makes the reproduced music sound unnatural, and too thin, according to these listeners. This also makes perfect sense since the recording was likely mixed in room where the room gain was also not removed; therefore, to remove it from the consumers' listening room would destroy spectral balance of the music as intended by the artist".

So perfectly flat isn't so "perfect" after all?...

I must have missed something here.

Harman's paper didn't name any developers/manufacturers, so how do you know where Audyssey ranked?

I would like to know where these systems rank, though.

I want to clarify something from my post above. Before I run Audyssey MultEQ XT, I set the SMS-1 to Preset 6 which is "EQ Defeat". Therefore, it is in the circuit, but not EQ'ing anything. Audyssey can measure the latency of the SMS-1 and set the distance setting appropriately and do it's time/frequency correction. THEN, the SMS-1 is used to "tweak" the FR to a little flatter, and to invoke the slight rise of the lower range, (I like a little "house curve".)

Craig

That's a nice flat *frequency* response, but the SMS-1 doesn't measure the *time* response. You *might* still have some serious ringing that is not shown on the SMS-1 display. (Since you're using Audyssey, I'm not saying you do, but you might.) The SMS-1 just can't tell you that. You need something that can look at the response over time.

BTW, it's interesting that I put the SMS-1 mic right next to the xtz mic. The frequency response curves were virtually the same, verifying to me that both systems are accurate.

Craig

Craig, do you have measurements that show the difference in FR with and without the SMS-1 in your system, ie. just using Audyssey?

Me too. This is where I had to fine tune those lower frequencies by ear. Not too much and not too little. Once I got it, I didn't want to touch anything.

I like the house curve as well. That is the charm of the SMS-1 compared to the EQ1.

Hi Curtis,

I don't remember if I saved those, (or if I even did them), but I will check tonight. They would be on my laptop at home if I still have them.

If not, I can re-generate them. I might do that anyway and enlarge the Time/Frequency/Magnitude graphs. They are really quite interesting and different than what REW displays.

However, what I would rather not do, is to take the SMS-1 out of the system completely to re-measure Audyssey by itself. I would have to re-do Audyssey again and I have the system sounding so good right now, that I don't want to mess with that. I can re-measure the system with the SMS-1 set on Preset 6. Is that good enough?

Craig

I would run YPAO first with the SMS-1 set on Preset 6, (EQ Defeat), then run the SMS-1 on the result. Running YPAO first will set the levels, distances and crossovers. The SMS-1 EQ should be performed after those settings are in-place.

Editorial comment: I had a Yamaha receiver a few years ago. I did not care for the sound of the YPAO and I defeated the EQ it invoked. I just used YPAO for the level, distance and crossover settings, and I even changed the crossover on some channels from "Large" to 80 Hz. If you decide to defeat the YPAO EQ, do it before you do the SMS-1 EQ. The YPAO EQ "corrects" down to 63 Hz, so you don't want that in the system for your SMS-1 EQ if you later plan to change it.

Craig

Don't go through too much trouble. I was just interested in seeing how much difference the SMS-1 made, and if it was audible. I am curious because I am skeptical about throwing two sets of filters into the chain along with two sets of ADA conversions (but now that I think about it, I am not sure the SMS-1 works in the digital domain).

I have heard what Audyssey does to the bass a few times, and on a few different systems, and it has always done a great job.

If I'm reading you right, I could just skip YPAO entirely-- measure and enter the distances, set the levels with an SPL meter, and select a crossover in the Yamaha, then use the SMS-1 and manually adjust things to try to get the gradual downward sloping "house curve" (totally skipping any of the auto-eq routines). Right?

(The SMS-1 just got dropped off on my porch this AM, so I'll have a go at it within the week )

Sure you can do that, but then you won't have the correct distance setting for the subwoofer. YPAO measures the "acoustic distance" which, with the SMS-1 in the circuit, will be longer than the actual physical distance. This is to account for the latency in the SMS-1.


Have fun.

Craig

The SMS-1 is a digital EQ.


Agreed!

Craig

I use the SMS-1 and MultEQ XT in a similar way with my Integra SSP. The main difference is my SSP has two sub outs that I connect to two co-located sub pairs. Audyssey calibrates these pairs separately (levels and distance) and I have only one of the sub pairs connected to the SMS-1 (in no EQ Preset 6). I then use the SMS-1 to view the summed FR of all the subs and can EQ the one pair to taste.

This would work much better if the SMS-1 allowed two discreet sub ins and outs (SMS-2) but it gives me some utility and I like the convenience of the real time low frequency display of the SMS-1. Audyssey does most of the heavy lifting EQ wise and I can at least see what it has done and tweak within the limitations described above.

I put in an inqury to Velodyne regarding a proposed replacement for the SMS-1.
Alas, there is nothing in the pipline as of yet.

They are focussed on updating the DD line for next year. After that maybe...maybe.

But isn't the SMS included on the DD subs anyway? So if they update them they should update the SMS as well.

Nevertheless, there is always the Audyssey unit out there.

Yes, but, it will not be updated to include a second discrete input/ouput.

The Audyssey is too limited as well not allowing the user to adjust the settings.

Of course, this has been discussed at length in this thread and others. The Audyssey does not allow enough boost to the lowe end to emulate an LT circuit that is required for sealed alignments.

Can you use a separate SMS-1 for each sub if you want more control?

You can use up to 3 subs on one SMS-1 each with its own setting, then you combine them all for one curve. I use a Anti Mode 8033 with 4 subs and let it do its thing, then use the SMS-1 for a final tweak.

Bill

Yes, you could use multiple SMSs, one for each output.
But, there still would be no adjustement for delay/distance in the SMS.

They are now cheap enough that you could pick up a couple of them for under $800.

The other inconvenience is that you would need to use one to EQ them seperately, then use one to EQ them together, then seperate them again.

Any updates they do to the processing within their subwoofers are not likely to address the needs discussed here, discrete processing individual subs in for modern multisub systems, etc.


Unfortunately, the Audyssey/SVS box is also useless for a modern multisub system, as it only EQ's two subwoofers, and does so in a decidedly suboptimal manner (making them both equal instead of setting one as the primary and using others to fill in the response from there).

The only subwoofer EQ box that, out of the box, is really useful right now is the the JBL BassQ. The SMS-1 works well too, if the individual subs have some phase/FR/level adjustments.


Is that new firmware? If so, awesome! Go Velodyne!

Where can I get it, and is it possible to load it onto an SMS-1 from a Mac?

My SMS-1 only has global adjustments, and any other adjustments must come either upstream or downstream of it?

What do you mean by "each with it's own setting"? Are you referring to the settings on the subs themselves, i.e., levels, phase, etc.? On the SMS-1, you can *connect* 3 subs, but you only get one, global EQ curve. You can't have any SMS-1 "settings" individually for each sub.

Craig

Damn good to know! I am about to receive two dual 15" subs (DIY) and I currently own the SMS-1. I will also use the BASSIS from Marchand (here) in conjuction with the SMS.

I was thinking of buying the Audyssey unit but from what I read here it is not going to do me any good.


My idea is to use the BASSIS first for each sub with the SMS-1 as a measuring device and then combine both subs on the SMS for fine tuning. Yet, I will also buy an Onkyo SC5507 and this is where it gets tricky.

Would a second SMS help at all?

If you're getting the Onkyo, I suggest you try Audyssey MultEQ XT plus the SMS-1 first before investing in the BASSIS unit. Scroll up to post #92 to see what I was able to accomplish with that combination.

The biggest problem when trying to setup dual subs is to set them to "arrive" at the listening position in-phase and at the same level. If you can place them so they are equidistant to the LP, this will help. If you can't, you'll need some capability to delay one relative to the other and to level-match them. Neither the SMS-1 nor the Marchand unit can do that. However, Audyssey MultEQ XT in your receiver CAN do that, by setting different distances for each subwoofer and by adjusting each sub's level independently.

You can then use the SMS-1's Phase control to set the phase of the combined output for the best response with the speakers. Frankly, I think you can easily get very flat response with the combo of Audyssey MultEQ XT and an SMS-1, and still have the ability to adjust your bass to "taste". I really doubt you'll need the BASSIS unit.

Craig