BFD v SMS-1

**russ.will** · **07-17-06, 03:16 PM**

Obviously, the BFD has a large fan base round here, I was wondering what people may think the pros/cons versus the SMS-1.

Russell

**Sonnie** · **07-17-06, 07:49 PM**

I was able to see the SMS-1 in action for the first time at JimP's home... just a few weeks ago. I was impressed with the unit. Would I spend the extra money to own one? No. I can accomplish the end result with the BFD for much less money... I'll just have to do a little more work in making it happen.

The one fairly nice benefit to me that the SMS has over the BFD is the convenience factor. With the SMS you can easily pull up the on screen menu, hook your mic into the unit and run test tones over and over.... make adjustments with a remote... measure again and see it right on screen.

The biggest benefit the BFD has over the SMS is cost. The downside is you have to be willing to hook up your computer to it in order to see the measurements as conveniently as you would the SMS. Once you get it hooked up, it pretty much the same then if you are using REW.

The only other significant factors to me would be number of filters and amount of cut/boost these filters allow, along with two channels and more presets... all favoring the BFD. These may or may not be needed, depending on what your initial results are and how many subs you have. One other favor I see for the SMS would be cosmetic design... it's more appealing to me, but regardless of which one I owned, they would be hidden.

Another benefit for BFD owners who might need it is the BFD forum with some awesome specialized moderators to help out when needed with very quick response.

There are probably some other things I'm not remembering right now.

**russ.will** · **07-18-06, 05:05 AM**

Thanks Sonnie,

The reason I ask is, full utilisation of the BFD, with REW, will require me updating alot of my hardware and operating system, so there's a substantial cost involved. A 2 month old SMS-1 cropped up on Ebay and I bought it on a whim as I was slightly under the the influence, shall we say. I'm interested to hear comparrisons such as yours.

Cheers

Russell

**Sonnie** · **07-18-06, 09:44 AM**

Be sure to let us know how it works out for you.

**russ.will** · **07-18-06, 12:39 PM**

Will do. I've just plugged it in and already found that the Auto EQ is rubbish!

Russell

**Sonnie** · **07-18-06, 08:19 PM**

Well... even REW is not perfect in this area. It does pretty good but I usually find myself tweaking it.

**MACCA350** · **07-19-06, 03:30 AM**

Quote:

russ.will wrote:

Will do. I've just plugged it in and already found that the Auto EQ is rubbish!

Russell

The auto EQ will not change any parameters in the 'System Settings' page, all those adjustments should be done beforehand. Auto Eq is only at the original Frequencies and Q settings, it only adjusts the level and nothing else, is not very aggressive and most would only use it as a starting point.

cheers

**russ.will** · **07-19-06, 04:17 AM**

When I said I had only just plugged it in, I wasn't kidding! Now I'm well into the system settings, I can appreciate the power REW must give in being able to see the imediate impact of applied changes. I spent nearly 1/2 hour just messing with phase and polarity. I could only do this by ear before and I was way out. A number of problem dips have already been solved and I'm now onto playing with specific frequencies and the Q adjustment with immediate results.

Russell

**nobbie** · **07-19-06, 05:01 PM**

Russell, I am thinking the same as you. Might I ask what you paid for your used SMS-1? Thanks and keep us posted on how things turn out!

**russ.will** · **07-19-06, 06:19 PM**

£400 GBP against the retail of £550 GBP. They don't come up very often over here and when they do, after the initial new v second hand drop, they seem to hold their price well. But so did my BFD.

I'll keep you posted on the results with graphs to demonstrate of course.

Russell

**russ.will** · **08-06-06, 05:58 PM**

Well, I'm now well into using the SMS-1 and have found the following:

It's not cheap.

It actually looks like it belongs in your rack.

The auto EQ is rubbish. Don't buy it if you're looking for a quick fix. It ain't!

It's very easy to use. Virtually no learning curve if you've used a BFD as a comparrison.

Everything is done from a remote control. Fantastic. The hotest July in Britain for years has not been spoiled by running up and down the room. Remember, no REW, it's was manual input only for me. Whadaya Yanks mean 95deg ain't hot! I've got real Scottish blood in me y'know. I was born in the rain.

It's not cheap.

Lack of messing about. As you also run a stereo connection into a spare input on your amp FROM the SMS-1, through which your sub is connected, you are a mere press of a button from running sweeps.

The cut and boost is more limited. As my main room problems are massive peaks, stacking filters solves this. Just like a BFD, it doesn't prevent you from wandering into the dangerous area of stacking boosts, so beware! Over here, it's not unusual to have a staircase running off the main room, which can cause big suckouts. There are some things you can't boost your way out of. This, fortunately, doesn't apply to me.

The easy way in which phase can be adjusted 360deg, is fantastic. I didn't have REW or the hardware to run it and so had settled on about 90deg of phase. The real time onscreen graphics bore this out, but 270deg worked even better. I'd never have known.

It's not cheap.

Audissey MultEQ added about 30cm (1ft) to the sub distance with the BFD. It adds 87cm (just under 3ft) with the SMS-1 in place. Make of that what you will with regards to processing delays.

Eight filters are only just enough. REW users may use extra filters to target very small peaks with a narrow Q. With the SMS-1 you're not left with many to play with, so you have to pick and choose.

House curves at the press of a button. You know, I'd never been a fan of subs when playing music. I justified this in all sorts of ways, signal purity etc, until I had the BFD. Once I had a flat(ish) response, I played and was surprised by what I heard. Problem was, I like my movies and the house curve I ended up with for movies, was too aggresive for my musical tastes. A smooth +6dB peak at 35 Hz for music suited me, but I liked a +12db boost centered on 20 Hz (my subs tuning frequency) for movies. Now whilst this is obviously possible with the BFD/REW by storing them on different presets, for me it took a lot of work (No REW). Once tuned to flat on the SMS-1 global setting, I realised I was never going to listen at 'flat' so I filtered in a +6dB lift to 20 Hz. Using the presets, I added a profile for movies at +6dB @20Hz (12dB total) and plus 2dB @ 35Hz (actually gives me more like +4dB which I like) for music. This leaves 3 presets I can use for specific films or occasions when I need to rattle the teeth out of a visiting noob.

It's not cheap.

The mic, which incidentally, weighs a tonne (metric, not imperial

) has lead me to a problem and this applies to all BFD/SMS-1 owners. Where you position it makes a really large difference. I started with it on a tripod (like I had with the Radioshack SPL meter) roughly where I considered the middle of my head to be. One day I noticed that surprisingly large variations appeared as I moved around the room. It got me to experimenting. I tried positioning the mic just above my head and just infront of my face. I also tried it positioned next to either ear and got as much as 6dB difference at frequencies well within the subs range. Now that's the sort of difference we're trying to tune out, but how do you tune for both sides of your head? As no sound arrives in the middle of my head (the usual position giving an average) where exactly should it be positioned? FWIW, I now postion the mic roughly where my head would be, but with me slouching in the chair just beneath it so at least my mass is in approximately the position it would be during a film. Just interested if anybody has some thoughts on this one.

I'll post some pre/post graphs soon, but since the arrival of the SMS-1, I can't remember where my test tones CD is so I'll do it as soon as I download some more.

Did I say it's not cheap?

Russell

**Sonnie** · **08-06-06, 11:22 PM**

Great comparison Russell... thanks!

One thing for sure... two things for certain... it ain't cheap!

**cyberbri** · **08-07-06, 05:15 PM**

Quote:

The mic, which incidentally, weighs a tonne (metric, not imperial ) has lead me to a problem and this applies to all BFD/SMS-1 owners. Where you position it makes a really large difference. I started with it on a tripod (like I had with the Radioshack SPL meter) roughly where I considered the middle of my head to be. One day I noticed that surprisingly large variations appeared as I moved around the room. It got me to experimenting. I tried positioning the mic just above my head and just infront of my face. I also tried it positioned next to either ear and got as much as 6dB difference at frequencies well within the subs range. Now that's the sort of difference we're trying to tune out, but how do you tune for both sides of your head? As no sound arrives in the middle of my head (the usual position giving an average) where exactly should it be positioned? FWIW, I now postion the mic roughly where my head would be, but with me slouching in the chair just beneath it so at least my mass is in approximately the position it would be during a film. Just interested if anybody has some thoughts on this one.

That's where room treatments - bass traps in the corners - come in.
I added room treatments first, which took away the boomy resonance and really tightened up the sound of the bass, and it toned down some of the big jumps in fr. There's also less variation in level across my couch, although it's still there. And now my BFD is arriving today, and I just need to get some RCA-to-1/4" adapters tonight at Radio Shack. Actually my sub's response is quite flat, after tweaking a lot, and just Saturday night discovered (test tones using HTPC + meter and XLS graph) that instead of running with no sub xo and phase at 180, I get MUCH smoother response by enabling the sub's crossover (90Hz) and switching to 0deg phase.

**oliverlim** · **08-22-06, 05:35 AM**

Quote:

cyberbri wrote:

That's where room treatments - bass traps in the corners - come in.
I added room treatments first, which took away the boomy resonance and really tightened up the sound of the bass, and it toned down some of the big jumps in fr. There's also less variation in level across my couch, although it's still there. And now my BFD is arriving today, and I just need to get some RCA-to-1/4" adapters tonight at Radio Shack. Actually my sub's response is quite flat, after tweaking a lot, and just Saturday night discovered (test tones using HTPC + meter and XLS graph) that instead of running with no sub xo and phase at 180, I get MUCH smoother response by enabling the sub's crossover (90Hz) and switching to 0deg phase.

I agree completely on this. I asked this question before as my room was not very treated 3 months ago. I get very different result even within 2 inchs of my head position much less a variation of totally different looking slope from the left side of my couch to the right and middle. The difference was in the region of 10-15db.

I have since added in about 8 boxes of fibreglass in my false ceiling and behind my drywalls. Each box consist of about 2feet x 4feet by 2" 4PCF of fibreglass (Thats why I dissappeared for a while from this forum

) And guess what. In my listening position, which used to have a 18db peak and dip between 20hz to 80hz without EQ now only has a 8db variation. So I went from +-9db to +-4db. and I even ran mt sub without a single EQ for a month other then adjusting phase as it was that flat and enjoyed it. If I flatten the main peak at 40hz by about 4db, I end up with +-2db across the 20-80hz region. Just one EQ!

Another interesting thing was that I can move the sub 2-4 inches left or right of my head position and there is almost no change in the FR. In fact from the left and right of my couch, the slope looks almost exactly the same with some minor variation of the volumn level. So All 3 sitting on the couch will basically hear almost the same thing. Only if I move the mic more then 4inches above or below my head positoin or front or back will it start to change. The Front or back will change more. So I really recommend tat some investment is done on room treatment esp bass traps which can be really cheap if you get OC type fibreglass and stuff them in the corners of your room.

Oliver

**russ.will** · **09-09-06, 04:34 PM**

Just realised that I said I'd post a graph of some recent (ish) results. This is the default flat setting with non of the preset curves applied. I'm particularly pleased with the smoothness from 40Hz past the crossover at 80Hz. I don't know where the dip at 24Hz comes from, but it's there before any filters are applied and I'm not going to try boosting it down at that frequency. I've since turned of the high pass filter which gives a more extension below 20Hz at the expense of a bit more sensitivity with the volume control.

Russell

**cyberbri** · **09-10-06, 12:19 AM**

Wait, if you're crossing it over at 80Hz, why are you boosting 100Hz, especially by that much?

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