Velodyne answers a question.

Other than price, the following are some items comparing the Velodyne HGS-12X with an outboard SMS-1 to a DD-12:


1. I believe the SMS-1 is built into the DD-12, but don't both versions perform the same using the same software?

2. The cabinets are about the same size

3. I can sell the HGS-12X and put the SMS-1 on my new sub

4. If an SMS-2 (or whatever) comes out that is a big improvement, I can buy it, while the DD-12 may not be upgradeable.

5. Using either the SMS-1 or the DD-12 is easy for equalization in the range of 0 Hz (in theory) to 80 Hz. But the usual problems of even a reasonably well designed room are from 0 Hz to 200 or so Hz where a graphic or parametric equalizer can cover the entire range.

6. I haven't checked, but my guess is that an HGS-12X/SMS-1 on the internet will be cheaper than the DD-12, which I believe is only available thru dealers.


So, what's the difference? Which is your preference and why? Do I want any HGS-12X/SMS-1 or DD-12? Maybe an HGS-12X with a Behringer Feedback Destroyer or similar would be the most flexible, albeit more effort.

Take Aim

You can get a single sub to "fill" your room. But, what Velodyne stated about using two subs to "produce a more even distribution of bass throughout the room" is valid. Ideally, I'd recommend 2 subs and the SMS-1. If budget is a concern then use 1 sub and the EQ, add the second sub later. EQ doesn't solve problems that 2 subs can, but is does help.


The SMS that is built into the DD series is the same with the added ability to adjust the accelerometer in the DD series. A small advantage for the DD series. Plus it is a slightly better sub than the HGS but not a lot better.


To add a second sub to the DD series you need to add another DD and use the RS-232 to daisy chain them together for the settings. You can't use the DD's built in EQ with other subs beside the DD series. With the SMS-1 you can use it with up to 3 of any subs you like.


The SMS-1 only works on the LFE channel. To EQ above the crossover you would need an EQ between your preamp and amps.


Hope this helps.


Bob

I know you're supposed to experiment within each HT and they're all designed differently, but where is the "usual and customary" placing of two subs in the HT? If on the same front wall, distance apart? I don't want to overemphasize the bass, just a smooth response at all frequencies.


In a 5.1/7.1 system, the bass is directed to the sub. So the easiest is to use an SMS-1 (or DD-12) to equalize the bass. The more difficult and time consuming would be a BFD-type equalizer and software on the LFE output of the receiver that connects to the sub.


If the room is tested with software (ETF, etc) and found requiring further equalization of the non-bass, then a PE or graphic equalizer can be added to equalize the other speakers.


If the majority of equalization problems occur in the bass area, an SMS-1 may solve most of the problems and do it easily.

Take Aim

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There are two ways to do it (well, I guess a lot more, actually). One is co-locating. Doing this, you put the subs less than 12" or so apart. This increases the total gain by 6dB over having one sub.


The other option of spreading them out is probably what you're looking for. As for placement, there has been some discussion recently of placing two subs on the midpoints of opposing walls. For instace in the middle of the front and back wall at the midpoint of the two sidewalls. This is not practical for many people, however, so you may find it easier to start with them in the two front corners.

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A single HGS-15 is good for up to 4,000 cubic feet.

Once you drop to the HGS-12, output at lower frequencies decreases.

Its a hard call to say whether the DD-15 or the HGS-15 w/SMS-1 would be preferred. Each has its advantages.

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Hi Jim,


If you are serious about eventually measuring your room response with ETF, then why don't you download the free demo and you'll be able to definitely answer these specific questions?


For example, as you know the SMS-1 or DD subwoofers only have filters from 20 Hz to 120 Hz. If you had uneven bass response above the subwoofer crossover, say between 120 hz and 250 hz, you would need an other equalizer, such as the BFD to adjust your main speakers.


If you measure your room response first you would know with certainty whether you need additional equalization beyond your subwoofers. In your small room it is highly likely that bass problems will be at higher bass frequencies than a larger room.


Larry

I have found, commonly, that problems in the 100 Hz and up range are less severe and can be more easily solved passively without too much expense or asthetic disruption than those in the lower bass regions. Also any anomylies created with EQ's in the upper ranges seems to be more subjectively apparent than those in the lower bass. And while differances in listening positions (and therefor sub placement) can be somewhat challenging and yield differant qualities in differant locations with regards to subs, these problems seem more difficult to reconcile at the higher frequencies with regards to EQing speakers with reagards to seating placement. Passive corrections though seem to work much better , imo, as they provide a much more consistant remedy throughout the room. Those who attempt to completely remove the room from the equation sometimes find that sounds not generated from the electronics (such as casual conversation and mechanical noises, outside road noise, etc) can detatch the recorded music more from the other real sounds in the room.


I'm sure I will be taken to task for these statements, so let me again state that these are subjective opiniuons of someone who has set-up MANY, MANY systems in treated and untreated rooms over the years. I have read and heard many objective opinions on why this isn't/shouldn't be the case, but experiance has lead me to these conclusions.

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Hi,


I don't take exception to your statements. Jim (takeaim) has installed soffit mounted bass traps, and hopefully they will help the overall bass response, but of course he won't know until he measures the room.


His seating locations and speakers are locked in concrete. He may have some latitude in the placement of subwoofer(s) across the front of his room, but I believe he plans to place them in an enclosure under his screen so he won't have much latitude getting them away from the front wall. When speaker and listener placement options are limited it is more likely that an approach that uses both passive treatments and equalization will be required.


Larry