Report for Discussion:
Two LFM-1 EX Subs with Velodyne SMS-1

I was hoping to have seen more discussion in the Saloon of this arrangement before I moved forward with my purchase from Outlaw. The Outlaws themselves, especially Scott, were very helpful in answering questions regarding the overall acoustic issues, system configurations, and potential benefits. I hope this report, and subsequent discussion in the Saloon will contribute to Gunslingers and Desperados alike.


Multiple Subs (Sources & General Issues):

The Saloon has produced many well reasoned posts concerning multiple sub arrangements, including mono vs. stereo, and separate subs for the LFE (0.1) channel. Thanks to all that have made this effort.

A very good research paper entitled, “Subwoofers: Optimum Number and Locations”, by Todd Welti, Research Acoustician with Harman International compares detailed computer simulation modeling techniques and actual room measurements for evaluation. It can be found here: >> http://www.harman.com/wp/pdf/multsubs.pdf << Synopsis: The study employs subs in mono configuration only, and the general conclusions of the paper are that multiple subs can significantly improve sound quality due to the modes common to domestic sized rooms. Computer simulations were run for 1-5000 subs in a 20’W x 24’D x 9’H listening room. A more practical analysis comparing computer and real room measurements for up to 18 subs was then conducted, with the conclusion that the benefit of using more than 4 subs was negligible. Also, the paper indicated that an even number of subs (2,4, or 6) produced a more even soundfield than an odd number (1, 3 or 5) when placed in a symmetrical arrangement. The paper concluded that “four subwoofers are enough to get the best results of any configuration tried. Two subwoofers is very nearly as good and has very good low frequency support as well”.

And last, but not least, Mickey Hart (drummer with the Grateful Dead) has contributed many interviews and work on the topics of stereo and multi-channel recording, studio remastering, bass management, and he is actively involved with the ‘Library of Congress Sound Recording Archive Project.’ His commentary is very entertaining too, as influenced by touring with the GD for 30 years, but I believe his studio work is an invaluable complement to computer and real room modeling analysis. Synopsis: Mickey Hart believes that the recording and mixing of low frequency material is a very critical and unique engineering issue. Both phase alignment and localization of low frequency material present much different problems than higher frequency material. This is why percussion and bass instruments use microphones directly at the source. They are recorded on separate tracks and often mixed to one channel, or as a mono signal to multiple channels to create location information without phase cancellation. In 5.1 channel mixing he has employed a lot of strategies, which include the splitting of individual instrument tracks between the LFE (0.1) channel including the fundamental, with overtones and higher frequency sounds produced to the surround channel(s) that locate the instrument in space. The design and placement of microphones for drum kits is both an art and science by itself. His DVD Audio re-mastered recordings of “Workingman’s Dead” and “American Beauty” (by the GD) put the listener in the middle of the band. This is much more of an art form than science to him.


My System Solution using Two LFM-1 EX Subs with Velodyne SMS-1:

Stereo Subs (before): For the past two years, my system consisted two 15" Def Tech subs, which were paired (with speaker level inputs) with the Right and Left front speakers (B&W N803’s with Outlaw 990 set to Large), resulting in a full range stereo mode configuration. The “LFE Only” signal was sent to third Velodyne sub. I was very pleased with the balance and tonal quality for HT, and especially for high quality stereo and 5.1 channel recordings. While I have been using stereo parametric equalizers for the main L/R channels, I have been unable to attain the same control of frequencies under 60 Hz compared to the new Velodyne Subwoofer Management System (SMS).

Dual Mono Subs (after): Three weeks ago I made the plunge for 2 LFM-1 EX’s and the SMS-1 Parametric Equalizer. The SMS-1 does not lend itself to a stereo sub set-up, and the crossover in the 990 only provides a summed mono signal sub output. To achieve true stereo subwoofer output would require a separate stereo crossover between the 990 Pre-Processor line-level outputs (at large, full range signal) and two SMS-1’s. (Yes, you can use speaker level connections if you dare) In any event, it would be very complicated. At this time, I cannot justify the effort and expense of achieving a true stereo sub configuration, and believe that the benefits of the SMS-1 to be significantly more important. After my research, I am not convinced that stereo subwoofers are of any real benefit below 60-80Hz if the subs are located to preserve the time alignment (phase) at the primary listening area.

Analysis: The SMS-1 is both a powerful analysis tool, and room/speaker correction device. Using the crossover network of the 990 (mains set to Small with 60Hz XO), the SMS-1 is easy to configure and set up. It was possible to compare the performance of one versus two subs easily, with the test microphone placed at various positions in the room. I found that two subs were significantly better for three reasons;
1) Much larger sweet spot,
2) More consistent sound level throughout the frequency range of the subs, and
3) deeper base extension.
One LFM-1 EX had a -2dB point of 17 Hz (one port plugged), whereas two subs were solid down to 15 Hz, which was the limit of the test trace. The controls and frequency response measurements are displayed through one of the 990’s audio/video source inputs.

Other Observations: My LFE channel is now also routed through both subs, so I no longer have a separate third sub dedicated to the LFE channel. I have not found any compression or other adverse affects in combining the LFE signal with the crossover signals from multi-channel recordings. As mentioned by others, I believe it is a good idea to place the subs close to the main L/R speakers or at least at a similar distance to the main listening position to preserve phase alignment of these long sound waves (a 40Hz wave is approx 25 feet long).

Testimonial...
In A/B testing, comparing the Def Tech subs vs. the Outlaw LFM-1 EX’s, there was an astonishing improvement, even before dialing in the EQ. The tonal balance, smoothness, and power of these Outlaw beasts (coupled with the SMS-1), allow for music to be played at preposterous dB levels without sounding “loud”. Distortion is the enemy of volume, and Outlaws.
Thanks Outlaws.

great write up. thankyou!

Anyone have any thoughts about combining a LFM1 and LFM1 Plus in an environment with SMS-1. The reason I ask is that the two subs are similar but a little different, and I don't know if the difference is that significant.
TIA

Given how similar those two subs are, you should be OK. However, I would probably turn the LFM1+ about 3db higher than the LFM-1 so they would both max out at about the same volume (or your LFM-1 could be holding the system back). Also, I would not use any equalization on the sub 20hz frequencies, as you would be demanding excessive frequencies which the LFM1+ can produce but the LFM-1 cannot (could also leave you with a struggling LFM-1).

I would say give it a try.

Here is a question. I have a Fathom 113 subwoofer and I am thinking about getting another subwoofer. I am very happy with this product and my intentions were to buy two of them but money was the issue. The SVS PC Ultra was reccomended to balance out the sub response in my room. I was more interested in the Outlaw LFM1 Plus.
It was not the price issue since the Ultra is twice as much that I was interested in the Outlaw but the quality of the product. I have been to at least ten Home Theater shows in the past and Outlaw's subwoofers always sounded great.
Can anyone give some advice without being one sided.
I want to make a good choice the first time and not be disappointed. Some responsing have said to buy another Fathom.

Well, the current ultimate bang-for-buck solution seems to be AV123s new MFW-15. AV123, Epik Subwoofers, and Elemental Designs seem to have taken the direct sales crown for value sub woofers.

care of craigsub on avsforum...
http://www.avsforum.com/avs-vb/showthread.php?t=768150

Elemental Designs A7-900 ($2200 ID/SI): 116 points (63-53)
Epik Conquest ($1599 ID): 112 points (60-52)
SVS PB13-Ultra ($1499 ID): 109 points (57-52)
Epik Castle ($999 ID): 109 points (59-50)
AV123 MFW-15 Duals: 109 points (56-53) (note, duals were tested as duals are offered as a package)
Creative Sounds Dual SDX-15 driver + Behringer EP-2500 Amp + Behringer DEQ2496 ($1630 ID): 105 points (57-48)
JL Audio Fathom 113 ($3500 BM): 103 points (53-50)
AV123 MFW-15 ($599 ID): 103 points (53-50)
Def Tech Trinity ($3000 BM): 102 points (54-48)
Velodyne DD-18 ($5000 BM): 100 points (50-50)
ACI Maestro ($2400 ID): 97 points (47-50)
eD A5-350 ($715 ID/SI): 96 points (50-46)
JL Audio Fathom 112 ($2600 BM): 95 points (45-50)
Hsu VTF-3 HO + Turbo ($999 ID): 94 points (47-47)
Hsu VTF-3 HO w/o Turbo ($899 ID): 92 points (45-47)
Hsu VTF-3 Mark III + Turbo ($799 ID): 92 points (45-47)
Epik Valor ($549 ID): 91 points (44-47)
Hsu VTF-3 Mark III w/o Turbo ($699 ID): 91 points (45-46)
SVS PB12-Ultra: 90 points (47-43)
Axiom EP-500 ($1230 ID/SI): 90 points (43-47)
Hsu VTF-2 Mark III + Turbo ($599 ID): 88 points (42-46)
SVS PB12-Plus/2 ($1299 ID): 87 points (47-40)
SVS PB12-NSD ($599 ID): 86 points (43-43)
Hsu VTF-2 Mark III w/o Turbo ($499 ID): 86 points (40-46)


It is a tough call. I *love* my LFM-1 EX, but it is hard to ignore shiny new toys!

Thanks.
After doing some reading about the reviews of subwoofers I think that I will wait and perhaps invest in another Fathom 113.

A lot of bucks but A LOT OF BANG!!!

True, but you could sell the F113 and get almost 4 MFW-15s! (TONS OF BANG!).

All depends on your aesthetic needs.

Am I the only one that noticed that none of the Outlaw subs were reviewed on the "bang-for-buck" list above! When I was getting ready to upgrade my sub I auditioned several different subs before ordering my LFM-1 EX and the SMS-1. Nothing and I mean nothing came close in the "bang-for-buck" category. I tried a couple of different Velodyne's, Rel's, and B&W's all of which performed well but I thought were very high priced. I was upgrading from a Boston Acoustic sub so I thought I would give them a try. The BA's were of course much more reasonably priced but I just didn't feel the love when I listened to them.

So I decided to order the LFM-1 Plus for a 30 day trail. However, at the time Outlaw had a deal going where I could get the LFM-1 EX and the SMS-1 at a very good price so I went that route. Well, it has been in my living room ever since! I have been extremely impressed with the unit. The only thing that I have heard better (and not based on "bang-for-buck", but based on what sounds the best) has been when I got the Auralex GRAMMA to put the sub on top of it.

Based on the subs that I auditioned, I would have had to spent 3 or 4 times as much to get comparable performance.

BTW, for those interested the reason I got the GRAMMA was due to my sub being located on a tile floor that is not smooth. Therefore the sub could not be positioned with entirely equal weight on all four feet which caused an occasional rattle as well as the sub tended to "walk" across the floor. You can refer to my post on this topic here. If you look near the bottom of that thread you will see my review of the GRAMMA. I can highly recommend that simple and inexpensive unit as a way to improve any sub that you are using.

Like speakers, Subs are clearly a very personal choice. I noticed that the Stereophile Review of the Fathom 113's was for two subs, run in stereo mode, with some tweaking and analysis aided by the reviewer's own Velodyne DD-18 (which has the SMS-1 built-in). The article was effusive and clear about the significant quality upgrade using two subs instead of one ... and claiming it to be the best base enhancement ever made to his system.

My purpose for contributing my review of two LFM-1 EX's with the SMS-1 was exactly because I did not find a discussion of the sonic and value advantages of using two or more Outlaw subs. I purchased during the Sonic Boom Sale, and got everything to my door for under $1,900 new. (OK... another $200 in Interconnects...)

I can also confirm that the SMS-1 allowed me to make a quantitative evaluation of some real benefits to having the extra sub. More importantly, however, my ultimate opinion of this arrangement is based on a A/B comparison of how I felt in the center position of the couch, listening to a lot of two channel music.

For what it is worth, I was blown away by a sense of spacial envelopment and clarity that leaves me thinking the same thoughts as what I read in the Stereophile review (about the stereo Fathom 113's) for less than 1/3 of the price. It's been almost a month now, and I am still blown away...

While I am sure that the JL Audio subs (and similar) are worth the price, I would hope that some audio-heads would consider using two (or more) Outlaw subs as a real alternative to some more expensive equipment. I know that the Hsu subs are very similar, and also present great value, but I believe in supporting this Outlaw Audio venture when I can. I honestly do not think I could have made a better choice than Outlaw for my needs, and believe there are a lot of people who, like me, are a bit in disbelief when such a product is available for so little money. I still shake my head, when my subs are off... :rolleyes: