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Review 2 of 2
Price Paid:
$599.00
from Direct from Outlaw Summary:
Two LFM-1 EX Subs with Velodyne SMS-1
I was hoping to have seen more discussion in the Outlaw Saloon of this arrangement before I moved forward with my purchase from Outlaw. The Outlaws themselves were very helpful in answering questions regarding the overall acoustic issues, system configurations, and potential benefits.
Multiple Subs (Sources & General Issues):
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...
Strengths:
Price, Build Quality and seamless integration with Stereo and Surround Systems.
Two Subs for less cost than one of the elite brands is just TOO good to be true, and with balance and musicality that are hard to match at any price... a no brainer. Weaknesses:
Size and Weight may be too much for smaller rooms, if that is a weakness... Similar Products Used:
Velodyne, B&W, REL, Definitive Technologies
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5 of 5
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