My review of the Velodyne DEQ-8r is most relevant to its augmentation of the Martin Logan Electromotion ESL hybrid electrostatic loudspeaker.
The Martin Logan Electromotion ESL hybrid electrostatic loudspeaker is a great, mainly because it is the first Martin Logan electrostatic speaker at a price most can afford. The speaker is a real surprise, as it has the electrostatic quality of the more expensive models. The integrated 8” woofer is quite decent, although it takes awhile of play to bring out its sound potential. At this point, it is the integrated woofer, which does most of the lower frequency. Most of the lower frequencies should be reproduced by the internal ML 8” woofer. With the added Velodyne, It is not like using the Martin Logan as a satellite speaker where the bass is delivered by the subwoofer, it is only an effort to keep the roll-off at a bit lower point, thus providing a fuller bass, by adding a second woofer, which is made for lower frequencies, as we see in some high-end speaker designs.
The Electromotion ESL has a electrostatic panel of 129 square inches; with a sensitivity of 91db into 6 ohms. The Aerius has 93 square inches and a sensitivity of 89db into 4 ohms.
The more expensive Theos has the same electrostatic panel, but with a better made woofer and comes in different wood type configurations, this it has more style, it has a better woofer and is able to be driven by a separate power amplifier making it more adjustable, when you have an adjustable amplifier gain control. I will agree this speaker has better tonal integrity, but not by much, and looks prettier.
Enter the Velodyne DEQ-8r; the subwoofer has the advantage, when used with the Martin Logan Electromotion ESL to augment the bass as only the more expensive Ethos can., which has the same electrostatic panel, yet has the advantage of a built in power amplifier and a passive radiator, and yes the sound of the ethos. Is hard to accomplish with a electrostatic panel Martin Logan at three times the cost.
With the Velodyne DEQ-8r, this becomes near possible, and with the added features, the adjustable remote, it offers a way to make adjustments while listening to music. From my own trials, i have found best results by setting the Velodyne DEQ-8r at 60hz, then setting the volume low, then bringing up the volume to a point where the sound is fuller, more bass extension, without having an obvious separate bass location.
You need two of these subwoofers, hook then up to a preamp RCA output, using for both the left channel input; you can use a ‘y” splitter, I do not think it is a necessity using a preamplifier. Set the subwoofer to jazz setting and the phase to 0, there is not any need to run the EQ, as the jazz setting has the lowest roll-off frequency, about 15hz. The Velodyne DEQ-8r powered subwoofer is rated at 32hz -3dB; the Martin Logan Ethos is rated at 34hz -3dB, in reality, about the same.
By carefully placing and tuning, the Velodyne DEQ-8r powered subwoofer, will give the Electromotion ESL the ability to capture the lower frequency, which is the week point in this Martin Logan speaker.
Remember, the internal woofer in the ESL needs time to break is and when it us fully broken in, the sound of frequencies below the crossover point at 500hz, will sound nearly seamless; this is the big surprise with the ESL, it has a very good crossover network. The speaker is rated as lowest bass, 42hz -3dB, yet as many have noted, the bass gets a but anaemic at lower frequency registers, and this is the main problem with this speaker, not the electrostatic panel. Keep in mind, the Martin Logan does very well at lower frequencies, all the Velodyne DEQ-8r should do is keep the very low frequency roll off at a lower frequency, not supplement the bass above the lowest registers. The ML woofer does a very good job at most, but the lowest frequencies.
By using the Velodyne deq-8r with this Martin Logan speaker will give you the bass and is more adjustable than the Ethos. While i am not saying this is better than the Ethos, I am saying it is much less expense and offers some bonus features, such as the remote control.
Both woofers are 8” and seem to work well together, I do not know how well the Velodyne DEQ-10r would work as well; however, I have two high-end 12” subwoofers and I was not able to eliminate the bass location well.
My best results was placing the subwoofers alongside the ML speakers, on the outside of each; it also works well on the inside, yet since bass is much less directive, in my room setting, I found each subwoofers placed alongside and outside, or closer to the wall, to be the best option.
My ML speakers are 10 feet apart and the two subwoofers are about three feet from my side walls; all seems what I would expect from the Martin Logan Ethos at a much lower price especially now that the Velodyne DEQ-8r is being discounted.