Anyone who has a home theater needs a subwoofer. If you want your viewing room to look like Pearl Harbor after the Japanese attack by the end of the movie, there’s no getting around that statement. More moderate people, a group to which I feel I belong, can be satisfied with a smaller subwoofer, where their records remain undamaged on the shelf and the small cracks in the walls come from mining work rather than speaker volume. But it’s much harder to use a subwoofer when I want to listen to music. Things that need to be exaggerated in a movie are completely out of place here, where the extra bass should only be noticeable when it’s turned off. So I always have to crawl behind the sub box to adjust the volume and separation frequency to the new situation. That alone kept me from using the low bass slinger for years, but I saw the light when the WAM 300 DSP turned up. Digital presets are the magic formula, providing the perfect combination of volume and bass power for the appropriate task, at the touch of a button from the comfort of your couch. My conversion started with the SB 29 CB and BR sub, and then a bass with a wide seal and a gigantic lift showed me that it could be used in more than one situation. Seas called it L 26 Roy, which of course led to its assembly-kit name: Elroy.
The design series bass was introduced a few years ago in the September 09 issue. My Clio data still differs from the data on the Seas side, compared to the Klippel and the other levels, but that doesn’t reduce its usability or the quality of the monstrous chassis. Its impressive 10 kg of live weight comes mostly from the thick magnet, with its protective rubber coating, and from the extremely sturdy basket. The extremely stiff aluminum membrane, which only shows resonances above 3 kHz, is much lighter than the sludge valves often found in home theaters. With a 56-mm thickness and fiberglass brackets, the voice coil is double-layered and wrapped up to 38 mm. Its 10-mm yoke thickness keeps the same number of coils up to the lift of 28 mm in the air space. Naturally, it has copper on the pole core, ventilation in the membrane and the lower pole plate, and large openings in the basket below the high-set spider. More details can be seen in the photos, which you can enlarge by clicking on them.
The L 26 Roy is versatile thanks to its parameters, which make it useful both closed and reflex-tuned, in 17 as well as 80-liter sizes. Of course it was tempting to try out the smallest model, but I didn’t want to use up the very last reserves of the DSP module just to get down lower. A size of roughly 45 liters seemed healthy to me, giving the chassis enough installation room and the cabinet the necessary durability. My simulation with LspCAD already showed enough depth in the closed version, with just a few lifts needed to help out in the right places. I skipped the construction photos, even though this time there were more than six boards to be glued on with joint adhesive. In order to prevent confusion during the self-building process, though, I animated the SketchUp drawing to make a small slide show.
The usual construction drawings and the SketchUp file are also still available.
As I was dissecting the little SketchUp pictures for the “film,” I heard some grumbling from my photo studio. The flash equipment and the camera were worried they were going to start collecting dust because I didn’t need them to do the documentation any more. I quickly convinced them otherwise by taking pictures of all the steps up to the chassis installation, and a sense of calm returned to my little studio.
I needed that calm when I quickly transformed the photo studio into my measurement room – it’s nice to have a versatile space. As with the SB 29 sub models, I compared the presets and their effects with one another.
Defeat, open on top:
Defeat separation at 80 Hz with 24 dB edge steepness:
Music with the same settings:
For the sake of clarity, I also layered the measurements in a single diagram. The colors are the same so that they can be clearly assigned to the equipment.
The most important button on the WAM 300 DSP remote control is labeled “User,” and it can be freely programmed using slide-controller software. I measured three different settings.
User 1, with a slight emphasis around 50 Hz for a pounding bass:
User 2, with a smoother sequence:
User 2, with more deep bass. The controllers stayed the same, but the edge steepness was increased to 36 dB. I also increased the volume by 4 dB.
Once again, here is the diagram with the three curves:
Now, it’s a little boring to listen to a subwoofer by itself. Without satellite speakers, nothing comes together. Elroy is designed to provide the necessary foundation for our compact-series Seas assembly kits. Here, the separation frequency and volume have to be set individually according to the size of the other speakers. Because they happened to be available, I set up two MS Micros as partners in the listening room and set the receiver to 80 Hz on my AVR. After ten minutes, the adjustments were finished even without taking any Clio measurements. First, the bass was connected in-phase at the last measured setting, then phase-shifted, which created a little more pressure. The shift to 45 degrees was then already in harmony. I adjusted the volume using the remote control, until the bass was only noticeable when I hit the mute button. For the first time, I was able to enjoy music in stereo with my Kinoamp, which I openly admit I had never loved. Freed from the burden of producing bass sounds all by itself, it finally stopped its uncontrollable grumbling. Even if I’m still not a huge fan of 2.1 after my listening session, if space were an issue I could get used to how Elroy and Micro presented the music. The easy switch to 5.1, where the bass doesn’t need to fit in as perfectly with the sound pattern, simplifies the complex problem of offering video with audio versus pure listening. While in the stereo department, the bass really only supplemented the deep frequencies, with film it was literally able to impressively move air through the room, thanks to its enormous lift capacity. If you’re looking for even more, you can also run two subwoofers with the WAM 300 DSP; for Elroy, they can be serially connected to stay on the safe side. But even parallel operations barely heated up the module to more than lukewarm temperatures as I drove my neighbors crazy looking for the source of the humming noise that could be heard through the whole building, from the basement to the attic, during a two-hour test run at 40 Hz and more than 20 volts with 2 ohms of output.
The last pictures once again prove that my title choice was appropriate. Elroy can be set on any side, depending on how much space you want to give it. The only exception is the front, but who would have a crazy idea like that?
|Chassis||Seas L 26 Roy||Wood list, 18-mm plywood|
|Sales||Intertechnik, Kerpen||58,0 x 44,0 (2x) front/ rear wall|
|Construction||Udo Wohlgemuth||58,0 x 21,0 (2x) sides|
|40,2 x 21,0 (2x) lid/floor Boden|
|Principle||Closed||10,0 x 21,0 (4x) reinforcement|
|Nominal impedance||4 Ohm||5,0 x 21,0 (4x) reinforcement|
|Insulation||4 bags of Sonofil|
|Terminal||T 105 MS/ AU|
|Aktiv amplifier modul||WAM 300 DSP|
|Assembly kit without wood||460 Euro||Wood cutting: 30 Euro|
Elroy is available from Intertechnik as part of a set with the WAM 300 DSP.
The WAM 300 DSP is also avialable seperate. Klick here.