ThresholdSpectralLover
23-04-2010, 06:29
Here are my DIY speakers that I'm listening to these days. - They may look BAD, (Yikes! LOL) but they are the best I've ever had. 1st the technical side: The top boxes are +- 2.5 DB from about 300HZ up. The problem that I have with testing in my place is that with my projector screen, and smaller room, it isn't enough room to test the individual speakers down to say 200 hz. This results in me not compensating for the diffraction loss, so without the bottom box the top satellites start to drop off the lower mid/upper bass to fast, and they sound a bit shrill. With the Behringer Ultradrive crossover that I use and with the bottom boxes, I can compensate for the diffraction perfectly, and I'm THRILLED with the way that they sound now.
The art side: The top boxes are braced like rocks! I used about 40 Cu inches (650 Cu CM) of red oak inside. The braces come off a center top to bottom piece, and they touch the walls at two points on each side inside. The bolts are torque tuned to two different settings. When you knock on the box it is really like knocking on a solid block of MDF. They are covered with linoleum tile, which kills off the last bit of resonance. The drivers in the top box are TRI-WIRED with the crossovers as close to the amp as possible. This is something that I would not do again. I don't think that I hear the difference as much as I thought, and having the crossover 1 foot away from the amp, makes dealing with it a real pain in the a$$. LOL
One thing is completely unorthodox: The top tweeter breaks the rules of conventional design theory which states that a supertweeter should be as close as possible to the lower tweeter. I did this as kind of a band aid. After testing the MTM array, the center tweeter has a rough response above about 6K. The solution? Add a supertweeter on top, and cross it over! LOL The good news is that this seems to give the top speakers, a MUCH bigger sound. They sound almost as large as a 1 meter high ribbon. The combo of the Dynaudio D-28II and the D-21a.f. have a superb sounding treble, with a TON of dynamic range.
The bottom boxes are totally reinforced Fisher XP-7 boxes. By the time that I was done with them, I realized it would have been easier to just build NEW boxes. They have adjustable, aperiodic tuning, which you can see in some of the pics. I have them sitting on small patio bricks, to keep the bass tighter, so that the cabinet doesn't resonate in to the floor.
They are driven by a Threshold S-300 series II E-mod on the top, and a Threshold S-300 II on the bottom. The amps are class-A up to about 25 watts per channel. I guess the setup is good for a total of about 50 watts class-A per side. They are 4 ohms, so I'm looking at 600 watts per channel. (I hardly ever go over 5-10) My subs, and the third Threshold are not hooked back up yet. Subjectively, IMO, this combination has extremely clear definition. The bass is extremely tight and, fast. I was playing the Bobby Colomby drum solo off of, "Blood Sweat & Tears II." L.P. I wanted to push it until it said uncle! It sounded like he was in the room, and suddenly I heard a WAP which was the voice coils bottoming out on the back plate. They are the older Etons, and they don't have the extended rear bump room like the newer versions have. When I hook up the subs, and get the low bass out of them, I doubt that it will happen again. With the, "Hexacone" technology, they have been described as sounding like electrostatics.
Anyway, I should call them the, Ugly 1-a's! LOL They thrill me though. ETA: They don't sit lopsided like they appear to. LOL That was me shooting them with my camera turned 90 degrees.
The art side: The top boxes are braced like rocks! I used about 40 Cu inches (650 Cu CM) of red oak inside. The braces come off a center top to bottom piece, and they touch the walls at two points on each side inside. The bolts are torque tuned to two different settings. When you knock on the box it is really like knocking on a solid block of MDF. They are covered with linoleum tile, which kills off the last bit of resonance. The drivers in the top box are TRI-WIRED with the crossovers as close to the amp as possible. This is something that I would not do again. I don't think that I hear the difference as much as I thought, and having the crossover 1 foot away from the amp, makes dealing with it a real pain in the a$$. LOL
One thing is completely unorthodox: The top tweeter breaks the rules of conventional design theory which states that a supertweeter should be as close as possible to the lower tweeter. I did this as kind of a band aid. After testing the MTM array, the center tweeter has a rough response above about 6K. The solution? Add a supertweeter on top, and cross it over! LOL The good news is that this seems to give the top speakers, a MUCH bigger sound. They sound almost as large as a 1 meter high ribbon. The combo of the Dynaudio D-28II and the D-21a.f. have a superb sounding treble, with a TON of dynamic range.
The bottom boxes are totally reinforced Fisher XP-7 boxes. By the time that I was done with them, I realized it would have been easier to just build NEW boxes. They have adjustable, aperiodic tuning, which you can see in some of the pics. I have them sitting on small patio bricks, to keep the bass tighter, so that the cabinet doesn't resonate in to the floor.
They are driven by a Threshold S-300 series II E-mod on the top, and a Threshold S-300 II on the bottom. The amps are class-A up to about 25 watts per channel. I guess the setup is good for a total of about 50 watts class-A per side. They are 4 ohms, so I'm looking at 600 watts per channel. (I hardly ever go over 5-10) My subs, and the third Threshold are not hooked back up yet. Subjectively, IMO, this combination has extremely clear definition. The bass is extremely tight and, fast. I was playing the Bobby Colomby drum solo off of, "Blood Sweat & Tears II." L.P. I wanted to push it until it said uncle! It sounded like he was in the room, and suddenly I heard a WAP which was the voice coils bottoming out on the back plate. They are the older Etons, and they don't have the extended rear bump room like the newer versions have. When I hook up the subs, and get the low bass out of them, I doubt that it will happen again. With the, "Hexacone" technology, they have been described as sounding like electrostatics.
Anyway, I should call them the, Ugly 1-a's! LOL They thrill me though. ETA: They don't sit lopsided like they appear to. LOL That was me shooting them with my camera turned 90 degrees.