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What's so hard about listening at tweeter level? George
Quote from: zybar on 3 Jul 2009, 04:35 pmWhat's so hard about listening at tweeter level? GeorgeHmm, you never do anything else while listening to your stereo? Anyway, sitting for hours can be difficult.
Jim, Dennis,If they sound not-so-good off the tweeter axis, -"For MTM's, if you're above or below that point, the arrival times of the two woofers will be different and they will start to cancel out in the midrange. Check out the last graph at the bottom of this link. http://murphyblaster.com/content.php?f=gem_mod.html "why don't you build the Songtowers like the one-off S2's?http://www.audiocircle.com/index.php?topic=65726.0
First, it is not that an MTM arrangement "sounds not so good." Joe D'Appolito made this arrangement famous and the design does offer increased sensitivity and lower distortion due to the fact that dual woofers are utilized.
Quote from: jsalk on 3 Jul 2009, 05:11 pmFirst, it is not that an MTM arrangement "sounds not so good." Joe D'Appolito made this arrangement famous and the design does offer increased sensitivity and lower distortion due to the fact that dual woofers are utilized.Well, I guess my wording was "not so good" as I guess I should have simply asked why he chose the MTM design over the TMM design given two identical speakers and cabinets and what were the advantages of each.
This is a complicated subject, and not everyone agrees on the advantages of an MTM. The original theory was to use 3rd order acoustic slopes in conjunction with symmetrically mounted woofers to provide a very focused forward sound with controlled vertical dispersion. Joe D'Appolito later gave up on the 3rd order slope requirement, and it's not clear how important the driver configuration is for vertical dispersion. But with your ear on the tweeter axis, you avoid any comb filtering between the woofers. In an MMT crossed above 1500 Hz (and virtually all are), the woofers will not be at equal distances to the ear (unless you listen between the woofers, which would be weird), and response irregularities are difficult to avoid, whether you're standing up or sitting down. When you stand up listening to an MTM, comb filtering will occur, wherever you ear is relative to the tweeter. But if the drivers are fairly close together, this will only be a serious issue if you stand very near the speakers (the alarming dip I posted a link to was made with the mic 1 meter away and considerably above the tweeter), At normal distances, standing and walking around the room will simply produce a slightly more recessed sound, and it might be quite subtle. I have ST's as my main speakers, and I'm not bothered when I stand up. But it's best sitting down.