Milesandcoltrane writes:
>I've also heard many great things about the Linkwitz Pluto. And since its available as a DIY I could save some bucks (though I have no experience whatsoever, so its a bit daunting).
Apart from maximum output level (a 16cm mid-bass lacks the displacement for bass at realistic listening levels) the Plutos are about as good as you can do in a cone + dome 2-way and they work better at short listening distances than anything except a coaxial.
You want to join the Orion/Pluto users group and post to The Official Seeking PLUTO Auditions thread
http://orion.quicksytes.com/viewtopic.php?f=12&t=994
Your brain determines timbre by taking the direct sound and mixing in other sounds that it identifies reflections.
Conventional 2-way speakers don't sound natural because the mid-bass has narrowing dispersion towards the top of its range while the tweeter has uniform output in all directions (directed only by the front baffle) so there's more high frequency energy in the reflections off the ceiling, floor, and side-walls. Better designers compensate for this with a notch filter although the results are imperfect compared to speakers that avoid the problem through more uniform off-axis response.
Similar but less noticeable problems exist at lower frequencies where wave lengths get long compared to the speaker baffle dimensions and radiation moves from hemispherical to spherical. A foot wide speaker has lost half its on-axis energy by 376 Hz and a smaller 8" mini-monitor by 565 Hz. Some of the sound wrapping around bounces off the front wall and adds back incoherently; competent designers make a guess about that and cut the high frequency output to match the results.
You also have problems with dome tweeters illuminating the baffle edges which produce diffraction, internal resonances and reflections which come back through the thin cone, and panel resonances because affordable speakers aren't braced well enough to push them out of the mid-range pass-band.
Pluto avoids all that. Both mid-bass and mid-tweeter are essentially omnidirectional around their 1 KHz cross-over point so the reflections match the direct sound. The tweeter and its baffle are about the same size so its directivity limits baffle diffraction as the baffle moves it towards half-space operation. The Pluto enclosures are damped transmission lines, with the mid-bass absorbing 99% (40dB return loss) of the energy coming off the back of its driver. A cylinder has no bending stress on it like a flat panel, so the enclosures are relatively inert.
The down-sides are that Pluto looks like the plumbing parts its made out of. Maximum SPL is limited by the small mid-bass; although to get around that you need to give up on polar response (making a speaker sound less natural) or increase your budget to accommodate a 3-way (Pluto+).
(I own a pair of Pluto+ in my bedroom system).
>I've also heard many great things about the Linkwitz Pluto. And since its available as a DIY I could save some bucks (though I have no experience whatsoever, so its a bit daunting).
Apart from maximum output level (a 16cm mid-bass lacks the displacement for bass at realistic listening levels) the Plutos are about as good as you can do in a cone + dome 2-way and they work better at short listening distances than anything except a coaxial.
You want to join the Orion/Pluto users group and post to The Official Seeking PLUTO Auditions thread
http://orion.quicksytes.com/viewtopic.php?f=12&t=994
Your brain determines timbre by taking the direct sound and mixing in other sounds that it identifies reflections.
Conventional 2-way speakers don't sound natural because the mid-bass has narrowing dispersion towards the top of its range while the tweeter has uniform output in all directions (directed only by the front baffle) so there's more high frequency energy in the reflections off the ceiling, floor, and side-walls. Better designers compensate for this with a notch filter although the results are imperfect compared to speakers that avoid the problem through more uniform off-axis response.
Similar but less noticeable problems exist at lower frequencies where wave lengths get long compared to the speaker baffle dimensions and radiation moves from hemispherical to spherical. A foot wide speaker has lost half its on-axis energy by 376 Hz and a smaller 8" mini-monitor by 565 Hz. Some of the sound wrapping around bounces off the front wall and adds back incoherently; competent designers make a guess about that and cut the high frequency output to match the results.
You also have problems with dome tweeters illuminating the baffle edges which produce diffraction, internal resonances and reflections which come back through the thin cone, and panel resonances because affordable speakers aren't braced well enough to push them out of the mid-range pass-band.
Pluto avoids all that. Both mid-bass and mid-tweeter are essentially omnidirectional around their 1 KHz cross-over point so the reflections match the direct sound. The tweeter and its baffle are about the same size so its directivity limits baffle diffraction as the baffle moves it towards half-space operation. The Pluto enclosures are damped transmission lines, with the mid-bass absorbing 99% (40dB return loss) of the energy coming off the back of its driver. A cylinder has no bending stress on it like a flat panel, so the enclosures are relatively inert.
The down-sides are that Pluto looks like the plumbing parts its made out of. Maximum SPL is limited by the small mid-bass; although to get around that you need to give up on polar response (making a speaker sound less natural) or increase your budget to accommodate a 3-way (Pluto+).
(I own a pair of Pluto+ in my bedroom system).