Hey fellow DIYers……I’ve seen many of these builds here and elsewhere…..even read through a few of em only to get left in the dust of confusion as to the design principles and the ‘why’ of it all. Not to mimimalize the design or the efforts undertaken to build them in any way……just what makes it the advantage over the more classic and conventional solutions when considered for practical in home applications. Thanks!
That is a factor. In a home situation one can get a regular 1" compression tweeter to play well below 1k. There doesn't seem to be a benefit to making a MEH cover that same range when it isn't otherwise necessary.
One of the reasons the MEH was so beneficial to Danley was because it dealt with the issue of wind disturbing sound travelling longer distances across a stadium with conventional multi-way. Another is it helped with consistent coverage across that area. Additionally, they're easier to array that way. Then there's the portability they afford, not to mention the increased power handling of smaller bands.
One of the reasons the MEH was so beneficial to Danley was because it dealt with the issue of wind disturbing sound travelling longer distances across a stadium with conventional multi-way. Another is it helped with consistent coverage across that area. Additionally, they're easier to array that way. Then there's the portability they afford, not to mention the increased power handling of smaller bands.
It's elegantly simple really.....it's a way to get drivers centers-to-centers closer, and move more towards a hypothetical point source.
On a flat baffle, it's pretty much impossible to keep multi-way sections c2c's within 1/4 wavelength at crossover.
Here's a theoretical example of a ring array attempt at that, pulled from one of Danley's synergy patents
Now drape that flat baffle with all its drivers over the top of a pyramid, and the whole thing collapses, bringing all the drivers c2c's closer in the horizontal and vertical planes, when the pyramid is rotated to have the base face the listener.
Getter the driver sections closer is not an issue1 kHz and up. Like Allen said, that range is easily handled by a compression driver on a waveguide.
Even getting down another octave, is not too difficult with a single driver and horn.
But if you want 1/4 WL driver spacing all the way down, I don't know of another realistic way (other than line arrays whose problems lie on the top end of the spectrum)
So, like said at beginning....it's all about trying to get as close to a point source, over as much bandwidth as possible.
On a flat baffle, it's pretty much impossible to keep multi-way sections c2c's within 1/4 wavelength at crossover.
Here's a theoretical example of a ring array attempt at that, pulled from one of Danley's synergy patents
Now drape that flat baffle with all its drivers over the top of a pyramid, and the whole thing collapses, bringing all the drivers c2c's closer in the horizontal and vertical planes, when the pyramid is rotated to have the base face the listener.
Getter the driver sections closer is not an issue1 kHz and up. Like Allen said, that range is easily handled by a compression driver on a waveguide.
Even getting down another octave, is not too difficult with a single driver and horn.
But if you want 1/4 WL driver spacing all the way down, I don't know of another realistic way (other than line arrays whose problems lie on the top end of the spectrum)
So, like said at beginning....it's all about trying to get as close to a point source, over as much bandwidth as possible.
Aaaaagh….ok….so it’s the point source presentation but the directivity control is still dictated by the size of the horn. So if you required directivity down to 500hz, mounting the midbass drivers within an MEH doesn’t help unless te size of the horn is the typical unruly beast I could live without.
Mark described things pretty well.
Tom’s effort to (and succeed) in getting centre-to-centre within a quarterwave at the XO frequency, essentially making the drivers all essentially coincident (phase, time, acts as a single driver. One better than a coax which typically needs time delay to achieve time coherence.
Out of this research came the importance whole quarter wavelenght thing. Really goosed my adventures in WAWs.
Danley's Synergy was a truly new loudspeaker. One of only 2 i have seen (and the other while unique was not really groundbreaking). The first piblic discussions happened onthe old BassList.
dave
Tom’s effort to (and succeed) in getting centre-to-centre within a quarterwave at the XO frequency, essentially making the drivers all essentially coincident (phase, time, acts as a single driver. One better than a coax which typically needs time delay to achieve time coherence.
Out of this research came the importance whole quarter wavelenght thing. Really goosed my adventures in WAWs.
Danley's Synergy was a truly new loudspeaker. One of only 2 i have seen (and the other while unique was not really groundbreaking). The first piblic discussions happened onthe old BassList.
dave
They have a number of useful qualities, but my interest in MEHs is in their directivity within a home environment (in my case both for controlled off-axis response and in reducing early room reflections). This kind of thing can be done in a few ways, such as a cardioid configuration or using direct radiating drivers that are big enough to beam at a desired angle. But I believe that waveguides or horns are particularly well suited to directivity control.
There are a number of ways to impliment them - such as multiple horns, a horn/waveguide handing over to a big woofer (large enough to match directivity at the crossover), or a single horn shared by more than one driver (MEH). Most of these things end up being quite large, but the MEH appeals to me because they can be made full range within just the one horn (not needing multiple horns or a horn plus a separate bass driver). They can also provide a coherent point source almost from the word go, whereas many other arrangements involve more significant separation between their component drivers/sources.
But all speakers are a bundle of compromises; none are best and certainly none are perfect, all have flaws and difficulties, the different designs just make compromises in different places. What appeals to one person or situation may not be best in another; they may be appropriate to you (the OP) or they may not be.
There are a number of ways to impliment them - such as multiple horns, a horn/waveguide handing over to a big woofer (large enough to match directivity at the crossover), or a single horn shared by more than one driver (MEH). Most of these things end up being quite large, but the MEH appeals to me because they can be made full range within just the one horn (not needing multiple horns or a horn plus a separate bass driver). They can also provide a coherent point source almost from the word go, whereas many other arrangements involve more significant separation between their component drivers/sources.
But all speakers are a bundle of compromises; none are best and certainly none are perfect, all have flaws and difficulties, the different designs just make compromises in different places. What appeals to one person or situation may not be best in another; they may be appropriate to you (the OP) or they may not be.
The midbass or bass being mounted in the horn does help, both with driver spacing and overall size (no separate bass bin). But if you also want directivity control down low then yes the horn will enevitably need to be big.
Unfortunately that is where I seem to be headed, since it is the lower frequency reflections that are harder to control with room treatment. But if your room is more tolerant this may be less important to you. In terms of directivity and power response, many people seem happy with control that begins below 1khz.
Yep. when is comes to directivity control, size matters.
If you're ok with 90 degrees horizontal, 500Hz needs a 22" wide horn (conical)
If you like wider, say 120 degrees, 17" works for 500Hz
If you like wider still, well there's good ole flat baffles huh?
yeah......i can't see the practical application of this either...........just buy a ready made horn and a newer tech 1.4" CD and call it done for home use if you're allowing for a wide cabinet. Newer 1.4" drivers can cross at 800hz or better at home no problem........and they're smooth out past 15khz now as well.
I agree with that. I can't see an easier way of making a powerful dynamic speaker.
It's pretty much what Earl Geddes did, albeit with an OS waveguide that seems useable to not much lower than say 1000Hz.
I think the real magic in a unity/synergy, if such a crappola term exists for any speaker haha,
is it's a point source attempt that takes it lower in frequency than anything else.
And over a decent area, IF and only if, you can handle the size of the horn needed.
Iow, why would i make a unity/syn unless big? I dunno...
Even 1" drivers can play lower than that.. and loud.
Not sure what this means... It seems to be implying there's something in it without going into detail.
In any case, each end of the spectrum has different needs.
LOL…..and that’s what I meant I suppose…..different strokes for different folks. I’ve always advocated for the ideal point source but we all know given current driver tech, that’s not possible. Without actually ’hearing’ one of this things but basing the assumption on the random gushings of folks here and within the Danley circle, a well designed MEH comes as close as possible…………..it’s the compromises that give me pause.
What lead me to discuss the MEH was the possible advantages of smaller version……a 2 way with response down to say 500hz with no concern for directivity below 1500 kHz or so.…..a 1” cd mated with 2-3-4 or so 3” wideband/midrange drivers.
Can the MEH do this better than say some of the top coincident players today?……KEF,MOFI,GENELEC?. I could see a place for a 10”x10” horn with 70 degree coverage or so.
Can the MEH do this better than say some of the top coincident players today?……KEF,MOFI,GENELEC?. I could see a place for a 10”x10” horn with 70 degree coverage or so.
If you can relax your horn size requirement to 12x15", the XT1464 with a 3" compression driver and a pair of 4NDF34's can give you conservatively 300 hz to 16khz, with very good fidelity.
To me, a line array sounds terrible in windy conditions, part of the pattern is interrupted by the wind at times. This leads to unpredictable behavior.