The CHR Array

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Mark Audio CHR-70 Line Array - Madisound News Blog

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As well as the Arrays, some useful ideas, and a good bibliography.

dave
 

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Is it too soon to start nagging Mark for an array CHR?

I'm thinking a much smaller diameter alloy or steel frame so the FRs could be
packed in much tighter? I enjoy my 2-way line array crossed at 4.3 KHz but
eventually will replace the 5 inch woofers with 4" and would love to pack them
in really tight. More drivers = higher efficiency and power handling...
 
Is it too soon to start nagging Mark for an array CHR?

I'm thinking a much smaller diameter alloy or steel frame so the FRs could be
packed in much tighter? I enjoy my 2-way line array crossed at 4.3 KHz but
eventually will replace the 5 inch woofers with 4" and would love to pack them
in really tight. More drivers = higher efficiency and power handling...


The query has already been put to Mark as to possibly revisiting the rectangular frame that we saw in earlier version of the Alpair6 - if for no other reason than their very clean aesthetics in a line array . I've heard both paper and metal versions of the latest gen of this model, and they're very nice indeed.

No doubt there are limits to the number of driver models Mark would want to pursue without assured marketability/demand, a CH price range descendant of the Alpair5 (maybe even in paper) could be interesting.
 
No doubt there are limits to the number of driver models Mark would want to pursue without assured marketability/demand, a CH price range descendant of the Alpair5 (maybe even in paper) could be interesting.

Very true,

I would assume the only way he would make a metal framed, array specific speaker with the CH is if the CHR-70 sales skyrocket due to the availability of
the array design. It would be great to have a squared off alloy or steel frame but these days....I'm sure folks buying 36 CHRs to build arrays with would be on the low side.
 
I may be mistaken but I seem to recall one of the new MA drivers have a removable plastic bezel? Perhaps Mark could simply make a square bezel and buyers could buy them separately for line array use?

Mark also seems to have proven that drivers with a plastic frame are a viable alternative with minimal drawbacks.

Even though the CHR-70 is a great product for the price, perhaps as Chris said, a CHR/P-50 would tick more boxes suited to line array use? Cheaper to manufacture/buy, closer C/C spacing and the individual bass response per driver becomes less of an issue in a Line Array with EQ, active or otherwise.

I wonder what sort of price Mark could produce a CHP-50 for? You have his private email don't you Chris?

Sorry Mark :)


Dean
 
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I may be mistaken but I seem to recall one of the new MA drivers have a removable plastic bezel? Perhaps Mark could simply make a square bezel and buyers could buy them separately for line array use?

Mark also seems to have proven that drivers with a plastic frame are a viable alternative with minimal drawbacks.

Even though the CHR-70 is a great product for the price, perhaps as Chris said, a CHR/P-50 would tick more boxes suited to line array use? Cheaper to manufacture/buy, closer C/C spacing and the individual bass response per driver becomes less of an issue in a Line Array with EQ, active or otherwise.

I wonder what sort of price Mark could produce a CHP-50 for? You have his private email don't you Chris?

Sorry Mark :)


Dean


mea culpa also - like Mark needs us to compile an even longer wish list -

and no, I don't have his private e-mail - but he certainly does respond to forum PMs
 
I'm working on a corner line array design. If the factory measurements are to be believed, Mark is considerably ahead of other full range vendors in off axis uniformity in the top octave. I'd love a version of the CHR with frames that allow closer spacing. Additionally a smaller driver around 2"-3" would be great. Higher than typical impedance might be useful for folks doing Keele arrays.

I don't know the fixed costs involved in driver development, but with even just a handful of us buying ~50 drivers each perhaps we're closer to this being viable than it might at first appear.
 
Next year I am going to be building corner arrays as well and a CHR-70 with as small as possible square stamped metal frame (to reduce cost) would be just the trick. Cost has to be minimized in such an application.

Very true,

I used the factory close out Sony 5" woofers for my 2-way line arrays. Decent, low power speakers and by adding liberal mounts of plumber's putty, it eliminated the ring from the stamped metal frames. Now that I know I like the "big" sound of the things, I can figure out what to eventually replace the woofers with.

My interest is in 3 to 4 inch speakers with a minimum of 85dB 1w/1m, 4mm+ of Xmax with an Fs lower than 75 Hz. The CHR/Alpair meet this but the very wide frames on them screw up the center to center spacing :( The twelve 5 inch woofers will be replaced with sixteen 3 to 4 inch woofer/full ranges and the MA drivers seem to be the perfect driver. Having a line array that can be configured for 2 way or full range operation would be a unique option.

I have plenty of time to wait--subwoofer project next then various other things.
 
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If a CHR-6 could be constructed that would also work. Basically the array needs to be able to do 100dB @ 80Hz with max 2mm peak to peak cone moment, full range initially to reduce costs and then possible replacement with a 2/3 way array based around planar transducers.

At the moment Hi-Vi square frames are looking the best bet:
Hi-Vi B3S 3" Full Range, Copper Color Cone: Madisound Speaker Store

but looking at the cone (sticking out surround and no dust cap to act like a wizzer) the dispersion is going to be much worse than Marks drivers
 
The CHR/Alpair meet this but the very wide frames on them screw up the center to center spacing

I'm working on understanding this point better atm in the context of CBT arrays. Keele's math assumes point sources, which clearly misses some of the behavior. I suspect that larger drivers show less interference than mere c2c distance would suggest. Of course, larger drivers present their own individual beaming problems, which will have implications for arrays.

In any case, minimizing un-driven area along the length of the line is almost always going to be better, so I'd love a truncated frame CHR. I'm not certain smaller will be particularly useful to me however, given how mild the CHR's beaming is.
 
I'm working on understanding this point better atm in the context of CBT arrays. Keele's math assumes point sources, which clearly misses some of the behavior. I suspect that larger drivers show less interference than mere c2c distance would suggest. Of course, larger drivers present their own individual beaming problems, which will have implications for arrays.

In any case, minimizing un-driven area along the length of the line is almost always going to be better, so I'd love a truncated frame CHR. I'm not certain smaller will be particularly useful to me however, given how mild the CHR's beaming is.

Very well put,

I did plenty of reading about line arrays, both pro and con. The c2c distance did give me pause so I went with a 2-way design crossed at 4.3 KHz. In theory it should suffer from excessive beaming since it uses 5" woofers with a 5.4" center to center distance. Sitting down and standing up quickly, I can hear it but generally I don't. The experiment works but I want more :p

The CHR would be the perfect driver if I could get the drivers packed in tighter. The HiVi is a strong contender for a 2-way but I would like the option to use full range or 2-way with a simple jumper on the back. If the beaming bothers me running full range, there is always the jumper to bring in those 48 tweets in a 6 foot line. The combination of high Xmax for a FR, decent sensitivity, great extension past 20 KHz and a frequency response that is smooth should make arrays easier to deal with.

Maybe a sheet metal frame to pack them in tighter but use the composite bonded to the frame to cut ringing? Mark can take his time, I'm not in the mood to cut up my bezels just yet and cut 20 new holes in each box. Not yet but eventually. :cool:

Keele's curved arrays look good and he crossed them over at 1 KHz....the half wavelength distance c2c is the idea. A very interesting design but not for my garage.
 
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