Mark Audio CHR-70 Application Thread

[speakrsrfun]

Since I have a couple pairs of these laying around awaiting a glorious home I figured I'd start a thread for others to post their ideas and design applications into.

With that being said I have a few designs I may go with...

I'm intending on using two per cabinet for higher output and power handling, plus transients sound much more alive in pairs.

So my two ideas are a floor standing thin tower with the two drivers mounted in a Onken style arrangement, or the same type of enclosure in a BR alignment. BR would be about 30-35 litres tuned to the 40ish area. These would run out of gas at louder volumes with the lower registers but would sound great if used with 20-50W gainclones and moderate volumes.

Or I may try another attempt to augment in a FAST with a single CHR70 and a single W14. CHR70 in a aperiodic damped enclosure and the Sliverflute in a BR crossed at 350Hz.

Anyway this will be my thread for posting my results with these little guys so anyone else who wants to give some input it would be appreciated dearly by many other folks.

Happy Listening

Speaks

[MJK]

Originally posted by speakrsrfun
I'm intending on using two per cabinet for higher output and power handling, plus transients sound much more alive in pairs.

I had similar thoughts myself, the drivers are so affordable that putting multiple drivers in a box seemed like a natural next step.

For higher output I think you mean wired in parallel, with a Re of 3.6 ohms this would mean a combined DC resistance of less than two ohms. That starts to make me a little uncomfortable.

Four drivers in a box with pairs wired in parallel and then the two sets wired in series returns the DC resistance to the 3.6 ohms, maybe that would work better. Still a low load for some amps.

[raypalmer]

I've got a similar FAST lingering in the design stage right now, only mine will use a TB W4-1052 ex. range and W5-1138 sub.
Similar ideas maybe only yours will have much better drivers!

Maybe by the time I get to building these I'll swap out the 4" TB's for Mark's though. I'll watch your progress!

Credit for the design principles to planet10.
See attached cute pictures:

[planet10]

Since the hole fit, i popped a pair of my CHR70 into Aiko. Not the kind of box you would think to put it in, but Scott had done a sim with the CHR in a horn we did for a client that didn't meet the goals (so the design was stashed) and the sim suggested CHR might well work. In Aiko it is lumpy enuff to rule it out.

dave

[speakrsrfun]

Thanks for pointing that out Martin, I shouldn't have used the word OUTPUT when what I meant really was sustainable volume without strain.

I'm liking how the CHR-70's model as a pair in the ported tower, although the 35ltrs seems quite large for the two tiny drivers....

I'd like to also investigate a destop Transmission line for a single CHR-70. I think you'd get good Near feild output down to 40hz or so and they have pretty pinpoint imaging if you ask a brother so something to be placed dektop maybe 12-15" tall 5" wide, I don't know it could be 15" deep???

Lots of thought and little dust flying at this point, Peace.

Speaks

Originally posted by MJK


For higher output I think you mean wired in parallel, with a Re of 3.6 ohms this would mean a combined DC resistance of less than two ohms. That starts to make me a little uncomfortable.

[Henkjan]

Originally posted by speakrsrfun
......I'd like to also investigate a destop Transmission line for a single CHR-70.

something like this? (this example is tuned at 50Hz)

[Scottmoose]

And now for something completely different...

Kind of like a Nessie, but I ignored everything in the Nagaoka design methods (whatever they are -I really didn't bother looking, I prefer to do things my own way). Excuse the rubbish drawing and the equally duff pdf -I couldn't make the gif small enough to upload on the forum.

No, it's not going to be the most 'accurate' box ever done for the CHR. That wasn't why I did it -this is a deliberately characterful cabinet for use in modest rooms that should give some decent bass. Besides, if Feastex do something very similar for $19,000, no reason why we shouldn't have some fun too.

[hm]

Why not a double horn like the
TROMBONE or KORNETT?
Bass, soundstage.

[Scottmoose]

OTOH, why not a BIB; BVR; single or double horn; MLTL; ML conical horn; TQWT; TL; double BR; and OB, aperiodic, or sealed box with supporting woofers?

Bass, soundstage.

[HareBrained]

Originally posted by Henkjan

something like this? (this example is tuned at 50Hz)

That's a nice design, Henkjan. The taper is a little severe, IMO, but I imagine the bass output would still be tunable.

Personally, I like the idea of a dual chamber reflex with dual ports for a desktop or bookshelf. Models show a very nice response in a net total volume of ~7.5L. It would help with power handling for the single driver implementation.

Speaks, 35L does seem large considering 10L is the recommended size by Mark. If you want a floor stander, consider it as a ML-TL. That might be more feasible.