Mark Audio CHR-70 Application Thread

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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
 
Re: Mark Audio Chr-70 Application Thread

speakrsrfun said:
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.
 
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:

fast1%20Iso.jpg

fast1%20Left.jpg

fast1%20Iso2.jpg
 
frugal-phile™
Joined 2001
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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
 
Re: Re: Mark Audio Chr-70 Application Thread

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
MJK said:


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.
 
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. ;)
 

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Re: Re: Re: Re: Mark Audio Chr-70 Application Thread

Henkjan said:

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.
 
Scottmoose said:
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. ;)


Scott I love this!! Can I have your permish to build some?

I was just going to build another pair of TABAQ's (I really like them that much) but this sings to me:hbeat:

Are there any further plans or documents I could have? I'm going to whip up a sketchup for this tonight.
 
By all means. That's what it's there for. :cheerful:

I hope it'll sing to you at any rate. ;) They're not going to win any neutrality awards, that's for certain. Resonant pipes never do -opinion tends to be polarised; people either love them to bits, or loath them beyond all description. I suppose they're the speaker equivalent of 'ah, what the heck, let's have some fun.'

Funnily enough though, I suspect, if positioned & damped to suit the space they're in, they'll perform better than many people would believe. The Feastrex cabinets for e.g. got some positive comments, and these are basically quite similar.
 
Compact double BVR done (provisionally named Lotus) -like the above, it's intended for modest spaces / SPLs, but should be quite a nice cabinet. CAD plans will be on the way at some point in the near future when Dave has chance to draw them. ;) This is the baby brother to a similar cabinet just completed (provisionally named Jaguar) for the Alpair10.
 
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Scottmoose said:
Dave's going to strangle me, as he wrote that before I sent another batch to him, including one for the Alpair6 that will probably see me certified (at last). :bawling:

Novel to be sure (how often is something really novel). A cross between Mileva & Vampyr, looks like it could be an off-spring with teeth ;)

Mark Audio seems to have really gotten Scott's mindJuice flowing.

dave
 
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