Mark Audio CHR-70 Application Thread

[Ian444]

audiosteve,

I was hoping no-one would ask these questions

I wasn't aware that anyone had compared the dual driver version to the single. I did think about doing a dual, but that's as far as it got... To answer your question I find nothing lacking, but I have never owned decent speakers before this. When I first ran them, it was like a sub had been added, compared to my old bookshelf speakers (Klipsch RB-61). The hi and low frquencies have very good clarity, voices sound sweet. The clarity is what I really like. This "new-found" bass inspired me to build some BIB for the CHR-70 (with my mate Dave who has them at his place about 4 hr drive from here) and also we cut some wood for BIB for HiVi M4N which are nearly completed at my place. I wanted to see what BIB could do compared to the Lotus. I'm new to full-range and building so I'm in some sort of exploring mode at the moment. Dave had heard my Lotus, and wanted me to help him build some Lotus for his daughters' birthdays, so I drove up there, he has all the power tools, table saw etc, and I thought why not knock up the BIB's while we're at it. Dave was really impressed with both speaker types.

Comparing the CHR-70 Lotus to CHR-70 BIB, I have no realistic/concrete results. We built the BIB's last, so the drivers were less broken in than the ones in the Lotus, which weren't broken in either. Anyway we connected the BIB's to his system, previously we were listening to Lotus, and we both thought they sounded great, they weren't up against a wall as such and miles away from the ceiling, but still did a nice job. That was at night and one of them still had clamps on it. Next morning I selected a song for testing and listened to the BIB's and then swapped the Lotus back in. The Lotus had a bit less deeper bass, but the bass of the Lotus was more controlled, tighter bass. The Lotus high freq was stronger too. So the BIB's sounded great on rock'n'roll, real party animal "live sound" stuff, Deep Purple etc, and the Lotus was more impressive with clarity and the freq response more balanced. But there are a few big "buts", the BIB drivers had very little time on them, less time than the ones in the Lotus, and the BIB's were not optimally positioned either. As far as tuning/damping/stuffing goes on the BIB's, I put my ear in the open end and could hear up to the lower frequencies of the male vocals, so I'm not sure if that is enough stuffing in there? Is that 300Hz? Maybe over-damped? Both speaker types had very similar volume output for the same power input. After that quick comparison I had to drive home, and probably won't get back there for a while.

Although a long reply, it doesn't answer your questions very well, but early impressions are better than nothing I hope. Like italynstylion, I really love the Lotus. His are dual and beautifully finished, I think he inspired me to build mine, seeing the pics and report, thanks mate! It will be interesting to hear the BIB's with the HiVi M4N tomorrow, can't wait...and Planet10 has some interesting designs too...I bought a small table saw from ebay (Triton) a few days ago, I dunno whats going to happen from here on...

[audiosteve]

Thanks very much for your reply Ian. This is helpful information. If your impressions of the speakers changes with time, please let us know.

Cheers

[chrisb]

Not to belabour the "obvious", but something to keep in mind when comparing applications with single vs dual Mark Audio drivers (including CSS EL70 ) is the synergy of amplifier output stage with varying impedance load.

Not all SS amps and even fewer tube amps would be comfortable at "realistic" playing levels with under 2ohm load presented by a pair of these drivers in parallel, and many could exhibit different signatures at the (approx) 4 from a single and 8 resulting from series connection of dual drivers. Depending on the individual system, this could swamp the difference in acoustic performance between single and dual drivers.

Presumably a quality autoformer could render this issue moot, but that could equal the cost of some budget amps.

[markaudio]

Hi Guys,
A quick note to let you know the new CHR-70 will be available soon. I've completed the production. The driver is updated with new cones (Multi-formed), revised coil and rear suspensions.

Here's a pic. I'll be back to the studio later next week so will post in the forum's new makers section.

Thanks,

Mark.

[Toaster]

Ah- so is that why the grey ones are out of stock ATM? If they are coming out soon I'll transfer the currently in-play order to a pair of the new ones...

[italynstylion]

Originally Posted by markaudio

Hi Guys,
A quick note to let you know the new CHR-70 will be available soon. I've completed the production. The driver is updated with new cones (Multi-formed), revised coil and rear suspensions.

Here's a pic. I'll be back to the studio later next week so will post in the forum's new makers section.

Thanks,

Mark.

Mark, do we have any new TS paremeters for these? Also, how would you say the new design is better?

[planet10]

I have just released the plans for a milliSized CHR-70 enclosure that debuted at the 6th Annual Vancouver Island diyFEST.

dave

[markaudio]

Originally Posted by italynstylion

Mark, do we have any new TS parameters for these? Also, how would you say the new design is better?

Hi Steve,
Humble apologies for not replying sooner. Here's the link to the new CHR-70 thread in Markaudio section of Manufacturers, all T/S info there. I'd personally say the new multi-form cones are a nice step forward. Derek Shek (Miniwatt amp maker) and me were playing the new drivers in 10 litre BR's, Derek's tiny 2.5 watt with switching power supply - smooooooooth as silk with more detail, clarity. Derek knows both old and new drivers, got the big thumbs up for him for the new model.
Amazed at Derek's tiny 2.5. Thought it might struggle pushing the CHR's but it didn't. Played loud and clear, I learn something new every day.

Email me if you need more info - thanks

New CHR-70

Mark.

[gychang]

Originally Posted by planet10

This might help

dave

Slick design Pensil70, thanks for clear drawing. What is the purpose of "simple filter"?

gychang

[planet10]

I just copied Marks original drawing... looks like BSC.

dave