RM V60 is coming....7-6-5-4-3-2-1-0

Brian Cheney · « **Reply #140 on:** 16 Dec 2006, 04:07 am »

You can completey absorb the back wave or let it all pass, or something in between with the wedge-shaped foam damper. I'll post pix of this next week.

The 150 lb wing is made of 2" MDF and is both rigid and lacking parallel walls. It works well.

John Casler · « **Reply #141 on:** 16 Dec 2006, 04:10 am »

Quote from: Brian Cheney on 16 Dec 2006, 03:34 am

This is a high sensitivity system.

Tweeter is 100dB/1W/1m, mids are 95dB, 6.5" woofers are 92 dB. You can get a Powered Bass ($1200pr) system for the 6.5's and then only have to amp mids and tweeters. Depending on room size even a small SET should work.

The outboard subs are, of course, powered, with plenty of headroom (92dB/1W with a 1000W amp).

Just imagine these babies with some sweet, sweet tubes.

Brian Cheney · « **Reply #142 on:** 16 Dec 2006, 04:45 am »

3 weeks and you'll be hearing 60's on OTL space heaters, the 20 tube M2 monoblox...

hmen · « **Reply #143 on:** 16 Dec 2006, 04:57 am »

Quote from: Brian Cheney on 16 Dec 2006, 04:45 am

3 weeks and you'll be hearing 60's on OTL space heaters, the 20 tube M2 monoblox...

Do you mean the Atma-Sphere MA-2?

Brian Cheney · « **Reply #144 on:** 16 Dec 2006, 05:08 am »

I stand corrected, the MA 2 space heater/OTL's.

RGordonpf · « **Reply #145 on:** 16 Dec 2006, 05:33 am »

Hi Brian,

Gorgeous cabinets and a unique solution to many pesky speaker design problems. I can't wait to hear these at CES.

Can the same design principles be used for a smaller speaker, say something equivalent to the RM30? Many of us with smaller listening rooms don't have space for the RM V60 and we don't need as many drivers as we don't listen at high dB levels. A smaller and more affordable version would probably sell very well. Just a thought.

RM V60s and Atma-Sphere OTLS

Brian Cheney · « **Reply #146 on:** 16 Dec 2006, 05:38 am »

I could make it smaller but not much cheaper. The cabinet is technically very difficult to manufacture, as you can see, particularly when made to this cosmetic level. We'll see how the market likes this big fellow before considering smaller siblings.

James Romeyn · « **Reply #147 on:** 16 Dec 2006, 05:45 am »

Quote from: John Casler on 16 Dec 2006, 12:49 am

Quote from: PLMONROE on 16 Dec 2006, 12:47 am
John, you really know how to keep a person in suspense!. They haven't gotten here yet

No matter Big B, has the real thing already up.

Correction, Jimbo! Man you guys should see the crap loaded onto Brian's work computer! There is so much kid's stuff on it it's ridiculous! It took an hour to get those pics from the camera to the site. Brian owes me steak dinner at CES.

hmen · « **Reply #148 on:** 16 Dec 2006, 05:47 am »

That should be incredible. I've been using the M60 (eight tubes per side) with my RM2's and now my RM40's. The Atma-Sphere amps and the ribbons are the perfect combination. The best transient response and cleanest midrange and upper octaves I've ever heard. You could probably blow the roof off with the V60's and my amps. The MA-1's (14 tubes per side) are probably overkill. With the MA-2 you probably power the subwoofers as well. This should be amazing.
As far as these amps being space heaters - I keep windows open in my basement all winter. They're open right now.

John Casler · « **Reply #149 on:** 16 Dec 2006, 05:48 am »

Quote from: RibbonSpeakers.net on 16 Dec 2006, 05:45 am

Quote from: John Casler on 16 Dec 2006, 12:49 am
Quote from: PLMONROE on 16 Dec 2006, 12:47 am
John, you really know how to keep a person in suspense!. They haven't gotten here yet

No matter Big B, has the real thing already up.

Correction, Jimbo! Man you guys should see the crap loaded onto Brian's work computer! There is so much kid's stuff on it it's ridiculous! It took an hour to get those pics from the camera to the site. Brian owes me steak dinner at CES.

Hey Jim,

If you were the camera man, you deserve a lot of credit. The shots were excellent.

James Romeyn · « **Reply #150 on:** 16 Dec 2006, 05:52 am »

Thanks John!

Nope, those were taken by Brian on his $300 special.

I will get my Eos Digital pics loaded asap. Brian said to start a new thread so I will do as mastah says!

The pics don't do those things justice. John your guy Paul is going to have a baby when he uncorks his cartons holding these things. In person these humiliate every other speaker I've seen, & I've seen all or most of the best finished money can buy.

JLM · « **Reply #151 on:** 16 Dec 2006, 12:06 pm »

Curious...

How does the slot spread the treble response vertically across its entire length (probably covered elsewhere/previously)? This is important, as a mis-match between vertical dispersions in the midrange and treble would be undesirable.

Did you play much with the wing angles? (Compared to most open baffle designs these very "tight".)

Did you consider unequal width wings? (to spread out the dipole baffle step effect)

Is the foam delivered in various thicknesses so the customer can find what works best?

What motivated you to go in this new (dipole) direction?

I'd wish for a smaller verison, with:

Point source dispersion (perhaps two midrange drivers in a MTM configuration);

Less looksome veneer (these blow away anything else in the room and I don't want to replace all the furniture);

Lighter/thinner wings (perhaps user installed wings and add braces as there is little pressure against them).

BrunoB · « **Reply #152 on:** 16 Dec 2006, 01:35 pm »

Quote from: JLM on 16 Dec 2006, 12:06 pm

Curious...

How does the slot spread the treble response vertically across its entire length (probably covered elsewhere/previously)? This is important, as a mis-match between vertical dispersions in the midrange and treble would be undesirable.

Curious too ...

Bruno

Brian Cheney · « **Reply #153 on:** 17 Dec 2006, 07:23 pm »

Slots are well known to improve vertical dispersion. As another designer once told me, he measured a substantial improvement in vertical dispersion (several feet above the baffle) with slot-loading, but found it difficult to make the slot narrow enough to provide true constant directivity over a wide range horizontally. Well, now the slot is narrow enough and the improvement in vertical dispersion is easily audible.

Wings were made thick and heavy to reduce their secondary output, as the surface area is very large. The driver arrangement is MTM with tweeter at ear height. I did extensive experimenting with wing opening angle and tried to make the wedge as tight as possible to reduce the visual impact and footprint of the system. I did not try unequal wing depths, and that is an idea worth pursuing.

PLMONROE · « **Reply #154 on:** 17 Dec 2006, 07:59 pm »

[/quote]

Quote from: Brian Cheney on 17 Dec 2006, 07:23 pm

I did extensive experimenting with wing opening angle and tried to make the wedge as tight as possible to reduce the visual impact and footprint of the system. I did not try unequal wing depths, and that is an idea worth pursuing.

Well if it is proved that one wing needs to be longer than the other I don't see it as a problem. After all it would be pretty simple to take an ax and chainsaw and trim one wing down a bit.

Brian Cheney · « **Reply #155 on:** 17 Dec 2006, 08:10 pm »

Good idea, will include chainsaw with each pair. It'll be fun, sorta like trimming the Xmas tree.

John Casler · « **Reply #156 on:** 17 Dec 2006, 10:54 pm »

Maybe "unequal lengths" would be good

John Casler · « **Reply #157 on:** 17 Dec 2006, 10:58 pm »

As I mentioned before, we are taking "pre-orders" on the RM v60 and the response is incredible.

I think we have orders and commitments for 4-5 already

B, said he "hopes" to receive his production cabinet/frames, the last of February, and after clearing customs shipping ASAP after that.

Brian Cheney · « **Reply #158 on:** 27 Dec 2006, 07:43 pm »

I will follow up briefly on yesterday's posting to the thread "VMPS will show and demo the RM V60 at CES" concerning the sound quality of the system.

As I explained, the V60 combines a diffraction-slot loaded, constant directivity, 180 degree front firing mid/treble ribbon array with a reverse horn loading of its back wave, accomplished by means of sharply swept wings which eliminate both edge diffraction and cancellations from the Dipole Effect on rear radiation.

Horns are renowned for concentrating energy where you want it and more than a few listeners find their sound impactful and exciting. For many high end speaker designers, however, horn loading is anathema due to the coloration introduced by reflections inside the horn throat, a phenomenon called the "megaphone effect". It would be highly desirable to retain the controlled directivity of horn loading (which would allow you to reduce mid and high frequency room reflections) without its characteristic honk.

My solution is to absorb the inside throat reflections with an adjustable damper. On the V 60 it's a 54" tall, wedge-shaped foam column which the user can place inside the wings to either completely absorb the back wave (like a standard sealed enclosure), or allow partial dipole operation by moving the damper far enough back and away from the ribbon panels and wing side baffles.

The results are absolutely remarkable. There is a noticable increase in focus and linearity over open-back and full dipole planars, much improved imaging, and a palpable presence and authority to the sound, the radiation pattern of which is now much more like like voice and instruments exhibiting similar cardiod-with-tail dispersion. Music flows from the speaker and fills the room in a manner I have not heard from any other design.

I think V60 owners will find its performance thrilling and faithful to the music regardless of type, output level, room size, placement or listening position.

Brian Cheney · « **Reply #159 on:** 29 Dec 2006, 04:28 am »

Today the prototype VSS sub ( a modded Larger) joined the V 60's for the first time.

It turns out they play well together, although the sub is finicky about its crossover frequency (71Hz, not 70Hz or 72Hz with the filter slope I'm using).

So far only one VSS is playing, tomorrow there will be two, as there will be in our CES demo system.

Things are going well.