New 3-way coming up.

[Johnloudb]

Edge

"Sound" comments and recommendations from Jed all around.

PARTICULARLY for a dipole configuration of any kind, I do a fair amount of simulation with EDGE before deciding on baffle shape, configuration, and driver locations. Saves problem solving and hair pulling later.

Also, a reminder that it's tricky going from a line source in the midrange to a point source monopole bass source; you can really only balance it correctly at one distance from the speaker. But this might be a good way to get some experience with the RD50, listen to some tools, then do a more optimum design later. I've got a pair of RD50's in storage for a while, and have gone through many "thought experiments" with them, but no hardware yet. Have a whole mess of Fountek ribbon tweeters to use with them, too. I'm still looking for the optimum midwoofer to use with them in dipole, I had hopes for the 7" Aurasound, but it was never released. May end up going with 10" or 12" Aurasound, but that is a bit pricey, and may push the baffle size I'm looking for. Another possibility is the RS270, I still haven't done detailed measurements, and they would be a lot heavier than I would care for (Neo rules!)

Considering a Duelund style 3 way crossover implementation, using the RD from about 400-500 to 4 kHz.

Thanks Jon,

What is EDGE? How much is it?

How many woofers do you plan on using? I'm using 2, 8" 8137A Usher woofers, per channel.
You'll probably finish first ... I may just wait till you're done. :B

[JonMarsh]

Thanks Jon,

What is EDGE? How much is it?

How many woofers do you plan on using? I'm using 2, 8" 8137A Usher woofers, per channel.
You'll probably finish first ... I may just wait till you're done. :B

Emmm, I don't know if waiting for me would be a good idea- there's two or three projects ahead of it in the queue!

You can find The Edge here, and it's free, runs under Windows, even on a Mac in Emulation, it's not too demanding of resources. If you check out the Isiris thread, there's a few posts there about using it.

Has both cabinet modes and dipole modes, as well as a tool for generating compensation networks.

[Jed]

Tom,

How did you remove the damaged veneer? I ask because I might be able to reuse my old cabinets which are about 66L. Only problem is they have some wavey veneer I'd like to remove and reapply. If it's too much of a hassle I'll just rebuild. I used the iron on method but was impatient and applied the veneer when the glue was too wet- then inadvertently left to dry only to find warped wavy veneer.

[ColoradoTom]

Tom,

How did you remove the damaged veneer? I ask because I might be able to reuse my old cabinets which are about 66L. Only problem is they have some wavey veneer I'd like to remove and reapply. If it's too much of a hassle I'll just rebuild. I used the iron on method but was impatient and applied the veneer when the glue was too wet- then inadvertently left to dry only to find warped wavy veneer.

The sides of my cabinets have some slight warping, but since these are only for me I can live with it. The tops had some major problems and I decided to remove the veneer and start over. I set up a rail made of hardwood on each side of the speaker top that was level with the top of the speaker. I attached an oversized base to my router that would rest on both rails. I then set my router for a shallow cut with a straight bit that would cut down through the damaged veneer to MDF. Carefully I routed off the damaged veneer and ended up with very smooth and level MDF base to which I applied a new layer of veneer.

I hope that makes sense.......

Tom

[Jed]

I hope that makes sense.......

Tom

Yup, thanks. I'll have to keep that method in mind. All this corrective stuff sometimes takes as long as building new cabinets however. I guess it depends on the problem though. In my case, I think new cabinets and more patience is in order.

Jed

Image not available

[Jed]

And a downward firing port tuned along the lines suggested for the Three Way Design Study.

Ok, how is this tuning? Dual 10s. 80L tuned to 22HZ.

Image not available

[JonMarsh]

It looks pretty good, Jed- I was wondering how they'd look compared with the RS270 or the NS12a. Subjectively, the plot you've shown with good placement should sound (IME) pretty flat in room to 25 Hz.

If size weren't such a big problem to deal with, I'd suggest moving up to 90 or 95 liters... then you should be able to get a curve like the single NS12a in 76 liters...



In both cases, the limit is around 106 dB, but with the tuning of the 76 liter cabinet for a single NS12, at a somewhat lower frequency, (18 Hz), we have a shallower roll off, a softer Fb corner (at tuning frequency), and 84 dB output at 10 Hz, instead of 76. Now, I don't expect either of us is going to be listening to 10 Hz sine waves, but I do believe this will translate to greater transient weight and impact, as well as tighter response, on some program with deep bass. It's more of an IB sub roll off profile than a ported box.

It just requires thinking like a Sithlord/Master. :W

[Jed]

I gotta think how big I can tolerate these things. 95L would add some more inches to the depth, as it is they're going to end up 19-20" deep for the 75-80L I'm looking at now. Flat to 25HZ isn't too shabbly.

A single 12 would be ideal if it weren't for that really low impedance dip. I know you have amps that will have no problems with that.

[JonMarsh]

Yeah, I never bought real estate when it was cheap, but I have gotten some good deals on Aragons- of course, ThomasW makes my collection (8002, 8008X3, Palladium2, Palladium3) look like an amateur, though I make up in breadth of models what I lack in sheer quantity.

I think your dual 10 system will work out nice- I understand the size limitation, just pointing out how if you "can" stand the size, there might be "room" to squeeze out a little more performance, in a subtle way. In no way is the response prediction you're looking at "shabby". :W

[Johnloudb]

"Sound" comments and recommendations from Jed all around.

PARTICULARLY for a dipole configuration of any kind, I do a fair amount of simulation with EDGE before deciding on baffle shape, configuration, and driver locations. Saves problem solving and hair pulling later.

Also, a reminder that it's tricky going from a line source in the midrange to a point source monopole bass source; you can really only balance it correctly at one distance from the speaker. But this might be a good way to get some experience with the RD50, listen to some tools, then do a more optimum design later.

For positioning the woofers, I've considered moving them forward a bit. Maybe .5 to 1 inch. Thinking, maybe that improve improve integration with RD50 and improve transient response. Have you done this with any of your dipoles?

I agree, only experimentation will really show what works.

[Jed]

The GMK7s are born

I had these boxes, which originally housed a variety of drivers, so why not do something with them? Enter the best variation to date, the GMK7s. The name is from my wife's initials, and these are going to be her speakers. I promised her that if I want to use the drivers she can tell me to get my hands off her speakers! :W

Image not available

[Jonasz]

Nice looking speaker! Do you think the Neo3 could be a replacement for the Visaton?

[Jed]

Nice looking speaker! Do you think the Neo3 could be a replacement for the Visaton?

Absolutely, and maybe one of those Fountek tweeters. The new CD1 looks interesting. Too bad it has a plastic flange.

Edit: Forgot to mention- only with a crossover redesign for a different tweeter to hit the target response 4th order flat delay.

[Dennis H]

Nice, Jed! :T

[Jim Holtz]

Excellent design Jed!

Very well done! :T

Jim

[Jed]

Thanks guys.

[chrismercurio]

Tweeters

The BG Corp Neo3PDR would be a good choice for a lower cost low distortion tweeter.

C

[TacoD]

Your R&D cycles are becoming shorter and shorter . In a year or so you buy as many drivers as Jon

[Jim Holtz]

Absolutely, and maybe one of those Fountek tweeters. The new CD1 looks interesting. Too bad it has a plastic flange.

Edit: Forgot to mention- only with a crossover redesign for a different tweeter to hit the target response 4th order flat delay.

Jed,

You're tripping to the dark side with talk of ribbon tweeters. :rofl: I'm very curious about the new Fountek ribbon also. The price is certainly right and it looks like a great match for the RS52 or W4-1337SA.

The plastic faceplate doesn't bother me a bit. Until recently, Madisound only carried the plastic faceplate versions so I have a whole lot of them in my house when you count the ones in my line arrays. Hiquphon has used a plastic housing for years.

The appearance is identical to metal and I can't see or hear any performance issues with it. I guess, I just don't care as long as it sounds good.

Jim

[JonMarsh]

Your R&D cycles are becoming shorter and shorter . In a year or so you buy as many drivers as Jon

Nah, he was talking about stuff for his wife, if he's married, he's unlikely to ever be able to buy THAT many drivers! But he's getting close pretty quickly! :B :T

[Jed]

Unfortunately, I don't think I did a lot of the drivers I tried in the past justice. I got a pretty good feel for their sonic signature however, but I'm just now getting to the point after measuring certain sets of driver parameters, where I can make better educated decisions as to where and how I should use a driver. I have a long way to go, but my recent success with this last design is giving me more confidence as I start my next all out design, which I really want to get right. Luckily for me there are a lot of different topologies and theories for crossover slopes utilizing the C79. I might try a Duelund approach, since modeling it in LSPCad, the target slopes are similar to some 2nd or 3rd order options for optimization in the tool section of LSPCad.

I'm officially done teaching (done with summer classes) so I can go full speed ahead with the Duet10s. I plan on having outboard crossover networks, and everything as good as I can get it with the finish- my last veneer attempt had a lot of bubbles I couldn't get out. I don't want to rush it.


Jim, as for ribbons, some measure quit well if used above 3-4K- Down the road I'll probably try some, but right now I've got to stay focused [yeah right- dipoles, and Duntech monsters keep lingering in your head].

As for trying out new drivers, we'll see what the future brings. The new Eton's look interesting, but I sure hope they improved the motors. Right now they {look} like revised 7-375 motors, but far from the recent developments from SEAS, Scan Speak, Accuton. The Visaton AL130M looks interesting as well. Most of the time, to fund my hobby, I sell off used drivers that I'm not using at the time- can't afford to have a stockpile of drivers like Jon, Thomas, Taco etc.