Newform ribbons

[AndrewM]

Hey everybody, I'm thinking about building one of the Newform Research http://www.newformresearch.com 645 kits, or at least getting the ribbon and then building a little different cabinet under them, basically something that will have the same fast transients and detail that the ribbon will have, and go a little lower (and with more authority) than what the dual Scan Speak 7"'ers will do.

Anyways, my question here is how can I make them look a little better, just having a cabinet on the floor with a 45" ribbon sitting on top is, well, just not very good looking. I was thinking of doing something like this \_/ With the ribbon in front and then having some 1x6 (or around that) planks of cheery or something extend up with the ribbon and angled back, just to give it a little more flare, make it look like something more than a coat rack without any pegs. Any other ideas?

Andrew

[ThomasW]

You must have inherited some money

I'm curious as to how these compare price wise, to buying Maggie 1.6s, with the conversion to cdn dollars.

These speakers get good reviews. I do have reservations about getting a "seamless" transition between the ribbon and the cone mid/woofers. Primarily because the XO point is so high.

You can make any frame you want just don't have any "solid" surfaces near the ribbon. This would cause diffraction problems.




theAudioWorx
Klone-Audio

[AndrewM]

No inheritance for me, but if they sound as good as every single review of them I've heard, I think I will have saved money compared to anything else that is comparable that I know of.

I have no idea about the pricing, plus the Newform's come with all kinds of different ways to buy, the whole thing for $2200 (bolt the ribbon to the cabinet), buy the kit for $1500 (build the woofer cabinet, assemble x-over), or just buy the ribbon for $1000 (find your own mid/low drivers). Plus people always say to ask if they have any demo units, which usually cost the same as the kit price (plus they are usually broken in).

I also wonder about how seamless the transition is, as this is one of my biggest complaints about Martin Logans, the woofer they are using just doesn't sound right with ELS panel. Now I imagine that this can't be much of an issue as I have never heard an owner mention it when talking about them. I'd also need to find some drivers that would mate well to the whole thing, Focal, ATC, Skaaning, Seas, Scan Speak....something that will match up well to the ribbon. Or maybe just leave it the way they sell it, but I have to believe I can do better than dual 8545's for the 1000Hz and down.

I just need to find some way of making them even semi-pretty to look at so I can get them past the front door without getting thrown out of the house.

Andrew

[ThomasW]

The ScanSpeak drivers John Meyer's uses are some of the best drivers available. That's not where the problem would be. Its the 1000Hz XO frequency. That XO point is high enough to be smack in the middle of the critical part of the midrange, not good IMO.

The transition from a cone to a ribbon/leaf, etc should be as low as possible. realistically this means 250/350Hz is the highest frequency used. This is why I'm considering the Newform for extremely high quality "mid/tweeters" to be used with the B&G RD planars. The B&G's go low enough to use a 300Hz XO point, but they are soft and ragged in the high-end. So XOing them to the Newforms around 2500HZ should create an expensive, but astounding speaker.




theAudioWorx
Klone-Audio

[AndrewM]

Oh, I'm certainly not saying that the Scan Speak 8545's are bad drivers, quite the opposite, I agree that they are one of the best around. But there are better (albeit for more money). Plus I would like to try something a little different, or more to the point get more bass out of them, I think the quality of bass will improve if you use a 10"-12" driver, but there's no way to make low high quality bass and make it run up to 1000Hz to x-over to the ribbons. Hence why I would use something like a 5"-6" mid to use, and then a bass driver. I don't even know if there is a transition problem with these speakers as I've never heard them, and I've never heard any complaint about it like I have with some other hybrids.

I'm interested in the project you are doing also, although I think they will end up being a little to big for my room. How high up do the B&G's make it before getting to that ragged side?

Andrew

[ThomasW]

I don't know what is really going to be better than the ScanSpeak carbon fiber drivers. Possibly the Cabassee. But man those are expensive!

If you use a "filler driver", you'll probably still have the same problems at the XO point. Why? The transient response of a cone is much slower than any planar/leaf/ribbon. The ear will perceive the differences in the transient response as a blurring of the sound. This is what many hear with Martin logans.

The B&G top end response depends on the size /shape of the baffle. That's why I need to experiment with differing baffle size and shapes. The Swan Dul'cet Model 2 clone, will probably end up only 2" wider than your 1.4's. And it can be built either 50" or 75" tall.

Sorry for the delay in my responses I'm having some trouble with the new computer system




theAudioWorx
Klone-Audio

[AndrewM]

Well, the other idea would be to use the ribbon in the same way that you would with a "normal" ribbon tweeter, set the x-over higher like somewhere in the 2-3kHz range, or maybe even higher depending on the midrange driver being used, but then I think you may be better off going with a Raven 2 for less money (for probably a better tweeter), you just don't have the 40+" of ribbon. Plus if you use a good midrange that will extend up into the 5-6Khz range, but have the cross-over lower, you may be able to get away with 6db x-overs, or maybe even trying out a series x-over with it. That's all speculation, without doing a little experimentation first, but it's certainly a possibility. And you still may end up with the transition problem. To bad the Raven 3's are to damn expensive....

I think you may have confused with Mr. Pratt, as I don't have a set of Maggies, just a set of Adire 281's. I could live with 50" tall, as long as they didn't get to wide, but more important is how far from the wall they need to be, my 281's are about 2.5-3 feet from the wall, and I can't do to much more than that.

So what computer problems are you having? You just built a new AMD system didn't you, is it any good, I've been thinking of making the switch from Intel myself.
Andrew

[Andrew Pratt]

Thomas unfortuntaly its not I that wants to do this project though I it would be nice Guess there's to many Andrew's around here

[ThomasW]

Oops my bad......... :?

I apologize yes I did have you confused with Andrew P. And was wondering why this conversation was occurring a second time.

Ok, Andrew M.

RE: Computer issues. This is my first Athlon PC. There seems to be an issue with the Abit MB and the drivers for the Matrox G450 Dual head video card. The system occasionally hangs during the pause, just before writing the icons to the screen. This is an intermittent issue. When the desktop does load, the sytem is very stable. And fast....

Now back to your speaker design, this time focusing on your true items......

Something to consider with the use of any ribbon/leaf/planar, is that the vertical dispersion is "basically" limited to the physical height of the tweeter. So something like the Ravens, Hi-Vi Research leaf or the new Phillips, is that there will be a very narrow "sweet spot". So if few people listen and they all can access the sweet spot, no problem. But if it's several people watching a big TV, some on the floor, others on chairs and a sofa, there many be issues with everyone hearing the full spectrum. This is the area where the Newforms have the advantage due to the height of the ribbon.

IMO there are 2 areas where the 645 will have issues. First the 1Khz XO point, and second it won't have any real bass punch. The drivers simply aren't big enough to move a lot of air. A sub will solve the second issue.

RE:Hiding the ribbon. Make a frame with metal rods on the front corner of the box. Put wood members on the rear corners. Then stretch a grill cloth from one wood piece to the other. The there is so little free space beside the ribbon that using wood there would probably interfere with the dispersion pattern.

Also the Maggie 1.6's cost $1600. And are truly one of the best values in audio today. They can be improved by using a midbass bin with a couple of 8's crossed over at roughly 250Hz as a platform/stand for the 1.6s. This takes the midbass load off the panels, and allows them to do what they do best, 250 Hz and up. They do need a good amp, because they like power.

http://www.magnepan.com/1-800-474-1646/index.html

6db/octave XOs look good on paper but the reality is that there are numberous sacrifices necessary to get them to work. These include using limited selection of drivers. Usually needing more drivers to keep units operatng in their most pistonic range. Limited power handling, etc, etc.

Series XOs also fall into the "looks better on paper" area. Although these they have a cult following, they aren't truly practical either. There a reason companies with million dollar R&D labs don't create series XOs for their speaker designs.

Also unless you have access to programs like LEAP, LspCad, Laud, etc and have considerable experience designing XO's, this is something better left to the pros.

I don't want to provoke a flame fest with my statements regarding 6db/octave and series XO.

JonMarsh and others designed/built and marketed a "phase coherent" 3way design in the mid 1970's. Somewhere, there's a picture taken from the scope, that was being fed by a microphone. The mic was placed in front of the speaker, while it was playing a square wave. The picture shows the same square wave, being reproduced by the speaker. So yes it can be done. But these days the question is, why would anyone want to?




theAudioWorx
Klone-Audio