Raal 140, Neo10, AE Dipole 15 in the works

THWO · « **Reply #160 on:** 28 Sep 2012, 03:18 pm »

What another wonderful project, congratulation, Bill.

And now even going for 18"... Very nice. Do you deem support by a subwoofer really necessary, despite the big woofer´s surface area? In case the baffle step loss seems to big, how about beefing the baffle up a bit by some U-frame support on the back side? Besides, this could eventually help reducing vibrations caused by the additional moving mass you mentioned.

Just my 2 cents...

Keep going! And showing us some pictures will sure be well received, I guess...

Till

studiotech · « **Reply #161 on:** 28 Sep 2012, 08:42 pm »

Thanks for posting Bill! You know, you are man after my own heart...I really wanted to use the TC Sounds 5100 too, but the money was running out and I too, was not sure I wanted to run them up to 250-300Hz. I settled on using the sealed Rythmik Servos. Please start a thread for yourself. We all love to see 'ugly prototypes', don't we folks?

There is a guy on DIYAudio forums who I've been kind of mentoring (more like bossing around! Haha!) who just order a set of these 5100s also at my urging. He is going to use a midbass though to not need to run the 5100 much over 100hz. Then hand off from the maybe 10" midbass to a pair of 4" Scan Illuminator mids and finally the dipole version of the Raal 140-15. Whew, makes me light headed just think about it!

As far as my system goes, I got a new laptop and have been having issues with my crap, old Tascam USB interface that is no longer supported with updated drivers, so I'm getting something new for measurements soon AND this weekend I'm going to reorient the whole room 90deg around to try to get the speakers MUCH father from the side walls and more symmetrically placed. We'll see how that goes. Once I get good measurement capability back, I promise to return with some plots.

Oh yeah, I also blew out one side of Neo10s due to a stupid oscillator at full scale output kind of accident. Whoops. Loudest 1KHz EVAR! Scared the you-know-what out of me and that made it take even longer to shut the damn thing back off. By the time I did, there was the thrilling smell of fried Tonex in the air. Need to order a pair of those too.

Have you all seen this thread? Wow, I gotta hear these things. I was very close to doing the Neo10 square arrangement too...

http://www.audiocircle.com/index.php?topic=109918.20

this_is_vv · « **Reply #162 on:** 28 Sep 2012, 09:19 pm »

part of my design i owe you to greg,

someday i would love to have a setup like yours......love the way the speakers came out for you....

also i think you are right i need to do some measurements as some frequencies are killing my ear .....

i need to find something around it....

just love your setup please keep posted if you do anything new.....

studiotech · « **Reply #163 on:** 28 Sep 2012, 11:15 pm »

One item off the list. I got help earlier than expected. The move across the room is complete. The baffles are now only 2ft out from the wall where previously they were 6ft. Hope I can make this work out with the Mondo traps and some other broadband absorbers behind and around them. Don't forget, I am using Bonded Logic directly behind the Neo10 anyways, so mids are more or less cardioid. The closest side wall is now 7-8ft rather than right next to them before. Who says side walls don't matter with dipoles? That's hot steaming BS. If you've ever measured one, you would know that there's still plenty of sound between 45-60 deg off axis which illuminates the side walls. Listening position is now at 8fh rather than 10ft prior, so closer in should be better too.

If this works out, the next step will be to get a slim LCD mounted in front of the window and relocate the rack well off to the right side where the maroon curtain hangs which is back to where it was originally. That big ass rack is great, but causes a nice fat obstruction right between the speakers. IF I get that thing out of there, we might really be on to sonic nirvana. I think I would mount the LCD from wire rope kind of floating from the ceiling. That would look sweet.

The system looks great here, BUT the flow of the whole living room sucks now. Not sure if better sound can win this one out....to be continued.

studiotech · « **Reply #164 on:** 28 Sep 2012, 11:26 pm »

Thanks VV. I am still in awe sitting down, knowing that I completed this damn project. I planned and researched and tested for so long, I thought it might never happen.

Is it your desktop design that's hurting your ears? You know, the neo8 sounds great, but you gotta tame the rise in response towards the top end. If you do nothing, it is quite bright sounding. Let's continue this on your thread.

See here:

http://www.parts-express.com/pdf/264-712s.pdf

Greg

bill13 · « **Reply #165 on:** 29 Sep 2012, 06:57 pm »

Thanks for all your interesting postings.

Wish I had more time and $ to work on experimental open-baffle designs using horizontally mounted Neo10s -- and to frequently post here. Thanks for the good suggestion, but don't know yet if my doing infrequent postings would justify starting a new AudioCircle thread

..

Miscellaneous comments:
Anyway, since I don't need much horizontal dispersion at listening distance at 2+ meters, maybe horizontal Neo10s may be way to go? If $ would permit, four Neo10s for less distortion and maybe go a bit lower in frequency.
Also mount RAAL ribbons horizontally and rely on the supplied foam covers to get reasonable horizontal coverage (lobbing)...

I wonder what low frequency cutoff Dan Richie choose for the group of four horizontally mounted Neo10s in his new speaker (understood to be a high pass RC filter at shallow 6 dB/oct)? My measurements so far indicate Neo10s are best employed above roughly 275 - 325 Hz.
I feel that the RAAL is 'better sounding’ than the Neo3 (IMO, the RAAL 14-15D with amorphous core is the 'best' I've heard yet).

BTW I mounted a TC Sounds Pro 5100 18" Neo Subwoofer Driver on a 2' X 2' piece of plywood. The measured response at my usual 2+ meter couch listening location was surprisingly good - far better than the B&C 15" woofer! The 18" especially had far less distortion especially below 300 Hz, and the frequency response plot was smoother up to 300+ Hz (sorry, no pictures yet to post here). The TC Sounds 18" required much less EQ. IMO the 18” is not recommended for use below 50 or 60 Hz because my immediately behind-couch Velodyne DD-15 is preferred (again IMO because at very low frequencies a servo-controlled sub sounds good, and has measurably lower distortion).

Again, I don't know yet whether these measurements of the 18" Vs. the 15" indicate that the 18" woofer would subjectively 'sound' better than the 15" woofer. So far, it appears that the 18" should be OK as long as a steep low-pass crossover (say, 24 dB per octave slope) is used for below the 300 Hz area.

Dan Richie's glowing description of his new speaker that uses four Neo 10s per side tempts me to go to four horizontally mounted Neo10s -- Maybe a much simpler baffle would suffice (I'm not a sophisticated wood-worker, etc. - also, would probably use RAAL ribbon instead of the Neo3. The OB servo-controlled 8" woofer pairs are 'unobtainium' for me.

Maybe someday can investigate refinements like baffle bracing and/or Linkwitz-style rear mounting of the woofers (acoustic decoupling from baffle board), etc.

Gotta run for now,

Bill

studiotech · « **Reply #166 on:** 29 Sep 2012, 07:20 pm »

Thanks for the info, Bill. Maybe once you have a subjective opinion too, you might stop by the thread over at DIYAudio too to offer SilentScreamer your thoughts. I already copied the relevant info from your last post over there. Hope you don't mind... He needs direct advice from people using these parts. At this point, he's got more $$$ and excitement than knowledge about what he's doing to end up with a good result, but he's learning and trying to get it together.

http://www.diyaudio.com/forums/multi-way/215994-first-time-ob-builder-24.html#post3183962

Tyson · « **Reply #167 on:** 29 Sep 2012, 07:51 pm »

Quote from: bill13 on 29 Sep 2012, 06:57 pm

Thanks for all your interesting postings.

Wish I had more time and $ to work on experimental open-baffle designs using horizontally mounted Neo10s -- and to frequently post here. Thanks for the good suggestion, but don't know yet if my doing infrequent postings would justify starting a new AudioCircle thread ..

Miscellaneous comments:
Anyway, since I don't need much horizontal dispersion at listening distance at 2+ meters, maybe horizontal Neo10s may be way to go? If $ would permit, four Neo10s for less distortion and maybe go a bit lower in frequency.
Also mount RAAL ribbons horizontally and rely on the supplied foam covers to get reasonable horizontal coverage (lobbing)...

I wonder what low frequency cutoff Dan Richie choose for the group of four horizontally mounted Neo10s in his new speaker (understood to be a high pass RC filter at shallow 6 dB/oct)? My measurements so far indicate Neo10s are best employed above roughly 275 - 325 Hz.
I feel that the RAAL is 'better sounding’ than the Neo3 (IMO, the RAAL 14-15D with amorphous core is the 'best' I've heard yet).

BTW I mounted a TC Sounds Pro 5100 18" Neo Subwoofer Driver on a 2' X 2' piece of plywood. The measured response at my usual 2+ meter couch listening location was surprisingly good - far better than the B&C 15" woofer! The 18" especially had far less distortion especially below 300 Hz, and the frequency response plot was smoother up to 300+ Hz (sorry, no pictures yet to post here). The TC Sounds 18" required much less EQ. IMO the 18” is not recommended for use below 50 or 60 Hz because my immediately behind-couch Velodyne DD-15 is preferred (again IMO because at very low frequencies a servo-controlled sub sounds good, and has measurably lower distortion).

Again, I don't know yet whether these measurements of the 18" Vs. the 15" indicate that the 18" woofer would subjectively 'sound' better than the 15" woofer. So far, it appears that the 18" should be OK as long as a steep low-pass crossover (say, 24 dB per octave slope) is used for below the 300 Hz area.

Dan Richie's glowing description of his new speaker that uses four Neo 10s per side tempts me to go to four horizontally mounted Neo10s -- Maybe a much simpler baffle would suffice (I'm not a sophisticated wood-worker, etc. - also, would probably use RAAL ribbon instead of the Neo3. The OB servo-controlled 8" woofer pairs are 'unobtainium' for me.

Maybe someday can investigate refinements like baffle bracing and/or Linkwitz-style rear mounting of the woofers (acoustic decoupling from baffle board), etc.

Gotta run for now,

Bill

There is no replacement for displacement. They say that mainly for bass, but IMO it applies very much to mids also. Going with 4 of the Neo 10's gets you a lot lower distortion, and much more transparency and "jump factor" at all dynamic levels. The horizontal mounting is interesting and clever, but you will need a tweeter that can go fairly low to match the crossover point needed for a driver that is essentially 10" wide.

Another option would be to mount the Neo 10's vertically, like a line source, and put the tweeter in the middle of them. Sort of what VMPS does with the RM40 speakers. Now, you still get the same improvements that the 4 neo10's give you, but the driver is now essentially 4 inches wide, so you can use a higher crossover point to your tweeter and still have the dispersion characteristics match up.

Is that better? Depends on who you ask, I suppose. There is one school of thought that says have as wide and as even a dispersion as possible. In this case, the RM40 copy would give you that. There is a 2nd school of thought that says having a narrow (and even) dispersion is better. Like Geddes and GR Research - you use a big midrange driver that beams, and then put your tweeter in some sort of waveguide to make it beam in roughly the same manner.

I've heard both and when well executed they will both sound excellent. The only place that you can really, really screw things up is if you try to mix the 2 together - ie, a big midrange that beams and a tweeter without a waveguide. Or on the other hand, a really narrow midrange with a very beamy tweeter in a waveguide. Those combo's would almost certainly sound bad due to the mismatch in dispersion characteristics, and the resultant disparity in power response in room.

BPT · « **Reply #168 on:** 29 Sep 2012, 07:57 pm »

How about a Neo10 above and below the tweeter, plus a Neo10 on each side. Best of Both?
Chris H.

studiotech · « **Reply #169 on:** 29 Sep 2012, 08:21 pm »

Quote from: BPT on 29 Sep 2012, 07:57 pm

How about a Neo10 above and below the tweeter, plus a Neo10 on each side. Best of Both?
Chris H.

I considered this too. I got lazy and didn't want to buy more Neo10. IF the Neo8-S had been out at the time, I'm sure I would have tried it. Kind of ends up like a virtual coaxial.

Tyson · « **Reply #170 on:** 29 Sep 2012, 08:23 pm »

4 in a circle might be interesting, like you say a virtual coax. I'd definitely recommend using a waveguide on the tweeter in that case.

studiotech · « **Reply #171 on:** 1 Oct 2012, 01:18 am »

Tyson, are you going to RMAF? Please report back about the new model Danny is showing. Thx.

Greg

Tyson · « **Reply #172 on:** 1 Oct 2012, 03:01 am »

Oh yeah, I intend to hit the GR Research room at least twice. It'll all be in my (and Pez's) show reports, updated live, in real time, during RMAF.

Rclark · « **Reply #173 on:** 1 Oct 2012, 03:09 am »

Hey StudioTech, if I wanted to have someone build this speaker based on your design, how much could I expect to pay for all parts?

Ric Schultz · « **Reply #174 on:** 1 Oct 2012, 05:28 am »

Another option is full line sources: 2 neo 10s with 6 neo 3s, 4 neo 10s with 12 neo 3s, 6 neo 10s with 16 neo 3s. My sense is that having a lot of neo 3s will lower distortion and make them more subtle and airy, possibly giving you that Raal detail but with way more dynamics. Of course, you can do a line source of Raals but now we are talking really big bucks.

studiotech · « **Reply #175 on:** 2 Oct 2012, 01:36 am »

Quote from: Rclark on 1 Oct 2012, 03:09 am

Hey StudioTech, if I wanted to have someone build this speaker based on your design, how much could I expect to pay for all parts?

Check your PM.

bill13 · « **Reply #176 on:** 2 Oct 2012, 04:52 pm »

Saw the exciting review of Dan Richie's new OB speaker that uses his 10" square D'appolito' (?) mounting of four Neo10s ... by 'sl_1800' in Audio Circle, Topic: ‘RMAF new stuff, new stuff’.
‘sl_1800’ reported that he could walk around the exhibit room and still hear solid imaging – despite the 10” square D'appolito style horizontal placement of four Neo10s.

Because of this review, I no longer can resist temptation. Therefore am starting a new experimental OB speaker design using horizontal drivers.. However, will first evaluate my previously mentioned experimental three-Neo10 OB for comparison.

This review said: "Sweet spot was as wide as the house, really, I have never been able to move around a room and hear image placement that good" ... ‘sl_1800’ seems very well qualified to compare speakers, because he has heard many top world-class speakers, including Soundlab electrostats (which I also owned many years ago), etc... therefore, I take what he has to say seriously.

Looks like will have to order another pair of Neo10 (accumulate a total of eight each to build an experimental version of the square four-Neo10 OB - but using a much-simplified baffle, & substituting horizontally mounted amorphous-core RAAL ribbons (with foam pads) instead of the Neo3 tweeters. Have not been a fan of the Neo3 tweeters – but evidently, Dan R. modifies his Neo3 driver for more efficiency, etc..

Also will stick with 15” or 18” OB woofers up to around 300Hz.
of course, must use the foam pads on the horizontally mounted RAAL in a shallow felt horn/waveguide to attempt to get an acceptable horizontal radiation pattern.

At soft to medium volume levels, I feel that RAALs can go as low as 1600 Hz. This opinion is based on my experience from another DIY experiment: 1600 Hz 4th order HP filter for my second pair of amorphous RAALs that are currently used in my much-modified prototype Audience '16+16' A3 line array, HP at 1600 Hz.
IMO, at my usual soft volume levels the low 1.6 kHz HP xover sounds better than at 2.5 kHz or higher, because despite occasional distortion at higher volumes, the sound is more engaging, transparent & 'euphonic', with better sound-staging, etc. The RAALs on my A3 arrays uses slight felt-"horn/waveguide" loading for lower the distortion near the HP xover frequency). However, will also try higher xover for the RAALs, say, 2.5 kHz at 24 dB/oct, to see what happens.

Note: the AudioExcite web site's RAAL polar radiation measurements (with the foam covers) look encouraging.
Maybe horizontal lobing won’t be bothersome since my 2+ meter couch listening location is rather narrow/fixed. We’ll see. If anyone in this thread is interested & feels it’s appropriate, maybe I can post a photo of my modified ‘16+16’ A3 array with its center-mounted Raal ribbon in what could be considered a mild felt-waveguide arrangement (hesitate to post because, no doubt, some would consider me ‘nuts’ to do such a (somewhat sloppy workmanship, but sounds very good) mod on a 16+16 line array).

Bill

JeffB · « **Reply #177 on:** 2 Oct 2012, 08:35 pm »

That is a really beautiful baffle.
I am curious about the CNC work. Did you create the computer layout for the CNC machine or did you just explain to the technician what you wanted, and then he created the computer layout?
If you did it, what software was used?

studiotech · « **Reply #178 on:** 2 Oct 2012, 09:58 pm »

Bill, you teased us with the first description, but now you MUST take picts of the new design and make a thread, OK?

studiotech · « **Reply #179 on:** 2 Oct 2012, 10:00 pm »

Quote from: JeffB on 2 Oct 2012, 08:35 pm

That is a really beautiful baffle.
I am curious about the CNC work. Did you create the computer layout for the CNC machine or did you just explain to the technician what you wanted, and then he created the computer layout?
If you did it, what software was used?

Thank you! I drew it all out including dimensions of depth needed for the recesses and then sat there while the CNC guy programmed it. We made a test baffle out of simple MDF first before committing to the bamboo. That would have been a big Ooops!