Hello all. You may have noticed that I've not been posting much or keeping up around here lately. I've had a bit of a health "adventure". I got rushed to the ER early last August, and about a week later was diagnosed with "cholangiocarcinoma", a really bad bile duct cancer (20% survival rate over 5 years ). Finally in October, after lots of preparations and pre-treatments, I went into surgery where the docs were ready and expecting to have to remove part of my liver, pancreas, gall bladder, and gall duct (which was what was blocked). As it turned out, they found no cancer spread at all! They removed the blocked bile duct section and sent it out for biopsy, and it also turned out to be non-cancerous (instead it was some kind of scar tissue buildup). So I don't have cancer after all, and never did! No chemo, or radiation treatment. But I do now have a 13+ inch incision that is taking a while to heal, and my stamina is pretty much crap for now (but getting better). So anyway, I'm back home, no health worries, and will be getting back to work on my Cosyne design as my energy and stamina get better. If you've been following you may remember that I used buyouts for midrange and woofers (and the Aura NS6 woofers went NLA). When I was last working on it, I had made a test unit with FaitalPro 3FE25 as midrange and Visaton W130S-8 for the woofers. Measurements on the three drivers in the horn showed it was all usable, but the needed crossover so far is a little more complicated than the simple linear-phase crossover using the buyouts, and I couldn't get the phase response as linear. But the phase problem seems to be in the tweeter, which hasn't changed. I'm thinking the difference may be the way I did the taper at the throat, drilling through with 1", then using a 30" sanding rod that Ed LaFontaine made for me to try to match the stated 30 degree throat taper of the Celestion CDX1-1445 HF driver. My previous design had a smaller angle at that point (15 degrees, I think), and some filler added to smooth into the rectangular waveguide. So I'm thinking that may be what is making the difference. I'll try to fill and re-machine the throat to see if I can improve things when I get more up and around. If so, I may have a design using long-term available parts. I'd like to do a kit, but not without Tom Danley's permission. Though it did occur to me that DIYSoundGroup could sell kits for the horn (with only the throat opening for the tweeter driver), which would just be a conventional large conical horn. People could use it that way with something like the BA driver, or as a starting point for a DIY synergy design or build, saving a lot of the wood cutting agony. Does that seem like a fair idea? I've also done some work on a crossover design software program that has been in development for a while and that I think everyone will find very interesting. Some designers from here, including Jeff Bagby who created PCD, have been given beta copies, but please don't ask yet -- too hard to manage lots of testers and deal with different versions out "in the wild". Anyway, I should be more active again now. Oh, and sorry for all the grief about the tweeter polarity on some of my designs. I'll blame it on Erich, as he wired the drivers and put them in the test box. (But really, it was my fault. I think I lost track of which measured files I had were inverted or non-inverted). Bill
Welcome back, and congratulations on your new status as a non-cancer survivor. Hope your recovery from the surgery is speedy.
Congratulations Bill! Can wait for your productive return. ;D Say no more! I've been thinking the same thing. Instead of getting more SEOS horns designed & built we could just have a 1" SEOS adapter that can attach to flat-pack horns of whatever size you want. The compression driver interface to the waveguide is a tricky bit that's best left to a molded device.
You must feel that you've been reborn. Wow, what an ordeal. To go from thinking that you're at death's door to a full reprieve, I can't imagine. Good to have you back and may you have a swift recovery from your surgery. ...Roy
Really good news on all accounts. You have been very much missed in these parts and we are glad to have you back, healthy, even at half power you are a machine!
Thanks, Guys. Yeah, it was a really weird experience. I think my wife had it worse than I, as I was rather medicated so didn't fully appreciate the trouble I was in. She had to talk with me every day, keeping up an optimistic appearance without letting on how terrified she was. Until they opened me up, everyone (except maybe me) was convinced I'd be a mess inside and that the end was near. Then, the shock of there not being any cancer at all. It was kind of like winning the lottery (except for that having-lots-of-money part). I still can't walk very far, or even stand up very long, without getting out of breath. And I'm still taking pain meds, so no power tools for me until I get past those. I do want to get out to Erich's soon to see what his warehouse/shop/lab looks like now.
Bill, WELCOME back - what a scary time. My previous neighbor had an almost identical story (blocked bile duct) 6 years ago. Fortunately also with the better outcome that you have described. Good to hear the scary stuff is over and you are healing up. Take it Easy!
I am glad you are doing well Bill, The timing was unfortunate as I had hoped to finally meet you during my stay with Erich but your health is far more important then audio chat
I'm really glad to hear you received the best news possible after going in for the planned surgery. You dodged a major bullet and a miserable death... What a relief. It's nice to have you back and on the road to recovery! 8)
Congratulations Bill. I know the incision is bad, but it's still way better than cancer. Wish you a speedy recovery and happy holidays with family.
Thanks everyone! Yeah, the incision had to happen either way, but is a minor pain compared to what it was expected to be. Bill
Bill, quick question for you. What phase variance do you aim for when simulating the Mids response in a synergy horn? Most of mine come in at around a 90deg variance, some a liitle more. Cheers, Beau
When I'm simulating, I haven't paid attention to phase at all - I do that at crossover design time. Doing a Horn Response sim that is buildable and that goes high enough in freq is already hard enough (I've been going for 2kHz crossover because of the tweeter I've been using). I mostly have just gotten all three bands to work suitably and with enough overlap and then see what I can do with crossovers to get linearish phase. So far I've only gotten the one design that has worked really well, so - I'm no expert at this, there are others who have been at it a lot longer! (besides TD, who obviously is the real expert).
Bill, Have you considered the Dayton CE70-40P-8 "full range" driver in your next design. They are cheap and are a sealed back design. I'm tempted to do a higher WAF version of my speakers with 4 of these, 4 5.25" woofers and another PRV tweeter. I think I can keep the width to under 16" with a 50x50 coverage horn. The weird thing about the wider angles is the size of thing is limited by what you need to miss the woofer magnets. [SIZE=78%]http://www.parts-express.com/dayton-audio-ce70-40p-8-1-5-8-x-2-3-4-full-range-driver--285-121[/SIZE] (Also...super glad to have you back...) Scott
With the passing of JMLC recently, and me dealing with a death and attempted kidnapping in my other half's family... I am so F'ing happy to hear some good news. I won't ever bitch about a flu or cold again after hearing about your health issues! Congrats on the good news. Thanks for making my day... I have been keeping up a little with unity/synergy designs and am happy to see you are back at it! I am going to keep up with your work so I can learn more about crossover design! Here's to an awesome 2014!!!!!!
Tmhutson, Scott, Thanks for the good words. Scott, I've looked at 8inch woofers for this (as a 2-way) but that causes the woofer port holes to be farther from the tweeter throat, so the tweeter has to go down to a lower frequency. I've been hooked on 2kHz crossover because I like that Celestion tweeter, so I'd have to change tweeters. Maybe Erich's new FL driver would do better?
Scratch anything I said about the usefulness of that Dayton driver...it is NOT a closed back design even though the website says it is. I was hoping to use it in a paraline where there is the same problem about getting the 8" driver close enough to the throat. I've got 4 of the Dayton pro 8" woofers arriving today. I'm so hooked on the Synergy sound/concept that I'm giving the paraline another shot, for my garage. Because everyone needs a pair of dual 8"/1" compression driver 90x20 horns in their garage woodworking shop. Scott
I had an idea for a Synergy horn. How about having Autotech make some big 60ºx60º SEOS waveguides, say 20" x 20" out of fiberglass to create a DIY synergy horn? The "horn" is one of the hardest parts about the DIY construction. If we don't drill the mid or midbass holes then they could have plenty of other uses as well. This is the horn I'd like to see come to fruition. We could get Danley's permission possibly if this is a DIY project.
Actually, you could do it legally as long as it doesn't have any of the Synergy-specific features, then it's just big horn. Erich and I talked about getting some rectangular conical horn kits made up (flatpack, mdf), that people could glue up and use any way they wanted. Once you start putting mid or woofer holes on the side pieces, though, the result can't be resold. Of course, the problem as usual is Erich's already knee deep in DIY charity work.
JoshK, What part about the horn construction gets you flustered? I used to be that way...until I built some. I may have some tips to help you out...
Bill, I may have offered this before...but I don't remember. Take a look at the PRV D290, it's a beast and for home use I could push it waaaaay lower and harder than I do. I haven't heard the Celestion, but I did try the Dayton brand compression drivers and gave up on them because of driver to driver variability. I recently purchased the D280's in hopes that they would work on a paraline...but won't because the motor strength is too low. Nice unit to unit consistancy though.
The part where I don't have shop space anymore. ;D Lots of folks have mentioned the difficulty in tolerances with all the angles, especially if you have the secondary conical expansion. Mostly, I really like the idea of really nice fiberglass smooth contour horns rather than wooden square horns. That is mostly a looks thing but the smooth corners of the SEOS profile do have some benefits IMO. Note the SM60F has a smooth profile. On the issue of the Synergy DIY project, I admit I haven't read the patent or tried to really digest what is going on. The part about the Synergy design that I understand the least is the mid and the location to the apex. I know it is suppose to be within 1/4 wavelength of the apex, but I am not sure how you determine where and how this plays into the crossover and preservation of phase throughout. That part is the part I'd like to analyse in isolation for a given target passband. For example, what if I was designing a more traditional midrange horn and rather than placing the driver at the throat, I places it away from the apex as in the Synergy. What happens?