DU73 Posted June 6, 2009 Share Posted June 6, 2009 Very nice - Super work on the cornwalls [Y] Quote Link to comment Share on other sites More sharing options...
Deang Posted June 6, 2009 Share Posted June 6, 2009 I don't impress easily anymore -- but I'm impressed. That barrier strip setup on the outside is slick. Smart design all the way around. Nice job Greg. Forget the 'CornScala' designation. When you get to that level it has nothing in common with the LaScala and the only thing it really has in common with the Corwall is the box volume. Quote Link to comment Share on other sites More sharing options...
Colin Posted June 6, 2009 Share Posted June 6, 2009 Greg Roberts Cornwalls. Sweet. Wonder how frequency response compares to original? Can Greg Roberts Khorns be far behind? Quote Link to comment Share on other sites More sharing options...
aj01 Posted June 6, 2009 Share Posted June 6, 2009 Wow! Is that your wooden horn upgrade (I've looked at your website before) or a shorter one to fit in the cornwall cabinet? I've got a pair of Cornwalls that I bought to restore, but now I have second thoughts... Quote Link to comment Share on other sites More sharing options...
jwc Posted June 6, 2009 Share Posted June 6, 2009 I don't impress easily anymore -- but I'm impressed. That barrier strip setup on the outside is slick. Smart design all the way around. Nice job Greg. Forget the 'CornScala' designation. When you get to that level it has nothing in common with the LaScala and the only thing it really has in common with the Corwall is the box volume. I'm trying to get him to call it anything except using the word "cornwall" so that he could build his own and sell them. Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2009 Author Share Posted June 7, 2009 Wow! Is that your wooden horn upgrade (I've looked at your website before) or a shorter one to fit in the cornwall cabinet? I've got a pair of Cornwalls that I bought to restore, but now I have second thoughts... It's a smaller horn made to be crossed over at 600Hz. Greg Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2009 Author Share Posted June 7, 2009 I don't impress easily anymore -- but I'm impressed. That barrier strip setup on the outside is slick. Smart design all the way around. Nice job Greg. Forget the 'CornScala' designation. When you get to that level it has nothing in common with the LaScala and the only thing it really has in common with the Corwall is the box volume. I'm trying to get him to call it anything except using the word "cornwall" so that he could build his own and sell them. I think it would just be confusing to call it a Cornscala. I think I can come up with another name. But before I start building speakers to sell, I think I ought to get set up to test speakers. After I clear my shop of the ten projects staring me in the face, I am going to figure out what I want to use for testing speakers. Greg Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2009 Author Share Posted June 7, 2009 I don't impress easily anymore -- but I'm impressed. That barrier strip setup on the outside is slick. Smart design all the way around. Nice job Greg. Thanks Dean, that means a lot coming from you. Greg Quote Link to comment Share on other sites More sharing options...
Guest David H Posted June 7, 2009 Share Posted June 7, 2009 I think it would just be confusing to call it a Cornscala. I think I can come up with another name. You could call it the "Osprey" means bird of prey, but sounds good, maybe you should incorporate the V into the name to represent the V-Trac horn. "Osprey-V " Just thinking out loud. May require a little tweaking, but I have no doubt it will sound great. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted June 7, 2009 Share Posted June 7, 2009 Here is another great name. "Cornucopia" (Latin: Cornu Copiae) is a symbol of food and abundance dating back to the 5th century BC, also referred to as horn of plenty, Horn of Amalthea, and harvest cone. Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted June 7, 2009 Share Posted June 7, 2009 Can you also build me the perfect house (room) to put them in? Quote Link to comment Share on other sites More sharing options...
Guest David H Posted June 7, 2009 Share Posted June 7, 2009 Got a couple more: Plangent the condition or quality of producing a deep or loud sound. — plangent, adj. VTRAC - Fanfare VTrac - Salute VTrac - Euphony VTrac - Oxyphony Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2009 Author Share Posted June 7, 2009 Good stuff Dave, keep em coming. Greg Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2009 Author Share Posted June 7, 2009 The first listen didn't go so well, but I'm too tired to try and figure out what's going on right now. I suspect it's a combination of things. I'm going to move them out of my listening room tomorrow and into the larger shop so I can hear the speakers without as much room interaction. Problems with the bass and upper mids. I'm thinking of four things right now - my listening room, which has a wicked low-end grunt to it that is unnatural, the Mark III amps, which I've tried before on Cornwalls and found the whole sound to be flabby in the bass, I wonder if things need to break in, and I'm wondering if I screwed up the crossover build somehow. The mids sound really nice at low volume when I get right up to them, just like when I do the same thing with my Khorns. When I put my ear next to the woofer it's like I'm hearing too much midrange coming from the woofer and no bass. But then back at my seating position is all this really low bass. Upper mids are too low, or there's too much low-mid. I don't know, I'm just rambling now. I'll try again tomorrow. Greg Quote Link to comment Share on other sites More sharing options...
Guest David H Posted June 8, 2009 Share Posted June 8, 2009 I'll try again tomorrow. Good plan, double check everything, run them in the shop a bit to break in , them give them another good listen. I am working on a project as well, I am going to send you pm for your input. Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 9, 2009 Author Share Posted June 9, 2009 I moved them out to the bigger part of my shop and hooked them up to a MC2205 instead of the Mark III's. I took the backs off and double checked all my connections to make sure everything was in phase and that there wasn't anything obvious. I emailed Bob and Al to find out more about the 3636 autotransformers that I'm using in the crossovers, and I found out one major mistake that I was making. I was using the midrange attenuation tap chart from the ALK Universal network, which uses a 3619 autotransformer, thinking that the tap settings would be the same. But that's not the case, the 3636 uses entirely different tap settings. So the 0-2 setting that I was using for the midrange isn't even an option with the 3636, so who knows what that was doing. So now they are sounding much better. I spent a little time balancing the output levels of the drivers and the sound was starting to come around. Right now they're getting a "repeat" CD workout with about 50 watts of power to break them in. More to come. Greg Quote Link to comment Share on other sites More sharing options...
djk Posted June 11, 2009 Share Posted June 11, 2009 http://profesional.beyma.com/ingles/pdf/CP09.pdf Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 11, 2009 Author Share Posted June 11, 2009 http://profesional.beyma.com/ingles/pdf/CP09.pdf That's one of the tweeters I'm testing. Up on top I've got K77, Ciare 1.26ND TW, Beyma CP09. Greg Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 11, 2009 Share Posted June 11, 2009 Greg, I'm pretty sure your Beyma CP-09 is mounted wrong. The "cheeks" should be the other way with the "Slot" in the throat vertical. It is a constant directivity tweeter and also needs to be equalized. It will not work correctly when connected directly to the tweeter output of the network. Al K. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted June 11, 2009 Share Posted June 11, 2009 Here's the frequency plot of the Beyma CP09. Notice the virtually straight line roll off above about 6 KHz. The red line is the EQ I would use for a speaker having nearly 100 dB sensitivity. The blue line is my "Heresy on steroids" den speaker. It's about 90 dB sensitivity (ROUHLY!). You can EQ with a passive network up as high as where it's sensitivity crosses that of the rest of the speaker. For mine at 90 dB, that is all the way to 20 Khz. The EQ I used is shown below. For a more sensitive speaker, like the Cornwall woofer, you can't EQ quite as high before the response nose-dives. It still looks like well beyond 15 Khz. Can you hear anything up that high? I can't! My EQ should be modified slightly for this modified Cornwall but I suggest trying it like it is to give the CP09 a fair shake in the contest between the three tweeters. Getting the correct values for the EQ will take some hair-pulling! Al k. OOPS-- 90 dB marked on the plot should be 95 dB. Quote Link to comment Share on other sites More sharing options...
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