Rudy81 Posted March 23, 2011 Author Share Posted March 23, 2011 The more I look at the plots, the more I'm perplexed with that 14kHz dip. If it was a large flaw in the build, would all the other higher frequencies not be affected as well? I plan on running some more sweeps tomorrow and being more careful with mic placement etc. After all the work, I'd hate to get rid of them because I measured them wrong. Any ideas guys? Quote Link to comment Share on other sites More sharing options...
Guest David H Posted March 24, 2011 Share Posted March 24, 2011 Rudy, the dip at 14k doesn't look real, possibly a reflection. Notice the traces at 15K+ mimic that of the other horn tested. Not sure what is causing the dip, but you might want to try repositining the horn to limit ground reflection. Dave Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 Dave, I will be testing again today to make sure the issue is real. I plan on pointing the horn up, toward the sky, so as to minimize any ground interference and limit the IR window to a short time span. Otherwise, the plot looks very reasonable compared to the CD P. Audio horn. Results to follow Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 24, 2011 Share Posted March 24, 2011 Looks like DrWho is right, and my handywork sucks! After reading his comments I decided not to wait until tomorrow to run the frequency sweeps. The horn I built does fine until you get in the high frequencies. At least the one I tested has a huge drop around 14kHz! I tried all sorts of mic placement and compared the driver response to the Faital Pro mounted on my P. Audio horns. Graphs to follow...what a bummer. I'm not sure the tolerance thing would cause a dip that big. Did you match the flare of the throat to the exit angle of the compression driver? With a circular horn, any tangential reflections get compunded by it being the same in every axis, whereas the rectangular horns don't have the compounding issue. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 24, 2011 Share Posted March 24, 2011 Btw, could you also do measurements of both drivers on each horn while you're at it? Perhaps you won't have the issue with the K69? Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 I plan on running sweeps with both horn types and both drivers. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 I ran tests with the horns pointed skyward and all 3 horns show that 14kHz dip. However, it seems the DIY horns can certainly hold their own against the P. Audio horn with the same driver. Before tossing the DIY project, I'm going to give them a chance and will hook them up to the DBB bass bins and see how they sound. The attached graph is DIY horn number 3 with the HF200 and then the BM-D750 driver. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 Horns 1 and 3 turned out to be almost exactly alike in performance. Number 2 was slightly different than the others, so plan on using that one for the center channel if I keep them. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 All 3 DIY horns....close enough to each other to work in the room. Whether I keep them or not will depend on how they sound in my room as compared to my current P. Audio horns. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 DrWho wanted some off axis plots, so here is my attempt at getting some 30, 60, and 90 degree readings on the same driver/horn combimantion. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 I would appreciate any comments or suggestions from you guys. You're not going to hurt my feelings if you think this was a waste of time. No big deal if it was. I beleive the performance of the round horns is respectable enough to give them a listen for a few days. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2011 Author Share Posted March 24, 2011 I listened to the DIY horns with the HF200 drivers for about an hour. I'm really glad I didn't take an axe to the horns. Based on the 'supposed' performance in the graphs and the 14kHz dip not withstanding, I removed the top hats from my speakers and tried the DIY horns. Right off the bat, these horns have a much larger soundstage than the P. Audio horns. That, was the biggest difference. Imaging was as good and vocals were also as good as the 4525 horns. I had to turn Audyssey off since it was calibrated to run the P. Audio BM-D750 drivers and it was easy to tell just how much Audyssey was boosting the HF region, so I turned it off and made my quasi A/B comparisons with it off. There is just no other way to run the system and send a no-eq signal to the driver. Unfortunately, doing that makes it really difficult to compare the horns since they have different drivers mounted on them and the BM-D750s sound way laid back without HF EQ. What I did take away from this is that the HF200 is a much better sounding driver in HF than the750...by a lot! So far, the DIY project sounds pretty good. I plan on living with them for a while and then going back to the P. Audio horns to see just how different things are then. But, first impression is very positive, particularly noting how large and 'voluminous' the soundstage sounded vs. the 4525 horns. I guess there is hope after all. That 14kHz dip still bugs me and I'm pretty sure it has to do with the horns since the sweep on the 4525 horns did not show that dip. The dip comes up every time, with every one of my DIY horns....don't know why, but it may not be that important since Audyssey should be able to compensate for it if it is a factor in my listening room. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted March 25, 2011 Share Posted March 25, 2011 I'm glad you decided to give them a shot, though I am a bit confused by the dip. Keep the updates coming. The horns look great. Dave Quote Link to comment Share on other sites More sharing options...
jwc Posted March 25, 2011 Share Posted March 25, 2011 DrWho wanted some off axis plots, so here is my attempt at getting some 30, 60, and 90 degree readings on the same driver/horn combimantion. Rudy. When you took the off axis measurements......say the "30 degree one". Did you put the mic of the center axis 15 degrees or 30 degrees for that curve? jc Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 25, 2011 Author Share Posted March 25, 2011 Rudy. When you took the off axis measurements......say the "30 degree one". Did you put the mic of the center axis 15 degrees or 30 degrees for that curve? jc JC, I'm not sure what you mean, but what I did was the following. The horn was on the ground, pointing skyward. Mic was above horn about 3' with the mic pointing at the center of the driver. For the off center, I move the mic around the center of the horn, roughly equidistant from the mouth. I pointed the mic at the center point of the mouth and took the reading. I may be doing that incorrectly, but fortunately I don't do this for a living. Since I am not using a calibrated mic, an anechoic chamber, and questionable techniques, take all my stuff with a grain of salt. For me, however, it gives me a general idea of what is going on. I hope that helps. Rudy Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 25, 2011 Share Posted March 25, 2011 Rudy, I think you have done a wonderful job. I am thinking the midrange section of those graphs look really smooth, so those horns may still work great in a three way. I know that would be an expensive driver for that purpose, but still... Bruce Quote Link to comment Share on other sites More sharing options...
Guest David H Posted March 25, 2011 Share Posted March 25, 2011 Marvel makes a good point, and looking at the Oris horn site the horn system similar to the horn you built is a 3-way using a coaxial driver. Orphean MkII Compact System The price listed is for one pair including highly modified co-axial BMS 4592ND compression drive units for the mid/high horns, high quality crossovers, and excludes sales tax (i.e. VAT, Mwst., BTW). Luxury painted and polished horns, available in any color desired (plain, metallic and pearl shades). Luxury veneered bass enclosures in either a stained or a natural colour, and finished with transparent lacquer. Inbuilt bass amplifiers with control functions for tuning the Orphean MkII Compact system to your personal preferences. The standard crossover (hard-wired) is built-up with high quality parts such as Duelund carbon/silver resistors, pure silver wiring with cotton in oil isolation and paper in oil capacitors for the tweeter. The price listed is for one pair including highly modified co-axial BMS 4592ND compression drive units for the mid/high horns, high quality crossovers, active bass system and excludes sales tax (i.e. VAT, Mwst., BTW). Quote Link to comment Share on other sites More sharing options...
dkalsi Posted March 25, 2011 Share Posted March 25, 2011 I know I've said this before, but I have heard the Orphean System and I absolutely loved it. Definitely one of the best horn systems I have ever heard. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 25, 2011 Author Share Posted March 25, 2011 The Oris 150, brother to the Orphean II, is one of the best sounding systems I have ever heard. I heard that horn with an 8" driver in a two way setup and was I was blown away by the sound and envelopment of that system. I can always go three way with my current setup, and may try it sometime. I would have to look for a tweeter to compliment the system. My only issue is that I really want to try and stay with a two way setup. Right now, the system sounds pretty good as is. As soon as I get my room put back together, I will run Audyssey Pro and see what it 'hears' in terms of 'in room' acoustics, particularly in the HF area. The calibrated mic and pro processing will make those readings much more reliable than anything I can come up with. More to follow. Quote Link to comment Share on other sites More sharing options...
dkalsi Posted March 25, 2011 Share Posted March 25, 2011 Rudy, I have hear the Oris 150 , Oris 200, and Orphean - my personal preference was the Orphean. In any case, in the event you decide to "toss the horns" away, please make sure you "toss" them in my direction ;-) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.