That's the reflection I'm talking about:
An externally hosted image should be here but it was not working when we last tested it.
A strong ipsilateral reflection from 47°. The farther the side wall is away the bigger the angle becomes. Same effect when the toe-in is reduced.
By the way, why did he place the speakers at 35°?
Why not use additional channels and let the recording decide?
Me too 🙂
First, have you looked at its measurements vs Geddes vs all other waveguides? Im not sure what sharp angles you are talking about, there isnt any diffraction issues at the mouth either like other choices.
2nd There are atleast five recent builds with it...Including Zilch, myself, Augerpro, Fb
AE TD15X + B&C DE500 + QSC Waveguide questions & build thread - AVS Forum
High power two way speaker build using QSC waveguides - AVS Forum
TD15M-A, BMS4550, QSC Horn - Build thread with questions - AVS Forum
http://www.avsforum.com/avs-vb/showthread.php?t=1228595&highlight=
Augerpro did tons of work with waveguide,CD and woofer meaurements (which commented was incomplete, He wasn't getting paid to do it 😉 I welcome you to create a set of measurements with the level of details Brandon has)
HTGuide Forum - Can you smell what Brando's cooking!?
5 buids alone here....THanks Zilch and Pete!!! http://techtalk.parts-express.com/showthread.php?t=215536
and more to come, I have shipped off 10 pairs to other countries to people don't know at all just so they can have the benefits of not spending hundreds on a waveguide.
If you are building DIY then what other options are there? 18sound has some nice horns but > $100 each and not much difference in the measurements. You can simply buy Geddes Summas or Abbeys if you think others suck.
Last edited:
Again, those measurements showed the issue at 45 deg (IMO) and if you notched 45deg you would have solved 90deg. I also commented that the woofer would maybe be XOed lower and that 90deg issue may not even exist. As for "time will tell" comment. I buy better drivers 😉
Do you have your DIY build so I can follow it?
"Cheap as possible" isn't always great because sometimes best SQ isnt cheap.
I have many cheap CDs. The B&C DE150 is what Augerpro used for his lowcost solution (I think), Zilch used the D220Ti for his standard build and I liked the the Celestion 1745 (sold on QSC's online part ordering site).
I have the Celestion 1425, Selenium D220. I also have the BMS4550 and just ordered the Radian 475 so I have many to listen too.
What CD and speakers do you own?
Last edited:
Precisely my take on the situation as well, but in private discussions with him he clearly leans towards "more spaciousness" than "better imaging".
As I said before, when I say 90° waveguide, I mean the physical wall angles NOT the far field response. A 90° waveguide will tend towards 60-70° at 6 dB down as my data clearly shows. "moderate" / "Narrow" is not the issue, its "control". When you do not look carefully at directivity its not going to come out well.
This is where I have a serious issue with Linkwitz - he always draws those nice dipole lobes, but his systems are no where near that well controlled across the bandwidth. Its wishful thinking.
Last edited:
My own experience says 4" thick OC703 on the wall behind the speakers is gold in terms of SQ improvements.
All custom HT room designers treat the front wall behind the speakers add CD speakers like yours Geddes and someone has an incredible room full of sound.
Correct the 1745 is in the HPR152 and the 1425 is in the HPR122i.
They are BOTH 1" CDs though.
😀Well, how about using multiple oval listening room concept? Design for two ovals where two ears are at two focal points, and the speakers at two other focal points?😎
Huh? His 'critical listening' setup has the speakers 6' from the front wall so that's ~12ms.
There's no question that dipoles have better directivity control than monopoles below the XO frequency so the only way waveguides really make sense to me is to build them into the room corners so the walls act as a waveguide for the mid-low frequencies.
And I think it's doing SL a disservice to claim he's going for artificial spaciousness or sound effects. His standard has always been trying to match what he hears in a live concert. He makes his own recordings with tiny stereo mics taped to his eyeglasses right by his ears and then goes home and plays it back to hear how similar it sounds.
Last edited:
I'm sorry, but this comment doesn't make sense to me. "Below the XO frequency" (and I have to assume that you mean 500-800 Hz or so) directivity isn't very important so having "better control" is kind of a mute point. But being precise, a "monopole" has perfect directivity control, its pistons that don't (but I think that this is what you meant). For me the piston has the "better" "directivity control" in that it does just what I want - it narrows down to match the waveguide at the crossover. Dipoles don't do this (well they could be made to, but most are not), there is still a change in directivity at the crossover, unless its very low, in which case it kind of also makes your point mute.
I don't know where people get the idea that OB speakers don't have changing directivity because they do. It's not as extreme as a closed box at LF, but its the same at HF. So where it matters the two are the same.
Not all the other WGs. No one I know has. But yes I've seen its measurements and it looks intriguing.
I can **** further than any man.🙄 I commend Brandon's work. There the best around that I know of.
Huh? Not sure what you mean by this and I don't see any relevance to the thread.
Why do you want to assume what I mean? Odd.
Dan
There have been several threads here and elsewhere focusing on keeping OB baffles very narrow (under a wavelength in the passband) and people are achieving pretty good CD over a surprisingly large range, say from 80-10K, running naked drivers with no baffle. Once the baffle width gets over a wavelength, piston diameter becomes controlling.
To me, one of the best tests of power response is the 'down the hall' test. If you're outside the room and it sounds like there are live musicians in the room, you've got it right however you get there -- waveguides, dipoles, whatever.
You posted an early opinion about the QSCs so Im posting all the info I have.
The point is that its a great waveguide based on the measurements and its costs $12. QSC parts division is actually a little caught off guard and they go back order all the time. Currently its late June before anyone can buy them. I have had a discussion with QSC over this and they may stop selling them to DIYers.
Im not assuming anything from you. I have no idea what you own or what you are building. Im just asking to find out.
If you have certain waveguides then it would be great that you posted them for others to learn about.
Yea, If you can't see those issues, I can't help you. I can state it more specifically as I believe that you can understand something as glaringly obvious. Look at the 45 then the 78.75, 67.5, 90, 56.25, which ever you want. It is obvious. Ask Zilch or Wintermute--they got it first view. 😉
Nothing live. My best contribution to the DIY community: - Techtalk at Parts-Express.com
Nothing new under that sun. 90 percent of that info is here except the polars on the PE WG. I haven't put them in their final boxes so no pretty pictures. Of course that's assuming my pictures would be pretty.
Selenium D220--got'er on sale knowing Zilch used it. I had an ASD1001 before. They are too cheap--not financially. You can never have too cheap a cost. The Selenium D220 are the "cheap as possible" option for me. I'm sure I haven't seen them all. I don't regret buying them as they do what I need. Didn't see the BMS prior so maybe they'd have been better and similarly priced. Here's its polars on top of speaker in the 10"PE WG:
I'd prefer to keep this thread about measuring drivers, what and why instead of "what drivers do you have?" ******* contest, chest pounding type of thread. There's too much of that stuff around and it only holds learning back. I'm more interesting in sharing what I know and what you know so we all can learn.
It will be interesting when I get these in their final boxes and see how they then measure then. That will be a learning experience for me.
Dan
No ******* match at all with me. I just will ask lots of questions. Im curious about the need to focus on 90degress. You are right about it so no need to discuss it more.
Your comment about QSC
Is definitely paranoia since is a far better waveguide then the PE 10" round waveguide and its screw on throat. You should have found the QSC HPR-122i 10" round waveguide, its also better (bolt on always will be better then the long throats of the screw on choices). I have compared them all. The D220/10" PE wasn't very good SQ wise but maybe EQing helps that. I didnt do much with each of them.
Your comment about QSC
Is definitely paranoia since is a far better waveguide then the PE 10" round waveguide and its screw on throat. You should have found the QSC HPR-122i 10" round waveguide, its also better (bolt on always will be better then the long throats of the screw on choices). I have compared them all. The D220/10" PE wasn't very good SQ wise but maybe EQing helps that. I didnt do much with each of them.
Last edited:
When you say far better, I want proof. You've seen the 10PE WG/Selenium. Will you post some measurements? This 10" is part of the best speaker I've ever heard--the best part. I don't doubt for a second that there are better-- I was sure of that when I bought it. You can see what I think are those throat problems in the response. Frankly I was shocked at how good it sounds. Crossover/polar response has a lot to do with what's heard, as we well know, and I've got these done pretty well. Just another look to save time:
I don't like the screw on throat either, but the price of admission was right. I do like the looks of that HPR-122i ($6.55 to boot!), but I'd have to see something that would make me believe it's worth it to change. The price of the CDs is the problem. The QSC site doesn't help--not that I expected it to. Manufacturers. 🙁
BTW, I actually think a 90 degree WG would be better for the crossover/break up problem. That's what I like about the Geddes WGs. I know I have a paranoia about non round horns d/t prior auditory experience. I'd sure like to hear some that didn't hurt my ears. These PEs do not, but my suspicion is that it's more about the crossover and the response out to 90 degrees than anything. This:
This:
Dan
Oh, it might be interesting to see those QSCs w/ bolt on Seleniums vs the PE w/ screw ons. Hopefully someone has them.
Dan
Dan
Brandon / augerpro has measured the QSC waveguides, albeit with B&C drivers. He has horizontal as well as vertical polars. Not out to 90 degrees like you've asked for though. I think he goes out to 60.
Frequency Response w/ B&C DE250 (drivervault)
Regarding bolt-on vs. threaded - I have a tiny bit of experience here, where I tried a Selenium adapter to put a bolt-on driver onto a threaded horn, or was it the other way round. The response was pretty bad, and I could see that the threaded part of it didn't mate right, there was a gap between the end of the driver and the next surface. Filling that region with foam helped with the 12-14kHz null that I had, but didn't eliminate it. Switching to a bolt-on driver and WG took care of it.
Frequency Response w/ B&C DE250 (drivervault)
Regarding bolt-on vs. threaded - I have a tiny bit of experience here, where I tried a Selenium adapter to put a bolt-on driver onto a threaded horn, or was it the other way round. The response was pretty bad, and I could see that the threaded part of it didn't mate right, there was a gap between the end of the driver and the next surface. Filling that region with foam helped with the 12-14kHz null that I had, but didn't eliminate it. Switching to a bolt-on driver and WG took care of it.
Yeah, thats the Emerald Physics speakers, right? It does show that XOs/woofers mean a ton to the design. I did say that I did not EQ much just played around with how the each horn sounded. I did post I have the Selenium/10PE WG pair sitting in my Garage unused now. I sent them all off to Augerpro for measurements so he has the measurements.
My "Far better" comment is purely my subjective opinion on listening but the CSD shows the D220 has problems (See augerpro's measurements), The D220 was the worst sounding CD of all my CDs.
Im not using my HPR-122i wavguides or the Celestion 1745 or Celestion 1425 CDs. I think the 1745 is better then the 1425. None of them go down to 1KHz though, just in case you are wondering about that.
If you want them to demo. Send me a PM.
Last edited:
The wavelength at 10 kHz is about an inch - even the baffle thickness is significant - no baffle at all might work, but then support is an issue. And then there is the diffraction ... I keep hearing these claims, but supporting evidence is very rare.
- Status
- Not open for further replies.