Greets!
FWIW, I found out on the old basslist that mine and another's experiments had independently arrived at the same conclusion that at least for 511s a combo open/closed cell foam pad wrapped around the horn to create a ~5.25" extension worked best overall. Obviously, a < Zero WAF solution, YMMV, yada-yada: http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=7637&memberId=12500226
GM
FWIW, I found out on the old basslist that mine and another's experiments had independently arrived at the same conclusion that at least for 511s a combo open/closed cell foam pad wrapped around the horn to create a ~5.25" extension worked best overall. Obviously, a < Zero WAF solution, YMMV, yada-yada: http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=7637&memberId=12500226
GM
panomaniac said:
Then what would you suggest? What have you done to your's, or have you, other than what you showed a picture of?
I'm also looking forward to the DCX2496 as well, but it will a little bit before I can buy one. Not too long off, but not right away either. Maybe a month or so.
BTW, I've been playing around with the DCX2496 Remote 1.16a software for the last couple of days and it looks like I still might need the DEQ2496 for the mains. The reason being that once I get all 3 channels (L/C/R) up and running with L-R 48dB xovers, 8ms woofer delay, para-EQ notches around the xover freq's and +10dB of boost of low shelving @ 12dB per octave around 30Hz for the mains and 50Hz for the center (smaller baffle), I'm down to 5% processing left. That 5% is enough to allow me to tweak the center channel a little more if it needs it.
So for the mains, I'll get the DEQ2496. To me, getting the mains as close to perfect as possible is most important to me, and the DEQ2496 is a lot more flexable for that job.
No, no functioning camera and the pads were so rotten/powdery I took them off several years ago when my electronics finally died. Once I get a functioning system I'll head on over to Wal-Mart and get a new one to cut up. I hope they haven't 'improved' them since the mid-'80s when I acquired mine.
Note that in retrospect I wasn't clear enough, I wrapped the entire horn/driver combo out to ~5.25" beyond the lips. Of course since you're satisfied the rest of the assembly is damped well enough, just wrapping the perimeter in front of the mounting flange is all you need do.
Note that in retrospect I wasn't clear enough, I wrapped the entire horn/driver combo out to ~5.25" beyond the lips. Of course since you're satisfied the rest of the assembly is damped well enough, just wrapping the perimeter in front of the mounting flange is all you need do.
Well I hope you get your system back up and running soon. One shouldn't go long without music and a fine system to play it on. 😉
So when you wrapped the foam around the horns, did you cut the sides back some to allow the full horizontal dispersion of the horns, or did you leave that sticking out the full 5.25" as well? I would imaging that leaving the sides out 5.25" would probably help reduce side-wall reflections.
I was also thinking, what about getting some thin felt (0.25" or so) and laying it in the horns from the edge of the lips inward 4-5" or about the depth of the fins on the top, bottom and sides? Do you think that would work? What about the fins themselves, should they also be treated with felt?
So when you wrapped the foam around the horns, did you cut the sides back some to allow the full horizontal dispersion of the horns, or did you leave that sticking out the full 5.25" as well? I would imaging that leaving the sides out 5.25" would probably help reduce side-wall reflections.
I was also thinking, what about getting some thin felt (0.25" or so) and laying it in the horns from the edge of the lips inward 4-5" or about the depth of the fins on the top, bottom and sides? Do you think that would work? What about the fins themselves, should they also be treated with felt?
No, one of the goals was to further reduce early reflections since few horns have a narrow enough horizontal response for a typical room and why 'bear' recommends rotating them 90 deg like is often done with old EV horn tweeters.
Felt that's dense enough to effectively reduce standing waves at the mouth will affect horn response, especially the HF. Some folks remove the vanes altogether and claim it's the 'Hot Ticket', while others hate it. I never tried it since I didn't like EV's similar unit that didn't come with them. Anyway, only one way to know for sure if the felt works for you. The bottom line for me is I don't want any damping material inside the horn.
Felt that's dense enough to effectively reduce standing waves at the mouth will affect horn response, especially the HF. Some folks remove the vanes altogether and claim it's the 'Hot Ticket', while others hate it. I never tried it since I didn't like EV's similar unit that didn't come with them. Anyway, only one way to know for sure if the felt works for you. The bottom line for me is I don't want any damping material inside the horn.
I agree with Greg, you gotta try it and see (hear).
Felt and even sandpaper inside the horn mouth or throat (if it's a big horn) has sounded good to me. Layers of foam or fabric that follow the shape of the horn flare back around to the baffle would be the first approach to try. But you'll probably have to try different things yourself to find what works.
It's certainly not expensive, just tedious.
Have fun with the Behringer stuff, you're very ambitious. I think I might get lost with all that processing! 😀
Felt and even sandpaper inside the horn mouth or throat (if it's a big horn) has sounded good to me. Layers of foam or fabric that follow the shape of the horn flare back around to the baffle would be the first approach to try. But you'll probably have to try different things yourself to find what works.
It's certainly not expensive, just tedious.
Have fun with the Behringer stuff, you're very ambitious. I think I might get lost with all that processing! 😀
One thing that you could try inside the horn mouth is adhesive velcro. Buy a pack and use the "fuzzy" part. If you don't like it, it's at least easy to remove. Tried this myself on a pair of Rat Shack super tweeters using the EnAbl pattern, was surprised at how much it improved them.
I decided to try out that SynRTA software today on my dipoles and this is what I got.
A little about the setup:
This is both channels driven, SPL was about +20dB above the noise floor (about 85dB) at my listening position, the mic used is the Behringer ECM8000 mounted to a sturdy mic stand and boom, the mic preamp is a dbx 760X, and the soundcard is a SoundBlaster Audigy2 Platinum. Pink Noise was provided by my Behringer DEQ1024.
There's a peak popping up around 900Hz. Not sure what that's all about. And there's also a dip around 15kHz. Not sure about that one either.
I'll run a couple more tests in a little while of just the woofers by themselves, then the horns by themselves and see what happens then.
BTW, the EQ was where I set it by ear. Not too shabby I guess, considering.
Red is EQ'ed
Green is not EQ'ed
A little about the setup:
This is both channels driven, SPL was about +20dB above the noise floor (about 85dB) at my listening position, the mic used is the Behringer ECM8000 mounted to a sturdy mic stand and boom, the mic preamp is a dbx 760X, and the soundcard is a SoundBlaster Audigy2 Platinum. Pink Noise was provided by my Behringer DEQ1024.
There's a peak popping up around 900Hz. Not sure what that's all about. And there's also a dip around 15kHz. Not sure about that one either.
I'll run a couple more tests in a little while of just the woofers by themselves, then the horns by themselves and see what happens then.
BTW, the EQ was where I set it by ear. Not too shabby I guess, considering.
Red is EQ'ed
Green is not EQ'ed
Hey Chops - that looks pretty good.
Do remember that synRTA wants its own version of pink noise. You can run it out of the sound card or burn it to CD. It's not quite pure pink. But it seems that your measurements worked well anyway.
I see that you have the same roll off under 100Hz that I have. Wonder is that's the room, the OB, the mic, what?
With all your EQ, I would have thought your roll off would be lower.
Is that 1K peak with or without towels around the horn? Maybe some diffraction damping would kill it.
All in all, looking pretty good for an in room measurement. Mine don't look at all that smooth, yet.
FWIW, measurements are usually done one channel at a time to prevent comb filtering at the mic. Doesn't look like you have much problem there, tho.
Thanks for the measurements!
Do remember that synRTA wants its own version of pink noise. You can run it out of the sound card or burn it to CD. It's not quite pure pink. But it seems that your measurements worked well anyway.
I see that you have the same roll off under 100Hz that I have. Wonder is that's the room, the OB, the mic, what?
With all your EQ, I would have thought your roll off would be lower.
Is that 1K peak with or without towels around the horn? Maybe some diffraction damping would kill it.
All in all, looking pretty good for an in room measurement. Mine don't look at all that smooth, yet.
FWIW, measurements are usually done one channel at a time to prevent comb filtering at the mic. Doesn't look like you have much problem there, tho.
Thanks for the measurements!
Hey Panomaniac. Here's the last run I did with SynRTA's own pink noise and a litle bit more tweaking of the EQ. I think this one looks much better, and seems to "look" the way it sounds for the most part.
And this is what the EQ looks like now...
1) Tuned by ear...
2) Tuned with RTA...
And this is what the EQ looks like now...
1) Tuned by ear...
2) Tuned with RTA...
Looking Good!
So which do you prefer, the by ear or the by measurement EQ?
I can never get a curve that smooth, especially in the low end. The only way my graphs come out nice is to put the mic right in front of the driver. Must be room noise here. (Windows and doors open 24/7). Or maybe I need to test at a higher SPL. At what SPL do you test, do you know?
Another question. How far from the speakers is your listening position? I was just thinking that you might not want so much top end boost. There should be a natural high end roll off as you get farther and farther back. That was covered nicely in the thread Why "Flat" is Inaccurate back over the summer. Some good reading there.
So which do you prefer, the by ear or the by measurement EQ?
I can never get a curve that smooth, especially in the low end. The only way my graphs come out nice is to put the mic right in front of the driver. Must be room noise here. (Windows and doors open 24/7). Or maybe I need to test at a higher SPL. At what SPL do you test, do you know?
Another question. How far from the speakers is your listening position? I was just thinking that you might not want so much top end boost. There should be a natural high end roll off as you get farther and farther back. That was covered nicely in the thread Why "Flat" is Inaccurate back over the summer. Some good reading there.
panomaniac said:
Thanks!
Actually, the measured EQ does sound better, as it should. I got to see roughly where that slight honkiness was coming from and was able to completely eliminate it. Plus there were a few things bothering me a bit in the mid-bass and mid-treble that I couldn't exactly put my finger on. I pretty much have those ironed out as well now using SynRTA. I always run my tests at 85dB which is about 40dB over the noise floor (between 42-47dB).
My listening position is 12' away. The reason I have so much top-end boost is because the Altec 902-8B drivers diaphrams are work hardened from years of use in a large movie theater in Atlanta, GA. They were used in that setting for over 20 years, so needless to say, they are a little tired these days. But that's why I need that kind of boost. 😉
I was suggested by someone on another forum that I should try lowering the xover freq back down to 900Hz since the 15HM drivers start to have some 2nd and 3rd harmonic distorsion activity at and above this range. I think it sounds a little better. When I get the time, I'll run a few more tests on them with SynRTA to see what shows up.
Also, I forgot to mention before, but these Usher drivers were tested by the factory as being 97dB efficient, not 95dB as in the specs. In fact, they are 97, 97, 97.4 and 96.4dB each. When I mounted them to the baffles, I paired up both 97dB drivers together and paired the 97.4 and 96.4dB drivers together to keep them as close as possible. I'm sure this also makes sense as to why these speakers are so much more efficient than I had originally expected.
And one more thing, I still can't get over how deep and punchy these drivers are on OBs. I never expected to be playing these speakers fullrange, but since they sound so darn good on their own, I never have my subwoofer on anymore, except for movies. Even durring movies, I have still keep them playing fullrange, just that I throw the sub in there as well for the LFE. The amazing this is, this bass is always there, even at low volumes. It's very tight, detailed, uncolored and natural.
The Klipsch Cornwalls never had bass this deep or punchy. In fact, the bass on the Cornwalls was never anything specail to begin with, rather boomy and lacking. I never liked them fullrange. Honestly, I didn't like much about them at all. The only thing they had going for them was their efficiency and the ability to play loud with little power, at the cost of nearly making your ears bleed that is. Hence the reason why I had the Altecs covering everything from 600Hz up.
Yes, I am very happy with these OBs! 😀
Also, I forgot to mention before, but these Usher drivers were tested by the factory as being 97dB efficient, not 95dB as in the specs. In fact, they are 97, 97, 97.4 and 96.4dB each. When I mounted them to the baffles, I paired up both 97dB drivers together and paired the 97.4 and 96.4dB drivers together to keep them as close as possible. I'm sure this also makes sense as to why these speakers are so much more efficient than I had originally expected.
And one more thing, I still can't get over how deep and punchy these drivers are on OBs. I never expected to be playing these speakers fullrange, but since they sound so darn good on their own, I never have my subwoofer on anymore, except for movies. Even durring movies, I have still keep them playing fullrange, just that I throw the sub in there as well for the LFE. The amazing this is, this bass is always there, even at low volumes. It's very tight, detailed, uncolored and natural.
The Klipsch Cornwalls never had bass this deep or punchy. In fact, the bass on the Cornwalls was never anything specail to begin with, rather boomy and lacking. I never liked them fullrange. Honestly, I didn't like much about them at all. The only thing they had going for them was their efficiency and the ability to play loud with little power, at the cost of nearly making your ears bleed that is. Hence the reason why I had the Altecs covering everything from 600Hz up.
Yes, I am very happy with these OBs! 😀
Thats nice to hear, really ... and the subman himself has gone subbing something else ... well, we may have to think twice now, and maybe means I can save the cost of 16 woofers😀 🙂
Well, we can talk and talk, but you actually built it, so hats off to that ... and I have said it before, but I still think you may have proven something important here
Well, we can talk and talk, but you actually built it, so hats off to that ... and I have said it before, but I still think you may have proven something important here
tinitus said:
The "subman"... "we may have to think twice now, and maybe means I can save the cost of 16 woofers"? Sorry, but you've lost me. 😕
And I'm not too certain what you're referring to about "proving something important here". Please explain when you get the chance.
I still haven't been able to do any testing on the new xover freq. Hopefully I'll be able to do some testing tomorrow after work. We'll see. 😉
tinitus said:
That one has got me puzzled, too. Ha! 😕
Hey Chops - about the FR plot.
I was thinking that your last graph looked kinda hot in the top end. At 1 meter it would be right, but at 12 feet you should be rolling off on the top end a bit more. What you have now should sound a little bright. If you pull down your top end EQ a couple of dB, you might like it better. The highs should fall off with distance - that's what sounds natural.
And maybe the next investment should be a new set of diaphragms for those poor, long suffering Altec drivers. 😉
You've got me tempted to buy one of those DEQ EQs just to play with. I'd like to try it digital in/out. Maybe after Christmas....
Chops ... sorry, but are you not the one advocating very strongly fore 15hz subs in another thread 😉
"What you have proved" ?
Well, fore one I believe in a 3way with bassboost instead of adding subs, maybe because of the better phase behaviour ... and you say you dont need the subs now
It seems with a PA compression driver its possible even with a 2way
And secondly that the kind of woofer in pairs like the Usher will take this bassboost with ease, and still sound good
Obviously no need fore high Qts values or huge Xmax
To me it seems like one of the easiest ways to achieve a high power quality speaker ... no box, not even a big baffle ... nice and simple
But I actually wouldnt rate it as OB/dipole, but more like a CD-Horn with dipole bass😉
"What you have proved" ?
Well, fore one I believe in a 3way with bassboost instead of adding subs, maybe because of the better phase behaviour ... and you say you dont need the subs now
It seems with a PA compression driver its possible even with a 2way
And secondly that the kind of woofer in pairs like the Usher will take this bassboost with ease, and still sound good
Obviously no need fore high Qts values or huge Xmax
To me it seems like one of the easiest ways to achieve a high power quality speaker ... no box, not even a big baffle ... nice and simple
But I actually wouldnt rate it as OB/dipole, but more like a CD-Horn with dipole bass😉
panomaniac said:
Hi Pano,
Tell you what, when I get the mic set up and everything in a few minutes, I'll remeasure at 1 meter like you suggested, just to see how it sounds. If I don't like how it sounds, I can just put it back the way it was and just tweak it some more from there.
Yeah, I do plan on buying some new diaphragms eventually. Maybe sooner rather than later. When I do, I want to remove the loading caps and install those felt pads that GPA sells, along with new, shorter mounting screws. That will probably be $200+ right there, but worth it.
Something else I want to get is a Behringer DSP1124P or FBQ2496 for my sub, but which one? The old one looks like it would be more than enough with 24 para-EQ bands. Is there any reason to go with the new one with 40 para-EQ bands? I only need it from 50Hz on down. Is it worth the extra 50 bucks?
I really like the DEQ1024 I have. It's functional, quiet and gets the job done. You certainly can't beat the price.
tinitus said:
Hmm... True. These OB's do seem to make a few exceptions to the rule. That's why I always like to just go ahead and try some things from time to time. You never know until you try. 😉
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