I built a throat extension to use them in my bass horn and they go to 150 cycles and drop like a brick - same horns with a 15 in the same exact spot i get to 90 cycles with slow rolloff - I am build a big WE style horn for them to use in free space- hoping to get to around 200 with them
thanks for the info! I was playing around with a tractrix calculator and seemed to find the sweet spot in terms of size/LF to be ~160hz horn, or about 28" diameter and 24" deep (to 4" throat)....I just didn't know if the extra LF was usable. StereoLab offers 190hz tractrix horns with 4" throat option, which is enticing.
I can't say I have ever used any of those real exotic compression drivers that work that low. I have used the Emilar EC600 (not in business anymore) that had a 6" dome and 3" exit and once used the Adamson kevlar compression driver - 10" with phase plug - with the TAD 4001. This has been something I've been working on for around 15 years -The JBL CMCD 8" drivers are better than either of those. They have better low mid response (warm and full of tone - i like that) and are less ragged towards the top end (2.2K)
With the 4001 the problem is everybody wants to extract the widest bandwidth out of it (me included) - if you do that you will probably find crossing it below 800 cycles where the horn gets too big to deliver the upper range as well as a separate treble horn. using it 800-1000 up is probably abetter idea with a smaller horn. I used 550 round Edgar tractrix horns with mine and it was delightful - below that was the TAD 1201 in a 100 Hz tractrix - this was crossed at 900 cycles - from 150 cycles up the system was heaven
Thanks very much POOH. I was not planning on running just the TD4001 straight up from its lower crossover point. For example if TD2001 used higher up allows me to use the TD4001 in a larger horn crossed a bit lower, and still sound good, then great. I think the 1201 is still in production, I will look into it. I think what makes my system goals different from others is I only need a system to play well on axis in a dedicated room.
btw, just in case anyone browsing is interested to know where to source the JBL CMCDs, I bought mine off this guy on ebay. He was really nice to deal with and sourced the phase plugs for me and sold those to me as well in a separate transaction, along with the gaskets and shipped it up to me in Toronto. So I'd say he is a good source, but you could try out JBL part services directly if you are so inclined. BTW, I think he has the phase plugs listed now in his store because of my query.
JBL 2169H 8" Woofer for STX 835 | eBay
JBL 2169H 8" Woofer for STX 835 | eBay
Yes it does.
When it comes to recording a performance, close miking is an abomination.
Rock music of all types first and foremost with blues, jazz and popular classical mixed in. A great example of dynamic drums that comes to mind would be A Perfect Circle ' The Hollow' or a new Brittish duo Royal Blood. Big drum sound of classic rock and roll from Ginger Baker, John Bonham' and Bill Ward comes to mind as well.
POOH,
I have had to move some old original WE W-bass bins in my youth, they weighed a ton. We used them for bass reinforcement back then for outdoor concerts, they were used with a bunch of Altec A2's sometimes with the wings. We are talking eons ago and before there was anything like the smaller Eastern Acoustics bass bins. Stuff was bigger back then!
Have you considered a pair of RCA Ubangi's, that was one of my favorite classic horn designs. When my wife was alive there was no way I would have ever had a system as large as you are talking about. Right now I have a pile of molded throat sections for double 18" bass horns that look rather like the RCA's. Sounds like your system would be rocking to say the least.
I have had to move some old original WE W-bass bins in my youth, they weighed a ton. We used them for bass reinforcement back then for outdoor concerts, they were used with a bunch of Altec A2's sometimes with the wings. We are talking eons ago and before there was anything like the smaller Eastern Acoustics bass bins. Stuff was bigger back then!
Have you considered a pair of RCA Ubangi's, that was one of my favorite classic horn designs. When my wife was alive there was no way I would have ever had a system as large as you are talking about. Right now I have a pile of molded throat sections for double 18" bass horns that look rather like the RCA's. Sounds like your system would be rocking to say the least.
I'm actually building a low mid horn with a mouth size like the WE 15a but with a bigger throat for the JBL CMCD drivers. If it works out the next step maybe different bass horns but I doubt I'll do that because I'm out of room.
https://www.youtube.com/watch?v=NLeU1NbfURc
https://www.youtube.com/watch?v=NLeU1NbfURc
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POOH,
That curved horn looks so much like the very first horn I ever built in 1976, you could say they would be twins. My construction on that first horn was a fiberglass flare with inner and outer skins and the shell filled with urethane foam, It had a 75hz 1/4 wave mouth size and a 7 foot path length. To say that made some strong bass would be to put it lightly. I do remember having them in the house for a party, my neighbors at the time weren't to happy about the bass from my house into theirs, didn't like those people anyway!
I also see the W enclosure on that same U-Tube page. That looks like a miniature version of the WE W-bass bins we used in PA so long ago, I think it was about 1971 or '72 when we were doing that.
That curved horn looks so much like the very first horn I ever built in 1976, you could say they would be twins. My construction on that first horn was a fiberglass flare with inner and outer skins and the shell filled with urethane foam, It had a 75hz 1/4 wave mouth size and a 7 foot path length. To say that made some strong bass would be to put it lightly. I do remember having them in the house for a party, my neighbors at the time weren't to happy about the bass from my house into theirs, didn't like those people anyway!
I also see the W enclosure on that same U-Tube page. That looks like a miniature version of the WE W-bass bins we used in PA so long ago, I think it was about 1971 or '72 when we were doing that.
View attachment 455304 if it doesn't work out I need to let the sawdust fly. LOL
The jmlc 200 fiberglass horn looks like a good match for the JBL CMCD. Long delay for ship to USA if you cannot find a loaner to test.
Attachments
These are Emilar designed/built horns to be used with the 6" aluminum compression driver EC600 like I did here. With EC600 when mounted on the floor they went down to where I could successfully use them in the upper bass. With CMCD I expect as good of results but using them above upper mid and treble horns. So I expect to be blown away.
If it does not sound breath taking real (it does now already) then I will build my own low mid horn specifically for my purpose.
If it does not sound breath taking real (it does now already) then I will build my own low mid horn specifically for my purpose.
I already have 180 cycle flare Sierra brooks round wooden tractrix horns, similar to these but IMO better. The Emilar horn is much, much better in the low midrange. It loads the fundamentals in more realistic way and will go quite a bit lower with the right driver. Round horns aren't anything special and I have so many other options then to send somebody money and waitt for more compromises. If this doesn't do what i want i will build my own compromises.
Preliminary on the CMCD in the emilar horn - not so great (thraot mismatch on top and weak on the bottom due to back chamber?)- the little B&C 6pev13 is a much better match - no back chamber free air linear response 150 to 1.2k - on the floor i'm getting response around -3db at 100 with great articulation - time to rethink the whole darn system with the 15" bass horns LOL - I love this stuff
The B&C should probably not be used so close to its Fs =126Hz. However, interesting driver. I wonder how it stacks up to the Fane S 8M. The Fane seems to have its own problems and it would be interesting to do another take on the upper midbass horn.
But POOH, you should get round or oval horns for mids and upper mids. They sound smoother.
I noticed that the JBL CMCD has a very small spider. Maybe this driver is not to be used for midbass at all. And yes, the back chamber is very small.
www.jblpro.com/images/default-source/jblstory/innovation/technology/cmcd_callout.png?sfvrsn=2
But POOH, you should get round or oval horns for mids and upper mids. They sound smoother.
I noticed that the JBL CMCD has a very small spider. Maybe this driver is not to be used for midbass at all. And yes, the back chamber is very small.
www.jblpro.com/images/default-source/jblstory/innovation/technology/cmcd_callout.png?sfvrsn=2
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Rewind - if you look at my avatar pic you'll see i have round horns. I actually have lots of them. oval too!
I have found you can use drivers below the fs provided you have enough horn - so have many other horn lovers. The horn has a molded 3" throat that should work fine with 6 inch cones. After Christmas I will play around with a couple of bigger 8" drivers I have used in horns before.
To refrain from trashing this thread anymore I'll post in one i started with my system.
Happy holidays folks!
oval too!I have found you can use drivers below the fs provided you have enough horn - so have many other horn lovers. The horn has a molded 3" throat that should work fine with 6 inch cones. After Christmas I will play around with a couple of bigger 8" drivers I have used in horns before.
To refrain from trashing this thread anymore I'll post in one i started with my system.
Happy holidays folks!