I have a pair of Odeon Rigolettos aka Einstein Rigolettos. They are categorized as TQWT, but I've not been able to find any others online that have the same characteristics. They have Audax tweeters and modified Fostex FE164. But... the bottoms are open, so the entire bottom of the speaker acts as a port I suppose. They stand on wood plinths. Any idea what specific sub-category of TQWT they are? Thanks for any help.
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By TQWT i mean Classic TQWT, a taperd pipe with the driver mounted ~1/3 distance along from the (smaller) closed end. These typically have significant ripple in the bass, althou corner loading can help (as in the BIB)
To mass load them you could add a bottom, or you could just shorten the height of the bottom off its plinth. The original MJK ML-TQWT design was for FE164 so that is a reference you should read.
dave
To mass load them you could add a bottom, or you could just shorten the height of the bottom off its plinth. The original MJK ML-TQWT design was for FE164 so that is a reference you should read.
dave
I believe the open ended TQWT is often referred to as a Voigt-pipe.
It also appears to be similar to the iBiB (Inverted BIB) discussed on this forum.
Depending on the internal geometry it could also be a kind of horn (or really horn mouthed BVR), as in the British Impulse series of speakers.
SveinB
It also appears to be similar to the iBiB (Inverted BIB) discussed on this forum.
Depending on the internal geometry it could also be a kind of horn (or really horn mouthed BVR), as in the British Impulse series of speakers.
SveinB
OK... please forgive my ignorance.... I guess I just don't understand the definition of "mass loading". I thought you meant loading with sand or gravel. As far as the internal structure, it's typical TQWT. There's an MDF board that starts at the front bottom and is slanted backward all the up to just below the Fostex driver. If I was to add a bottom to the cabinet, I would still have to port it, correct? And a front port would be in the way of the internal "slanted board".... so it would have to be in the back of the cabinet.
From what I can make of the Manufacturer's site and your description, this would more likely be classified in today's jargon as a chamberless folded tapped back loaded horn - so Svein is probably close with his guess at inverted BIB
Provided you don't mind a bit of fiddling about with reversible mods, it couldn't hurt to reduce the height to the floor, play with levels of stuffing, and/or fill the opening with a wood plate including port. The trick of course to the latter is determining the port dimensions and damping by methods other than iterative trial and error - which is where the math that Dave referred to as described on MJK's site is invaluable.
It is definitely not a TQWT!
It is a traditional BLH with a chamber. There is a chamber, and then two conical expansions approximating an exponential expansion. I have a set in the garage.
Take off the FE164, reach your hand inside. You'll see a divider that slants -toward- the front of the cab. That forms the chamber. At the bottom of that divider, there is a little "shelf" and that forms the throat. The back of the divider forms the first expansion, which goes up. Then it turns 180 degrees and comes down to the terminus (which fires at the floor).
So three "sections" -- the first is the chamber, the second and third conicals approximate an exponential.
It is a traditional BLH with a chamber. There is a chamber, and then two conical expansions approximating an exponential expansion. I have a set in the garage.
Take off the FE164, reach your hand inside. You'll see a divider that slants -toward- the front of the cab. That forms the chamber. At the bottom of that divider, there is a little "shelf" and that forms the throat. The back of the divider forms the first expansion, which goes up. Then it turns 180 degrees and comes down to the terminus (which fires at the floor).
So three "sections" -- the first is the chamber, the second and third conicals approximate an exponential.
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I have also read posts that categorize them as BLH speakers. The only thing I can see when I turn the speakers on-end is a board which starts at the bottom front of the cabinet and slants backward. The board/divider ends rite around the magnet of the Fostex. I don't see a "shelf". The divider board just stops... no other turns or bends. The chamber created between the divider and the front of the speaker is stuffed... and the area behind the drivers is fully stuffed with damping material as well.
mr B: thanks for the correction - playing around much with extensive re-engineering of these might not be such a wonderful idea after all
, but adjusting damping levels in the driver chamber and playing with boundary locations ( a la BIB) couldn't hurt. Did you find they needed any help? We should probably ask robber222: is there something about the system performance that you deem needs correction, or were you merely interested in what to call them?
they look pretty much the speaker in this link.... except the front is closed (no port) and the bottom is wide open. Same slanted divider board and geometry.http://www.cadillac.demon.nl/images/TQWT9710m.jpg
this is an even better example of the innards:http://img472.imageshack.us/img472/1604/79398063cy0.jpg
and that is a IBIB by Terry Cain... so is that what I have?
and that is a IBIB by Terry Cain... so is that what I have?
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We'll let owners of the Odeons discuss that, but I rather doubt that Terry would have constructed any loudspeaker from MDF. The only BIB of his that I'm aware of was full height with a top firing terminus, mitre folded joinery and lathe turned "supra baffle".
He did of course inspire a lot of us with his "DIY" take on this design BIB as published here:
Single Driver Website
Those who've seen any of his personal handiwork would know that few "DIYers" could aspire to the quality of his craftsmanship even on a 3-hr "slapped together prototype" He may have only constructed a couple of pairs of these before moving on to other designs, and "accidentally" becoming a loudspeaker manufacturer. All of us in the commercial woodworking trade should be so gutsy as to take that chance, or deserving of the respect, admiration and business success he enjoyed.
Of course his most widely known and heard product at other than trade shows would likely have been the Abby (even more elegant in my opinion), the tradition of his work being carried on by Jason Flanary
Lovecraft Designs Audio Equipment
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regarding the link/photo which mentioned Terry Cain... the builder of the speakers in the photo was merely claiming they were a design of Terry's... NOT an actual build of his. The photo is from a 300+ page thread on this very forum. So.... it appears I have an IBIB set of speakers. Is it also a back-loaded horn?
I wanted to know exactly what I have on my hands / what to call them, but I like to tweak here and there, so I wanted to know which tweaks have worked well for others. But in order to search for tweaks on different forums, I wanted to know which type of speaker I have. So far I've just done mods to the Fostex drivers. They are:
1. Rope caulked the baskets/spiders.
2. Dynamat on the backs of the magnets.
3. Phase plugs made from small vacuum tubes.
4. Mod Podged the cones.
I also put wool felt around the tweeters. I've been wondering what I could do with the cabs to tweak them even more.
Your horn's innards have two dividers, not one (like a BiB).Take off the FE164, reach your hand inside and down -- you will notice there is a little "shelf". You can feel that you have two dividers, not one.
The divider right behind the driver is made of particle board, whereas the other divider is MDF. You've got a chambered BLH, not a TQWT.
By the way, I immediately disconnected the tweeter on my (I felt it was blazing hot). I just ran them with no tweeter, and I reduced the amount of that gray wool felt in the chamber.
One other note: I was never able to improve the bass by modifying the box's height -- after days of trying, I eventually concluded it's already at the optimal height
Your horn's innards have two dividers, not one (like a BiB).Take off the FE164, reach your hand inside and down -- you will notice there is a little "shelf". You can feel that you have two dividers, not one.
The divider right behind the driver is made of particle board, whereas the other divider is MDF. You've got a chambered BLH, not a TQWT.
By the way, I immediately disconnected the tweeter on my (I felt it was blazing hot). I just ran them with no tweeter, and I reduced the amount of that gray wool felt in the chamber.
One other note: I was never able to improve the bass by modifying the box's height -- after days of trying, I eventually concluded it's already at the optimal height
So you have a pair of Rigolettos as well? Or something similar? Didn't the highs suffer from the lack of the tweeter? What effect would removing some of the gray wool have?
Hi robber222,
Yes, I have a pair. Personally, I found the tweeter to be too much, so I disconnected it, and that's when I found that monster crossover inside.
To my ears, it sounded better with no tweeter, and no crossover. I physically removed the crossover and was surprised at the amount of stuffing in the chamber. I removed about half, in the end.
(If you like the tweeter, by all means leave it in but at the very least, I would pad it down a bit more.)
Eventually I changed out the FE164 driver as well, with a different Fostex, but I had not done any simulating at that point. I have been waiting to have enough free time to get back to it (oh man!)
Yes, I have a pair. Personally, I found the tweeter to be too much, so I disconnected it, and that's when I found that monster crossover inside.
To my ears, it sounded better with no tweeter, and no crossover. I physically removed the crossover and was surprised at the amount of stuffing in the chamber. I removed about half, in the end.
(If you like the tweeter, by all means leave it in but at the very least, I would pad it down a bit more.)
Eventually I changed out the FE164 driver as well, with a different Fostex, but I had not done any simulating at that point. I have been waiting to have enough free time to get back to it (oh man!)
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