Really Boring Stuff Only III: Resurrection

Alex2507

Alex2507

Audioholic Slumlord
Jeff has built one or two designs in his day and his comments about this little tower have been that he can't stop listening to them. IMO, that's a pretty big indictment given how positive the comments have been about the Kairos from people who have built them and himself. I feel the compulsive urge to build them and see how they fair against the Phil 3's. RAAL/ML-TL vs RAAL/ML-TL. Both ML-TL's were designed by Paul K.
Paul Kittenger, right? One of those guys designed the software for that Quarter Wave Transmission line business ... Swerd told me the whole story a while ago ... there was even an analogy about mass loading. It's a cool trick if you can pull it off.

Jeff also said he was looking into a 3-way design of the tower using, possibly the CSS SDX10 or an SB woofer. However, when I asked him what sort of time frame he had in mind for that he told me, "...don't hold your breathe." So it looks like that will be awhile if at all. Still, if I build this tower I'll have almost all the parts for the 3-way version so I could always do a re-build if the fancy strikes me.
The 2.5 way keeps stuff simple and is likely your best shot at space conservation and ease of build. It would be even better if the design could make use of existing PE cabinets.

Not speaker related, but this happened to pop into my mind after reading someone's comment online about an intern thinking that Washington, D.C. was up by Oregon.

I remember asking a freshman in physics to measure out some distance in a lab that I was working in back in grad school, and then after my brain comprehended what he said to me and I pushed my jaw back into place, I spent the next five to ten minutes explaining to him how to use a tape measure and what all of the numbers and little marks between the numbers meant.
I had a guy like that work for me. No wonder his cuts were off. He was trying to fake it ... you can't fake that.

Cool new multi quote button! :D
 
Alex2507

Alex2507

Audioholic Slumlord
Is there one, or are you just joking? :) I'm probably just blind. I just hit reply on all of the ones that I want to quote, and it builds up in the reply box.
I'm just messin' with YAA. I knew he had asked about one.
 
Adam

Adam

Audioholic Jedi
I'm just messin' with YAA. I knew he had asked about one.
Well, at least you got me to look. :)

Took Niki for a drive/walk after lunch. Now I'm just doing some laundry, drinking a cold IPA, and watching Legend of the Seeker. It's nice to relax.
 
Swerd

Swerd

Audioholic Warlord
Cool new multi quote button! :D
Is there one, or are you just joking? :) I'm probably just blind. I just hit reply on all of the ones that I want to quote, and it builds up in the reply box.
Is that how you do a multi-quote? I've been wondering that myself.

Paul Kittenger, right? One of those guys designed the software for that Quarter Wave Transmission line business ... Swerd told me the whole story a while ago ... there was even an analogy about mass loading. It's a cool trick if you can pull it off.
Martin J. King is the guy who made the design software for the QWT. Paul is the guy who seems to know how to use it well, and is the guy who likes to team up with people like Dennis, Jim Salk, Jeff Bagby, etc.

The mass loading analogy goes something like this:

The vibrating column of air inside a MLTL speaker cabinet is like a metal ruler clamped to the edge of a table with some overhang. A single speaker pulse gets the air in the cabinet vibrating, and a single pluck of the ruler gets it vibrating. The speaker cabinet's resonant frequency varies with the length of the column of air, and the ruler's vibration varies with the length of overhang. The longer the speaker cabinet, or the longer the overhang, the slower the vibrations.

If you clamp a weight on the overhanging end of the ruler, the vibrations get slower without making the overhang longer. Similarly, if you put a short wide port near the end of the column of air in the speaker cabinet, it slows the resonant vibrations of the cabinet. That's why M.J. King calls it a "mass loaded" transmission line.​

It lets you tune a cabinet to a lower frequency without making it impractically long. King's software lets you predict how well it works with a given woofer by letting you do trial & error on the computer, rather than with lots of different size wood cabinets.
 
fuzz092888

fuzz092888

Audioholic Warlord
Paul Kittenger, right? One of those guys designed the software for that Quarter Wave Transmission line business ... Swerd told me the whole story a while ago ... there was even an analogy about mass loading. It's a cool trick if you can pull it off.
The quarter wave software is Martin King. I also happen to have said software, although no idea how to use it. I've played with it a little, but can't make hide nor hair of it.

The 2.5 way keeps stuff simple and is likely your best shot at space conservation and ease of build. It would be even better if the design could make use of existing PE cabinets.
Given that it's an ML-TL, I doubt construction will be all that simple, but hey I can hope. I guess it would be more difficult if it was a folded ML-TL though like the Phils.

Cool new multi quote button! :D
Way to get my hopes up :mad:
 
Swerd

Swerd

Audioholic Warlord
Given that it's an ML-TL, I doubt construction will be all that simple, but hey I can hope. I guess it would be more difficult if it was a folded ML-TL though like the Phils.
The ER18 MTM is an MLTL cabinet (designed by Paul Kittinger no less), and it isn't any more difficult to build than any other tower. No folded pathway in them.
 
H

herbu

Audioholic Samurai
I feel the compulsive urge to build them and see how they fair against the Phil 3's. RAAL/ML-TL vs RAAL/ML-TL. Both ML-TL's were designed by Paul K.
Something tells me it wouldn't be an apples-to-apples comparison due to the size difference. I'm guessing there is something going on in that big Phil3 base that cannot be easily duplicated in a normal "slim" tower.
 
fuzz092888

fuzz092888

Audioholic Warlord
Something tells me it wouldn't be an apples-to-apples comparison due to the size difference. I'm guessing there is something going on in that big Phil3 base that cannot be easily duplicated in a normal "slim" tower.
It may, or it may not be. Its a 3 way with a big folded ML-TL vs a 2.5 way with a single line ML-TL. Now, if we're talking about raw output the Phil's might have the edge, especially since that revelator is one heck of a woofer. However, the mid/bass in the Testarossa's is shared between the two midwoofers. Both are enhanced with the ML-TL, so it may end up being more even than not, output wise anyways.

As far as extension goes, IIRC the Testarossa's might have the lower F3.

Either way I'm sure it come down to subtleties more than large differences. Sure they'll both have their own character and "sound", but Dennis and Jeff are two excellent and experienced designers that go for neutrality and accuracy so it'll be fun to compare a reference-ish tower from each and see how they tackled the " problem" at around the same price point.
 
fuzz092888

fuzz092888

Audioholic Warlord
Something tells me it wouldn't be an apples-to-apples comparison due to the size difference. I'm guessing there is something going on in that big Phil3 base that cannot be easily duplicated in a normal "slim" tower.
It may, or it may not be. Its a 3 way with a big folded ML-TL vs a 2.5 way with a single line ML-TL. Now, if we're talking about raw output the Phil's might have the edge, especially since that revelator is one heck of a woofer. However, the mid/bass in the Testarossa's is shared between the two midwoofers. Both are enhanced with the ML-TL, so it may end up being more even than not, output wise anyways.

As far as extension goes, IIRC the Testarossa's might have the lower F3.

Either way I'm sure it come down to subtleties more than large differences. Sure they'll both have their own character and "sound", but Dennis and Jeff are two excellent and experienced designers that go for neutrality and accuracy so it'll be fun to compare a reference-ish tower from each and see how they tackled the " problem" at around the same price point.


I'll also add that the original slim tower Dennis designed easily rivaled the Phil 3 within its operating bandwidth (about 10 hz less extension I think)
 
lsiberian

lsiberian

Audioholic Overlord
We are talking about 3 ways and Alex didn't post one of his great pictoral examples for us?
 
fuzz092888

fuzz092888

Audioholic Warlord
Perhaps he's still thinking about how to make fun of you for your double posting this morning instead of just editing the original. :p
I can't help it, I'm at a PD day and I'm on my phone. The connection here is glitchy as all get out.
 
Alex2507

Alex2507

Audioholic Slumlord
That's a great move. Tell her we said good luck!
They sound like nice doors too.



Or try running the center a little hot?
I'm always torn. So much material gets sent to the center channel.
It's a juggling act, between hearing dialogue (being loud enough) and not over heating the voice coil.
I over think stuff. Always knowing the power has to dissipate somehow and the voice coil gets a lot of heat.
Speakers that have phase plugs, that helps.
I do run the center about 2 db hot. YAA had sent me a BR Demo Disc that had a particular performance called something like Jail house Tango of Jail house Blues. Smokin' hot song and dance by these fine as frog's hair chicks. Anyway I thought it sounded a little nicer being pushed by the Aragon. Not enough nicer to put up with lost space and all those wires. This might be a sign of growing up.
 

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