WHY are TL cabinets referred to as Theile?

[Scottunes]

Short story long, I bought several EV speakers in the 70s for replacements... Sometime in the early 80s I'd heard about the EV speaker cabinet plans, and wrote EV for them, explaining that I'd recently bought a few EV speakers. They kindly sent the plans to me at no charge! Well, life got in the way, and I didn't get around to building any of them until the late 90s!! I built 4 cabinets, and am proud to say, all are still in business!

Recently, I pulled the plans out again, thinking I'd make "mates" for my TL606 and TL806 cabs, and a few extra TL806 cabs for friends, and maybe sell a couple to defray the costs...

These plans were evidently drawn up by Someone named Keele specifically for Electro-Voice speakers. I didn't see the name Thiele on/in the plans anywhere. The model designations are TL, not Thiele... Hence, my question:

WHY are EV designed TL cabinets referred to as Thiele cabinets?

Thank you for your attention!

 

[teemuk]

Thiele, not "Theile".

Electro Voice plans to develop a successfully working vented cabinet were largely based on theories presented by R.H. Small and A.N. Thiele: Now ideal cabinet and port dimensions could be calculated mathematically, instead of deriving them painfully by trial and error. Even today loudspeaker development very much relies on so-called Thiele/Small parameters and design rules outlined by the gentlemen. Yes, in E-V's case, D.B. Keele's theories of cabinet "aligning" also had great influence in this process.

As far as I know, Electro-Voice didn't call any of their cab series "Thiele". Mesa/Boogie, however, later built a cabinet based on E-V plans (basically TL806 enclosure), which was sold under that moniker. I think since then people just stuck to using the word "Thiele" whenever they refer to a certain type vented enclosure.

 

[tucsonsound]

EV cabs were dubbed "Transmission Line." Mesa cabs were built on the same Thiele-Small parameters and dubbed "Thiele" in an attempt to reference the design they were copying.

 

[Kelly]

More correctly, they are tuned port cabinets. The port can boost output at the frequency it is tuned to by 3 db. Thiele/Small parameters apply to all cabs (closed, ported, open, or other). The benefits of tuned port over sealed is the 3db boost and looser tone (if you prefer loose). The downside is slight loss in power handling. Basic stuff in FOH sound and car audio, but there always seems to be confusion in the guitar world about speaker design.

 

[Scottunes]

Thiele, not "Theile".

Electro Voice plans to develop a successfully working vented cabinet were largely based on theories presented by R.H. Small and A.N. Thiele: Now ideal cabinet and port dimensions could be calculated mathematically, instead of deriving them painfully by trial and error. Even today loudspeaker development very much relies on so-called Thiele/Small parameters and design rules outlined by the gentlemen. Yes, in E-V's case, D.B. Keele's theories of cabinet "aligning" also had great influence in this process.

As far as I know, Electro-Voice didn't call any of their cab series "Thiele". Mesa/Boogie, however, later built a cabinet based on E-V plans (basically TL806 enclosure), which was sold under that moniker. I think since then people just stuck to using the word "Thiele" whenever they refer to a certain type vented enclosure.

Spelling corrected (except title)...

I must have written that name a hundred times, and for some reason got it wrong 4 time this post!

VERY familiar with T&S parameters.

Just in the last few years it seems Thiele has been used to describe the Keele designed EV cabs... And, mostly the 1x12 design, and not the 1x15, or Quad designs... Again, supporting your theory that it's a Mesa thang...