Hello, newbie needs Thiele help

[vangit]

Hello. I'm new here, so I hope this is the proper section to post this question? I'v been doing research about Thiele's and EVM speakers. I read that EV originally designed the specs of the Thiele to have 1.3 cubic feet of internal volume and was 17 3/4 wide. I believe Mesa made various width Thieles. I was told the various widths were to fit a head on top?

My question is even though the width's may be different, do all the Thiele's that came with a stock EVM have the same 1.3 cubic feet of internal volume? My bud has a Mesa Thiele. The sticker on the back by the jack says it came standard with an EVM (the speaker is still in it). It has one input (can not daisy chain) and has the code c16489 on the jack plate. The top of the cab measures 18.5 across which is larger than the original design. But dose this cab even tough measuring 18.5 have the spec'd internal volume of 1.3 feet??

Any help would be appreciated.

 

[>Photi G<]

No, the Thiele cabs were not made to EV specs. They are close though. Mesa designed them so that the old Mark series combos, and short heads would sit evenly on them, without any overhang, or under hang. The EVM 12L went out of production somewhere in the mid '90s, so if you doubt what speaker your Thiele has in it, open it up and check. Modern Thiele cabs are loaded with Celestion C90s. EV has recently come out with an EVM 12L "Classic Reissue" that Mesa has yet to look into stocking.

 

[RR]

Subscriber of Speaker Builder Magazine, I would say MESA's Thiele is within EV's Thiele parameters. Looking at the design, of EV TL806, the internal volume, the port area and port length are similar to MESA's Thiele.

 

[vangit]

Thanks for the info guys. "RR", thanks for the info that you think the Mesa may be within the EV spec parameters. I would love to know....I can't find info (especially on the internal cubic volume). Photi G, yes the one I am talking about has the EV in it.

 

[RR]

There's nothing fancy about these speaker enclosures. When I say 'fancy', I mean no fancy internal bass reflex horn etc ... which is a good thing because that would add some coloration to the speaker's tone.

The EV theile is to get the most optimum performance out of EVM-12L. Say if you make the internal volume larger, you may get more bassy but looser bass tone. Smaller internal volume, you'll get a brighter tone, but lost in bass. There's always trade-off.

So EV R&D department came up with 1.3 cubic ft. for most optimum performance for an EVM-12L. Since these speaker enclosures have parallel sides, bottom and top, your concern of internal volume (which you state is 1.3 cubic ft.), port area, port duct length remain the same as the EV TL806 plans.

So just because enclosures width are different between the two, maybe the MESA makes it up in depth or height to get the 1.3 cubic ft.

 

[vangit]

So just because enclosures width are different between the two, maybe the MESA makes it up in depth or height to get the 1.3 cubic ft.

Hi thanks for writing. I know just because one cab may be wider, the internal volume may be the same. Boogafunk has a "wide" version of the TL806 plan.....but he just added wood to increase size for a head (the volume is the same). I'de love to know if Mesa's Thiels that came stock with EVM's are 1.3?

 

[Thatguy]

I built a thiele cab to the EV specs. And it sounds amazing! And looks identical to the Mesa. I'm just looking for the proper grill cloth. I have some temporary stuff on now. Super easy to build. Only took a couple hours to build and a couple to tolex. I'm a carpenter so I have all the right tools to do it, but I think anyone who has any experience at all could do it.

 

[RR]

some additional suggestion.

=> use caulking like those silicon caulking for kitchen and sinks on the corners and anywhere you think may leak air. Enclosure should be air or even better water tight for the duct to be effective.