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Mesa style Thiele cab question
Posted: Tue Dec 31, 2013 1:36 am
by Geeze
I built this for a friend as an experiment. All of the pics I found on the 'net were externals. My question is what did Mesa do on the vented portion? My understanding of low frequency development is the longer the path the more developed or pronounced the bass is - limited to the length of the wave[s]. For this reason I put a shelf on top of the baffles and left an inch slot at the rear to channel the sound waves to the back before moving forward. Did Mesa 'cap' the vent and if so how big of a slot did they use?
I have the EV TL806Q plans and the ports are only 3.5 inches deep and do not get anywhere near the rear wall. What made this design so notable? The cabinet designed with T/S parameters coupled with the EV's or just EV's themselves?
The plan here is to put a EV in it and let her rip.
Re: Mesa style Thiele cab question
Posted: Tue Dec 31, 2013 2:33 am
by Reeltarded
Do not deviate from the plans and use the most similar materials you can find or don't expect anything great.
About the bass developing over distance. Take the speed of sound at sea level and then plot the wave at frequencies from 20Hz to 20kHz.
Basically, it takes 20Hz over 15m to develop a full wave.
Sound travel distance per second (appx:345m)/Frequency (cycles per second)
Google plate modes, standing waves, R2 function.. take a course on acoustical engineering..
The questions are interesting. The answers are not that simple.
Do not deviate from the plans and use as similar materials as possible. Just sayin'.
Re: Mesa style Thiele cab question
Posted: Tue Dec 31, 2013 9:32 pm
by Bill Moore
Here are the TL806 plans, (sorry, I added a few dimensions to the plans when I built one)
Re: Mesa style Thiele cab question
Posted: Wed Jan 01, 2014 9:00 pm
by Geeze
Plans?!?! We don' need no stinkin' plans! Oh, THOSE plans. Thank you Bill.
If the magic number is the 1.3 cubic feet = 2304 cubic inches I'm at 2309.625 cubic inches based on my version of the Mesa dimensions. They were a bit wider and shallower than the EV specs.
I plan to experiment with the shelf / one inch slot at the rear and the 3-1/2" shelf the plans call for.
Happy New Year!
Re: Mesa style Thiele cab question
Posted: Thu Jan 02, 2014 6:34 pm
by Bill Moore
Here is my take on a 2-12 version. I built some back in the day for mids for our R&R PA. Am using one now for pedal steel guitar.
Re: Mesa style Thiele cab question
Posted: Thu Jan 02, 2014 7:18 pm
by Structo
I always wanted to build a 2x 12 version of a TL806.
I believe several guys here have done it.
I just didn't want to spend the money and not have it sound good.
Do you have any insulation in yours Geeze?
This file is in German but the graphs are in English.
Re: Mesa style Thiele cab question
Posted: Thu Jan 02, 2014 7:47 pm
by Cantplay
You could make a removable insert for the port to change its tuning if you want to experiment.
John
Re: Mesa style Thiele cab question
Posted: Thu Jan 02, 2014 9:05 pm
by Bill Moore
Structo, I insulated mine, and left the port open. For a guitar speaker, I didn't see the need to reinforce the low end much.
Re: Mesa style Thiele cab question
Posted: Sun Jan 05, 2014 12:40 am
by billyz
I have built several 2x12 thiel cabs. loosely based on the EV tl806 dimensions doubled. I deviated alot . I used solid pine with 1/2 ply baffle and back. 4 ea round 4" ports. secret insides, ha ha. Sounds awesome I have been told.
I use left over Kimber wire and braid it appropriately.
funny I can't find a good pic of the front.
Re: Mesa style Thiele cab question
Posted: Sun Jan 05, 2014 1:02 am
by Geeze
Hi Tom,
I haven't given it the full power test yet - don't know if it will need to be dampened with insulation. Tomorrow I jam with my drumming child and we will see. No EV's on hand so a Gold or a Classic Lead 80 will have to do.
Billyz - nice shot of the 'secret insides'. I enjoy the experimentation - sometimes it works, sometimes not.
Re: Mesa style Thiele cab question
Posted: Mon Jan 06, 2014 6:14 pm
by Bill Moore
Geeze, I'll bet uninsulated will be fine for guitar, I'm curious what you discover. I no longer have my single cab to experiment with.
Billyz, that's a great looking cabinet!
Re: Mesa style Thiele cab question
Posted: Mon Jan 06, 2014 6:56 pm
by Structo
Interesting, Billy.
Is that a 12" and 10" speaker?
What is the clamp like thing around the posts?
Re: Mesa style Thiele cab question
Posted: Mon Jan 06, 2014 8:18 pm
by billyz
Structo wrote:Interesting, Billy.
Is that a 12" and 10" speaker?
What is the clamp like thing around the posts?
Secrets. its not a clamp but vibration dampning. also around the ports . if you look very close you can see some of the cross bracing peeking from under the foam insulation. The cab is very light but very stiff, those are 12" ASW elegante. One of the most beautiful sounding speakers I have ever heard.
Re: Mesa style Thiele cab question
Posted: Mon Jan 06, 2014 8:46 pm
by billyz
I am trying to load up some bad video clips done with the iphone. No special players, just friends. I am going to use Vimeo , Im done with youtube. Ever since Google Srewgled it, it is not happening for me . they lose my videos , cant login, wont play back all the time.
Re: Mesa style Thiele cab question
Posted: Mon Jan 06, 2014 10:22 pm
by billyz