anyone got DIY thiele cab pics? plans?

[Boogafunk]

the port cover essintially changes the port tuning of the enclosure. there is no magic about it, but a lot of thought went into it. part of the port becomes airspace and the new port dimensions are in line with what ev thought would be a viable second option. actually a fairly complicated calculation. i myself prefer the stock configuration, as do 95% of the people who have tried both. there is more bass available but it must eq'ed in. this is a less ideal situation when playing loud, as the maximum excursion and power handling of the driver limits this "extra bass". the plans say it best. "eq will have no affect on the maximum output of the speaker" at higher volumes you will find that you have to take all that extra bass back out of the speaker and you will end up with less than the stock configuration. of course we are talking about an ev that will take a lot of punishment, but take into consideration that the 6db of eq that they recommend effectivly quadruples the power demand on the amplifier in that bandwidth you can see where you might start getting into trouble.

as far as the c90 working in a thiel, two speakers can have similar enough parameters to work in the same enclosures. the alternate speaker might perform well in said enclosure but often it isn't quite as good as the original, from an audiophile point of view. however, as guitar sound is the most subjective thing on the planet, maby the "mistake" sound good to you. the c90 imo (from the very limited time i have spent with one) is a pretty clean sounding celestion, as opposed to the more breakup oriented greenback or alnico blue. it has been tested and approved by mesa as a viable alternative to the ev in their thiele. i won't argue with that. many people love that combo. celestion is rather tight lipped about their specs so i can't model one for comparison. (if anyone can send me a link i will post the results)

the only issue i have about using the c90 is power handling. i would advise using 2 or more for most stage rigs. whereas i wholeheartedly believe that one ev loaded thiele in more than a match for almost any situation. (two is really cool though)

different strokes for different folks.

btw i did try a celestion clone that a guy gave me to test in a thiele. i think it was modeled after the gt75. the results were beyond terrible, subjective or not, it was truly horrible.

 

[trickyrick]

Rick you should really read the EV plans spec sheet to understand the purpose of the port cover and why it would or would not be used.

The port cover, as stated on their sheet is for:

"The design provides the selction of two different low frequency response curves by the potional use of a removeable port. In normal configuration (port cover off) the response is flat down to the lowest frequency. In the step down configuration (port cover on) the resposnse exhibits a sloping gradual low frequency rolloff but with about a one-half octave extension of low end response. The stpe down mode of operation is intended to be used with simple before-the-power-amp equalization to flatten the response....."

Yes all is subjective to ones own ear...
but there is physical science (physics) behind the design.

I understand ( as far as my limited knowledge on the subject allows ) what the purpose of the port cover does. I was only trying to make the point that tone is subjective. If one were to make a cabinet out of aluminum foil and tooth picks and loaded it with whatever driver and it sounded great, then that is a happy player. Assuming of course that player new what good tone was to begin with. I am talking about myself of course, I am not trying to insult anyone.

Whether or not I happened to get lucky and nail the presise dimensions of the cab, or a slightly different design given what I was trying to attempt, the end result ( for me ) is still a pleasent one. I smile when I play. That's all I care about.

 

[Expendable]

Howdo folks,
Well the project is coming along nicely, would like to ask some of ye here
does it matter what gauge speaker wire I should use, or maybe someone can recommend one.
Also any website recommendations for tolex/jack/jack dish/speaker wire purchases.
Thanks again

 

[Boogafunk]

rick, i have modeled the ev thiele on my computer for reference. changing the box volume within a certain range seems to have a minimal effect. between 1.5 and 1.1 seems to have less than a 1db effect on the frequency response centered around 100hz. this was just a quick check and i didn't delve into it too deep. to really be accurate i would have to change the port dimensions back to stock every time i changed the volume as the tuning will change slightly with a different sized box, but i feel that it is a pretty good indicator that there is just a bit of flexibillity within the design. 1.3 cubic feet still seems optimal but that is a relative term. i severely doubt that anyone othe than an rta meter could hear the difference between a "correct" thiele and one that was off by 10% of box volume. that's kind of suprising even to me. of course that is computerland, real life might throw a curve. i still wouldn't throw just any old speaker in it, but for those on a budget the emminence delta12 seems similar enough to work well, at least in bass response. high end and midrange it might suck, but i suspect it would be close to the ev's response. i might try one at some point and let you guys know how it turns out. i imagine it will be a better match than the c90, with a lot more power handling. i only imagine that boogie loads their thieles with c90s because they felt it had to have a speaker that said celestion on it, or no one would buy it. the c90 was probably the best out of the speakers they had to work with. i could be wrong but i don't think boogie has any high wattage speakers in any of their cabs or combos any more, so i don't think they wanted to find a replacement speaker that was unique to only one cab. a cab that isn't near as popular these days.

 

[trickyrick]

Hey BF, whats going on? This is a bit off topic, in that it really relates to another thread. I have had the chance to A/B the theile I built which is loaded with an older OEM EVM12L 300W with one that has been stranded in my local Samash for months now. It is a Mesa Theile loaded with a C90 ( they want $450 for it ) I actually brought in my combo and cabinet and played through them for nearly an hour. The staff was helpful and actually interested in the results. Everyone felt that the Widebody Theile sounded profoundly better.
One thing I did experiment with was the usage of a dampening material as you suggested. When I first tried it and thought I heard no difference, I really didn't use enough or arrange it well. So, I used poly about an inch thick and lined the cab with it and secured it with staples so the port was fully clear. Doing this certainly made a difference for the better. The cab is much tighter. It really sounds like a bigger cabinet. I am so glad I stumbled onto this site, the wealth of knowledge from everyone is vast. My next project..... A split 2-12 Stereo/Mono Theile/ with duel ports......Just kidding....although......

 

[dodger916]

Hey BF, whats going on? This is a bit off topic, in that it really relates to another thread. I have had the chance to A/B the theile I built which is loaded with an older OEM EVM12L 300W with one that has been stranded in my local Samash for months now. It is a Mesa Theile loaded with a C90 ( they want $450 for it ) I actually brought in my combo and cabinet and played through them for nearly an hour. The staff was helpful and actually interested in the results. Everyone felt that the Widebody Theile sounded profoundly better.

Hey Rick:

The obvious question: can you comment on how much of a role the EVM played in the improved performance?

 

[Boogafunk]

well rick, i hate to say i told you so.... anyway it doesn't suprise me that the ev loaded and properly damped enclosure sounded worlds better than the undamped c90 loaded cab. i actually did a similar comparison in the shop. a guy i know had us build a replica fender cab with some celestion clones. i plugged it in and it sounded great, until... i compared it to the thiele cabs. after that it just sounded marginally ok. i don't doubt that the c90 thiele sounded good but unless you hear the real deal next to it, you just don't know what you're missing. btw any of you out there with mesa thieles can damp your cab for very little money. i'm sure the c90 loaded version would also benifit.

 

[jski59]

Hey guys,

I've been following these threads closely, so this weekend I took
the plunge and copied Trickyrick's design for a widebody Thiele.

So far, I'm really impressed with the amount of bass this little enclosure
puts out. I don't have the correct speaker in it yet (just some old Eminence from the early 90's), but I have a Delta 12 Pro on the way.
I figured I'd give it a shot. I'll probably try an EV too...since I don't really
like the c90 in my widebody combo, I can always throw the EV in there after I try them both in the Thiele.

We kind of screwed up when we built mine...everything is to the ev specs, but we messed up on the location of the dummy wall. We had a line drawn where it should go, but mistakenly installed the board on the wrong side of the damned line! Ugh. So my cabinet is technically 3/4 of an inch too narrow. I think I calculated the internal space around 1.23 cubic feet.

Based on what you guys are saying, hopefully this won't have too much effect on the tone.

By the way, thanks for all the great info and ideas. I've played through the same 4x12 for the last 20 years, so this is a fun experiment!

Jason

 

[Boogafunk]

jski59, i mentioned earlier in this thread that i had modeled a thiele with en ev. i also modeled a thiele with a delta and a deltapro. the two delta's seem to be very, very close if i remember right. i would go with the regular delta just because it's lighter and less expensive, but the deltapro is on my list of possible substitutes for the ev. as far as the airspace i wouldn't be super concerned. if the baffle wasn't glued i would probably try and redo it, but if it's glued then forget it and go with it. i'm not sure about with the delta but with the ev that would equate to less than 1 db difference in bass response. (on paper at least) if i remember right the delta seemed like it would be slightly happier in a slightly larger box than the ev, but that's splitting hairs. i'll try and dig up my old files on the delta speakers so i can refresh my memory. i would definately be interested in hearing your comparison of the ev vs. the delta in the thiele. it is something i have planned on doing myself, but i don't know when i'll get around to it. do you happen to know what model speaker you have in there currently?

 

[jski59]

Hey Boogafunk,

Yeah, the whole enclosure was complete before we realized our error...oh well. My buddy's really good at woodworking, so if I like the sound of this, we might build a nice hardwood version. We'll fix our mistake then...

The current speaker is an Eminence 12ls16. I've got 2 brand new ones that were given to me back in the early 90's. I couldn't find any specs on them, but I did find someone on the net mention they were similar to Greenbacks. Anyway, I just threw one in there to give it a try...

I'm definitely going to try a EV so I'll let you know how that sounds. I wish I could a/b it with a Mesa Thiele so I could evalute it. Like I mentioned before, I've been playing through the same cab for so long it's hard to decide if "different" is "better".

Actually, right now it doesn't sound that great but I'm hoping a better speaker will be an improvement.

Jason

 

[Boogafunk]

if that speaker it anything close to a greenback i am not suprised you don't like it. that kind of a high breakup speaker just sounds horrible in a thiel, to me. definately audition an ev.

 

[trickyrick]

Hey BF, whats going on? This is a bit off topic, in that it really relates to another thread. I have had the chance to A/B the theile I built which is loaded with an older OEM EVM12L 300W with one that has been stranded in my local Samash for months now. It is a Mesa Theile loaded with a C90 ( they want $450 for it ) I actually brought in my combo and cabinet and played through them for nearly an hour. The staff was helpful and actually interested in the results. Everyone felt that the Widebody Theile sounded profoundly better.

Hey Rick:

The obvious question: can you comment on how much of a role the EVM played in the improved performance?

A huge roll, no question! The C90 is a good speaker for what it is, but it doesn't match the EV. Remember, there were like 6 guy's that heard the test, and we all agreed. It was a no brainer.

For those of you who would like to add dampening material to your cabs, check this out.... It is closing in on the Christmas season, just go into any store and they already have displys up. O go into Lowes and they have that fake poly snow out. The bag was like the size of a pillow and it was only $6. So what I did was I lined my cab with it as I explained in a previous post and I took the rest of it and shoved it into the empty space created by the dummy wall. I am unsure if this makes a difference, but at least it's not going to waste. Something to look into JSKI59.

I am still waiting on ampwares for my S%&@. New grill cloth and handle. I called him early in the week and he said he shipped it last Friday. It's now Friday and I still have not gotten it. PA to VA is only a short distance. I am suprised I even got through to him. Oh well.

 

[trickyrick]

I am still waiting on ampwares for my S%&@. New grill cloth and handle. I called him early in the week and he said he shipped it last Friday. It's now Friday and I still have not gotten it. PA to VA is only a short distance. I am suprised I even got through to him. Oh well.

Rick,

Were you trying to match Mesa grille clothe?
If so when it shows up let me know if it is a match.
and which style model # grille clothe you ordered?

Sure dude, it is the "Marshall" Clothe which looks like the mesa jute. The problem is I am not really trusting this guy right now. I have researched problems with Ampwares and there are a bunch of hits. Nearly everyone has complained about him. I am going to call again today and hope his mailbox isn't full and that he answers the phone because he certainly doesn't reply to e-mails. I will let you know.

 

[jski59]

I hope you get the cloth...I was looking at that very same stuff. It
looked very close to my combo's cloth.

UPS brought my Delta Pro today so I'll let you guys know how it sounds.

It'll probably take awhile for it to break in...better warn the neighbors. :twisted:

Jason

 

[jski59]

Rick,

By the way, how much Tolex did you use? I found a guy on ebay selling
the Mesa style for around $15 a yard.

Should I get a couple yards? I've never done this before and will
probably screw it up.

Jason

 

[trickyrick]

Rick,

By the way, how much Tolex did you use? I found a guy on ebay selling
the Mesa style for around $15 a yard.

Should I get a couple yards? I've never done this before and will
probably screw it up.

Jason

Wow man, $15 a yard is a good price. I got upholstery from a fabiric store and it was about the same price the back is heavy duty marine grade stuff and holds the glue well with no bleed through. You may want to look at that option. There were some really nice colors too and I found one really close to the mesa stuff. If I were to do it again, I would use a tan with tan grill, there were a lot of colors and textures to choose from. If I were to do it over, I would make 2 cabs and a head out of exotic wood anyway which I am sure I will do when I feel a change is needed. Anyway, getting back to the topic. I bought 2 yards, and it was 54" wide so I have enough left over to do a couple of heads or a smaller cabinet.

This is how I did the tolex. I laid the stuff out and made a grid with magic marker for each side on the back side and I glued one side at a time. I tried to make the seam on the bottom about a 1/2" from the side. I put a couple of peices of tape on the cab where the seam will be so no glue gets on that area. Once all of the sides were cured, I removed the tape and cut both pieces at the same time to get the seam to match. Then I pealed back the unglued tolex and held them with some wood scapes. I applied the glue to both peices let it dry and carefully lined up the seams. In theory this would work well, but I cut them a bit short and stretched the tolex too much so that when the glue dried, it shrunk back a bit. No big deal, it's on the bottom, and the corner protector will hide the front and rear seam. Use dap contact cement. I suggest the water based stuff. the S&*t stinks so spend the extra $2 and get the non toxic stuff, it works just as well. Just remember you get one shot at it. You can put wood stipes between the cab and tolex and remove them one at a time while working the 2 together. Press the center first and work your way out. Do the front are rear last. Enjoy it and take your time and you will be happy. Good luck.

 

[trickyrick]

I hope you get the cloth...I was looking at that very same stuff. It
looked very close to my combo's cloth.

UPS brought my Delta Pro today so I'll let you guys know how it sounds.

It'll probably take awhile for it to break in...better warn the neighbors. :twisted:

Jason

I called him earlier and left a message, he did't return the call. I called him a little while ago, and he answered. He said he shipped it USPS last Friday. It usually takes 2 days, but not here yet. He asked me to give it until monday, 2 more postal days and I agreed. He said If I don't get it by then he will overnight the stuff to me. The only problem I have is that I don't trust him at this point. His gesture is nice but I really don't think he even shipped it yet. If I don't get it Monday I may ask hime to credit my card which I am not to confident about either. By the looks of the web page, it is the same as the mesa jute. I am such a pesimest right now I bet the photo is misleading and the cloth looks nothing like it. Crap, I am going to go play. Loud. Later.

 

[Supertaster]

Hi guys,
I've been watching this thread and I thought I'd share my experiences building a speaker cab a few weeks ago.

I was going to build a Thiele to use with my Mark III, but I've got no building skills whatsoever. Instead I picked up a booklet by Kevin O'Conner (sp) on cab design. His concept seems very similar to Thiele but is a lot simpler and therefore easier to build. Essentially the idea is this:

For a speaker of a given diameter you build a cab of a specific volume (the dimensions you use to get that volume are not really important) and include a port (untuned) of the same area as the surface area of the speaker cone. It just so happens that this is identical to the size of the cut-out you need to cut for the driver. Therefore, for a 1X12 cab, you build it to the size of a 2X12, cut two holes in the baffle as if you are going to mount two drivers, but only mount one.

I kicked around in my shed and found some MDF, borrowed my neighbour's Triton work bench and ordered a few Lorantz speakers of different sizes (these are a great Australian brand of speaker) and whipped up a ported 1X10 (that was all the MDF I had).

The end result? The most amazing cab I've ever used. It sounds for all the world like a killer stack with a big, clear bottom end, and it's all coming from a 1X10! Being the scientist I am, I did a few experiments. First, I mounted another 1X10 in the port. It sounded OK, but about half as big as the single speaker on its own. Next, I clamped a bit of wood over the port and again it sounded half as big. Next, I ripped a speaker out of my mate's new 2X12 Fender cab and it sounded all the better for it. I'll be building a ported 1X12 as soon as I get time.

So as a bit of an experiment, if any of you guys have a closed back cab, try removing half the speakers and see how it sounds. I have no doubt that a Thiele does the same thing more efficiently, but it could be a quick fix.

 

[Boogafunk]

ok i have to ask, who is this guy. i hope a lot of the science behind this design was lost in translation, cause the way you explained it flies in the face of loudspeaker theory.

 

[Supertaster]

Here's a link from the guy's homepage to the book I have: http://www.londonpower.com/books/spkr.htm

I admit I'm no speaker guru, but the principle seems pretty straightforward. I don't quite understand which part flies in the face of speaker theory- I thought this was the basic theory of an untuned ported cab. What he's really saying is that most closed-backed cabs have too many speakers for their size in an effort to be portable. This leads to sound pressure levels within the cab that inhibit the backward motion of the cone. This can be got around by either 1) Increasing the size of the cab (with the eventual loss of bass frequencies as the cabinet gets bigger-kind of like suspending a speaker in the air with no cab around it; or
2) Having a cab that's not too big and porting to allow some of the sound from the backward motion of the speaker to escape

So far so good: this is pretty standard for every ported cab (even though I may not be describing it particularly well).

This guy's 'innovation' is in realising that, in an un-tuned guitar cab, the ideal size of the port matches pretty closely the size of the baffle cut-out needed for a speaker. Coupled with some ideal cabinet volumes for each speaker size (which he provides in the booklet), this is a very simple way to build a ported cab. You could very easily build a cab to the exact width of your head or combo. Also, because it's not tuned, you can easily change drivers (of the same size) without having to rebuild the cab as you would for a tuned cab.

I tried it, it worked, and all of my guitar-playing buddies are amazed.