Building a 1x12 Thiele/Small guitar cabinet.

I need a cab for an amp head I'm getting so ima gonna build one. Its based on the plans found here of the EV TL806:

http://archives.telex.com/archives/E...ders Plans.pdf

Seems like Mesa Boogie's cabs are based on this design. I know zilch about woodwork so I enlisted a family member to assist, well. to 'get 'er done' and I'll provide moral support. The handiwork is his, I'm just the helper.

I'm using MDF and pressure treated, dressed white pine for the braces on the inside. Cut the pieces yesterday, glued and nailed the enclosure together. BTW a nail gun is a wonderful thing. Clamped it and left it overnight, going back to do some more stuff on it after work today.

Pics:

Showing the back... I learnt yesterday that those are "sash clamps'.

http://i1234.photobucket.com/albums/...n296/spkr3.jpg

The knife was used to gently scrape the excess glue from the corners. Thats where the braces will go. The small white boxes are the 'ammo' for the nail gun.

http://i1234.photobucket.com/albums/...n296/spkr2.jpg

Shot of the inside. Disclaimer: Photos were done with my phone.

http://i1234.photobucket.com/albums/...n296/spkr4.jpg

Mods: First time I'm posting pics from photobucket so feel free to modify them.

More to follow...

Started putting in the internal bracing yesterday, nail, glue, wipe excess. We found that we were 1/16" off on the internal volume, we'll see what that does with the sound.

http://i1234.photobucket.com/albums/...n296/spkr6.jpg

Fitting in the bracing for the ports, ready to glue. The flat piece in front is a removable port cover. You can use the cab with or without it depending on your preference.

http://i1234.photobucket.com/albums/...n296/spkr8.jpg


Incidentally my cousin (the carpenter) called me this morning to tell me that he was going to work on it. He has a Gov't job, and home at 10:00 a.m. :socool

Wow, looking really good. Bet it will sound great with the Boogie. :dude

Thanks bcdon, lets hope it sounds good!

After intensive research and invaluable comments from Tung and Tig...(thanks guys)!

I decided on an Eminence Delta 12A Speaker for the cab. The thing is, its rated at 400W RMS, 800 peak, which flies in the face of all conventional wisdom.

Specs on the Delta here:

http://www.eminence.com/pdf/Delta_12A.pdf

From my googling, this seems to be ideal replacement for the EVM12L. It also seems that this speaker will not color the sound of an amp and has a 'better' sound than the EVM12 L which the speaker enclosure was designed for. Locally, I got one new for about $50 so what the heck, I'll try it. I need to figure out how to "break" in a speaker with a 9 volt battery.

On to the pics!

Internal bracing finished, including port area.

http://i1234.photobucket.com/albums/...296/spkr10.jpg


Cleaned up a little and from another angle. You can't see it very well. but the edges have been routed to a rounded edge.

http://i1234.photobucket.com/albums/...296/spkr11.jpg

Quote:

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Originally Posted by Monkus

From my googling, this seems to be ideal replacement for the EVM12L. It also seems that this speaker will not color the sound of an amp and has a 'better' sound than the EVM12 L which the speaker enclosure was designed for. Locally, I got one new for about $50 so what the heck, I'll try it. I need to figure out how to "break" in a speaker with a 9 volt battery.

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I wouldn't use a 9v battery, it is DC and could possibly overhead the voice coil. You need and AC source like a wall wart, a filament transformer or Variac.

The formula for figuring out the amount of wattage a particular voltage level will generate is V(squared)/R or ac voltage squared divided by the speaker's resistance. If you want to get technical, you should measure the DC resistance of the coil, which should be around 6.3 ohms for a speaker with an 8 ohm nominal impedance rating according to the Delta specs .pdf.

So for 25VAC, you get 25*25/6.3=99.2 watts. You may want to try lower AC voltage, even though the Delta is rated for 400 watts. The more wattage you put into the speaker, the louder it will be and that 60HZ tone will drive you nuts.

Looking at the specs for both the Delta 12A and the EVM 12L, the Thiele specs are close but not identical. I bet the Delta sounds fine. I'll be very interested as my Thiele cabs are loaded with Celestions, but I'd like to hear them with Delta speakers.

HTH.

Quote:

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Originally Posted by tunghaichuan

I wouldn't use a 9v battery, it is DC and could possibly overhead the voice coil. You need and AC source like a wall wart, a filament transformer or Variac.

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What is the purpose of this 'break-in' ? Are all speakers broke-in is some fashion or another (e.g. stereo speakers, tv speakers, &c)?

Quote:

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Originally Posted by bcdon

What is the purpose of this 'break-in' ? Are all speakers broke-in is some fashion or another (e.g. stereo speakers, tv speakers, &c)?

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The break in loosens up the parts. The consensus is that speakers sound better after being broken in. Some speakers can sound shrill and "stiff" and breaking them in can tame the ragged high end. This article explains it better than I can:

http://www.premierguitar.com/Magazin..._Speakers.aspx

Stereo speakers are a different animal. They have synthetic cones and surrounds, which do not loosen up over time like the paper cones in guitar speakers. Stereo speakers are typically played clean with no distortion in the signal, their purpose is to reproduce recorded sound. Guitar speakers generate music and there can be lots of harmonic distortion in the signal.

Quote:

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Originally Posted by tunghaichuan

.....Stereo speakers are a different animal. They have synthetic cones and surrounds, which do not loosen up over time like the paper cones in guitar speakers. Stereo speakers are typically played clean with no distortion in the signal, their purpose is to reproduce recorded sound. Guitar speakers generate music and there can be lots of harmonic distortion in the signal.

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Or as I like to say "Hi-Fi speakers are about reproducing the sound. Guitar speakers are about creating the sound" ;)

I've never really tried to break any in myself though. The speakers in my 4x12 were made in the 60's so I'm assuming they were broken in long before I acquired them :)

Quote:

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Originally Posted by Ch0jin

Or as I like to say "Hi-Fi speakers are about reproducing the sound. Guitar speakers are about creating the sound" ;)

I've never really tried to break any in myself though. The speakers in my 4x12 were made in the 60's so I'm assuming they were broken in long before I acquired them :)

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Isn't this akin to the 'worn' guitars? Why not wear them in yourself by natural use instead of speeding up the process by synthetic means.

From what I've read so far, it depends. Some speakers might have a brittle edge to them because of the components, stiffness as a result of the manufacturing process or any amount of other reasons. As the cone and coil moves, they relax within tolerances over time. Some might not. I guess the questions are: Do you want the broken in tone faster, or do you want to enjoy the entire breaking in process of the new speaker? Some more experienced fretters may chime in on this. The article from PG linked above explains it really well.

Personally, I would like the broken in tone of the speaker as fast as I can so I can evaluate my amp easily. May not be necessary but might be worth looking into.

FWIW.

Breaking in makes sense, I just had never heard of it before... there are so many tricks of the trade out there.

Thanks for the explanation guys! :dude

BTW, Monkus.. looking forward to the next round of pictures. :-)

Quote:

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Originally Posted by bcdon

Breaking in makes sense, I just had never heard of it before... there are so many tricks of the trade out there.

Thanks for the explanation guys! :dude

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Breaking a speaker in can also take a marginal or bad sounding speaker and improve the tone. I know an amp tech who had this particularly bad sounding speaker. He hooked it up to a sine wave generator and left it on over the weekend. He said it improved the tone dramatically.

Some speakers sound terrible when new, breaking them in can improve the tone up front without having to play through it a lot to get it broken in.

No pics today because nothing was done to the enclosure yesterday. Ran around getting the speaker, fiberglass insulation, silicone sealant and more box corners. I forgot that a cube has 8 corners, not four. Planning to paint the inside of the enclosure today, cut out the baffle, make the grille and mark the drill holes for mounting the speaker and handle. On Saturday, we'll tolex the enclosure, install the wiring and mount the baffle with speaker. At least, that's the plan.

Outside of Delta 12A speaker packaging. The speaker was secured in the expandable foam stuff, snug and well protected.

http://i1234.photobucket.com/albums/...296/spkr13.jpg



Rechecking the measurements for the baffle cutout. I originally had an Eminence Valtech 12" lying around and was going to use that before lucking into the Delta. We had first used that for the markings on the baffle cutout. He's remarking them here.

http://i1234.photobucket.com/albums/...296/spkr14.jpg


Planning to countersink the speaker so that its flush with the front of the baffle. I'm thinking that's what he's measuring here.

http://i1234.photobucket.com/albums/...296/spkr15.jpg

FWIW, the speakers on my cabs are front mounted, held in place by large brackets that bolt down.

Here are a couple of pix:



http://www.thefret.net/album.php?alb...achmentid=2278

http://www.thefret.net/album.php?alb...achmentid=2277

The grill is expanded metal held in place by sheet rock screws, counter sunk washers, and rubber feet (used as spacers).

@Tung: Thanks for the links! We're screwing it down as the speaker has 8 screw holes, on to the baffle plate. Thanks for the spacer idea, we're using scrap pine cut to size for the spacers and attaching velcro or upholstery tabs to them to secure the grille.

Sanding down the baffle, speaker hole already cut out. There's a story here, He had a fancy schmancy tool with a jig. We spent an hour yesterday figuring it out, but when he tried to use it, it was all wobbly. Went back to the old fashioned jigsaw to cut the hole.

http://i1234.photobucket.com/albums/...296/spkr16.jpg


Painted the internal ports with chalkboard paint.

http://i1234.photobucket.com/albums/...296/spkr17.jpg


Routing the countersink for the jackplate.

http://i1234.photobucket.com/albums/...296/spkr18.jpg


Finished countersink showing the jack plate (white). Incidentally, the jackplate was part of a 6" pvc pipe that he flattened with a heatgun between two heated tiles. Couldn't find an appropriate jackplate locally. Wondering if the plate will collect enough static electricity to add hum?


http://i1234.photobucket.com/albums/...296/spkr19.jpg

Painting the grille baffle.

http://i1234.photobucket.com/albums/...296/spkr20.jpg


Offering up the speaker and grille baffle for fabric clearances.

http://i1234.photobucket.com/albums/...296/spkr23.jpg


Mrs. Carpenter showing us how to place the piping.

http://i1234.photobucket.com/albums/...296/spkr22.jpg


Settled on the piping placement.

http://i1234.photobucket.com/albums/...296/spkr21.jpg

The blue glow of thunder from the amp requires a blue bolt of lightning, the only reason for piping. We cut the tolex and hung it out to sun warm. The grill cloth was also set out. Started wiring the speaker wire to the jackplate.

Attached the grille cloth to the baffle.

http://i1234.photobucket.com/albums/...296/spkr25.jpg


Dry fit into enclosure.

http://i1234.photobucket.com/albums/...296/spkr24.jpg

Starting the tolex job on the enclosure. Not liking the tolex choice here.

http://i1234.photobucket.com/albums/...296/spkr26.jpg


Finished tolex enclosure. Tolex looking ok----ish

http://i1234.photobucket.com/albums/...296/spkr27.jpg


Dry fit the speaker baffle and grille. Tolex looks fine.

http://i1234.photobucket.com/albums/...296/spkr28.jpg


Having some 'clearance' issues with the piping. The fit is a little too snug, so we decided to sleep on it. Not the piping, the issue, hoping a solution will come to us seeing we never did piping before. The amp is in the skybox!

Wired the jacks to the speaker tabs.

http://i1234.photobucket.com/albums/...296/spkr29.jpg


Installed jackplate.

http://i1234.photobucket.com/albums/...296/spkr30.jpg


Installed cab handle.

http://i1234.photobucket.com/albums/...296/spkr31.jpg

Had to remove the grille cloth, sand the sides down a little to get clearance for the piping and re-install the grille cloth. Installed cab corners. Rechecking the piping clearance.

http://i1234.photobucket.com/albums/...296/spkr32.jpg

That looks really, really nice! When are you going to be able to plug it in? :dude

All that remains is to install the insulation and speaker. We're taking our time with it cause I really didn't want the amp to get here and I couldn't plug it in. :) I'll probably take another amp when its finished to test it as an external additional cab though. I should have the amp by Monday next, so should be able to plug it in then. I'll record some clips.

It has been fun watching this come together. Probably more fun than building it has been!

So, do all the dogs in Port of Spain look like wires? :poke

:poke Are you sure thats a dog? :munch:

Its done !!!! (Barring tweaks)

Took my PRS and the Cube 60 over to test the cab. Sounds great. Quick and dirty pics.

Without the grille.

http://i1234.photobucket.com/albums/...houtgrille.jpg


With the grille.

http://i1234.photobucket.com/albums/...withgrille.jpg


Will take some more when the amp is in my grubby hands.

Very nice work! So, when are you starting up your speaker cabinet business? ;-)

1) SUH-WEET!! Very professional looking!

2) Clips???? :poke

That is sweet! How happy are you with the result?

Been using it constantly since I built it. So much so that i need to re-tolex it! Its broken in well, sounds warm. Suits me just fine!