AR.com DIY cabinet dimensions...and a question/suggestion

[kexodusc]

I've had several fellow AR.com members e-mail in the past week about the cabinet dimensions for the EFE DIY speaker design found here.

Madisound apparently suggests the user can increase the volume of the speaker to approximately 20 L to improve the bass response. Being a newbie to speaker building, I was a little hesitant to endorse a "mod" to the DIY design, so I decided to e-mail Ed himself to see what he had to say...

Ed's response was:

"Yes, it is true that if you increase the cabinet volume the bass will
increase. But as the bass increases you also give up a little of the
midrange tightness and purity that the DIY has become famous for. There is a
give and take for everything you change in speaker designing!

Most (not all) guys use the DIY in a surround system, usually adding a
subwoofer, therefore there is no need to have the DIY's produce more bass,
the sub takes care of the lower frequencies leaving the DIY to produce a
very clean midrange. Even without a sub, if the proper amount of insulation
is installed as per the instructions, the bass is very good for a small
bookshelf speaker. I prefer the smaller cabinet, thus the reason why I chose
it over a larger one when first designed.

Every designer has a certain goal in mind when designing a speaker, some
want as much bass as possible. I wanted a small speaker that produced a
pure, natural, tight and clean midrange, that is where 75% of the music is
produced. Good speaker balancing is the difference between a so so speaker
and a great speaker, I think the DIY has proven to be the latter because of
the reasons mentioned."

This is probably a no brainer for experienced builders...just thought I'd share.

This led me to thinking, how would it be to get ar.com to put together an FAQ for this speaker design? Any chance at all this could happen? It might save aspiring speaker builders and Ed himself a bit of time...not to mention being a valuable resource. Maybe there could be a wiki or a link or something?
Just a humble suggestion...please don't flame me..

[Swerd]

This led me to thinking, how would it be to get ar.com to put together an FAQ for this speaker design?

It sounds to me like you're just the guy to put this FAQ together . Keep notes of your initial ideas, mistakes, and observations as you build them. You could enter it as a How-To Article.

On the other hand, do we really need a FAQ list? Ed Frias has always taken the time to answer all our questions. He is both helpful and gracious, and it is fun to hear back from him. From my own limited experience, I would also say that you should do exactly as Ed says. As his response to your 20 liter question indicates, he has already thought of that modification and ruled it out for good reasons.

My total experience with these speakers is that I built one pair of standard Ed Frias design AR.coms myself. They are in the L6 cabinets made by Speaker City, have the updated crossover that lack the BBC dip, and I now have added 2 ohms extra resistance to the tweeter.

I also "consulted" for a 19-year old son and one of his friends as they built their AR.coms. I use quotes around the word consult because they didn't listen to me. It seems they were expert Parts Express catalog readers and knew they could tweak and improve them. They managed to reprove the saying "If it ain't broke, don't fix it". In an effort to get more bass, one made bigger cabinets (I don't know the volume), and the other substituted Peerless 8" drivers for the 6½" ones that Ed calls for and made a bigger cabinet. They don't sound bad, but they lost that pure, natural, tight & clean midrange that Ed described above.

Even though I think that Ed Frias's design is difficult to modify for the better, a FAQ list might encourage more people to try building these speakers for themselves. And that can't be bad.

Keep us up to date about your progress with your DIYs. I'm curious to know what you think of Wayne J's PeeCreeks.

[poneal]

It was a toss up for me between the PeeCreek and the AR.Com. I chose the AR.Com because of Ed's design and ease of access to him. I mean this guy has to get over 50 emails a day about this design and he answers them all. I'm also partial to the peerless sound and wanted to keep an all peeless design. The U-Pee (MorePee?) uses the much more expensive usher tweeter and that increases the toal cost of a 5 speaker system dramatically.

One thing I have learned. 45 degree edges are a bear to put together and even harder to get squared. Unless your a learned carpenter/woodworker do not use them unless you get someone to cut them for you that knows what they're doing. I am able to salvage all but the back of mine due to them not squaring up properly. So the lesson learned is for simplicity, use the butt joint.

Ed has also recommended that you flush mount the AR.Com so don't cheap out and baffle mount them. If you don't have a router rent one. Plus the flushing makes the speaker look professional.

Another lesson learned. Use scape wood/mdf to do the inital routing/flushing to make sure the measurements are correct before you route the real piece.

By the way, my wife loves the size of these boxes. It definitely has WAF (wife acceptance factor). They are kinda sexy looking if you ask me. Just the right size.

Well, there's my two cents....

[kexodusc]

Poneal: Do you recall the cuts and measurements you made to make the cabinets? Ed sent me the cabinet exterior dimensions, but I wasn't sure which size to make each side.

The way I did it was to surround the cabinet back with the top, bottom and sides and then have the front overlap those same pieces. I'm not sure if this is the "best" way, or if it even matter, but a book I have suggested it for another design...that way if you don't veneer the joint lines aren't terribly visible. Seemed to make sense.

Just curious if there's a better method, and if so, what makes it better? I did use the butt joint, though I was going to try a rabbet...someone talked me out of that and just suggested to use screws every 4 or 5 inches or so.

I can see the veneering being a bit troublesome...we'll see though. Could be awhile before I have a weekend at home again...

[EFE Speakers]

Hello guys,
Below are the specifications for the DIY cabinets including the inside dimensions as per original Speaker City cabinets. Thanks!

Ed Frias

DIY Cabinet specs

Outside dimensions are
13" high x 8 3/4" wide x 9 1/4" deep

Inside dimensions are
11 ½� high x 7 3/8� wide x 7 ¾ deep

Port size is 2" Dia. (ID) x 6" deep from rear surface.
Rear Port hole is centered (widthwise) and 3" from top to center of port.

Speaker input terminal hole is 1 15/16" Dia. It is countersunk 3/16" deep x 3" Dia. This can be changed if you desire another type or size speaker terminal. Rear Speaker terminal hole is centered (widthwise) and 3" from bottom to center of hole.

Front Tweeter hole is 3 5/16" in diameter. Front tweeter hole is also centered widthwise and also 3" from top of cabinet to center of hole. If you opt to countersink the tweeter, cut 1/8" deep x 4 1/8" Dia.

Front woofer hole is 5 5/8" Dia. If you opt to countersink, use 3/16" deep x 6 15/16" Dia.
Front woofer is centered 4 1/4" from bottom of cabinet.
Success to all!

Ed Frias
EFE TECHNOLOGY Speakers
efespeakers@commspeed.net

[EFE Speakers]

Don't know why the garbage was included with the inside dimensions, but I'll try again!


Inside dimensions:

11 1/2 high x 7 3/8 wide x 7 3/4 deep

[poneal]

This guy is everywhere... :-) Thanks, Ed.

[poneal]

Kexodus, I didn't use any screws or nails but just titebond glue. You must countersink your screws and then get some of that wood putty to cover the holes. Then you must sand it smooth. If its not smooth, then when you veneer it will show the imperfections, especially if using a darker color. The most important thing I have found is to sand, then sand, and then sand some more until its perfect. Don't put anything on it unitl you have sanded out all the imperfections. Then you can seal and paint, stain or whatever. Trust me on this one. Put the extra effort up front on the sanding because later on the down the line the imperfections don't go away but get worse. I know from experience on this one. LOL. I've never veneered but I think the peel and stick vinyl veneer would be a lot easier to do than real wood veneer. PE has about 4 colors to choose from. You can probably get it locally at home depot or paint store also. Probably a lot cheaper too. PE has raised there prices again so my new vendor is madisound. Have a good one. Paul.

[kexodusc]

Oh, I've done a fair bit of veneering in my day, and I have a decent woodworker helping me out too.
Real wood is the way to go...I just did my new audio cabinet in a nice birch veneer...I got a darn close match to my Paradigm's finish too...
You are right about sanding...the most important bit...I've learned that the hard way too. MDF is really easy to work with though.
My cabinets are already screwed together, howerver, but titebond might be an option for the next 2 pairs.
I'm tempted to take the router to round off some of the edges and spiff up the next batch of cabinets, we'll see how these turn out first.

I've worked with the PE veneer already on my parents MK III 12" sub. It is surprisingly nice, better than the crappy pictures on the website. Folks in the PE forums are right though, it's not the most durable, but subs don't usually get lots of wear and tear on them, so it should be good...

[poneal]

Ya, I had an old mahogony table that I got at an estate sale a month or so ago. All the finish worn off, legs falling off, rusted screws, water stains, etc. It was 3" thick with large heavy matching legs made in the philippines. I brought that puppy back to life. I rounded the sharp edges and what a difference it made. Just made the living room table more appealing. My wife wanted to stain but I put the foot down and said no staining whatsoever. I clear coated it using that polycrylic and it came out beautiful. She was really impressed. The table looks brand new. I bought it for $30.00. In a store I'm sure it would cost upwards of $500.00. I would round if I were you. MDF rounds really well and I think it would make it more appealing. Just my two cents. I'm just glad I only have to work for 18 more minutes and then its home to work on the project some more. Let's keep in touch and let each other know how our project is going. Later, Paul.

[Drop Drive]

(Please bear with me as I know little about speakers and even less about woodworking.)

Outside dimensions are 13" high x 8 3/4" wide x 9 1/4" deep
Inside dimensions are 11 1/2 high x 7 3/8 wide x 7 3/4 deep

I gather that these plans call for 3/4" thick material such as MDF for all six sides? If so, isn't one of the width measurements off by 1/8"? Which one is correct? (This is nitpicky, but if I'm going to do it, I might as well do it exactly right.)

Port size is 2" Dia. (ID) x 6" deep from rear surface.
Rear Port hole is centered (widthwise) and 3" from top to center of port.

I don't understand this bit. What is a port? What is "(ID)"? How can something be 6" deep from the (inner? outer?) rear surface--won't it be right in the inner cavity? And is a "rear port hole" simply---from a woodworking perspective, anyway---a hole in the rear panel?

Speaker input terminal hole is 1 15/16" Dia. It is countersunk 3/16" deep x 3" Dia.

A Google search tells me that countersinking is like making a "starter hole" for screws, but that doesn't seem to be the case here. Should I just think of it as a cylindrical hole that doesn't go all the way through? I suppose then that the countersink "hole" should be on the outside?

Seems like one can choose to countersink the tweeter and woofer holes. Will these again be from the outside? Are there any advantages or disadvantages apart from aesthetic ones?

poneal, do you find Titebond glue alone strong enough, or did you use L-shaped brackets on the inside too?

And thanks to Jim Clark for pointing the AR.com DIYs out to me.

Peter

[poneal]

(Please bear with me as I know little about speakers and even less about woodworking.)


I gather that these plans call for 3/4" thick material such as MDF for all six sides? If so, isn't one of the width measurements off by 1/8"? Which one is correct? (This is nitpicky, but if I'm going to do it, I might as well do it exactly right.)



I don't understand this bit. What is a port? What is "(ID)"? How can something be 6" deep from the (inner? outer?) rear surface--won't it be right in the inner cavity? And is a "rear port hole" simply---from a woodworking perspective, anyway---a hole in the rear panel?



A Google search tells me that countersinking is like making a "starter hole" for screws, but that doesn't seem to be the case here. Should I just think of it as a cylindrical hole that doesn't go all the way through? I suppose then that the countersink "hole" should be on the outside?

Seems like one can choose to countersink the tweeter and woofer holes. Will these again be from the outside? Are there any advantages or disadvantages apart from aesthetic ones?

poneal, do you find Titebond glue alone strong enough, or did you use L-shaped brackets on the inside too?

And thanks to Jim Clark for pointing the AR.com DIYs out to me.

Peter

1) Ya, looks like the width is off. Instead of 7 3/8 I think it should be 7 1/4" and yes its 3/4" MDF
2) ID=Inside Diameter, So it's 6" long and 2" ID heres a link to one:
http://www.partsexpress.com/pe/showd...number=260-387
u just discard the extension and you have a 6" long port.
3) Countersunk means flush mounted. So you have a circular hole the diameter of the driver and then you make this hole however deep the lip is on the driver so that when you mount the driver it will be flush with the front baffle/mdf panel. You also need to make a smaller hole for the rear driver basket/magnet to fit through. The best way to do this is to use a router with a 1/4" straight bit and circle jig attached to the router so you get exact circles the diameter you need. Flush mouting is important because it affects how the speaker will sound. Without going into detail (which I wouldn't know anyway) the baffle step correction that ed has built into the xover would be off.
4) The titebond II glue has worked well for me. I have routed and sanded the glued boxes and they have not come apart. I did not use any screws or nails, just glue. I'm still priming/sanding/finishing the boxes. I will not be done for about 2-3 more weeks.

They sell circle jigs at Parts Express and other places. Hope this helps you out. Paul.

[kexodusc]

Just to add to Paul's excellent comments...There'd be some nasty diffraction at some frequencies really distorting the smooth frequency response, usually if you don't countersink it's recommended you use diffraction rings...lots of brand name speakers use these (Paradigm, PSB, Polk, B&W, Wharfedale, etc) and I'm starting to realize this is quite often a cost saving shortcut.

[poneal]

The previous night I had glued the last back baffle onto the last box. Got off work, started taking off the wood clamps and got all but one off when the weight of the last one caused it to fall off the workbench. Ya, duh on me. I was thinking, man another box, another week's setback. Well, it stayed together just fine. It did have a 1/4" dent on one side about 1/2" in diameter that I was able to fill with wood putty.

So why am I telling you this. One of the previous questions asked if I just used glue and I stated yes that's all. Well this box dropped 5' and stayed together with no problems using just glue. To me this indicates that a good glue does work without using nails/screws. Just my two cents of early morning rattling. Have a good one. Paul.

[kexodusc]

OH, man...that's sucks...Nothing bondo can't take care of though.
The race is on Paul, in the next 2 weeks I'll be in a new house in Canada somewhere...what are the odds I can get the speakers veneered, stained, and assembled before the movers come next Tuesday? (slim to none...gonna have to pack them)
Wood glue is pretty tough. I built a cheapo audio rack out of 3/4 MDF a few years that I climb on quite frequently to open a window...I tend to cause it to shift from side to side and front to back, but it doesn't crack or break or anything. If it can support my 175lbs, it'll hold a speaker together.

[poneal]

but it's gonna be tough to finish because I'm sure your working and packing, etc. Wow, then you gotta set up the new household but it does give you an opportunity to redo the HT/living room layout. Of course then you gotta do the SPL calibration thing and all that good stuff. I wish you luck but I know that your gonna be one tired camper after moving.

I'm cutting and glueing the grills this Sunday (almost forgot about them bad boys). Then I need to drill the guide holes for them before I continue priming, sanding, painting, etc. Ed didn't leave us a lot of room on the woofer edges for grills (especiall since I used a 3/8" roundover on all edges. That leaves about 5/8" of an inch so I'm planning on making them 1/2" wide and 1/4" thick using those small grill guides from PE that just happend to be 1/4" long. Using red oak so hopefully they will be strong enough because they are pretty thin. Well, I better quit messing around here and get back to work. Talk to ya later. Have a good one, Paul.

[kexodusc]

Errr....grills...yeah, forgot about those too....I talked to my cousin and sent him the design...he's suggesting I use the magnets that you can buy at most DIY websites, sink them into the MDF and cover them with the veneer...I might try that.
My fiancee's looking at houses as I type, her and her parents have a few narrowed down...I've left instructions for 2 rooms so I can reproduce my studio ( I play some instruments) and HT...since we don't have kids yet this shouldn't be a problem.

You're right though, I just ran speaker wires a few months back through the walls to hide them...that was a tedious job...now I gotta do it again.

This whole new job thing happened so fast in the last 2 weeks.
I figure I shoudl have these done by the end of September if everything goes smoothly though...October for sure!!! Gonna have to buy a plunge router though, can't take my neighbor with me!!!

[poneal]

find a new friend with one. I borrowed a co-workers plunge router. I haven't run my wires in-wall yet because it's just to darn hot, but I do intend to do that when it starts to cool down here in south texas. I've got some many projects around the house to do that I can't keep up withem all. Ah well, slowly but surely they get done. Are you self moving or is the new company moving you? Later, Paul.

[Drop Drive]

Front Tweeter hole is 3 5/16" in diameter.
If you opt to countersink the tweeter, cut 1/8" deep x 4 1/8" Dia.

The magnet diameter of the PEERLESS 812687 1" DOME TWEETER is 72mm (scroll down a bit), which is roughly 2 7/8", so why is the hole diameter 3 5/16"? Am I missing something? (The countersink diameter of 4 1/8" is the same as the "overall diameter" given on the Parts Express page (first link above).)

Front tweeter hole is also centered widthwise and also 3" from top of cabinet to center of hole.
Front woofer is centered 4 1/4" from bottom of cabinet.

Are these measurements from the exterior or the interior? Is the distance between the centers precisely 13 - 3 - 4 1/4 = 5 3/4"?

Three more questions: (1) Is there any value in making the front panel (the baffle?) out of HDF, or 1" MDF, or even 1" HDF? (2) Is the front panel supposed to be detachable? Or does one work though the speaker holes, in construction and repair? (3) Would not having a grill degrade sound quality?

Many thanks. I'd be happy to write up people's answers should an FAQ ever get started. ---Peter

[EFE Speakers]

For all concerned,
The measurements given for hole placement is measured from the exterior of the cabinet. As far as actual hole sizes, those were the original hole sizes that came in the L-6 cabinets from Speaker City, not made exactly for the Peerless drivers. Measure the exact size of the Peerless drivers and make the holes in your cabinets just a bit larger, be sure to make notches for the tweeter wire terminals. If the inner dimensions I gave were 1/8 inch off, no big deal, just make sure to keep the original inside volume of the cabinet correct. As stated several times, you can enlarge the cabinet and gain more bass, but if you desire the speakers to produce a very clean tight midrange, build them to the original specified dimensions. Success!

Ed Frias
EFE TECHNOLOGY Speakers

[poneal]

For all concerned,
The measurements given for hole placement is measured from the exterior of the cabinet. As far as actual hole sizes, those were the original hole sizes that came in the L-6 cabinets from Speaker City, not made exactly for the Peerless drivers. Measure the exact size of the Peerless drivers and make the holes in your cabinets just a bit larger, be sure to make notches for the tweeter wire terminals. If the inner dimensions I gave were 1/8 inch off, no big deal, just make sure to keep the original inside volume of the cabinet correct. As stated several times, you can enlarge the cabinet and gain more bass, but if you desire the speakers to produce a very clean tight midrange, build them to the original specified dimensions. Success!

Ed Frias
EFE TECHNOLOGY Speakers

Ed, I'm nearing completion of my boxes and will order the drivers tomorrow. I already have the latest crossovers preassembled from madisound and this is where my question lies. When I order my drivers should I ask for (5) 2 ohm resisitors that attach to the positive terminal of the tweeter? Maybe an assortment? Or none at all? The reason for 5 is because I have built 5 boxes. Thanks, Paul.

[EFE Speakers]

Yes, 5 ohm resistors are on the board and 2 ohm resistors should be added at the tweeters!

I believe the other posting where you thought the poster used 20 ohm resistors just appeared that way, but he accidently enlarged the O on ohms, so it read like 2Ohms rather than 2ohms. 2 ohm resistors should be the value to start off with, you can go up or down from there! Look forward to hearing how they come out!

Ed Frias
EFE TECHNOLOGY Speakers

[dave_bullet]

Yes - sorry about the misleading post on the resistor to pad down the tweeter. I must pay "ohmage" to Ed for clarifying that (sorry - I couldn't resist that).

Anway - the good news is my AR.com DIY kit arrived from Madisound today (great service - 5 days from order to shipping and I live on the other side of the world!)

The question is - I have a project to build a CD bookcase.... or the AR.com DIYs - gee what should I start - easy choice really (CDs can just stay on the floor for a little longer :-)

I'm going to build the AR.com DIYs in a tower with a shelf in the middle to cut the volume the woofer sees to the planned size. (I'm tired of stands). I must admit - I'm impressed with the solidity of the tweeters. With excitement, comes some pride - so I'll be sure to post my pictures of construction along the way (somewhere....)

Cheers,
Dave.

[kexodusc]

I'm going to build the AR.com DIYs in a tower with a shelf in the middle to cut the volume the woofer sees to the planned size. (I'm tired of stands).

Dave, let me know how that turns out...I've already planned out my floorstander Ar.com's for my next project as soon as I'm finished the bookshelfs....just curious, what height are you using? I can't remember exactly, but I think I picked 26" height in addition to the 13" for an even 39". I read a few posts or comments where Ed's used 24" stands for them.

I've decided on a sliding shelf to allow me to fill the lower cabinet with sand or cat litter for loading.

I'm also thought about modeling a smaller ar.com using the Peerless 850108, 5-1/2" woofer for surrounds, but I might just cut down the cabinet depth and height a bit, and lose some bass response while keeping the 6-1/2" woofer to make them a bit more wall mount-friendly...they'd be cutoff at 80 Hz or so anyway by the processor/receiver. Save me from having to design a new crossover...we'll see...might be best just to build 2 more bookshelfs?

Good luck.

[dave_bullet]

I'm going for approx 35.5" high. I have a low couch and that height would put the tweeters at my ear level (which is usually recommended for floorstanders). eg. the top part of the cabinet will look exactly like a bookshelf AR.com DIY eg. 3" tweeter centre from top of cabinet, woofer approx 6mm from tweeter etc...

What I find hilarious is most manufacturers will make the lower end towers "shorter" to make their models through the range look bigger and justify the increase in price. If I made speakers......

PS: - don't forget to allow for feet in your tower design - these can be 1"+ if you use spikes

I like the idea of a shelf on an angle. Help break up panel resonances.

I notice with the Madisound kit they give you foam for the walls. Should you still stuff with batting / acousta-stuff? If it helps absorb unwanted midrange from escaping from the port - fine, but if it is just to make the box appear bigger for the woofer (which stuffing does by roughly10%) , I can do that by moving my partition down the cabinet.

Cheers,
David.