# Newbie Questions



## abrumlev (Sep 21, 2009)

I have some experience building subwoofer enclosures but speakers are my new adventure.
I got the Speaker Building 201 book for my birthday but with college classes overwhelming me I haven't had time to really get down and learn it.

Spring break is in three weeks and I need to plan ahead and design some sets of speakers I can build over break. I'm looking to do some cheap bookshelves and some taller towers (3 ways). I'm looking to spend around ~$40-50 for the bookshelves and around 150-200 for the towers without cost of wood, glue..etc. I have sufficient wood working skills to build most projects.

Does anyone have any suggestions or links to some good beginner set ups that will be efficient? 

I'm in college so they'll see mostly loud music duty with trance/hip hop/rock music and occasionally end up in my little "theater" in the basement.

Teach me...I wanna learn!!! :bigsmile:


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## jackfish (Dec 27, 2006)

Indignias for the bookshelves and TriTrix for the towers. You can get the entire TriTrix kit for $200.


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## fbov (Aug 28, 2008)

Sorry, but this calls for my basic tradeoff discussion. 

Quite frquently, one is faced with a number of mutually exclusive desires; pick this and you can't have that. It usually comes down to Quality, Cost and Delivery. This is one case where you can have 2 of 3
- used for "loud music duty with trance/hip hop/rock music "
- cost "around ~$40-50 for the bookshelves and around 150-200 for the towers"
- and since you have SB201, you expect them to sound really good. 
You want a high quality speaker that plays really loud... that's not cheap!

The Tritrix at $200/pair including knock down MDF enclosures is a very special special offers that fits most of your needs - but they will not play as loud as speakers costing twice as much. They are also available without MDF and in CC configurations so I'd suggest considering a set of 5. 

Alternatively, the Insignia project is one of several I've seen that deliver great value, but are only available for a limited time. My $80 pair was Madisound's RB-1's this time last year. Frankly, I'm surprised PE is keeping the TriTrix in stock; they were out last week. 

One caveat is that they are true 4 ohm speakers, and some amps don't like that....

And if you'd like more choices, I can obfuscate with the best of them. 

Frank


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## abrumlev (Sep 21, 2009)

Oh I completely understand the tradeoffs. Coming from the performance auto background I know firsthand the correlation between the big 3.

I've glanced at the Tritrix and liked what I saw but I'm interested in building the cabs myself and seeing the price for just the components, I feel for the price I could find a better design.

I've seen plenty of project ideas and guidelines on sites such as HTguide but it seems that when I find one I like, the speakers are discontinued or there is a lack of detailed explanation on how to construct them.

How bout the Natalie P's? Looks like the speakers/XOver components will run around 300 which I think i could swing...and hold off on the bookshelves (were going to be a gift to my aunt who bought me the Speaker201 book).

Continue to obfuscate...it distracts me from my organic chemistry quiz tomorrow!


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## 1Michael (Nov 2, 2006)

"I've glanced at the Tritrix and liked what I saw but I'm interested in building the cabs myself and seeing the price for just the components, I feel for the price I could find a better design."

For that price you are Not going to find a better deal...period.
The NatP's are going to cost more than you have stated for a budget and they require an amp that is stable for a 4 Ohm load.

For $300 you can build these which were made for your kind of music. http://www.hometheatershack.com/forums/diy-speakers/18814-budget-8-dayton-classic-mtm-rocks.html

Outside of that, stick with the Tritrix.


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## abrumlev (Sep 21, 2009)

Those are just baseline numbers. If it takes another month of two to save the money to build a better speaker then I can do that.

Chances are I will build the enclosures over my spring break and then install everything weeks later when I have time. 

Thanks for the link! I'll check those out also.


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## abrumlev (Sep 21, 2009)

I think I'm gonna go with that Dayton 8 Setup you posted. It's coming to a little over 200 for parts including the port tubes and binding posts. Im going to use baltic birch $30 per 4'x8' sheet from Lowes.

Can't wait to start it. First true speaker project. Gotta keep myself busy on spring break since I'm not going to FL with all the drunk college kids. Also going to build enclosures for my 15" Titanic MKIII and 12" Shiva X.


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## fbov (Aug 28, 2008)

First, my condolenscens on O-chem. I managed to avoid it, but my son tells me it's was nothing compared with physical chemistry. Now let's get you some choices....
http://techtalk.parts-express.com/showthread.php?t=211558

This is the master list of DIY design threads (as opposed to build threads). You have far more options here than what you found in HTGuide's Mission Accomplished section. Knowing you understand the tradeoffs, let me give you a bit of background on the people who contribute deisgn. There is a lot of talent, but a few of these folks are true audio nuts. Know what you want and stick to it and you'll be happy. 

Many of the designs assume basic familiarity. The minimum needed to define a speaker design are:
- drivers
- driver mounting geometry on the baffle (front of speaker)
- crossover circuit diagram

Drivers have 2 key responses, sound level output vs frequency and impendance vs frequency, used for XO design, and tons of other characteristics like distortion, power handling, etc. 

Driver mounting geometry addresses driver response that varies with mounting. Bass response varies depending on how big a space the speaker's sound fills. A point source radiates into a 4-pi solid angle. Put it on a wall and it radiates the same power into a 2-pi solid angle, so it sounds louder, especially at low frequencies. At the high frequencies, edges matter. Like edges on drivers (thus all the flush mounting) and edges of the baffle. 

You want these geometric factors set as well as drivers selected and measured before you start XO design. I'll assume you can read a circuit and having read SB201, you likely know more about this end than I do. The key is that one only needs to specify these 3 things to define a speaker design. 

If you know what to do with that data. 

Some designers only give you bare bones, others basic instructions down to those who sell screwdriver kits (i.e. you only need 1 tool for assy.). You mention NatPs, so I'll use that design definition as an example. It helps I built an LCR set - my avatar.

NatPs are very similar to Tritrix; both are 2-way MTMs. However, one has larger, higher power, lower distortion drivers so it costs more but plays cleaner, louder. Figure ~$425 for a pair, drivers and XO only, and be prepared for a complex XO design, something like 15 components. You will get a speaker that's capable of 105dB @ 1m @ 100W, has great transient response, and is capable of reaching 30Hz (with the appropriate tradeoffs). 

The NatP design thread is one of the more complete, down to showing you the box and port, and the components have proven very popular; there are 5 XO designs for these drivers in this geometry, plus on-wall/in-wall XO - the base designs assume 4-pi applications. 

But, it's out of your price range, and I would take the impedance warning seriously; they do dip below 4 ohms even if my amp hasn't complained. 

I discuss it in detail as an example of a fully-documented _design thread _for a design with lots of _build threads_. Substitute drivers, driver geometry and XO circuit details and this is how you build any DIY design. Jon just shows all the steps. 

I like buggers 8" MTM design; cheap and loud if not as refined - you get 2 out of 3, just not the same 2 as the Tritrix. At the same time, I've found that the "quality" side matters most to me over the long term. I also find that I don't play loud very often, but then I started buying gas when it under $0.30/gal. 

If loud is important, build to it, as the one thing that can damage speakers is being driven to loud even by a low-power amp. If not, I'd lean towards quality, especially if additional funds become available.

Have fun,
Frank


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## abrumlev (Sep 21, 2009)

Wow...I appreciate the detailed response Frank

Like I said...I'm 21 years old (started buying gas at ~1.60's, gotta say I'm jealous ). Right now...loud is better but this will be far from my last DIY project. Ideally I'll be able to do a halfway decent job in others' eyes with the 8" MTM that I'll eventually be able to progress into the more detailed quality builds that all of you guys have the knowledge to build.

I'll probably post up a dedicated build thread especially for help designing the crossovers.

Thanks again everyone!


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## fbov (Aug 28, 2008)

You're the age I was when I sold my reel-to-reel tape deck and 65 1800' tapes of cataloged recordings to raise the money for a pair of Advent loudspeakers. The NatP's replaced those Advents. 

Keep in mind that the "quality" of the sound is in predominantly in the design you choose. Appearance is where experience shows. At this stage you don't want to be designing XOs, and buggers design should include an XO circuit diagram. I see pictures of one, but his build thread link's not going through for me. 

You haven't committed yet, so keep researching. I bet there are other designs that favor cheap and loud...

Have fun,
Frank


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## abrumlev (Sep 21, 2009)

Yeah I'm working as much as possible right now, I just don't make squat for money fixing exercise equipment at the school gym. Some of my older guitar equipment is on its way out and I'll be building some car subwoofer enclosures to finance this. 

I meant layout, not design for the crossovers, oops. 

I've been looking around for a detailed, comprehensive guide to building some speakers and I need to commit to one soon. If I don't like how these speakers turn out in appearance or sound quality, I'll probably sell them to my college buddies who will be blown out of the water compared to their Bose Ipod Dock speakers.

-Andy

Oh and is there an article on driver break-in out there someone knows of? Or just plain advice?


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## lsiberian (Mar 24, 2009)

DIY speakers are a lot of work however drivers are cheap. Building crossovers is probably the greatest challenge. If you can do that then you got it made. Do realize speakers require more dampening and bracing than a subwoofer. You can also go active, but the external cost is greater. 

Still a pair of speaker drivers for a hi-fidelity design is well below your budget.


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## 1Michael (Nov 2, 2006)

I fixed that website link and included the Xover picture. You can make these smaller and sealed if you like and you could even shorten them and make them sealed bookshelf speakers.


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## fbov (Aug 28, 2008)

abrumlev said:


> ... I've been looking around for a detailed, comprehensive guide to building some speakers ...
> ...Oh and is there an article on driver break-in out there someone knows of? Or just plain advice?


Driver break-in? See the third sticky thread.

You want a detailed comprehensive guide? Wasn't that SB201??

Maybe it's because I started building things as a kid, but I didn't need a guide, I just built boxes. It really is that easy. The only big things to watch for are
- maintain baffle width, so this has to be the width of your box
- maintain driver locations on the baffle.

The one thing I haven't brought up is bass alignment and box size optimization. You can just build to the design specs - box volume and port length/diamter - but this is one area where you have some freedom as the XO isn't involved at frequencies below 100Hz. Those T/S parameters I mentioned earlier allow you to simulate bass response in whatever size box you'd like. It's the reason for my parenthetical note to my NatP 30Hz response - I optimized a ported box for that extension, at the price of destroying the drivers with a 100W 20Hz input. Needless to say, I never expect them to see a sustained 20Hz sine wave at rated power, but I do enjoy the subsonics. 

Two popular box simulators are Unibox and WinISD; I use the former. Here's a link to speaker design tools. 
http://www.pvconsultants.com/audio/frdgroup.htm

To summarize, 
- build a box of the required volume. 
- mount the drivers in the right places
- build and connect the XO 
- listen to it

There are things I call "best practices."
- flush mount drivers (easy if you have a router and circle jig to cut the holes)
- relieve the rear of the woofer hole (chamfer the inside of the hole; see the NatP desing thread for an example)
- Install ~1" of accoustic absorbant on the inner walls (carpet padding is a cheap option)
- if ported, tweak the port length until the bass sounds best
- if sealed, add accoustic fill (pillow stuffing) until the bass sounds best
- experiment with room positions, but never put a free-standing design close to a wall (or vis versa)

As long as you can cut and glue 6 pieces of MDF to form a closed box, you can make a speaker. It's really not that hard, but I also may be missing something, so keep asking!

Frank


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## fbov (Aug 28, 2008)

buggers said:


> I fixed that website link and included the Xover picture. You can make these smaller and sealed if you like and you could even shorten them and make them sealed bookshelf speakers.


Nice site. I see everything the OP needs for the ported version, except perhaps an interior photo during the build (I don't always take pictures while building, either). It's not always obvious where cross braces go...

Well done!
Frank


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## abrumlev (Sep 21, 2009)

I could say I'm OCD in a way before I start a project for the first time. When I say a guideline to building a speaker, I mean a walkthrough to the exact specs that the original designer and builder had in mind with pictures or descriptions.

Ever since I started doing car part installs, I have found DIY Walkthroughs for almost all the major projects I've taken up from replacing brake calipers, to installing turbo's and suspension parts. After the first time I do it I'm comfortable to do it without the help. It's a "safety blanket" per say for the first time I try something I feel unsure about. I'm to the point with subwoofers I can comfortably knock out an enclosure and design in a weekend, but speakers on the other hand I'm new to.

To ensure no mistakes, I'm going to build to exact specs, flush mount, etc. 

Where do you guys recommend getting the egg foam or acoustafill?


I think he explains well enough to guesstimate where the bracing goes. Some horizontal bracing with 3" holes in them to help with air flow.


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## 1Michael (Nov 2, 2006)

1. Will you be using a subwoofer?
2. Do you want to build the full size tower ( requires at least 2 sheets 4'x8'), or do you want it to be more of a bookshelf size?
I do not have specific step by step instructions. Just remember, this is only a box with some bracing and holes in it. You can not change the width. The height and depth are negotiable. And like I said these will cost $300 not $200...


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## abrumlev (Sep 21, 2009)

90% Sure I won't be based on what was said in your build thread about the good bass response.

Yep full size. I love the look. I have some old 1987 Sherwood S2125's right now. Excuse the blacklights...someone was living in the "theater area" for a few months  










Half of the drivers are blown on each.

I'll draw up the front baffle and post it up here. For some help on the crossover set up I think I'm gonna talk to my physics teacher as the lecture before mine is on electrical and sound. 

Yup I got the parts list ordered. Right around $220 shipped.The only thing I noticed that wasn't in there was binding posts. Does this sound right, buggers?


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## 1Michael (Nov 2, 2006)

Post your order so we can have a look at it.


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## fbov (Aug 28, 2008)

Get binding posts, and post your order list.

Fiber fill is not the same as surface absorbers is not the same as damping. Egg crate is a surface treatment while fill is a volume treatment. Both absorb sound energy from the air, just at different places. Damping is what you put on surfaces to prevent them from vibrating. In some products, damping material is combined with surface treatment.

If you've build a sub, you have built a speaker. You can't expect DIYers to do professional-grade installation instructions with no financial incentive. You get what you pay for. The NatP design thread hits on all the major elements, and my build thread shows you what a tower looks like. Just be aware that I did a lot of learning early, then tried to put in everything, since the box was the only part that was wholely mine to design. 
http://www.htguide.com/forum/showthread.php4?t=30536

I should add a best practice; when using window-pane bracing, make sure you have at least 50% void area. 

By the way, don't take any of this as criticism, but rather a reality check. You've got an excellent process that will do you in good stead in the future. And if you've blown those speakers, you need something that plays loud, and the amp to drive it. Distortion kills speakers, but distortion also sounds "louder." The goal is a sound level where you can't hear yourself think, but it doesn't sound _loud_ per se. 

Have fun,
Frank


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## abrumlev (Sep 21, 2009)

Here we are guys.










And no worries, the carpet is NOT for the towers :sarcastic: . Joint order for my buddy who does car audio installs.

Frank: I've learned that disregarding advice from experienced people tends to be an immature/amateur mistake. Everything you've said has been duly noted and will be referred to often.

The sherwoods were used in my high school's gym so all of the blown speakers aren't my doing...yet :T

Once I survive the rest of the school week I'll try to get some drawings up and see what you guys think (if you guys don't mind doling out more constructive criticism).

On to circular motion and centripetal acceleration :huh: ...Later guys 

Andy


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## fbov (Aug 28, 2008)

buggers response went in his build thread.
http://www.hometheatershack.com/for...et-8-dayton-classic-mtm-rocks.html#post240363


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## 1Michael (Nov 2, 2006)

It looks good except there is one part missing which was missing from the original parts list
027-348 Dayton 22uF 100V Non-Polarized Capacitor 2Each, to parallel with the 50uf 100v, to make a total of 72uf 100v. Now I remember when I built these I found that discrepancy but I forgot to add it into the list.
Add 1 brace behind the tweeter, 1 just below the lower woof, and 2 more lower down, Just remember the port goes between #2 and #3 brace or you can locate it on the bottom if you wish, or on the back for that matter.

For the Xover the top line is positive, lower is negative. Lay out the parts exactly as you see it in the diagram, twist leads together, Take a picture and let us look at it before you solder

The baffle is double thick, I used MDF for the inner piece, ply on the outside, 4 feet tall. That means the absolute max height of this box is 4 feet. There is a top and bottom piece to a box right? How are you going to put the box together? Put the sides together then slap the top and bottom on? Or will the top and bottom be "inside'' of the side pieces? Its up to you so You Will Have To calculate the dimensions of those pieces. It does not matter so...


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## abrumlev (Sep 21, 2009)

K I'll get that part ordered. Thanks for the heads up.

I'll get my plans drawn out this weekend and maybe have my dad sketch them out in AutoCAD.

I'll be using baltic birch and probably MDF on the inner baffle like you. I like having one piece front baffles for cleanliness so I'll probably have the Top and bottom be "inside" the side pieces.

I'll take as much advice as possible to make these quality.

Thanks guys.


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## 1Michael (Nov 2, 2006)

I was supposed to say in the above post there are 4 braces. Also you can add a hardwood top to the box after its all put together. Some walmarts have solid oak hardwood tv dinner type trays, you know the kind that is a stand for around $8.50 each. Can't beat that price. I use them on all of my builds.


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## abrumlev (Sep 21, 2009)

Cool. I'll check those out.


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## gvimhoof (Aug 25, 2009)

fbov said:


> You're the age I was when I sold my reel-to-reel tape deck and 65 1800' tapes of cataloged recordings to raise the money for a pair of Advent loudspeakers. The NatP's replaced those Advents.
> 
> Have fun,
> Frank


I'm really happy that no one asked what a reel-to-reel tape deck is. I just heard an announcer on NPR ask a studio guest if perestroika happened in the '70's. Seriously...:rolleyesno:


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## abrumlev (Sep 21, 2009)

Well I was getting frustrated with all of the parts not falling over or moving around on me but here's my first try at laying out this crossover. I layed it out based on Bugger's layout but flipped the tweeter xover upside down so the two negative wires would come into one. Top line is woofer and bottom is tweeter.

The wood is about 5"x7" so its either going to go in the base that I'll be adding or sit on the bottom of the enclosure.

Critique away.


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## 1Michael (Nov 2, 2006)

The Xover looks good. Now you can twist all the connections together, then hook up the drivers and listen to it at a "LOW" level to ensure that you get sound. Of course don't touch it with juice running around.
Solder before mounting it to the board, then on the woofer Xover pull the two red inductors as far apart as you can, then mount the puppies:T


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## fbov (Aug 28, 2008)

+1 save for coil spacing. You've used the preferred orientations, so the coils will have minimal interaction even if close. However, it never hurts to space them farther apart... but you do get a far larger XO board that's harder to mount. It's another tradeoff...

I've used hot melt glue and tie wraps to mount components to the board. The only advantage I see is the latter are easier to disassemble.


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## abrumlev (Sep 21, 2009)

Here we are guys. Looks okay for my first time but I think it'll do the trick.

Thanks for the guidance. The tower builds will start Sunday/Monday or whenever I can pick up my Uncles table saw and router.

Pics


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## 1Michael (Nov 2, 2006)

Have you hooked them up to the drivers yet?


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## abrumlev (Sep 21, 2009)

Yes sir I have.

Everything sounded alright. Both woofers were playing the same freq's and the tweeter sounded nice and clean.


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## fbov (Aug 28, 2008)

Wait until you get them in the boxes... No speaker sounds good in free air!


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## abrumlev (Sep 21, 2009)

I CANNOT wait to hear these things. This past week of midterms I've been staring at the box of the drivers and my background is pictures of other peoples' finished products. 

I'm going to go over the design with my dad and he's going to draw it up on Autocad for me...gotta love engineers...and dads! haha

Does anyone have bad experience using the 3/4 Baltic birch from Lowes/HD. I was going to just stain the bb instead of veneering/flat paint.


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## 1Michael (Nov 2, 2006)

The BB from Lowes is fine, or the oak ply for that matter. Which ever you like.


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## fbov (Aug 28, 2008)

abrumlev said:


> ...Does anyone have bad experience using the 3/4 Baltic birch from Lowes/HD...


In my area, the 3/4" birch ply at Lowes/HD is NOT what's known as Baltic birch or Russian birch. The latter has many thin plies and usual comes in a ~5x5' format, not 4x8', and only at the local woodworker's lumber yard. If you see thin surface plys and thick center plies, it's plain old plywood with a birch veneer. That's not bad, per se, but it's not BB.

Frank


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## 1Michael (Nov 2, 2006)

So whats the status? Let's see some more build pictures.


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## abrumlev (Sep 21, 2009)

Whoops! Sorry guys I've been swamped with school. I got them both built over spring break. It was a bit humid so some of the boards got warped. I was hoping to not use any screws but unfortunately didn't work out that way. 

For the time being I didn't stain or finish it. The horrible news is my Denon AVR-785 died on me the other night during a Little 500 party (Indiana University). 


























I'm a little mad I didn't take pictures as I built them but I didn't want my blackberry covered in sawdust or glue and my point and shoot's batteries died the weekend before.

I love how they sound. Nice and crisp compared to anything else I have.


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## lsiberian (Mar 24, 2009)

abrumlev said:


> Whoops! Sorry guys I've been swamped with school. I got them both built over spring break. It was a bit humid so some of the boards got warped. I was hoping to not use any screws but unfortunately didn't work out that way.
> 
> For the time being I didn't stain or finish it. The horrible news is my Denon AVR-785 died on me the other night during a Little 500 party (Indiana University).
> 
> ...


Anyway you can round over the front left and right edges.


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## fbov (Aug 28, 2008)

Screws are in the way... Can you pull them?

One of the key design criteria is baffle edge geometry. The sharp edge you have is worst-case for diffraction. A big roundover or chamfer, as specified in the design thread, is required if the crossover is to deal with the diffraction properly. 

Look closely at my avatar and you'll see how I put a 3/4" chamfer on the baffle edge between the woofers. Most find it easiest to extend the roundover/chamfer full length, but my design would only accomodate the minimum needed. 

Nice work otherwise. How do you plan to finish?

Frank


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## 1Michael (Nov 2, 2006)

Yes, at least a 1/2 inch round over. How do they sound:foottap: How much did they cost? Would you recommend these to others?


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## abrumlev (Sep 21, 2009)

Sorry guys...school, mono, and my job all caught up with me and I just now remembered about this forum and all the help you guys provided. 

My receiver crashed on me about 2 weeks after I "finished" them so I have just enough time on them to break them in. They sound very good, not as much bass as I thought it was going to be but I'm a basshead so overall I think they're great. Paired up with my 15" Dayton Titanic and rear audio pro speakers I really like how crisp and clear the sound is. 

Its been awhile since I finished them and I don't have the invoice anymore. Off the top of my head the drivers and crossover components were around $250 then $100 for the birch.

I have yet to finish them. I was going to try to pull out those screws and round over the front edges and finish up soldering in the speakers (they just have female connectors on the wiring now).

I'm still up in the air with finishing as I'm still in my college apartment with no room to work. Once I take them back to my parents I'll talk with my dad who has a lot of woodworking/finishing experience. I want to go with a light color similar to the ones below or a dark black that will still show some wood grain. The darker black will match the current speakers/subwoofer but I plan on replacing those sometime soon.

Thanks again for all the help and I'll try to finish these up within the month.


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