Building bookshelf speakers

[martix_agent]

this is my first post ever here and i think it's going to be a doosie! I chose this site because it's smaller yet seems to have some solid members. Please bear with me as I attempt to explain what I'm trying to accomplish.

Over the winter I built a sub box for the heck of it and was surprised how much fun it was. It's a 12 inch driver powered by a 200w amplifier with high pass filters for the speakers and a variable range from..well i'm not sure, I'm not feeling up to pulling it away from the wall. Finally, it's tuned somewhere around 27 hertz. I had to fudge a few things when i got it all cut out because my port would have run into the driver if I had used the orgional plans...which is weird because I though I had it all calculated correctly.

There's my background, now onto the juicy stuff.

I still have half of the MFD board that I bought to build that speaker and now I'm hunting for good bookshelf speakers. Since I've got some extra left over I figured why not build my own bookshelf speakers? I have about a zillion questions before i even start believing I can possibly do it though.

I'm looking for these to be my main speakers, currently all i have is the sub i built that i've been using on my computer. my computer speakers died and I pick up a reciever/amplifier with full surround features so I figured it's a good time to start working on getting a surround system running. it's a 240W pioneer for I'd say 5ish years ago maybe. My parents got a new reciever with better things and gave me this one.

Since I have a sub already, What do I need in these speakers?
I'm also wondering if there's a noticeable difference between 3-way and 2-way?
I understand what crossovers do and why they are needed, but how do i know what I need in a crossover?
Do you know of any places where I can get some basic box dimensions? that was the hardest for me when i built my sub box, finding information that was reliable. seems every place says something different.
Do i need to use the same speakers for both main speakers and the center speaker?(whihc i'm also considering building, if what i get is cheap enough and i have enough MFD leftover.) What about the rear speakers? I'm unsure what this will be used for more, movies or music. I'm not sure if that makes a difference or not.

Lastly my budget is around $120ish, i may be able to go a bit higher though, if I feel it's worth it.

I really like buying from parts express, as they have an incredible selection and ship to me very quickly as they're only a few hours away. I believe that's the sit I'll be using to get my things unless I can be convinced otherwise.

[kexodusc]

Hi,
I recommend you take a look at the Parts Express Project Showcase and Tech Talk forums.
Building speakers is a bit more complicated than building a subwoofer and you would probably be further ahead to start with a kit or pre-planned project. This way you could learn the ropes, understand the physics behind every step, and better prepare yourself for the next project.

This is how most of us get started with building speakers.
http://www.pesupport.com/cgi-bin/config.pl
http://www.partsexpress.com/projectshowcase/index.cfm

The folks there are very knowledgeable and friendly, and focused specifically on speaker building.

$120 is a good budget for your first project, you'll do ok, I'm sure.

[martix_agent]

thanks for the links, but I've looked at that section before and it's all way over my head.; not to mention it's a funny setup that I can't figure out; is it a forum, a message board, a randomly placed message center? Nothing makes sine to me, I click on a "post" and get even more links! Not exactly a friendly area to read things in.

i also tried looking at the DIY bookshelf speakers, but all the bookshelf ones use parts that are discontinued now

[GMichael]

thanks for the links, but I've looked at that section before and it's all way over my head.; not to mention it's a funny setup that I can't figure out; is it a forum, a message board, a randomly placed message center? Nothing makes sine to me, I click on a "post" and get even more links! Not exactly a friendly area to read things in.

i also tried looking at the DIY bookshelf speakers, but all the bookshelf ones use parts that are discontinued now

Have you looked at a few of these kits?
http://www.partsexpress.com/webpage....ctGroup_ID=769

[martix_agent]

not a bad find. but the ones in my pricerange have people saying they lack good highs and aren't all that great for main speakers.
besides, for $150 I can go to elemental designs and buy their prebuilt bookshelf speakers. I've learned that anything they make, while pricey, it worth its weight in gold.

[kexodusc]

not a bad find. but the ones in my pricerange have people saying they lack good highs and aren't all that great for main speakers.
besides, for $150 I can go to elemental designs and buy their prebuilt bookshelf speakers. I've learned that anything they make, while pricey, it worth its weight in gold.

Which model are you referring to? Most people would be thrilled to have any of those speaker kits as their main speakers, and for the price they sell at, you couldn't buy better speakers in a store. I've built a few of those kits for people. The BR-1's are a great value - the aluminum MTM's are probably my personal favorite. Go with the dual 7" woofers though...

If you can make your own cabinets, those aluminum woofers are very hard to beat. Especially coupled in an MTM alignment. Here's another project that is highly regarded, and might fall within your budget. Worth saving up the money. Designed by a reputable member of the DIY community. Zaph's web page should be a bookmark for all.
http://zaphaudio.com/BAMTM.html

[martix_agent]

I was refering to these
http://www.partsexpress.com/pe/showd...number=300-640

that speaker build you got there looks interesting.

[GMichael]

not a bad find. but the ones in my pricerange have people saying they lack good highs and aren't all that great for main speakers.
besides, for $150 I can go to elemental designs and buy their prebuilt bookshelf speakers. I've learned that anything they make, while pricey, it worth its weight in gold.

You could get a little daring and try to put something together on your own. The components below would go together nicely and have a little more output than the BR-1 kits. You could also sub out the shielded drives with unshielded to save a little cash. But then you can't have them too close to a TV. Stay away from ported designs until you have a little more experience.
Add a little MDF and some insulation and you'll be ready to play. These would sound better than most speakers costing 2x as much.

260-140 Yes Dayton XO2W-2K 2-Way Crossover 2,000 Hz .. $27.67 each $55.34 total

275-075 Yes Dayton DC28FS-8 1-1/8" Shielded Silk Do .. $16.75 each $33.50

295-364 Yes Dayton RS180S-8 7" Reference Shielded W .. $34.96 each $69.92

Subtotal: $158.76

[martix_agent]

yeah now we're cooking with gas. the entire intent on me building my own was to get something better than what i could buy pre-assembeled for cheaper.
I've still not gotten an answer about if a 3 way is better or not.

question michael, how do you know which crossover is best? and i see the drivers you selected are a 90w max. Do you foresee that as a potential problem when using a 240w reciever/amplifier?


question kex, in that article he talks about those amazing tweeters, but the link to them is dead. are they still made? and why do you say go with 7 inch woofers? wouldn't that also change the box size?

what about this? it's half price
http://www.partsexpress.com/pe/showd...number=299-164

[kexodusc]

The links are probably still made you'll just have to search the model number.

Martix_agent, I strongly recommend going with a design someone has already built. You can't just take an off-the shelf crossover, and a woofer and tweeter, and put them together. Those crossovers aren't optimized to the impedance profile and usuable ranges of the drivers. You are likely to end up with a poor sounding speaker that has a lot of potential but isn't getting the job done.

The BR-1 kit you were looking at is an AWESOME little kit for the money. I have personally built and compared them against my Axiom M3Ti bookshelf speakers and aside from the low efficiency, they were a better performer. They're not much to look at but the bass is solid and accurate, the midrange is clean and the highs are smooth. And they image very well. They would be a great 1st project and many of the guys on the Parts Express forum started with it. You won't be disappointed!

[martix_agent]

I know i should listen to you guys, my brain is telling me to. But a little voice in my head wants to push onward. I realize I can't just throw random speakers together but can somebody explain to me why that is? Or maybe a better question would be how I know what matches with what? I can't seem to find any stickies about things like that around this forum.

I wish I could hear that kit before i bought it...and also, I can get these for the same price, without having to assemble them(whihc is sorta defeating the whole purpose of this...)

[Feanor]

martix_agent, there are many good books on the subject of DIY speaker design and building. Here are a couple of examples:

• http://www.partsexpress.com/pe/showd...number=500-021
• http://www.partsexpress.com/pe/showd...number=500-035

One of these days, (hopefully soon ratther than later), I'm going to buld a pair of these Accuton-based speakers. I worked up this design using the Harris Tech X-Over Pro and BassBox Pro programs ...




These ain't no $120, though. Cost of parts roughly $2000.

[kexodusc]

I don't know anything about the elemental designs model. Maybe it's pretty good. I do know the BR-1's been out for maybe 5 years now and has withstood the test of time.

About 4 years ago I got a real itch to build my own speakers too. I was fortunate to have an experienced neighbor who'd been doing it for years.

My first solo project was an inexpensive kit from Madisound. The EFE DIY project actually. I had enthusiasm to build speakers, a workshop full of tools, some wood working skills, but I was a few years removed from physics class. I bought a lot of books and read a lot of good web pages.

You really have to take small steps here.

I know i should listen to you guys, my brain is telling me to. But a little voice in my head wants to push onward. I realize I can't just throw random speakers together but can somebody explain to me why that is?

Variety of reasons - technically, you could throw any 2 drivers together. To make them cooperate, you need a good crossover network. Crossover design is NOT simple. You can't just plug numbers into a calculator, solder a few caps and inductors onto a board and call it a day. Well you could, but it wouldn't sound great. Each driver has a unique fingerprint, behaves differently across its usuful range of frequencies. They behave differently in electrical terms. The behavior of one affects the performance of another in a system. Each step has to be well considered and executed or the result will be compromised. I've know a few people who just connected drivers together in a box with a simple 2nd order crossover off the shelf and couldn't figure out why $300 in parts sounded like crap, while the speaker I made for $100 sounded so good. Ya just gotta trust the Kex man on this.

Or maybe a better question would be how I know what matches with what? I can't seem to find any stickies about things like that around this forum.

That's cause this forum isn't that good for DIY stuff. The Parts Express site is. It's worth the time it'll take you to figure out the format. Introduce yourself there, ask some questions or for a recommendation on a good first project. They'll help you out there, and you can be assured they won't steer you off course. Their goal is to make your project so enjoyable for you that you join the DIY hobbyist community - because it's sort of in their best interest to have as many newbies supporting the industry as possible.

If you want an easy project to put together for the purpose of buying and building a good sounding speaker, go with a kit. Fast, and guaranteed performance. If you want to do this because it's fun, take the time to learn, ask questions. After awhile you'll be building your own designs.

I'm not trying to discourage you - this stuff isn't that hard and there's lots of people willing to help answer questions. I just don't want you to throw a bunch of money at a first project, have a bad experience with it, and give up. If your first project has better results, you're more likely to start a 2nd project, and a 3rd, etc...or at least think favorably of the experience. Keep it simple for now.

[martix_agent]

I understand exactly what your'e saying. I suppose I'll hit up the parts express forums to gain more knowlege. I know this project can be devstating if i dont' do it right and yet I want to proceed in doing it because I know it's something I'll enjoy.

The funny thing is that I'm an avid paintballer and moderator of a paintball forum. We get new players in and I'll tell them to start on something cheap and not so good first so they can make their mistakes using them first before moving on to the better things. Maybe I should take that philosophy into this project and listen to you guys. If anything, I'll have some decent rear speakers and I can build the nice ones later when I know more I'm still debating if i shoudl go with gmichaels suggestion, the kit from parts-express or the elemental designs one...descisions, descisions..

[audio amateur]

I know i should listen to you guys, my brain is telling me to. But a little voice in my head wants to push onward. I realize I can't just throw random speakers together but can somebody explain to me why that is? Or maybe a better question would be how I know what matches with what? I can't seem to find any stickies about things like that around this forum.

I wish I could hear that kit before i bought it...and also, I can get these for the same price, without having to assemble them(whihc is sorta defeating the whole purpose of this...)

If anything, Feanor just answered this question with his post. As you can see, speaker building involves a lot, and is much more complicated than you think. Matching the crossover and drivers is crucial, and is not an easy task. Good luck, and follow their advise!

[Mark of Cenla]

I would get a small full-range speaker since you already have a sub. That way there is no crossover. You will be amazed at how open it will sound. This is just one guy's opinion. Good luck.

[martix_agent]

After much though I've nearly decided what I want to build. I'd like some help determining what size box i need though before I decide. I've also heard that using insulation can decrease the box size. Is that true?
setup #1:
http://www.partsexpress.com/pe/pshow...75-075&scqty=3 x3(one for each speaker, one for the center speaker)
http://www.partsexpress.com/pe/pshow...95-360&scqty=1 x2 (one for each speaker)
http://www.partsexpress.com/pe/pshow...75-075&scqty=3 x1(for the center speaker)

setup #2:
http://www.partsexpress.com/pe/pshow...75-075&scqty=3 x3(one for each speaker, one for the center speaker)
http://www.partsexpress.com/pe/pshow...95-362&scqty=3 x3(one for each speaker, one for the center speaker)

setup#3:
http://www.partsexpress.com/pe/pshow...75-075&scqty=3 x3(one for each speaker, one for the center speaker)
http://www.partsexpress.com/pe/pshow...95-360&scqty=1 x5 (two for each speaker, one for the center speaker)

[martix_agent]

not to be inconsiderate, because this was an old thread. but can anyone point me to formulas at least that can help me out?

[audio amateur]

not to be inconsiderate, because this was an old thread. but can anyone point me to formulas at least that can help me out?

Sorry I don't think I can help you on that.