Intro to DIY SpeakersSilly as it may seem, building speakers is a lot of fun, andpossibly addicting. However, it's not an easy hobby to learn becauseit's not as well-documented as other hobbies or professions. Theinternet has really opened things up for the DIY community, andcomputer tools have allowed average enthusiasts to create homespunprojects that sound better than speakers costing several times thatamount at a home theater or HiFi store.
Where to Start?The best way to get started with DIYspeakers is to hear or build aproven design. There are many good ones to choose from currently.Chances are, once you feel the immense satisfaction of buildingsomething that sounds so good with your own two hands, you'll be hooked(You'll probably also feel ashamed for spending so much money onstore-bought speakers). Here are some of the best designs for abeginner:(Wayne Jaeschke) - Bookshelf MTM with bass extension that seems to defyphysics. They image great, and have a fun overall sound-excellent forRock and Acoustic music.
You'll be amazed that $175 worth ofelectronics will sound this good. The best part about this design isthat a very generous person wrote a fairly detailed on how to build them.(Curt Campbell) - MTM design that can be adapted for anything from asmall bookshelf to floorstanding cabinets. Amazingly low parts countmeans they are easy to wire (and debug in case of problems), and willonly cost about $150 in electronics for a pair. They make a great hometheater. Curt also did a of the TriTrix which pack a ridiculous amount of value for the buck!(Jon Marsh) - Bookshelf TM with a well-balanced, highly detailedsound. Good for every taste in music and home theater. It uses somemad science in the crossover-don't even ask me to explain it.However, many, many people have built them, so don't be intimidated.These will cost around $250 in electronics.(Lou Coraggio) - These are relatively small TM bookshelf designs thatpair up the highly-detailed-yet-hard-to-tame Dayton RS woofers withvery good tweeters.
All of Lou's designs show a good blend ofpracticality, musicality, and approachability. You really can't gowrong with any of them.(Roman Bednarek) - A small TM design. Works wonderfully for hometheater or computer speakers. Cheap to build, yet surprisingly highperformance.
I've never heard a bad word said about them!(Wayne Jaeschke) - Large MTM towers. If a bookshelf design just isn'tgoing to cut it for you, and you really want to rattle the rafters,this is the design you've been looking for. They will cost around $200in parts and they will rock like you've never heard. Throw away yoursub.(Jon Marsh) - Large bookshelf MTM.
These will give you a bit morepunch than the Modula MT, but still employ a lot of the same spaghetticrossover design Jon Marsh is famous for. These will cost around $300,but will definitely satisfy most any refined taste. Many people tendto pair these up with a sub.(CJD) - CJD described these to me as 'An RS version of the DaytonIII.' They pump out a surprising amount of bass, but are otherwisevery neutral. The only difficulty a beginner may have with these isthat it requires knowledge of how to translate a crossover diagram intophysical parts.(John 'Zaph' Krutke) - Proves that when you pair up low-distortion, easy-to-work-with drivers, you can get great results without too many crossover parts. Has a neutral sound that should suit most listening tastes., - All designs use drivers that are pretty good for the money, paired up with a crossover meant to get the most performance from the drivers. Plus, they all come in at $100 or less for the drivers and crossover component parts!Note: Just because these are 'beginner'projects does not mean you will sacrifice anything in terms of soundquality.
In fact, should you continue with the hobby and design yourown, it will probably be a long time before you build something thatrivals any of these designs! Next StepOkay,so now you have all the weird quirks of building a speaker under yourbelt (and yes, there are a bunch). What comes next?. You can build a more complicated proven design, such as a 3-way, or a 2-way using higher quality drivers. Leaf through my section and do some investigation of your own to find designs you might want to try.
You can experiment with designing your own speakers using some of the excellent freeware available such as Jeff Bagby's. You'll also need some sort of box-response modeling program: and are both fantastic and free.
There are commercial software packages for speaker design, but honestly the free stuff I mentioned above is as good-if not better-than many of the retail loudspeaker design programs. Save your money.
Iknow I'm not the first to say it, and I definitely won't be the last,but you really owe it to yourself to purchase and read Ray Alden's Speakerbuilding 201 and Vance Dickason's Loudspeaker Design Cook Book.I can almost guarantee that these books will overwhelm you at first,and the amount of math and engineering involved will be intimidating,not to mention the fact that they are full of graphs and tables usingunits you've probably never heard of. The information will not sink inupon first read. Rather, you have to try out some of the things in thebook to hear them for yourself. Then, as you go back and re-read thebook, things will actually start to make sense.
I promise. Don'tget hung up on theoretical problems.
Just go ahead and try some stuffout. There aren't many things more annoying to me in the DIY worldthan guys who pontificate about all sorts of theoretical projects, andissues related to musical reproduction-but never actually buildanything! For God's sake, go make some sawdust, hook up some drivers,find out what happens. As Andy G would say, 'The best way to learn isto do.'
Passive Crossover Designer
Mastered that?If you have theguts, and are willing to deal with some trial and error, and a bunch oftweaking, it's time to build your own designs, and bring them to DIYevents. Anyway, since you're now answering to no one but yourself,it's time to be creative and original; you can use any drivers andbuild any kind of box (or non-box) you want!The final frontier of DIY speakersUnlessyour design wins a DIY event, it probably won't get much notice unlessyou do some measuring. Measuring can be a total PITA, and requires abit of an investment in a measurement mic ($50+) and a mic preamp($60+), and an SPL meter ($50). You can usually use your computer'sbuilt-in sound card, but it often requires a bit of skill in wielding asoldering iron and making your own cables.Then there's themeasurement software. Of the software I have tried, I have actuallymanaged to get some results using these:.- This will require you either build some custom cables or a testingjig. But everything is thoroughly documented, so don't get scaredyet. The problem is that the software is extremely complex and notvery intuitive.
Passive Crossover Design Software
It also requires a lot of calibration each time, thesteps of which are easy to forget. On the plus side, this softwarepackage can do pretty much everything from soup to nuts, and costsnothing. This is a shareware program, and it will perform a lot of tasks, it just won't let you save unless you pay. In my opinion, the documentation for this program is pretty lousy; however, if you know what you're doing and you have the patience to fiddle with it, it can perform most of the same tasks that the uber-expensive measurement packages can do.- This is a commercial piece of software, however the free demo versionis pretty useful, and can do a lot of handy tasks (you cannot save your files, though). It isdesigned around 'modules' that you can run to perform operations; themodules are very well-documented and easy to understand. You'll stillhave to build some simple custom cables, unless you buy the retailversion, in which case you get all the measurement equipment you need.
Age mythology compressed. Thissoftware is not free at all. It comes bundled with the design programLSPCad.
It's meant to be as simple and straightforward as possible.Once you slug your way through the confusingEnglish-as-a-second-language manual, it really is extremely easy to useand very reliable.' But how do I measure?' Is thequestion on so many intermediate speaker designer's lips. So far, Ihaven't found a decent set of instructions on the internet onhow to measure loudspeakers that wasn't either confusing, or containedtoo much, or not enough information. However, there is an excellent book written by Joe D'Appolito titled Measuring Loudspeakers,which really fills you in on everything you needed to know onmeasurement, and also contains all sorts of interesting asides about speakerdesign.
It does require a decent understanding of loudspeaker design,though-that is, you've read and understood Ray Alden's Speakerbuilding 201 and/or Vance Dickason's Loudspeaker Design Cook Book.