Home built speakers

Eboy87

Well-Known Member
Has anyone done this before? I have a friend who knows electronics who can help if need be. Basically, what I want to do is build two cabinets with a 15" driver and possibly a horn, or something to that effect. I was thinking about using JBL drivers and building the cabinet out of particle board. Does this sound like a good idea or do I need a reality check.

Also, I'd like to put Speakon inputs on them, but have no idea where to begin my search for any.

This idea really hit me last night, so, needless to say, I havn't compleatly thought it through yet.
 
Yes - The 15" boxes and the 12 and horn boxes that I currently use I built. In the past I have built foldback wedges and musical instrument cabs as well.

The actual process of designing the box is much more difficult than actually constructing it. Speakers boxes are much more than just a just a speaker in a box and you need to design the box around the speaker. You need to decide if the box is to be closed or ported, trapezoidal or cube, cross-over or not (then there are the variations on the cross-over) the need for internal bracing etc.

Most of the information that you need is listed on the specs sheet that comes with the speaker (or on the box). Some manufacturers actually offer “free” box designs for their speakers as well, which takes out a lot of the leg work.

The good news is that now there are lots of software applications that you can use to not only design your box, but also plot the performance before you even pick up a tool. I have played with a lot but WinSpeakrz seems to be one of the best.

There is a demo version that seems to have most features working. There are also a host of web sites that run through how to build a speaker box.

The other consideration is the hardware (corners, grill, handles etc) and for the speakon connectors, I would mount them onto recessed panel (Penn Fabrication will carry all the hardware but others may know better). Again, you will need to find the speakon plugs from others as I am in Australia. And whilst I recommend our country as a tourist destination, it is a bugger of a trip just to pick up some speakon connectors!

I would go with plywood over particleboard as it is stronger. The other question you need to ask is how are you going to finish the box? Carpet, vinyl, paint? More things to consider.

The electronics side is very simple and you might need a friend that is a chippie more. Once you have your box sizes worked out, you may be able to get a local business to run the ply through their table saw for you. Nice clean straight cuts will certainly make life easier for you.

Hope this helped and please ask if you need more info.
 
THanks for the reply. I do have a friend who makes his own circuit boards for model railroads, so I'm pretty sure I can get his help on the electronics end. Also, do you know where I can find this demo Winspeakerz? I also searched through my "techie shelf" and found a buisness card from a local sound company (I worked with one of their enginieers on a show), I might be able ot get the parts I need through them.

As far as crossovers, I plan on running a full range input for the time being, but would like to convert it to high and low inputs for my driverack. How would I do this? I don't know too much about crossovres, so I don't know what I need, or even if i'd have to make it myself.

Thanks in advance for the help
 
WinSpeakerz is definetly a good choice. Electronis isn't much of a challenge for speakers, other than assembling the crossover (if you plan to make them passive).
You should review the Thielle-Small parameters which is what will define the various values of a cabinet.
 
Oh, you can make a switchable Passive/Active crossover, or have 2 inputs (one routed to the internal crossover, one to the components directly).
WinSpeakers provides you with crossover design values according to the Thielle-Small parameters of te speakers you have. There's a number of misconceptions about speakers but if you provide me with the model numbers I'll try and dig up some info about them for you on some free time.
Also, particle board is not a great idea for speakers. Most are done out of birch (best is 13 ply), and you can try MDF, although that tends to warp with water.
 
While I can only hope you get the proper measurements and design for your box, I can help with the materials needed.
I'd suggest MDF if you are making some speakers for light duty use, or around the house. For something a tad more roadworthy I suggest using 13 ply Birch plywood. Most of the higher end speaker boxes are made of 13 ply birch. While a lot of companies have been going with MDF over the last few years, I still say birch ply is much stronger and has better acoustical value.

Your connectors, corners, handles, and recessed plates can all be purchased from Penn Fabrication, or a local dealer of their product. Most of these things can also be found on eBay if they cannot be obtained locally.

Use decent hardware, as this is the backbone of your box.

For a finish, there are many choices. The easiest, and one of the more durable is a carpet finish. This will have to be applied during the construction of the box, and there are many online tutorials for how to do so.
The only other finish I've used for cabinets is black truck bed liner. It's about the best finish I've used, but it can be a bit tricky to apply.

Good luck.
 
Although I think that everyone should attempt to build a pair of speakers or two, it is almost cheaper to just buy a pair these days. By the time that you factor in the cost of the plywood (birch...not MDF!), all of the hardware, and then factor in your time, it really isn't any more cost effective than buying a cheap pair. You can find pre-built cab's on several websites (www.steelsound.com for one - their service sucks but their prices are great) and just pop in the drivers that you are looking for.

On the other hand, if you build a pair and experiment to get them sounding just right, you have given yourself a great education. You will understand how everything works and, even better, how to fix it when it doesn't work.

One thought - plan on having to do some tweaking and don't give up. It is almost impossible to have them sounding perfect the first try, so keep plugging and you will get it.
 
I can see your point but there is more to speaker building that simply getting a pre made cab and dropping a driver into it. Each speaker has its own characteristics and this will affect the performance of it when placed in a box that it is not suited to. Also the choice of closed, vented or bypass boxes will also make a difference.

If you do decide to buy pre made or second hand boxes, I would advise that you work out the volume and the type of box first (probably what stantonsound was thinking but may not have made clear).

Some of the important variables to know are:

nominal impedance
power rating
frequency range
sensitivity and at what measurements
Q factors (mechanical/electrical/total)
VAS (equivalent volume)
cone area
x factors
voice coil impedance and inductance
cone surface are
magnet weight
physical dimensions

When plotting these variable using a speaker box design software program (or calculator if you know how) you can figure out what the response will be in boxes of different size and type.


Note to Tom - any chance of shrinking your avatar to 80 pix wide?
 
http://www.partsexpress.com is a great place for speaker building parts, all your connectors, drivers (raw speakers) and literature on speaker building. They have a significant section of their catalog (and website) dedicated to speaker building. Although most of it is not PA-type speaker building, they do have PA type stuff. Of course, all of the software, and literture is applicableto PA work.

http://www.tchweb.com is where to get all your hardware for speakers & road case repair (or construction!) Parts Express has hardware as well, but the quality of the TCH hardware is much better.

I've build my share of speakers in the past. Be prepared for the possibility of having to do it more than once to get the desired sound, although modern speaker designer software certainly helps tremendously. (i haven't made any recently, and software available when i built mine was poor at best) You won't really save much (if any) money, or get better-sounding speakers this way, but by designing your own, you can get cabinets that are custom-fit to your location, application, and sonic requirements.
 
Hey, thanks guys. I'm gonna start this project soon.

Inaki, do mean dimensions of the cabinate I'm modeling these after? I'm basing my design on JBL's SF12M. I plan on making these as monitor wedges
 
I was planning on just using flat black paint. OK, I'ml ost with this winspeakerz thing. I need help. Basically what I want to build is a two-way cabinate to be used as monitors. I'm gonna put a 15" driver and a HF Horn in it, i'm still looking for those parts, don't know what I'm gonna get yet. I'm modeling it after the JBL SF12M, and the box will have vents in it. I'm making the box itself out of 3/4" birch plywood. Other than this, what other information will I need?
 
That depends on your drivers.
 
Eboy87 said:
I was planning on just using flat black paint. OK, I'ml ost with this winspeakerz thing. I need help. Basically what I want to build is a two-way cabinate to be used as monitors. I'm gonna put a 15" driver and a HF Horn in it, i'm still looking for those parts, don't know what I'm gonna get yet. I'm modeling it after the JBL SF12M, and the box will have vents in it. I'm making the box itself out of 3/4" birch plywood. Other than this, what other information will I need?

Well (as stated above) you need to know what drivers you are going to use. From this, you will get the Thiele-Small parameters that you need to calculate the frequency responses etc.

Winspeakerz will then allow you to plot the performance of the speaker in the box that you have in mind and will also allow you to design your x-over as well.

I would suggest doing a Google search on the topic and reading as few different sources or getting a book (such as the The Loudspeaker Design Cookbook, 5th ed., by Vance Dickason, Audio Amateur Press, Peterborough, 1995).
 
I bet that Swtchcraft are rubbing their hands together.

They get to produce a product that has already been proven and had all the R&D costs picked up my Neutrik (just think how much Neutrik would have spent on designing, testing and marketing). Not to mention that they have the opportunity to make any improvements they see fit.
 
off of the parts express website, I'm getting these for drivers, here's the describtion and part number

Pyle Pro PYM1555 15" driver 292-236
Eminence APT-150 Super Tweeter 290-534
 

Users who are viewing this thread

Back