DIY Speaker Project

[TESLA]

For a while now I have wanted a new set of bookshelves for my computer at college.

I have never gotten around to buying a pair, however, because of the lack of funds required to get something to really suit my wants.

With an extended break from commitments approaching, I have decided upon building my own bookshelves as a solution, and this thread will hopefully solve my two problems in completing my task.

First, this thread, combined with others, will hopefully help me not mess up entirely, and provide me with some motivation.

For my initial plans I have decided to go with two 13.5” deep cabinets with 10” by 8.5” faces constructed of .75” and .5” MDF.

The MDF will be cut as follows:

1. 3x 12” by 7” by .75”
2. 2x 13.5” by 10” by .75”
3. 2x 10” by 7” by .75”
4. 2x 12” by 4.25” by .5”
5. 2x 6” by 4.25” by .5”
6. 2x 12” by 3.5” by .5”
7. 2x 6” by 3.5” by .5”

The three cuts under label 1 will be cut in the following ways with a hole-saw set:

Baffle:


Middle Brace:


Back Plate:


The back plate will consist of the binding post plate and a flared 1.5” x 4” long port.

The picture below will hopefully give a decent idea of how the cabinets should come together (top and bottom panels excluded):


Red = Baffle
Light Blue = Middle Brace
Dark Blue = Back Plate
Green = Label 2
Yellow = Label 4
Purple = Label 6

(Do not worry about grey and white.)

Electronics:

For the drivers I have decided to go with Hi-Vi.
(Hi-Vi = Swans Speakers)
I will be using the same drivers found in Swans M1 monitor, the F5 5” mid-woofer and the RT1C-A planar tweeter, mostly because both of them fit my budget and size constraints for this project, and the M1 remains one of my favorite monitors.

Keep in mind that I will be using these bookshelves in a 2.1 configuration; I have just decided not to build my own subwoofer as I figured the Dayton 10” 150watt pre-built subwoofer is as good as any I will be able to make within my budget.

The only thing left in the design stage (aside from changes) is the crossover.

Each speaker will be handling well under 100watts of power.
The tweeter operates at a nominal impedance of 5 ohms and the woofer operates at a nominal impedance of 8 ohms.

I believe I will aim to set the frequency at about 3,500 to 4000 Hz and will implement a second order (12db) Linkwitz-Riley design.

I only need a 2-way crossover so it should not be too complicated, when I find the time.


Thoughts?

 

[dandragonrage]

Nooo. Hi-Vi. Most of their drivers take a lot of crossover work to sound decent.

Where did you get the box design? Did you calculate it?

 

[threedd97]

He sounds like he knows what he is talking about from what I read, so I would hope to assume he has the enclosure calculated out right for the drivers and speakers he will put in it.

 

[TESLA]

Nooo. Hi-Vi. Most of their drivers take a lot of crossover work to sound decent.

Oh well, I am not bad with circuits by any means, and I tinker with everything anyway.

Where did you get the box design? Did you calculate it?

I did, but I think I will move the drivers closer together and make the cabinets deeper now that I think about it more.

As it stands now, it is based on what other speaker builders have told me.

EDIT: Yeah, I will need to build a fourth order filter for the planar tweeter as it looks like it frowns upon overlapping signals and requires more isolation from the woofer driver.

 

[Ahriman4891]

I guess you already saw these?

http://www.swanspeaker.com/speaker/htm/index.asp?type=D

They provide both cabinet and xover schemes.

 

[dandragonrage]

Put the drivers absolutely as close together as you can. The higher your crossover, the closer they need to be. And don't center the tweeter.