My first DIY speaker

[Feanor]

Gotta brag just a bit: my first DIY is complete. Well almost: maybe a bit more padding on the tweater.

See a pic ...
http://gallery.audioasylum.com/cgi/view.mpl?u=20428&f=DIY_center_channel2.jpg&v=f&UserImages=20428&session=&&moniker=Feanor&invite=&w=800&h=533

I wanted to limit my money & time risk so I decided to go for a center channel only; also, I decide on a single woofer instead of the more common dual configuration. Woofer is a Vifa MG18SK09-04 which is shielded; tweeter is Bohlender-Graebener Neo3PDR-FP. The tweeter is quite sweet, open, and transparent.

I used 2nd order crossovers at 2000 Hz and no baffle step compensation because the unit sits on top of my old CRT TV. As I said, the tweaker needs to be padded down a couple of decibals, where for lack of BSC or otherwise I'm not sure. I used Solen caps plus an 1 mF AudioCap Theta by-pass on the tweeter, and Janzen copper foil inductors.

Construction was simple, glued & screwed butt joint. Finish is Parts Express vinyl laminate. I used Sonic Barrier damping pads exclusively.

[bjornb17]

man thats gorgeous.

That makes me want to dive into DIY as im writing this. Actually I am planning a subwoofer.


How much did the whole thing cost you?

[Feanor]

man thats gorgeous.

That makes me want to dive into DIY as im writing this. Actually I am planning a subwoofer.

How much did the whole thing cost you?
I bought the components and bits & pieces over the span of several months and it's a bit hard doing the final reconning. The parts of the speaker itself would go something like this, (all very approximate: US$ since I bought most stuff from Parts Express):

Vifa woofer: $61
B-G tweeter: $44
B-G faceplate: $7
X-over inductors: $25
Capacitors: $20
Sonic Barrier damping sheets: $30
2" vent: $3
2'x4'X75" MDF: $12
Extra sawing of the MDF at Home Depot: $5
Banana jacks: $7
Vinyl laminate: $15
Other screws, hardware, etc.: $15
Cross-border shipping from Parts Express: $50, (multiple orders)

Looks like about US$290 -- not that cheap! This is only ONE speaker, not a pair. But that's not really the whole cost. In addition I had to buy:

HarrisTech Bass Box Pro and X-Over Pro software: $180
Plunge router: $120
Router bits: $30
Jasper circle cutting jig: $27
Of course, these latter things I might use again. And I intend to do so! I'm thinking now of a pair of fronts. I'll use similar components to my center channel; the price should come in a bit less than twice that of the center itself.

[kexodusc]

Looks great, Feanor...You didn't spare any expense on that unit. What main speakers are you using with it? Now you'll have to build at least 2 for timbre matching.
Damn, I bet that sounds nice, the Neo3PDR-FP is really popular.

[bjornb17]

it makes me come to the realizatoin that i should probably wait until i finish college before i take up any DIY projects, i dont think i can afford them now :)

[kexodusc]

it makes me come to the realizatoin that i should probably wait until i finish college before i take up any DIY projects, i dont think i can afford them now :)

I wouldn't say that...Feanor has built himself an unusually expensive center channel using some pretty excellent drivers. No doubt it sounds amazing. I've built 2 really good center channels now for under $150 that sound very good and would cost a lot more commercially to buy.

If you don't have the tools, kits are probably your best option, unless you have friends with tools. For your sub project, you could probably find a cabinet or find someone to build one cheap.

[Feanor]

Looks great, Feanor...You didn't spare any expense on that unit. What main speakers are you using with it? Now you'll have to build at least 2 for timbre matching.
Damn, I bet that sounds nice, the Neo3PDR-FP is really popular.
Right now I'm using Paradigm MiniMonitors. They are not a close timbre match for the Vifa/BG center, (although padding down the latter's tweeter a couple of dB will help).

I'm thinking of building some fronts that will be a closer match. I built a couple of boxes 3-4 years ago but didn't have the guts to buy the components to fill them. But I think I have the courage now! :cool:

I will use the BG Neo3PDR's there for sure. Possible the same Vifa MG18SX09's, maybe PL18WO09's, or maybe even Seas L18RNX/P's; (but Seas Excel are 'way too expensive).

[kexodusc]

Good call on using a tweeter/woofer arrangement for the center channel. The more measurements I read, topologies I study, the more I'm convinced the effort/reward is just not there for your typical midwoofer-tweeter-midwoofer (MTM) config. Too many crossover difficulties, tonality mismatches and lobbing issues. Ideally you'd use the same xo (with BSC if necessary) and drivers for your mains.
bigger boxes is an option now. Normally newbie DIY-ers don't rush out and buy a $60 Vifa woofers and $45 Neo tweets, but, whatever, more incentive to succeed with that kind cash invested. Good for you.

Bigger boxes and slight mod to the XO -should be easy to make matching mains....how does the speaker sound?

[Feanor]

...
Bigger boxes and slight mod to the XO -should be easy to make matching mains....how does the speaker sound?
Actually I'd like to user the boxes that I've already made and they are just a bit smaller. Consequently performance might be very slightly compromised, but that's OK.

I'm no expert but I haven't heard compelling reasons for the horizontal MTM arrangement. Plus I wanted to save a bit of money. What I do wish, though, is that I'd but the woofer in the middle rather than the tweeter. That would have sounded and looked marginally better I suspect.

The speaker sounds pretty good. I think it will benefit by the slight tweeter reduction I mention, but it is already more transparent and, I think, more dynamic than the MiniMonitors.

[kexodusc]

Do you have any info on the crossover you put together?

[Feanor]

Do you have any info on the crossover you put together?
I'll make up the network diagram in Visio and post it in a day or two. The original, X-Over Pro diagram is missing a couple of elements I added.

[jclin4]

Finish is Parts Express vinyl laminate.

I agree; these speakers look great. Looks like you used the Cherry or Red Maple vinyl. Do you mind sharing which you used?

[Feanor]

I agree; these speakers look great. Looks like you used the Cherry or Red Maple vinyl. Do you mind sharing which you used?
I used Parts Express' vinyl laminate in "Cherry". To tell you the truth though, I should probably have used "Textured Black" for a closer match to my other components.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-014

This stuff looks OK from a distance, but it's hardly a deluxe finish -- just that it's better than raw MDF and easier than painting. Next time, (if there's a next time), I might try the Band-It stuff, e.g. ...

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-046

[kexodusc]

Feanor: Nothing wrong with Band-It, but you can get better for cheaper at a few places. I recommend Iron on or Peel-n-Stick veneers for the absolute newbie, but I'll let you decide how much difficulty you're willing to take.

Oh, and are you sure you got Cherry laminate? I ordered some Red Maple recently and that's what it looks like. The PE cherry is really a dark red rosewood color. Might be the camera losing some tint though?

[Feanor]

Here's my crossover design for this speaker ...

http://gallery.audioasylum.com/cgi/upload.mpl?u=20428&f=X-over_centre.jpg&v=f&UserImages=20428&session=&invite=&w=563&h=314
Note that 2 ohm resistor upstream resistor is to keep the total impedance over 3 ohm; the 3 ohm immediately before the tweeter was added belatedly to attenuate the tweeter by about 2 dB.

The .47 uF by-pass capacitor is an AudioCap Theta; all other caps are Solen Fast Caps. Both inductors are copper foil.

[Feanor]

Feanor: Nothing wrong with Band-It, but you can get better for cheaper at a few places. I recommend Iron on or Peel-n-Stick veneers for the absolute newbie, but I'll let you decide how much difficulty you're willing to take.

Oh, and are you sure you got Cherry laminate? I ordered some Red Maple recently and that's what it looks like. The PE cherry is really a dark red rosewood color. Might be the camera losing some tint though?
As I recall I did order 'Cherry', though I can't find by bill. On my monitor the vinyl appears is a little cooler than the true color.

I'm no cabinet maker nor do I have the tools for the job. I doubt that I'll buy a table saw for this work, although it would be cost effective if I were to build 3-4 pairs of speakers. This time I had Home Depot saw the MDF; they did a more precise job than I could have with a circular saw.