DIY "White Van" Speakers.

[chad1376]

Before you throw fruit at me and boo, let me explain.

For his 9th birthday, my kid wants to help me build him some speakers for his bedroom. I want to build something for around $100, including drivers, crossover, wood and misc hardware.

I know a simple two way with a 6.5" woofer would serve him well, but he's not going to be happy unless he has a three-way with big woofers in a big box.

Also, this needs to be something we can easily build in a weekend - or a day. Basicly, I've used the sort low-to-high function and I've tried to match efficencies of the drivers, so hopefully we'll be able to make something reasonably balanced on the first try.

Tweet:
http://www.parts-express.com/pe/show...number=270-150

Mid:
http://www.parts-express.com/pe/show...number=292-432

Woof:
http://www.parts-express.com/pe/show...number=292-410

Crossover:
http://www.parts-express.com/pe/show...number=260-210

Anyone see anything that can go horribly wrong here - other than lopping off fingers on the table saw?

[XtremeRevolution]

For a very small price increase, I would also consider this tweeter. It has a very smooth response and sounds quite excellent.

http://www.parts-express.com/pe/show...umber=264-1028

[its_bacon12]

That's quite an order for $100... I really can't think of anything that matches your design plans for that budget.

[tom_s]

For a very small price increase, I would also consider this tweeter. It has a very smooth response and sounds quite excellent.

http://www.parts-express.com/pe/show...umber=264-1028

You beat me to it!! That is a great tweeter for the money.

Not sure about that mid....no curves posted and they don't even list Xmax. Sealed back would make the build much easier, but you might have better luck with one of the Jamo 5.5" buy outs and create a small sealed space for the mid & tweeter. it's just 2 more pieces of wood. Plus, you can use a little less sensitivity on the mid to help overcome Baffle Step losses. The kid will like em even more if they have a little thump!

[ameuba10]

I think you have chosen some decent drivers for the cost. Most here would whine about the xover, but to be honest, that xover is probably better than those white van speakers anyway. Not to mention this is for a 9yo, and not an audiophile. Looks like a fun build!

[michiganpat]

I'd look at these two projects by Johnnyrichards:

http://techtalk.parts-express.com/sh...d.php?t=226848

http://techtalk.parts-express.com/sh...d.php?t=224467

measured, documented, and reasonable (except for the price increase on the dayton tweet)

[DanP]

I think your kid is going to love these no matter what you do (as long as they've got big woofers like you said), but what bugs me about what you suggest is that the crossovers are expensive and they're not going to sound good. I wouldn't have high hopes for the sound quality on those midranges either.

What if you scrapped the midrange altogether, doubled up on the woofers, upgraded to the suggested Vifa tweeters, and just did a TMM. Then you could just do a simple 2-way design that would have a decent tweeter and tons of output with a semi-customized crossover depending on what resources you have. The woofers are much cheaper when you order 4 and the only downside is going to be off axis response, which I don't think is a big deal given the application.

Dan

[chad1376]

Hmm - I like the TMM idea. There's a lot of inexpensive 8" options.

I want to be carefull about "scope creep" though. If I get into 4-weeks of cabinet construction and crazy crossover modeling, he'll loose interest and this won't be a father/son thing anymore.

More than likely, this setup will utilize his i-pod and a little T-amp. The big speakers are really for visual impact and so he can show off his system to his 9-year old freinds. I almost think a two-way with a big passive radiator would work well. Honestly, he won't know the passive radiator isn't really a powered speaker. Unfortunately, the passive radiators are more expensive than some of the woofers I'm considering.

[tom_s]

I didn't realize that Johnny had used those mids. His design based on the 12" GRS may cost a little bit more that what you proposed, but not by that much. The big inductor in his is only $10.50. I would bet it will sound much better than any stock crossover, especially due to a few dB of BSC being factored in Johnny's design. Also remember that the stock crossover won't have any padding on the mids or tweeters, so you'll have to juggle those values as you voice.

[patrickm]

to save some extra money on it, you could probably use electrolytic caps instead of poly's, and i don't think it'd be too hard to get that vifa to hit a 4k crossover point.... that would save you about $20 over the dayton ND20FA's. it wouldn't be a direct swap, though, and probably would need more padding too.

also, you can build it, finish it, and go back inside and tweak the crossover later and explain that as speaker break-in ...

[johnnyrichards]

I have one of the Vifa BC15SC buyouts at home,maybe I can work up a new crossover for LSS using that tweeter instead of the Dayton.

Your kid would love the big monkey coffins

[greywarden]

Yeah me and my dad are going to build the LSS's when I get home... gotta order the parts, come to think of it.

[DanP]

If you could copy a crossover for that Vifa tweet that was cheap and had a smooth rolloff, you could order a few cheap resistors to get the padding right and guess on a lowpass for the woofers (TMM). If you got a coil and a couple caps for the lowpass, you could have several combos to try:

1) woofers run full range - no low pass
2) coil in series with woofer - 6dB electrical
3) coil in series + 1 cap shunt
4) coil in series + other cap shunt
5) coil in series + caps in series shunt
6) coil in series + caps in parallel shunt

This is quite a few options and I bet one of them would sound better than that stock 3-way.

Dan

[arlis_1957@yahoo.com]

You beat me to it!! That is a great tweeter for the money.

Not sure about that mid....no curves posted and they don't even list Xmax. Sealed back would make the build much easier, but you might have better luck with one of the Jamo 5.5" buy outs and create a small sealed space for the mid & tweeter. it's just 2 more pieces of wood. Plus, you can use a little less sensitivity on the mid to help overcome Baffle Step losses. The kid will like em even more if they have a little thump!

http://techtalk.parts-express.com/sh...d.php?t=223658
some info on the mid.