River float speakers needs consultation

[torclausen]

Hello,

I have had such good luck on this site with advise. I am hoping I can get some input yet again.

Here in Portland OR, river floating is all the rage in the very short summer. We have epic rivers just out of town. Groups of us float for hours, you know the scene. The river isn't rough, but there are periodic splashes. I've been scheming up a great floating sound system. I'm all ears for a good way to do this, but I do admit, I'm starting to like my plan.

Oh, by the way, there is huge points awarded for thrift, both because there is no money and that it needs to match the low quality beer that is consumed. (there is money if needed) Louder the better. Bass -ier the better.

Here is my plan:

A 5 gallon bucket with a bandpass subwoofer. stuck down into the inside of an inner tube. On the bucket's lid is a small round table top with some inexpensive waterproof speakers mounted on there.

I've found this amazing class d 5.1 amp from hong kong. three 2020 chips running an 12vdc. They even found some way to boost the subwoofer's channel. The amp and a SLA battery would sit in the bucket.

I was dreaming of the bandpass tube coming up and out of the tabletop with a snorkle bend in it.

My questions...

1) can someone help find a proper woofer (SVC) and help design the Bandpass?

2) can the port extend past the enclosure's wall?

3) can the port bend (upside down "J")

4) Got any advise on some 4 ohm waterproof speakers already in enclosures?

I promise to send pictures if I get this going.

If you've gotten this far, thanks for reading this, any, all advise welcome!

T

 

[weltersys]

A 5 gallon bucket with a bandpass subwoofer. stuck down into the inside of an inner tube. On the bucket's lid is a small round table top with some inexpensive waterproof speakers mounted on there.

I was dreaming of the bandpass tube coming up and out of the tabletop with a snorkle bend in it.

My questions...

1) can someone help find a proper woofer (SVC) and help design the Bandpass?
2) can the port extend past the enclosure's wall?
3) can the port bend (upside down "J")
4) Got any advise on some 4 ohm waterproof speakers already in enclosures?

1) A bandpass enclosure normally has the speaker on a baffle inside the cabinet, not exposed to the outside world except through the port.
Bandpass cabinets are more picky about tuning than normal bass reflex alignments, and cheap speakers often have quite a bit of deviation from published parameters, making BP cabinets more of a crap shoot than BR.
2,3) The port can extend past the enclosure wall, use of PVC pipe and standard plumbing elbows work well for what you want to do, a "snorkle" will definitely reduce water ingress.
4) Use of Scotchgaurd or similar waterproof spray can make any speaker waterproof. I heard of a new spray last night containing Mylar that lasts longer than Scotchgaurd (which leaches off after a season or less), but have not found the brand name.

Check Parts Express buyouts for deals on cheap speakers. I have used some 10" costing only $5.00 and 6.5" for $10.00 that work great for low power, unfortunately both of the particular ones I used have sold out.

Using Hornresp (free) you can design a tuning around the speaker and enclosure you decide to use. Coolers make great aquatic cabinets, stiffer than a bucket, though for low power a bucket in water is stiff enough for low power.

 

[torclausen]

That all sounds great. Thanks weltersys.

Then maybe I should skip the bandpass, and just stick a woofer in the top of the bucket and scotch guard it. The thing I didn't like was the water splashing onto the woofer... not because it would harm it, but it would sound weird. Maybe a bass kick would shoot the water off?

Has anyone hear of a enclosure calculator for the mac? free or cheap?

 

[Brian Steele]

That all sounds great. Thanks weltersys.

Then maybe I should skip the bandpass, and just stick a woofer in the top of the bucket and scotch guard it. The thing I didn't like was the water splashing onto the woofer... not because it would harm it, but it would sound weird. Maybe a bass kick would shoot the water off?

Has anyone hear of a enclosure calculator for the mac? free or cheap?

I would suggest going with the sealed design and scotch-guard it. It should be fine, and water would not stay on it for long, I think. Exposure to direct sunlight may be a bigger factor.

There are a few web-based enclosure calculators which should work fine with a Mac. Google's your friend here.

 

[weltersys]

That all sounds great. Thanks weltersys.

Then maybe I should skip the bandpass, and just stick a woofer in the top of the bucket and scotch guard it. The thing I didn't like was the water splashing onto the woofer... not because it would harm it, but it would sound weird. Maybe a bass kick would shoot the water off?

Has anyone hear of a enclosure calculator for the mac? free or cheap?

You can mount the speaker vertically so water does not pool. It is better to mount speakers vertically, many loose suspension (good for LF output) will sag over time if mounted horizontally.
Going with a BR will give you about 6 dB more output in the low end over a sealed box.
For the same volume level, you will only need 1/4 the power, so you can use a much smaller battery to play the same length of time.

With a "P Trap" snorkel bend in the port exiting the top of the cabinet, no water will get inside.

I use Hornresp on my girlfriend's kid's abandoned computer, it was cheaper than getting a copy of Bootcamp and Windows to make it work on my Mac.

That said, for what you are doing you can just copy any appropriate BR design that is close to your bucket size, there are tons of them floating around in just the first 15 pages on this forum.

Art