Beginner help with portable multiway speaker project

[hey_homes]

Hey guys, I posted a thread here a while ago to get some suggestions for my first speaker build and I got loads. However, due to non-audio related distractions and general lack of motivation and money I haven't done anything about it. But now, as summer approaches I've developed a renewed viguor for building some speakers except I have now modified my goals from a pair of speakers for my home to a single portable loudspeaker that i can power with SLA batteries and a car amp and take to the beach (my ideas for a portable "boombox" is actually why I started browsing these forums).

I have browsed around speakerplans.com a fair bit but their forums are slower moving than these. However they do have a few threads about portable 12V systems which are rather inspiring. There are some in here:

-=SHOW OFF YOUR 12V SYSTEM!!!!=- - Speakerplans.com Forums - Page 1

I want to try my hand at building a single speaker that I can cart around this summer, powered by a car amp and several SLA batteries, but i don't really know where to start - although I do know what I would like to end up with:

- A rugged, reasonably loud speaker with reasonable bass (doesn't have to be massive bass) that is relatively portable (not too concerned if it's a bit heavy though)

As this would be my first build I would like it to be as simple as possible. Could I get away with it being 2-way? I would like to use a ready made crossover as i have no idea about how to go about building one. And driver suggestions would be handy. I would like to keep the bass woofer at 10" or smaller if possible.

It would be great to be able to follow an existing design but I am prepared to take a stab at designing and building the box from scratch.

Thanks in advance for any guidance I receive!

[Moondog55]

Try searching for the "Boominator"

[hey_homes]

Holy crap, this thing is incredible:

The Boominator - another stab at the ultimate party machine

Something a bit less ambitious perhaps.

[Buckapound]

Well, you can attack the project in several steps, and then it can seem a lot more manageable. Figure out how you're going to use it, which will determine size, weight and power. Then look at existing speaker designs that suit your need and figure out how to take their designs and reshape them into something more portable. Build a rough version out of scrap wood or even a couple of layers of foam-core, so the initial fiddling is quick and low-risk.

Then you can put the amp section together (look at Tripath 2020 designs), and power management, with batteries, AC, charger, solar, whatever. I've been working on (and enjoying) mine for a couple of years now. Seems like there's always some improvement to tinker with. I recently switched over from lead-acid batteries to Lithium iron phosphate, which i like much better.

It's a fun and rewarding project that will take a lot of work, but not necessarily a huge amount of technical knowledge, especially if modifying proven speaker designs. Your friends will be amazed. Let us know what you come up with.

--Buckapound

[hey_homes]

Thanks for that, Buckapound. Where would you suggest i search for some existing speaker designs? I assume many can be found on this forum but I don't know any designs/names to look for. If some folks could point me in the right direction that'd be ace.

[TerryO]

You might want to do a "fullrange" speaker. Use a pioneer 8 inch fullrange driver which cost about $25 or so dollars. Put it in a suitable vented box and you'll have a a pretty good speaker for what you want. Judging from your question, I'm assuming that you're young, so your high frequency hearing is probably still good. In that case, you may want to include a super tweeter to add a bit of air. Doesn't have to be very special and you can roll it in pretty high with a single capacitor. Add about another $10 to the cost for that option.

Best regards,
TerryO

[hey_homes]

Not young, Terry, (I'm 27) just not really an electronically minded guy. However, I'll still have a good go at building this thing.

Sorry for my noobism but is a vented box the same as a ported box? I have fiddled around with WinISD so I think I've got a basic grasp on how to model an enclosure but I'm still a bit stuck on how exactly to build a basic enclosure that will also accomodate mid and high drivers.

[TerryO]

Originally Posted by hey_homes

Not young, Terry, (I'm 27) just not really an electronically minded guy. However, I'll still have a good go at building this thing.

Sorry for my noobism but is a vented box the same as a ported box? I have fiddled around with WinISD so I think I've got a basic grasp on how to model an enclosure but I'm still a bit stuck on how exactly to build a basic enclosure that will also accomodate mid and high drivers.

You're not young at 27? I've got children older than that!

Anyway, the answer to your question is yes, a ported and a vented enclosure are terms used for the same thing.

I went and looked up a project that was done a few years back and may be just what you want. It's actually a sealed box, but for outdoor use that may be a bit better anyway.

Here's the URL: Single Driver Website

Best Regards,
TerryO

[hey_homes]

Haha I thought by young you meant 14 or something. Either way, I'm pleased to be considered young!

[TerryO]

Originally Posted by hey_homes

Haha I thought by young you meant 14 or something. Either way, I'm pleased to be considered young!

I'm sure you've heard it before, but time flys. My oldest is 38 and the youngest is 14. I sometimes forget and assume I'm 25, then I wake up and the awful truth washes over me like a wave of despair.


Best Regards,
TerryO