Back in the 1980’s there was a movie cliché that the person with the largest boombox on their shoulder was always the coolest. It’s obvious to us that [Tim Gremalm] thinks that’s silly. Why be uncomfortable carrying something like that on your shoulder when you can strap a much larger object to your back? He’s working on a mammoth speaker enclosure which can be carried around, but he needed a set of backpack straps to make it happen.
This thing is going to be adding some serious weight to his body, so he also whipped up the padded waist belt seen above. For fabric he reused an Ikea couch cover. The material is made to survive a lot of pulling and stretching. For padding he used what he calls ‘floor mop’. It looks like it might be microfiber mop cloth be we can’t really be sure. With ten layers of the mop encased in the couch cover he finish off each strap by sewing it to some nylon webbing.
After the break you can see a picture of [Tim] modelling the huge polycarbonate speaker enclosure for which these backpack and waist straps were made. This project has many posts associated with it so if you’re interested in seeing more you can use this project tag link.
maybe you can help me with heat rash… 18AH SLA hurts the back, and the skin XD
PS: and the everything else; neck, shoulders, waist, hips, yep, 12v18ah LEAD battery hurts, litterally
dont drop it on your toe! muahaha
SLA is grandpa’s battery. A lipo pack capable of the same run time (prolly 10ah would do) would only weigh a few pounds.
Neat, but it will not work. that polycarbonate is far too thin for the driver sizes. the cabinet will flex way too much. they need to put in a LOT of internal bracing to stiffen that box.
The ports don’t look like their tuned properly. Just arbitrary holes. Pro tip: they’re not just for looks…the solid mass of air in them couples with the air spring in the box, which gives about a 90 degree phase shift above tuning. Which is good, since it nets you about 3dB above tuning, and below it you’ll roll off quicker (24dB/oct vs 12 in a sealed box). Anywho if they’re just random holes, they’ll be tuned much to high to be useful.
Another pro tip. Go read the article before you comment out your butt.
There aren’t any ports in it. It will have two woofers (the big round drivers), and two horns (the 2 retangular holes). It is going to be a sealed enclosure.
Any other holes in it will only be to run the wiring, but right now (based on his sketches and images) there aren’t any other holes (or ports) in the box.
actually there are FOUR woofer holes and two midrange horns. if you actually looked at the picture closely you would’ve seen that.
Why not convert a hiking backpack?
My thoughts exactly. If this thing has any appreciable weight, straps alone are not going to be comfortable for more than a few minutes. A lot fo research and development have gone into the ergonomics of hiking backpacks. Why reinvent the wheel when you can copy it and say yourself a lot of (back)pain? Also important, the location and distrbution of the weight. Put as much up high as possible to make it eaiser on yourself.
Looks like 1″ or (possibly) 1 1/2″ strap. I have a pile of 2″ webbing that was used formerly as for tie down straps for flat-bed trailers. STRONG stuff, a tiny bit stiffer than typical 1″ or 1 1/2″ strap (not to mention thicker), and should spread the weight a bit more. It is quite a bit like the strapping used in safety harnesses (down to the uniform yellow). I plan to use some of this if I ever get around to making my own backpack (or sex swing, or whatever). I have a couple of 4″ straps, but sourcing buckles for it may prove difficult.
If you know any long haul truckers (or any OTR drivers), see if they know where to get some old straps. Some companies REQUIRE periodic replacement, and I assume some states mandate the same. They are reasonably soft once washed (I washed mine in the washer (and then into the dryer)), and I assume they should dye as well as any other synthetic cloth.
Links are down :(
Helpful stuff, I was wondering how to carry a 22-23″ homemade laptop weighing 20kg and a custom backpack seems like the only way.
can i get a set of plans for the Electric go cart in the background there?
12’s look really big to put on your back, you only really need a sub and then tweeters, your brain will fill in the mid range for you. it will decrease the weight for sure. I like the idea and have made similar in the past. as for the guy talking about tuning, thats only totally necessary in larger cabinets for concerts and the like. the holes look like he traced the size of the speakers to be put in there and then cut em out. which is totally fine. I had a backpack that had 1 8 inch sub, electronics salvaged from a durabrand surround system and two tweeters. the sound was great and lasted a few hours. weight was in the 15 pound range, I used lipo’s for the power source and an old rc trickle charger from my micro r/c heli days.i used an old hiking backpack with built in spine support and waste band. I like it, hope it all works out well for you.
Awesome!
You know though – you can buy pretty nice back pack straps for pretty cheap. I made a duluth pack a while back that uses surplus ALICE pack straps that were <$10 a pair.
Might also want to consider a tumpline. Voyageurs moved about a bazillion dead furry animals out of the americas and people everywhere (not the US) use them everyday to carry tons of weight.
Also using a tumpline doesn't preclude shoulder and/or waist straps, You could just use it to spread the weight over more contact points.
Love it though.