I've been lurking a few years and learned a lot reading this forum but now I have an idea I wanted some suggestions on. Portable bass amp in a suitcase!
I'm thinking I can pick up a smallish funky old suitcase at the thrift store, put two high spl 4 ohm speakers in it, run it off 8 rechargeable AA's in a holder mounted inside and glue foam inside. The suitcase itself should vibrate some and give it some extra thump. I can even make it lean back or cut a port in the side. Problem is the amp.
Design goals will be to get as much clean volume out of 12v with minimal controls. All I need is a VOL/ON pot. I want to just plug right into it with an electric bass guitar to keep up with maybe a guitar and hand drummer.
I find amps like the Dayton Audio DTA-2 but those are for preamplified signals. I do have a Zoom B1 Effects pedal with stereo headphone level output. Even though I'd rather not use the Zoom just for simplicity, is the Dayton Audio DTA-2 actually the easiest way to go? 15 watts per channel into 4 ohms I believe, so I could get 2 4 ohm speakers for max output. The Zoom output specs are these.
Output(Line / headphones combined) : 1/4" stereo phone jack(Maximum output level : [LINE]+3dBm, output load impedance 10kΩ or higher / [headphones]20mW + 20mW, into 32 ohms load)
Am I right that the DTA-2 input wants 10K ohms or higher? Would running the Zoom stereo into the DTA-2 at say 80% volume be relatively clean? I'd have to get the highest spl speakers I can find of course.
Any other thoughts on what is the easiest way to do this? I have the soldering skills to make a couple of circuits, my problem is lack of time. I'm thinking that premade modules would even be cheaper these days.
Thanks in advance for your suggestions!
I'm thinking I can pick up a smallish funky old suitcase at the thrift store, put two high spl 4 ohm speakers in it, run it off 8 rechargeable AA's in a holder mounted inside and glue foam inside. The suitcase itself should vibrate some and give it some extra thump. I can even make it lean back or cut a port in the side. Problem is the amp.
Design goals will be to get as much clean volume out of 12v with minimal controls. All I need is a VOL/ON pot. I want to just plug right into it with an electric bass guitar to keep up with maybe a guitar and hand drummer.
I find amps like the Dayton Audio DTA-2 but those are for preamplified signals. I do have a Zoom B1 Effects pedal with stereo headphone level output. Even though I'd rather not use the Zoom just for simplicity, is the Dayton Audio DTA-2 actually the easiest way to go? 15 watts per channel into 4 ohms I believe, so I could get 2 4 ohm speakers for max output. The Zoom output specs are these.
Output(Line / headphones combined) : 1/4" stereo phone jack(Maximum output level : [LINE]+3dBm, output load impedance 10kΩ or higher / [headphones]20mW + 20mW, into 32 ohms load)
Am I right that the DTA-2 input wants 10K ohms or higher? Would running the Zoom stereo into the DTA-2 at say 80% volume be relatively clean? I'd have to get the highest spl speakers I can find of course.
Any other thoughts on what is the easiest way to do this? I have the soldering skills to make a couple of circuits, my problem is lack of time. I'm thinking that premade modules would even be cheaper these days.
Thanks in advance for your suggestions!
AA's probably won't last for more than 15 minutes at that power level.
If you are going to go that route you might consider a couple of small sealed Lead acid batteries as nicad's or rechargeable lithium's are quite costly.
jer 🙂
If you are going to go that route you might consider a couple of small sealed Lead acid batteries as nicad's or rechargeable lithium's are quite costly.
jer 🙂
Thanks for the heads up on that, you are right. I could add a switching jack and a wall wart (may already have one). As long as I can get an hour or so on batts it may work out. I already have many rechargeable AA's and a smart charger so that would keep the cost down.
I see this speaker might be good, though 6 ohm=less output but very light!
Aura NS6-255-8A 6" Paper Cone Neodymium Magnet Woofer 299-030
I see this speaker might be good, though 6 ohm=less output but very light!
Aura NS6-255-8A 6" Paper Cone Neodymium Magnet Woofer 299-030
Aurasound NS6-255-4A 6" Paper Cone Woofer 4 ohm: Madisound Speaker Store
Hi, it is good value and 4 ohm. I wouldn't use that Pyle unit for bass guitar, rgds, sreten.
Hi, it is good value and 4 ohm. I wouldn't use that Pyle unit for bass guitar, rgds, sreten.
Use an Optima car battery and a switching-mode car stereo amplifier. And two small speakers. That way you can always add another battery, plug into a car, or use a charger. Add an extra capacitor across the battery too, so automotive chargers and alternators don't add noise.
For low end, which you will need for a bass, the box the drivers are in can make a big difference. A suitcase might not cut it.
I'm thinking of a box shape so when I decide on the driver(s) I'll know what volume to shoot for. I found this one which might be a better alternative.
Goldwood GW-406D 6-1/2" Poly DVC Subwoofer Shielded 290-352
Running each channel into it's own voice coil at 4 ohms and still be way under the speaker wattage.
Goldwood GW-406D 6-1/2" Poly DVC Subwoofer Shielded 290-352
Running each channel into it's own voice coil at 4 ohms and still be way under the speaker wattage.
Guess what's going to happen to that foam surround the first time you slap the E? 😱
It's a cool idea, but if you want it to be cool in practice and not goofy:
As cyclecamper said, give up on the idea of flashlight batteries.
Put a piece of plywood inside the suitcase so you have a real baffle to mount the speaker.
Use a real bass guitar speaker, like this:
Eminence Legend BP102-4 10" Bass Guitar Driver 4 Ohm 290-470
You still might need to glue Masonite or something to the other sides of the suitcase, the cardboard will leak like sieve. You also might consider putting the preamp in your guitar - active basses are cool.
If you really want to try and get by with a cheap hifi speaker, then you need to send it a "hifi" signal - compress it, limit it, and EQ it. (All of which you can probably do with the Zoom.) But it will, at best, sound like a loud boombox. To sound like a musical instrument, you need a musical instrument speaker.
It's a cool idea, but if you want it to be cool in practice and not goofy:
As cyclecamper said, give up on the idea of flashlight batteries.
Put a piece of plywood inside the suitcase so you have a real baffle to mount the speaker.
Use a real bass guitar speaker, like this:
Eminence Legend BP102-4 10" Bass Guitar Driver 4 Ohm 290-470
You still might need to glue Masonite or something to the other sides of the suitcase, the cardboard will leak like sieve. You also might consider putting the preamp in your guitar - active basses are cool.
If you really want to try and get by with a cheap hifi speaker, then you need to send it a "hifi" signal - compress it, limit it, and EQ it. (All of which you can probably do with the Zoom.) But it will, at best, sound like a loud boombox. To sound like a musical instrument, you need a musical instrument speaker.
Well, after looking around for other folks doing this (suitcase bass amp) I have come to the conclusion that the reason no one has done it is that it will sound like c**p! Bass cabs sound best when they are very ridged and I doubt I could brace a suitcase enough so as not to sound like mush!
Thanks for the help anyway, maybe someone else will give it a go.
Thanks for the help anyway, maybe someone else will give it a go.
I have a project like this on hold at the moment. I am using 36 laptop cells split into two battery packs giving two 146w/h packs which should last around 3-5 hours each depending on use. The amplifier was chosen to be the AMP11 kit (36V) from the 41hz website and the enclosure looks to be fibreglass with a wooden frame.
What I think I'll do is investigate this further but use a wood box as the cab instead of a suitcase (unless I find a wooden box suitcase!). Even an old hifi speaker cab would work for that and it can be reinforced/sealed easily.
As far as using AA's I bet it could work if I used an amp below 10 watts. With an efficient speaker that would likely get me enough volume. I have tried my bass through a couple of very small battery guitar amps and at least it can be heard but is not clean. I tried a little Smokey Amp into a sub box from a PC sound system and it was louder than I thought it would be.
Re-purposing is fun anyway!
As far as using AA's I bet it could work if I used an amp below 10 watts. With an efficient speaker that would likely get me enough volume. I have tried my bass through a couple of very small battery guitar amps and at least it can be heard but is not clean. I tried a little Smokey Amp into a sub box from a PC sound system and it was louder than I thought it would be.
Re-purposing is fun anyway!
It lives! I found an interesting assembled module an am waiting for details on the input specs.
QKits Electronic Kits: FA617, Mono Power Amplifier, Tone Control, Volume
Other than that I poked around the parts bin and found I have a 12v 1A wall wart and a couple useable test speakers and some thin plywood to make a baffle. Next week I'm visit a couple of thrift stores and see what out there.
I can use the wall wart at first then experiment with batteries later.
QKits Electronic Kits: FA617, Mono Power Amplifier, Tone Control, Volume
Other than that I poked around the parts bin and found I have a 12v 1A wall wart and a couple useable test speakers and some thin plywood to make a baffle. Next week I'm visit a couple of thrift stores and see what out there.
I can use the wall wart at first then experiment with batteries later.
Good luck! Given what it will look like, you'll likely get a fair-sized pass on the tone. No one will expect it to sound like an Ampeg, and a funky, rattly sound can fit with several styles of music.
I'd go with an array of D type batteries, as used in many portable amps.
I'd go with an array of D type batteries, as used in many portable amps.
I picked up a medium suitcase yesterday at the Goodwill shop. It's stiff blue plastic with no interior cloth so I only had to remove a plastic frame which just popped out. Interior size is about 20 x 14 x 6 (about a cubic foot) and rectangular. There is enough room on the side for a 10 but I ordered the following based mainly on price and weight.
Peavey 8" Guitar Speaker 4 Ohms 70777082 299-202
It's not really a bass speaker (80-10K) but once it's broken in it should have enough thump for lite bass duty. I will get some plywood for each interior side and just bolt them in. That should stiffen things up nicely. Then glue some foam all around to dampen it. I might even port it, but it's a low watt speaker so maybe not, plus I'd just be guessing the size unless I go nuts with software design.
Another reason I grabbed this suitcase is it has a full aluminum channel I can add a strip of foam into for additional sealing.
At first I'm just make it a speaker cab and try it with my battery amps. Later I could build in a small amp or look around for a small head that could fit inside. Maybe even a folding leg to tilt it back. With DIY, there are no rules!
Once I get something together I'll post pix.
Peavey 8" Guitar Speaker 4 Ohms 70777082 299-202
It's not really a bass speaker (80-10K) but once it's broken in it should have enough thump for lite bass duty. I will get some plywood for each interior side and just bolt them in. That should stiffen things up nicely. Then glue some foam all around to dampen it. I might even port it, but it's a low watt speaker so maybe not, plus I'd just be guessing the size unless I go nuts with software design.
Another reason I grabbed this suitcase is it has a full aluminum channel I can add a strip of foam into for additional sealing.
At first I'm just make it a speaker cab and try it with my battery amps. Later I could build in a small amp or look around for a small head that could fit inside. Maybe even a folding leg to tilt it back. With DIY, there are no rules!
Once I get something together I'll post pix.
Well, I poked around the Net and found several design sites. They all say basically the same, this speaker in this enclosure will roll off at around 80hz but with a could db spike around 100hz The port calculators were interesting saying that if I put a small port (.25-.5 in) with length of about the same (thickness of baffle) I'd get reinforcement at 40-60 hz. Variable is the actual interior volume.
It will sound "unique" for sure!
It will sound "unique" for sure!
Funnily enough, as a kid back in the 60's I built a valve amplifier in an old suitcase - it used a 6BW6, an EF80, and a metal rectifier.
All parts (including the suitcase) apart from the mains transformer I got from a local tip, where we used to play as kids.
I think I've still got the suitcase somewhere, but it's got an elliptical hole in the top 😀
All parts (including the suitcase) apart from the mains transformer I got from a local tip, where we used to play as kids.
I think I've still got the suitcase somewhere, but it's got an elliptical hole in the top 😀
I think 4 of those drivers could make quite a punchy little unit on the Cheap open or closed !!!
jer 🙂
jer 🙂
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