Hello guys, so I'm planning on building an ammo can boom box. I have basic knowledge of speakers and amps, but nothing too in depth. I can wire stuff really good, solder, follow directions etc. I have been doing some research, and have built bluetooth speakers, but on a small scale with your standard 3.7 volt lithium-ion batteries. Also installed plenty of car stereos and amps/subwoofers.
For this project, I want to use an ammo can and some decent 4 inch speakers ( or small oval ones, well see) I've done research, but can't find any conclusive wiring diagram so I pieced together what I think will work. I want either a toggle switch power button, or a push button on/off switch. I prefer one of those, with LED lighting. I just dont know what amp rating to buy. Most show 3 amps, but that might be too little.
I'm going to use a small sealed lead acid 12 volt battery, around 10Ah and an amp to use with it. This part I'm not sure off, how much power to buy.. I want something that will last a decent amount of time with the battery. I was thinking something 2 channel, 50 watts each. But I don't know if that is too much.. This amp looks nice, but it doesn't have a volume control.
TDA7492 Digital Audio Amplifier Board 2x50W
This one has a volume control but is pretty weak. I can de-solder the volume control and move it to the case with some extending wires, that's no issue.
PAM8610 2x10W Class-D Audio Amplifier Board
Can someone lead me to a decent amp? I want it to be loud, but clear and not too rough on the battery. Also needs some way for me to mount the volume externally on the box.
Some possible speakers, but I can check around more for those.
Pioneer TS-G1045R 210W 4" 2-Way G-Series Coaxial Car Speakers
I want something with a higher sensitivity right? Those are 88 dB. The higher, the louder they get with the same power if I understand correctly? They don't HAVE to have to tweeters, but maybe a decent pair would sound nice.
Here is the wiring diagram I made up so far. It's my initial draft, and please tell me or help make changes if needed.
I'mm have the main power cable with a 10 amp fuse right off the bat. I want the battery able to be hooked up to charge without opening it up. For that I would use something like a computer power plug or so and change the wires up. Can I charge it directly as shown, or is there a better way I can isolate it? I would LIKE it on it's own isolated circuit with switches in the correct locations, but thats a newer part to me. SPST vs DPDT etc. And should I get switches with a dedicated ground? Here's one I was looking at, just for general idea.. I just don't know if it can handle the load with the speakers going and the amps.
12V 16mm Blue LED Power Symbol Angel Eye Push Button Metal on Off Switch Sales | eBay
I'm also going to have a volt gauge, digital. Something like this
4 5 30V Mini Digital Blue LED Car Voltmeter Voltage Volt Panel Meter Gauge | eBay
The plug i'll use is this for external AUX in. I can cut up an AUX cable for the input into the amp
3 5mm 1 8" Mini Female Headphone Jack Plug Stereo Audio Panel Mount Philmore New | eBay
Help me out guys, before I go spend money on parts I may not need.
Main things I need to know is if it's okay to charge battery while connected, but powered down, or how to make it a separate circuit using switches. Maybe a 2 way rocker or so. One for charge, and other side for power. I can always add a LED inline for power if the switch doesn't have it integrated.
Second big question, what power amp? Is 20 some watts enough, or should I go 50. It needs to have some sort of volume control that I can remount if needed. If it has bluetooth, that would be a big plus, although I don't think that would work well inside a steel box anyways.
Last, should I add a small port? I've seen some ammo box designs with them, and some without.
Maybe I also might add in a power rail, with some post for + and negative to keep it clean.
Thank you so much for any advice you can give. This is my first post here and pretty long, but I want to do this right.
For this project, I want to use an ammo can and some decent 4 inch speakers ( or small oval ones, well see) I've done research, but can't find any conclusive wiring diagram so I pieced together what I think will work. I want either a toggle switch power button, or a push button on/off switch. I prefer one of those, with LED lighting. I just dont know what amp rating to buy. Most show 3 amps, but that might be too little.
I'm going to use a small sealed lead acid 12 volt battery, around 10Ah and an amp to use with it. This part I'm not sure off, how much power to buy.. I want something that will last a decent amount of time with the battery. I was thinking something 2 channel, 50 watts each. But I don't know if that is too much.. This amp looks nice, but it doesn't have a volume control.
TDA7492 Digital Audio Amplifier Board 2x50W
This one has a volume control but is pretty weak. I can de-solder the volume control and move it to the case with some extending wires, that's no issue.
PAM8610 2x10W Class-D Audio Amplifier Board
Can someone lead me to a decent amp? I want it to be loud, but clear and not too rough on the battery. Also needs some way for me to mount the volume externally on the box.
Some possible speakers, but I can check around more for those.
Pioneer TS-G1045R 210W 4" 2-Way G-Series Coaxial Car Speakers
I want something with a higher sensitivity right? Those are 88 dB. The higher, the louder they get with the same power if I understand correctly? They don't HAVE to have to tweeters, but maybe a decent pair would sound nice.
Here is the wiring diagram I made up so far. It's my initial draft, and please tell me or help make changes if needed.
I'mm have the main power cable with a 10 amp fuse right off the bat. I want the battery able to be hooked up to charge without opening it up. For that I would use something like a computer power plug or so and change the wires up. Can I charge it directly as shown, or is there a better way I can isolate it? I would LIKE it on it's own isolated circuit with switches in the correct locations, but thats a newer part to me. SPST vs DPDT etc. And should I get switches with a dedicated ground? Here's one I was looking at, just for general idea.. I just don't know if it can handle the load with the speakers going and the amps.
12V 16mm Blue LED Power Symbol Angel Eye Push Button Metal on Off Switch Sales | eBay
I'm also going to have a volt gauge, digital. Something like this
4 5 30V Mini Digital Blue LED Car Voltmeter Voltage Volt Panel Meter Gauge | eBay
The plug i'll use is this for external AUX in. I can cut up an AUX cable for the input into the amp
3 5mm 1 8" Mini Female Headphone Jack Plug Stereo Audio Panel Mount Philmore New | eBay
Help me out guys, before I go spend money on parts I may not need.
Main things I need to know is if it's okay to charge battery while connected, but powered down, or how to make it a separate circuit using switches. Maybe a 2 way rocker or so. One for charge, and other side for power. I can always add a LED inline for power if the switch doesn't have it integrated.
Second big question, what power amp? Is 20 some watts enough, or should I go 50. It needs to have some sort of volume control that I can remount if needed. If it has bluetooth, that would be a big plus, although I don't think that would work well inside a steel box anyways.
Last, should I add a small port? I've seen some ammo box designs with them, and some without.
Maybe I also might add in a power rail, with some post for + and negative to keep it clean.
Thank you so much for any advice you can give. This is my first post here and pretty long, but I want to do this right.
Hi Dan,
There is a direct connection between the power consumption
of the devices connected (speakers, amp...) and the battery life
that powers it all. The greater the current you draw from it, the less
it will be able to last and the more the speakers will be subjected
to stress. I reckon a clean 10W/channel with about 1% of THD
at 1 kHz would be enough for the speakers without getting
these damaged, maybe.
Consider the worst case speaker impedance is 4 ohms. 10W
od power would draw current of 1,6A at 6,3 Vrms. So if both
of the channels would deliver the same power all the time, a 10Ah
battery would work about 3,1 hours. Since this is probably
an overestimated power draw, your battery could last twice as
long, obviously depending on the volume setting.
The TDA 7492 chip has a span of voltages for specified power
output at certain distortion levels. Try to study its datasheet and
you will see that without a voltage step-up device, you won't be
able to get specifed higher power output with a 12 V battery.
The graph power output vs. supply voltage shows about 13W/6 ohm
for supply of 15V. Your battery has less, so the power output would drop
also. I would not expect of the boom box to perform concert loudness,
so "lower power levels" are OK, both for the battery life and damage
probability occurance.
I would seriously consider using a car stereo head unit with its chip
power whatever it can deliver, realistic 7-8 W or so.
There is a direct connection between the power consumption
of the devices connected (speakers, amp...) and the battery life
that powers it all. The greater the current you draw from it, the less
it will be able to last and the more the speakers will be subjected
to stress. I reckon a clean 10W/channel with about 1% of THD
at 1 kHz would be enough for the speakers without getting
these damaged, maybe.
Consider the worst case speaker impedance is 4 ohms. 10W
od power would draw current of 1,6A at 6,3 Vrms. So if both
of the channels would deliver the same power all the time, a 10Ah
battery would work about 3,1 hours. Since this is probably
an overestimated power draw, your battery could last twice as
long, obviously depending on the volume setting.
The TDA 7492 chip has a span of voltages for specified power
output at certain distortion levels. Try to study its datasheet and
you will see that without a voltage step-up device, you won't be
able to get specifed higher power output with a 12 V battery.
The graph power output vs. supply voltage shows about 13W/6 ohm
for supply of 15V. Your battery has less, so the power output would drop
also. I would not expect of the boom box to perform concert loudness,
so "lower power levels" are OK, both for the battery life and damage
probability occurance.
I would seriously consider using a car stereo head unit with its chip
power whatever it can deliver, realistic 7-8 W or so.
Would this amp be good? It's 15 watts per channel. Very tiny and has volume knob.
Dayton Audio DTA-2 Class T Digital Audio Amplifier Module
A car headunit would be a little big to fit. The only thing is that this amp says it needs a regulated 12 volt source. The battery would fluctuate down slowly.
As long it can push the speakers i'd be happy. If it gets as loud as a decent pair of bluetooth speakers I'd be happy.
Am I right about the sensitivity, the higher the better?
Dayton Audio DTA-2 Class T Digital Audio Amplifier Module
A car headunit would be a little big to fit. The only thing is that this amp says it needs a regulated 12 volt source. The battery would fluctuate down slowly.
As long it can push the speakers i'd be happy. If it gets as loud as a decent pair of bluetooth speakers I'd be happy.
Am I right about the sensitivity, the higher the better?
Yes, Tripath TA 2024 is a good start for your project. I wouldn't sweat
about "it needs a regulated 12V source". Battery power is pure DC,
the small drift won't do any harm. This chip is said to operate from
8,5 -13,2 Vdc, so it should push the speakers allright. The sensitivity depends
on physical driver properties and once you choose your drivers, it is what
it is. There is not much you can do about it after you set your primary
goals like available baffle dimensions, volume, cost, etc. Manufacturer
says something about sensitivity, but this is particularly true for a driver
mounted in a large baffle, and without seeing an actual frequency response
graph, you dont know to what frequency the published sensitivity aplies.
That pioneer unit appears to be solidly built. Maybe you could take into
consideraton a larger coaxial unit, TS-G1645R.
about "it needs a regulated 12V source". Battery power is pure DC,
the small drift won't do any harm. This chip is said to operate from
8,5 -13,2 Vdc, so it should push the speakers allright. The sensitivity depends
on physical driver properties and once you choose your drivers, it is what
it is. There is not much you can do about it after you set your primary
goals like available baffle dimensions, volume, cost, etc. Manufacturer
says something about sensitivity, but this is particularly true for a driver
mounted in a large baffle, and without seeing an actual frequency response
graph, you dont know to what frequency the published sensitivity aplies.
That pioneer unit appears to be solidly built. Maybe you could take into
consideraton a larger coaxial unit, TS-G1645R.
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