What speaker and amp combination for battery use?

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Downunder35m
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What speaker and amp combination for battery use?

Post by Downunder35m »

Back in the day I had a surround system using only 15 - 25W speakers.
Quite expensive ones and damn loud even in comparison to the 500W stereo system I had back then.

Now I am in need of some decent music while working.
Problem is that we need high grade hearing protection and on top of that use rather loud tools.
Common jobiste radioa are either not loud enough or if they are way too bulky.
Like the Milwaukee one that goes on their tool trolley system.
With no mains power available where I work I need something that is loud enough but won't be too much of a drain on a power tool battery.
Talking about 18V / 5AH here that need to be able to last 10-12 hours on full volume.

I have mobile MP3 speakers rated for 3W pumping out quite some loud music - on full only with the power plugged in LOL
Also some 5W speakers from and old flat screen TV producing loud noise.
Nothing compared to my old 15W Jamo speakers on just 10W though.
What I would like is just a decent amp that has no issues starting from around 18V and still being fine with around 9V - the cut off voltage for these packs.
And of course some effecient speaker.
Does not even have to be stereo for my use, just really loud and able to still produce a good sound quality.
Preferably of course in small size.

Now, i have build custom speaker system with crossovers and all in the past.
Never though for such a purpose, always with pure sound quality in mind.
No real clue what full range speaker to select as it is hard to find any usuable reference telling you how loud that thing is.
For these ready to go amps from china and such It seems they all come with a wide volatage range.
but not allow to actually use them across this range.
Means the power output and best speaker (4, 8 or 16 Ohm) to attach depends on the operating voltage :(
I guess ideally I would use something running on 9-10V with some step down converter that cuts the power off when the battery runs too low.
With the easy to calculate 10V a 15W speaker with a 10W amp would require a bit over 1 amp to run.
With hearing protection it would be really nice to be able to adjust the output like with some equalizer or lest seperately for bass, mids and highs.

And before you say to grab a protable boom box or bluetooth speaker:
I really need it small AND loud enough with a battery runtime on full blast of about 10 hours....
So no huge speakers, big amps and heavy battery packs to connect to....
I have to make it work with a one 18V/5AH battery for this time.
Any suggestions or products you can recommend?
Exploring the works of the old inventors, mixng them up with a modern touch.
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liquidhandwash
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Re: What speaker and amp combination for battery use?

Post by liquidhandwash »

You're in Oz, right? I do have a big box full of MacBook pro batteries, they are quite easy to mod and fit a cheap BMS to, if you want to pay the postage I can send you some. According to my Macs info page, they are a bit over 5AH at 11.1 volts but my multimeter says they are12 volts or more.
Downunder35m
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Re: What speaker and amp combination for battery use?

Post by Downunder35m »

Thanks for the offer, I might get back to on that one for a later project.
Right now I am just trying to figure out how to get the best boom from a power tool battery.
Power tool because I have to charge the ones for my tools at least twice per day anyway ;)
found a nice full range speaker, rated for 15W and just 3" in diameter.
With a fully enclosed driver, so need to hassle around with proper box dimensions.
But it is just over 80 bucks - plus postage from US of A :(
I have no problem finding really decent spearks for normal sized speaker boxes or car use but going small....
And alternative I was considering speakers for guitar amps but they won't come in small sizes either LOL

Obviously there is no need for a High Fidelity amp if you use hearing protection of at least 32DB and constanly rattle around with your impact driver....
I am aware of many of these audio amp chips that require little to no external components but can't afford the time on making ciruit boards and all.
Means I would love to get a single speaker with a size of not more than about 10cm in diameter paired with a simple amp that accepts a stero input and is capable of providing a proper mono output.
Preferably similar to car amps where you can "bridge" a channel to get mono output with twice the power.
But it seems I am getting too old to find some small speaker that is really loud and can tolerate these levels for a whole day and not just as a peak spike here and there.
I might have to get one of these portable boom boxes with mpr and lossless support and salvage it for parts ROFL
Exploring the works of the old inventors, mixng them up with a modern touch.
To tinker and create means to be alive.
Bringing the long lost back means history comes alive again.
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Orngrimm
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Re: What speaker and amp combination for battery use?

Post by Orngrimm »

I am aware of many of these audio amp chips that require little to no external components but can't afford the time on making ciruit boards and all.
hey, i could design you one if you want. I would also drop in the PCB-manufacturing and the postage to you. Component-ordering and assembly would be up to you.
If interested, post again :)
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Downunder35m
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Re: What speaker and amp combination for battery use?

Post by Downunder35m »

Sound great, THANK you!
But I am still worrier or confused when it comes to finding the right speakers.
Was in quite some dental pain this week until my dentist could fix me (somewhat anyway).
But I went through some old speakers that have no real purpose anymore other than for salvage.
Used the little MP3 player module I have to test them out on the max 3W the tiny thing claims to have.

First thing I noticed was that despite my preference in the real audio world, 8 Ohm speakers are not really producing much.
4 Ohm speakers, at least in my little test, seem to provide a bit more output.
But of course they also start clipping and crackling much earlier when cranking the volume up.
I take it as an indication that for seriously loud volumes 8 Ohm speakers with some power to spare would be better than 4 Ohm.
A bit confirmed as well by the the slightly lower power consumption I measured.

But here is the thing I just totally fail to understand:
I have some surround speakers, a pair from Bose, rated at just 10W and one pair from Jamo, rated at 15W that I tried on this 3W amp.
And both are loud as....
Nothing compared to the still not loud enough Makita jobsite radio but a huge difference compared to all those cheap speakers I have around.
We have some DJ-audio-lighting shop in town with a helpful guy running it.
Had a chat with him before he closed shop for easter.
The guy says that if I need speakers loud enough enough to overcome hearing protection and loud tools properly I have to go at least 15cm in diameter and at least 25W - 50 Peak.
And in terms of using full range or wide band speakers as a single .... :(
Appearently none of them cope well as a single with music and vocals together.
The low frequency boom boom will overlap with the vocal and turn them "soggy".
And of course he could not give any usable recommendation for some smaller speakers (in size, not power).

When looking for some amp with a wide voltage range I found this weird thing: Ebay
I admit I like it because of the volume knob being in the center....
But it seems to have some nice features.
Does not have the TF card support to use it directly as a player but the connectivity options are nice and the desging too, me think ;)
No problem to hook up the Mp3 player with a cable, so I would be fine here.
Means I would only have to worry about getting a clean 12V from the 18V battery pack and some protection circuit to shut all off if the voltage drops below the limits.
But an output of still 15W here means I need suitable speakers that won't be harmed.

A speaker like this should do it with a little crossover and piezo added to cover the high frequencies.
But they are TINY any no clue how loud they actually are.
About the same size and cone shape of what all these portable speakers seem to have and well, the ones I tested, from cheap to over 200 bucks are not loud enough.
I guess about 10-15CM in diameter or doubling up is the only option.
Will keep hunting for a bit and hope I find some nice speakers for little money.
Exploring the works of the old inventors, mixng them up with a modern touch.
To tinker and create means to be alive.
Bringing the long lost back means history comes alive again.
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