Building a portable speaker

[Maker]

I have been challenged to do the above. It's because I said the Beats pill has poor bass, my friends all retaliated saying how great Beats audio is, blah blah blah. Anyway, I (Maybe quite foolishly) said I could build a better one, they bet I couldn't so now if I make a good speaker, I get £20 (Next to nothing compared to what I'll spend on it but that's beside the point).

I'll be building everything; cabinet, amp, crossovers...

It needs to be portable, I think the biggest I could probably go would be about 4" x 4" x 10", roughly the same size as the big jambox. I'm currently thinking of an upright thing with tweeters and midrange drivers facing left and right and a single low range driver on the front but nothing is for certain yet.

I'm on a very tight budget so I need recommendations for decent, yet cheap, components. I don't know if the cabinet should be just a box holding everything or some fancy thing with ports and all that nonsense, considering it'll be used outdoors and really just needs to be loud. I don't know what wattage speakers I should be looking it, preferably quite low I think as it'll be battery powered.

Any good reading material regarding this? Any thoughts?

 

[julianthegypsy]

No idea, but it sounds like a great project!

 

[Maker]

No idea, but it sounds like a great project!

I'm glad to hear that, I was half expecting "You have no idea what you're getting yourself into...".

 

[normspanners]

I built a couple of light?? 'portables' using car speakers with combined mid and tweeters in the centre of the main bass unit using old plastic speaker housings with plenty of sound deadening.
is it to be battery powered ? coz that is where your bass problem starts I was going to use a car cd player mounted in the back then you would have 50w per channel be able to play cd's if you remember them and have blue tooth and sd reader etc and run it off 12v
But I bought these in black if you want bass these are the dogs they are sick, took them on holiday, they just fit in my cabin bag. only 20w but man they kick ass. My lad thought they were 100w.
http://www.ebay.co.uk/itm/QTX-Sound...647?pt=LH_DefaultDomain_3&hash=item20e10b7fa7

Oh and BTW "You have no idea what you're getting yourself into..."

I like it loud too just come from acdc in glasgow
These are their portables on either side of the scaffold --------

----------they use 20 artics----------- but they are portable
thats why I'm deaf now --- I SAID ---THATS WHY --- I'M DEAF ----E'H?
Mind you they do have ten cannons going off for the final---- for those about to rock (we salute you) ---BOOM!!!

1:49:20 - For Those About to Rock (We Salute You)

 

[Rocketman]

You will struggle to beat it I would think, the size of the unit 4"x4"x10" is tiny when you consider you need to get the amplifier, batteries and not forgetting the speakers into it. Fun project though. Dimensions 6"x6"x12" would help a lot

 

[richie00boy]

Yes the Beats stuff has poor quality bass (and sound quality in general), but to the man on the street it is fine and bassy. You have set yourself a bit of a tough project. Proper speaker design takes years of learning.

My friend sells these which would be ideal. You would need 2 or 3 depending on whether you can get away with a 2 way design.
http://www.io390.co.uk/product/25w-amplifier-v2

Getting drivers here is the hard part. In the US there is an amazing selection if you are willing to buy from there. I would make the unit run off a laptop adaptor (19V).

 

[Maker]

Dimensions 6"x6"x12" would help a lot

I could stretch to that if need be.

 

[Rocketman]

Yeah now you can get proper 4"+ drivers in. I would tend to go for drivers like in kef speakers with tweeter in the middle - uni q. Anything going on the bay second hand maybe? You could get car speakers as mentioned but I would hazard a guess the kef's would be a better starting point.

 

[Maker]

Yes the Beats stuff has poor quality bass (and sound quality in general), but to the man on the street it is fine and bassy. You have set yourself a bit of a tough project. Proper speaker design takes years of learning.

My friend sells these which would be ideal. You would need 2 or 3 depending on whether you can get away with a 2 way design.
http://www.io390.co.uk/product/25w-amplifier-v2

Getting drivers here is the hard part. In the US there is an amazing selection if you are willing to buy from there. I would make the unit run off a laptop adaptor (19V).

Those look good, thanks for that. How would I use more than 1 though? Wire them in parallel?
There's a 20 watt integrated amplifier I like the look of, mostly because it has pots to adjust bass and treble but it is only 20 watt though.

 

[richie00boy]

You would make an active crossover to split the high and low frequencies and then feed each amp module with the appropriate signal. You don't really need tone controls, mostly a gimmick.

That TDA2005 module won't be as efficient as the class-d module, and made as shown it will have limited bass.

 

[HughF]

Get yourself over to the 12v section of speaker plans forum. There's the development thread for the mini rig on there, just copy that

 

[Maker]

You would make an active crossover to split the high and low frequencies and then feed each amp module with the appropriate signal. You don't really need tone controls, mostly a gimmick.

That TDA2005 module won't be as efficient as the class-d module, and made as shown it will have limited bass.

Can you recommend a suitable crossover?
What should the power (wattage) of the amp be compared to the speakers? The speakers all have a max power and RMS power, which is typically half the max power. Should the amp be the same as the total of the max powers of the speaker?

Get yourself over to the 12v section of speaker plans forum. There's the development thread for the mini rig on there, just copy that

I'll have a look in a second.

 

[Maker]

I might not bother with a dedicated sub, just have a tweeter and a sub on the left and right, it seems far easier.
What do you think of this sub and this tweeter?

 

[Rocketman]

Would it be any better than just running a pair of these drivers though and just forgetting about a dedicated sub driver?

http://www.ebay.co.uk/itm/KEF-Q-Ser...9&pid=100005&rk=4&rkt=6&sd=231425640824&rt=nc

If you got them for £20 it would be a rather good deal for those drivers and the tweaters are in the middle.

 

[MattF]

I was half expecting "You have no idea what you're getting yourself into...".

That's the part you'll come to realise when you're halfway through it.

No idea what I have knocking about, but if you want to hold off ordering owt for a few days, I can have a dig round and see what amplifier chips I might have shoved in the drawers. Seem to recall holding onto a few incase I ever needed them for owt. Finding them's a different matter entirely though.

 

[Maker]

Would it be any better than just running a pair of these drivers though and just forgetting about a dedicated sub driver?

http://www.ebay.co.uk/itm/KEF-Q-Series-iQ1-Pair-of-Speakers/121690247812?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=30773&meid=c6ce4940721a4e9fa18f27a584319289&pid=100005&rk=4&rkt=6&sd=231425640824&rt=nc

If you got them for £20 it would be a rather good deal for those drivers and the tweaters are in the middle.

I've actually got a few speakers kicking about, I'll need to see what they are though.

That's the part you'll come to realise when you're halfway through it.

No idea what I have knocking about, but if you want to hold off ordering owt for a few days, I can have a dig round and see what amplifier chips I might have shoved in the drawers. Seem to recall holding onto a few incase I ever needed them for owt. Finding them's a different matter entirely though.

That would be great if you have some. I've got a nice box with loads of chips in, I just can't be bothered to find out what they all are I guess now would be as good a time as any.

 

[bill_gj]

Yes the Beats stuff has poor quality bass (and sound quality in general), but to the man on the street it is fine and bassy. You have set yourself a bit of a tough project. Proper speaker design takes years of learning.

My friend sells these which would be ideal. You would need 2 or 3 depending on whether you can get away with a 2 way design.
http://www.io390.co.uk/product/25w-amplifier-v2

Getting drivers here is the hard part. In the US there is an amazing selection if you are willing to buy from there. I would make the unit run off a laptop adaptor (19V).

I think Class D amps are definitly the way to go in temps of output per cubic inch of space. It's the only way when you need something small. There's also usually some stuff on ebay as well, just use 'class d' as your search term. Class D is, I think, what a lot of these high-ouptut car amps use and they all seem to be made to work off 12v, albeit at plenty of amps.

 

[Maker]

What do you think to this crossover?

Is there a cheap way to use bluetooth to connect to the phone, rather than an aux' lead?

 

[normspanners]

http://www.ebay.co.uk/itm/Rechargab...183?pt=LH_DefaultDomain_3&hash=item56771d6f3f

 

[Maker]

Wow, that is cheap, will it be any good though? It will be (effectively) constantly charging when in use though, does that mean it's going to catch fire like Malcolm's headlamp?