looking to buy a modern boom box

And you'll find these things dont have full output on batteries , mine is certainly louder on the mains , which is understandable. Still plenty of clout for most little garden gatherings etc etc

Saturnus wrote: Hemisphere wrote: http://www.ebay.co.uk/itm/Sharp-GXM10HOR-Boombox-Entertainment-Stage-Sound-System-100W-X-Bass-USB-Open-Box-/281040839651#vi-content 1,250 Watts!!!!! ;) Seriouly though for 99 quid it looks worth a shot if pre-made Boombox is what you're after, and if it really does output 100w RMS as it claims that could easily be re-routed into some beefier speakers (even additional external boxes/subs etc - 100w into some PA speakers can give a massive output!) At least it's got bright orange lights that flash when the bass speakers play so you know when there was supposed to be bass. Probably because you wouldn't otherwise know. That's about the most useful feature of that £99 doorstop I reckon. If that boombox really did 100W total output then the designers are prime Darwin Award candidates as that would be phenomenally stupid on an epic scale as that would mean the batteries would last less than 17 minutes if you wasted quality alkaline batteries on it.

Obviously 100w RMS translated for marketing speak would mean (at best) 100 watts peak amplifier output before unacceptable distortion, so the speakers would see something like 15 watts true RMS signal. 

Edited by Hemisphere - 21 April 2013 at 5:04pm

My guess is that Saturnus has not heard the JVC boombox recently as the sound is really pretty good. It'll never sound hifi but it's still impressive, I prefer the sound of the boombox to the minirig, but the minirig wins on most other fronts. The only criticisms I have are that the battery life on D size is pityful, and the plastic end caps are too hard and should have been made from rubber or at least ABS.

Saturnus wrote: biotec wrote: My guess is that Saturnus has not heard the JVC boombox recently as the sound is really pretty good. I heard one of the new models about 3 weeks ago. Not much change in sound quality. A slight turn for the worse in the bass, and some  improvements in midrange but still pathetic considering the price.

Someone I know picked up (old version of)  that JVC thing .... 20 quid because the CD player bit was knackered. He was running it from a sizeable SLA battery + inverter (because he hadn't spotted the 12V DC connector )

Anyway it made a reasonable amount of noise and boom for the size I guess .... but I'd agree that you don't have to try that hard to make something better and a good deal more power-efficient.

I think they use 10 x D-cells ...... which if alkaline would be 15V when fresh. Seems highly likely that the "12V" connector would hook into the circuit same place as the internal battery terminals.
But its known that they're "louder on mains power" ...... so we could probably assume that the internal power rail would be around 18-20V when running on AC (which sounds about right for the power ratings I think).
In the context of playing a bit of music on an outdoor market stall .... well its OK - reasonably convenient, but likely pretty poor power efficiency.

i got these last week and they are amazing .. sound is crystal clear, bone crunching bass.. one bad thing is tho it cost loads to run for D Batterys 

As the OP says 'modern boom box' .Why the hell would you want to spend £200+ on making one(not forgetting the time and effort) when you can get a decent 'portable' for under £50!(what I paid for my tape deck JVC for example....) He's not having a rave! If the boominator is that good, how comes I have never heard of anyone owning one( no disrespect). It's probably coz they want exactly that what is stated in the OP, a modern boombox.