Speakerplans.com Homepage
Forum Home Forum Home > General > 12v Powered Systems
  New Posts New Posts RSS Feed - first build, portable boombox advice please
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

first build, portable boombox advice please

 Post Reply Post Reply
Author
Message
elnoss View Drop Down
New Member
New Member


Joined: 05 September 2018
Location: Melbourne
Status: Offline
Points: 2
Post Options Post Options   Thanks (0) Thanks(0)   Quote elnoss Quote  Post ReplyReply Direct Link To This Post Topic: first build, portable boombox advice please
    Posted: 18 September 2018 at 3:37am
Hi there,

So I am relatively new to speaker building, discounting any work done on basic car stereo wiring and the like. Considering this, my project is maybe quite large - I want to build a medium to large portable boombox powered by 12v sla batteries (24v output). This may be a lot of info - although I am new I believe I have thought this through a bit.


The boombox needs to be above all things loud (apart from actually working), with not too much emphasis on refined ‘HiFi’, and I'd like a relatively punchy lower end (for bass heavy music, able to be taken camping/to festivals/wherever). I am happy for the speaker to only handle mono. Weight and size not really an issue as it is gonna be big and heavy anyway. The parts list from Parts express comes at the moment to around $325 before assembling, which is within my budget.


Also as stupid as it may be, a lot of the design stems from the aesthetics of the two woofers/tweeters around the big sub, if that seems silly let me know why.


I have designed a box for the drivers and batteries to all sit in (to be made of 18mm MDF) and have done a fair bit of research trying to teach myself further than high school physics about basic concepts involved with making speakers. The design involves one sub, two woofers and two tweeters, all in seperate compartments.


With this research and model created, I have selected a group of parts and an amplifier (parts list below). The amp puts out 2x50W +1x100W all at 4ohms. I was planning on wiring in parallel two 8ohm tweeters (80W RMS, 100dB spl) with an assembled 3500Hz HP 4ohm crossover before them from one 50W output, and also in parallel two 8ohm woofers (100W RMS, 89.4spl) with two crossovers, a 100Hz HP 4ohm, and 3500Hz LP 4ohm. Does it make sense to use a 4 ohm crossover for two x (two 8ohm drivers wired in parallel) as the amp is putting out 4ohms? The sub is a 12”, 250W RMS 4ohm and would be wired by itself with a 100Hz crossover.


Would the amp mentioned have enough power for the system I have described? I chose it because of price point/controls/size/bluetooth compatibility. Does what I have gone over make sense? This would be a project to complete before summer (end of the year here) so I have time. I have also read that I will need an L-pad to account for the higher sensitivity of the tweeters, and planned on wiring that in after the crossover, before the two tweeters. Is this also correct? Would it need to be 4ohm or 8ohm?


I have thought of including a nice needle voltmeter and other such aesthetic/practical hybrid additions as solid switch-operated LEDs and maybe a USB power out to charge a phone. I have planned on using perhaps used SLAs/car batteries in series/parallel as required and possible - the boombox wouldn’t be running too much, a couple of hours a day for a couple of days (reasonable?). Theoretically charged by hooking the batteries up to an idling car’s battery a la jump starting (feasible?), as well as from a 12v wall charger.


I ask for recommendations and any comments and general help, thanks heaps for reading and in advance for replying. 


Pics of speaker design:

https://imgur.com/a/CC8u563 - https://imgur.com/a/CC8u563


Here is the parts list:


Amp:

https://www.parts-express.com/tps3116d2--d-21-bluetooth-40-amplifier-board-2-x-50w-100w-with--and-volume-con--320-635 - https://www.parts-express.com/tps3116d2-class-d-21-bluetooth-40-amplifier-board-2-x-50w-100w-with-filter-and-volume-con--320-635

Subwoofer:

https://www.parts-express.com/dayton-audio-dcs305-4-12-ic-subwoofer-4-ohm--295-204 - https://www.parts-express.com/dayton-audio-dcs305-4-12-classic-subwoofer-4-ohm--295-204

Woofers:

https://www.parts-express.com/peerless-850544-6-1-2-composite-cone-csx-woofer-8-ohm--299-2317 - https://www.parts-express.com/peerless-850544-6-1-2-composite-cone-csx-woofer-8-ohm--299-2317

Tweeters:

https://www.parts-express.com/pyle-ph44-4-x-4-horn-mid-tweeter--272-102 - https://www.parts-express.com/pyle-ph44-4-x-4-horn-mid-tweeter--272-102

Crossovers:

https://www.parts-express.com/100-hz-high-pass-4-ohm-crossover--266-460 - https://www.parts-express.com/100-hz-high-pass-4-ohm-crossover--266-460

https://www.parts-express.com/dayton-audio-35k-lpf-4-low-pass-speaker-crossover-3500-hz-12-db-octave--260-1888 - https://www.parts-express.com/dayton-audio-35k-lpf-4-low-pass-speaker-crossover-3500-hz-12-db-octave--260-1888

https://www.parts-express.com/parts-express-100-hz-low-pass-4-ohm-crossover--266-444 - https://www.parts-express.com/parts-express-100-hz-low-pass-4-ohm-crossover--266-444

https://www.parts-express.com/dayton-audio-35k-hpf-4-high-pass-speaker-crossover-3500-hz-12-db-octave--260-1886 - https://www.parts-express.com/dayton-audio-35k-hpf-4-high-pass-speaker-crossover-3500-hz-12-db-octave--260-1886

L-pad:

https://www.parts-express.com/speaker-l-pad-attenuator-100w-mono-1-shaft-8-ohm--260-265 - https://www.parts-express.com/speaker-l-pad-attenuator-100w-mono-1-shaft-8-ohm--260-265

< ="text/"> p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Helvetica Neue'; color: #454545} p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Helvetica Neue'; color: #454545; min-height: 14.0px} p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Helvetica Neue'; color: #e4af0a}
Back to Top
JonB67 View Drop Down
Young Croc
Young Croc


Joined: 22 April 2016
Location: UK
Status: Offline
Points: 1376
Post Options Post Options   Thanks (0) Thanks(0)   Quote JonB67 Quote  Post ReplyReply Direct Link To This Post Posted: 18 September 2018 at 7:20am
Theres a boombox called the boominator that's a similar idea to what you're planning (and i believe someone built a half one they called a halfinator)

Ive not read the threads fully as it's not really what i need but i bet there's loads of useful info in the threads if you wanted to dig them out.  

If you're dead set on your own design and not building something that's been tested and measured you'll need to model it in winisd, hornresp  or similar speaker modelling software to make sure you get it the correct volume.
Back to Top
Shortrope View Drop Down
Young Croc
Young Croc


Joined: 08 July 2013
Location: Ireland
Status: Offline
Points: 1232
Post Options Post Options   Thanks (0) Thanks(0)   Quote Shortrope Quote  Post ReplyReply Direct Link To This Post Posted: 18 September 2018 at 8:04am
The Boominator or Halfinator is really what you should build...it will fulfil all your criteria and then some.
I say this from experience of building and owning one myself and helping on the build of two more.
My Tinnitus is coming along nicely!!
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.145 seconds.