Bike Trailer w/ Sure TK2050 & B212XL PA

[Islander108]

Hey everyone,

I'm pretty new to this, but I've learned a lot from this forum already. I have an idea of the setup I want, but I'm sure it could use some critiquing.

I am attempting to build a battery-powered live sound system to pull in a trailer behind my mountain bike. It will be used in a weekly bike-party over the summer and in lot parties at music festivals. Here's what I'm thinking:


Batteries
2x 12v SLA batteries, mounted under the trailer deck for stability. (I have plenty from old UPS's at the office.)

Amp
For an amp I am thinking the Sure 4x100w TK2050 board from parts-express. This will start as a mono setup with 1 PA speaker, I may add a second PA if I feel there is a need.

4x100W @ 4 Ohm TK2050 Class-T Audio Amplifier Board Only | 320-335

Speakers
It's my understanding that passive PA speakers will be the most efficient for this type of setup. I am leaning toward the Behringer B212XL Eurolive 12" PA speaker. I am not opposed to building my own box and choosing other speakers, but I live in an apartment, space and tools are limited.

Behringer B212XL Eurolive 12" 2-Way PA Speaker System | 248-6476

Mixer
So here's where I get confused. If I have a small powered mixer, like the one listed below, do I need a crossover? with 4 channels, could I not provide seperate inputs to the 12" and tweeter, then use the EQ settings to adjust the levels in place of having a crossover? Like I said, I'm a little new to this.

http://www.amazon.com/Behringer-302...&ie=UTF8&qid=1392857178&sr=1-5&keywords=mixer


Any suggestions or advise for this project would be much appreciated! Thanks!

 

[lutkeveld]

A mixer is not a replacement for a crossover. The crossover is already built-in in the speaker. The only filter that could be added is a HPF to limit excursion at lower frequencies.

 

[Islander108]

Okay, how would this affect efficiency? It's my understanding that if efficiency is paramount, it is ideal to put the crossover before the amp. Is this true? would it be advisable to mount the amp in the speaker cab and wire it inline, after the crossover?

 

[Nummisoft]

Using crossover before amp is ideal, but you could't use the same crossover parts from the speaker you are going to use. You would have to design the whole crossover from the start. The difference in efficiency is so small, that I would't try to do that.

 

[Nummisoft]

I read your question wrong. HPF is good for efficiency and it should be before amp.

 

[bitSmasher]

There's some good info to be read in another site's"12v powered systems" forum, you'll also find plans for speakers too - plenty of portable and bike drawn discussions

Those Behringer boxes will work, and you don't need to worry about external crossover
For what purpose is the mixer? Might not even need that either - keep things very simple to start with but also be mindful of expanding in the future

Also, don't get too caught up on stereo sound. Nothing wrong with running 2 speakers, that's for sure, but you can always run mono to keep it compact

 

[Islander108]

Thanks for the advice gentlemen! @bitSmasher, definitely going mono to start. I only have the one B212XL at the moment. I'm not sure the mixer is neccessary either. I was thinking I would probably need to EQ the input somehow... But I suppose that can be done on MP3/phone I will be using as a source. I also would like to find a way plug other peoples systems into my input, because when we congregate at the end there is about 6-8 systems blasting different music. It would be cool to get 2 or 3 systems chained together, playing in unison.