Boom Box design theory

duanebro

I have wanted to design a boombox for some time. I did actually build one with vifa tc9 drivers. But I wasn't thrilled with it. The point of this post is to help me understand comb filtering with to drivers so close together. Walking in front of the last one sounded strange. I assume this was from interaction of the sound waves coming from the drivers being so close together. I wonder if this could be improved by angling the drivers away from each other. Or putting them on the sides of the enclosure. Has this been discussed to death elsewhere? 

Thanks!

jr@mac

Duane,

I really don't have much to offer other than to suggest going with a 2-way design rather than a full range design if possible. 

duanebro

The next one will be. I was just using what i had on hand last time. Or at least wide band drivers with a "sub"

Mzisserson

Heh. I see all of these "boomboxes" and wonder why more attention isn't paid, however for many of them, slapping a couple of full rangers in a box with a sure amp serves the purpose. 

One of my design team projects was going to be a "hifi" portable boom box, but I lost the luster since it will require effort I decided would not be worth the reward. 

The other thing with boom boxes is they have a steep build cost. Its pretty inexpensive to slap one together, but to get some real power and fidelity requires bigger amps/batteries etc. 

Likely why close enough is good enough. 

PWRRYD

I'm designing one right now for a friend at work.  He wants something to use around the fire pit when they go camping.  He has a camper so 120v and an extention cord is his desire instead of batteries.  Makes things a lot easier.  But yeah, it'll just be "stick a couple ND90's in boxes with a Lepea amp" and his phone as the source.  Nowhere close to hifi, but much better than most off the shelf stuff.

Mzisserson

PWRRYD said:

I'm designing one right now for a friend at work.  He wants something to use around the fire pit when they go camping.  He has a camper so 120v and an extention cord is his desire instead of batteries.  Makes things a lot easier.  But yeah, it'll just be "stick a couple ND90's in boxes with a Lepea amp" and his phone as the source.  Nowhere close to hifi, but much better than most off the shelf stuff.

Much better than the other stuff! Still a lot of bang for the buck. 

D1PP1N

The boombbox i jist built cost me like $225. Of you buy a 2.1 amp its like $75 of that. Its two 3" full rangers and a tang band 5-1/4 sub. Its pretty loud and the bass is good. It has bluetooth that has an okay range so that is convenient to switch songs and adjust volume.