Retro-look ipod speakers

[bdw02c]

Hi folks. I'm new to the forum and new to diy audio in general. I've found the information on the Boominator and similar projects to be inspiring and invaluable. I am planning a similar project-- though mine wont be portable.

I've got an old speaker case that I want to repurpose and fit with with a t-amp some new woofers/tweeters inside and an ipod or laptop source. Retro look with 21st century sound and size is my goal.

It sounds like everyone likes the assemble yourself 41hz t-amps but I'm really not comfortable doing that. I am considering this first effort a prototype so I am going to be as economical as possible.

Dayton DTA-1 to power it.
Dayton B652 speakers (it seems better value to get these and disassemble them rather than buy the woofers and tweeters separately)

I plan on fitting both woofers and tweeters into this old cabinet.

My big question is about a crossover. My understanding of them is extremely crude. It seems like many bookshelf speakers don't even utilize them. Should I integrate one or will I not gain much with this speaker setup?

I guess I also need to decide whether to seal it or not. I would like to conceal the DTA-1 inside the case. If I seal the case I could put a switch on the outside to power it. Maybe control volume from the ipod? I wonder if heat will be an issue though with the amp inside (though I understand these run extremely efficiently).

Clearly, I'm not an audiophile. I really want to get a retro look as much as quality sound. If it sounds a good as the altec lansing ipod dock I had I'll be extremely happy.

Any advice, direction, or links to similar projects would be appreciated.

[Pano]

Sounds like a plan! I don't see any major problems.

You can use the crossover that ripped out of the B625 in your new box.
Signal has to get from one speaker to the other, but that's no big deal.
Amp heat should be be a problem. You can always add some metal to the existing heatsink if you're worried. It won't take much.

[bdw02c]

Thanks for the quick response. I didn't realize the B625 would have a crossover in it.

Now that I think about it, I will probably just go with an amplifier board (like the Sure 2x25w Class D). If I am going to conceal it in the unit there is no reason for the alum housing. However, these boards don't have a volume control. Any advice on using a rotary encoder or potentiometer to control volume? Advantages of each? I see that Sure makes a rotary encoder but can't find any information on how this wires into the amp.

Thanks

[Pano]

I'd just use the iPod volume control. I don't think it has enough voltage to overdrive the Sure amp, in fact it may never hit full power.

There are a lot of users of the Sure products here who can tell you. Or you can search the threads.

[Buckapound]

Like Pano says, you're on the right track. Be sure to leave some kind of hatch to access the innards, as it seems like there's always some tinkering to do. Computer memory chip heat sinks (stick-on) are all you need. Those amps are very efficient, meaning they have very little waste heat.

At some point you'll have to make some decisions as a speaker cabinet: sealed, ported, whatever, and make some attempts to tune it. I would look for plans for those drivers and see what the general outline is for their best use and come as close as you can. You can do some tuning (port lengths for example) by ear.

Adding a volume control is no big deal, and might be useful if you ever think you would want to hook up something w/o one, or want to get the better sound and longer battery life when pulling the signal from the line-out through an iPod dock connector. You just need a dual 50K audio taper (logarithmic) potentiometer. Alps is a good brand, should be easy enough to find one on eBay or from an electronics place like Mouser. Hooking it up is simple. As I recall, there were diagrams on this thread:

Sonic Impact 5066 Parts List & Modifications

Aah, memories!

If you have an electronics surplus place in your town, they are great resources for retro volume knobs, switches, pilot lights and that kind of functional bric-a-brac. Don't know what kind of case you're using but sometimes those old boxes can benefit from additional stiffening, bracing, sound absorbtion, and the like.

--Buckapound