speakers for a wierd cabinet

[sky12345]

I built 2 odd shaped cabinets for speakers that I want to use on my diy computer jukebox. I am new to making speakers and now that I have actually looked at speaker information I see that I should have figured out what speaker I wanted to begin with and decided the size of the cabinet based on the speaker, but I did it backwards. The speaker cabinets are 17" tall by 7 3/4" wide on the outside and the inner dimensions are 16" tall by 71/4" wide minus a 3/4" horizontal brace in the center. I have posted a quick drawing of the top view of a cabinet.
Can you help me decide what speakers to use in the cabinets? These are external speakers for the jukebox and I already have good speakers in the cabinet of the jukebox so I would like to go with some of the cheaper ones. They will be driven by a computer and I wired a very cheap stereo speaker up and it worked fine so more speakers won't damage the sound card over time, will they?
I have been looking at the goldwood brand speakers and tweeters at partsexpress that are below $8 each and I was wondering if you could make a suggestion as to which ones to get? I think that one midrange and one tweeter in each cabinet would do it, but do I even need a tweeter?
Sorry for the long message and thank you for reading it

[sreten]

Hi,

I estimate your cabinets to be ~ 0.2cuft / 6L, you can add a bit
more to that (10% to 20%) if you stuff them with suitable material.

I am not aware of any computer sound card good at driving speakers.
They will drive 8 ohm headphones to typically around 100mW / 0.1W,
so speakers can be used directly but output will be very limited.

Choice of drivers for 100mW only or for a more normal amplifier
would be very different, the former requires efficiency emphasis.

Examples of likely the best sort of thing you can do is :
http://www.zaphaudio.com/ZBM4.html
http://www.rjbaudio.com/Microbe/microbe.html

But 100mW or so would be a complete waste of their capabilities.

The cheapest suitable "proper" speakers I can find seems :

http://www.geocities.com/cc00541/Scrappy.html

or perhaps the coax here :
http://www.apexjr.com/speakerstuff.html
Mounting is a bit tricky.

But if you going to use your soundcard .......

TBH I recommend a $100 pair of active speakers ....

/sreten.

[Andersonix]

You should also check for specials at Madisound. I wouldn't use anything Goldwood no matter how cheap, when for a few dollars more you could get something halfway respectable. Perhaps a single 3-4 inch Tang-Band or Hi-Vi (in which case you could check the 'full range' threads for more ideas)? Looks like the sides might not be flat enough for anything larger? Tell us more about the cabinets.

[sky12345]

I have decided to output the computer sound card signal to a stereo amplifier, which I will put inside the jukebox cabinet and that will allow me to hook normal speakers up. It seems that I will be able to get much better sound if I do it that way. Could you recommend speakers easier based on this? Is there a specific speaker and tweeter (if I need a tweeter) that would be good for this cabinet?
Thank you for the help!

[sky12345]

The sides are pretty curved, but there is room in the cabinets for a speaker that is up to 5 inches across.

[sreten]

Originally posted by sky12345
I have decided to output the computer sound card signal to a stereo amplifier, which I will put inside the jukebox cabinet and that will allow me to hook normal speakers up. It seems that I will be able to get much better sound if I do it that way. Could you recommend speakers easier based on this? Is there a specific speaker and tweeter (if I need a tweeter) that would be good for this cabinet?
Thank you for the help!

Hi,

All the designs in post #2 will work well in that cabinet.

/sreten.

[sky12345]

Sreten,
If I go with the vifa coax on the apex Jr website will I need to use a crossover in each of the cabinets or can I just wire the speakers to jacks on the back of each cabinet? If I need a crossover will the alesis 3 way that is listed on that same website work?
Thank you for the help!

[sreten]

Hi,

The above is the suggested crossover at apex jr and will
cost you morethan the drivers, where it comes from no idea.
The inductors are mH not uH.



The Alesis 3-way crossover is extremely good value for the bits, but
you have to be an inveterate fiddler with loudspeakers to make it
worth buying. The mid / treble level matching is going to be wrong
but there is a possibility the mid / treble c/o sections could work.

There is another thread on the Vifa Co-axial :

Help needed with Vifa A10CC-07

You can do worse than use the graphs in the above thread
and some tools to check out the above crossover :

http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spk...esigningXO.htm

I can tell you the crossover above has no baffle step at all.
That is OK in the above OB thread, but not for a small box.

You do need a c/o and level matching between the drivers.

Another option I should add is a sealed stuffed version of :

http://www.zaphaudio.com/ZMV5.html

That is the biggest bass driver you can fit.
You can do better but it will inevitably cost more.

/sreten.

[sky12345]

I am new to this so sorry I am asking so many questions, but what does 2.2uf, 3r, .35mh, etc mean in terms of parts? I thought they meant capicitor values, but I looked on the Apex jr site and all the values are in mfd.
I am not sure what a baffle step is, but do you know what I could add to the crossover that you posted from the previous thread for a baffle step?
Thank You!

[Drew Eckhardt]

Originally posted by sky12345
I am new to this so sorry I am asking so many questions, but what does 2.2uf, 3r, .35mh, etc mean in terms of parts? I thought they meant capicitor values, but I looked on the Apex jr site and all the values are in mfd.
I am not sure what a baffle step is, but do you know what I could add to the crossover that you posted from the previous thread for a baffle step?
Thank You!

The Farad is the unit of capacitance. u is a prefix for micro, as in 10^-6 or 1 millionth. 2.2uF = 2.2 * 10^-6 Farads. m is a prefix for mili, as in 10^-3 or 1 thousandth. 1 mfd = 1 milifarad = 1000uF.

The Henry is the unit of inductance. .35mH = .35 * 10^-3 Henries.

Restor values can be written with an R in place of the decimal point. 3R = 3.0 Ohms. Or a multiplier with K=1000 and M=1000000; 4K7 = 4700 Ohms.