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Alembic products => Alembic Basses & Guitars => Topic started by: gtrguy on October 14, 2005, 09:47:54 AM

Title: Nd advice building practice speaker cab
Post by: gtrguy on October 14, 2005, 09:47:54 AM

Hi folks,
 
I want to build a speaker cab around a 15 inch EV speaker I own. I pulled it from a Lab Series L9 amp (vintage BB King stuff) after plugging it into the SWR to make sure it sounded good (it did) I will be using it for practice, so it needs to fit in the trunk of a Mustang (cab should not be over 14 inchs wide. I want a small size and will be using it with a SWR 350 head just for practice.  
 
I don't know if I need a closed cab with a port, or what kind of port. Can anyone help me with some advice?
 
Thanks,
Dave

Title: Nd advice building practice speaker cab
Post by: phys49 on October 14, 2005, 11:01:32 AM

If you can find the Thiele-Small parameters for the speaker, you can build a box that will give the best sound for the smallest volume.
Without them it is pretty much a guess but a box 12 inches deep by 18 inches wide and 24 inches high out of 3/4 plywood or particleboard will probably give a decent sound.
As for the port, use a slot port similar to SWR construction all the way across the bottom of the front baffle. You may have to experiment with the height of the port. Start with 1/2 inch then go to 3/4 or 1.0 inch if there is too much whistling.
Do not expect maximum performance using these dimensions. They are just a guess based on my experience with EV 15 inch speakers.
best of luck,
Perry

Title: Nd advice building practice speaker cab
Post by: bassman10096 on October 14, 2005, 05:49:35 PM

There's a very good free download cab design calculator at http://www.linearteam.dk/default.aspx?pageid=teaminfo (http://www.linearteam.dk/default.aspx?pageid=teaminfo).  I've used the calculator successfully for several years and 4 or 5 cabs.  It's very easy to use, but best of all, the calc has T-S parameters for a couple hundred drivers that are listed by make and model.  You don't need to enter or even know the T-S data.  And the calc can adjust for any size or dimensions you tell it.  Saves a lot of trial and accident.