# "MORE" Speakers by Bob



## Bob in St. Louis (Jan 24, 2012)

Hey all!
Since there was interest in the speakers, I thought y'all might want to see some more.
I'll give a bit more explanation of what's going on with these than I did last time.
I hope you enjoy. 

The fella I'm building these for wanted an extra deep cavity for more sand. So this pair will be four layers of MDF (as opposed to three layers of Cherry on the other ones).









Here are the eight layers after routing;
(Do you guys consider this many circles in one picture...."Router Pornography"? hehe









The inner layers after routing out the cavities to hold the sand.









The middle two layers and the rear layers. Notice the sand spread out to make sure it's as dry as possible. 
Certainly don't want to seal up damp sand inside MDF! 









Here, I fill the cavity with sand and gently tap it with the rubber mallet to help it settle. Otherwise, after the speaker has been playing for a few weeks/months, the sand will settle and leave a big open void inside the top of the speaker.
I use a razor blade to "shovel" the sand off the glue surfaces to ensure a clean mating surface.









The unit sealed up with sand inside.









A few layers of fiberglass resin, to seal up the MDF and give the paint something to adhere to.









A few coats of primer









A final test fit of the drivers before the paint









Getting close









The final product (the black ones) sitting in between my daily units (the gray ones)
Note; The fella had his own drivers and installed them at home


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## LMT Onsrud (Onsrud) (Jan 9, 2012)

Bob in St. Louis said:


> Hey all!
> Since there was interest in the speakers, I thought y'all might want to see some more.
> I'll give a bit more explanation of what's going on with these than I did last time.
> I hope you enjoy.
> ...


Great Pics...Good job!

Fred


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## glycerine (Jan 19, 2012)

Very cool Bob!


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## Bob in St. Louis (Jan 24, 2012)

Thanks guys!

Wow Fred, that's one heckuva quote you've got there. ha ha

Bob


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## TwoSkies57 (Feb 23, 2009)

Looks like you've got the speaker thing down pat Bob. Excellent posts/how to's.. Not having much of a glue as to what goes into a good speaker. I find this quite interesting. Do you have anything along the lines of a smallish, get em dirty, get em dusty get em cheap for a shop type of speaker?


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## LMT Onsrud (Onsrud) (Jan 9, 2012)

Kinda wordy wasn't it! 

I'll try to cut back


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## Bob in St. Louis (Jan 24, 2012)

Hi Bill, thank you for the complements!
Over the years I've found that I've become "married" to the type of sound this particular audio company happens to have designed. At this point in time, they only make 10", 15" and 18" coaxial drivers. Not really what you call "small/quick/cheap/easy". haha

A pair of bare 10" or 15" drivers would set you back about $300 for their starter grade, of which I happen to use in my own workshop. In the picture below, they can be see hanging from the ceiling. They are still open in the back, but I've stretched some (acoustically transparent) fabric over the back to keep the dust out.
Note; In the picture, there are a couple drivers sitting on the workbench too.


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## Bob in St. Louis (Jan 24, 2012)

LMT Onsrud (Onsrud) said:


> Kinda wordy wasn't it!
> 
> I'll try to cut back


ha ha, no..Not the words, just that when you clicked [Reply With Quote], it reposts every picture I posted again. No worries.

Bob


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## Scottey66 (Feb 1, 2012)

Bob 
I didn't realise speakers had sand in them, wow good job


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## Bob in St. Louis (Jan 24, 2012)

Thanks Mike!

Yip, the sand helps to absorb vibrations in the speaker so the only thing moving is the cone. That helps to avoid the sound "smearing", so to speak.

Not sure if y'all wanted (yet) another thread about my speakers, but this is the project I'm working on currently. These are filled with a sand like material but the biggest difference is it's my first foray into veneering. Pretty neat, I'll be doing it again.

I've got 56 pictures of this build, and here's one.
The veneer is Pelin Burl:

Bob


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