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Kit showed-up today and looks great. Very well packaged and the hardware looks high quality.

If I got lazy, how bad an idea would it be to use this knock-down box kit from PE?
http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-7050
I'm thinking to cut out most of the dividers and use them as braces. It's still more volume than the shelf box plans but considerably less than the floor stand enclosure plans.
 

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Discussion Starter #23
Kit showed-up today and looks great. Very well packaged and the hardware looks high quality.

If I got lazy, how bad an idea would it be to use this knock-down box kit from PE?
http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-7050
I'm thinking to cut out most of the dividers and use them as braces. It's still more volume than the shelf box plans but considerably less than the floor stand enclosure plans.
That speaker will tare that box to pieces. You need a much heavier box.

They do make some .5 cubic foot boxes that can be used after you cut the center of the braces out. They ran the braces in them the wrong way causing a surface reflection issue.
 

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That's why I ask these questions. I'll just do it the old fashioned way. Home Depot has 3/4" Cabinet Grade Birch hardwood ply for $39/sheet. Would you recommend that over MDF or do you consider MDF to have better dampening characteristics? Two schools of thought on that.
 

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Discussion Starter #25
That's why I ask these questions. I'll just do it the old fashioned way. Home Depot has 3/4" Cabinet Grade Birch hardwood ply for $39/sheet. Would you recommend that over MDF or do you consider MDF to have better dampening characteristics? Two schools of thought on that.
I like the birch ply best for braces as structurally it is harder and stronger than MDF as a structural support.

But MDF is more inert and less resonant for panels. It is also easier to cut, easier to work with, cheaper, and easier to finish. It takes veneer well too.
 

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Discussion Starter #28
Any specs for the driver/tweeter/crossover? I had a brief look on your website but couldn't find any details.

Thanks :)
The woofer is listed on our web site: http://gr-research.com/m130woofer-1.aspx

Here is the frequency response curve.



It is around +/-1db.

Here it is on a 10db scale like everyone else posts.



And here is one showing the crossover point.



It is a smooth sounding speaker.

And the crossover uses only air core inductors, poly caps, and non-inductive wire wound resistors.
 

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I don't need more speakers and I don't need another project added to my list.
But, I want to build these Giant Killers!
I tuned in to this channel a little too late for the sale price, but I'm okay with that.
I'll place a call to order these tomorrow, after the Labor Day holiday.
Oh, I just noticed that you're only about 3 hours away. We're practically neighbors!
 

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Discussion Starter #30
I don't need more speakers and I don't need another project added to my list.
But, I want to build these Giant Killers!
I tuned in to this channel a little too late for the sale price, but I'm okay with that.
I'll place a call to order these tomorrow, after the Labor Day holiday.
Oh, I just noticed that you're only about 3 hours away. We're practically neighbors!
I have a set all boxed up, and you can call any time you want to order them.
 

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Coolness! Order placed. Nice talking to you. I thought I needed to wait until after the holiday was over.
Where were the cabinet plans, again? Sorry for the dumb question. You probably said it already.
 

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Do you have a link to the plans for the larger tower enclosure? May actually get around to building this now. Need to decide tower or shelf. :scratch:

Wait. Found the link in the thread. Thanks!
 

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I've constructed the enclosure using 1/2" Hardwood Ply instead of 3/4" MDF. You show a 3/8 internal radius on the midrange transducer mounting hole. With only 1/2" thick material, would that internal radius still be necessary? Also, how do you think the 1/2" hardwood vs the 3/4" MDF would affect the sound?
 

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Discussion Starter #36
I've constructed the enclosure using 1/2" Hardwood Ply instead of 3/4" MDF. You show a 3/8 internal radius on the midrange transducer mounting hole. With only 1/2" thick material, would that internal radius still be necessary? Also, how do you think the 1/2" hardwood vs the 3/4" MDF would affect the sound?
The hardwood will be very resonant compared to MDF. And being an even thinner material will make it worse. I'd add another layer using 1/2" MDF.

And if the inside edge doesn't have the radius then it will adversely effect the response. The edge diffraction will add a little bump around 1kHz.
 

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Adding another layer of MDF would be way too much of a pain. I may invest in some of your liner product to see if that helps. I will do the radius, at least enough to get rid for the inner edge. I'm very impressed with the sound just as they are now. They sound much bigger, and certainly much more expensive, than they are. I've photographed the construction process and will post a thread on that when I have time. I spent about $200 total on the pair and they sound better than most $1000 systems I've heard. Certainly better than any reasonably priced bookshelf speakers. They will get loud, but won't go rock concert loud. But gee, what do you expect from a speaker that size? Plenty of DB for most living rooms and certainly most apartments.
 

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Discussion Starter #38
Adding another layer of MDF would be way too much of a pain. I may invest in some of your liner product to see if that helps. I will do the radius, at least enough to get rid for the inner edge. I'm very impressed with the sound just as they are now. They sound much bigger, and certainly much more expensive, than they are. I've photographed the construction process and will post a thread on that when I have time. I spent about $200 total on the pair and they sound better than most $1000 systems I've heard. Certainly better than any reasonably priced bookshelf speakers. They will get loud, but won't go rock concert loud. But gee, what do you expect from a speaker that size? Plenty of DB for most living rooms and certainly most apartments.
Okay, cut some bracing using dowel rods to stiffen up the panels then line them with a sheet of No Rez and that will help a lot.

And I am glad you like them. They really are over achievers.
 

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I already have the stiffeners in the corners and the square stiffener spanning across the middle of the sides. That seemed to me to be enough to dampen the two, relatively small sides. Where else do you recommend adding the dowles? I assume you know I made the small box, not the large, floor standing one.
 

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Discussion Starter #40
I already have the stiffeners in the corners and the square stiffener spanning across the middle of the sides. That seemed to me to be enough to dampen the two, relatively small sides. Where else do you recommend adding the dowles? I assume you know I made the small box, not the large, floor standing one.
Corner braces are not really needed. The least resonant part of the box is in the corners.

Here is a pic of the prototype boxes.

 
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