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SUPPORT FORUMS FOR DECWARE SPEAKER PLANS >> Wicked One Support Forum >> Will 0.7" instead of 3/4" MDF make any difference?
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Message started by Icecake on 01/11/11 at 18:31:10

Title: Will 0.7" instead of 3/4" MDF make any difference?
Post by Icecake on 01/11/11 at 18:31:10

Hi guys,
I will be building my first WO but in my country there is no exact 3/4" (19mm) thick MDF panels.
What we have here is an exact 0.708" (18mm) MDF panels.

As the plan says that when using 3/4" (0.75") thick panels, the throat will be 1.25 x 1.25, and enlarging this opening will raise the
high frequency cutoff point.

So I guess if my panels is only 0.708" (18mm) instead of 0.75", the throat opening will be a bit bigger than 1.25 x 1.25.

Will it be any audible difference as I will use it primarily for my home theater subwoofer.

If that is a problem, I have an option to use a plywood combined with MDF as a single sheet which will be exactly 0.7677" thick (19.5mm).
This will make the throat slightly smaller than the original 1.25 x 1.25 plan, which I guess will lower the hi freq cutoff point.

Can anybody advice me which way to go?

Oh, another question is, do I have to put some absorbing materials like rockwools in each of the 'magnet chambers' ?

Thanks a lot for anybody who can help me with this.

I am expecting my DHM108 drivers and Dayton SA1000 amp to arrive anyday next week, so I am so excited to start building the box from now :)

Title: Re: Will 0.7" instead of 3/4" MDF make any difference?
Post by ZYGI on 01/12/11 at 12:34:20

Icecake,

The 18mm will be fine and the difference between the two at the port will be minimal at best. It might change the cutoff freq. by just a few hertz at most. Nothing to worry about there. If you wanted to stay exact to the 1.25" just but a gage block of 1.25" and cut the first piece longer to touch the gage block.

You don't need any absorptive material if you are using the DHM108's

ZYGI

Title: Re: Will 0.7" instead of 3/4" MDF make any difference?
Post by Icecake on 01/12/11 at 15:42:44

Hi Zigi,

Thanks a lot for your help.

Tomorrow I will go straight for the 18mm MDF boards then :)

Title: Re: Will 0.7" instead of 3/4" MDF make any difference?
Post by Bart_West-VL. on 01/12/11 at 19:24:43

Hi Icecake,

Where are you from?

Have fun and show us some pictures! 8-)

Title: Re: Will 0.7" instead of 3/4" MDF make any difference?
Post by Icecake on 01/13/11 at 01:42:24

Hi Bart,
I am from Indonesia.
I will try to take some pics about this :)

BTW, I will be using the Dayton SA1000 amplifier to drive the dual DHM108 drivers in the WO as recommended by Steve.