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Discussion Starter #42 (Edited)
Added grill mounting hardware and attached grill assembly tonight.

Now to start playing with REW and add subwoofer EQ capability (likely MiniDSP) as I performed a frequency sweep with the new amp and confirmed again my room's major peak around 40 Hz.

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Discussion Starter #43
I picked up a MiniDSP 2x4 Box (w/2 Way Advanced 21 plug-in) as well as a Behringer UCA222 usb sound card (to provide line in/out in support of REW) for my laptop.

In conjunction with a Radio Shack analog SPL meter I already had, I have effectively tamed the volcanic peak at 40 Hz. The integration between REW and MiniDSP is a cinch.

I am still tinkering with house curves and such but here is the latest before and after response of the subwoofer.

before_after_eq.jpg
 

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nice project! just one question, is the back cover with a hole will be left as it is? if so then there would be more bass reflex exiting the back cover than the front port? please advice me on this part. thanks!
 

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Yep, me too.

I also wanted to say to the original thread starter that is beautiful work. Must feel good to be finishing such a long project.
 

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Discussion Starter #48
Yep, me too.

I also wanted to say to the original thread starter that is beautiful work. Must feel good to be finishing such a long project.
Thanks. Yes, always good to get a project behind you, especially one so long in the making.

I enjoyed the sub project but don't know that I'll need to do it again. I've moved on to a kitchen renovation that is keeping me busy these days.
 

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Very nice Build !!

I just have one question, could you have used the hole width of the box for the port ? Like some of the Martysubs over at AVS ??

thanks.
 

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Discussion Starter #50
Very nice Build !!

I just have one question, could you have used the hole width of the box for the port ? Like some of the Martysubs over at AVS ??

thanks.
Sure, but realize that the port dimensions directly affect the tuning of the box as well as the maximum port velocity.

For instance, if I left the 2.5" port height the same but widened to the walls of the box, the port length would need to increase to maintain the same tuning due to the increased volume. That may have then caused the port to mechanically crash into the plate amp and the box design wouldn't work. Alternatively, if I reduced the length to still fit within the box, the tuning would change. Decreasing the height of the port to maintain the same volume/length/tuning, the surface area of the port increases which could negatively affect potential chuffing.

In other words, all the variables of external box dimensions, internal volume, max port velocity, tuning frequency, and cosmetics must all be considered to provide a design that works and meets your requirements.

Simple, right? :)

I played with WinISD alot to determine the effect port dimensions, internal volume, and power have on response, port velocity, and excursion. I then used Sketchup to see what was mechanically practical and still meet my WAF requirements.
 

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Well dboff01, I've saved your build in favourites because as coincidence would have it, I'm planning on building a very similar sub with a Dayton UM 15. I must have missed it but what is the net internal volume of your box and tuning freq. please.?? Mine enclosure will be 174 Litres tuned to 16 Hz.
 

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Discussion Starter #52
Well dboff01, I've saved your build in favourites because as coincidence would have it, I'm planning on building a very similar sub with a Dayton UM 15. I must have missed it but what is the net internal volume of your box and tuning freq. please.?? Mine enclosure will be 174 Litres tuned to 16 Hz.
From the 1st post in the thread, internal volume is 5.1 cf (144 litres) tuned to 20 Hz.
 

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I know it has been a couple of months since the last post here, but I just wanted to say thanks for the thread and for the insights you gave. I'm currently building two 12" ported subs of a similar design as yours, and your thread has been real helpful. Thanks again, and great job on the build. --Mario
 

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Discussion Starter #54
I know it has been a couple of months since the last post here, but I just wanted to say thanks for the thread and for the insights you gave. I'm currently building two 12" ported subs of a similar design as yours, and your thread has been real helpful. Thanks again, and great job on the build. --Mario
No problem, it was a fun project and I'm glad I could share.

If not for the excellent threads here that proceeded my build, I never would've been able to do something like this.
 
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