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Discussion Starter #1
Hello,
I am building a pair of the Dayton/PE Dr. K's MTMs.

Question #1
I'm debating whether to go with a 1.7 cu. ft. ported tower, or the TL enclosure originally designed for the Seas Thor. I've read that somebody has done this before, dubbed the "Dr. Thor" but I can't seem to find much info on the pros and cons between the two.

Question #2
Unless someone out there knows how the Dr. Thors sound, I'll probably play it safe and go for the 1.7 cu. ft. enclosure mentioned in the original Dr. K's writeup. Now I need to know what port length should be used if I opt for a 4" dia. port.
In the writeup, the designer, Darren Kuzma says:

A larger “extended bass” version of the tower would be approximately 1.7 cu. ft., tuned to 35 Hz via a 3″ x 6-1/2″ port. Again using 3/4″ MDF, this cabinet would measure roughly 9″ wide, 40″ tall, and 12″ deep. Note for these larger cabinets, a 3″ diameter port is preferred, and a 4″ port is an option if you are going to be running the speakers at high power.
I built two "500w" monoblocks from a kit that uses ICE Power boards, so I'm assuming this would be considered "high power." So I bought a 4" dia. port, however he doesn't say how long the port should be if you opt for the 4".

Any help is greatly appreciated!

Thanks!
 

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It would depend on the correction factor for flares/no flares, but assuming flared on both ends, it would be around 12.8 inches.
 

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Discussion Starter #3
The port is (for now, unless you think I should change it) is only flared on the outside.

So, if I use a 3" port, it should be 6 1/2" long. If I use a bigger 4" port, it has to be twice as long? Sorry, I'm obviously a Noob but, for some reason I assumed the larger diameter port would be shorter.

Should I just go with the 3" x 6 1/2" then? The cabinet will only be 10 1/2" deep internally so, if I went with the 4 x 12.8" I'd have to buy some elbows and another 12" x 4" tube to make it work.

What do you think?

Thanks so much!!!!!!
 

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The design you mentioned uses the old RS28 tweeters which were discontinued a few years ago. Unfortunately the new RST versions are not the same and can't be used in that design without reworking the crossover.
 

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Discussion Starter #7
Oh no! Okay, does anyone have information on how to rework the crossover to make this work with the new tweeter?
Thanks!
 

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Discussion Starter #9
It would depend on the correction factor for flares/no flares, but assuming flared on both ends, it would be around 12.8 inches.
Thanks so much for your reply! So I decided to return the 4" and go with the 3" diameter.

New question: I ordered inside and outside flares (precision port) and the two flares by themselves measure nearly 5.9" in length. So would I only cut a 0.6" center section to reach the 6.5" recommended in the original post?
It looks kind of silly, basically just two flares back-to-back.

Thoughts?

Thanks again!
 

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I wouldn't bother cutting .6" of port length. The difference will be almost nothing. Not worth the risk of messing up the plastic.
 
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