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Q12 12" Sub

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Tony Wilkes View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tony Wilkes Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2009 at 8:09pm
Port is on the back mainly to allow me to check Magnet temps, also has the benefits of smaller baffle, less port noise and it has to help cooling.

Tony
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Tony Wilkes View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tony Wilkes Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2009 at 8:07pm
Originally posted by Jake_Fielder Jake_Fielder wrote:

That looks really good, how did u model the port being close to the driver? did you just add an estimated length to the port??


No I use bassbox pro to get an approx length then build and measure the exact frequency. On this design I bring the port to within 40mm of the magnet assembly. This added air resistance actually drops the port frequency by a couple of hz. 
On this box the port frequency is 45hz.

Tony
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jake_Fielder Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2009 at 7:53pm
That looks really good, how did u model the port being close to the driver? did you just add an estimated length to the port??
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Unknown Enemy Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2009 at 7:48pm
Looking good there Tony.


I have still yet to house my 12" subs I bought from you. lol. I started to build a double cab. Made it 110 litres and got 124db max spl from sims.

Saw this tapped horn stuff, put the info in there and now Im getting 125db at 39hz just from the one driver at 99 litres I think it was. Has a bit of a dip between 40 and 100 hz but some eq could help that out i hope.

Have the stuff ready on HR but have no idea how to put this data in to a cab. I downloaded google skecth but have no idea where to start.



Anyway, just out of interest, why is the port on the back instead of the front? To keep the cab more compact in size???
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Tony Wilkes View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tony Wilkes Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2009 at 5:22pm
Nowadays I get much more pleasure taking small systems to venue's and watching reactions when the "toys" perform perfectly adequately for the job.

I have built this little jobby just to test the alignment that I will use in a twin version.

I have  been a bit aggressive with the tuning and have gone for a couple of db lift  at the bottom end instead of the flat response that I normally go for.

It is still -3db at 42 hz and -6 at 38 hz not bad for a 12" in a 40l box. efficiency is on the low side though and I should get a max'm output of about 119db continuous. I am hoping output for the twin model will be close to the theoretical 125db which should be ample for most pubs/small clubs.









Tony









Edited by Tony Wilkes - 18 March 2012 at 12:49pm
www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE)
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