Building secound sono sub need some info.. (1 Viewer)

[Joe Tilley]

Well Ive decided I wont to build a secound sono sub just for fun pretty much but Id like to try and get some more bass if possable.Right now I have a single 16"by44" sono with a 15" dayton DVC sealed,and a PE 250watt plate amp.What Id like to do is build another with the same amp if possable and same dimater tube but I wont to make it ported tuned to around 16hz and use the new dayton Titanic MKII 1202 sub.My question's are what lingth will I need to make the tube,what size ports will I need to use & how many,and would it be possable to out perform my current sealed 15" with something like this.

Im pretty happy with what I have now but Id like to get just a little lower if I can,also I should mention I will probley build another matching one to this later on but I wont to see what happens with a single one first.

Thanks for any help...

 

[Dustin B]

Well the 15" DVC has a Vd of 2.44L and the 12" Titanic MKII has a Vd of 1.9L. So the 15" has a desided displacement advantage.

A 16x44 tube will give you about 140L to work with. Lets say you could net 132L after the driver and port are accounted for. A 4" flared port would need to be 25.5" long to tune to 16hz. The rule of thumb is a port should not be more than 5 times it's diameter in length. An 18hz tune would require a 19.5" four inch flared port.

If you can go to 18" dia tube and make it taller, I'd reccommend keeping the 15" Dayton and going tall enough to get a net volume over 200L and use dual 4" ports or a 6" port to tune to 16-18hz.

 

[Joe Tilley]

Thanks for the reply Dustin,as far as goging to a larger dimater tube thers no way I can,so anything over 16" is out but as far as highth thats not so much a problem. I was thinking about going with a 12" just hopeing to get a more controled sound for music.My current sub sounds awsom with movies but any kind of music with a fast bass it just dont sound right.Im more movies mabey 80 20 so I wont to have it sound good for that but I still wont fast tight bass for my music I dont know am I going the wrong direction? What if I built a smaller system of some sort more for spl not depth do you think this might help.

 

[Dustin B]

Driver diameter has nothing to do with how tight it will sound. It depends on the motor strength and the Q of your box. A 15" dvc has plenty of motor strength so I would guess the problem is your box Q is too high. I think your up around 0.7 and would like to be under 0.6.

Using 16" tube I don't think you could get large enough with the 15" driver to get the Q down that low. Sealed, I think you could. I'm not confident in my Q calculating skills yet, so hopefully someone who is will chime in with what is required for both drivers to get a sub 0.6Q.

 

[Joe Tilley]

Ok this is another thing Im starting to try and understand ( the differnt mesurements of a speaker) what is the Q exactly,and if I need to bring it down,if I understand you right how will I need to go about it?