Home Theater Forum and Systems banner

1 - 17 of 17 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
I will be building a downfiring ported Tempest X2 sub for my brother's bedroom and would appreciate suggestions/help on the design.

He has told me that he wants a downfiring sub which looks similar to his Yamaha YST-SW800. He wants the dimensions of the main enclosure to be around 600mmx600mmx600mm but he is willing to go to 700mmx700mmx700mm if it is worth it.

Just a quick sketch of what he wants (next to his old sub):

Sub.jpg

I have been doing some modeling with WinISD Pro but would you be able to give suggestions on the port design. He is really keen on a round port (or multiple ports) and I am willing to do bends but if it causes too many problems please give your ideas on a slot port. On slot ports, is it worth staying to a 5:1 ratio or less and would it make any difference if it was facing the wall (the sub will be diagonally in a corner so there is heaps of space behind it)? We were aiming at around a 16-18hz tune.

He would like a Yamaha P2500S amp which I believe should have plenty of power (1300W in 4 ohms bridged) can somone confirm this? or recommend another amp if it wont work. We will also need a high pass filter so could someone recommend one? We would probably set it at 19hz but feel free to adjust this to what will best suit the sub.

Ok thats a lot of questions :yikes: thanks in advance for help,

Sam T
 

·
Registered
Joined
·
17 Posts
Discussion Starter #9
Thanks for that, I came up with 4.715 ft^3 as the final volume, but do you know if there is a google sketchup model for the tempest so that I can work out the internal bracing more accurately. Also, what thickness MDF would you reccommend for various parts of the box?
 

·
Premium Member
Joined
·
19,397 Posts
Recheck your numbers, that seems small for some reason. If you do have 4.7 cu.ft. net volume then a 6" diameter port would be 36" long or you could use two 4" ports each being 33" long.

Building material should be 3/4".

The cabinet legs should be 4" high.

Contact members Moonfly and gperkins_1973, they might have a SketchUp file for the Tempest-X.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #11
Are the air velocity values in WinISD a total across the ports or per port. e.g if it says 25m/s but I have two ports will it be 25m/s in each port or 12.5m/s?

Thanks,

Sam T
 

·
Registered
Joined
·
17 Posts
Discussion Starter #14
Ah thanks for that :T, I have tried many combinations of multiple ports only to get a high port velocity. Using Flare-it it shows plenty of headroom before chuffing occurs with a flared port.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #15
Ok so this is what I have in WinISD:

SPL.JPG

The ports are 3.93" which is 100mm.

AirVelocity.JPG

Excursion.JPG

And Flare-it recommends a minimum flare radius of 36mm so we will probably go for around 40mm.

Flare-it.JPG

Does everything look OK?

Also, should I post in the amp section about the amp and highpass?
What high cut/low pass settings would you recommend?


Thanks for all the help,

Sam
 

·
Registered
Joined
·
17 Posts
Discussion Starter #16
If we went with a ep2000 amp instead of the yamaha one (saves $300 in Australia), and used a reckhorn b-2, what should we use for a high cut (lowpass filter) should we use? Also, do you use the LFE outputs or preamp out?
 
1 - 17 of 17 Posts
Top