DIY subwoofer with TRIO 15" woofer

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
Inductor

Inductor

Member
Joined 2006
15" Kenwood Trio woofer/sub alignment

Good, you got all the T/S parameters.

They give you an ordinary project in the top or your spec sheet, for the 15" Kenwood Trio with a reflex enclosure of 90 L.

You said you would be fine with 120 L on post #9.
marekocska said:
I don't know, if they used to sell DIY speakers.

Here in Budapest there's a shop where they measure speakers for 10 USD. I'll get them there. 500l cabinet is huge!!! I'll try it in a aproximatelly 120l box without bottom, because I have no more room...or maybe a Lukasz Fikus (Lampizator.eu) design, a 50cm x 50cm x 50cm box without back (folded open baffle?)
Click to expand...

The best solution for this driver is a reflex enclosure:

Enclosure alignment: 114 L (net) and tuned to 30 Hz.
Port Diameter: 11.8 cm (surface of port: 109.36 cm2)
Port Length: 23.64 cm

Above I'm giving the measurements for a calibrated port.
Note: (You will have to do that by ear) port in size (internal diameter x internal length). After that you can decide if going with a rectangular or tubular port. Always have in mind that to the net dimensions/volume you need to add driver and space/volume of the port.

Now let's recheck above internal dimensions of the enclosure adding port volume (tube/ABS, other) and driver:
114.2 L
15 inch - 4.0 liters
tube/port volume - 2.6 liters
Total internal volume: 120.8 L
(That's the same you had in view for the max. volume/footprint.)

You can play with port size and volume (a rectangular port made of 19 Ply Marine Plywood would have a bigger volume inside the speaker than a plastic 2.5 mm thickness tube.

The type of port/tube (diameter dimensions) you choose, let's say a 10 cm internal diameter. You then have to recalculate the port and internal dimensions of the enclosure (the same speaker alignment):

Practical dimensions:
Enclosure internal volume*: 119.5 L (net), tuning: 30 Hz.
Port Diameter: 10.0 cm (surface of port: 78.54 cm2, for a rectangular port)
Port Length: 15.83 cm
* (15 inch - 4.0 liters, tube/port volume - 1.2 liters, already included)

Note: this is exactly the same alignment as the one above, but the area of the port is smaller. After you get the appropriate exact internal volume, that you want (expected) and the size or diameter of the port (and the material, plastic/ply), it's better to recalculate the alignment for the exact frequency, something you can do by ear, after the speaker is built. :nod:

Links:
Tannoy Monitor Gold 15" - 1968 Vintage Dual Concentric Speakers - YouTube
Diana Krall "Live in Rio" HD - YouTube
Diana Krall singing in Portuguese :)
 

Attachments

  • KENWOOD TRIO, VB = 114.2 L, FB = 29.7 Hz, 96.3 dB2.83Vm.jpg
    KENWOOD TRIO, VB = 114.2 L, FB = 29.7 Hz, 96.3 dB2.83Vm.jpg
    123.2 KB · Views: 103
Inductor

Inductor

Member
Joined 2006
marekocska said:
you're welcome! Feel free to post it anywhere in the internet!!!
Click to expand...
And the price was right. They included one alignment in the spec sheet. Did you ask for one, or how did they come up with it?! :)

marekocska said:
I don't know, if they used to sell DIY speakers.

Here in Budapest there's a shop where they measure speakers for 10 USD. I'll get them there. 500l cabinet is huge!!! I'll try it in a aproximatelly 120l box without bottom, because I have no more room...or maybe a Lukasz Fikus (Lampizator.eu) design, a 50cm x 50cm x 50cm box without back (folded open baffle?)
Click to expand...

It says here that this driver is not very good for that purpose (OB), in LF of course for that application, or "totally discouraged". :)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom