Response of my new sonotube sub (1 Viewer)

[Scott Page]

Here is a graph of my new sonotube sub. Radio Shack SPL values are corrected. Initial level was set using a 1 KHz sine wave tone, set to 75db. These are SPL values from the sweet spot/listening position using sine waves. Response drops off below 11.5 hz. Sub was tuned to 15.8hz so I'm not sure why I'm getting so much output to 11.5hz. Room reinforcement? I haven't measured below 10Hz but I think I will now.
http://www.geocities.com/fool4nine/Sonosub3.jpg
I've got a big dip in the 25-31hz range that I hope I can smooth out by moving the sub around.
Sub is a 12 cubic foot, 24 inch diameter tube with an 8 inch port, approx 36" long. One Tempest on bottom, port on top. Driven by one channel of an Adcom 545 (150W into 4 ohms). Crossover from reciever is at 80Hz. Mains are Vandersteen 3A's.
I'll be doing more testing and try to have some sub pics soon. This is my first DIY sub and first attempt at testing/measuring so, comments welcome.
Scott
Well, I can't seem to get the link to work. But here are the values:
Level Set 1KHz 75 db
10hz 78db
11.5 84.7
12.5 85.5
16 84.5
20 81.5
25 83
26.6 74.5
31.5 77
40 84.5
50 80.5
63 84.5
80 75.5
100 75
[Edited last by Scott Page on November 16, 2001 at 01:29 PM]
[Edited last by Scott Page on November 16, 2001 at 01:42 PM]
[Edited last by Scott Page on November 16, 2001 at 01:44 PM]

 

[Brian Fellmeth]

Why not try a FR with the port plugged and see if the dip improves. If it does, then its not a room suckout. Also, I would wonder if your effective tune is lower then the theoretical 18.8 Hz.

 

[David Judah]

I couldn't get your page to come up.
I like your design though; it's similar to mine(Tempest on the bottom and 8" port on top--I drive mine with an Adcom as well).
Congrats on joining the DIY sub club.
DJ

 

[Andrew Pratt]

Well done scott...if you email me that image I can host it for you.
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