Mod journal for sl1364 5.5 " Midwoofer

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Welcome to my modification journal for the unit SL1364. Pardon my very crude measurement setup but it seems to be fairly capable of at least distinguishing changes made amongst the group. I'm fairly thrilled that a speaker sitting on the floor wrapped up in two towels managed to get such consistent measurements.

With very near field measurements (5mm or less) I was able to determine that the dust cap was the main offender for the breakup that appears at about 4500 hz. I'll repeat these measurements and save the results this time if there is interest.

I have since tried making tape with fair results, clear plastic tape on the dust cap with lesser results, applying latex over the top of the plastic tape with poor results. I will likely play with the masking tape more and report back if I get results that are comparable to that of B- grade balsa.

The balsa is simply affixed with a small strip of masking tape for the moment. I will compare a few diffrent glues including titebond, superglue and a 2 part epoxy. If anyone has any other waterproof suggestions I'd appreciate it.

With whatever glue system works best I'll try an acrylic coating. Does anyone have a list of good paper treatment materials?

Zaph's measurements sure are 1000% better :)

FirstModSets-1.jpg


SDC10974.jpg


SDC10973.jpg


SDC10972.jpg


SDC10971.jpg


Mind the tangled mess :cannotbe:
 
For the full size version of the above graph go here:
http://i8.photobucket.com/albums/a44/OlogyAudio/FirstModSets.jpg

I went back and revised the application technique for the clear plastic packing tape and included CSD plots this time through. I also added reinforcement to each side of the actual cone body with two extra segments of balsa/masking tape composite with a slight improvement.

These measurements are also taken at 12" in order to get a more accurate representation of what is happening at the breakup. This measurement distance seems to introduce an artifact at 1.5khz. I wouldn't pay much attention to the CSD under 2khz accordingly since this is a mounting issue.

See the full version here:
http://i8.photobucket.com/albums/a44/OlogyAudio/clearpacking5stripbalsab.jpg
clearpacking5stripbalsab-1.jpg


I'll go back and check off axis for the balsa modification in a minute but don't hold your breath, it is just wrapped in a towel after all and it might not turn out too well.
 
I just saw a thread using rubber cement with success so I'll try applying a thicker coating on in a bit, I only applied the thinnest possible coating and it made things slightly worse so I ruled it out.

I'm starting to get a hang of ARTA at least. For the full picture go here:
http://i8.photobucket.com/albums/a44/OlogyAudio/Distortionbminusgradeplastic.gif
Distortionbminusgradeplastic-1.gif


Speaker Workshop is what I had always been using but it just wasn't cooperating with my laptop. As it is I have a ton of noise going through the speaker output when my laptop is plugged in, has anyone heard of this? Bad ground in the adapter? The surge protector indicates a good ground in the building. :confused:
 
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