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speaker refurbish

wayne klyne

wayne klyne

New Member
Iam doing a DIY fix-up on a pair of ULTRALINER 100-O/W ,extra blocks ,silicone seal and new acoustical sound dampening ,It is a front ported speaker should I just damp the sides like I read or the back or both ,also what kind of damping should I use , seal the inside with paint making it air tight ? any other ideas any body can help me with sure would be appreciated.
 
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Greetings;

I have no idea of the construction of these.. just have seen pics now and then. No need to paint insides.. just seal corners. Dampening is a matter of testing and how much you need. i.e. big open area? no fill might be too boomy'. I would invest in some gaskets home made from cork or thin weather strip etc. for the drivers as that will cut out leaks and present more to the port and cut potential driver buzzing on the face mounts, too.

How much fill? and what to use? Walmart quilt fill is good and inexpensive. Loose fill? I don't like because it's loose but good to pack book shelf small boxes. To me it's really just trial and error and listening. I'd try at least half way from center down the walls and bottom of box stapled. might need more above woofer if too resonant. then there are port tuning tube lengths, too.
 
I have a speaker refurbish project going with some JBL 4412 Control Monitors. They smell musty and I want to replace the fiberglass insulation. Can I just use regular bat insulation with no Kraft backing like the sell at the big box store? Thanks
 
For health reasons, no don't use home insulation. My recommendation of using quilting batt was recommended by others here at ak. 1" or you easily double staple over another layer. I used a simple light weight staple gun with smaller than 1/4" staples to lay up easy and the batt cuts easy and i fold the corners over, too. you'll spend more time taking out the drivers than applying the batt.
 
I would beef up the wires inside. People kept talking about how important the speaker cable, that you need big cables. But inside the speaker, I've seen small wires used. I am talking about at least mid to high end speakers. I have a pair of Kef Uni-Q floor standing with dual 6" woofers each. They costed me $1100 for the pair. I opened it up, the wires are like 16 or 18 gauge only. I looked at the pcb trace on the crossover pcb, they are quite narrow. I doubled up the wires in one speaker, putting extra jumper wires to beef up the trace on the crossover pcb. I did not add any insulating material nor seal anything. I just put everything back. I compare one speaker to the other, I swear I could hear a little better transparency. Of cause this is not blind test and I am sure psychosomatic came into play. But that's my impression. I modified the second one, they sound the same since.

Speaker wires are very important, I did experiment before, but lately while I was bringing up my own design, I did FFT spectrum plot of my amp, I saw 6dB increase of 3rd harmonics just because of 7" of 14 gauge wire from the output of the amp to the load. I was shock and stunned by the result. This is from instrument, not by ears that is not reliable and subjective. I double the wire and I lower the distortion back down a lot. 7" or 14 gauge wire!!!!

This hold true inside power amp also. I opened up my Nakamichi PA-7 power amp that was designed by Nelson Pass, it retailed for $1800 to $2000 when it was new. The speaker wires are 18 gauge!!! How stupid is that!!!?

Do that first and see what happens.
 
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