Grateful Dead Music Forum

Hey ya’ll.

This forum has brought me sound knowledge and a lot of good info over the years.

I just had an effect pedal I was demoing slide off the top of my twin head and into an original cone d120, leaving a 1.5cm (at most) ding into the paper. Upon further inspection half the ding did go through, it’s incredibly small.

Can someone with explicit wisdom on these old beauties help assuage my current freak out? These are my favorite speakers I’ve ever owned, original cone… would a cm size repair job by someone skilled make this tiny accident completely nullified sonically? Yikes! Help.

-Forrest

That’s pretty small. Can you hear any difference? I wouldn’t be surprised if you don’t. If it were me, I think I’d carefully straighten it out as much as I could and hit it with a small dab of rubber cement where it tore.

Bill, tgo

First off , super happy to hear someone with more experience considers that pretty small.

I really do think I heard a slight, very VERY slight difference after impact. I was cranked before and (seconds after).

Really nothing notable obviously. I just really want to know if applying rubber cement (or alternatives?) to the underside (backside, opposite facing the speaker’s cone) will be the best plan of action?

Thank you for taking time to help me and begin to explain away this current wave of panic!

-forrest

Fogle wrote: ↑Sun Mar 02, 2025 9:08 pm I really do think I heard a slight, very VERY slight difference after impact. I was cranked before and (seconds after).

Without the ability to A-B the speaker now against it before you dinged it, I'd guess the above is more likely due to confirmation bias than a truly audible difference.

I put a screwdriver through one of my speaker's cones once. My tech fixed it perfectly with rubber cement but as I recall he affixed a small, thin piece of cloth to the cone's rear facing side before applying the cement. In any event, for a speaker this valuable, you might want to entrust its repair to a pro.

Jon,

Thank you for the follow up and further detail. It is much appreciated. Took 36 hours to calm down, coming back here to follow up.

There’s not good way to tell now if it’s noticeably altered, never before did I try and A/B them before.

After doing so though, the undamaged speaker seems to be producing more volume and full frequency compared to the damaged. The undamaged speaker is the first (top speaker when placed vertical) speaker from the amp output wired in Parallel , the damaged one is the second (bottom when cab placed vertical).

After turning the volume past 6 the difference between the two speakers seems negligible.

Is this difference in speaker output at lower volume perhaps tied to the parallel wiring? I would be pretty shocked if a 1.5cm hole made this audible difference…
Thank you for sharing about the screwdriver incident, yikes! Makes me feel better.

Forrest

I’d swap the speakers to determine if the perceived difference is just a matter of placement rather than due to the little ding.

Bill, tgo

I had my K120 sitting on the floor close to pedal board in a crowded space, pulled the 1/4" plug from guitar and dropped it to ground and it bounced off pedals up into the speaker. Did it like 6 months ago and haven't had the heart to investigate further. I may try to rubber cement repair. I definitely notice a buzz sound.