8mm Forum: check your speakers!

This is topic check your speakers! in forum General Yak at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=8;t=001023

Posted by Chip Gelmini (Member # 44) on October 01, 2008, 09:35 AM:

DRY ROT IN SPEAKERS

For some time now, I had been hearing distortion during loud bass response during movie play. It seemed as if I noticed in the theater first. It was coming from the left channel. But later on, I also realized I was hearing it from the left channel inside the control room too.

Since some of my equipment is rather new, that’s exactly where I started to check this to begin with. All the tests I tried failed. I swapped out equipment; swapped cables. Nothing worked and the problem continued.

I also even thought this was normal, because for many years I had run only super 8 analog in this cinema. And it seemed as if this problem began just after I started running DVD with stronger digital sound.

Boy, was I ever wrong.

I finally built up the courage to remove the speaker grills and check the cones. And imagine my shock and horror when I found that, around the outside diameter of the woofers, the foam paper cone was breaking apart. Basically, the cone had begun to disintegrate. And I’m not the type to blow speakers by pushing too much sound through them all the time.

I opted to replace the cones, midranges, and tweeters in the screen pair of speakers, because I paid a lot of money back in 1988 for them. The repair estimate was one half the original purchase price.

I considered buying a different pair of speakers, but for the price budget I had it just did not allow for something just as good as what had worn out.

In this forum we share much information about running movies and such. I am posting this letter because if you have been running through a sound system for the past 12 years or longer and you have never checked your speakers, now is a good time to do so. Although you might not be having any problems as you might think, I suspect these have been wearing out for the past couple of years, and it took for them to get really bad before I noticed.

I’m picking up the repaired speakers in a couple of days. Next week I shall re-install to the screen and test. I’ll follow up here with the results below.

So please, everyone: Take a moment and check your audio equipment. You might be surprised as I was, but it can’t do any harm. Take care of it, and likewise it only gets better.

(EDIT: In another post here, I recently wrote about a defect Little Mermaid disc that has a sound problem. As described in the Mermaid post that is a different problem as the channels are reversed. This post about dry rot is very DIFFERENT)

~ CG ~

Posted by Claus Harding (Member # 702) on October 01, 2008, 10:02 AM:

Chip,

Good post on something that catches up to older speakers. They do wear out this way. In hi-fi circles this is a regular subject, as people have the surrounds on their older speaker drivers re-coned or re-done for this reason. My 1980es JBL 350s finally gave in to this as well (the woofer surrounds came apart.)
The rubber and paper surrounding the drivers simply cracks in places when it gets too old. Rattles and poor frequency response results.

Claus.

UBB.classic^TM 6.3.1.2