What's Wrong With My 10-Year-Old Speakers?

January 10, 2008 9:02 AM

About 10 years ago, I bought a pair of Bose 301 Series 2 speakers. They've now been through a number of moves and they're sounding not-as-good. I'm not sure how to define the difference--they sound muddier, and less three-dimensional. I pulled off the front grill and didn't see any visible damage. How can I determine the cause, and then repair it?

(Subsidiary question: Some googling has led me to the possibility of surfoam rot but at least to my untrained eyes, there doesn't seem to be anything that looks rotty. Would this rot be immediately apparent with the grill off, or would I need to do something more to spot it?)

PS: I now know that Bose is not the audiophiles speaker of choice, but 10-years-ago-me didn't know that, so this is what I've got to work with...

posted by yankeefog to technology (11 comments total)

They've now been through a number of moves

They'll sound different in different locations. Also, your hearing ain't what it was 10 years ago.
posted by forallmankind at 9:13 AM on January 10, 2008

I don't know those exact speakers, but most have rubber as a key component that allows flexibility of movement for the coil.

Over time, most plastics degrade due to various things in the air. Here in LA, it's fairly fast.

As the rubber degrades, the flexibility degrades, reducing the travel ability of the actual speaker coil. The rubber won't look a lot different, but a slight change in flexibility *could* create a slight change in the audio quality.

This could be your problem. At work, we deal with lots of AV stuff long term where rubber belts, wheels, and seals need to be replaced regularly.

The bad news is that you are unlikely to be able to fix the rubber since it's usually part of the speaker cone itself.

On a side note, Bose makes good speakers, but they are a bit overpriced (due to all the marketing dollars they spend). But with audio, it's all subjective to the listener. If you decide to get new speakers, ignore the salesman and just listen for yourself. Each person's hearing frequency response is different and what "sounds good" is a subjective decision, so what other people think doesn't count for sh*t.
posted by Argyle at 9:26 AM on January 10, 2008

Oops, where I said "plastics" in the second sentence, I meant "rubber".
posted by Argyle at 9:27 AM on January 10, 2008

Speakers definitely mellow out. In guitar amps this is often a good thing. In HiFi, not so much. Magnets get not-so-magnetty, plastics age, foam becomes brittle, speaker cones may lose a bit of stiffness.

Inexpensive (as opposed to cheap) speakers are really really good now. I'd go buy some.
posted by unSane at 9:28 AM on January 10, 2008

They're probably not phased correctly. Make sure you have all of the + and - wires connected properly.
posted by wfc123 at 9:51 AM on January 10, 2008

The foam or rubber surrounds may look okay, but you might want to do a touch test. A few years ago I was checking-over my JBL L100t's (because they, too, really weren't sounding good anymore) I noticed that the foam surrounds on the bass drivers looked...odd. I gently touched the foam and my finger went straight through and the foam disintegrated!
The foam was shot.
I checked-out the re-foam kits and really wasn't sold. I had both drivers replaced with factory units. Now they rock as sweet as before.
posted by Thorzdad at 10:00 AM on January 10, 2008

Seconding Thorzdad. I've had these speakers before, just take the square grille off (the woofer one) and poke the edge of the speaker cone (the rubber that bows out a bit). See if it cracks when you pinch it or breaks for some other reason. You should be able to play with it as you would a bike tire. Pinch and poke! The tweeters should be fine.
posted by rhizome at 10:26 AM on January 10, 2008

Phase reverse is easiest to check, so I'd eliminate it first... It's also possible that some fill or matting inside the cabinet has fallen off and is now blocking a reflex port or touching one of the cones and inhibiting it. I'd pull the driver and take a look inside. N'thing everybody else on the possibility of surround rot - Again, I'd just refoam them myself, but I'm the crafty type and enjoy that ship-in-a-bottle type stuff.
posted by Orb2069 at 2:44 PM on January 10, 2008

I've checked the + and - wires--but they are definitely connected properly, so that's not the issue.

Thozdad and Rhizome, I just took your advice and poked and pulled the edge of the speaker cone and they seems to respond just fine. However, that leaves open the possibilty that Argyle raised, which is that they have degraded enough to hamper the sound, but not enough to be detectable by my untrained senses. (Also, I should note that these speakers were in LA for 5 of the 10 years I've owned them, so air pollution undoubtedly had an impact.)

Orb2069, I'll look inside the cabinet and see if something is blocked. Good idea.

unSane, you're probably right that the best thing is just to buy new ones. But even if I do, ideally I'd get the old ones working as well as possible before reselling them, so all these suggestions are very helpful.
posted by yankeefog at 8:00 AM on January 11, 2008

Oh, and also:

Thanks, everybody!
posted by yankeefog at 8:00 AM on January 11, 2008

Don't just judge the phase by the wires, judge it by ear as well. You should be able to tell pretty easily when comparing directly (side-by-side, so to speak). You are probably right though :P

It is remotely possible that a wire has dropped off of one of the drivers.

And for the record, re-foaming speaker drivers is really quite easy, though a little time consuming.
posted by Chuckles at 5:22 PM on January 11, 2008