Boston Acoustics 381 to Boston Acoustics CR9 - woofer replacement

[youdiejoe]

I wanted to share something I stumbled across accidentally while looking at local Craigslist listings. Someone was selling a set of four Boston Acoustic 381 in-wall speakers and normally I wouldn't notice in-wall speakers but in the photos one of speakers had the grill off and I thought that the size and layout looked very familiar. I searched for the specs on the 381 and it turns out they have the same 8" woofer and 1" tweeter sizes as the CR9. A bit of backstory, I have several pairs of CR9 speakers, the last set I acquired had a shredded woofer in one of the cabinets, so I keep my eyes open for CR9 for sale which are fewer to non existent these days.

I purchased the set of four 381 and hoped that the fit would work, and they did! Not just the same size but an exact matching 1:1 fit. The only difference I noticed, once I unscrewed the shielding off of the woofer from the CR9 cabinet, it has a 2nd magnet glued to back of the speaker where the 381 does not. I would attribute this to saving space for an in-wall speaker. The shield from the CR9 woofer fit perfectly on the 381 woofer that I transferred and it has the exact same mounting screws and gasket. The tweeter is the same as well (I didn't need to transfer that) minus the large heat fin that are on the CR9 tweeters, but I'm sure those can transfer as well.

Hope this helps someone looking for CR9 parts replacement.

PS in kind, I would imagine that the others in this in-wall series, the 351 and 361 would also hold replacement parts for CR6 and CR8 speakers.

 

[swechsler]

That second magnet is a "bucking" magnet, it was put there to counteract the magnetic field from the speakers to prevent them from interfering with CRT TVs. It should not affect the performance of the speaker at all. Since an in-wall speaker probably wouldn't be close enough to a TV to affect it, there's no reason to go through the extra expense of adding the bucking magnet. And since CRTs are becoming extinct, so are bucking magnets.

 

[youdiejoe]

That second magnet is a "bucking" magnet, it was put there to counteract the magnetic field from the speakers to prevent them from interfering with CRT TVs. It should not affect the performance of the speaker at all. Since an in-wall speaker probably wouldn't be close enough to a TV to affect it, there's no reason to go through the extra expense of adding the bucking magnet. And since CRTs are becoming extinct, so are bucking magnets.

Not knowing for sure, but figured that was why the CR9 had a 2nd magnet and also why it was missing from the 381. Thanks for the confirmation!