Blckshdw
Moderator
As luck would have it, I tried to swear off so many projects this year, and try to save up some money. So of course, something wants to pop up. Couple weeks ago my 20+ year old Bose Accoustimass bass module started having a resonance issue. Was having issues with certain midrange frequencies, acoustic guitar, certain automotive related shows where the engines hit high RPMs, and certain vocal ranges.
So what do we do around here when something goes sideways on us? Take it apart and poke around of course! Got the back cover off, and removed the amp/crossover unit easily enough.
![20240224_125603_resize.jpg 20240224_125603_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168042-cabd01a8fb3557ab04d9e77f82726518.jpg)
![20240224_130225_resize.jpg 20240224_130225_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168043-43b8db4275fea81ae375fc09fc994d52.jpg)
![20240224_131119_resize.jpg 20240224_131119_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168044-44966aa6c987f8669adbf402a1ea498b.jpg)
With the connector to the speakers exposed, decided to do a little test, take the module out to the EXT and connect it to the subwoofer outputs on the amp there. Played pretty nicely, although could hear a slight distortion, which sounded like it was coming from the back corner of the box.
![20240224_132718_resize.jpg 20240224_132718_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168045-0b2e3307a20a01618e0928ba794c2328.jpg)
No amount of pressure in any spots made any change, so decided to pry the inner rear cover off exposing the 2 speakers. After getting the screws out, stumbled onto the solid strand wires, wound around the speaker connector posts. The wires had barely enough slack to get them taken out. Was able to connect them to the stereo receiver in the bedroom for another test. Neither speaker sounded bad when being held in my hands, even at high volume.
![20240224_133548_resize.jpg 20240224_133548_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168046-504f1e118bf6d6372c29734fcc7fd3a4.jpg)
![20240224_135648_resize.jpg 20240224_135648_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168047-3f8b894d20e675d97aee4d192dced778.jpg)
![20240224_135940_resize.jpg 20240224_135940_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168048-cbc632c4d0ca1e403461444959bc5fd9.jpg)
![20240224_143224_resize.jpg 20240224_143224_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168049-1c1b4fad896f1986b79046b6f19275c7.jpg)
So at this point I'm kinda stuck, with no obvious problem. As cheap as midrange speakers are these days, I could drop a few coins on some 5.25" and see if they play nice. I know they wouldn't be perfect since this box was likely designed around these specific speakers, but the internals of the box are still pretty rigid. So I think aged speakers that have seen a lot of use over 2 decades are the likely culprits.![Undecided :undecided: :undecided:](/forums/smilies/undecided.gif)
So what do we do around here when something goes sideways on us? Take it apart and poke around of course! Got the back cover off, and removed the amp/crossover unit easily enough.
![20240224_125603_resize.jpg 20240224_125603_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168042-cabd01a8fb3557ab04d9e77f82726518.jpg)
![20240224_130225_resize.jpg 20240224_130225_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168043-43b8db4275fea81ae375fc09fc994d52.jpg)
![20240224_131119_resize.jpg 20240224_131119_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168044-44966aa6c987f8669adbf402a1ea498b.jpg)
With the connector to the speakers exposed, decided to do a little test, take the module out to the EXT and connect it to the subwoofer outputs on the amp there. Played pretty nicely, although could hear a slight distortion, which sounded like it was coming from the back corner of the box.
![20240224_132718_resize.jpg 20240224_132718_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168045-0b2e3307a20a01618e0928ba794c2328.jpg)
No amount of pressure in any spots made any change, so decided to pry the inner rear cover off exposing the 2 speakers. After getting the screws out, stumbled onto the solid strand wires, wound around the speaker connector posts. The wires had barely enough slack to get them taken out. Was able to connect them to the stereo receiver in the bedroom for another test. Neither speaker sounded bad when being held in my hands, even at high volume.
![20240224_133548_resize.jpg 20240224_133548_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168046-504f1e118bf6d6372c29734fcc7fd3a4.jpg)
![20240224_135648_resize.jpg 20240224_135648_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168047-3f8b894d20e675d97aee4d192dced778.jpg)
![20240224_135940_resize.jpg 20240224_135940_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168048-cbc632c4d0ca1e403461444959bc5fd9.jpg)
![20240224_143224_resize.jpg 20240224_143224_resize.jpg](https://gmtnation.com/forums/data/attachments/168/168049-1c1b4fad896f1986b79046b6f19275c7.jpg)
So at this point I'm kinda stuck, with no obvious problem. As cheap as midrange speakers are these days, I could drop a few coins on some 5.25" and see if they play nice. I know they wouldn't be perfect since this box was likely designed around these specific speakers, but the internals of the box are still pretty rigid. So I think aged speakers that have seen a lot of use over 2 decades are the likely culprits.
![Undecided :undecided: :undecided:](/forums/smilies/undecided.gif)