Tuesday, February 11, 2014

Speaker Retrofit

I came up with a suitable solution for the speaker replacement. The original speaker was designed to fit into a very shallow box. This speaker is not made anymore and there is not direct replacement for it. I also could not find anyone who would recone it either. So I looked for another solution. I came up with mounting to small round speakers in the same space as the 4" x 6" speaker using a adapter plate I made.

Original 4" x 6" speaker mounted with #8-32 weld in studs

Cardboard template to make an adapter plate from

Template transferred to sheet metal

Sheet metal cut out
 Sheet metal mounting holes drilled and trimmed

 Speaker fitting

One of the two speakers
 Sheet metal marked for the speakers

 Pilot hole for the jig saw

 Speaker holes cut out

 Speakers test fitted on the sheet metal adapter plate.
 I used #4-40 flat head brass screws

 Test fit into the enclosure

Adapter plate painted flat black and speakers mounted
 I added some strip caulk to help reduce metal to metal vibration

All mounted and wired with strain relief. I also made a plug for the speaker to radio interface.