Sony SS-1800 - Insulation blocking port?

[Styles B]

Hi folks,

I'm restoring some '70s Sony SS-1800 speakers that someone had put out at the curb. I don't expect them to be hi-fi quality (it's more of a fun project), but I'm actually pretty surprised by the build quality. As they were, they were really lacking bass. The surrounds of the big 30cm woofers had dried out, so I used some brake fluid and it has slowly worked away to make them much more pliable. I've been restoring the finish of the beautiful walnut cabinets (they were in rough shape) and I'll be replacing the capacitors (they're on their way) too.

My big question is, as I've gotten inside, I was surprised to see that the front ports have a wad of insulation stuffed in there towards the back. I thought ports were meant to be open, but these clearly left the factory with this damping material. Anyone have any thoughts on whether this approach has logic?

Cheers.

 

[maxhifi]

It provides some acoustic resistance and blocks the reflected mids and upper bass from the rear of the drivers coming through the enormous port. Some modern speakers are provided with a foam plug to achieve the same thing. Definitely do not change this.

 

[Styles B]

It provides some acoustic resistance and blocks the reflected mids and upper bass from the rear of the drivers coming through the enormous port. Some modern speakers are provided with a foam plug to achieve the same thing. Definitely do not change this.

Good to know. Thanks for the response.