SB-6000 question

[Bill_Van]

I brought out my original Technics SB-6000 from storage to check condition and after 44 years from the year I purchased, they still sound great! No deterioration at all.

I was looking in the port and noticed that the woofer is isolated from the rest of the cabinet and wondered what type of system it really is. Assuming the woofer area has dampening material yet the rest of the box is bare.

Just curious as to what it's called.

Edited for a better pic.

 

[kwayde]

Linear phase bass reflex.

https://audio-database.com/TechnicsPanasonic/speaker/sb-6000.html

 

[Bill_Van]

Thanks! I figured same but was thrown off by the isolation looking similar to a folded horn but with a port for better tuning. Funny, after owing them all these years, I can't remember looking inside the port! Since they are operating perfectly, I can't see a reason to remove the woofer to see the inside so I'll let it be until I need to work on them!

Another question.... some pics show a "ridge" on the bottom third of box with no port. Was there a design change or is the port in the back on that model?

Never mind, your link described the "dumped base reflex with a slit port. Somewhere along the way it looks like a tube port was implemented. That is what I have.

 

[Bill_Van]

Another question.... I have the 6000a model. What are the differences between the 6000 and the 6000a besides the port design (tube vs. slot)?

 

[larry777]

Inside these 6000A speakers is a large piece of heavy thick pading that is folded over in multiple layers in the woofer section. The crossover is also well put together with 6 capacitors and nice wiring. I removed my woofer to change the caps and had a good look around when I was in there. Everything looks new inside. Some of the caps in these speakers are also big. Three 68uf, one 33uf, a 22uf and a 15uf.

 

[Bill_Van]

Inside these 6000A speakers is a large piece of heavy thick pading that is folded over in multiple layers in the woofer section. The crossover is also well put together with 6 capacitors and nice wiring. I removed my woofer to change the caps and had a good look around when I was in there. Everything looks new inside. Some of the caps in these speakers are also big. Three 68uf, one 33uf, a 22uf and a 15uf.

Thank you for responding!

I didn't pull the woofer (yet) but looking through the port, I can see a wood (MDF) section that appears to be chamber for the woofer i.e. isolating it from the rest of the box. The bottom (secondary chamber) has no padding/insulation and is raw MDF. This section is to the right of the port and is slightly above but you can still see it.

I did find a clip on You-Tube that shows what you describe but the poster stated it was the SB-6000, not the 6000a.

Doesn't really matter, just curious about the construction/design. They do sound really good for a 40+ year old speaker! All still original components!