Porting: 4645B vs 4645C?

[Doc Mark]

Greetings, All,

I have a question regarding the different ports used in the 4645B and the 4645C. Seems the specs on both systems are very close, if not identical, yet the porting is different. Were there problems with the "B" porting that caused port noise? Otherwise, why does the "C" have that one, huge, port, and the "B" had it's two large (but not huge) ports? Thanks, very much, and God Bless!

Every Good Wish,
Doc

[John]

Greetings, All,

I have a question regarding the different ports used in the 4645B and the 4645C. Seems the specs on both systems are very close, if not identical, yet the porting is different. Were there problems with the "B" porting that caused port noise? Otherwise, why does the "C" have that one, huge, port, and the "B" had it's two large (but not huge) ports? Thanks, very much, and God Bless!

Every Good Wish,
Doc

Well if they were to just keep everthing the same forever no one would ever buy new product!

Trust me both of those systems will knock you back into your lazyboy!!!

I don't think you could hear the port noise when your house is falling down the mountain.

One time when I was having a coffee with Bill at GPA. he told me some people can hear air being passed in and out the vent in the dust caps of 416 woofers,

Now I think my hearing is very good but I cannot hear any air chugging thru the dustcap in those 416's

[Doc Mark]

Good Evening, John,

Thanks, very much! Your thoughts parallel mine, very closely. I got a good laugh out of your answer, though, and so did Sweet Bride!! Thanks, again, and God Bless!

Every Good Wish,
Doc

P.S. Are you going to be anywhere near Milwaukee this June? If so, let's plan to meet up. Did you ever get your amp goodies from Todd?

[John]

Good Evening, John,

Thanks, very much! Your thoughts parallel mine, very closely. I got a good laugh out of your answer, though, and so did Sweet Bride!! Thanks, again, and God Bless!

Every Good Wish,
Doc

P.S. Are you going to be anywhere near Milwaukee this June? If so, let's plan to meet up. Did you ever get your amp goodies from Todd?

Hi Doc, Yes I managed to hook up with Todd on July 22 and picked up my stash. Thanks Todd

Milwaukee in June? Not sure as I was thinking of heading out to the west coast of B.C. that month but will have a clearer picture as June gets closer. Next time I get out to socal perhaps we can put something togeather.

[Doc Mark]

Hi, John,

I'm glad you and Todd got to meet up and "do the deed" in the transfer of your goodies. All's well that ends well!

Yes, if you get out to CA again, please drop me a line. If work will allow, we'd love to have another get together, as we enjoyed with Grumpy and Bart, and also with Todd and Linda (another time). Great fun! I know there are other So. Cal. JBLer's out there, too, and maybe we can expand and have a big picnic someplace. Sounds good. Take care, and God Bless!

Every Good Wish,
Doc

[JBL 4645]

There is slight difference with the JBL 4645B the two ports have 45° bend in them with slightly longer port as it ends up pointing towards the top of the enclosure.








I’ve only seen this once behind the screen at UCI Tower Park years ago. I belaive the Odeon worst sounding cinema in Bournemouth, uses these in screen 6. And they do rumble inside a large medium size auditorium, Star Wars episode 1, when Darth Maul got cut in half by Obi-Wan the force of the shudder vibrated the seat with subwoofer discrete track.

It was years, later I analyzed the differences as some portions of the soundtracks low end over LCR was lost it was there but it didn’t slam or kick as much as the subwoofer/LFE.1 track.

I guess the level was poorly set-up against the LCR fronts because the sub stuck out too much, rather than seamless smooth blending of the lows from LCR pressing on you, as this happens in the home.