JBL 4401s

[jcrobso]

Back in the late 1950's when I started getting interested in Hi-Fi the battle was raging, bass reflex vs sealed box!
Acoustic Research (AR) speakers were the rage in the early 1960's.
The concept was to make the LF driver with a very lose(complaint) suspension, the box was filled with fiber glass and sealed tight. The trapped air stiffens the LF driver, the box is a variant of the infinite baffle. The box filled with fiber glass tricked the LF driver into thinking that it is in a larger box than it really was.
It would be interesting to see how and L88 woofer would react if you filled the box with fiber glass and plugged the port. I'm might try this with one of my L88s if I run out of things to do.
In 1964 I had chance to spend 3 hours just listing to just speakers, JBL,AR, Jensen, Empire, etc. I did a lot of comparing AR to JBL and I all wise liked the JBL ported boxes over the AR, I have been a JBL person since then. John

[grumpy]

It would be interesting to see how and L88 woofer would react if you filled the box with fiber glass and plugged the port.

Others thought so too:

http://www.audioheritage.org/vbullet...ad.php?t=15025

[JoMoCo]

Zilch, Is post 64 your latest / last LF crossover version or did you improve to a more current version for this app?
Thanks Jon

[Zilch]

I believe that's still what I'm using for the 123A lowpass.

It's in the E'Wave thread somewhere, as well....