Klipsch anechoic chamber turns 40 years old

[dtel]

6 hours ago, Islander said:

You weren’t tempted to do a bit of beatboxing while you had the room to yourself?

Uh no, nothing that involves anything resembling musical talent, well not counting pushing a button or turning something on.

 

But to be there alone with it quiet outside and even morose inside it was strange, it just gives you a kind of uncomfortable feeling. So after a while I got up and went walking through the plant, this did not help, this felt strange also, only a few lights by each station, I ended up going back to the lab until the meeting was over. 

[Islander]

That sounds like a really strange and slightly disturbing experience.  When I was a youth, living in the woods about 40 minutes from Quebec City, my brother and I would sometimes go snowshoeing in mid-winter in the forest, on bright moonlit nights.  Being in a place with a deep blanket of snow is amazing, because the noise floor is much lower than normal.  We’d hear ourselves when we were moving, but when we stopped, there seemed to be no sound at all.  That was really pleasant, though.

 

At Expo 67, the World’s Fair in Montréal, there was a Science section, and one of the exhibits was a tunnel of silence.  It was arch-shaped, with a rounded top.  The floor was maybe 8 feet wide and 30 or 40 feet long, and the wall/ceiling was finished in black inside.  This had the unnatural silence that you experienced.  The area around it didn’t have any loud noise sources, but in the tunnel it was silent to an amazing degree, and it felt odd.  I left after a few minutes, but I could see how it might have become disturbing if I’d stayed there for a longer period.

[OO1]

On 3/31/2020 at 3:31 PM, Islander said:

 

 

At Expo 67, the World’s Fair in Montréal, there was a Science section, and one of the exhibits was a tunnel of silence. 

-Montreal-Quebec-Canada Expo 1967

 

 

[Islander]

Thanks for that video.  Pity there was no audio for it.  I saw what was probably my first rock concert at Expo 67, in the Pavillon de Jeunesse.  It was some guy I’d never heard of, because he wasn’t getting any radio air play at the time.  His name was Bob Seger and his band was The Bob Seger System.  They were pretty good, as I recall.

 

The next time I heard of him was a few years later, when he was playing with his Silver Bullet Band.

[OO1]

34 minutes ago, Islander said:

Thanks for that video.  Pity there was no audio for it.

Notre-Dame Island is Man Made ,  they dug , the Decarie Highway  and the Montreal Metro  to create an Artificial island -----it now houses the Casino de Montreal and the F1 Circuit Gilles Villeneuve -

 

[Islander]

I knew one of the islands was artificial.  I may have confused that one with Nuns’ Island.  I didn’t live in Montreal, so I wasn’t super familiar with the place.

[mark1101]

During one of our visits a few of us were inside the sealed chamber when Roy was doing some measurements.  Sort of weird.  We were laughing.  Covered our ears after the first one.  He was doing the same type of up sweeps you can do with REW at home.  I believe the mic was 10 feet from the speaker, which was a lascala.  The purpose was to hear the sound all around the speaker in the chamber to understand that sound actually is all around and behind the speaker.  Hence the "bubble".

[Chris A]

41 minutes ago, mark1101 said:

The purpose was to hear the sound all around the speaker in the chamber to understand that sound actually is all around and behind the speaker.

That was an enlightening experience.  The difference between the K--402 and the K-510 horns was pronounced during a visit in 2009 to the chamber.  I also got to hear the degree of sound diffraction in and around the rear and sides from the cabinet tops and the HF horn stand itself, and how intense those reflections actually were, and how complex their polar patterns were while walking around the assembly.

 

Large horn mouths can control their polars to a much lower frequency and hearing this both in the chamber and outside the chamber told me a lot.  Roy also had to spend a lot more time with his "salt and pepper EQ" to get the K-510s to sound about right in the listening room.  It was a snap (relatively speaking) for the K-402.  That told me a lot more.

 

We learned a great deal in the two days we were there, and the difference between the in-chamber and in-room (the listening room just next to the chamber) was something that I probably won't ever forget.  It took a while to assimilate all that Roy demonstrated over those two days, but I believe it was the real beginning of my audio education. 

 

Thanks again, Roy.  Priceless wisdom was shared in those sessions.  PWK's investment in the early 80s was a good one (and necessary, I believe).

 

Chris

[Coytee]

402

 

 

 

 

 

 

 

 

 

 

 

510

 

[Coytee]

 

It was (for me) a revelation on how much more quiet the 402 was when standing behind it.  Really showed how the sound wraps around the 510.

[hanksjim1]

Microsoft claims world's quietest room...

 

https://www.cnn.com/style/article/anechoic-chamber-worlds-quietest-room/index.html

 

 

[Travis In Austin]

On 5/21/2021 at 6:59 AM, mark1101 said:

During one of our visits a few of us were inside the sealed chamber when Roy was doing some measurements.  Sort of weird.  We were laughing.  Covered our ears after the first one.  He was doing the same type of up sweeps you can do with REW at home.  I believe the mic was 10 feet from the speaker, which was a lascala.  The purpose was to hear the sound all around the speaker in the chamber to understand that sound actually is all around and behind the speaker.  Hence the "bubble".

You and I went in there, we had our hands pressed up against our ears as hard as we could, the sound is piercing. If makes little or no difference above 10K whether you have your ears covered or not, the perceived spl is nearly the same. We were both like "whoa' at the same time, then they turned the lights off and ran another one. We both ran out 9f there as fast as we could.