Coytee Posted June 26, 2006 Share Posted June 26, 2006 Was sitting there in front of the Khorns, listening to some Moody Blues thinking about cranking it up... then my mind raced to the anechoic chamber and our listening session of the Jubilee INSIDE the chamber. Here's what happened: Several of us where there and Roy asked us (or we asked him?) if we could go inside the chamber. We went inside and saw the Jubilee there. He smiled & during his talks, asked if we wanted to hear it. We said yes, he closed the door and played a test tone. He went easy on us and didn't crank it up. That last thought about him NOT cranking it up is what came to me when i was listening to the Moody Blues tonight. Let's say a person was inside the chamber with the Jubilee. I don't know what it's capable of but I guess it can get pretty loud. If it is playing at it's MAXIMUM loudness and the person is standing in front of it, clearly the person is going to get assulted with the full direct output of the speaker. What if however, the person is standing BEHIND the speaker? Since there are no reflected sounds, will it be strangely quiet with some quiet sound coming to them from (through) the rear of the unit as well as some sound wrapping around the speaker? Would it be dead quiet?? clearly that can't be the case? Seems to me the more I think about it that it could be quite a disparity of sound as one walks around the speaker getting blasted with sound on one side and possibly having no sound on the other in spite of being in the same room? Ok, anyone else want to fess up about having meandering thoughts/questions like this or am I the only one who's going to humilate themself? [8-|] Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 26, 2006 Share Posted June 26, 2006 Coytee, I think that's a great question. I suppose you'd find out a couple of things. One is how good the anechoic chamber really is. If it reflected absolutely no sound, or just a little. Also, if you were standing behind the Jubilee, I think you probably would find out how much sound radiates through the Jubilee cabinet, which would be undiscernable, I'd think, in an ordinary room. I have one more question to throw in to ponderland... Say a man is in the anechoic chamber and he says something, and there is no woman in the anechoic chamber to hear him say it.... is it still WRONG? Quote Link to comment Share on other sites More sharing options...
WMcD Posted June 26, 2006 Share Posted June 26, 2006 All such thought experiments are worthwhile. You see some reports of speakers in an anechoic chamber. Generally, the low freqs do radiate to the back. The higher ones beam to the front. I'll agree that being inside an anechoic chamber can be a bit disconcerting. It is so quiet. An otherwise loud hand clap is dull. I think you can recreate the chamber by going outdoors. This is something for you to do. Try a hand clap in your living room and listen closely a few times. Then go outside to the park or back yard on a quiet night. This experiment might be better if you have a companion clap in the room, and outdoors at the same distance. Maybe try Days of Futures Past on a boom box in both situations. A breakthrough album. Did you realize that the opening cut is the reverse recording of the gong at the end? Smile. Gil Quote Link to comment Share on other sites More sharing options...
rcarlton Posted June 27, 2006 Share Posted June 27, 2006 Roger Russell wrote about McIntosh's Anechoic chamber. Doesn't answer your question, but provides food for thought. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 27, 2006 Share Posted June 27, 2006 Isn't this a new take on the joke 'If Helen Keller was in a forest and a tree fell....." I want some of what he's smoking for dessert! LOL[:^)] M Quote Link to comment Share on other sites More sharing options...
DrWho Posted June 27, 2006 Share Posted June 27, 2006 I think a quick look at any speaker's polar response will answer your question...sound does travel in all directions from a speaker - just that the rear wave is considerably quieter (hopefully). Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 27, 2006 Share Posted June 27, 2006 I dig the new avatar Doc! Make sure to give Fini a 'byline'! Quote Link to comment Share on other sites More sharing options...
Andy W Posted June 29, 2006 Share Posted June 29, 2006 The edges of the faces of the cabinet (or horn) become a diffraction edge for the sound wave coming off the front of the speaker. This edge will become another "source" of radiation from which the sound will propogate. This is how the sound "wraps" around the cabinet. It is also the source of frequency lobes on and off axis as the diffraction edge constructively (adds) or destructively (subtracts) interferes with the sound from the driver. At some frequencies this will cause on and off axis peaks and dips in the response curve, which are tied to the dimensions of the cabinets and the location of the driver on the baffle. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted June 30, 2006 Share Posted June 30, 2006 I think a quick look at any speaker's polar response will answer your question...sound does travel in all directions from a speaker - just that the rear wave is considerably quieter (hopefully). doesn't a speaker radiate in a doppler pattern which is by no means linear Quote Link to comment Share on other sites More sharing options...
Deang Posted June 30, 2006 Share Posted June 30, 2006 What I find interesting is that PK didn't have access to a chamber for decades after designing the Klipschorn, and once having access to a chamber -- it seems no design changes either in construction, drivers, or filter -- were implemented based on anything that was discovered from the chamber measurements. Am I wrong? Just curious. Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted June 30, 2006 Share Posted June 30, 2006 maybe the saying "why fix it when it ain't broke" On the other hand, anechoic chambers have their place in the analysis world but I think PWK was more of a real world type person that compared his speakers to real world scenarios like live concerts which is probably a 180 from anechoic Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 1, 2006 Share Posted July 1, 2006 What I find interesting is that PK didn't have access to a chamber for decades after designing the Klipschorn, and once having access to a chamber -- it seems no design changes either in construction, drivers, or filter -- were implemented based on anything that was discovered from the chamber measurements. Am I wrong? Just curious. Dunno - I know he was greatly involved with the creation of T/S parameters and was a very good mathematician so he probably did the raw wave equations to calculate the shape of the khorn. I do know that they spent a lot of time measuring the khorn and trying all sorts of stuff. They even tried just about every high performance driver they could find to see if they couldn't increase the efficiency any more....seems the horn dictates most of the acoustical behavior and not so much the driver itself. And apparently if you unfold the khorn it has a nearly ruler flat response and extension to 1.5kHz? I'm not sure on the actual number - it's been information overload lately. The problem with complex systems like the khorn bass bin is that any small change made in one place affects everything else - essentially requiring an entire rebuild. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 1, 2006 Share Posted July 1, 2006 This is a fine example of the genius of PWK, from my perspective as a non tech type. It is quite impressive, IMO, for folks to design well using the tools now commonly available. To have done what Mr. Paul did, previous to the development of the tools is amazing. And, as posters above have mentioned, he was a key person in development of the tools. I would imagine that in the development of the tools, he was seldom surprised. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted July 1, 2006 Moderators Share Posted July 1, 2006 Daddy Dee : " I have one more question to throw in to ponderland...Say a man is in the anechoic chamber and he says something, and there is no woman in the anechoic chamber to hear him say it.... is it still WRONG? " Now Daddy Dee you know that is a silly question, Of course he is still wrong. Quote Link to comment Share on other sites More sharing options...
hwatkins Posted July 2, 2006 Share Posted July 2, 2006 Daddy Dee : " I have one more question to throw in to ponderland... Say a man is in the anechoic chamber and he says something, and there is no woman in the anechoic chamber to hear him say it.... is it still WRONG? " Now Daddy Dee you know that is a silly question, Of course he is still wrong. That is correct - the chamber is the results of the laws of nature and in no way changes the rules we live by.... BTW - our friend from Klipsch and the young Doctor got it right on the behavior of sound waves... Quote Link to comment Share on other sites More sharing options...
DizRotus Posted July 2, 2006 Share Posted July 2, 2006 Somewhat similar to the posed hypothetical is a live performance outdoors or in a large auditorium. Without on stage monitors facing them (or headphones/earpieces), the performers cannot hear themselves; it can be very disconcerting. Quote Link to comment Share on other sites More sharing options...
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