Dear Community,

I am pleased to announce the addition of another video lecture on topics of interest to performers.

My talk on Room Acoustics for Performers is now available in several chapters for viewing.

This lecture was given at the 5th L1 Musicians Conference, in Little Switzerland NC in May 2008.

We hope you enjoy it and will comment on it here.

With best regards,

Ken

This message has been edited. Last edited by: Ken-at-Bose,

Hi Ken!

I really enjoyed re-living your presentation this evening and truly appreciate the efforts that went into capturing, editing and presenting your presentation. Kudos to Eve for the fine job in editing!

One comment. I had problems with Ch. 6 & 7 of the presentation. They seemed to load OK, but would only "play" a portion of the video and then stop. I tried several different attempts, but they seemed to stop at the same point in each chapter, as if the entire chapter was not uploaded properly.

Can you view them in their entirety without problems? It may be on my end of things, so I am curious if anyone else is having the problem. I didn't have the problem with any other chapters.

I feel so fortunate to have had the opportunity to be presented this information and consider it a valuable asset in furthering my knowledge of our performing venues and sound! Thanks again!

John

Hi John,

Checking at this end. I'll let you know what I find.

Hi John,

Thanks for posting about this. Sometimes I cannot see these kinds of issues.

I am re-uploading the files now. It looks like that should be complete in 5-10 minutes.

Let's see if that helps.

EDIT:
# 7 looks okay - I think there may be a problem with #6.
I'm working on it now.

Hi ST!
Fixed. Your magic worked. No problems viewing them now...thanks for looking into it! John

Hey Ken,

Thanks for sharing your great presentation with us via the web. It reminded me of just how rich the LS experience was. We had a great time and learned so much.

Also, it's so special when I see a post by one of the LS participants. It brings back some great memories of the conference. It really is like a family.

Thanks to "Evie Wonder" for the fine video work. What a nice and talented lady.

Rick

Hi Ken

This is fascinating. You are describing exactly the problems I experience in a room. These problem didnt make sense to me at the time and I didnt know how to fix.

The graph of frequency vs Db dropoff is a bit blurry on the video. Is this graph published in a text book somewhere? Is there a textbook explaination of the phenomenon Chris described with the flat seated audience? Where can I read more on the subject?

PS Apologies for being an engineer. Can help myself.

Cheers

Ken,

Would it be mathematically possible to make a convex ceiling in my kitchen powerful enough to eliminate hearing my wife hollaring at me? If so please post detailed plans so I can meet with my contractor immediately.

Great presentation!

quote:

The graph of frequency vs Db dropoff is a bit blurry on the video. Is this graph published in a text book somewhere? Is there a textbook explaination of the phenomenon Chris described with the flat seated audience? Where can I read more on the subject?

Hi valvenerd,

I'm glad you liked the lecture. Really glad.

The graph is from David Egan's book "Architectural Acoustics". I like the book very much and recommend you pick up a copy.

With best regards,

Ken

Very useful presentation, Ken. I've encountered some version of every problem you described. I watched the videos when they were first posted, and again just now.

The only thing missing from the preso is how a cylindrical radiator addresses the problems presented by an acoustically challenging space. For example in an outdoor setting without raked seating, is the audience-interactive echolet effect reduced when using cylindrical radiators like the L1? I don't see offhand why it would be.

Also, would the cylindrical wavefront from an L1 reduce the beneficial effect of articulated ceiling reflections, since less energy is being reflected to the back rows?

My personal experience is that L1s perform better than anything else I've used in challenging places like winery casking rooms, warehouses, and outdoors. (Sheesh! Why do I take such gigs? ) So, the reason it works is academic. But inquiring mind wants to know.

--Rick

GOOD QUESTIONS.

And you've pointed out an important omission in the talk.

Let me carve out a little time to answer.

Please stand by (or better, turn notifications on for this thread).

Ken

I eagerly await your informed response

quote:

Originally posted by rikart:
...in an outdoor setting without raked seating, is the audience-interactive echolet effect reduced when using cylindrical radiators like the L1? ...

Like Ken, I'll have to consider this a bit more.

quote:

Also, would the cylindrical wavefront from an L1 reduce the beneficial effect of articulated ceiling reflections, since less energy is being reflected to the back rows?

I'm pretty sure the answer to this is "Yes" ... for the L1 amplified sound. Depending on the setting, room usage, etc., there could still be a lot of good reasons for the articulated ceiling design.

quote:

Also, would the cylindrical wavefront from an L1 reduce the beneficial effect of articulated ceiling reflections, since less energy is being reflected to the back rows?

In general, L1 classic, Model I and Model II systems engage the ceiling and upper walls of rooms much less than conventional speakers used for live music.

At the same time, their radiation pattern (mostly out and to the sides, but little up and down) means the sound doesn't fall off with distance anywhere near as fast as a conventional speaker. Hence, they "reach" to the back of the room better.

These are unusual properties and can be used strategically, as Rikart suggests. (Occasionally, they are misapplied.)

L1 systems tend to minimize the affect room acoustics has on sound quality. They give a high degree of consistency from venue to venue.

If most venues were gorgeous acoustically, you probably would not like this feature of the L1 technology. But since they aren't, this property, on average, is and advantage.

quote:

in an outdoor setting without raked seating, is the audience-interactive echolet effect reduced when using cylindrical radiators like the L1?

I'm not exactly sure what you mean here, and could use a little help.

Ken

quote:

Originally posted by Ken-at-Bose:

If most venues were gorgeous acoustically, you probably would not like this feature of the L1 technology. But since they aren't, this property, on average, is and advantage.

quote:

in an outdoor setting without raked seating, is the audience-interactive echolet effect reduced when using cylindrical radiators like the L1?

I'm not exactly sure what you mean here, and could use a little help.

Ken

Thanks, Ken. On the few occasions when I've played in rooms that were 'gorgeous acoustically' I was usually using house sound and a dedicated sound person. But most of the time I'm in a big echo chamber or outside, both of which settings really benefit from the L1's cylindrical wavefront.

My question about echolets refers to the part of your video where Chris Ickler describes phase cancellation at 125 Hz as the sound wave diffracts over each row in the audience when there is no raked seating. Seems like the only way to defeat the effect would be to broadcast from a fairly high stage and to tilt the L1s down to simulate a degree of raked seating. Images from the preso attached.

Hi Rikart,

Yes, you have to avoid glancing incidence to avoid the cancellation over raked seating.

In the case of the L1 systems, the high amount of side reflections (except in outdoor venues with no side walls) help alot with any glancing incidence cancellation.

I love this stuff.

Ken

quote:

Originally posted by Ken-at-Bose:

I love this stuff.

Ken

You're in the right business