Chat with Laurie Fincham (Live on Sept 26, 1pm CST)

[hardisj]

(before someone accuses me of spamming the forum; my "interviews" are not monentized. I am just sharing the chat links for those who may find them informative and educational)

Join myself and Laurie for some good discussion on September 26 at 1pm CST. We plan to talk about the following topics:
1) enclosure resonances and their causes
2) the "birth" of a speaker design from a manufacturer's perspective

We will take some questions if we have time. I hope to see you all there and hope you will at least give Laurie a "thank you" for taking time to help us all learn some valuable lessons from someone who has a lifetime of experience*.


*For some history on Mr. Fincham, check out this excerpt from this AES presser:

After more than 20years at THX, Fincham continues to pursue a lifetime passion for designing speaker systems and associated electronics.
Laurie has spent most of his working career in audio engineering, specializing in the theory and design of loudspeakers. He has designed drivers and systems for professional, domestic and musical instrument applications whilst working in turn for Goodmans Loudspeakers, Celestion and KEF Electronics in the United Kingdom and supplementing his engineer’s income by playing 5-string upright bass in various jazz groups. In 1971, while at KEF Electronics, Laurie co-developed the first FFT based measurement system for loudspeaker measurement and modelling. In the early nineties, he moved to the United States to work for Infinity Systems before joining THX in 1998.

Laurie is a life fellow of the Audio Engineering Society (AES), recipient of the AES Silver Medal and a member of the Acoustical Society of America

 

[hardisj]

Going live in about 15 minutes.

 

[Head_Unit]

Fascinating stuff!! Thanks SO much to you and Laurie. If you get a change to talk to him again (and/or Jack Oclee-Brown):
- The Linkwitz transform is based on electrical filters, however the response of the speaker changes with level and perhaps barometric conditions. Which means there will be a delta error-how big a deal is that?
- Concentric designs have various advantages. However especially in the two-way fullrange case, the "horn" (woofer cone) in front of the tweeter is moving, thus there must be some modulation. How large is this effect? Was this ever measured (i.e. by clamping the cone in the farthest in and out positions)?
- For bass, folks typically obsess over a speaker's -3 dB point.*To get the best spec for that implies some kind a maximally flat alignment. For in-room response considering room gain, a more "drooping" alignment focusing on the -6 or -10 dB points would work better, to the detriment of the F3 spec. It would be fascinating to hear how or even if this tradeoff was considered.

P.S. I love car audio too. And made a lot of money in automotive! I think it is now actually for many their best possible listening space. Not that their car system is that good necessarily, but their home environment can have other people and neighbors hindering any effort to listen at decent levels. I still despair at OEMs putting 6 inch "subwoofers" in doors and such, when they could surely shove something bigger somewhere somehow, even in the prevalent SUVs.

*AFAIK this arises out of Richard Small's thesis as a mathematical convenience and electrical filter theory convention. In a conversation in Indiana he agreed with my point above. What a super nice guy too by the way. THAT would be another incredibly cool interview!