The mad soundman returns!



Sitting here at the end of my Saturday, drinking Chai Tea and looking over my blogs, I feel a need to write coming on.  It's been a long time since I last entered anything here at all and a lot has gone on since then, other installations, other jobs in the process of being pitched, life is just full of possibilities.



One of my most interesting jobs recently was the installation of a speaker cluster weighing in at 275lbs in a 217 year old church. Many factors needed to be taken into account, such as the age and condition of the architecture, structural limits, the need to preserve the look of the sanctuary and still meet the sound needs of the congregation and the musicians. This is a very challenging job that I think would be interesting from an installer's point of view. I also feel that it may explain to those who are thinking of contracting for a sound system installation in their church what is involved in such a venture.



So, departing from my previous writings, "a tale of endless woe" shall be put on the shelf for now, except as a reference to bring up certain catastrophic events during that installation as a means of highlighting what can go wrong in an installation.



Part One- So yo want to get a new sound system?

Here was a congregation that had a rather low fidelity system that aside from having drivers in it's cabinets blown out, suffered even in it's best manifestations poor vocal intelligibility, tinny and unclear music reproduction, and problems with the sound being too loud at times and still not being able to understand what was being sung, or spoken. Musicians constantly battled with not being able to hear themselves until they literally drowned out the vocals. Coverage was spotty across the seating area, overall I'd say that the sound in this church was a mess. This was quickly recognized by the church congregation, the board of directors, and the musicians. The question was what to do about it, since they had spent a good deal of money on equipment and still they did not have good sound.



In fact, after evaluating what they had in place, I came to the conclusion that really their problem lay not in the mixer, microphones, or the amplifiers, but in the main speakers and their placement.  Replacing these, and properly placing the new speakers, would solve well over 90% of the problems being reported. So, with that aspect of the job established, the question remained of what do we install? To intelligently answer this I needed to examine the building itself much more carefully and design a system that would be the best compromise between the somewhat conflicting needs of aesthetics, function, and demands being made on the system by the congregation, the musicians, singers, and the pastor when he preached his sermons. This brings us to...



Part Two- Archaeological exploration (craftsmen of long ago)

This church was really old, and parts of the building needed restoration. So large was the scope of this restoration that I had to have the stained glass windows examined to determine if in the condition they presently where in they would be able to withstand the low frequency vibration from the new sound system. The last thing I wanted was for the sub woofers to blow out the awe inspiring 180 plus year old stained glass windows!



The sanctuary had absolutely beautiful arched vaulted ceilings in the traditional cross shape that is typical of this construction. Strolling very carefully through the crawl spaces, in some cases literally walking on the arches themselves, revealed several interesting architectural anomalies.



 The mariner's seaport heritage of the area 200 years ago is clear when you look at the arches and vaulted ceiling from above, as the entire vault is constructed like an upside down boat using hardwood boards fitted and laminated together under high pressure. It was an incredible piece of craftsmanship just from this standpoint alone.



The second very interesting thing I noticed as I walked through the upper crawl spaces was that there seemed to be a great many braces spanning in every direction. Many of them where rather thin, in some cases 1" X 5/8", and no two braces where the same thickness or dimension. They where not symmetrical about the two sides of any arch, and some of them spanned across the beams of the arch rather than sprouting out from them.



These could not possibly be structural as such thin wood could not support much weight or stress. The randomness of their placement seemed to make no sense at all. I must confess that I was puzzled until a light bulb went off in my head and I realized the great work I was witness to. These were not structural braces, they were there to dampen, distribute and control vibrations in the arches, and to control the overall resonances of the vaulted ceiling. My God, the entire ceiling was tuned like a gigantic violin! I have pictures that I will share with you in future blog entries, but for now  just imagine the architectural and acoustic challenge of such a task! I was witness to a lost art that in this day and age could not ever be duplicated!



As I gained an appreciation for what was there to work with, I began to better understand how to work with it, and how I was to hang the speaker cluster within this beautiful church. The final destination of the hanging cluster was determined by the architecture and the ideal central point for sound to propagate throughout the sanctuary.



In the end, this hunt for where to hang the cluster brought us to a spot in which no man had set foot in for over a hundred and fifty years. Even with respirators and dust masks, I ended up getting an allergic reaction to long forgotten and currently nonexistent pollen that was trapped in the dust up there. The dust particles were so fine that the coat of dust resembled talcum powder. It was eery up there when we first set foot on those beams. But we found were we could hang our cluster, and where we could drill holes to clear the steel rigging cables in a manner that would not alter the tuning of the arches or the ceiling.



It was time now to go home with my measurements, dimensions, and photographs of the upper spaces and start designing a speaker system that would work in that space and which could be hung. Structurally we could not hang more than 250lbs, so many large format systems simply wasn't an option. Cost would also have been prohibitive. We needed to generate an even coverage of the entire seating area, at levels that were loud but not uncomfortable. We needed a full range system with the ability to plug the musical instruments directly into the system. We needed to improve gain before feedback, overall vocal intelligibility, and sound quality for  music reproduction.



Tune in next week for the solution I came up with, and the manner in which we solved the various conflicting requirements...



Until then, may you have a wonderful week.

The Mad Soundman of AMS Systems

http://amssound.com ~ Sound You Can Feel