Acoustical Question
  • SalieriSalieri
    Posts: 2,045
    I won't go into details of the backstory, it's not very interesting anyway, but in order to fix a recurring problem, my parish has decided to replace our current plaster ceiling with a wooden one. We are very fortunate to have many professionals among our parishioners, including an architect (who is also an excellent woodworker) and a contractor, and they have taken it upon themselves to complete this project.

    The only question that everyone seems to have is about acoustics: Will a wooden ceiling help or hurt the space acoustically. I posit that it will help them, going by the notion that most of the world's greatest theatres and concert halls are wood, but I really don't know, not being a acoustic engineer. So, I'm asking y'all for your opinions: Will our acoustics most likely be helped or hindered by changing from plaster to wood? Thanks.
  • ClergetKubiszClergetKubisz
    Posts: 1,805
    Wood is a harder surface, so it will probably help. I'm not an acoustician, either, but it makes sense to me. The shape of the room will affect it as well. I read a dissertation on the shape and construction of opera houses throughout history, and the shape DEFINITELY affects the acoustics.
  • Liam
    Posts: 2,998
    What is the shape of the vault (ceiling) and general proportions and materials of the other main surfaces (floor/walls) of the space?
  • SalieriSalieri
    Posts: 2,045
    The shape of the church is your average rectangle: the length of the nave is about twice the width; the height of the side walls is maybe lightly less than the width of the building; the vault is simply triangular, like the roof, with exposed rafters.

    The pews and the floor under the pews are wood (Oak), the stalls and the main altar and reredos are wood (Oak), the side altars are plaster (oddly enough); the walls are plastered; the isles and sanctuary are carpeted (bleh).
  • Liam
    Posts: 2,998
    Thanks for the detail; it can matter. In that case, I would imagine a wooden vault would add resonance. But it may also depend on what, if anything, is immediately above the wooden layer.
    Thanked by 1BruceL
  • CharlesW
    Posts: 8,287
    All woods are not created equal. Some absorb more sound while harder woods better reflect it. Whatever you do, don't get a recording engineer to evaluate your space. It will likely becomes as acoustically dead as a studio - witnessed it happening at a local parish.
  • For accurate predictions, you need an acoustics consultant who understands live sound and has a proven record of working with churches.

    They will measure various aspects of the space and use modelling tools to understand how God's laws of physics apply in your situation.

    Anyone else is guessing.
    Thanked by 2Liam Spriggo
  • Adam WoodAdam Wood
    Posts: 6,270
    Especially in the case of the soft woods usually used in building construction (namely, pine and spruce), the seal and finish will matter. To over-simplify -- go for hard and shiny if possible.
    Thanked by 1Liam
  • Liam
    Posts: 2,998
    Tangent: for folks who've never seen a glorious wooden roof, here's the famous double-hammerbeam angel roof (constructed in the generation before the ravages of the Reformation) at St Wendreda's in March, Cambridgeshire:
  • bhcordovabhcordova
    Posts: 420
    Wow! How beautiful! I doubt there are even a handful of carpenters or millwrights that could do that today!
  • Liam
    Posts: 2,998
    There are a number of angel roofs in England (especially East Anglia), but that is one of the most famous. Yes, the Continent has many glorious stone vaults, but these wooden roofs of parish churches in England are among the special glories of that island.

    Here's a visual, with music (to get back to music...):

    I know lots of American Catholic sacred musicians may dream of French Gothic expanses (I prefer my Gothic in smaller jewel boxes (the various chapelles of northern France) or the Backsteingotik of northern Europe), but in my dreams I would likely choose a not-huge Romanesque church with fine clerestory lighting and a wooden roof like these....
  • Adam WoodAdam Wood
    Posts: 6,270
    Pre-reformation England is Best England
  • Eamon Duffy might well agree.
  • Chart on Page 26

    Plaster and Wood are close to equal in sound reflection. Other materials listed.

    What is supporting the wood and plaster behind it is also essential in making the decision.

    Sabinite plaster is an acoustical deadening material once very common in churches, including Riverside in NYC while Fox was there. Since been eliminated, dramatically improving the musical acoustics and making the organ much more enjoyable to play.
  • I just started working for an acoustical surfacing company (, and they have two wood divisions, Architectural Surfaces and AcoustiGreen. I would be chuffed to bits if your architect spect our company, but the sites may give an idea and info on what is possible acoustically.

    Incidentally, my job there is going to involve learning acoustics so that I can assist in modeling rooms to determine best acoustical solutions. Any ideas for studying acoustics at a deep level, including school?
  • School will not be as helpful as interning at a firm the likes of:

    Almost acoustical engineering study is concerned with deadening rooms, structures and...if they could, entire cities. The money is in acoustical deadening and control.

    There are a few firms, like Riedel, that are oustanding at treating even existing structures to make them acoustical gems for liturgical worship.
  • jefe
    Posts: 113
    The surface of the wood material makes a big difference. A hard surface will reflect the high frequencies. I used a dark red fibre glass laden porch paint on some of our loft surfaces to good effect, especially when combined with dumping the carpeting. It pumped the highs, and was very tough as you would expect a porch paint to be. If you have an older parish, which, i will surmise is almost everyone on this forum, what is the first frequency range that goes especially in older men? The thickness of the wood makes a big difference too. Our loft has 1874, 1-1/2 inch thick, tongue and groove planks, 6 inch wide, very old and hard Douglas Fir floors which both resonate and reflect most frequencies well. Our old stair well to get access to the loft acted as a black hole for long frequencies so I cut a piece of plywood (as thick as I could lift into place) with the same porch paint applied, to close the black hole for Compline thus improving the low freq. projection. It's probably illegal but the local constabulary has bigger fish to fry.
    After 38 years of playing the concert halls of the world with the LA Phil, I have a lot of memories of great acoustic spaces. Why is this even in the mix? Only that there are a lot of dependent issues. The Musick Verein in Vienna sounds great but it has nothing in common with Symphony Hall Boston, also a great hall, with almost every construction aspect different. Nothing compares to playing the Bruckner 4th in Ghent, which was a late medieval, all stone cathedral. The only reason it worked at all with the 6 second echo (at FF), was because the harmonic rhythm was so slow. Yes, I took an Acoustics of Music class at University, really my favorite class while there, and discovered that the more i learned about acoustics, the less I knew. A few thumbs are these: try to keep the surfaces made of the same material, else they cancel each others' resonance out. Thicker and harder is better than thinner and softer. No parallel surfaces, unless you enjoy flutter echo. Ditch the rugs. Almost anything is better than soft plaster. If you must plaster, consider HydroCal, a very hard alabaster plaster that reflects well and stands up the Anglican Abuse. 8<)<br />jefe
  • jclangfo
    Posts: 75
    There is a tradeoff between how well sound projects and how much it echos. As an undergrad I played at a church with a terrible echo problem.
    Thanked by 1Reval
  • francisfrancis
    Posts: 7,440
    you main gain some knowledge by comments here but you will not get your answer here. you must do modeling to get a true projection that takes into account shape, reflectiveness of materials, placement of instruments and musicians, etc. I don't think it's as simple as replacing one material with another. JMHO
  • Fairly subtle things can make a huge difference with acoustics. Our choir loft was made deeper, and this had the unintended result of causing the rail to absorb/reflect a much greater portion of the sound, particularly making vowels less distinct for whatever reason, and making the sound quality in the rear of the nave much poorer.
    Thanked by 1Liam