This is a classic question asked time and time again. Let’s examine the impact of carpeting in the sanctuary. Carpets kill sibilance – the “tssss” “shhhh” sounds. This takes the life out of the sonic aire. Carpets have no effect on the vowel sounds – a, e, i, o, u. The issue with acoustics is, to a significant degree, the frequency response of the material. Carpet kills treble and does nothing to the bass.
Generally, carpeted floors are not good for congregational singing. They leave the singing space too dull and boomy. On the other hand, if you like the sound of your sanctuary with the current carpet, then you should replace the carpet with a like carpet. If it feels too dead, particularly for congregational singing, consider removing, rather than replacing, the carpet. As an alternative, you might consider Berber which has a very tight weave and does almost nothing to the sound, but it is rather expensive.
The point is that hard surfaces support congregational singing and, generally speaking, churches like to have bright and lively sounding congregational areas. Many churches have carpeted walkways and wood or concrete flooring under the pews. This way there is a quiet entry and exit path with a lively singing space.
Another carpet problem to consider is that when a piano is played over carpet it dulls the sound. Try adding an office chair plastic carpet protector under the piano and you’ll hear how it brightens up and starts to actually sound like a real wood instrument. Choirs are plagued by the same problem. Putting a choir on a carpeted floor is like pulling out vocal chords.
In contrast to this, putting carpet on the floors under the chairs in Sunday school and in office spaces is an excellent idea. The rooms tend to be smaller and there is a lot of “creature noises”, such as shifting chairs, bodies, and papers. Carpet is great at quieting these noises.
Be sure you know the reasons why you want to change carpet before doing so. This will help you select the best solution for your situation. Remember, any change in the acoustics load will appear in the voice of the room. Carpet has lots of fibers which present acoustic friction. Removing carpet changes the amount of acoustic friction in the room, which changes the reverberation of the room.