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Should a corner bass trap run the entire height of the room?

If not, should they be at the top, in the centre or at the bottom?

I'm actually in the process of re tuning my room to accommodate my new concert grand. My 2" panels worked for the smaller piano but kill the highs and clouds the bass for the larger piano so it was recommended to add broadband bass traps all around.

From what I learned you will want the thickest material 6" or so broadband bass traps w/ diffusion- as many as you can tolerate and yes you will want floor to ceiling for the corners, but that may only be just a start. The diffusion will give the room ambiance. I decided to go the other way around and start with traps on the walls first since I really don't like the corner ones in my smaller room. Check out GIK Acoustics in the UK


You can have the diffusion plate outside or underneath the fabric and you can also do it yourself to save money

Bass traps should run the entire length of the wall to be effective.

So on the one hand, piano designers go to great lengths to improve the sound of the bass of pianos, and on the other hand, acoustic "experts" add bass traps to reduce the sound of the bass in pianos.

That is NOT how bass traps work. Its not about reducing the sound at all, Its about frequency control and gain. You will get way better and more clear bass sound with traps

Gain has everything to do about reducing the sound, and why should we tune pianos just to have someone else control the frequency?

All I know is bass traps and acoustic panels make a world of difference for residential rooms for acoustic and hi fi systems. It's about sound reflections not direct sound from the source. What you are trying to do is delay the amount of sound going into your ears as if you were in a larger hall were that happens naturally. This is not really a subjective argument, Plenty of info out there on the net.

It's more the acoustic response of the space to the bass, and not the design of the piano itself. Same goes for audio speakers in professional and performance settings. Software is used to analyze the acoustic response of the room with "pink noise". Then the data is used to set the equalizers on the sound system to insure a natural sound in the venue.

Because an untreated room is "controlling the frequency" already, and not in a good way. Bass frequencies have a tendency to reflect a lot in the corners of a room, they build up there and distort the sound coming back at you. In other words, they (Absorption panels, Bass Traps, etc.) help you to hear the piano, as opposed to the piano plus the distorted reflections from the walls.

I have never had problems hearing a piano, so I do not need any of this nonsense.

Most recording studios have acoustic treatments of the space, including those I have tuned pianos for.

When I am discussing voicing of a piano with a customer, that most often includes a discussion of the room that the piano is in and its effect on the sound of the piano, along with some suggestions of simple things they can do to improve the performance of the room for the piano. The best result comes from addressing the needs of the piano and those of the room.

You might want to read up on this stuff, BDB. It's pretty much common knowledge.

Nonsense? Please. This is right out of Basic Studio Design 101, as important as avoiding parallel surfaces in a studio to eliminate standing waves. Sure, residential spaces are not usually built to this convention, but some people (the OP, audiophiles, etc.) care as much about this as they do selecting the best equipment. As a tech you should at least be aware of the principles of how audio behaves in a room, and how to optimize it.

Rethinking bass traps:

http://www.soundcontrolroom.com/time-to-rethink-bass-traps.php

Absolutely agree. And all acoustic treatment should be given consideration based on appropriate analysis, e.g. diffusers.

Excuse my asking, but what does "frequency control" mean?

It might mean this:



I think a lot of people do not understand that trying to make sound (or anything else) natural artificially is an oxymoron.

It means managing specific frequencies that are overexpresed due to the shape of a specific room. The goal is to attenuate what is overexpessed so that what you hear is representative of the sound of the instrument. Lower frequencies are usually the most problematic because it can result in some notes on the piano really barking at you due to powerful standing waves being generated between certain walls. Corner traps are often effective at reducing this down to an acceptable level - although sometimes even more is needed. In the end, what you're trying to do is interfere with the specific dimension in the room that supports the problem frequencies.

So why has no one mentioned eigentones

Ian

I believe eigentones is another word for standing waves, correct?

Bass traps are most effective when they are floor to ceiling, and they are not nonsense.

The way I look at it is to picture a grand piano in a concert hall, the sound can radiate out towards the audience with effectively no interference. By the time it hits walls and bounces back it is already pretty attenuated (and the concert hall should be designed to deal with this anyway) so that there are minimal interference problems. The audience is mainly hearing the sound directly from the piano, not rebounding noise off the walls.

The same great power of bass that sends the notes to the back of the hall is a big problem in a small room. There is going to be tons of rebounding waves (particularly bass). The sound traps are not attenuating the sound waves that leave the piano, they are as their name implies trapping the ones that enter the corner and stopping excessive rebounds around the room. Thus the volume in front of the piano is still the same, and the bass is if anything improved as there are less interference patterns causing imbalances in the room.

Is it a huge difference? if you are right next to or plying the piano often no, but if you are trying to record it does matter.

Likewise with loudspeakers, room conditioning is as important if not more important than the speakers. If there are unfavorable room resonances and excess rebounding sound then even the best speakers are going to sound subpar.