Piano World Home Page Forums Our Most Popular Forums Piano Forum Yamaha C7 volume and tone control with foam

I'm interested to see if others have worked with foam baffles for tone control. My 1990 Yamaha C7 has always been loud and bright in my large 30' x15' triangular, carpeted room. The action has been even, and it holds its tune well. I had a concert technician do a two day 'concert prep' involving hammer sanding and filing, complete regulation, tuning, voicing and re-tuning.
After this the speed and repetition was improved, the tone slightly softened, and dynamic range improved. It still was a little brighter and louder than I would choose.
I made a string cover, which had minimal effect. I then got a 4" foam bed and cut baffles to fit to underside compartments. This seemed to have a slight benefit.
I would be interested in any experience in controlling tone and volume with acoustic materials.
Thanks for any input. Neil Adler

Putting material under the soundboard can lead to a humidity imbalance between the top and the bottom of the soundboard, which can damage the soundboard.

Further voicing is a better idea.

Great advice. I had a friend who put an upholstered ottoman under her grand piano to great effect.

I hadn't considered the humidity effect. I live in California, which is usually an acceptable 20-40%. Would the wool string cover, or even lid closed position cause some humidity retention?

Just thinking... Doesn't a Damp Chaser lead to a similar humidity imbalance between the top and the bottom of the soundboard? Wouldn't this also lead to damage?

In all the years I have been reading on PW, the question of benefits or disadvantages of a Dampp Chaser have never been resolved. You will hear from those who swear by them and from those who swear at them. Take your pick.

Regards,

Back to the OP... So, you mentioned that the room is carpeted, what about adding window dressings? Lumpy (pillowy/fabric-y) furniture?

I too have an older Yamaha C7 (circa 1978) and I love it, and then some! It is not too loud or boisterous at all. My music room is 20'X20' with 10' ceilings. Maybe the 10 foot ceilings make the difference.

Anyway, I have never thought the piano was too loud. The tone is rich, with a combination of mellow and bright timber. The upper treble is distinctive and produces that bright "pop" that you would expect from a semi-concert grand, and the low bass is superb.

I have a commercial grade carpet on the concrete floor of my music room, and that may help with the volume as well. I've never felt the need to tone it down or reduce the loudness or volume. It could use a hammer reshaping and voicing now, because the hammers have some shallow string groves, and I put everyone of them there... so, the string groves in the hammers are more of a trophy than a tribulation.

My C7 has some wear, but still has a lot of life left in it, as far as I'm concerned.

Sounds like you've gotten some great advice here in regards to harnessing the overballance of sound and volume with your C7.

Good luck!

Rick

I also live in California, 10 miles from the coast, and have had a wool string cover on my piano for 30 years. I keep the lid down. No humidity problems at all. (So far)

It can just as easily lead to no problems at all. If you have a room with widely cycling humidity, you can just have some vent holes in your foam. The foam doesn't have to be totally sealed against the frame to effective. I have foam in one of my pianos and it's a lot more effective than voicing ever was - best of all, it didn't change the tone of my piano like voicing does, only reduced the volume. Sometimes people kill an idea because they project dire outcomes that never actually come to fruition, or can easily be avoided.

Nadlerus: give the foam a go. It's a lot cheaper and easier than voicing. If you're worried about humidity (which I really doubt you need to), just drill a couple of holes into each foam block. I think you'll be happier with the outcome than trying to voice your piano to a lower dynamic level.

I wonder if you could put some attractive hassoks under the piano and get the same effect as the foam?

Yamahas of that era are mostly bright pianos, especially when compared with the latter-day CX series. It's inherent in the hammers they used; not sure how much can be done. That's probably why your tech's work only lasted so long. A new set of hammers might be in order.

Hi Neil,

How long have you owned your C7? If you bought it loud and bright in the first place, you can only do so much with voicing and string covers. Modifications to the piano itself could start to get expensive. If it were me, I’d be checking out acoustic panels for the room or just better sound proofing. I’d always play it with the lid down. That’s the cool thing about a C7. You can easily just play softer.

I have no idea how expensive it is to just put in new hammers.

Some of us don't think that hassocks of any design are attractive and don't belong under a piano!

Just sayin', ya know?

I was just thinking that a soft, pillow-top hassock or other kind of low, cloth furniture item would look better than a bunch of generic foam or bean bag chairs etc. (all of which get recommended here)...

I know I’ll get in trouble with other forum members for asking this but why would you, Neil, buy a 1990 C7 if you didn’t want loud and rather bright?

Yes, Thanks for all input. Very interesting.
When I traded by 6' Kawai for this C7, ten years ago, I was happy with the presence, projection and control.
This jazz pianist didn't change furnishings etc, and just kept it tuned, every few years. I let the regulation go off, and didn't do any voicing other that brushing hammers for recording sessions. I guess I am playing more romantic music these days, and working to control a cantabile legato. The concert prep work helped most with action, and a little less with tone.
So I'm back to using the foam baffles, and string cover, with a nice balanced tone, not nearly so muffled as entirely closing the lid. I placed humidity meters under and over to watch and compare, but so far, both stable at a slightly muggy, smoky California bay area 45%.
Likely I'll experiment by removing one or other for recordings. These things are as much perceptual as real and change over time.
Neil Adler

Thanks for explaining that. It helps me understand the dilemma.

Perhaps its the triangular shaped room.? 🤔 Could the sound be bouncing from wall to wall. Perhaps adding large tapestries on the walls forming the angle.(or even pretty quilts .You could experiment with blankets.
Another approach would be moving the piano from the
position to another position in the room.

When we voice pianos, we usually do close to the minimum to make the piano even. More can be done, but it needs to be done to the customer's preference. Also, it can be arduous work, so while much can be done in one day, additional time can be necessary to make a bigger change in the piano's overall character.