Sound deadening - results and DIY or A&P?

[Flyler]

I'm looking at purchasing a Mooney, hoping for an m20F model but also looking at the m20C/E models.  Really, I just need to get my butt into the back seat of one to see just how tiny it is

At any rate, whatever I buy will probably be due for an interior update and the top of my list is sound deadening.  Has anyone gone down this path?  I've done vehicles before and was always very happy with the results.  It seems that interior work can be done by the owner/operator and doesn't require an A&P, but I have no direct experience.  Perhaps my assumption is wrong?  Would I be able to add foam/foil sound deading myself and have an A&P sign off on the weight addition?

Interested to hear from anyone that has done this- was it worth the work?

[Hank]

A good headset kills lots of noise, takes little effort and no W&B issues.

My wife didn't want an in-ear headset, so I bought a set of yellow Halos (mine are black) and told her if she didn't like them that I could sell them for what I paid. She used them in a 30-minute "test flight" and told me not to sell them. 

Halos work as well as active noise canceling headsets for a third the price, and a wifi adapter is available too.

[Flyler]

5 minutes ago, Hank said:

A good headset kills lots of noise, takes little effort and no W&B issues.

My wife didn't want an in-ear headset, so I bought a set of yellow Halos (mine are black) and told her if she didn't like them that I could sell them for what I paid. She used them in a 30-minute "test flight" and told me not to sell them. 

Halos work as well as active noise canceling headsets for a third the price, and a wifi adapter is available too.

Thanks Hank, I agree whole heartedly.  I have a set of Bose noise cancelling and a Lightspeed noise cancelling for the wife as well.  We are planning some trips with the pup, and she has muttmuffs  

I've just always found that a more quiet interior space adds a lot to the "luxury" of a vehicle.  Who knows, I might decide it was a silly thought later on...

[McMooney]

yeah, just buy a good noise cancelling headset,  even with good insulation and thicker windows, it's still not quiet.

running at something like 2000 rpm /20in is talkable however.

also the c/e aren't overly small in the back, Once the front seats are pulled into flying position, more room than economy plus.

the seats fully back and theres only like 4 inches between the backseat and the front

 

also sound deadening material as in a car, is HEAVY, something to be avoided in a plane

Edited March 21 by McMooney

[Shadrach]

15 minutes ago, Flyler said:

Thanks Hank, I agree whole heartedly.  I have a set of Bose noise cancelling and a Lightspeed noise cancelling for the wife as well.  We are planning some trips with the pup, and she has muttmuffs  

I've just always found that a more quiet interior space adds a lot to the "luxury" of a vehicle.  Who knows, I might decide it was a silly thought later on...

I covered every part of the interior walls with .5” super sound proofing from Spruce. I also made ceiling panels out of it and covered them in same lightweight ultrasuede that I covered the plastic panels with. I don’t know that it made a huge difference in noise reduction. It did eliminate almost all rattle and vibration from the interior.  The interior now has a much more refined and warmer “feel” as all surfaces are upholstered. More importantly, it really evened out interior temperatures in the winter. My bird has a blast furnace of a heater, but before insulating it was tough to keep everyone comfortable in cold temps. You could keep the back seaters warm but at the expense of cooking those up front. It’s much better now, not perfect but if people wear layers, we can keep everyone comfy even at single digit OATs.

[Utah20Gflyer]

I suggest you run the prop at the lowest RPM that is reasonable when in cruise.  There is a big difference in noise between 2700 rpm and 2300rpm.  Also you should save gas and some wear on the engine.   Extra sound proofing is only going to make a marginal difference.  IE you can probably realize a bigger drop in decibels by reducing prop rpm another 100 rpm than all the sound proofing you could stuff in a Mooney. 

[LANCECASPER]

1 hour ago, Flyler said:

I'm looking at purchasing a Mooney, hoping for an m20F model but also looking at the m20C/E models.  Really, I just need to get my butt into the back seat of one to see just how tiny it is

At any rate, whatever I buy will probably be due for an interior update and the top of my list is sound deadening.  Has anyone gone down this path?  I've done vehicles before and was always very happy with the results.  It seems that interior work can be done by the owner/operator and doesn't require an A&P, but I have no direct experience.  Perhaps my assumption is wrong?  Would I be able to add foam/foil sound deading myself and have an A&P sign off on the weight addition?

Interested to hear from anyone that has done this- was it worth the work?

I've used the SoundEx insulation product on two Mooneys that I owned while the interiors were out. When the first one was finished I was disappointed since it seemed to make almost no difference in noise levels. However in the first year of ownership I noticed that it stayed cooler in the summer and warmer in the winter. I did Soundex on the second interior just for the temperature. I agree that headsets make the biggest difference but careful attention to the door and baggage seals will lower the noise considerably as well.

[Flyler]

Thank you all for your responses.  Everything makes sense.  I agree 100% with just throttling down a little bit too.  It also fits my general vehicle purchasing mentality- buy the hotrod and don't go hotrodding it around all day... keep that power on tap for when you want it and make the motor last

[Brian E.]

On 3/21/2024 at 7:00 PM, LANCECASPER said:

I've used the SoundEx insulation product on two Mooneys that I owned while the interiors were out. When the first one was finished I was disappointed since it seemed to make almost no difference in noise levels. However in the first year of ownership I noticed that it stayed cooler in the summer and warmer in the winter. I did Soundex on the second interior just for the temperature. I agree that headsets make the biggest difference but careful attention to the door and baggage seals will lower the noise considerably as well.

Lance - I've been look at SoundEx for cutting down drafts in the box on my Moonship.  Did you use the 1/2" or 3/4" version.  In general for a mid or short body Mooney, how many 4x3 rolls do you recommend?

[LANCECASPER]

26 minutes ago, Brian E. said:

Lance - I've been look at SoundEx for cutting down drafts in the box on my Moonship.  Did you use the 1/2" or 3/4" version.  In general for a mid or short body Mooney, how many 4x3 rolls do you recommend?

I did two long bodies, both were M20M (serial number 0007 and 0150), neither of which had the later fiberglass interiors. I did own a Bravo with the fiberglass interior (serial number 0209)and don't think I would have seen much difference in sound and temperature . . .  however if I spent all of the time to take the interior out and had the time I would probably still do it for even a marginal improvement.

The Royalite interiors really benefit from this the most. It doesn't really lower the sound but muffles it, if that makes sense. The Royalite plastic panels "rattle" and this improves that a lot.  The biggest benefit is it moderates outsides temperatures. Any Mooney owner with Royalite panels that is going through an interior upgrade is foolish not to upgrade to Soundex while they are at it. You can do it while they shop is working in the panels and you don't lose any time.

I bought 4 of the 3/4" 36X48 sheets from AircraftSpruce and had some left over. With my discount these were each $116 back in 2016. With better planning I could have done it in three sheets, and I would do that now since they presently list for $238.75 each. But since I was investing a lot of time in it I didn't want to run out.

On a C if you are careful in planning, you could make two sheets work. One thing I can recommend for sure is using an electric knife to cut it. I went to Walmart and bought a $20 knife that you would use to carve a turkey. It saved many hours.  Also I bought some sheets of poster board and while was in the airplane I would cut patterns for what I needed to cut for the Soundex. Getting all of the patterns done ahead of time would save material for sure.

[Brian E.]

15 minutes ago, LANCECASPER said:

I did two long bodies, ...................Also I bought some sheets of poster board and while was in the airplane I would cut patterns for what I needed to cut for the Soundex. Getting all of the patterns done ahead of time would save material for sure.

Awesome summary--thank you so much.

[Fly Boomer]

12 hours ago, LANCECASPER said:

I bought 4 of the 3/4" 36X48 sheets from AircraftSpruce and had some left over. With my discount these were each $116 back in 2016. With better planning I could have done it in three sheets, and I would do that now since they presently list for $238.75 each. But since I was investing a lot of time in it I didn't want to run out.

On a C if you are careful in planning, you could make two sheets work.

From the SoundEx website, for M20 thru M20E, it looks like their kit includes 5x 1-inch, 1x quarter-inch, and 1x eighth-inch.  On the side walls, did you cut the pieces such that they would be slightly compressed between the airframe tubes?

[LANCECASPER]

8 hours ago, Fly Boomer said:

From the SoundEx website, for M20 thru M20E, it looks like their kit includes 5x 1-inch, 1x quarter-inch, and 1x eighth-inch.  On the side walls, did you cut the pieces such that they would be slightly compressed between the airframe tubes?

They didn't have a kit for the M20M, but even if they had, I wouldn't have bought the "kit" from SoundEx since they ask way too much for what you get.  The 3/4" material I bought from Aircraft Spruce works in every area. It can be cut slightly larger, maybe 1/4" larger than the opening, and be press-fitted in between the tubes. I used small pieces of the tape on most of the pieces to secure them, but to still allow them to be removed for inspections.