Acoustic properties of glass

[Vladimir Filevski]

It depends on the sort of glass and if it's had surface ion exchange a la Gorilla Glass.
Spoiler: glass science geek

Interesting! All glass sound-absorption data I can found are based on the float glass (commonly used in windows and doors). Some doors are made of (chemically or thermally) tempered glass, but I didn't find any sound-absorption coefficients for them - do you have any data?

 

[Vladimir Filevski]

I will publish a post asking for acoustic isolation perhaps, living on the town center has interesting sound issues.
My downstairs neighbor complaints about my piano, we complaint about the couple I mentioned, all of the building compliant about a student’s apartment (even the students complaints), and so forth…

Sound insulation is possible, but it is not easy to do and costs money. Advices on the forum may be good (I can throw a word or two, also), but for the best results - hire an expert.

 

[Miguelón]

Sound insulation is possible, but it is not easy to do and costs money. Advices on the forum may be good (I can throw a word or two, also), but for the best results - hire an expert.

Sorry, I forgot putting the smiley after my reply: is true what I said but I exaggerated a little bit. Diplomacy with the neighbor downstairs and patience with students and the couple overpopulating the planet is what we choose!

 

[Vladimir Filevski]

Nice that you resolved those problems by diplomacy (something which is not used enough in the World, I would say), but often those noise problems are big enough to demand different solution. For example, in two houses divided by common wall both neighbors were complaining they can hear clearly each other when speaking normally, even in the soft voice! Party with loud music was out of question. My sound insulation project brought additional 55 dB of attenuation, but it was relatively expensive. Other example - piano practicing problem demanded expensive "room-in-a-room" solution, etc.

 

[SIY]

do you have any data?

Only for ultrasonics, alas.

 

[Andysu]

ultrasonics glass directional sound

 

[egellings]

Of course glass thick as a brick will reflect everything. But glass so thick is very seldom used in windows, usually thickness is 3-6 mm for domestic/residential windows/doors and 8-12 mm for big shop-windows and big domestic glass walls. Thankfully, there are many tables with already measured acoustical properties (absorption coefficients, etc.) for many materials with different thickness.
Spoiler: Acoustics/Loudspeaker engineer here.

Thinner glass sheets could well flex a bit when impacted with sound waves, altering them ever so slightly.

 

[Vladimir Filevski]

Yes. that flexing is the cause of glass panel absorption of low frequency sound waves - it is the mechanism of panel membrane absorbers, which transforms some of the incoming sound energy into movement/heat.

Edit: membrane

 

[egellings]

Yes. that flexing is the cause of glass panel absorption of low frequency sound waves - it is the mechanism of panel absorbers, which transforms some of the incoming sound energy into movement/heat.

True.

 

[Sal1950]

It depends on the sort of glass and if it's had surface ion exchange a la Gorilla Glass.

Spoiler: glass science geek

windows glass reflection of conversation with laser microphone , so be careful what you say behind closed doors as there is always windows and that glass has ears listening in on it , maybe ?

Sound insulation is possible, but it is not easy to do and costs money.

This is how I dealt with my glass issues, 2" of Roxul Rockboard 60 acoustic insulation
Saves $ on heating and cooling too.
And I dont have Alexa, Google, or any other audio/video spies in my house either.

 

[egellings]

Also the mounting frame architecture affects the responses.

That's included in "tested in an identical way".

 

[Miguelón]

Finally the acoustic issue was not the glass apparently, once measured the room response the irregular distribution of the monitors was evident:

Left needed -4 dB bass tilt and -4 dB desktop mode (because of the adjacent table surely) and right one was corrected with -6 dB bass tilt due to the proximity of a corner (80 cm).

My ears went so much trough the bass, as Genelecs small monitors don’t go so low, but the measurement have the last word…

The glass was not very distinguishable from a wall, possibly because frame and some vertical brick made division between windows and door, and also side walls relatively close to speakers

I have some mid and mid-highs peaks but can live with them, that can be maybe the glass contribution …

Thank for all advices!