Ultrafonic Blog
76 FOLLOWERS
A blog for acoustics and soundproofing, dealing with DIY acoustics and topics of interest to the acoustics community and those who need good acoustics. Stay tuned to get updates.
Ultrafonic - Soundproofing and Acoustics
3y ago
Answer: The smallest amount that makes the room echo not a problem. (Also, the lowest cost, easiest to install and most practical).
Small office with too much echo
The common misconception;
If we have two types of absorbers, each with a different NRC (Noise Reduction Coefficient), then we need more of the one with the lower NRC to achieve the same total absorption.
Example;
Absorber 1 – NRC 0.6
Absorber 2 – NRC 0.9
You might think that since absorber 2 is has an NRC 1.5 times that of absorber 1, you would need 1.5 times as many square metres of absorber 1 to get the same effect – but this is ..read more
Ultrafonic Blog
3y ago
When working from home, these are the key elements to making your phone calls, online calls and online meetings sound good….
Microphone location
Backgound noise
Room sound
Equipment setup
Microphone location - The mic. should be quite close to your mouth. This makes what you say louder than other sounds. In other words, background noise and echo from the room are quieter compared to your own speech. You should hear the benefits of this in your own headphones but the listener(s) at the other end will certainly benefit. Keeping the mic. close can be as simple as using a headset with inbuilt ..read more
Ultrafonic Blog
5y ago
It seems to be common to cover walls, or large parts of them, in relatively thin absorption (9 to 15mm thick). This may be because it is heavily advertised, seems to be lower cost or because it means less paintwork needs to be done. More than likely though, it is done out of ignorance. The thought that more is better is a fallacy for two reasons;
It is not a linear addition. If reducing the reverberation time on the room to half it’s current level requires 5 square metres (for example), the next 5 square metres also halves modified level i.e. the first five square metres goes from 100% to 50 ..read more
Ultrafonic Blog
5y ago
https://didgeproject.com/therapeutics/doctors-now-prescribing-music-for-heart-ailments-brain-dysfunction-learning-disabilities-depression-ptsd-alzheimers-and-more/?fbclid=IwAR0X8he4OUZPg6zacIflFPPsTlV3VONEHh91G--YA4TeEQT9YiC1JkgXV1M ..read more
Ultrafonic Blog
5y ago
What is the evidence on the role of the arts in improving health and well-being? A scoping review (2019 ..read more
Ultrafonic Blog
5y ago
This restaurant tried the cheap route like we see all the time, and if FAILED… like we see all the time. Some unqualified person ran a phone app made by a supplier and guess what, it told them to put thousands of dollars worth of their product on the walls and ceiling. Needless to say, it may have looked OK but it did not make the acoustics suitable for a restaurant. As a side note, it didn’t even have any fire hazard safety certification as required by the NCC.
They asked us to give our advice, so we did the proper calculations and supplied what they needed to get the restaurant sounding as ..read more
Ultrafonic Blog
5y ago
Noise management for events and venues
Usually, a noise limit is set, and if you go above it, penalties apply.
It is set at a fixed position in the venue and calibrated to a lower noise level at the receiving point (usually neighbour). For example, if anything over 105 dB LAeq inside the venue causes excessive noise at a neighbouring receiver, the limit will be set at 105. It is usually measured at 3m from the PA system.
This is very common and suffers a multitude of problems...
Limiters are installed in the venue to prevent going over the noise limit. They either, turn the power to the PA sys ..read more
Ultrafonic Blog
5y ago
These curves describe acceptable background noise in rooms. They are empirically derived to approximate human hearing sensitivity (which varies with frequency) and represent annoyance or interference with the activity in the room e.g. hearing on the telephone in an office or call centre.
Most importantly, the curves rise at lower frequencies because our hearing is less sensitive to low frequencies and increasingly so at overall lower levels. So if the background noise were louder at low frequency, we may perceive it as at a similar level to the overall. In other words, in an office we can acce ..read more
Ultrafonic - Soundproofing and Acoustics
5y ago
RT60 is a single figure that may be OK to describe the required performance of an office or a worshop, but it is not sufficient to describe the acoustic performance of a specialised room. Such rooms include classrooms, multi purpose halls, auditoriums, music teaching rooms etc.
RT60 is calculated by averaging the reverberation time at 250, 500, 1000 and 2000Hz. For example, if the reverberations time were 0.9s at 250Hz, 0.7s at 500Hz, .06s at 1000Hz ..read more
Ultrafonic Blog
5y ago
Isolating a floor/ceiling – a real case
One of the first steps in our studio build is working out how to treat the floor of the office, which is directly above the studio. The floor is yellow tongue and clip down flooring on 90mm steel channel.
The options are;
Put insulation under the floor and plasterboard on the underside of the steel channel. Then hang isolators and put two layers of plasterboard and Green Glue with some more insulation above it (System 1 below), or;
Add plasterboard directly under the existing yellow tongue with Green Glue and then do the same as before - hang is ..read more