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Acoustic Componets & Acoustic Devices

Thehe GREWUS line-card of sounder products covers a wide range of technologies. From basic piezo plates to sophisticated micro SMT buzzers in electromagnetic version, designers and R&D engineers will find the best suited product. If it is about loudspeakers all types of diameters, housings and package sizes can be identified.

Moreover there are very specific products for certain applications, like high power sounders and beacons for applications in the fire and security industry, back-up alarms for buses and commercial vehicles, audio alerts for the automotive industry and of course many different buzzers for various applications in the household and white goods industry.

Just give us your inquiry. If it is about sound or alarm we are confident that we have a solution for you. A strong development team plus very close connections in the Asia market are means for a successful handling of your audible signals program.

Acoustic Componets & Acoustic Devices  - Products by Grewus

Sound Information
1. What is the Conversion of Sound Pressure Level SPL to different distances [r] ?
CloseConversion of Sound Pressure Level SPL to different distances [r]

The sound pressure level corresponds to distance as 1/r. The formula for calculating two sound levels in a distance is defined as follows:

Sound Level Formula

This means that, when distance is doubled the sound is decreased by 6dB accordingly. The sound difference between 10 cm and 1m is 20dB.
2. Is it correct, that an adjustment of volume by 6dB corresponds to the volume being doubled or halved respectively ?
Close Yes, this is correct. When the distance to a sound source is halved or doubled resp. the sound level changes by 6dB. This statement is not very relevant for humans, as our auditory system is not able to evaluate the technical logarithmic measure of the sound pressure level in quantified terms, that is, psycho-acoustically.
3. How do I properly select the appropriate signaling device for my application ?
Close As a rule one should first of all examine the available environment and make up a list of framework conditions. What are the requirements concerning mechanical dimensions, controlling (actuating) conditions, what is to be reproduced?

If a linear frequency response is required, as for speech or music reproduction, one should decide to use a loudspeaker.

If higher frequencies shall be reproduced it is recommended to employ a piezo signal generator. As this type of signaling device is generally flatter than e.g. a magnetic buzzer, piezo buzzers find multiple uses in flat applications with little space upwards. In addition piezo signal generators tend to use less power which for instance is desired in battery applications.

If deeper, "saturated" or full sound shall be reproduced, a magnetic buzzer is a good choice to be used. In general, this type of signal generators on the whole offer a more "pleasant" sound, but need a little more power which in some applications is not desired.
4. Units used in acoustics (dBa, dB, Dbc, Sone)
Close As a general rule, noise or sound level is measured in dBA. The letter "A","B" or "C" after the dB denotes that the sound level has been measured by using a filter. "A" refers to a filter that takes the audibility curve of the human ear into consideration. The A-weighting curve (expressed in db(A)) on the other hand is relatively linear and is generally used for higher sound level volumes.

Sound Level Volumes

Apart from the sound pressure level SPL there are the units “Sone” and “Phon”. “Sone“ is understood as the subjectively perceived loudness, whereas „phon“ is a unit of loudness level for pure tones. Per definition 1 Sone is the same as the loudness of a signal at 40 phon or equivalent to the loudness level of a 1000 Hz tone at 40 dB SPL. A sound given as 60 phons means it is as loud as a 60 dB, 1kH tone. While the sound pressure level can be measured directly, loudness cannot be measured.

The following table gives an approximate perception of the interrelations.

approximate perception of the interrelations
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