advice for making an informed1828 .pdf
Original filename: advice for making an informed1828.pdf
This PDF 1.4 document has been generated by / iTextSharp™ 5.4.1 ©2000-2012 1T3XT BVBA (AGPL-version), and has been sent on pdf-archive.com on 01/12/2013 at 15:01, from IP address 23.105.x.x.
The current document download page has been viewed 563 times.
File size: 4 KB (2 pages).
Privacy: public file
Download original PDF file
advice for making an informed
Wireless loudspeaker producers typically publish the frequency response of their solutions which,
sadly, won't always show you a great deal concerning the sound quality. You may possibly not
completely understand exactly how the frequency response is measured. I'm going to clarify what
exactly this phrase means. I hope you'll be able to make a more well informed buying decision.
A set of cordless loudspeakers are transmit and the reproduce an audio signal which is within the
frequency response range. This range is specified by showing 2 frequencies: a lower and upper
frequency. To give an example, the lower frequency might be 20 Hz and the higher frequency 20
kHz. From this specification it seems like the cordless speakers can work as a set of HIFI
speakers. It might seem the larger the frequency response the higher quality the cordless
loudspeakers. That, however, may not always be. You have to glance at the specifications far
more closely in order to adequately interpret these. A large frequency response doesn't mean the
cordless speakers have excellent audio quality. For instance a set of wireless loudspeakers which
has a frequency response between 30 Hz and 15 kHz might sound better than a different set
having a response between 10 Hz and 30 kHz. Furthermore, each maker, it seems, uses a
different technique of specifying the minimum and maximum frequency of their cordless speakers.
The most frequently used technique is to describe the frequency response as the frequency range
within which the wireless loudspeakers will have fairly constant sound pressure level with a
maximum drop of 3 decibel (dB). Typically the decline in sound pressure level is highest at the
lower and upper frequency.
Nevertheless, numerous manufacturers overlook this convention. They push the lower frequency
and upper frequency to where the wireless loudspeakers barely offer any kind of sound response.
Moreover, these numbers tell practically nothing about precisely how linear the wireless speakers
are working inside this range. A full frequency response graph, however, will show if there are any
kind of peaks and valleys and also show how the frequency response is to be understood. Peaks
as well as valleys might cause colorization of the audio. Preferably the sound pressure level of the
cordless loudspeakers should be linear throughout the entire operating range. To better
comprehend the frequency response behavior of a specific type, you should make an effort to
determine under which conditions the response was calculated. You might find this info in the
data sheet of the wireless loudspeakers. However, most producers are not going to publish those
in which case you may need to contact the maker directly. One condition which may effect the
frequency response is the impedance of the speaker driver built into the cordless loudspeakers.
Normal speaker driver impedances range between 2 to 16 Ohms. The lower the speaker driver
impedance the greater the strain for the internal amp.
Mainly current wireless speakers which use digital or "Class-D" amps will show changes in the
frequency response with different driver loads. The primary reason is the fact that Class-D amps
employ switching FETs as the power phase which create a lot of switching components. These
components are eliminated with a filter that is part of the internal speaker amplifier. Then again,
the frequency response of the amplifier now varies according to the loudspeaker driver load
considering that the behavior of this lowpass filter is affected by the load impedance. Normally the
lower the loudspeaker driver load impedance the lower the upper cut-off frequency of the amp A
number of the most recent digital amplifiers feed back the music signal following the lowpass filter
to be able to compensate for this drawback and to make the frequency response of the amp
independent of the connected driver load. However, if the amplifier is not designed properly, this
type of feedback may cause instability and bring about loud noise being generated by the amp if
specific speakers (you will find further resources on the subject of wireless rock speakers at
amphony.com/products/wireless-speaker.htm ) are connected. Different amplifiers utilize
transformers and provide outputs for several speaker loads. Aside from enhancing the frequency
response of the amplifier, this technique typically also enhances the amplifier power efficiency.