Can we use the source in a dirty environment?
Usage in dirty environment should always be done with extreme care and at own risk. We
here by provide some suggestions:
•
Bring some foil or paper to place under the tripod and cables. And bring a plastic foil
or cloth to place over the equipment.
•
If there is dust floating in the test space or light moisture, there is no problem. This
should also not require any cleaning after a few hours of tests.
•
If you have trouble keeping you own clothes clean and dry because of dust, or water,
then you will need to protect the source with a enclosing thin plastic bag. (This is a
fairly normal procedure) This will take away 1 or 2 dB and limits the measurement time
to 1/3 of normal.
•
If you forget the source in a dusty environment: gently blow the dust from the speak-
ers with a nozzle from a compressor. Do not use a vacuum cleaner, because it can easi-
ly damage the source. Never use full power from the nozzle at short distance! You can
also use a dry cloth.
•
If you forget the source outside in the rain until it is soaked then let is dry at room
temperature. Do not place it against a heating. Drying will take two or three days. If
the amount of water was limited and reasonably clean, then the source may work well
again. Check this with a microphone near each individual speaker and compare the 3
rd
octave band or narrow band curves. Place the source on a soft surface with one speak-
er upwards, and place the microphone at the magnet. Run the source at a relatively
low level. Measure spectrum at a fixed amplifier setting with pink or white noise. Re-
peat this for all speakers and compare the differences to the allowable spread within
the ISO standard. The spread should be well below the standard.
What to do when one or two of the twelve speakers, or the housing, is damaged?
To prevent damage amplification, it is necessary necessary to stop using the source immedi-
ately when a strange sound or loss of power occurs. To prevent follow-up damage. If you sus-
pect that one or more speakers, or the housing, is broken, then only use a very low level until
repaired or good functioning of all 12 speakers is assured. So never use the source a high out-
put level if you suspect damage.
In doubt, to verify, place the source on a soft surface with one speaker upwards, and place the
microphone at the magnet. Run the source at a relatively low level. Measure spectrum at a
fixed amplifier setting with pink or white noise. Repeat this for all speakers and compare the
differences to the allowable spread within the ISO standard. The spread should be well below
the standard.
Never continue to use the source if in broken condition. It will aggravate the damage and in-
crease the repair costs significantly, and can cause exclusion from warranty.
When using an external input signal, could I damage the Qohm source or the Qam amplifier?
The Qam amplifier input will withstand any type of normal signal coming from any
measurement device or computer on the headphone outlet. The ouput of the Qam amplifier
will just try to follow the input signal up to ss 0.35V.
However, if mains power is somehow in contact with the input, or if the power output of the
amplifier, or of another amplifier is in contact with the input BNC, then this will damage the
amplfier.
The Qohm sound source will also withstand normal test signal at a reasonable level in combi-
nation with a Qam amplifier. Many signals can be applied at maximum level of a Qam amplifier
www.qsources.be
Ketelwinning 38 B-3290 Diest Belgium
Copyright Qsources BVBA
