I-33 Owners Manual V1.1 3 March, 2014 98-091-002
VAF I-33
Notes on Loudspeaker Usage
There are some matters that should be considered when you use your loudspeakers, both or the irst time and every time, to ensure their
best per ormance. This is true o all high quality loudspeakers regardless o the manu acturer.
Power Handling and Amplifier Selection
'Power Handling' is a much discussed but little understood subject. There are actually 2 issues:
• how much power the loudspeakers can take be ore they start to lose quality and produce distorted sound
• How much power they can take be ore they are permanently damaged.
The irst is a unction o the driver and enclosure design, and the spectral and dynamic content o the music, and is usually limited by the
distance that the driver cones can linearly travel. Exceeding this level, particularly during heavy bass passages, results in an obvious
degradation o sound quality. Many loudspeakers will brie ly exceed their linear travel during loud passages o music and, provided that it
occurs in requently and is not excessive, will not unduly impede the overall sound quality.
I the speakers are driven with even more power, the sound will deteriorate urther until the point is reached where physical damage occurs.
This is usually the result o the driver voice coils getting so hot that either the glue holding them together melts, or the wire itsel burns up
(like use wire). The driver will stop working or will produce a distorted sound with audible scraping and scratching sounds. This is bad
news and the driver then needs repair or replacement.
Surprisingly, damage is more common with low powered ampli iers than with high-powered ones. This is because low powered ampli iers
are more likely to be overdriven - this results in a major change in the content o the music signals, which places great stress on drivers. At
the same volume high-powered ampli iers are less likely to 'run out o power' and send distorted signals into the loudspeakers.
The power handling issue is urther complicated by the act that the 'X Watts RMS into 8 ohms' igure most o ten quoted in ampli ier
speci ications gives very little in ormation about the way the ampli ier will actually deliver power into real loudspeakers on real music
signals. It also gives no indication o how the ampli ier behaves when overdriven. Many low powered 'Audiophile' ampli iers, or instance,
will o ten play louder be ore producing audible distortion than some mass market ampli iers o 4 times the rated power output!
It is there ore almost meaningless to rate a loudspeaker's power handling as a single number. Despite many requests or just such a
number, we pre er to state the broad range o ampli ier power we believe has the best chance o meeting most peoples needs. This range is:
VAF I-33 20 - 150 Watts RMS (Dolby Digital / DTS)
VAF I-33 20 - 150 Watts RMS (Stereo Music Sources)
Be aware that overdriving ANY ampli ier will risk damage to the speakers. I the sound you are hearing is distorted or showing signs o
ampli ier clipping TURN DOWN the level. Even a small reduction in the volume control setting may save your speakers.
Most ampli iers deliver their maximum power long be ore the volume control is turned all the way around. Many are set up or maximum
power with the control set to between 11o'clock and 1o'clock. This will sometimes vary rom input to input (e.g. the CD player may play at a
higher level than the FM Tuner).
Be aware also that applying Bass or Treble boost by using the tone controls or any equalisation control o your ampli ier has the same e ect
as turning the volume control up. The maximum volume control setting should be reduced i using equalisation.
Most Ampli iers deliver maximum
Power with the Volume control
set between these points
