The is considerable scope for tuning loudspeaker; in the following we'll discuss
the different methods.
It is, therefore, advisable to exchange light cabinet material for a more
heavy one. Chipboard and MDF (medium density fibre particle board) are quite
heavy. There is no need to change the cabinet material when it's already heavy
enough. You'll find out quickly whether the cabinet material is too light
when entering cabinet volume and wood gauge into our Volume
Perfectionist use sandwich boards where the cavities are filled with sand.
The trickling sand ensures that the vibration is absorbed.
But it does make sense to do it the other way around, especially when a subwoofer
is going to be added. The loudspeaker doesn't need to go that low anymore,
since this has become the job of the subwoofer. When the bass reflex port
has been closed, there will be less but clean bass.
A word of advice with regard to bass reflex tuning: the longer the bass reflex
tube the lower the tube's resonance and the less boomy the sound. If the speaker
lacks bass then a shortened bass reflex tube might help to subjectively increase
the bass perception. In this case the resonance is shifted to higher frequencies,
the bass becomes more distinct.
Those who like to listen to music at a high volume have probably noticed that
their speakers cannot handle it. If the bass driver is the bottleneck then
there is a solution.
If the frequency range is restricted to higher frequencies by adding a 330
μF capacitor (for 4 Ohm speakers) or 150 μF (for 8 Ohm speakers), a large
part of energy and mechanical movement is kept away from the driver.
If the capacitor is added between amp and speaker the capacitor should be
of high quality; At least 22 μF (47 μF for 8 Ohm speakers) should be equipped
with MKP capacitors, since this capacitor represents the bottleneck for the
Another solution would be to add the capacitor to the bass driver section
only, to make sure that higher frequencies are not affected.
In case that the crossover's design is correct and the sound is still not
satisfactory, tuning won't help.
You should only improve on something that is already good. Crossover tuning
changes the sound just marginally.
Which components produce which improvement?
How resistors affect the sound quality is a controversial subject, we are not
a judge of that. However, we recommend a blind test whereby neither the demonstrator
nor the listener knows which resistor is being used at the moment. To be frank,
we still have to find a sound difference.
Electrolytic capacitors are more lossy than foil capacitors, it makes sense
to exchange them. There is an exception: an impedance correction where the
RLC element is in parallel to the speaker terminals doesn't require a top
notch quality, expensive component.
During listening tests many of our customers noticed a considerable sound
improvement when a cheap MKT capacitor was replaced by MKP capacitor, especially
with regard to mid and high frequencies.
Tin foil capacitors show a smaller microphonics effect, i.e. their heavy
electrodes don't have the tendency to vibration. This lack of vibration prevents
the capacitor from taking on a life of its own. This would certainly affect
the sound when a voltage is applied to capacitor.
Mundorf Supreme CAPS (and comparable capacitors by other manufacturers like
IT and Jensen) as well as Silver Oil capacitors are completing the range of
Air core coils show the lowest distortion. Coils with a core need to reset
the magnetic core. This causes losses and distortion (non-harmonic distortion,
A disadvantage of air core coils is that, at the same DC resistance, they
are often bigger than core coils.
Copper foil coils (cfc coils) show a considerably low microphonics effect
Especially with regard to crossover tuning the professional loudspeaker designers
believe that less has to be done than expected by the hobbyist. Many top designer
are of the opinion that MKP capacitors and air core coils are sufficient even
in top speakers.