What do you do on a cold, wet, cloudy and dark
early March weekend? Make better TV sound! Definitely something you
don't do during summer time. I love my 42" Panasonic TX-P42G10E plasma TV!
Unfortunately Panasonic has seized producing plasma screens. I still
have to see the cheaper LED screens display better colour fidelity. 42"
is the right size for our small living room and viewing distance despite
almost considered small by today's standard of 50-65" screens.
Flat screens are trouble when it comes to good sound. As you may have
noticed, we can't fool acoustics - at least not much. Due to limited
space, producers have to insert tiny speaker drivers into almost no space.
Being already more than 6 years old, the Panasonic here is not as skinny
as more recent TVs and there are some space for two
down-firing rectangular drivers of decent size, but nevertheless,
what we hear is reflected midrange and not much more.
First thing to do in removing the rear cover and take the speaker wires
to a switch delivering either signal to in-built speakers or external
speakers. This way we have both options and it's sooo good
demonstrating to visitors what crappy sound they have from their flat
Now, if you don't want to fool around with wires and solder irons, buy a
sound-bar to install below the screen. But here we want something more,
in fact much more - and for less! Two decent 4" drivers and a small
dome comes for almost nothing and the cost of crossover components can be
modest too. The SBA alu drivers eventually use here are around 30 EUR/ea.
I had the Monacor
DT25-N domes on the
shelf from former (tube-) TV sound systems and they do very well. The
SBA is 4 Ohms
SBA12PAC25-4. Actually the Monacor dome is too expensive. Vifa has a
similar type at half price,
EUR, but probably needs a modified crossover.
I started out with the ScanSpeak
you want it all very simple, these drivers are doing really well and
deliver a decent treble, but I felt that given the space available, I could
get even more from my 2.5 liter net volume. I could have used the ScanSpeak
12W Discovery as well, but they were not at hand.
PS: No speaker kit will be available for this project and no further
instructions will given.
Having installed the switch on the rear panel to allow external speakers
I started out using my
speakers. Comparing to the in-built speakers even impressed my wife! But
the 12Ws are above size and budget for this project - albeit highly
recommended if your budget allows.
As said, I started out with the Discovery 10F drivers. Above and below
some images from the workshop.
I had a pair of these SBA 4" SB12PAC25-4 drivers:
Specs for tweeter
The shape of the cabinet had to follow the shape of the TV stand.
Cabs glued and first coat of lacquer. I also made holes for ports, Ø30 x
Tiny crossovers from leftovers and the final drivers. Right: Typical
frequency response from flat screen (taken from the web).
Schematics and frequency response, the latter not really too bad from a
quick'n dirty set-up.
Listening to the two finished speakers from my workshop system really
suggest another small mini in a more optimised cabinet and even better
crossover components. This 4" alu driver deliver a great mid/upper-mid
and transparency as good as it gets. Seriously!
Cabs will be held in place by three 12 mm alu tubes drilled into the
stand and cabinets.
Cabs were damped with 8 mm felt material. To the right the finished
Crossover is below the tweeter as far away from the SBA magnet as
What you can hear from the above compared to the in-built speakers is
The Panasonic manage 10 wpc output, more than enough for the 4 Ohms
It's been 6 years since I bought the TV... better late than never.