My Hifi Configuration 2004.
Configuration 1998 - déc. 2003:
-
A sector filter.
- A CD reader NAD 512.
- L'Ampli 1998
décrit sur ce site.
- A pair of 4 ways speaker.
Sector filter.
This is:
Photo
I
conceived it to power up the whole systême (AMPLI CD) when I
power up the Tuner.
It is made by measuring the
sector current, then I compare it with a fixed voltage which I adjust
via a 10 turn potentiometer.
Filtration: I perform a
powerful filtration of the sector, followed by a small
additional
and independent filter for the CD and the tuner.
This
operation allows me to ameliorate a litle bit the reception of
the
tuner.
It is also one circumspection against noise
that it can injected into apparatuses, and perhaps also of the
parasitage between apparatus.
Description of the
4 ways speakers:
Photo
I have used this shape of speakers for a long time.
The bottom speaker, where I unfortunately do not have other photograph,
was constructed in 1998.
Every HPs comes from Jmlab/Focal (http://www.focal-jmlab.fr/).
Bass:
I decided in 1998 to add this box has reason of a mediocre quality of
bass which gave the 17cm 7V014DBL.
The
loudspeaker of serious is one 8V012DB (21cm) of mark Focal. It is cut
at 100Hz with a filter 12dB / octave. It is a double spool, impedance
is 4 ohm, this allows me to have more output in the bass. Used wood is
of MDF of 19mm.
The bass was symmetrical load, with laminar
blowhole on back side. The size of this blowhole was about
2cm*30cm of section and 40cm long. The volume of load had to be 10
liters for the rounded load, and 20 liters for the reflex load. The
loudspeaker is the 8V012DB (Jmlab / Focal). But this did not work. So I
transformed this charges into close load with back side decompression,
it is has say that I kept the blowhole, then I put the loudspeaker in
facade. I also have of fill the inside of glass wool, because this had
tendency seriously has resound.
Low bass,
medium, aigue:
Below,
there is a small speaker which brings 3 additional ways. The biggest
loudspeaker is a 7V014DBL (17cm). It is also a bass-reflex load, the
volume is 20 litre, and the whole is filtered between 100Hz and 400Hz.
This loudspeaker is above.
The medium is a 5V313 (13cm), a Focal
loudspeaker of the years 85/90 of middle of range. It is loaded by a
small closed volume of 1 litre. It is filtered between 400Hz and 3kHz.
This loudspeaker is at the bottom of the small surrounding wall.
The tweeter is T120TI (20mm), put directly in the volume of load of the
17cm, between the medium and of 17cm.
Listening / result:
The
21cm loudspeaker succeeds has marvel has make diminish the distorsion
which had the 7V014DBL, and therefore to ameliorate transparence at the
bottom of the spectre.
The medium was for me clear enough during years, and
I do not have complaint against the tweeter.
The
bass was of medium quality. I arrived to minimize the fall
of level at low frequency with the back decompression of the
close
load (the blowhole), but it was decreasing the impact of the drums and
other percussion which give between 50Hz and 100Hz.
Setup déc. 2003 - March, 2004:
- A sector filter.
- A CD reader NAD.
- Ampli
1998 represents on this site.
- A pair of 4 ways speaker with the new bass box.
Then
I decided to build again the box of 21cm absolutely. I chooses a
classic way: bass-reflex of 40 liters, with 2 vents of 7cm below and
upper the loudspeaker. This gives us the following photograph.
Photo
Of
course I always use the 8V012DB (21cm) in dual coil, with a 4 ohm
impedance. And then I innovate a bit in wood, little by hasars: I
chooses of the 3 coats batten of 27mm in fir. Good idea, because I
think it is more efficient than MDF. Without filter, this new box works
has marvel: flat answer, and answer impulsionnelle flawless. The bass
was here until 40Hz, the low knocked well, and sound was clear. I
acquired an interesting compromise finally.
But by
adding the filter at 100Hz and by using it in version 4 ways
as on
the photograph, I lost a lot in transitional answer! Therefore it is
disappointment, but also discovery of another reality: cut as low a box
of bass is not needed, at the risk of slaughtering transitional answer!
Then
it happend an accident: I destroy the 17cm by sending him a
direct
current of 2.5A. But I still need to listen music, and I don't
want to wait 3 weeks for new speaker. Then I move the frequency of
cutoff frequemcy of the 21cm from 100Hz to 400Hz. So the 21cm takes
care of the sound register of the 17cm besides its, and the
whole
sound band of the speaker was keep.
Listening/result:
I recover the impulse answer of bass box
alone. And even more, I discover that this 21cm is very distinctly
better than the 17cm in terms of clarity and transparence. On blow I
decide to stay with 3 ways, and I was waiting with impatience for the
6WM to see if he gets married well. This will be case.
Configuration May 2004:
- A sector filter.
- A CD reader NAD 512.
- Ampli
1998 for the preamplifier and a high-pass filter at
300Hz of 3rd order to erase the bass in the
amplifier class A 2004.
- Ampli
1998 for the amplifier of bass.
- Ampli
classe A 2004 A for the amplifier of medium and
aigues.
- A pair of 4 ways speaker constituted with the box bass
and the box medium-aigue.
At the beginning of 2004, I constructed the ampli class A, then I
compared with my previous ampli which is the ampli of 1998.
It appear hollow out that:
-
The ampli class A is distinctly better in the mediums aigues, but show
some weakness in the bass has reason of its output impedance. This
generates a deterioration of transient answer, thing which remains
really important. Another mailman degrades transitional answer, it is
for instance a frequency of too low cutoff frequency on the bass
loudspeaker. This will also be corrected in April, 2004.
- the
ampli 1998 has a flawless behaviour on the bass, and no loss
of
definition is easy to discern on this register. It is even better in
the bass that the ampli class A with its output
impedance extremely low. But it is less good in the mediums
aigue,
thing which appear distinctly on difficult passages of classical music.
From mid-May 2004, shape is the following:
-
I add a 3rd order high-pass filter at 300Hz on the card of
preamplifier of the ampli 1998. This active filter
allows to
avoid making saturate the ampli class A with the bass, which must be
deleted before arriving on the medium loudspeaker, so I
optimize
at best the low available power.
- I add output connector
cables CINCH / RCA on the ampli 1998 to link the ampli class A
on
the préampli of the ampli 1998.
- Therefore the volume, engraves, aigue, scales, selector of entrance
are those of the old ampli 1998.
- To put all chance on my side, I use new operational amplifier based
on AD825. It has a distorsion lower than 0.001 % at 20kHz!
- 3 ways speaker instead of 4 ways, and with a bass cutoff frequency
frequency increase from 80Hz to 300Hz.
- Abolition of a loudspeaker for high-bass.
Listening of May, 2004:
- The bass are flawless, finally an correct trtansient answer.
- The mediums are splendid, favour also to the purchase of the
loudspeaker AUDIOM 6WM.
- Aigues is good also.
- Definition is better, and "orchestral increase" are more clearly.
- Now, I wait for difference that bring the CD converter...
Configuration of July 2004:
It is especially performed by the addition of the separated CD
converter for which I wait to listen for 2 months.
The list of elements is therefore:
- A sector filter.
- A CD reader NAD 512.
- My CD
convertor
with the DF1706 + PCM1704.
- Ampli
1998 for the preamplifier and a high-pass filter at
300Hz of 3rd order to erase the bass in the
amplifier class A 2004.
- Ampli
1998 for the amplifier of bass.
- Ampli
classe A 2004 A for the amplifier of medium and
aigues.
- A pair of 4 ways speaker constituted with the box bass
and the box medium-aigue.
This update of end 2003 / beginning 2004 cost me in total 4617 Swiss
franc.
My
impression of listening is especially in Converter CD. I especially
earned mediums / aigues much more clearly and better define in
comparison with May. Copper improves distinctly by becoming distinctly
more true than before. I feel no regret for risks took, and results are
there.
evolution of my hi-fi chain - assemblage of the different
hi-fi elements
Créer le : 01 juin 2004.
Dernière modification le : 23 June 2007.