Altair FA-524, Руководство пользователя

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DELAY CARD EFFECT, DEPENDING ON DS1 SWITCH
DS1 1 2 3 4 5 6 7 8
2ms 0-250µs 250-500µs 500-750µs 750-1000µs 1000-1250µs 1250-1500µs 1500-1750µs 1750-2000µs
500µs 0-62,5µs 62,5-125µs 125-187,5µs 187,5-250µs 250-312,5µs 312,5-375µs 375-437,5µs 437,5-500µs
The theoretical adjustment of a delay card is carried out measuring the distance be-
tween reels in a speaker system. Keeping the way that is more advanced in the sound plane
of the speaker system as reference, will measure the distance of their reel with the other
ones. The delay that should insert in the other ways is gave by the next formula:
Db (mm)
Tr = (ms).
Vs (m/ s)
Where Db is the distance between the reels in millimeters, Vs is the sound speed in
meters per second (340 m/ s) and Tr is the delay time, in milliseconds.
For example, if you have a two ways speaker system cabinet, with the reel advanced 3
cm with regard to the low reel, you would obtain the next result:
30 (mm)
Tr = = 0.088 ms = 88 µs.
340 (m/ s)
Therefore, in order to align this system, you will introduce a delay of 88 µs in the high
way. As seen the theoretical calculus it is not complicated and allows us to adjust the delays
between the different ways obtaining a good addition among them.
When the real measure of the distance between sound planes is complicated or inex-
act as it is the case of folded horn bass bin, you will be appealed to the experimental mea-
sure with gauge instruments. To make this, you will excite both speakers simultaneously with
a pulse generator and you will visualize the waveform in a oscilloscope with the help of a
microphone and a console. As pulse generator could be used a portable one of the employ-
ees in order to measure the phase between speakers. The scheme of the procedure of
measuring could be observed in the next picture:
PLACING A DELAY CARD:
Before placing the delay card you should adjust it, for this it is recommended that reads
the previous sections carefully, if you haven't done yet.
In order to place a delay card in the main board, follow the next steps: