Mr. foxen wrote:
My mate is studying this course. he sent me the lecture powerpoint slides, since I have an interest in such things. Includes this:
Danger Low Power
If an amplifier is over driven:
harmonic distortion increases
more high frequency energy than usual
tweeters may be underrated
DC signal generated
inductive reactance plummets
high currents destroy voice coils
Section on speakers:
A loudspeaker enclosure will:
Add panel resonances
Produce standing waves
Inflict it’s own frequency response
To reduce this, the construction must be:
Under bass reflex enclosures:
Tends to “hoot” and “chuff”
This is like, all the classic wrong info found on DIY forums, but its part of a degree and I assume the exams match up.
In some instances: an example of myth being perpetuated in a formal setting leading to a qualification.
I wonder if a pre requisite to the course was a hearing test?
I'm just dabbling in doing my first amp repair and there is DC generated in amps.
Step one after making sure no smoke gets out is to measure DC at the output and then correct DC offset (from my amp service manual)
Also, in the same manual, it says when adjusting Short circuit detector:
The desired AC voltage is superimposed on a DC voltage of 9V, so the CRO or millvoltmeter will need to be AC coupled.
I guess the argument from Bill would be that bracing ensures rigidity...
DR 250: x 2 (melded array) with March 2012 plans. 2 more under way with CD horn
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting
"like"s would be most appreciated...