2. amps-preamps
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Measurements - Clearly Explained

Hi Everyone,

I found a page which explain amplifier measurements which I think many would find useful on the SoundStage web site:

http://www.soundstage.com/measurements/test_amplifiers.htm

They seem to be suffering from bad links. If you get directed to "SoundstageMagazine.com" just remove the "Magazine" part.

One thing a lot of people have questions about are the impedance of "real-world" loudspeakers. This I found at the Stereophile site, here:

http://www.stereophile.com/reference/60/index.html

Of course, this is 1 specific speaker load, but it does represent the challenges posed by many 2-way, dynamic loudspeakers.

Best,

E
erik_squires

Showing 5 responses by erik_squires

erik_squires OP
16,678 posts
 
Here is a paper I just discovered an excellent paper on Damping Factor from Wikipedia:

https://en.wikipedia.org/wiki/Damping_factor#cite_note-3

which also references a paper from Nelson Pass discussing how matching the amplifiers to specific speakers (lots of full-range and high efficiency drivers could be useful):

http://www.firstwatt.com/pdf/art_cs_amps.pdf

While the paper focuses on HE speakers and using current source amplifiers (i.e. very high impedance output)  I think it's a great way to dive in deep into speaker / amplifier interrelationships.

I'm not sure if I can create a current source amp in Xsim, but it is a fun challenge. :)


Best,


E
erik_squires OP
16,678 posts
 
@wolf_garcia

Nothing wrong with that at all in my mind. :)

I just don't like influence/idea peddlers promoting ideas about power and impedance not supported by facts.

Buy and listen to what you like!! :)

Best,

Erik
erik_squires OP
16,678 posts
 
Hi Wolf!

Those are always great finds.

But as an engineer, anything that sounds good, I'd like to know why so I could replicate it, whether or not it goes with established dogma.

Like, maybe it adds plenty of 2nd order distortion, or has noise in the treble which enhances digital recordings.

Best,

E
erik_squires OP
16,678 posts
 
Hi Ahendler,

I'm not sure how much voicing you think happens without tools, but yes, the point to the links and simulations is to help the layperson see exactly what the amplifier/speaker interaction is like in terms of impedance and output.

Best,

E
erik_squires OP
16,678 posts
 
Hi Everyone,

I put together simulation files. If you have a PC or at least a Windows VM you should be able to grab the XSim crossover software (free!) and these files and play around yourself.

http://www.diyaudio.com/forums/multi-way/307912-simulated-speakers-amp-z.html#post5081657

The simulation file I put together uses the Steroephile simulated 2-way load, and it is especially useful in examining how an amplifier’s output impedance affects the speaker frequency response.

Of course, buy what you like to listen to! The docs I present here are merely to enhance our technical understanding and to accelerate the sharing of knowledge.

If you want to play around with simulations, please join me over at the DIY site where we can attach images and files.

Best,


E
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