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
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
I would like to add that measurements and amplifier measurement tools are needed to design amplifiers. They are not needed for buying amplifiers, since they tell you nothing how an amp will sound. Remember, most amplifier designers do the final voicing of there amps by ear, not measurements
Alan
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
The Dennis Had "Inspire Fire Bottle" amp I bought recently has NO specs anywhere I can find, except descriptions in his Ebay comments regarding things like output from various tubes and power supply design…I bought it because it’s cute (the first consideration by any true audiophile), and after reading 10,000 pages of comments here and there. Had says things like "You’ll be listening to your record/music collection as if you were hearing the performers for the first time. This jewell delivers the emotion of the music ... big time. The amp plays like a 50 watter with amazing control and slam." As far as my experience with it goes, he’s utterly correct. It works well with what I already have (preamp, DAC, cables, efficient speakers, etc.) so maybe I’m just lucky.
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