Pro Gear vs Audiophile Gear

[DonH50]

Nope, "The Smokester" ain't blowing smoke this time; he got it right.

Ohm's Law: I = V / R == current (Amperes) = voltage (Volts) divided by resistance (Ohms)

Lower resistance means more amps are needed for the same voltage, and most of our sources and loads are more voltage'ish than current'ish.

Pro audio systems typically work with 600 ohm impedances in a balanced configuration. While the mixer/preamp output is often low-impedance (1 - 10 ohms), the load is only 600 ohms (effective). A consumer audio component typically has input (load) impedance >10k ohms, often approaching 100k ohms. Lower impedance improves bandwidth and reduces noise sensitivity in the long runs often found in pro installations/stage setups, and of course live sound guys (like I used to be) rarely get to run the cables where they would sound best so a lot of times alongside the power cords they go... Yuch!

HTH - Don

p.s. Thanks for the kudos, y'all! Every now and then the thread turns to something I actually know a smidgen about...

 

[The Smokester]

Just to add: The term "impedance" includes the concept of resistance but is really broader. Impedance takes into account the ability of some elements in a speaker load to change the phase of a time-varying signal. Usually impedance varies with frequency.

Sometimes speakers come with specifications that show both the magnitude of the impedance (usually mislabelled as a resistance for simplicity) and phase as a function of frequency. It is impedance which is the more fundamental engineering parameter that describes this behavior and its origins. A "resistive load" is a load that does not change phase and for that case the impedance would be the same as the resistance. Speakers are seldom a purely resistive load.

Impedance can be represented abstractly (mathematically) as a 2-dimensional vector with a length and a direction, or as a complex number r + j x. j is used in science and engineering to represent the Sqrt(-1) since i, the usual standin in mathematics, was already taken to represent instantaeous electrical current.

 

[Gregadd]

Speakers are seldom a purely resistive load.

Magnepans are. IMO that is why they have met with such wide spread success. They are popular with all the amps. Well not all.

 

[Ethan Winer]

A good example is a certain low-noise opamp that was very popular some years back. In a voltage circuit, it was fantastic, so of course manufacturers snapped it up and used it everywhere since stocking one opamp is cheaper than two and it was all the rage in the press.

Are you talking about the NE5534? I'm sure it's okay to name names here.

--Ethan

 

[DonH50]

Impedance is also defined in the "Units" thread in the Technical Forum here: http://www.whatsbestforum.com/showthread.php?990-Units-Symbols-and-Terms-Oh-My!

Ethan, that is a good guess and in fact I should look that one up, but I had the OP-27/37 in mind... Great little op-amps, but not great as phono amps. I had some friends who worked on them and were a bit annoyed at their mis-use.

IMO! - Don

 

[FrantzM]

Speakers are seldom a purely resistive load.

Magnepans are. IMO that is why they have met with such wide spread success. They are popular with all the amps. Well not all.

I am a Magnepan fan, own several speakers in their lineup including the TYmpany, the SMG and the top of the Line and still love them. They usually have very well behaved impedance but is not truly resistive... The modulus and the phase of the impedance varies quite a bit , not as wildly as other speakers but they vary with frequency.
THis for the MG 1.6 .. Smooth and nice but not resistive.

THe MG 3.6 vary even more with a peak f close 14 ohm at 600 Hz but overall is mostly around 4~5 ohms.

All n' all very easy load for any decent amplifier.. Let's say quasi-resistive

 

[RUR]

Could be a whole lot worse, Frantz.....

http://www.stereophile.com/floorloudspeakers/145/index10.html

 

[FrantzM]

Could be a whole lot worse, Frantz.....

http://www.stereophile.com/floorloudspeakers/145/index10.html

I know !!!!

for all practical purpose Gregadd is right: Magnepan are the closest thing to a resitive load ...

 

[Gregadd]

I am a Magnepan fan, own several speakers in their lineup including the TYmpany, the SMG and the top of the Line and still love them. They usually have very well behaved impedance but is not truly resistive... The modulus and the phase of the impedance varies quite a bit , not as wildly as other speakers but they vary with frequency.
THis for the MG 1.6 .. Smooth and nice but not resistive.

THe MG 3.6 vary even more with a peak f close 14 ohm at 600 Hz but overall is mostly around 4~5 ohms.

All n' all very easy load for any decent amplifier.. Let's say quasi-resistive

Could it be the addition of the ribbon tweeter, er, quasi- ribbon tweeter that caused them to be, er, quasi-resistive?

 

[c1ferrari]

Just came across this thread...

I have Beveridge Model II (restoration project), Beveridge Model III, and Dali MegaLine III loudspeakers (currently, primary speaker). The electronics are balanced and valve.

I just listended to ATC SCM150 ASL Pro loudspeakers, using analog reels as source material. These may very well be my next speaker

 

[egidius]

a "friendly" studio has got Geithains, amazing, but since I go to work there from time to time, I refrain somehow to ask to much, must do so next time! egidius

PS the sound is amazing, but so is an atc-studio near me here.

 

[Lee]

I am a Magnepan fan, own several speakers in their lineup including the TYmpany, the SMG and the top of the Line and still love them. They usually have very well behaved impedance but is not truly resistive... The modulus and the phase of the impedance varies quite a bit , not as wildly as other speakers but they vary with frequency.
THis for the MG 1.6 .. Smooth and nice but not resistive.

THe MG 3.6 vary even more with a peak f close 14 ohm at 600 Hz but overall is mostly around 4~5 ohms.

All n' all very easy load for any decent amplifier.. Let's say quasi-resistive

I sure love my 1.6s.