Perfect Parts

[leonski]

In times past I watched and even participated in debates about 'parts'.
2 schools, starting with 'Parts Is Parts' and migrating to 'Different can be Better'.

I'll just cover speaker wire for now.

Sure, people with high power amps and low sensitivity speakers tend to Prefer low resistance wire.     I use Belden 10ga from Blue Jeans......in VERY short lenghts since the amp is 2' from the speaker.

But resistivity is just part of the measurables involved with speaker wire.    Many recommendations out there, but I 'tend' to like 14ga in lengths up to 25 feet per........For Very high applications which are 
 used in that fashion?   Might consider 12ga.      But that verges on overkill.   Starting over?   I would NOT buy the 10ga Belden again.    

You can have Capacitance.   In extreme cases this acts as a crossover filter and can change the perception when this wire is used VS some 'other' wire with much less capacitance.
 ANY 2 conductor pair will exhibit this phenom.
You can have Inductance.   Acts as a 'coil of wire'.      And also effects what you perceive......As a filter AND effects phase response.   

Every other part used in the construction of your gear also has 'other' characteristics'.
Inductors?    Have measureable capacitance and resistance
Capacitors?   Resistance and inductance
Power Resistors? Can be 'wirewound' which is an inductor....

www.passlabs.com/technical_article/speaker-cables-science-or-snake-oil/

 Nelson Passs may be able to help straighten some of this out.....



No such thing as a 'pure' component.....

[405x5]

Mar 19, 2024 23:22:57 GMT -5 leonski said:

“I'll just cover speaker wire for now.”

Thank you Leonski !
(High time somebody Addressed this)

[leonski]

I'd like to make a few remarks about inductors.....

There are 2 major types....
1. Aircore
2. Ironcore

A few advantages and DISadvantages of either type. Aircore has vastly higher power handling while iron may be more compact....

All inductors have a measure called DCR.....DC Resistance. In my panels? The Ironcore inductor is of 16ga wire and is 0.40 ohms.......
Given the rest of the panel, this MAY limit maximum power. Which is really a red-herring concern
Many of the 'modders' in years past went with the nearest aircore value, usually a 'dewind' of a stock part. They would be either insulated (varnish / synthetic / plastic or a flat ribbon.
ALL had anything from lower to a LOT lower DCR which effects the 'balance' of the FR of the panel. But not a lot, maybe 1db or so higher LF output with the lesser DCR inductor.

There is no such thing as a 'perfect' inductor. But there is an 'IDEAL' inductor. A fine point maybe, but it matters.
An IDEAL inductor will have the same number of layers of wire as turns per layer. This ends up being a square cross section. And concentrates the field most closely TO the part.
Many dewinds and just 'regular' parts ignore this and have random seeming shapes. This is sub-optimum.

When I did design work for a new inductor for my panels? I had several design goals. 1. DCR within 5% of stock 2. 14ga or 13ga wire. 3. 'IDEAL' shape 4. Use stock PVC sizes for winding bobbin.....

Using an online inductor calculator I did accomplish all goals. I went thru multiple itterations and converged on the right values. Its been a while, but IIRC? 100+feet of 13 or 14 on a 2" PVC fitting (larger than pipe size)
with the same number of rows as layers.......DCR was 0.38ohms, which is nearly unmeasureable against stock.....

One LAST point. in Multiple Inductor crossovers? ALL should be at right angles to one another. standing them all up in a row? BAD Or all 'flat' to the board? Also BAD. Interactions are less than 100% predictable
and you may create unintended effects....Usually not to the good.

[leonski]

Resistors are NO BETTER.
the Ideal (perfect) resistor is JUST resistance.

In point of fact? there is some Series inductance and Parallel capacitance.
This means some response effects at high frequencies. I'd guess Well Beyond 'audio'......
Certainly RF is on the plate. (no pun intended)/

For a bit of history? the Carbon resistor worked for generations. But they are NOISY while the newer types are much quieter and longer lasting.
I don't know that you can get better than a 5% tolerance.....or how badly they 'age' against original value.

The rest of 'em? Various 'films' and such, sometimes deposited (sputter, maybe?) on a ceramic base. In this category are 1% tolerance and Better! The very quietest materials
and in 1/4 watt size are PERFECT for Stepper Type level controls......Some use Surface Mount and are beyond me to hand assemble......