[Regnad]

Well, almost.

With all the talk of the effect that the speaker wire would probably have on the NC400, given the low output impedance, I tried something new (to me) ...

The NC400s are right behind the speakers with about 8 inches of 12 AWG wire connecting them to the speaker terminals.  I have not gone back and forth but, to my ears, there is a very noticable improvment in bass control, space and sonic "weight".   I am looking at my pretty Acoustic Zen speaker cables and I may not need them.

I intend to build a chassis that will house either the SMPS600/NC400 or the SMPS700/NC1200 setups and place the AC and XLR connectors on one end and straight wires to the speakers at the other end.

Anyone else placed the amp right at the speaker?   I will refrain from opening up the MBLs to further shorten the cables. 

[cab]

The ncore 1200 is only available to OEMs....

[Regnad]

Nothing stopping me from removing them from the "OEM" one's I will have very soon!   Bwa-ha-ha!

Now, that's an expensive way to go DIY, you'd probably think.

[cab]

Well, there is that option I guess! Let us know how it works out...

[mkcarnut]

I was originally going to mount my nCores directly behind the speakers (so, this would have ended up with <1' of speaker wire) with the nCores on pedestals.  But, I went with a wall-mounted design, so I will end up with ~3-4' of wire from wall to speaker (and XLR cables from pre-amp to wall-mounted amps).  Had I not wall-mounted, I would have needed 6-7' of speaker cable.

As I dug into the whole topic of speaker wire lengths and gauge, I confess I don't really "get" the need for really low resistance wires.  From the calculators provided - even my current wires were far lower resistance than my speakers and would result in almost no dB drop.  Cutting the speaker wire length to as short as I can get it (~3.5') and running the thickest cables I can cram into typical connectors (dual 10 gauge per connection) does indeed drop dB loss but in an inaudible way and the resultant impact on current vs. voltage is not meaningful either.  And, if ultimately the speaker resistance is dramatically higher than that of the cable...it's hard to see what's to be gained my a very, very slight reduction in speaker wire resistance.

So, I don't really see what the potential gain would be...other than "cool factor" of having the amps directly behind the speakers (which is a key reason I did wall-mounted...the "cool factor").

If I am missing something, I would certainly appreciate being educated...

Mark

[Julf]

As I dug into the whole topic of speaker wire lengths and gauge, I confess I don't really "get" the need for really low resistance wires.

I guess it depends on if you buy into the theory behind "damping factor". A big issue has been made of the very low output impedance of the nCore design, and using thin, higher-resistance wire negates the potential benefits of the low output impedance.

[mkcarnut]

I get the theory of damping factor, but what I don't get is that the amp can only "see/feel" the cumulative resistance it is pumping into.  So, the amp does not know if there are (to make up a ridiculous scenario) 14 different connections, each of some defined resistance after the amp, with the first 13 being in the range of 0.001 to 0.1 ohms each (per typical wires) and the 14th being the speaker at 2-8 ohms (frequency-dependent, of course)...or if there is a single load equal to the cumulative resistance of the 14 connections.  All the amp "knows" is that it is facing a load at its outputs.  Further, if the speaker dominates the overall resistance post-amp (which, from all practical applications I have seen is the case), then the wire is "rounding error".  Right?  Or am I missing something?

Note that I say this but I have paired 10 gauge wires from my nCores to my Maggies...1 pair per terminal...so four 10 gauge per speaker.  This is as big as I can possibly fit into my terminals on my amp and speakers.  So, my wire resistance is about as low as I can get, in practical terms.

Bottom line, I am just seeking to learn about why people really think the wire resistance actually matters when it looks to me that the speaker dominates.  Any thoughts on that point would really help educate me on this topic.

Mark

[Julf]

Bottom line, I am just seeking to learn about why people really think the wire resistance actually matters when it looks to me that the speaker dominates.  Any thoughts on that point would really help educate me on this topic.

You are right - the speaker voice coil resistance definitely dominates. That's why it is usually considered that a damping factor of 50 is "enough" and higher damping factors don't give any further benefit, but a long, thin wire can definitely push the damping factor below 50.

Wikipedia has a pretty good table of maximum wire lengths as a function of wire gauge and speaker impedance.

[mkcarnut]

Thanks for confirming what I thought.  Someone posted a really nice calculator here over the last month for wire size (gauge/length) vs. resistance and various other things.  I played with it a bit and it was quite fun.  But, basically, I already had sufficiently low resistance cables.  At the time, it was dual 12 gauge per terminal that were ~6' long...the dual 10 gauge I have now were to avoid the need to cut those to shorten them to account for my new wall-mounted nCores.  This change, per the calculator, dropped resistance significantly but would not be projected to have any sonic impact.

Mark

[Julf]

This change, per the calculator, dropped resistance significantly but would not be projected to have any sonic impact.

As long as that 6' isn't running next to the antenna mast cable of a powerful radio transmitter

[Guy 13]

Hi all Audio Circle members.

This is the criteria I would use to test/show the sonic differences between different types of speaker wires.

All wires must be the same length.

All wires must be the same gauge (Caliber)

All wires should be terminated with the same type and/make of connectors.
I would prefer to see bare wires.

Quality switch boxes at both ends
and as close as possible to the amplifier/speakers.

The wires would not be visible to the listeners.
(Just seeing the different gauges, colors, insulation type might influence their evaluation.)

To me, (But not to everyone),
the switching between the two different types of wires
should be done by altering between the two wires every 10 to 30 seconds. 

The questionnaire should include the following choices,
Between the two wires tested.
Better, worst and no difference.
or
Good, bad and same, etc…

Any one agrees or disagrees on my testing protocol?

Guy 13

 

[Julf]

All wires must be the same gauge (Caliber)

That might be hard to accomplish in practice.

Any one agrees or disagrees on my testing protocol?

Agree - as long as you do enough listeners (or randomized sessions, if only one or a few listeners) to make the results statistically valid.

[Guy 13]

That might be hard to accomplish in practice.

Agree - as long as you do enough listeners (or randomized sessions, if only one or a few listeners) to make the results statistically valid.

Hi Julf and all Audio Circle members.

I had in mind a minimum of eight listeners.

Some musicians,
 
some audiophiles,

some one that knows nothing or not much about music or equipment
and (Why not) some woman.

Of course at least five (05) sessions.

Guy 13
 

[Julf]

I had in mind a minimum of eight listeners.

Of course at least five (05) sessions.

Sounds good!

[Regnad]

DBT with speaker cables, good luck...   

I am no tweaker but, after modifying the amp cases to have AC/XLR on one side and straight wires from the NC400 screw posts right to the speaker connectors on the other, the sound is much better.  I have no idea why but when I look at it, it just "seems" intuitively right that this should be a better method.   Again, it's the sound that is the clincher.

IMO, it makes much more "sense" than footers, IEC metals, rigid cases,  etc.   I (probably for the best) can't hear some things that people seem to readily distinguish.   Imagine me and a Shakti Holograph sales person who would lift up and lay down those wooden assemblies and say "Wow, do you believe how much better that sounds?"  This was in my living room and I honestly could not tell the difference.

I look at it like this:   The amp is not driving a 4 ohm resistor but, as we know, resistance, capacitance and inductance.  The closest (electrically) that you could put an amps low output impedance to that network seems a good idea. 

[dan92075]

Lets consider a mechanical analogy:
Imagine you were not driving your speaker with an amp,  but instead you had a long rod to the speaker element,  which you yourself would have to shake back and forth to generate sound.

You would want an absolutely stiff rod, especially the longer the rod was.

What you would not want is a rod that had a springiness to it.   As you went longer with your control rod, that springiness would make it very hard to control the speaker element the way you want.

The capacitance/inductance in a speaker cable is exactly that - it creates a type of springiness, so what you are controlling on your side is not exactly what is occurring on the speaker side.

Add to this,   when a speaker element is in an extended position it wants to spring back to its nominal position and you have a back EMF for example,  which is why speakers have reactive components as well.

So it makes sense you want to be close to the speaker terminals, and not 25ft away for example.

For example,  I used to have a Spectron amp with remote sense that effectively made the speaker wire disappear.
The difference with 25ft of speaker wire (I purchased my house that way) with remote sense on an off is pretty impressive.
It was a very quick way to show that speaker wire was affecting performance.
Since I am going with Ncore now I will be moving my amps directly behind the speakers (since ncore is so small I have enough room),  and then using 25ft of balanced interconnect instead.

The only downside of amp being too close to speaker  is the vibration of the speakers can get transferred to the amp.
This I have not experienced myself yet,  but that could be mitigated from what I understand by using cable connections on the amp that have damping as well as footers with proper damping.

[Speedskater]

Dan, that doesn't make any sense.
The capacitance/inductance in a speaker cable is exactly that - it creates a type of springiness, so what you are controlling on your side is not exactly what is occurring on the speaker side.

The typical passive crossover has orders of magnitude more capacitance/inductance than any reasonable speaker cable.

[dan92075]

The inductance of 25ft of typical speaker cable results in ~.6ohms of reactance at 20kHz.
If one has 3ohm speakers one can see why there would be an effect.

I would be careful about comparing to the inductors/capacitors values in passive crossovers.
Yes they are large - but they are huge to either block the signal or pass the signal - i.e. you do not measure huge values of reactance when you measure across your speaker terminals.

[srb]

The inductance of 25ft of typical speaker cable results in ~.6ohms of reactance at 20kHz.
If one has 3ohm speakers one can see why there would be an effect.

I would venture that the majority of systems use 6 to 8 feet of speaker cable, so for those people your reactance estimate would more likely be reduced to somewhere between 1/4 to 1/3 of that value.
 
Steve

[Julf]

The inductance of 25ft of typical speaker cable results in ~.6ohms of reactance at 20kHz.

But a thicker cable has less inductance. And for the purposes of damping factor, you are more interested in resistance rather than reactance.

I agree that remote sense is a good idea for eliminating the effects of the speaker cable - but it makes the system much more sensitive to induced noise.