audioholic cable buying guide

[Guest]

<font color='#000000'>I was wondering if you could tell me what might be better for Interconnects. Would this be a twisted pair configuration or a co-ax type cable? Also, in the article on your site, it states that you can have as much as a few hundred pF of capacitance in a cable and still get a 3db point well above 100khz. What do you consider a few hundred pF?  Are you refering to 300, 400 or 500 picofarads? Also is this the total capacitance for the entire cable length? What do you mean by a 3db point? Does this mean 3 decibels of attenuation or a 3db level of sound at 100khz, which is out beyond the hearing range anyway.</font>

 

[gene]

<font color='#000000'>Joe;

Good questions.

Both Coax and Shielded Twisted pair cables are good choices for audio. &nbsp;Coax is preferred for video because of better frequency response and impedance matching. &nbsp;It is also usually preferable to twisted pair designs for long cable runs since these designs generally have lower capacitance. &nbsp;I think a safe recommendation for capacitance for audio interconnects to avoid audio losses and minimize risk of amplifier instabilities is around 300-400pF total. &nbsp;Some of the better audio IC's on the market typically have 20-30pf/ft so this should not be an issue.

3dB point stands for the the &quot;half power frequency&quot;. &nbsp;For an RC network 0 &lt;/= w &lt;/= 1/R*C where w =2*pi*f

It is a good idea to have a 3dB point on interconnects or speaker cables for high performance playback at least a decade past the audible range (40KHz) to avoid audible group delay and frequency response losses.</font>

 

[Guest]

<font color='#000000'>Thanks for your responce. I've noticed that with twisted pair cables there are two numbers for capacitance. One number is the level of capacitance between conductors and the other is the capacitance between conductors and sheild. When looking at the level of capacitance in a twisted pair type interconnect what number do you look at? Do you use the sum of the two numbers in order to get the total capacitance per foot? I've also noticed that video  coaxial cable has the lowest capacitance numbers. Would a video cable with a multistranded copper center conductor be the best choice for low capacitance Interconnects? Some say that low capacitance doesn't really matter with typical interconnect lenghts of 1-2 meters. Their reason is that at these lenghts, most good cable will have low enough capacitance not to cause problems.</font>

 

[Guest]

<font color='#000000'>Where did you go Gene? You haven't replied to my post.</font>

 

[gene]

<font color='#000000'>Joe;

I need to see an example to know exactly how the cable is configured. &nbsp;If the vendor lists the pair to pair capacitance of the twisted pair separately from the capacitance of the shield to return conductor, I would probably add the two since they would effectively be in parallel. &nbsp;Send me a link or site a specific example and I will look into it.</font>

 

[Guest]

<font color='#000000'>Gene, go to www.canare.com look at the specs for the starquad and the L2t2s cables. They will be listed in the online catalog &nbsp;(catalog number 11.) Thanks</font>

 

[Mark7]

<font color='#000000'>Gene how come you haven't answerd my post. btw this is joe. I had trouble logging on. I don't know what happened? I'm now registired as mark7</font>

 

[gene]

<font color='#000000'>Joe;

I appreciate your enthusiasm on this subject and your numerous follow up emails. &nbsp;However, I have many things on my plate right now (especially preparing for CES), so it may take some time for me to get back to you. &nbsp;Just a quick comment, remember the following relationship for capacitance:

Series Capacitance: Cs = (C1*C2)/(C1+C2)

Parallel Capacitance: Cp = C1 + C2

Hope this helps.</font>

 

[Mark7]

<font color='#000000'>Thanks for you responce Gene. Maybe when you find the time you can explain the subject of capacitance and how it applies to audio cables a bit more. I had no idea you had so many things going on all at once. Sorry if I was being a nuisance.</font>

 

[Guest]

<font color='#000000'>Hey, this is a good web site.

I am not an audio guru atleast in the sense of hi-fi equipment. &nbsp;However I am a musician and produce sound gigs weekly for small gatherings in a church youth program with live music. &nbsp;I also posses a good understanding of physics and electronics but again I am no guru.

Recently i bought a home entertainment system and the sales person talked me into buying &quot;superior&quot; cables and convinced me that the supplied cables &quot;would not Cut it&quot;. &nbsp;So I did. &nbsp;

I also forgot . . &nbsp;. I am a sceptical person and usually need good technical &quot;backup&quot; for claims of superiority of one system (or idea) over another. &nbsp;So researched the electro-physical properties of cables (not just for audio), on many, many websites and read numerous tech articles. &nbsp;Some of which have nothing to do with this debate. &nbsp;To my (not-so-much) surprise, the overwhelming majority of technical (and I really mean technical!) authorities using scientific tests and double blind un-biased tests C O N C L U D E &gt;&gt;&gt;&gt;&gt;&gt; there is no scientific proof neither audiably nor physically that cables produce such a drastic difference in sound or video quality. (within reasonable quality cable)

maybe some one can answer this for me. . . .

In music we use balanced cables from our instruments to the mixer or preamp inputs because of the long runs these cables sometimes have to make. &nbsp;The way they work - or atleast I understand- is that the mono signal is split into two parts ran in &nbsp;isolated wire. &nbsp;One of those signals is 180 degrees out of phase and polarly inverted, thus any interference incurred through the long run will spike each cable identically (positive or negative in each. &nbsp;On the other end of the run the signals are processed and one signal is polarized to match the wave pattern of the other original signal. &nbsp;This causes the interference spikes on the overlayed wave forms to cancell each other out, eliminating extraneous noise. &nbsp;this is how &quot;balanced&quot; cables work. . .So I understand.

The big question is ----How does Monster Cables' claim that their cables are balanced. &nbsp;There is only a center conductor and a ground. &nbsp;Any balanced cable I've seen is three wires. Two signal carrying and a ground. &nbsp;Please explain !!

Thanks!

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