Verticle TV & Music

HIGH PERFORMANCE MICROPHONE CABLE

In the previous column, we talked about the three factors to choose in analog microphone cable: ruggedness, low noise, and performance.  We had enough space to knock of the first two, and that leaves performance.

What is "high performance" in a microphone cable?  This simple question is clouded by a lot of pseudo-science and mis-information.  Exotic materials, tightly twisted pairs, silver conductors are sometimes mentioned. And many parameters are cited as "important". But the actual list of "important measurements" is really quite short. Table 1 shows a list of measurements and parameters of cable that are often cited as "important" with a note of how important each one actually is.

PARAMETER

MEASURED IN

EFFECT ON SIGNAL

Resistance

Ohms (Ω)

This concerns the size of the wire and the material it is made of. While resistance can affect distance, based on IR loss, it affects all frequencies equally so does not alter the signal. The effective signal distance is much more related to following parameters. Larger gage (AWG) wires might be chosen to increase the pull strength or ruggedness of a cable.

Capacitance

Picofarads (pF)

Stores energy between the two conductors in any cable.  Since it affects high frequencies more than low, the effect is not linear, not the same at all frequencies.  This gives cable the ‘slope' or ‘attenuation' that increases with high frequencies.  A key parameter.

Inductance

Microhenries (μH)

Stores energy between the two conductors in any cable.  However, the effect is opposite to capacitance and the two effects (called "capacitive reactance" and "inductive reactance") cancel each other out.  Since the inductive reactance in a cable is much smaller than the capacitive reactance, capacitance always win.  For that reason capacitance is listed in a catalog or data sheet, where inductance is not even mentioned.

Impedance

Ohms (Ω)

Impedance is the total effect of resistance, capacitance and inductance on a cable. However, it is only important when the length of the cable approached a quarter of a wavelength at the frequency being carried.  For analog audios highest frequency, 20,000 Hz (20 kHz), the wavelength is over 9 miles, and the quarter-wavelength over 2 miles.  Since we never run cables that far, the impedance of the cable is not even considered, and usually not listed in a catalog or data sheet.

Skin Effect

Sometimes mentioned in audio, this effect moves the signal from traveling down the whole conductor to the outside of the conductor at high frequencies.  While measurable at audio frequencies, it is insignificant until the signal is 100 kHz or more, and generally not considered until 1 MHz or more, way beyond analog audio.

Table 1

So, you will note that there is really only one parameter to consider, and that is capacitance. And the lower the capacitance, the better the performance of the cable. This can also be shown in a different way.

In Table 1 it says that you can't go far enough to make the impedance of the cable important.  However, this is not true of the impedance of the equipment sending and receiving the signal.  In fact, you can calculate how far you can go on a cable by knowing the capacitance of the cable (in picofarads-per-meter, pF/m.) and the source impedance of the sending device. (If this is a microphone cable, then you want to know the source impedance of the microphone.)

Table 2 below shows the results of these calculations for various source impedances and cable capacitances. The distances shown are where a signal of 20 kHz would be attenuated by 1 dB, a very slight amount.

Source impedance

49 pF/m

66 pF/m

98 pF/m

164 pF/m

50 Ω

1648m

1236m

824m

495m

150 Ω

571m

412m

275m

165m

600 Ω

138m

103m

69m

41m

1000 Ω

83m

62m

41m

25m

10 k Ω

8m

6m

4m

2m

Table 2

Table 2 explains why high impedance microphones (10kΩ), sometimes used with consumer equipment, only come with short cables.  Even the lowest capacitance is effective to around 8 metres until the signal is affected.

You will also note that professional microphones, typically around 150 Ω impedance, can go hundreds of meters, even with cheap cable. And with good cable, with low capacitance, over half a kilometer.  This is also why some of those super-expensive microphones have very low output impedance, such as 50 Ω. (And some of those ancient condenser microphones allowed you to change their output impedance.) Look at the distance those signals can go.  With a really low source impedance, the cable, in effect, disappears and has no effect on the signal. That first column applies to Category 5e, 6 and other computer data cables, such as the single pair Category 5e (Belden 1353A) mentioned in the previous issue.

And there are cables even lower capacitance than that, such as Belden 1800F, with a capacitance of 43 pF/m.  This was intended to be digital audio patch cable.  As such, it must have very low capacitance for those digital signals.  But that means you can take advantage of that requirement for digital (low capacitance) and use it for analog audio.

This also means that all those single pair and multipair digital Audio Cables, make fabulous analog audio cables, because of their low capacitance. And that also means that, if you even move from analog to digital in the future, you won't have to pull those cables and re-wire that installation.  It's already wired for digital !  You're "future-proofed" !

And if your customer balks at using a cable clearly marked ‘digital' for an analog application, just use some rubbing alcohol and rub off the word "digital".  After that, the cable will work perfectly for analog.  In fact, it will give you the best analog performance you have ever heard!

About the Author

Steve Lampen has been with Belden for 19 years and currently is Multimedia Technology Manager and Product Line Manager for Entertainment Products.  He has an FCC Lifetime General License (formerly an FCC First Phone License) and is a BICSI Registered Communications Distribution Designer. His latest book "The Audio-Video Cable Installer's Pocket Guide" is published by McGraw-Hill.

Visit our web site www.beldenapac.com or email us info@beldenapac.com

GN604S-125 $102.95 125 ft. Spool of 4 Gauge AWG Tsunami Silver Power / Ground Cable Wire

US Auctions Australian Auctions Austrian Auctions Belgian Auctions Canadian Auctions French Auctions German Auctions Irish Auctions Italian Auctions Dutch Auctions Spanish Auctions Swiss Auctions GB Auctions

Best Match Items Ending First Newly-Listed Items First Price + Shipping: Lowest First Price + Shipping: Highest First

25 feet 22 AWG Silver Teflon Wire Red 19 Strands $5.35 Time Remaining: 13d 18h 44m Buy It Now for only: $5.35 Buy It Now

AWG28 03MM Solid Core UPOCC SILVER Audio BARE WIRE 30M $29.99 Time Remaining: 1h 48m

22 AWG Silver Teflon Wire Assortment 50 feet 19 strand $12.45 Time Remaining: 13d 18h 46m Buy It Now for only: $12.45 Buy It Now

AWG28 03MM Solid Core UPOCC SILVER Audio BARE WIRE 90M $89.99 Time Remaining: 1d 16h 57m

25 feet stranded 28 AWG Silver Teflon Wire Red $4.75 Time Remaining: 12h 14m Buy It Now for only: $4.75 Buy It Now

New 24 AWG 19 36 MilSpec Tefzel ETFE Silver Copper Wire White 2400 $34.99 Time Remaining: 1d 9h 1m Buy It Now for only: $74.95 Buy It Now

TURNTABLE TONE ARM HARNESS 32AWG SILVER WIRE WITH GROUND LEAD $24.99 Time Remaining: 11d 15h 24m Buy It Now for only: $24.99 Buy It Now

AWG18 10MM Solid Core UPOCC SILVER Audio BARE WIRE 6M $69.99 Time Remaining: 1d 17h 33m

TURNTABLE TONE ARM HARNESS 32AWG SILVER WIRE G P CLIPS $19.99 Time Remaining: 11d 15h 24m Buy It Now for only: $19.99 Buy It Now

AWG28 03MM Solid Core UPOCC SILVER Audio BARE WIRE 50M $49.99 Time Remaining: 2d 5h 15m

50 ft Strand Red Teflon wire 30 awg Silver Plated $8.90 Time Remaining: 29d 4h 5m Buy It Now for only: $8.90 Buy It Now

25 feet 16 AWG Silver Teflon Wire White 19 strand $11.30 Time Remaining: 14h 18m Buy It Now for only: $11.30 Buy It Now

AWG24 05MM Solid Core UPOCC SILVER Audio BARE WIRE 30M $89.99 Time Remaining: 2d 1h 38m

25 feet 20 AWG Silver Teflon Wire White 19 strands $6.45 Time Remaining: 18d 5h 26m Buy It Now for only: $6.45 Buy It Now

AWG28 03MM Solid Core UPOCC SILVER Audio BARE WIRE 20M $19.99 Time Remaining: 2d 8h 47m

25 feet 22 AWG Silver plated OF Copper Wire White Solid 1 Strand Kynar $6.25 Time Remaining: 22d 15h 24m Buy It Now for only: $6.25 Buy It Now

AWG24 05MM Solid Core UPOCC SILVER Audio BARE WIRE 10M $39.99 Time Remaining: 1d 18h 40m

125 2 Conductor 24 AWG Silver ETFE Mil spec Wire $25.00 Time Remaining: 23d 5h 7m Buy It Now for only: $25.00 Buy It Now

Nerve Audio Silver Spade Plugs 10 12 AWG set of 4 $9.99 Time Remaining: 3d 14h 20m

25 feet stranded 28 AWG Silver Teflon Wire Violet $4.75 Time Remaining: 22d 17h 12m Buy It Now for only: $4.75 Buy It Now

AWG20 08MM Solid Core UPOCC SILVER Audio BARE WIRE 10M $69.99 Time Remaining: 1d 17h 53m

100 ft 16 Gauge SPEAKER WIRE GA Car or Home Audio AWG Blue and Silver $12.67 Time Remaining: 19d 12h 44m Buy It Now for only: $12.67 Buy It Now

25 feet 20 AWG Silver Teflon Wire Black 19 strands $6.65 Time Remaining: 23d 14h 40m Buy It Now for only: $6.65 Buy It Now

Teflon High Temperature 16AWG Silver Plated Copper Wire M16878 4 BJE 1 1100feet $103.50 (2 Bids) Time Remaining: 3d 13h 4m

25 26 AWG stranded Silver Teflon Wire Red 19 strand $5.45 Time Remaining: 1d 7h 57m Buy It Now for only: $5.45 Buy It Now

Audioquest DV 1 DVI D Digital Video 45m 149 25 Silver 22 AWG DVI D cable $15.00 Time Remaining: 1d 17h 56m

1 PC 100 Ft Wire Wrap 30 AWG Wire Wrapping ANY COLOR Silver Plated Copper RoHS $2.79 Time Remaining: 18d 20h 19m Buy It Now for only: $2.79 Buy It Now

Audioquest DV 1 DVI D Digital Video 45m 149 25 Silver 22 AWG DVI D cable $15.00 Time Remaining: 14h 21m

25 ft 22 AWG Silver Teflon Wire White 19 strands $5.25 Time Remaining: 13d 18h 47m Buy It Now for only: $5.25 Buy It Now

25 24 AWG Teflon Silver 19 36 Strand MIL SPEC Wire $2.99 Time Remaining: 1d 18h 29m

Teflon Wire Red 18 awg Multi Stranded Hook Up UL1180 200C Gauge Silver 25ft $6.75 Time Remaining: 25d 12h 9m Buy It Now for only: $6.75 Buy It Now

25 feet 24 AWG Silver Teflon Wire Orange 19 strands 1000V $5.55 Time Remaining: 23d 9h 28m Buy It Now for only: $5.55 Buy It Now

Solid 24 AWG Silver Plated Wire Yellow Teflon 300V rated 10 Feet $2.00 Time Remaining: 1d 18h 52m Buy It Now for only: $3.00 Buy It Now

50 ft 12 Gauge SPEAKER WIRE GA Car or Home Audio AWG Blue and Silver $13.64 Time Remaining: 3d 7h 4m Buy It Now for only: $13.64 Buy It Now

Solid 24 AWG Silver Plated Wire Blue Teflon 300V rated 10 Feet $2.00 Time Remaining: 1d 18h 52m Buy It Now for only: $3.00 Buy It Now

100 ft 14 Gauge SPEAKER WIRE GA Car or Home Audio AWG Blue and Silver $14.14 Time Remaining: 19d 12h 44m Buy It Now for only: $14.14 Buy It Now

AUDIOPHILE SOLID CORE SILVER OCC BULK WIRE 30FT 22AWG $17.00 Time Remaining: 6d 12h 18m

25 feet 24 AWG Silver Teflon Wire Black 19 strands 1000V $5.55 Time Remaining: 23d 9h 25m Buy It Now for only: $5.55 Buy It Now

AUDIOPHILE SOLID CORE SILVER OCC BULK WIRE 60FT 24AWG $15.00 Time Remaining: 6d 12h 18m

100 FT 14 AWG GAUGE ZIP WIRE BLUE SILVER STRANDED SPEAKER POWER GROUND $20.85 Time Remaining: 4d 9h 39m Buy It Now for only: $20.85 Buy It Now

AUDIOPHILE SOLID CORE SILVER OCC BULK WIRE 90FT 26AWG $17.00 Time Remaining: 6d 12h 18m

25 feet 18 AWG Silver Teflon Wire Red 19 strand $10.05 Time Remaining: 1d 7h 40m Buy It Now for only: $10.05 Buy It Now

25 feet 22 AWG Silver Teflon Wire White Solid 1 Strand $9.95 Time Remaining: 1d 7h 27m Buy It Now for only: $9.95 Buy It Now

100 foot Teflon 18 awg mil spec wire silver plater copper conductor $9.90 Time Remaining: 6d 10h 12m Buy It Now for only: $16.00 Buy It Now

10 PCS 100 Ft Wire Wrap 30 AWG Wire Wrapping 10 Colors Silver Plated Copper RoHS $25.85 Time Remaining: 10d 3h 13m Buy It Now for only: $25.85 Buy It Now

25 20 AWG Teflon Silver 19 Strand MIL SPEC Wire $2.99 Time Remaining: 3d 19h 37m

200 ft 14 Gauge SPEAKER WIRE GA Car or Home Audio AWG Blue and Silver $25.89 Time Remaining: 19d 12h 44m Buy It Now for only: $25.89 Buy It Now

AWG20 08MM Solid Core UPOCC SILVER Audio BARE WIRE 10M $69.99 Time Remaining: 2d 3h 31m

10 20 AWG Shielded Silver Teflon Wire Twisted Pair $11.35 Time Remaining: 3d 4h 55m Buy It Now for only: $11.35 Buy It Now

AWG20 08MM Solid Core UPOCC SILVER Audio BARE WIRE 20M $139.99 Time Remaining: 2d 16h 56m

25 feet stranded 28 AWG Silver Teflon Wire White Red $4.75 Time Remaining: 22d 17h 5m Buy It Now for only: $4.75 Buy It Now

USB 2.0 A Male to B Male 28/24AWG Cable - 15FT(CLEAR/SILVER) List Price: $4.69 Sale Price: $3.85 You save: $0.84 (18%)   Eligible for free shipping! Availability: Usually ships in 24 hours See Reviews For This Product Description Product DescriptionLatest USB version 2.0 specification, supports the new High Speed data rates of the latest USB 2.0 peripheral devices! And is also fully compatible with all earlier USB devices. Brand-new! Fully Guaranteed! Use with both PC and Apple systems! 15 foot length, great for external drives, printer, scanner, CDRW, etc! High quality, standard A-to-B, Male-to-Male cable with molded connectors...

StreetWires PSK04BI 4 AWG Amp Kit Blue/Silver w/Interconnect List Price: $109.99 Sale Price: $49.95 You save: $60.04 (55%)   Eligible for free shipping! Availability: Usually ships in 1-2 business days See Reviews For This Product Description StreetWires 4 Gauge Power Delivery Kits are the perfect answer for large or multiple amplifier installations. They feature everything the DIY installer needs, making the task of installing your new system quick and painless...

1000FT 8C 28 AWG Silver Satin Flat Telephone Bulk Cable Sale Price: $149.00   Eligible for free shipping! Availability: Usually ships in 1-2 business days See Reviews For This Product Description 1000FT, 8C, 28 AWG, Silver Satin Flat Telephone Bulk Cable Item NO.: 31-P8-KD 1000FT, 8C, 28 AWG, Silver Satin Flat Telephone Bulk Cable

14k White Gold Round Brilliant Cut Diamond Stud Earrings (GH, SI, 0.33 carat) List Price: $865.00 Sale Price: $499.99 You save: $365.01 (42%)   Eligible for free shipping! Availability: Usually ships in 1-2 business days See Reviews For This Product Description 14k White Gold Round Brilliant Cut Diamond Stud Earrings (G, SI, 0.33 carat)These glamorous and classical diamond stud earrings are beautifully rendered in precious 14k gold with sparkling icy white Round Brilliant Cut diamonds...

Cmple - Phone Cable FLAT 6 Wire, Solid, Silver - 1000ft, 26AWG Sale Price: $61.49   Eligible for free shipping! Availability: Usually ships in 1-2 business days See Reviews For This Product Description FLAT 6 Wire, Solid, Silver - 1000ft, 26AWG Allows you to connect your telephones, faxes, answering machines, and most modems. Perfect for all your custom installation projects. 1000ft Roll Bulk Phone Cable Flat Cable Silver Color 6 Conductor AWG Solid Copper UL Listed

MRWS16 16 AWG Silver Wire Set Blue Black Red 180cm Sale Price: $8.25   Eligible for free shipping! Availability: Usually ships in 2-3 business days See Reviews For This Product Description This is the Red, Blue and Black set of 16 AWG Wire from Muchmore Racing. / / FEATURES: Ideal for battery leads, motor leads and more / Three sections of silver colored 16 AWG strand wire with vinyl / insulation / / INCLUDES: One each (60cm) section of Red, Blue and Black 16 AWG Wire from / Muchmore Racing / / REQUIRES: Wire cutter and stripper such as HCAR0635 / / SPECS: Length: 35...

Nickel Silver Wire, CDA 752, 1lb Spool, 18 AWG, 0.0403" Diameter, 204' Length Sale Price: $31.47   Eligible for free shipping! Availability: Usually ships in 24 hours See Reviews For This Product Description Nickel Silver Wire (German Silver) C75200 ASTM 206 Nickel Silver is a name applied to an alloy of copper, nickel, and zinc. The very early nickel silvers actually contained small amounts of silver. We carry the most common alloy nickel silver C75200 which nominally contains 65% copper, 18% nickel, and 17% zinc and is referred to as nickel silver 65-18...

ViaBlue SC-4 Silver-Series 8AWG Speaker Cables with Ferrite Core Filters - 3.0 Meter - Made In Germany Sale Price: $341.00 See Reviews For This Product Description High-End Silvered Speaker Cable with 896 Fine WiresViaBlueTM SC-4 Silver-Series speaker cables have silver-plated strands for the treble range and tin-plated strands for powerful playback of the bass range...

Pure Silver Wire 9999 (NOT 999) 12 Gauge 1 Ounce 36 inches Sale Price: $55.00   Eligible for free shipping! Availability: Usually ships in 1-2 business days See Reviews For This Product Description Ideal for making collodial silver. One ounce is 36 inches in length. If your intention is to make jewelry you do not need this level of purity. However, if you intend to end up putting something in or on your body, going for the highest level of purity (ten times) is obviously important...

Casio Men's AWG100-1A G-Shock Multi-Band Solar Atomic Analog Watch List Price: $130.00 Sale Price: $89.75 You save: $40.25 (31%)   Eligible for free shipping! Availability: Usually ships in 24 hours See Reviews For This Product Description The Casio Men's G-Shock Multi-Band Atomic Solar Analog Watch #AWG100-1A features a dramatic black dial face, which comes encased by a sturdy mineral dial window. Embellishing the face, stand-out indexes bring at-a-glance readability while a day-date-and-month calendar, a daily alarm, and a countdown timer enhance your timekeeping experience...