37 replies to this topic

[davesmith]

hey guys i just purchase 3 amps for my car, which im changing into a SQ car how much should i be spending on RCA's i did a bit of research and i found some RCA cable that cost $14k a meter ( http://warco.com.au/waraudio/index.html go to oyaide elec under accessories) total crap i think, but how much should i spend on cable and if i were to buy coax cable from altronics and made them myself whould that be sufficiant to run two u dimension 20vs and a u dimension 2k comp?

[bob]

As long as purist audiophiles exist, there will be a market for stupidly over-priced RCA leads.
Some cable from Altronics, coupled with some of their decent quality RCA terminals will be ample.

[ProClass]

There are some very strong and understandable design concepts in thier cable designs. Spending 14K a meter is well and truely out of my budget and I am sure that the rest of my gear would very reproduce any improvement this cable brings to my design.
Having said that, there are some very good reasons to use good quality RCA cables.
How mcuh should you spend? I would be more than happy with the quality of a cable costing $20 per meter and $60 for connectors. More if budget permits.
Cheers

[abmolech]

Quote

The main limiter on an RCA cable is the terminators (The plugs) I recommend canare.

On threads such as this I have set down the challenge.

Beat 75 ohm coaxial cable. ($1.50 per metre, plus terminators.)

The challenge?

Replace that cheap coaxial cable carrying MHz (Not the minor up to 20 KHz of an ordinary audio cable) with those "fancy" twisted pair, or those expensive RCA coaxial.

Where?

Your antenna cable, going through the "noise capital" of your car (the dash)



Guess what?

No-one has been STUPID enough to try.

Perhaps easier, replace the monitor cable (coaxial with 75 ohm terminators) with one of those "fancy" cables. Watch the picture....



Point

75 ohm coaxial cable and terminators will EAT twisted pair, and those expensive cables alive. Better for carrying signal, better for noise rejection.

Disagree?

Take the challenge.

Watches as the cable merchants run for cover.

Quote from another thread.



Please, pretty please, with ice cream and cherries on top, take the challenge.

[Pulse-R]

wtf abmolech???

since when is 75ohm radio cable gonna make better audio?
we all know that, at audio frequencies, it's a lot of the cross-sectional area that makes the difference in the bottom end, and the stranded construction that work in the upper... materials used and overall build quality and consistency of the cable is what makes a good cable.

I've tried cheap 75ohm coax and it stinks for audio.

[abmolech]

You miss the points



First point

If twisted pair etc are so good at noise rejection, then they should be better for antenna cable. (Goes through the noisiest part of the car, the dash)

Second point

If they are so superior at carrying audio signals than 75 ohm coaxial, then they should be better than 75 ohm at carrying MHz, unless of coarse you think 20 Hz to 20 KHz is much harder to carry than MHz?



Yep didn't think so.



Take the test, unless you know that 75 ohm cable is going to set the standard.

[Luke352]

What about this stuff Abmolech, I've got quite a bit of this M17 Twinax cable lying around and have always wondered whether it would be worthwhile trying out as an RCA.

http://wireandcable.thermaxcdt.com/item/hi...9-?&seo=110

http://www.greenwood-electronics.co.uk/Cab...riaxQuadrax.asp

Luke

[abmolech]

Should be fine Luke.

Quote

we all know that, at audio frequencies, it's a lot of the cross-sectional area that makes the difference in the bottom end, and the stranded construction that work in the upper... materials used and overall build quality and consistency of the cable is what makes a good cable.

I've tried cheap 75 ohm coax and it stinks for audio.

A cable is a simply defined by RLC network.

Its like using a 12 gauge and comparing it to 01 gauge wire at 1 metre length to carry 100 amps at 12 volts DC duty cycle.

Point

The 75 ohm coaxial with genuine 75 ohm terminators is over built for the job of handling audio frequencies, it can transfer MHz through the noisiest part of your car with ease.



Since this is too technical for most to grasp, I put out a basic challenge.



Please put your superior audio cables in the antenna application, or monitor.

I note that none a prepared to take it.



Until your prepared to do so, I am going to set the BS meter to full alert.

[Sierra]

At $14,000 for 1 metre of RCA cable .... I would expect the strands to be nothing less than 24ct solid gold

[Brycestro]

abmolech - i'm assuming you use the 75 ohm coax cable rather than twisted pair in your own car? Genuine question, not being a smartass. What's the diameter of coax cable like compared to RCA? I've got a mental image of a big fat antenna cable like the one plugging into my television, but i could be thinking wrong?

[DeeCee]

It will make an SPL car blush with the amount of cable run through the car Brycestro

[abmolech]

Hi Brycestro,

Yes I use 75 ohm cable, with genuine 75 ohm terminators (canare)



RG60 is 8 mm diameter, probably the one your thinking of.

RG59 is 6 mm diameter



Like most cable you can get solid core or multi-strand. Multi -strand is easier to bend around corners etc.



It is "industry standard", so you know it is tried and proven. Any 75 ohm cable is over rated for the job.



With most terminators (I would guess even the $14000) have terminators that can only exhibit 20 ohms impedance. So a 75 ohm cable is well above specification.

A 50 ohm is more than adequate.

But for MHz you need a minimum of 75 ohms impedance, think radio and TV antenna, and monitor cables. For cables designed to this, 20-20 kHz is like "falling off a log".



You note NONE of these guys (cable merchants) will take the test.



Thats why 75 ohm coaxial cable is the STANDARD, which all other have got to meet or exceed. I could take the time to explain, resistance, inductance and capacitance (RLC) but this never gets anywhere.

[ProClass]

abmolech, on Sep 3 2007, 02:35 PM, said:

Hi Brycestro,

Thats why 75 ohm coaxial cable is the STANDARD, which all other have got to meet or exceed. I could take the time to explain, resistance, inductance and capacitance (RLC) but this never gets anywhere.

And why is that?
hmmm

[abmolech]

Because it has to meet or exceed industry standards (specifications).

What standards or specifications do the cable merchants meet? :clapping:

[Big_Valven]

I agree - totally and wholeheartedly - cables in general are extremely overrated especially in car sound. If the basic requirements are met (ohms/metre, uF/metre, uH/metre, voltage/current rating, signal bandwidth) then the cable will carry the signal with absolute minimal affect on the signal. Unfortunately all cables have resistance, capacitance and inductance so there is no escaping the inevitable.

There is still careful consideration needed to select the right cable for your needs, but it is not purely a $$$/result relationship.

All of the people who push those high-cost cables with exotic names, "technology," and price tags, NEVER mention these vital specs. However, look at any quality cable brand (canare comes to mind) and you can always track down the specs that matter.