XLR vs. RCA

[swayback]

I have B&W 804's. Any one have an opinion on XLR versus RCA cables in preamp to amp?

thanks.

[Kal Rubinson]

It would provide more relevant information if you told us what preamp and amp you are connecting.

[swayback]

804Di
Integra DHC 80.1 PreAmp
Integra DTA 70.1 Amplifier

[Kal Rubinson]

It should not matter at all unless the amp and preamp are separated by long distances (measured in 10s of meters) or you have a very EM noisy environment. Otherwise, the only distinction is the more positive latching of the XLRs.

The 804Di is irrelevant to this issue.

[Hdale85]

If they are truly balanced designs you do get a bit more gain and a lower noise floor. Weather it's audible to you or not who knows. But really even if you could tell it probably wouldn't be a very big difference.

[swayback]

It should not matter at all unless the amp and preamp are separated by long distances (measured in 10s of meters) or you have a very EM noisy environment. Otherwise, the only distinction is the more positive latching of the XLRs.

The 804Di is irrelevant to this issue.

Thank you for your input.
The reason I put the name of the speakers is because this actually started in the B&W forum, until it was moved to Home Theater.

[Space]

Try it both ways--balanced vs. unbalanced--and report back if there's a clear difference. It could be that balanced is better at rejecting noise, but that's not going to matter if there's no noticeable noise to begin with from unbalanced cables.

[wettou]

XLR wins hands down especially to avoid EMI/RFI

[Nolan B]

XLR wins hands down especially to avoid EMI/RFI

BS IMO.

XLR does nothing over RCA. You would have to do extremely long distances between your amp and SSP before you could scientifically measure a difference. I would go as far as saying that you could go 500 feet between the the SSP and amp before you would even have the possibility of measuring a difference.

My SSP and amp is balanced and I use XLR. Why? Looks...nothing else.


If you are looking to improve audio quality look at room treatments before anything else.

[Hdale85]

Well if you have a lot of RF/EMI noise in your area the XLR will make a difference regardless. And I'm not so sure about 500 feet. RCA connections are low voltage and after so far of a distance they start to suffer from loss.

[Burke Strickland]

The XLR connection is essential when your kids are playing skip-rope with especially long interconnects so the cables will not spontaneously disconnect, as the RCAs are prone to do, which would create a tripping hazard during thier game, to say nothing of the danger of a flying cable end. :>) More seriously, as for the sound, other than needing to reset the volume, I have not heard a significant audible difference between XLR and RCA connections using comparable quality cables on my 15 foot run between Bryston SP-2 pre/pro and Bryston 7B SST power amps. But the XLR connections do "stay put" and "look professional".

[whoaru99]

RCA connections are low voltage and after so far of a distance they start to suffer from loss.

Not very much or, perhaps, depends on the nature of the loss you're talking about.

For example...

In my bedroom system I have a Proceed PRE preamp connected to a Yamaha M-80 power amp. The Proceed PRE output impedance is given as less than 20 ohms and the Yamaha amp input impedance is given as 20,000 ohms.

For sake of the discussion, let's say I was using 500ft long interconnect made from 24ga pair of wires. 1000ft of 24ga has resistance of about 26 ohms. The total output impedance is that of the preamp plus interconnect so roughly 46 ohms and, again, the amp input impedance is 20,000 ohms.

This results in signal voltage loss of 0.02dB in this example. Put another way, if the preamp output was 1 volt, the amplifer would see ~0.9977 volt at its input, a loss of 0.0023V

Yes, there is some loss suffered, but very, very, very small amount. There are other factors that may serve to degrade the sound but signal voltage loss, per se, isn't much to speak of.

[wettou]

BS IMO.XLR does nothing over RCA. You would have to do extremely long distances between your amp and SSP before you could scientifically measure a difference. I would go as far as saying that you could go 500 feet between the the SSP and amp before you would even have the possibility of measuring a difference.

So please explain to me why all recording studios use only balanced connections

If you are looking to improve audio quality look at room treatments before anything else.

Agreed you room is equal to 50% of the sound unless you are like me and sit less than five feet away from the speakers when listening closely. :T

Cables are last on the list

[Burke Strickland]

...unless you are like me and sit less than five feet away from the speakers when listening closely.

That's listening closely, alright. :>)

[chrispy35]

Not very much or, perhaps, depends on the nature of the loss you're talking about.

For example...

In my bedroom system I have a Proceed PRE preamp connected to a Yamaha M-80 power amp. The Proceed PRE output impedance is given as less than 20 ohms and the Yamaha amp input impedance is given as 20,000 ohms.

For sake of the discussion, let's say I was using 500ft long interconnect made from 24ga pair of wires. 1000ft of 24ga has resistance of about 26 ohms. The total output impedance is that of the preamp plus interconnect so roughly 46 ohms and, again, the amp input impedance is 20,000 ohms.

This results in signal voltage loss of 0.02dB in this example. Put another way, if the preamp output was 1 volt, the amplifer would see ~0.9977 volt at its input, a loss of 0.0023V

Yes, there is some loss suffered, but very, very, very small amount. There are other factors that may serve to degrade the sound but signal voltage loss, per se, isn't much to speak of.

Your example is only accurate for DC which is not what we are worried about for audio. The longer cable run will result in higher inductance in the circuit which, after a point, should introduce some low-pass filtering. How long of a cable you need to have before that becomes audible is another equation.