After reading, here and there, about the importance of using quality audio cable to interconnect our devices (analog signal), I'm a little confused. I don't believe the differences between cables are so important, but...

How can I test if a cable it's better than another one?

Thank you

In my experience, the most important factor in whether analog interconnects affect the "sound quality" is what equipment is on either end of the interconnect. With well designed low impedance outputs and medium-high impedance inputs, the type of cable used will probably have very little effect if it is reasonably good quality (not necessarily expensive). The longer the interconnect length, the more critical the characteristics of the cable become because this means factors like cable capacitance or inductance can become large enough to interact with the source and destination impedance to have an effect at audio frequencies.

Without some sophisticated test equipment, the only way to "test" cables is to listen for things like the low bass response, high treble response, and "harshness" in the mid-range frequencies. The real trick is to perform these tests in a way that is repeatable and does not introduce other factors that may influence the results more than the cable.

If possible, you can make a recording with each set of cables, and then play them back the same way through the same software using something like a solo function in recording software to switch between the two files. Depending on what equipment you want to connect with the cables, making a recording of the results may be difficult or impossible. For example- if you want to test the cables you would use to feed a power amp; the only way to test it is to listen to the playback through speakers, turn the amp "off' or at least the amplifiers level controls all the way down, and change the cables to complete the listening test. If you do not get the levels back to within less than 1 dB of the level used in the initial listening test, you level difference may have more effect that the cables; making the test results questionable (at best).

I would say that if you do not hear an improvement using a different cable, spend you money on other "weak links" in your system first. This will probably result in a larger improvement to the final results than spending a lot of money on expensive cables. In many cases, I have found that the only difference that expensive cables make is that they can actually degrade the sound.

The one big exception to this is speaker cables, because the source and load impedance are so close to that of the cable. This is an un-avoidable reality because all cable has some finite impedance and speakers are typically 4-6 Ohms at the low-point of their impedance response. The best way to address this is to keep the speaker cables as short as is practically possible.

Brad Johnson
Lavry Engineering Technical Support

Very grateful