signal-to-noise ratio, what is best?

[lordsmurf]

When I read something like "" signal-to-noise ratio (68dB) "" is this a good thing or a bad thing?

Is having the SNR increased good? Or is decreased better?

I'm looking at a review of a product. It said the new one has an increased SNR. So.... is that good?

BJ_M, hope you're reading this. I think you'll have a good answer.

[samijubal]

A higher signal-to-noise ratio would be better, that would mean less distortion.

[Jester700]

A higher signal-to-noise ratio would be better, that would mean less distortion.

Technically, yeah, since anything not part of the original signal is a kind of distortion. But this is misleading, since people think of "distortion" as harmonic distortion - basically "fuzz". Noise is generally considered as white or pink noise - "hiss" - like a radio tuned between stations.

And yeah, higher is better. 68dB is pretty poor these days...

[johns0]

Think of cassette tape hiss,the snr is about 40db,when dolby c is used the snr is about 75db.

[lordsmurf]

Analogy helped!

But I am looking at a video-only device, no audio.

Sort of wading through unknown territory here.

[johns0]

Here`s a more detailed explanation of electronic SNR than i could explain

[gshelley61]

Video signal to noise ratios in most equipment range from below 50dB to over 70db (the higher the better). VHS has a much lower S/N ratio than MiniDV, for example. That's why VHS is visibly "noisy".

When sending video signals through several devices, using quality equipment with high S/N ratios helps to prevent video noise from compounding too much as the signal goes trhough each piece of gear.

Remember that printed video specs can be misleading, just like in the audio world.

[FOO]

A signal / noise ratio of 68 dB is 2512 to 1
or the noise is about 0.04 % of the signal.

Definitely the higher the better , ... unless you want noise.

[Jester700]

I assume you guys know this, but in case anyone reading doesn't...

Video noise is seen as "snow" or "grain" in the picture; better gear will add less of it.

And yeah, audio noise is hiss - sorry I didn't catch your meaning earlier, smurf...

[deckard8]

S/N ratio dB S/N ratio:1 Picture quality

60 dB 1,000 Excellent, no noise apparent
50 dB 316 Good, small noise, qual good.
40 dB 100 Reasonable, fine grain/snow.
30 dB 32 Poor pic. great deal of noise.
20 dB 10 Unusable picture.