CD Upsampling!

[liberalz]

I use my DVD player, 95%, for listening to music CD. Yamaha has the the following options

1. Off
2. 88 "x2"
3. 176 "x4"

Does these settings applicable if I'm sending the signals through digital connection (optical) to my AVR.

Cheers.

 

[MDS]

Yes, they are applicable over the optical connection.

The question is whether or not there is anything to be gained by upsampling and the answer is generally No.

CDs use a 44.1 kHz sampling frequency, so 88.2 is twice oversampling and 176.4 if 4 times oversampling. There are a few different upsampling algorithms that could range from as simple as duplicating every sample for 2x upsampling or quadrupling every sample for 4x upsampling to interpolating (sophisticated guessing) values between samples. Either way it is adding information that didn't previously exist.

Upsampling does shift quantization noise to higher frequencies beyond the range of human hearing (44.1 kHz for 2x and 88.2 kHz for 4x) but you won't hear much if any difference as the Nyquist frequency for 44.1 kHz (22.05 kHz) is already above human hearing. At best the higher frequencies near 20 kHz may sound a teeny bit clearer - assuming you are under age 20 and can hear that high anyway. [The vast majority of adults can't hear much at all beyond 16 kHz).

 

[mtrycrafts]

Yes, they are applicable over the optical connection.

The question is whether or not there is anything to be gained by upsampling and the answer is generally No.

CDs use a 44.1 kHz sampling frequency, so 88.2 is twice oversampling and 176.4 if 4 times oversampling. There are a few different upsampling algorithms that could range from as simple as duplicating every sample for 2x upsampling or quadrupling every sample for 4x upsampling to interpolating (sophisticated guessing) values between samples. Either way it is adding information that didn't previously exist.

Upsampling does shift quantization noise to higher frequencies beyond the range of human hearing (44.1 kHz for 2x and 88.2 kHz for 4x) but you won't hear much if any difference as the Nyquist frequency for 44.1 kHz (22.05 kHz) is already above human hearing. At best the higher frequencies near 20 kHz may sound a teeny bit clearer - assuming you are under age 20 and can hear that high anyway. [The vast majority of adults can't hear much at all beyond 16 kHz).

CD players soon after the initial introduction back in ancient times started to over-sample and became a standard practice. At first this was advertised but over time the advertising disappeared. I doubt the oversampling went away.
Perhaps, the new advertising is a re-visitation of the old days, nothing more.
This helps with not needing a brick wall filter.

 

[liberalz]

Thanks MDS. Great & clear input.

 

[bryantm3]

Yes, they are applicable over the optical connection.

The question is whether or not there is anything to be gained by upsampling and the answer is generally No.

CDs use a 44.1 kHz sampling frequency, so 88.2 is twice oversampling and 176.4 if 4 times oversampling. There are a few different upsampling algorithms that could range from as simple as duplicating every sample for 2x upsampling or quadrupling every sample for 4x upsampling to interpolating (sophisticated guessing) values between samples. Either way it is adding information that didn't previously exist.

Upsampling does shift quantization noise to higher frequencies beyond the range of human hearing (44.1 kHz for 2x and 88.2 kHz for 4x) but you won't hear much if any difference as the Nyquist frequency for 44.1 kHz (22.05 kHz) is already above human hearing. At best the higher frequencies near 20 kHz may sound a teeny bit clearer - assuming you are under age 20 and can hear that high anyway. [The vast majority of adults can't hear much at all beyond 16 kHz).

my grandpa notices a very high pitched hum when he plays a CD, i suppose it's from the samples rapidly switching creates a clicking, when done that quickly creates a high frequency, and he's 79. i can hear what he's talking about, but it's only noticable to me if i really try to listen. he (and i) do not hear this when playing a record.

 

[mtrycrafts]

my grandpa notices a very high pitched hum when he plays a CD, i suppose it's from the samples rapidly switching creates a clicking,to me if i really try to listen. he (and i) do not hear this when playing a record.

No, you do not hear the sampling rate. Besides, it is ultrasonic at 44.1k. It is something else in your system.

 

[MDS]

To me it sounds like bryantm3 may be talking about the high speed PWM switching of a digital amplifier but I doubt anyone could hear that at all because the frequency is in the hundreds of megahertz.

 

[mtrycrafts]

To me it sounds like bryantm3 may be talking about the high speed PWM switching of a digital amplifier but I doubt anyone could hear that at all because the frequency is in the hundreds of megahertz.

That may be but he did say that this is apparent with CDs and not with vinyls.