Big volume change between HD and SD channels

g182237

SatelliteGuys Family
Original poster
Nov 10, 2008
48
0
Honolulu
Why is there such a big difference in volume levels whenever I change from a HD channel to a SD channels or the other way around? I have a Vip622 and it's pretty annoying, especially at night. Thanks
 
Warlock is right. Higher bit-rate audio requires more volume. If you watch a DVD on a good rcvr, then pop in a blu-ray with hd audio, the volume has to be increased by a lot. As long as its been an issue, you figure they woulda fixed the whole HD programming/SD commercial/blowing you out of the chair deal. ESPN is bad about this. I have to crank it for college football, then the commercials make me go deaf.

:mad:
 
Higher bit rates are generally the result of a program being sent with a wider (read: more accurate) dynamic range. You need the higher bandwidth to accurately reproduce very low sounds (an oboe rising from nothing in a symphony) to the crescendo of the full orchestra!

Audio that is transmitted (on the cheap) that is dynamically compressed such as SD or commercials will sound louder because the low volume items are raised and the high volume bits are lowed so that the delta change between the lowest and highest volume is much less without clipping (distortion) occuring. If its much less then you have to send much less data (sort of like a low-res 320x240 picture to a 1024x728 picture where the 1024 picture is higher resolution and therefor larger).

So the bitrate really isn't the problem if your sender (DVR), cable (HDMI 1.3, TOSLINK, etc) will take the higher bandwidth and the receiver can accept the bitrate. But because its not artificially compressed (low vol raised, high vol lowered) so that their is less headroom between the softness of the symphony to the loudest of the the same.

It's also the same why Plasma TV's look better than LCDs. They have a greater Dynamic Range contrast ratio in the order of 300,000:1 for some sets while LCD's struggle to get 60,000:1. Side by side a Plasma will have deeper blacks and whither whites next to each other while the LCD will seem washed out. Put them in different rooms and your 'relativistic' eye can't decearn difference unless they are next to each other when it's obvious.

I do a lot of audio editing on concerts, and to get a concert to fit on 1 or 2 CD's, I have to do Dynamic Range compression to get the files small enough to fit on the CD's. The good thing is that they are now relatively louder. If I didn't compress they would sound better but you would have to crank up your volume to hear Stevie Nicks in a solo and be blasted when Lindsey or Mick kick in with the guitar or drums. Besides, at full 44000kpbs/sec stereo recording you could only fit 2 - 3 songs on a single cd.

That's why it seems louder on DR compressed audio. 2 channels to 5 channels have no correlation at all to the volume. If I'm sending 200kpbs to each channel and a I have a 1Mbps pipe then I can send 200kpbs to each speaker in bit rate. But if I'm limited to 200kbps then I have to compress the audio. It's not like a splitter where you take 2 channels and split them into 5 so therefor each one will be weaker.
 
Preety good

Higher bit rates are generally the result of a program being sent with a wider (read: more accurate) dynamic range. You need the higher bandwidth to accurately reproduce very low sounds (an oboe rising from nothing in a symphony) to the crescendo of the full orchestra!

Audio that is transmitted (on the cheap) that is dynamically compressed such as SD or commercials will sound louder because the low volume items are raised and the high volume bits are lowed so that the delta change between the lowest and highest volume is much less without clipping (distortion) occuring. If its much less then you have to send much less data (sort of like a low-res 320x240 picture to a 1024x728 picture where the 1024 picture is higher resolution and therefor larger).

So the bitrate really isn't the problem if your sender (DVR), cable (HDMI 1.3, TOSLINK, etc) will take the higher bandwidth and the receiver can accept the bitrate. But because its not artificially compressed (low vol raised, high vol lowered) so that their is less headroom between the softness of the symphony to the loudest of the the same.

It's also the same why Plasma TV's look better than LCDs. They have a greater Dynamic Range contrast ratio in the order of 300,000:1 for some sets while LCD's struggle to get 60,000:1. Side by side a Plasma will have deeper blacks and whither whites next to each other while the LCD will seem washed out. Put them in different rooms and your 'relativistic' eye can't decearn difference unless they are next to each other when it's obvious.

I do a lot of audio editing on concerts, and to get a concert to fit on 1 or 2 CD's, I have to do Dynamic Range compression to get the files small enough to fit on the CD's. The good thing is that they are now relatively louder. If I didn't compress they would sound better but you would have to crank up your volume to hear Stevie Nicks in a solo and be blasted when Lindsey or Mick kick in with the guitar or drums. Besides, at full 44000kpbs/sec stereo recording you could only fit 2 - 3 songs on a single cd.

That's why it seems louder on DR compressed audio. 2 channels to 5 channels have no correlation at all to the volume. If I'm sending 200kpbs to each channel and a I have a 1Mbps pipe then I can send 200kpbs to each speaker in bit rate. But if I'm limited to 200kbps then I have to compress the audio. It's not like a splitter where you take 2 channels and split them into 5 so therefor each one will be weaker.

This is a pretty good explanation but just slightly off. In the audio here for SD it doesn't just use a compressor. It uses a comp/limiter. Which means that they have the high volume limited to as much as they can in relation to the highest volume of the show then the dynamic range is then compressed to bring the low volumes up to reduce the dynamics to a small 10 to 20 % of the natural range.
 
Agreed,

I was trying to finish up what was becoming a large post (when I wanted it to be smaller, maybe I should have compressed LOL ) just as the OSU game was coming on.

Comp/Limiter on Analog originated audio. Dynamic Range Compression on digital audio.
 
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