HD-1 Processing

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ai4i
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HD-1 Processing

Post by ai4i » Tue Jan 04, 2011 6:58 pm

Two schools of thought on this.
Set the HD-1 to perfectly match the analog in every way or set it to match the analog in time, and peak volume.
We hate to hear a station fade between analog and HD with no improvement:
the same roll off to 15 KHz and the same heavy processing even though there is no noise floor with which to compete (the original purpose of compression).
HD-1's should have a "wow" factor but having them sound exactly as the analog, they could be promoted as, "get a radio with HD technology, we promise it will sound every bit as good as the radio you have now"
We are unimpressed with the former school of thought.
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Re: HD-1 Processing

Post by Deep Thought » Tue Jan 04, 2011 7:40 pm

As much as I agree with you when it comes to providing the best possible audio quality, audio processing has been all about 'sound signature' since before the first Optimod, arguably all the way back into the AM Top-40 heyday. Plus, automotive listening still has a very high noise floor in most cars. You have to take this into consideration.
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Re: HD-1 Processing

Post by BroadcastDoc » Tue Jan 04, 2011 7:46 pm

There were some studies done a while back that showed that many listeners didn't like the way it sounded in fringe areas when the radios would roll back and forth from 15kHz audio to 20kHz audio. Many mentioned that it was "jarring" and that they felt (mostly psychologically) they had to adjust the volume. It was so prevalent that it was suggested that you roll off your digital signal at 15-16kHz.

The "wow" factor is there at first, but in mobile environments it gets pretty annoying. If you notice, nobody promotes audio quality as a selling point to HD anymore - it's all about additional content. Of course if you're running additional content, good luck getting that 20kHz to sound any good! :)

Bottom line is that reality tells us that a good portion of our audience really doesn't care about "near CD quality" - if you listen to what passes for audio on iPods these days, you'd know what I'm talking about - rather they care about content. It's the additional channels that are slowly moving the needle.
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Re: HD-1 Processing

Post by ai4i » Tue Jan 04, 2011 9:38 pm

What it seems to come down to is that the best sounding streams will be the HD2's on stations that only run a main and a 2.
We have some great sounding 2's where I live, at least compared with standard FM, although I love to hear a station (second school of thought) pop from analog into brilliant HD1...wow!
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Re: HD-1 Processing

Post by BroadcastDoc » Wed Jan 05, 2011 1:52 pm

Many moons ago, when I first lit up my HD's (before we were allowed to multi-cast) I ran them with very little processing. They sounded PHENOMENAL! Really unbelievable. Even an HD with one sub-channel can be made to sound pretty good.

I think the key is that the Engineer really needs to process the audio properly. I've heard stations that have no sub-channels sound awful, and I've heard stations with two sub-channels that sound great. It all boils down to taking the time and spending the money to do it properly.
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Re: HD-1 Processing

Post by NECRAT » Wed Jan 05, 2011 2:21 pm

BroadcastDoc wrote:Many moons ago, when I first lit up my HD's (before we were allowed to multi-cast) I ran them with very little processing. They sounded PHENOMENAL! Really unbelievable. Even an HD with one sub-channel can be made to sound pretty good.

I think the key is that the Engineer really needs to process the audio properly. I've heard stations that have no sub-channels sound awful, and I've heard stations with two sub-channels that sound great. It all boils down to taking the time and spending the money to do it properly.
And it's amazing when the engineer doesn't. I can listen to both great HD and horrible HD from my bench here at home. It really is amazing. The best sound HD stations around here are the local Clear Channel ones. The chief there, has an excellent ear for processing and has them done right.
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Re: HD-1 Processing

Post by Chris from Milwaukee » Fri Jan 07, 2011 12:22 am

I must be an odd ball because I can always hear the improvement in the audio quality in my vehicles. Without looking at the display (and my eyesight is so bad that I really can't while driving) I can tell whether a station is in analog mode or digital. I definitely like the digital sound better. When it comes to fringe reception areas which I seem to be in a lot these days, the back and forth can be a little distracting. On AM it is downright annoying.

The additional content is a big seller for me.
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Re: HD-1 Processing

Post by ai4i » Sun Jan 23, 2011 7:50 pm

Chris from Milwaukee wrote:I must be an odd ball because I can always hear the improvement in the audio quality in my vehicles.
Well, the noise floor (picket fencing) drops to zero
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