Why can't new equipment play old material

[ssully]

Any QS or RM decoder will do the job.

I suspect those are rarer than used AVRs with DPLII.

 

[ssully]

I've made that comparison. My other receiver, a Marantz with PL II, with the SM connected via multichannel inputs, made that A-B comparison easy. The PL II decoder, in the receiver, was able to place sounds in the correct speakers. I used a test CD for this. When I did the same test with the SM switched in, again, the test signals were correctly placed, but with less bleed into the other channels. The Involve 5.1 mode was selected. When I played a laserdisc movie, again through the SM, you'd have a hard time distinguishing it from discrete.

what mode did you select in your Marantz DPL II decoder? IIRC there was a mode specifically for legacy Dolby
i.e., a mode that was NOT DPLII music/movie.

An original Dolby Surround 4ch soundtrack has a format : LCR/S (three front channels,1 mono surround)> So the 'correct' decode would have the same content in both surrounds. All four channels should be as 'discrete' as the encoders made them.

 

[ssully]

Yeah right. It's hard enough finding a new one that fits my requirements, chances of finding a good condition used one that fits them are close to zero. And when things need repair, in the current world where there are no repair shops worth a damn, what do you do? In 10 years AVRs with DPLII will be at least 15 years old.

your requirements are....extensive

 

[jaybird100]

I suspect those are rarer than used AVRs with DPLII.

The Surround Master, in the Involve mode, does it, and with excellent separation.

 

[ssully]

Sigh. An SM (~700 US) costs more than a used AVR , and has no HDMI connectivity. I'm quite confident SMs are rarer than used DPLII AVRs, too.

 

[Owen Smith]

your requirements are....extensive

There was a time about 20 years ago when almost every AVR met them. I don't consider them unreasonable, or actually that extensive.

Note there are a load of AVR features that many people consider essential but I don't. In particular bass management, I don't use it having full range speakers.

 

[jaybird100]

Sigh. An SM (~700 US) costs more than a used AVR , and has no HDMI connectivity. I'm quite confident SMs are rarer than used DPLII AVRs, too.

Maybe... but much more readily available!

 

[Electric Moo]

Maybe... but much more readily available!

Yes, and they are brand new. So probably good for another 30 years at least. Beats buying & restoring ancient quad gear: likely cheaper too.

 

[barfle]

Sigh. An SM (~700 US) costs more than a used AVR , and has no HDMI connectivity. I'm quite confident SMs are rarer than used DPLII AVRs, too.

Surround Masters are available from the manufacturer. I don’t know if that means they have stock that’s greater than the random ebay seller or not, but “rare” isn’t an issue with them. I purchased a new one about a month ago.

 

[MidiMagic]

what mode did you select in your Marantz DPL II decoder? IIRC there was a mode specifically for legacy Dolby
i.e., a mode that was NOT DPLII music/movie.

An original Dolby Surround 4ch soundtrack has a format : LCR/S (three front channels,1 mono surround)> So the 'correct' decode would have the same content in both surrounds. All four channels should be as 'discrete' as the encoders made them.

The correct decode can use any regular matrix decoder with the speakers placed where the decoder says to place them. But to get all of the correct decode, you need a delayed L-R channel (alone or with the matrix decoder backs) placed at center back to remove the cogging.

 

[Sonik Wiz]

The correct decode can use any regular matrix decoder with the speakers placed where the decoder says to place them. But to get all of the correct decode, you need a delayed L-R channel (alone or with the matrix decoder backs) placed at center back to remove the cogging.

In the early days of home video & Dolby surround, they struggled with how to keep the main dialog & primary effects "up front" while adding ambient & secondary effects to the rears. With out any good seperation enhancemnts they relied on the Hass or Precedance Effect. The delay in the rear chs accomplished this. It had nothing to do with cogging.

 

[Sonik Wiz]

Why do you call it a non-issue? It is quite annoying to me when it happens.

What I want to know is why most of you don't seem to hear this effect.

I am sure it's an issue to you as you as you make that clear. But based on the prodigious amount of prior discussion on this topic, it's seems it's not an issue to anyone commenting on it except you.

In discrete surround if a sound is dynamically panned Lb>Lf, or from Lf>Rf and correct mixing of -3dB at the center point will eliminate any jumping from one speaker to the next. Perhaps in the early days of mixing quad this wasn't really adhered to?

In matrix decoding the decoder should be constant power and apply a -3dB loss to the pair of speakers when a sound is centered there by allowing smooth movement in dynamic panning. The Surround Master does & I've bench tested this myself. A sound panned Lf > Rf will be -3dB at center front there by keeping the power constant and no "cogging". The action holds true for side pans front/back.

A couple of months ago I happened across a Nova episode on PBS called Perception Deception. It has to do with how our 5 senses respond to external stimuli and how the brain interprets it. Quite a bit of the 60 min eps has to do with visual perception but about about the middle they get around to auditory interpretations. The most telling line about this section is : "we hear what we expect to hear." I would say you expect to hear "cogging" and the rest of us don't and so that is the difference.

It's a fascinating show, I hope some will take the time to watch it:

 

[Owen Smith]

It's a fascinating show, I hope some will take the time to watch it:

Alas unavailable in the UK, it sounds quite interesting.

 

[par4ken]

I am sure it's an issue to you as you as you make that clear. But based on the prodigious amount of prior discussion on this topic, it's seems it's not an issue to anyone commenting on it except you.

In discrete surround if a sound is dynamically panned Lb>Lf, or from Lf>Rf and correct mixing of -3dB at the center point will eliminate any jumping from one speaker to the next. Perhaps in the early days of mixing quad this wasn't really adhered to?

In matrix decoding the decoder should be constant power and apply a -3dB loss to the pair of speakers when a sound is centered there by allowing smooth movement in dynamic panning. The Surround Master does & I've bench tested this myself. A sound panned Lf > Rf will be -3dB at center front there by keeping the power constant and no "cogging". The action holds true for side pans front/back.

A couple of months ago I happened across a Nova episode on PBS called Perception Deception. It has to do with how our 5 senses respond to external stimuli and how the brain interprets it. Quite a bit of the 60 min eps has to do with visual perception but about about the middle they get around to auditory interpretations. The most telling line about this section is : "we hear what we expect to hear." I would say you expect to hear "cogging" and the rest of us don't and so that is the difference.

It's a fascinating show, I hope some will take the time to watch it:

I agree with you Sonic but still I understand what Midi is saying, it's just that I don't think that it is much of an issue. PWM works best left to right, front to rear not as well (some say not at all). Simply by placing the rear speakers to the sides (rather than behind) you can hear near perfect pans without the so called "cogging" effect. Do I move my head while listening to such pans, maybe but not consciously. It would be more unnatural to sit in one spot motionless.

They made the right decision when they designed SQ. Left to right separation is the most important. Front to rear with only a slight level difference will help snap the image to the front or to the back (assuming that cogging is a real thing). Side imaging is less important IMHO.

Hole in the middle stereo is what you get when the speakers are moved too far apart. The same goes (only more so) for surround with front to rear speakers placed too far apart. With my Living Room system the back speakers are positioned rather far from the front (was not my choice). Still both discrete, stereo enhanced and matrix sound fine to me. I seldom sit in the sweet spot either.

Midi, you should be using Ambisonics. That is the only system that images "properly" all around. My Troy (automotive) decoder works well when listening via the small speakers surrounding my workbench, it images where there are no speakers. Sadly not much program material is available. I don't find the "Super Stereo" mode of the Troy to be very effective however.

 

[MidiMagic]

In the early days of home video & Dolby surround, they struggled with how to keep the main dialog & primary effects "up front" while adding ambient & secondary effects to the rears. With out any good seperation enhancemnts they relied on the Hass or Precedance Effect. The delay in the rear chs accomplished this. It had nothing to do with cogging.

But it does remove the cogging effect. This was not intended, but a useful side-effect. The fact is, it does work. It provides the missing delayed Hass sounds necessary to hear sounds between the speakers on either side.

I tested this using my mixer-encoder and two decoders:
- A basic speaker RM with adjustable front and back separation.
- A Dolby Surround Pro Logic I decoder.

I heard the cogging when panning forward and back on either side with the RM matrix. When I was facing forward, the sound suddenly jumped between front and back speakers as I turned the pan control.

There was no cogging with the Dolby Surround. When I was facing straight ahead, I heard no interruptions in the panning forward and back on either side.