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Essential AES reading for high fidelity home reproduction

amirm

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What's that you are saying? Too many? It is just 5% of all the papers I have in my library :).

Hence the reason I suggested reading Dr. Toole's book. It can be a challenging read but it encapsulates many of these papers.

Over time I will be doing digests on all of these papers.
 

dallasjustice

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Since you mentioned stereo playback and subwoofers (my passion as well), I need to express the following sentiments:

1. Most of the standard subwoofer recommendations presuppose a rectangular room or similar.
2. There are computer generated subwoofer setups. I'm not talking about those here; just the standard setups.
3. There are many ways to set up subs and none of them are perfect. Bass is never perfect on paper.
3. The so called Welti four sub midwall setup is optimal if one seeks a very wide and even sweet spot. It can be best described as a mode redistribution method. IOW, the modes still exist but they are spread out and thereby greatly diminished and much less audible. This method is NOT a mode cancellation method. This method is more ideal for home theater setups where there will more than one or two listening positions.
4. The best subjective single listener, stereo subwoofer setup referenced in the Fazenda research, is a two subwoofer setup. It is referred to as a source/sink array and is described in detail in the paper. There's also a reference to earlier tests on source/sink. This IS a mode cancellation technique. I prefer to think of it as a length mode active absorption method because that's what it actually does. This method doesn't have as wide a sweet spot as #3 above. But, IMO, it's the "best" method I've encountered at removing length modes and filling in rearwall Allison effect. This is the method I use after having tried many other methods including #3 above. I rarely use my system for home theater and rarely have more than a couple of listeners. Most of the time I listen solo to stereo playback.

I hope this info helps.
I'm looking to compile a list of what people consider essential AES reading for high fidelity stereo reproduction in the home. The first I plan to start reading is the Welti subwoofer articles (thanks @dallasjustice ), but doing a search there are seven articles just on the first page of my search (with 129 total results).

This is why I'm emphasizing essential reading since my time is limited. Thanks all!

Edit: the Welti sub article that Nyal Mellor linked in one of his blog posts is this one. Nyal's site is a great resource for information. I'll continue to add links as I go through it.
 

amirm

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. The so called Welti four sub midwall setup is optimal if one seeks a very wide and even sweet spot. It can be best described as a mode redistribution method. IOW, the modes still exist but they are spread out and thereby greatly diminished and much less audible. This method is NOT a mode cancellation method. This method is more ideal for home theater setups where there will more than one or two listening positions.
Those settings do cancel modes Michael. For example by using two opposing subs, you cancel the mid-point null. Here is a good diagram from Dr. Toole's book:

upload_2017-1-15_19-6-8.png
 

tomelex

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Nice OP, hope it becomes a sticky
 

andyc56

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Edit: the Welti sub article that Nyal Mellor linked in one of his blog posts is this one. Nyal's site is a great resource for information. I'll continue to add links as I go through it.

That article PDF can be downloaded for free here.
 
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hvbias

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What's that you are saying? Too many? It is just 5% of all the papers I have in my library :).

Hence the reason I suggested reading Dr. Toole's book. It can be a challenging read but it encapsulates many of these papers.

Over time I will be doing digests on all of these papers.

Thanks Amir, I have Dr. Toole's book. I should read it cover to cover (and then do it again), I use it as a reference and pick selected topics to go through when I have time.

Subwoofers and smooth in room bass response. Optimal room dimensions (some limitations with ceiling height) are the two primary areas I'm looking to learn more about.

4. The best subjective single listener, stereo subwoofer setup referenced in the Fazenda research, is a two subwoofer setup. It is referred to as a source/sink array and is described in detail in the paper. There's also a reference to earlier tests on source/sink. This IS a mode cancellation technique. I prefer to think of it as a length mode active absorption method because that's what it actually does. This method doesn't have as wide a sweet spot as #3 above. But, IMO, it's the "best" method I've encountered at removing length modes and filling in rearwall Allison effect. This is the method I use after having tried many other methods including #3 above. I rarely use my system for home theater and rarely have more than a couple of listeners. Most of the time I listen solo to stereo playback.

I hope this info helps.

Ah yes, this is the setup that interested me. Thanks.
 
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andyc56

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Those settings do cancel modes Michael. For example by using two opposing subs, you cancel the mid-point null. Here is a good diagram from Dr. Toole's book:

[See Amir's post for diagram]

Yes. But it should be noted that said cancellation only occurs when the two (assumed identical) subs have signals to them that are equal in amplitude and in phase. If you use a system like SFM or MSO, which individually equalize the subs, this condition may be violated, making the situation a lot more complex.
 

dallasjustice

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The Welti 4 sub midwall method in a rectangular room doesn't cancel modes. You can cancel the so called mid point null or a 1st order mode using a single midwall subwoofer. A single subwoofer will only cancel a single mode when placed midwall. But when you add the other 3 midwall subs in the room, the modes are not cancelled. They are redistributed.
Those settings do cancel modes Michael. For example by using two opposing subs, you cancel the mid-point null. Here is a good diagram from Dr. Toole's book:

View attachment 5198
 
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oivavoi

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I just started reading Floyd Toole's book. I've had it on my todo-list for quite some time, but this thread reminded me again to do it. Surprisingly well-written and interesting!
 
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hvbias

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Group delay in low frequencies- any good AES papers on this?
 
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