How do you read AV grades?

[Steve81]

How about if you have to crossover high? Would this make it more easy to locate, because a small amount of midd's would go into the sub making him take the part of a center speaker?

IME, an XO of 120Hz with proper blending of the mains & sub isn't problematic for localization.

As far as actual technical papers on the subject, there is one AES paper titled "Detection of subwoofer depending on crossover frequency and spatial angle between subwoofer and main speaker" that is applicable. Some select quotes:

It was noticed that the listening panel could be divided into two groups. The selected crossover frequency range was not wide enough for half of the listeners, as at some cases they did not detect the difference between reference and split signal even at the highest crossover frequency value.

30 crossover frequency values listed in the Table 1 were used between 55 and 227 Hz

The results show also that with these sound samples the crossover frequency can be set to fcrossover ≈ 120 Hz before the subwoofer becomes detectable.

 

[Alex2507]

IME, an XO of 120Hz with proper blending of the mains & sub isn't problematic for localization.

I can find my subs at 80 Hz. I tried 60Hz to mitigate that and while that helped I still left it at 80Hz so that by turning the subs off, I kill more sound that travels in condo heaven. A 120 Hz xo is something I use for some wall mounted speakers around the tv in Mantown. There's no way for me to blend that without co-locating the sub/s and speakers. You'd think I wouldn't care with the tinnitus and all but it bugs me to no end. I understand most people share your experience but there are people out there like me.

 

[Steve81]

I can find my subs at 80 Hz. I tried 60Hz to mitigate that and while that helped I still left it at 80Hz so that by turning the subs off, I kill more sound that travels in condo heaven. A 120 Hz xo is something I use for some wall mounted speakers around the tv in Mantown. There's no way for me to blend that without co-locating the sub/s and speakers. You'd think I wouldn't care with the tinnitus and all but it bugs me to no end. I understand most people share your experience but there are people out there like me.

A few thoughts, some of which may be useful to you...

Under most circumstances, your ears have a hard time localizing deep bass simply due to the length of the sound waves involved. You can locate higher frequencies easily by virtue of having a pair of ears with some distance between them. My understanding is that as the sound waves become longer and longer (200Hz is >5 feet; 100Hz is >10 feet), even the ability to detect phase differences from one ear to another becomes spotty. In home audio, this is further reinforced by having 2 or more speakers producing sound that is relatively easy to localize, with the psycho-acoustic result of perceiving that all sound is coming from those speakers.

While this tends to work fairly well in theory and in practice, there are things that can break this illusion. One example is the sub or objects adjacent to it can buzz/rattle, giving directional cues. I've also heard timing is a big factor for localization as well; if the subwoofer's contribution arrives to your ears early, you will tend to perceive that as the main source. This problem is a bit easier to deal with as reducing the distance of the subwoofer in your system setup, or otherwise introducing a small delay can improve the subjective result.

 

[killdozzer]

I can find my subs at 80 Hz. I tried 60Hz to mitigate that and while that helped I still left it at 80Hz so that by turning the subs off, I kill more sound that travels in condo heaven. A 120 Hz xo is something I use for some wall mounted speakers around the tv in Mantown. There's no way for me to blend that without co-locating the sub/s and speakers. You'd think I wouldn't care with the tinnitus and all but it bugs me to no end. I understand most people share your experience but there are people out there like me.

I've been reading a lot about these paesanos, it seems I'll have an exclusive opportunity to see whether it really works.

http://tinnitus-off.com/

Come on, give it a try!

 

[Alex2507]

This problem is a bit easier to deal with as reducing the distance of the subwoofer in your system setup, or otherwise introducing a small delay can improve the subjective result.

If you give up on women, call me.

 

[Alex2507]

Steve, I agree with the entirety of that post. First of all my head is like f^%&in' wide. Second, my living room has nearfield subs behind the couch. The #2 LP is right next to the left sub so I've always turned it down in the past to make that seat a little better. The timing trick is going to do more for that LP and I'm also going to distance the surround there as well. Much appreciated.

Both my systems have 2 subs and I can always tell which one is running if I turn the other off. It use to be even worse using a rec'r with a 12db/oct xo slope. THX mandates a 24 db/oct slope which is harder to locate.

BillyP's $2400 sealed PSA sub wasn't locatable at all. Same with Rick's Epik Empire. That was like being in a drum. It just came from everywhere. The subs I'm talking about aren't anywhere near that level ... if it's a boomy high q sub, would the transient response be at the same frequency as the fundamental?

 

[Steve81]

BillyP's $2400 sealed PSA sub wasn't locatable at all. Same with Rick's Epik Empire. That was like being in a drum. It just came from everywhere. The subs I'm talking about aren't anywhere near that level ... if it's a boomy high q sub, would the transient response be at the same frequency as the fundamental?

You will generally see some resonance associated with a peaky/boomy response. You can see an obvious example of this with Josh's measurements of an uncorrected Danley DTS10:

One other thing to keep in mind with crummier subs beyond their own buzzing/rattles is that high order THD could be a contributing factor as well.

 

[Alex2507]

You will generally see some resonance associated with a peaky/boomy response. You can see an obvious example of this with Josh's measurements of an uncorrected Danley DTS10:
View attachment 17817
One other thing to keep in mind with crummier subs beyond their own buzzing/rattles is that high order THD could be a contributing factor as well.

Well then I'm going in. I'll brace up the Infinity PS 10's in the living room. The DIY subs in Mantown resonate furniture as their tell. You're talking about the cabinet resonating, right? Not the cone itself hopefully.

We got Black Mass. I'm gonna do my distancing thing and sit in the #2 LP. We shall see.

 

[Steve81]

Not the cone itself hopefully.

The kind of resonance you'll see from a high Q alignment (i.e. underdamped) would be from the driver, but with respect to localization, I'm talking about unrelated mechanical noises (cabinet buzzing, ports rattling, and so on).

I'll brace up the Infinity PS 10's in the living room.

Just keep in mind that any changes in enclosure volume will affect tuning. Adding some glue and a couple strips of wood that add up to some small fraction of a liter won't really matter, but a couple window pane braces might.

 

[Alex2507]

The kind of resonance you'll see from a high Q alignment (i.e. underdamped) would be from the driver, but with respect to localization, I'm talking about unrelated mechanical noises (cabinet buzzing, ports rattling, and so on).


Just keep in mind that any changes in enclosure volume will affect tuning. Adding some glue and a couple strips of wood that add up to some small fraction of a liter won't really matter, but a couple window pane braces might.

I'm an all-thread and liquid nails kinda guy for bracing. While I'm in the all talk no action part of this project I just might install threaded inserts to fasten the driver down instead of wood screws.

So far so good with the sub in the #2 LP. It hasn't made itself known once so far. I better make sure it's working.

 

[Alex2507]

So far so good with the sub in the #2 LP. It hasn't made itself known once so far. I better make sure it's working.

Well, there's not much of a bass track there to begin with and to be clear, I set the subs to 2.5' instead of 6.5'. That's the right direction for a delay, right? At first I had it the wrong way and thought I hit gold due to limited LFE. That was embarrassing. It's late, I'm tired ... unless we watch the Amerikans. That's predictable bass ... ooh, maybe.

 

[Steve81]

Well, there's not much of a bass track there to begin with and to be clear, I set the subs to 2.5' instead of 6.5'. That's the right direction for a delay, right?

Yes, reducing the distance increases the delay, accounting for the time it takes for sound to propagate from a speaker located further away.

 

[herbu]

http://tinnitus-off.com/

Come on, give it a try!

It says:
"We recommend you listen to the therapy for 60 minutes or more daily. The best results are obtained with 90 minutes per day or more with quality headphones in a quiet surrounding.

You will feel first therapeutic effects after 3-6 months of listening."

60-90 minutes a day for 3-6 months? You can look for this one to be a required precursor to other treatment in our new socialized medicine.

 

[Alex2507]

It says:
"We recommend you listen to the therapy for 60 minutes or more daily. The best results are obtained with 90 minutes per day or more with quality headphones in a quiet surrounding.

You will feel first therapeutic effects after 3-6 months of listening."

60-90 minutes a day for 3-6 months? You can look for this one to be a required precursor to other treatment in our new socialized medicine.

Well you looked into it further than I did. I got a sixty year old Jewish doctor. He said if anything, my tinnitus was going to get worse as I got older. I was all done searching for further truths on the matter after paying for his professional advice. I abandoned that page as soon as it wanted me to register. Did they want money? I bet they wanted money.

 

[herbu]

Did they want money? I bet they wanted money.

I expect so. It's an app for your iPhone that somehow manipulates the frequency of your music. I didn't watch the video. Just scrolled down and saw their recommendation at the bottom. Even if free, I doubt many will dedicate the time. Maybe it's just their "easy out" for when somebody complains it didn't work.