Actuarial Outpost
 
Go Back   Actuarial Outpost > Actuarial Discussion Forum > Software & Technology
FlashChat Actuarial Discussion Preliminary Exams CAS/SOA Exams Cyberchat Around the World Suggestions

Actuarial Jobs by State

New York  New Jersey  Connecticut  Massachusetts 
California  Florida  Texas  Illinois  Colorado


Reply
 
Thread Tools Search this Thread Display Modes
  #681  
Old 10-24-2018, 11:50 AM
George Frankly's Avatar
George Frankly George Frankly is offline
Member
SOA AAA
 
Join Date: Aug 2011
Location: CO
Favorite beer: Sam Smith Oatmeal
Posts: 10,113
Default

Quote:
Originally Posted by Egghead View Post
Floyd then goes on to share lots of research that's been done since that 1971 one (that nobody read ). The ideal for movie listening seems to be Dolby's advice for 5.1 (with the surrounds a little behind the listener, but mostly to the side.) For music listening, listeners tend to prefer the surrounds to the side, and maybe somewhat forward. They have come up with an objective measure that correlates strongly with the sense of "spaciousness" known as Apparent Source Width (a subjective measure). The objective measure is known as Interaural Cross-Correlation Coefficient (IACC).



He then goes on to cite some pretty cool studies, where they found that a circle of evenly spaced speakers (24 of them!) could do a remarkably good job of recreating the experience of listening to music in a music hall (using 24 discrete microphones). Then the researchers tried different placement and numbers of speakers to see what the minimum needed was to get awfully close to reproducing it, and they landed on 4 or 5. The best with 5 speakers is the placement of:

* straight ahead
* front mains at 30 degrees off center
* rears at 120 degrees off center (so 30 degrees behind straight out to the sides)

But there were a number of arrangements that used only 4 speakers, among them a number with NONE of the speakers placed behind the listener, that were judged just as highly.
A question for you. When you put the surrounds at 80-90 degrees, you cite getting a wider soundstage, and that seems to make a lot of sense. In the past, I've often found an either/or situation when it comes to soundstage vs imaging. Do you still get a really cohesive center image when you're up-converting this way? Can you pinpoint where the bass player is standing?

Really curious. The imaging on my Gedlee is INSANE, but the sound stage is 'small.' Conversely, my Magnepans made my ~16' wide room sound as wide as a football field, but imaging was tough and the sweet spot in which you had to sit was roughly 3mm wide, lol.
Reply With Quote
  #682  
Old 10-24-2018, 11:54 AM
George Frankly's Avatar
George Frankly George Frankly is offline
Member
SOA AAA
 
Join Date: Aug 2011
Location: CO
Favorite beer: Sam Smith Oatmeal
Posts: 10,113
Default

Quote:
Originally Posted by Egghead View Post
Got my 2nd sub today. And at first ... I was kind of bummed. It sucked out a bunch of my bass. I thought, "How can this be? Two subs is supposed to be better, more even!"

Then I realized I had the phase switch on different settings for each sub. Much better results after flipping one!

Like George Frankly and others suggested, the main benefit of dual subs is more even bass in more chairs around the room.

An interesting side benefit: less rattling of the walls and windows. That's handy, because I've often found the rattles pretty distracting, especially from movies.
Woo! I bet there was a brief moment of panic before you flipped the phase switch. We've all done similar things, you spend time and money getting everything just right and then... ugh.

It's a bit worse in car audio, where the install takes dozens of hours, and it's harder to move things around once they are in there.

I got all the panels cut for my Volt's subwoofer box, will start gluing it up tonight and then sanding/finishing it. It's the strangest-looking box I've ever seen, I'm having to fight hard for every cubic inch of air space to cram a 10" sub underneath the trunk floor. I test-fitted the amp and DSP in their space and they have a bit of breathing room - important for keeping the amp cool. I got a 12v fan to circulate air. Everything will live under the trunk floor, so I'm keeping 100% of my trunk space, which is awesome, but it complicates the install.
Reply With Quote
  #683  
Old 10-24-2018, 07:05 PM
Egghead's Avatar
Egghead Egghead is offline
Member
SOA
 
Join Date: Aug 2006
Posts: 6,596
Default

Quote:
Originally Posted by George Frankly View Post
A question for you. When you put the surrounds at 80-90 degrees, you cite getting a wider soundstage, and that seems to make a lot of sense. In the past, I've often found an either/or situation when it comes to soundstage vs imaging. Do you still get a really cohesive center image when you're up-converting this way? Can you pinpoint where the bass player is standing?

Really curious. The imaging on my Gedlee is INSANE, but the sound stage is 'small.' Conversely, my Magnepans made my ~16' wide room sound as wide as a football field, but imaging was tough and the sweet spot in which you had to sit was roughly 3mm wide, lol.
In the multichannel stereo mode, I'm upmixing two-channel sound to 5.1. Sounds that coming from dead center come out of the center channel, but also come from the other speakers. So it's better "anchored" than a phantom center; i.e., you can move your head without it all falling apart. But it can also sound like vocals/instruments from the center are bigger/wider. Sometimes, I really like it. I find a lot of pop/rock to make the voice too "small" in 2.1, and so it sounds more natural in the 5.1 mode. In particular, duets drive me crazy in 2.1, as the soloists sound like they're sitting in each other's laps, while in 5.1 they sound like they're sitting not far apart from one another. Instruments that were hard-panned to the left speaker now sound like they're coming from a spot midway between my left and surround left speaker. It's really nice.

But songs that already have a good wide soundstage in 2.1 (using psychoacoustics to broaden the soundstage outside the speakers) can sound artificially big in 5.1. That's pretty rare, but when it happens, it sounds like a band of giants playing giant instruments.

So I go back and forth a bit, but mainly stay in 5.1.
Reply With Quote
  #684  
Old 10-24-2018, 07:11 PM
Egghead's Avatar
Egghead Egghead is offline
Member
SOA
 
Join Date: Aug 2006
Posts: 6,596
Default

Quote:
Originally Posted by George Frankly View Post
Woo! I bet there was a brief moment of panic before you flipped the phase switch. We've all done similar things, you spend time and money getting everything just right and then... ugh.

It's a bit worse in car audio, where the install takes dozens of hours, and it's harder to move things around once they are in there.
Yeah, it was more a moment of, "Well, that was a big freaking waste of money." Combined with, "Hmm, maybe this would work just fine if I stick the new sub in a position that my wife will never approve." It's funny how much of a difference that switch made.

Quote:
I got all the panels cut for my Volt's subwoofer box, will start gluing it up tonight and then sanding/finishing it. It's the strangest-looking box I've ever seen, I'm having to fight hard for every cubic inch of air space to cram a 10" sub underneath the trunk floor. I test-fitted the amp and DSP in their space and they have a bit of breathing room - important for keeping the amp cool. I got a 12v fan to circulate air. Everything will live under the trunk floor, so I'm keeping 100% of my trunk space, which is awesome, but it complicates the install.
Hope it works out for you!
Reply With Quote
  #685  
Old 11-01-2018, 01:15 AM
Egghead's Avatar
Egghead Egghead is offline
Member
SOA
 
Join Date: Aug 2006
Posts: 6,596
Default

Another advantage to having a dual sub: it's wiped out my ability to localize the bass. My original sub was at about the 10:00 position. Certain bass notes seemed to always be coming from that direction, which got distracting at times. Even with my second sub at about 4:00, my bass has the effect of being nice and centralized.
Reply With Quote
  #686  
Old 11-01-2018, 02:00 PM
George Frankly's Avatar
George Frankly George Frankly is offline
Member
SOA AAA
 
Join Date: Aug 2011
Location: CO
Favorite beer: Sam Smith Oatmeal
Posts: 10,113
Default

Quote:
Originally Posted by Egghead View Post
Another advantage to having a dual sub: it's wiped out my ability to localize the bass. My original sub was at about the 10:00 position. Certain bass notes seemed to always be coming from that direction, which got distracting at times. Even with my second sub at about 4:00, my bass has the effect of being nice and centralized.
Many people have posited over the years that bass can't be localized. And, in lab conditions, that may be true. If nothing else, subs tend to vibrate things close to them, and you can pick up on that. And subs produce harmonics, and those may be high enough in frequency to localize.

I'll say in my experience, subs do seem to sound localized, fwiw. And I agree with you, when I started doing multiple subs, the bass just seems uniform and immersive.
Reply With Quote
  #687  
Old 11-02-2018, 03:10 AM
Egghead's Avatar
Egghead Egghead is offline
Member
SOA
 
Join Date: Aug 2006
Posts: 6,596
Default

Major improvement tonight! The 5.2 all-towers configuration, with my surrounds at roughly +/- 80 degrees has allowed me to offset my screwed up hearing by playing around with the levels for each speaker.

I've complained at length in this thread about having a horribly skewed soundstage. Even in 2.1, I was able to get these awesome reflections to the left, which created a soundstage on that side that extended well beyond the speaker. But on the right side ... nothing. Sound on that side seemed to be coming directly from that speaker, and not at all beyond it.

I blamed it on the room acoustics. Spent a few hundred on acoustic room treatments. Made a little difference, but not a ton.

In 2.1, I used balance to shift volume toward the right, and that helped with placing the phantom center (which to my hearing always skewed left, understandably) but did virtually nothing to improve the soundstage problem. Again, sound extended well beyond the left speaker, but not past the right.

Even with the 5.2 setup, when I used the settings straight out of Audyssey, while it certainly improved things, the soundstage was still skewed pretty darn heavily to the left. I was finally getting the occasional sound outside of my right main, but still weak compared to the left side. And I've also complained that the 5.2 multichannel mode was making the soundstage artificially wide for some music. So I played around with my settings. The following have done an amazing job of restoring perceived balance, and giving me just the right soundstage for a broad range of music:

Center 0 (no change in level from Audyssey's pick)
Subs +6.0 dB each (Audyssey tends to set subs too low, and I'm a bit of a basshead)
Fronts 0
Surround L -1.5 (prevents soundstage being artificially wide on the left)
Surround R +2.5 (perfectly extends right soundstage - to my ears - to sound just like the left!)
Rear -6.0 (the Audyssey pick made it sound like I was in the middle of the band for multichannel stereo. This -6 setting gives me a nice sense of immersion, but definitely keeps the band in front of me. I'll have to bump it back up for movie listening.)

Last edited by Egghead; 11-02-2018 at 03:22 AM..
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 09:32 PM.


Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
*PLEASE NOTE: Posts are not checked for accuracy, and do not
represent the views of the Actuarial Outpost or its sponsors.
Page generated in 0.19637 seconds with 10 queries