Head-Fi.org › Forums › Equipment Forums › Sound Science › Bass management issue
New Posts  All Forums:Forum Nav:

Bass management issue - Page 2

post #16 of 22
Thread Starter 
Quote:
Yes: you have a sub, and then get to pick large (sub gets LFE only, no crossover active), or small (sub gets all bass, crossover frequency affects both mains and sub)

 

So if you use this configuration and you go into the Subwoofer advanced menu and choose 40 Hz it won't do anything if all speakers have been set to Large? What I don't understand is that if 40 Hz is even an option in the Subwoofer menu, does that mean the LFE low-pass will also be 40 Hz? Because if that's true it would truncate bass from 40 - 120 Hz as the LFE has information up to 120 Hz!


Edited by Mezzo - 4/9/13 at 12:20pm
post #17 of 22
Quote:
Originally Posted by Mezzo View Post

 

So if you use this configuration and you go into the Subwoofer advanced menu and choose 40 Hz it won't do anything if all speakers have been set to Large?

Speakers:Large, Sub: yes  -- you get only LFE in the sub, and that's pre-filtered for 80Hz LPF during mixing, so no LPF involved.  Under those setting conditions, you probably won't even see the option for a crossover setting.

 

Speakers: Large, Sub: Max - you get LFE plus all bass from all other channels below the x-over frequency.  All other channels get full bandwidth.  Crossover setting is really just the LPF in the sub feed, and has no effect on the full bandwidth channels.

post #18 of 22
Thread Starter 
Quote:
Speakers: Large, Sub: Max - you get LFE plus all bass from all other channels below the x-over frequency.  All other channels get full bandwidth.  Crossover setting is really just the LPF in the sub feed, and has no effect on the full bandwidth channels.

If all other channels are Large and Max then the 40 Hz low pass will just duplicate bass 40 Hz and below to the subwoofer, even though there are no crossovers.

 

I'm about to give up with this. He has set 40 Hz in the subwoofer menu but I'll just accept that if all speakers are Large and sub is "Yes" then there is no low-pass setting because there is no low-pass filter to set. No manufacturer is going to offer a function to truncate bass from 40-120 Hz.

post #19 of 22
Quote:
Originally Posted by Mezzo View Post

If all other channels are Large and Max then the 40 Hz low pass will just duplicate bass 40 Hz and below to the subwoofer, even though there are no crossovers.

The 40Hz LPF is 1/2 of a crossover...the part that deals with the sub.  This is not an invalid setting.

 

Quote:

Originally Posted by Mezzo View Post

I'm about to give up with this. He has set 40 Hz in the subwoofer menu but I'll just accept that if all speakers are Large and sub is "Yes" then there is no low-pass setting because there is no low-pass filter to set. No manufacturer is going to offer a function to truncate bass from 40-120 Hz.

If he is indeed using "Yes" instead of "Max", then you are correct, there's no 40Hz LPF to set.  The sub will only get LFE.  This is also not entirely invalid, but it depends on the mains to have excellent extended bass down to 20Hz.  Not impossible, just unlikely.  

 

But in no case would there be a loss of bass between 40-120Hz.  This is because, if set to Large, the mains will get full bandwidth all the way down past 40Hz, to below 20Hz.  If set to "Small", then whatever frequency is chosen should result in a seamless splice between the mains (rolled off below the set freq.) and the sub (beginning its response from the set point and down).  Even if set to "Large" and "Max", and 40Hz, there will be no gap in response, though without calibration, the "splice" between the mains and sub may not exactly be smooth. 

 

I understand you are frustrated.  But perhaps, rather than to just say he's wrong, go give it a listen.  It just might work fine in that room.  Remember that below about 200Hz bass is all about the room, and having more bass speakers working is actually an advantage. 

post #20 of 22
Quote:
Originally Posted by Mezzo View Post

 

So if you use this configuration and you go into the Subwoofer advanced menu and choose 40 Hz it won't do anything if all speakers have been set to Large? What I don't understand is that if 40 Hz is even an option in the Subwoofer menu, does that mean the LFE low-pass will also be 40 Hz? Because if that's true it would truncate bass from 40 - 120 Hz as the LFE has information up to 120 Hz!

I don't think you can do that but if so, the logical assumption is the missing bass would be redirected to the large fronts. The same as if there was no woofer at all. It's somewhere and never duplicated. The DSP will be programmed for it. Only way to completely lose some signal is to tell the unit that there's a woofer when there isn't.(you won't be allowed to select small fronts without a woofer).

 

We're getting into nonsensical theoreticals that are generally not allowed to you. I think that if you research further you'll find that I'm correct. These units are designed to not let you screw up too badly though it's certainly no guarantee. LOL


Edited by goodvibes - 4/9/13 at 6:03pm
post #21 of 22
Quote:
Only way to completely lose some signal is to tell the unit that there's a woofer when there isn't.(you won't be allowed to select small fronts without a woofer).


You would imagine this would be the case. I think it's just a poorly written manual I think.


Edited by Yahzi - 4/10/13 at 1:02am
post #22 of 22
Quote:
Originally Posted by jaddie View Post

If he is indeed using "Yes" instead of "Max", then you are correct, there's no 40Hz LPF to set.  The sub will only get LFE.  This is also not entirely invalid, but it depends on the mains to have excellent extended bass down to 20Hz.  Not impossible, just unlikely.  

 

But in no case would there be a loss of bass between 40-120Hz.  This is because, if set to Large, the mains will get full bandwidth all the way down past 40Hz, to below 20Hz.  If set to "Small", then whatever frequency is chosen should result in a seamless splice between the mains (rolled off below the set freq.) and the sub (beginning its response from the set point and down).  Even if set to "Large" and "Max", and 40Hz, there will be no gap in response, though without calibration, the "splice" between the mains and sub may not exactly be smooth. 

 

I understand you are frustrated.  But perhaps, rather than to just say he's wrong, go give it a listen.  It just might work fine in that room.  Remember that below about 200Hz bass is all about the room, and having more bass speakers working is actually an advantage. 

 

Also listening preferences. Back when I had a full set-up in my car's trunk I had the front midwoofers cut at 80hz, 12db/octave, while the sub in the trunk was set to 50hz, 24db/octave. Everyone who went, "cut it higher!" or "that's too steep!" or "more bass gain!" ended up with the bass drums moving away from the dashboard, and double pedals - even if coming mostly from the front - were accompanied by a molasses tsunami of bass. At my settings, the sub was invisible; disconnect the sub, and the its absence will be immediately noted. My other amp broke though, and over the years, I got used to not having a sub in favor of a larger cooler (hence more beer, more steaks, more pork ribs and thick-cut bone-in belly).


Edited by ProtegeManiac - 4/10/13 at 8:26pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › Bass management issue