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Double bass and bass management - Page 5

post #121 of 238
Quote:
Originally Posted by OllieS View Post

Guys, Ed and Craig, thank you so much for contributing. You have helped a great deal.

Just wanted to ask you. I have a friend who is running all speakers as large. He has a Jamo 12" sub that he reckons goes down to about 25 Hz. His main speakers go down to 40 Hz. In his processor he has it set at 40hz lowpass, its -24db/oct, subwoofer itself is dialed to its min which is 70hz. I heard from Scarpelli that if you don't use a crossover that the mains will superimpose it;s frequency response on to the sub. I'm not sure how much is superimposed on the setup I proposed above.

Correct me if I'm wrong, but don't you want some of the bass to be superimposed for a smoother transition between speaker and sub? I thought that was the goal, for a seamless transition unless I completely missed the boat. I wish I could ask Paul directly, but I think you chaps are more than qualified to answer in his absence! smile.gif

Running all the speakers on Large (which means they are sent a full-range signal) is generally not a good idea. Under very isolated circumstances I can make a case for it if the mains are towers which truly have usable extension/output to well below 40 Hz (and that's not very many towers). Even then it would simply be an alternative to try, and will not necessarily perform better than high passing the mains.

You have not provided enough information about the bass management options in your friend's pre/pro, nor do we know enough about the rest of his speakers. Generally only Audyssey equipped AVRs (Denon, Onkyo, Marantz, Integra) have sophisticated and flexible bass management options like we've been discussing above which would allow him to set the fronts to Large, the sub to LFE+Main, and then the mains 'crossover' (which in reality becomes a low pass for the subwoofer) to 40 Hz.

At any rate, if the mains really do start to roll-off at 40 Hz, then the above settings would indeed provide a reasonably smooth transition to the subwoofer, since the acoustic roll-off from the mains and the electrical slope of the subwoofer low pass would both be 4th order. As Craig indicated above - there are a lot of qualifiers in any set-up, and what actually happens acoustically in the room rarely matches theory perfectly.

Your friend should try a few different bass management options to see which sound/performs best in his set-up/room. But I can almost guarantee that setting all of his speakers to Small (with the possible exception of the mains) is the way ahead. For the mains he can try Small/40 Hz, Large/LFE, or Large/LFE+Main/40 Hz as the three basic options. The low pass filter at the subwoofer itself should always be bypassed to avoid double-filtering.
post #122 of 238
Thread Starter 
Quote:
Originally Posted by Ed Mullen 
You have not provided enough information about the bass management options in your friend's pre/pro, nor do we know enough about the rest of his speakers.

What information would you like to know? He isn't using double bass or LFE+Main. It appears he has set all speakers to Large and is allowing his main speakers to roll-off naturally (he believes they have a -3db at 40 Hz ). He has chosen a 40 Hz low pass in the processor at 24/db octave. But then ... he says he has dialed his subwoofer to 70 Hz. Which I imagine is his low-pass filter on his sub.

He likes his system set up this way. Now I don't know what kind of overlap or cancellation would take place with this set up, but if I can tell him what is wrong and why it's wrong it would be a great help to him.

PS I set my speakers to small, 60 Hz crossover and I think I like the system that way.
post #123 of 238
Thread Starter 
Sorry Ed, in your experience do you feel "Small" settings almost always give smoother, more uniform response at the seats compared to all speakers set to Large? I wish I could see some measurement graphs so I could see it, but I don't have any measurement tools at the moment. frown.gif
post #124 of 238
Quote:
Originally Posted by OllieS View Post

Sorry Ed, in your experience do you feel "Small" settings almost always give smoother, more uniform response at the seats compared to all speakers set to Large? I wish I could see some measurement graphs so I could see it, but I don't have any measurement tools at the moment. frown.gif

Is there enough in the personal budget for a sound level meter? If so, with a freeware download of REW, you're well on your way to empirically measuring your friend's room.
post #125 of 238
Quote:
Originally Posted by OllieS View Post

He isn't using double bass or LFE+Main. It appears he has set all speakers to Large and is allowing his main speakers to roll-off naturally (he believes they have a -3db at 40 Hz ). He has chosen a 40 Hz low pass in the processor at 24/db octave. But then ... he says he has dialed his subwoofer to 70 Hz. Which I imagine is his low-pass filter on his sub.
If all the speakers are set to LARGE, how is there a 40Hz low-pass being applied at the processor?
post #126 of 238
Thread Starter 
Quote:
Originally Posted by sivadselim 
If all the speakers are set to LARGE, how is there a 40Hz low-pass being applied at the processor?

I don't know. He just said he has the low pass set to 24 dB/octave at 40 Hz in his processor. Speakers set to Large (all round) and subwoofer set to 70 Hz at the back. Perhaps he was confused but that's exactly what he told me.
post #127 of 238
Quote:
Originally Posted by OllieS 
I don't know. He just said he has the low pass set to 24 dB/octave at 40 Hz in his processor. Speakers set to Large (all round) and subwoofer set to 70 Hz at the back. Perhaps he was confused but that's exactly what he told me.

This doesn't make sense. If you were referring to the LFE low lass filter then I doubt there would be a 40 Hz option for you to choose as you would be truncating the LFE track above 40 Hz. It is a little unclear how your friend has set up his system based off the information you have presented.
post #128 of 238
Quote:
Originally Posted by J e f f View Post

On My Demon 2112 you can cross the mains when there set to large if the lfe+main setting is on

After reading this, I went home and checked my Denon 2113ci - sure enough, this is the case with mine as well.
post #129 of 238
The below was brought to my attention yesterday.

Just saying, Chris at Audyssey, don't like this.

See follow up comments by Chris:

Quote:
Audyssey doesn't set speakers to Large or Small and most certainly doesn't set the sub to LFE+Main. These are decisions that the AVR makes. We recommend that if there is a subwoofer in the system, then all speakers should be set to Small and the sub mode should be LFE (not LFE+Main).

The LPF setting for the LFE channel should always be 120 Hz. This is not a crossover, but a filter that applies only to the separate LFE track found in 5.1 content.

In my opinion, that's as clear of a position as Chris could have taken. That's why one needs room measuring capabilities, so they can obtain immediate feedback regarding how any changes one might make to their settings, have on the sound system's output.
post #130 of 238
Quote:
Originally Posted by BeeMan458 View Post

The below was brought to my attention yesterday.

Just saying, Chris at Audyssey, don't like this.

See follow up comments by Chris:
In my opinion, that's as clear of a position as Chris could have taken. That's why one needs room measuring capabilities, so they can obtain immediate feedback regarding how any changes one might make to their settings, have on the sound system's output.

Correct. It's important to make this distinction - we are talking about Audyssey equipped AVRs (Denon, Onkyo, Marantz, Integra) which all have similar bass management menu options. The core function of Audyssey is to level match, set distance, and equalize - it does not make bass management determinations. That is done by the AVR manufacturer and has nothing to do with Audyssey per se. It just so happens that Audyssey equipped AVRs typically have these more advanced bass management menu options.
post #131 of 238
Thread Starter 
Please correct me if I'm wrong, but if you select Large for all speakers then the subwoofer must only handle the LFE channel? The only low pass that is done is at the subwoofer preout,which is usually 80-120 Hz?
post #132 of 238
Quote:
Originally Posted by OllieS View Post

Please correct me if I'm wrong, but if you select Large for all speakers then the subwoofer must only handle the LFE channel? The only low pass that is done is at the subwoofer preout,which is usually 80-120 Hz?
Correct. Unless a double bass setting is used. And only if ALL speakers are set to LARGE. If any other channels are set to SMALL (crossed over) then the rerouted bass below the crossover setting for those channels is, of course, sent to the subwoofer, too.

All of your questions have been answered in spades in this thread and your other one (as well as discussed ad nauseum in dozens, if not hundreds, of other threads here in these, and other, forums), so why do you keep asking the same elementary questions over and over again?
post #133 of 238
Thread Starter 
Because certain things I need to have repeated for them to stick in my head. Otherwise I won't truly understand what is going on. I NOW understand how the low-pass works.
post #134 of 238
Quote:
Originally Posted by OllieS View Post

Because certain things I need to have repeated for them to stick in my head. Otherwise I won't truly understand what is going on. I NOW understand how the low-pass works.

Ask away as many times as you need to.

There's nothing wrong with asking and by asking, it don't mean the grumpy, need to reply.
post #135 of 238
Thread Starter 
Quote:
Originally Posted by BeeMan458 
There's nothing wrong with asking and by asking, it don't mean the grumpy, need to reply.

I do feel like I'm under the gun and if I don't understand something then I'm called a "troll" or an "ingrate". rolleyes.gif I may not understand certain things so giving me quick answers is not really what I'm after. I need to understand the mechanism behind it, otherwise I'll never really "get" it. I'm not as clued up as the rest of you are although I wish I was, but hopefully I'll get there.

Thanks for chiming in.
post #136 of 238
Quote:
Originally Posted by OllieS View Post

Thanks for chiming in.

My pleasure. Lots of grumpy people here and they don't realize how terrible they are at articulating a response.

A suggestion, Google up a lot of your questions as I found this enhances what other here have to share. I've spend a great deal of time using Google to further my understanding and by drips and drabs, it slowly, over the many months, congeals into a large, gelatinous mass of continued confusion. tongue.gif

Some understand this point, others don't want to. biggrin.gif

-
Edited by BeeMan458 - 4/8/13 at 1:38pm
post #137 of 238
Quote:
Originally Posted by OllieS View Post

I NOW understand how the low-pass works.
Oh yeah? rolleyes.gif
post #138 of 238
Quote:
Originally Posted by OllieS View Post

I may not understand certain things so giving me quick answers is not really what I'm after. I need to understand the mechanism behind it, otherwise I'll never really "get" it. I'm not as clued up as the rest of you are although I wish I was, but hopefully I'll get there.
Several people here, myself included, have given you very well-thought out and thorough responses in both this thread and your other one. Although understandably confusing for a novice, it's not rocket science. At all. What is it you don't "get"?
post #139 of 238
I have a question for the elite bass management warriors. If, assuming you have all speakers set to Large and you are not able to select a low-pass for the LFE track, then what is the subwoofer preout low-pass filtered to? I would imagine it is brick-wall filtered to 120 Hz in lieu of any user adjustable LPF of LFE.
post #140 of 238
Quote:
Originally Posted by goneten View Post

I have a question for the elite bass management warriors. If, assuming you have all speakers set to Large and you are not able to select a low-pass for the LFE track, then what is the subwoofer preout low-pass filtered to? I would imagine it is brick-wall filtered to 120 Hz in lieu of any user adjustable LPF of LFE.
If your receiver doesn't have an LPF of LFE, it probably doesn't have the ability to decode Dolby TrueHD or DTS MA either. The legacy codecs, (DD and DTS), were brick wall filtered at 120 Hz on the recording/mixing end and therefore they didn't need a LPF of LFE on the playback end. In the lossless codecs, the LFE channel is specified as a full range channel, so an LPF of the LFE channel was needed on the playback end. An LPF of LFE is a requirement for any receiver or pre/pro that has the ability to decode the lossless codecs.

Craig
post #141 of 238
Quote:
If your receiver doesn't have an LPF of LFE, it probably doesn't have the ability to decode Dolby TrueHD or DTS MA either.
There's at least one exception to every rule smile.gif : My Marantz SR6003 doesn't have an LPF of LFE, but it decodes Dolby TrueHD and DTS-HD MA.
post #142 of 238
Quote:
Originally Posted by craig john 
If your receiver doesn't have an LPF of LFE, it probably doesn't have the ability to decode Dolby TrueHD or DTS MA either.

Looking at Ollie's fascination with his Rotel processor I noticed it had no option to select the LFE low pass. It is an old processor that does not decode DTS HD or Dolby True HD. So I assume if there was no user adjustable low-pass for the LFE that it would default to 120 Hz.
post #143 of 238
Quote:
Originally Posted by OllieS View Post

Because certain things I need to have repeated for them to stick in my head. Otherwise I won't truly understand what is going on. I NOW understand how the low-pass works.

That is a good reply. If you can explain it to someone else, it means you understand it.

I have been closely lurking in this thread, trying to follow the logic on double bass as others have explained it. I'm going to print out this entire thread and keep it by my Onk 717, so I can try some of these suggestions.
post #144 of 238
Quote:
Originally Posted by sivadselim View Post


All of your questions have been answered in spades in this thread and your other one (as well as discussed ad nauseum in dozens, if not hundreds, of other threads here in these, and other, forums), so why do you keep asking the same elementary questions over and over again?

I just saw your Avatar; you have 15 thousand posts on here; you are fully addicted to this stuff.

It may well help you to understand, that some of us are just starting our addictions. cool.gif
post #145 of 238
Quote:
Originally Posted by craig john View Post

If your receiver doesn't have an LPF of LFE, it probably doesn't have the ability to decode Dolby TrueHD or DTS MA either. The legacy codecs, (DD and DTS), were brick wall filtered at 120 Hz on the recording/mixing end and therefore they didn't need a LPF of LFE on the playback end. In the lossless codecs, the LFE channel is specified as a full range channel, so an LPF of the LFE channel was needed on the playback end. An LPF of LFE is a requirement for any receiver or pre/pro that has the ability to decode the lossless codecs.

Craig

I tend to agree that the LFE channel is likely always low passed at 120 Hz if you can't see and adjust the low pass. As discussed elsewhere, most clearly by Ed Mullen, if you have a receiver that "does" double bass and no ability to set the low pass for the "doubled" bass from front, center and right, there's a low pass of unkown frequency and slope luriking in there somewhere.
post #146 of 238
Thread Starter 
Quote:
Originally Posted by sivadselim 
Several people here, myself included, have given you very well-thought out and thorough responses in both this thread and your other one. Although understandably confusing for a novice, it's not rocket science. At all. What is it you don't "get"?

I told my friend that he should disable the low pass in the subwoofer instead of having both working together. That is something I have learned recently. You can't have filters working together. His reply to me was that most speakers have passive crossovers within... so any crossover you setup on a receiver or a processor is in effect still/also cascading and that in some cases you will effectively be creating a bandpass xover of x+y order.

I'm not clued up on this kind of stuff, so I don't know what my friend is telling me is true.
post #147 of 238
Quote:
Originally Posted by OllieS View Post

I told my friend that he should disable the low pass in the subwoofer instead of having both working together. That is something I have learned recently. You can't have filters working together.
Yes, you can. All that changes is the low pass slope when you cascade both, and that can be quite beneficial in reducing above bandwidth content from the sub. The filters in AVRs are hardly brick wall.
post #148 of 238
The crossover in the speaker is between the drivers and tweeter and far above the bass frequencies, usually in the 2khz range. So completely different things and they do not impact each other.
Quote:
Originally Posted by OllieS View Post

I told my friend that he should disable the low pass in the subwoofer instead of having both working together. That is something I have learned recently. You can't have filters working together. His reply to me was that most speakers have passive crossovers within... so any crossover you setup on a receiver or a processor is in effect still/also cascading and that in some cases you will effectively be creating a bandpass xover of x+y order.

I'm not clued up on this kind of stuff, so I don't know what my friend is telling me is true.
post #149 of 238
Quote:
Originally Posted by Bill Fitzmaurice View Post

Yes, you can. All that changes is the low pass slope when you cascade both, and that can be quite beneficial in reducing above bandwidth content from the sub. The filters in AVRs are hardly brick wall.
I'll stop short of calling that ill-advised but I won't stop short of calling entering that idea into this particular thread ill-advised. wink.gif
post #150 of 238
Thread Starter 
Quote:
Originally Posted by prinetimeguy 
The crossover in the speaker is between the drivers and tweeter and far above the bass frequencies, usually in the 2khz range. So completely different things and they do not impact each other

So there is no cascading going on? Not sure why he would think this.
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