!!which hz do i assign the sub!!

tavogee

Hi, which Hz should I assign to the subwoofer. Also, what gives more deep bass 80Hz or 120Hz? Thanks:redface:

Matt34

What speakers are you running?

What receiver? Does it have individual crossover points for each channel?

What subwoofer do you have?

Knucklehead

i would set it 80hz on your AVR, turn your sub all the way to 160hz and adjust the volume to your desired level.

David

kuntasensei

tavogee wrote: »

Hi, which Hz should I assign to the subwoofer. Also, what gives more deep bass 80Hz or 120Hz? Thanks:redface:

If you're talking about the LPF of LFE on the receiver, 120Hz is the only correct setting. It would probably help to know what receiver we're talking about here.

newrival

kuntasensei wrote: »

If you're talking about the LPF of LFE on the receiver, 120Hz is the only correct setting. It would probably help to know what receiver we're talking about here.

Why 120Hz? The correct THX setting is 80Hz

tavogee

I have an Onkyo TX-NR808 Receiver (using as a pre-amp) to the Emotiva XPA-5. My speakers are Polk, fronts are RTi A9's, my center is Csi A6, my surrounds are F/Xi A6 and my subwoofer is the new DSW PRO 660wi (hard wired). I have the subwoofer hooked up to the Onkyo sub-out via an RCA cable to the LFE/R input on the subwoofer. When in this configuration the "LOW PASS FILTER" knob on the subwoofer becomes disabled, any settings must be done via the setup menu of the Onkyo Receiver. Why is 120Hz the only correct setting? The onkyo receiver manual setup (not audessey) for the sub allows me to assign either 80Hz, 90Hz, 100Hz or 120Hz (this is the Low Pass Filter for the LFE Channel), this is the setting that overides and disables the "LOW PASS FILTER" knob I was talking about earlier. But still, can anyone tell me which setting gives more of a deep bass 80Hz or 120Hz? Also, why am I only able to set the subwoofer to 80Hz when I have read that it can handle 25Hz, am I missing something here. Thanks for the help, talk to you soon.

kuntasensei

newrival wrote: »

Why 120Hz? The correct THX setting is 80Hz

That's ONLY for subwoofers designed per THX specs, which are only designed to handle up to 80Hz, whereas the vast majority of subwoofers can handle above that. THX certified receivers typically default to 80Hz LPF of LFE as part of their compliance with THX specs. However, the LFE channel contains information up to 120Hz by design and mixers roll it off appropriately during the mix so that LFE doesn't become directional, so there's no need to introduce an additional filter into that channel. 120Hz is the correct setting (and the ONLY correct setting) because that's the point where the LFE channel is brickwall-filtered anyway. The reason you don't want to roll that channel off at 80Hz is because even though mixers primarily use the LFE channel for sub-80Hz effects, there are harmonics above 80Hz that lend those effects their perceived tone.

This filter doesn't affect redirected bass from the other channels that you've set crossovers for - just audio placed in the LFE channel - so it will not make your subwoofer easier to localize.

tavogee

When I ran audessey (microphone), it had assigned the L/R Fronts and Center to 40Hz, and assigned the L/R surrounds to 50Hz. On top of that it assigned the subwoofer to 120Hz. Maybe newrival is right in a sense. Audessey did assign 120Hz to my sub, but I feel that to be incorrect. ANYONE!

Knucklehead

Knucklehead wrote: »

i would set it 80hz on your AVR, turn your sub all the way to 160hz and adjust the volume to your desired level.

David

^^^^^^

tavogee

How do I know if the DSW PRO 660wi is THX Certified. Could the receiver be THX, or that doesn't apply to receivers. What about the rest of my polk speakers. Do I need to call Polk and ask them if these items are THX? Thanks TAVO

Knucklehead

THX certified is mostly bogus crap that makes George Lucas money.

tavogee

Even if I turned the sub LPF knob all the way up to 160Hz, according to the Onkyo owners manual, that knob is disabled. So would that even be an issue here?

kuntasensei

tavogee wrote: »

I have an Onkyo TX-NR808 Receiver (using as a pre-amp) to the Emotiva XPA-5. My speakers are Polk, fronts are RTi A9's, my center is Csi A6, my surrounds are F/Xi A6 and my subwoofer is the new DSW PRO 660wi (hard wired). I have the subwoofer hooked up to the Onkyo sub-out via an RCA cable to the LFE/R input on the subwoofer. When in this configuration the "LOW PASS FILTER" knob on the subwoofer becomes disabled, any settings must be done via the setup menu of the Onkyo Receiver. Why is 120Hz the only correct setting? The onkyo receiver manual setup (not audessey) for the sub allows me to assign either 80Hz, 90Hz, 100Hz or 120Hz (this is the Low Pass Filter for the LFE Channel), this is the setting that overides and disables the "LOW PASS FILTER" knob I was talking about earlier. But still, can anyone tell me which setting gives more of a deep bass 80Hz or 120Hz? Also, why am I only able to set the subwoofer to 80Hz when I have read that it can handle 25Hz, am I missing something here. Thanks for the help, talk to you soon.

First, a quick and dirty basic lesson in filters:
1) A high pass filter filters out anything BELOW that point. So if a HPF is set at 80Hz, it gradually rolls off sound below that frequency.
2) A low pass filter filters out anything ABOVE that point. So if a LPF is set at 80Hz, it gradually rolls off sound above that frequency.
3) A crossover is a combination of a high pass filter and a low pass filter that typically serves as a transition from one speaker to another. In this case, a crossover of 80Hz means that at approximately 80Hz, the audio transitioning from one driver to the other is at roughly the same level in both drivers.

Therefore, the "LPF of LFE" control sets the point that the LFE channel (and only the LFE channel) is filtered. For example, setting the LPF of LFE to 80Hz gradually rolls off any audio above 80Hz. Here's the thing though: The LFE channel is brickwall filtered during encoding at 120Hz. Therefore, the only way to properly reproduce the full content of that channel is to pass audio all the way up to 120Hz to your subwoofer. That is why the only correct LPF of LFE setting for non-THX-designed subwoofers is 120Hz.

As I said before, this setting does NOT affect audio redirected to the sub from the other channels. You can set LPF of LFE to 80Hz and your other crossovers to 120Hz and your AVR will still send the 80-120Hz audio from the other channels to the subwoofer, because the LPF of LFE control doesn't filter the entire output channel - just the digital LFE channel.

It's important to note that Audyssey does NOT adjust the LPF of LFE control because 1) there's no reason to test for it and 2) the LPF of LFE control only exists to maintain compatibility with THX-spec'd subwoofers. Therefore, even if you run Audyssey's room equalization, you should manually adjust this control to 120Hz. Additionally, Audyssey sends the AVR's software data on where your speaker's lower -3dB point is, which your AVR's software uses to decide where to set the crossovers. If you have capable speakers all the way around (and you do), odds are good that running Audyssey will set all your channels to a 40Hz crossover. It's okay to turn the crossovers UP from the detected point, but if you're using Audyssey, never turn them BELOW that point because Audyssey does not do any equalization below that point.

Bottom line: You're correct in using the unfiltered input on the sub, which gets the filtering circuitry in the sub out of the way and lets all the filtering happen on a digital level in the AVR, minimizing phase issues that can throw off proper speaker distance settings and preventing the cascading of two filters that would create a gap in frequency response. Any filtering that needs to be done will then be handled by the crossover points set in the AVR, and setting LPF of LFE to 120Hz will let the full LFE channel pass to your subwoofer unaltered.

Knucklehead

tavogee wrote: »

Even if I turned the sub LPF knob all the way up to 160Hz, according to the Onkyo owners manual, that knob is disabled. So would that even be an issue here?

Yes, mostly to be on the safe side when you start playing around with the AVR crossover.

kuntasensei

tavogee wrote: »

How do I know if the DSW PRO 660wi is THX Certified. Could the receiver be THX, or that doesn't apply to receivers. What about the rest of my polk speakers. Do I need to call Polk and ask them if these items are THX? Thanks TAVO

It isn't. Very few subwoofers now are designed to THX specs, and the LFE channel does not need to be filtered for non-THX subs. As far as the crossover points for your other speakers, you have enough amplification to run them at the crossovers Audyssey detected, but I recommend bumping them all up to at least 60Hz. This is something you can adjust critically during listening material to see whether the speakers or the sub handles that bass better.

kuntasensei

BTW: Don't take my word for it. Professor Chris Kyriakakis of Audyssey has addressed this question several times:
http://ask.audyssey.com/forums/64701/entries/321931.html
http://ask.audyssey.com/entries/191907-bass-management

tavogee

Thanks Kuntasensei and Knucklehead, I will have to read this a few times for it to sink in. This was very valuable information to me. makes sense (kinda). Thanks TAVO

tavogee

Back again, I read one of the audyssey articles where the gentleman states to turn up the "LOW PASS FILTER" knob on the subwoofer all the way up because the internal croosover interferes with the bass management (or something similiar). My point is, I thought that the knob was inactive when using the sub-out to LFE configuration via RCA cable (according to the Onkyo owners manual). So, if the knob is inactive, why would I need to turn it all the way up, according to the audyssey gentleman?

newrival

i'm not sure. I don't think there is an "unfiltered input" on my Sunfire plate amp. I'll check again, but I think the xover point is always adjustable for all inputs, so this may be why he says it.

kuntasensei

tavogee wrote: »

Back again, I read one of the audyssey articles where the gentleman states to turn up the "LOW PASS FILTER" knob on the subwoofer all the way up because the internal croosover interferes with the bass management (or something similiar). My point is, I thought that the knob was inactive when using the sub-out to LFE configuration via RCA cable (according to the Onkyo owners manual). So, if the knob is inactive, why would I need to turn it all the way up, according to the audyssey gentleman?

It might be inactive. It might not. If the sub has both an LFE in and a line in, odds are that the LFE in bypasses the filter. Regardless, turn it to its maximum BEFORE running Audyssey just to make sure it is out of the way.

tavogee

Yesterday, I called Polk and asked them what they would recommend the crossovers set at. Polk customer rep told me to set everything at 80HZ. They said not to worry about the subwoofer LOW PASS FILTER knob on the back. They told me that it was disable automatically once I went with the sub-out to LFE in on the subwoofer. I tried those settings and did not care for them, my setup sounded better 60Hz in the fronts/center, 80Hz on the surrounds and sub. I am still experimenting.

comfortablycurt

As kuntasensei stated above, 120hz is the correct setting. I could reiterate the reasons why, but he basically said it all in his posts.

Regarding the issue with turning the subs internal XO up all the way...

Yes, technically it should be out of the way automatically when using the LFE input. However, it's quite simple to turn the knob up all the way, just to ensure, without question...that it's completely out of the way. It shouldn't make any difference, but there's always the possibility that the circuitry doesn't get it 100% out of the way...so it's simple enough to just turn it up all the way for some cheap insurance.

kuntasensei

tavogee wrote: »

Yesterday, I called Polk and asked them what they would recommend the crossovers set at. Polk customer rep told me to set everything at 80HZ. They said not to worry about the subwoofer LOW PASS FILTER knob on the back. They told me that it was disable automatically once I went with the sub-out to LFE in on the subwoofer. I tried those settings and did not care for them, my setup sounded better 60Hz in the fronts/center, 80Hz on the surrounds and sub. I am still experimenting.

Yeah, since you're running external amplification, you're fine going 60Hz for the front/center. The 80Hz recommendation is typically for people running just off the AVR, since that passes off more of the power needs to the subwoofer and frees up headroom on the AVR.

And you say "80Hz on the surrounds and sub". As I stated before, there is no crossover for the subwoofer in your AVR. The reason I say this is:
1) LPF of LFE is not a crossover - it's just a low pass filter.
2) It doesn't affect the entire subwoofer output - just the LFE channel.

I know I'm beating a dead horse here... but LPF of LFE = 120Hz. No debate, no question, that is the only correct setting for that control, no matter what anyone tells you. Setting it to anything else throws sound away that the mixer intended you to hear, because that sound isn't redirected to any other speaker - it is just filtered out completely.

jbooker82

I want to start off by saying I am new to ht systems and just starting to build mine with the stuff in my signature.

I understand that the LFE channel contains sound up to 120hz. Why wouldnt you want the RTI A9's to handle the sounds between 80hz to 120hz and let the sub handle sounds 80hz and lower? (setting the xo for the life output in the avr to 80hz).

Are there sounds in movies that are specifically assigned to the LFE channel and they will not be reproduced in the other channels of a AVR?

So if you have the LFE set at 80hz in the AVR and say the RTI A9's set to 60hz in the AVR. According to the settings the sub and RTI A9's will over lap, but you still end up with hole in bass sounds from 120hz to 80hz because spacific sounds have been assigned (by the sound track of a movie) to the LFE channle above 80hz.

kuntasensei

jbooker82 wrote: »

I understand that the LFE channel contains sound up to 120hz. Why wouldnt you want the RTI A9's to handle the sounds between 80hz to 120hz and let the sub handle sounds 80hz and lower? (setting the xo for the life output in the avr to 80hz).

Are there sounds in movies that are specifically assigned to the LFE channel and they will not be reproduced in the other channels of a AVR?

So if you have the LFE set at 80hz in the AVR and say the RTI A9's set to 60hz in the AVR. According to the settings the sub and RTI A9's will over lap, but you still end up with hole in bass sounds from 120hz to 80hz because spacific sounds have been assigned (by the sound track of a movie) to the LFE channle above 80hz.

You say "(setting the xo for the life output in the avr to 80hz)". Again, this control that we're talking about is a LOW PASS FILTER, not a crossover. A crossover consists of both a low pass and high pass filter. LPF of LFE does not redirect the bass to your other speakers, so if you set LPF of LFE to anything below 120Hz, that sound just gets thrown away. It doesn't go to, in your example, your mains... because it's a single filter, not a crossover.

What controls what you're talking about is the crossover for the mains themselves. There is no overlap. Let's use your example:
LPF of LFE = 80Hz.
Mains set to 60Hz.

In this case, the audio from the main channels down to 60Hz stays in the mains, then transfers over to the subwoofer. The audio from the LFE channel below 80Hz is sent to the sub... and the 80-120Hz audio in the LFE channel goes... wait for it... NOWHERE. It's just gone. It has been filtered away. There's no overlap because the audio from the LFE channel only goes to the mains in one specific setup configuration: When you don't have a subwoofer connected (and possibly if you use the AVR's "double bass" control with your mains set as large, which you really shouldn't). In the case of your example, the subwoofer output would equal redirected bass from the mains with the transition centered at 60Hz PLUS the LFE channel with 80-120Hz filtered away.

I think we're really beating a dead horse here, 'cause it has been explained in detail repeatedly. LPF of LFE should be set to 120Hz, no exceptions, or else you are throwing away audio the mixer intended you to hear.

jbooker82

Alright I got it. Just missed the part about the AVR being a Filter and not a XO. So it does make since that the 80hz to 120 would be lost.

cheddar

To try and summarize what's been said. Sometimes too much info isn't always better.

Two Important Bass Management options discussed:

1. Crossover point: Used to determine the point for other speakers to dump their lower frequencies to the subwoofer. Usually set at 80Hz, but can be set differently according to the capabilities of individual speakers.

2. LPF of LFE: Used to determine the point at which the subwoofer cuts off reproduction of higher frequencies. Set at 120Hz unless you have a subwoofer which can't handle frequencies in this range.

Just make sure you're setting the right bass management option for the right reason.

cheddar

And just because bass management settings aren't confusing enough, I should add that both bass management options are available at both the AVR/Pre AND the subwoofer depending on the model. So just because you've used the unfiltered connection and turned the subwoofer's LPF dial all the way to 120Hz 'just in case', doesn't mean there isn't an LPF of LFE setting in the AVR/Pre that also needs to be set to 120Hz.

Sometimes it's not just a matter of knowing what needs to be set, but where all the redundant options are for the same setting...:rolleyes: