X-Fi Bass Redirection and your A/V receiver - How it works

Ok, this is my understanding of how the X-Fi Bass redirection works. It's actually not a crossover setting of your speakers, but just a crossover for your subwoofer/lfe channel. The crossover setting in bass redirection is just like the lpf to lfe crossover, which only effects the subwoofer in your a/v equipment. The small and large speaker settings then determines whether to apply the crossover setting on your A/V receiver. So, if set to large, the a/v receiver's crossover for that certain set of channels will not be applied. When set to small, then the a/v receiver's crossover settings are applied. Nothing to do with the bass redirection crossover, because that is just for the lfe channel, which is the sub and no double crossover with a/v receiver. To sum it all up, find out your subwoofer's frequency range and then set your sub to crossover at the higher limit. This will overlap with the speakers seperate crossover settings on your a/v receiver and produce a nice broad range sound.

eg: fronts set to 80hz in a/v receiver - set small for fronts x-fi

Center set to 80hz in a/v receiver - set small for center in x-fi

Surrounds set to 120hz in a/v receiver - set small for surrounds in x-fi

Subwoofer - set lfe crossover to 120hz

eg2: fronts set to 120hz (sattelites) in a/v receiver - set small for fronts x-fi

Center and surrounds set to 120hz in a/v receiver - set small for cent/surr in x-fi

Subwoofer - set lfe crossover to 120hz or 150hz so this will overlap the satts a bit.

eg 3: fronts set to Full range in a/v receiver - set large for fronts in x-fi

center and surrounds set to 80hz in receiver - set to small for cent/surr in x-fi

Subwoofer - set lfe crossover to 80hz

regards,
RagDoll.

 

The bass redirection, filters bass away from the sats output and to the sub output. You can further filter it at the receiver if you wish. It is generally best to know the cutoffs as you said as it helps dial in the system properly.

 

thanks for that info.i have all the settings you mentioned in my receiver,however within the auzentech prelude,only the the sub setting can be adjusted,not any of the other speakers?

 

Hey man.
We have same system LOL.
Today I am going to buy cables after work to connect my Forte to my home theater receiver through analog cables.
@RagDoll.
I am not really knowledgeable in this. When you mentioned that speakers need to be changed to small. Did you mean it needed to be done in the receiver settings or somewhere in Windows or Sound card properties.
Thank you.

 

there are no settings as such within the auzen software that i can find,nor the windows sound properties.
for connection i am using the optical out from the card to the receiver.

 

You can set them in windows too, right click speaker icon in bottom right, then playback devices. Then click on speakers, then configure. Run through the prompts and then deselect full range so it's not ticked and you will see the speakers pictures stay small.

regards,
RagDoll.

 

What I'm trying to explain to you is that it is an independant crossover, just for the lfe/sub channel. It isn't the same as the crossover setting for speakers in your a/v receiver. Why would creative make it so 2 crossover settings be applied?

regards,
RagDoll.

 

Bass redirection isnt for the LFE channel.

It is the subwoofer + speakers crossover frequency and the subs volume control.
Bass is being redirected from speakers set to Small, to the subwoofer, it has no effect on speakers set to Large.
The crossover point is the lowest frequency sent to the (small) speakers and the highest frequency sent to the sub from that speaker channel (at -3dB, -6dB, whatever order filter they use).

The LFE channel doesnt need a crossover, its only bass and you want to hear everything on that channel, so theres no point in filtering it.
For this reason, when your sub is connected to a cinema system, you should turn off the crossover on your subwoofer or set it to max frequency.

The sub volume level control in 'bass redirection' still applies to the LFE channel, just the crossover has no effect.

When using bass redirection, both LFE and redirected bass go to the sub.

ps good topic, it took me a while to work it out, what with my speaker channels periodically switching around, chasing ghosts I was.

 

Sorry Muff, but that's incorrect, I have been doing alot of reading about the specifics of the x-fi bass redirection. If your understanding is right, that would effectively create 2 crossovers, one on the x-fi and one on the a/v receiver. That would actually cause interference in sound and creative didn't design it's bass redirection to do that. It is used to work with an a/v receiver together. Small and large speaker settings affect the speakers and the subwoofer crossover is just for the sub/lfe...

regards,
RagDoll.

 

If using digital out from the PC, the redirection crossover might be applied I'm not sure.
If so, you should use either the amps DSP or the X-Fi, not both.

I'm talking about using analogue out (the main reason for having a quality card).
I use analogue direct through my AV amp so there is no processing performed on the analogue signal at all except volume control.
All processing is performed by the X-Fi Prelude.

No matter which way you connect, you should use only one sound processor unless you are careful how you mix and match them.

 

I agree, and I'm using multi analogue aswell, I figured all this out when I got my High Quality DVD audio and SACD player. Hooked up via multi analogue and it has a small and large speaker setting and sub on/off setting. I read in the manual and on various websites that the small setting, then uses the a/v receiver's crossover and the large doesn't just sets it to full range. There is no crossover setting on the dvd player, yet through analogue, it uses the a/v receiver's settings. The same with the soundcard's small and large/full range settings. Only difference is that it has a separate crossover for the lfe on a soundcard, which only applies to the sub.

regards,
RagDoll.

 

There is some confusion.

Small means you have smaller box speakers that dont do deep bass very well.
Bass is redirected to the subwoofer, using the crossover in 'bass redirection'.

Large means you have a large box full range speaker and wish to send all frequencies to the speakers.
Large is used if you want to bypass the X-Fis bass redirection crossover.
Because all frequencies are sent to the amp, you can use the amps DSP without worry.

 

Bass is being redirected to the lfe/sub channel at a certain crossover frequency independant of the speakers. Large goes through to the a/v receiver and then the a/v receiver applies the full range setting, small gets sent to the receiver and the a/v receiver applies a crossover at a certain frequency. Remember, the lfe crossover only affects the sub. This is why flexbass in asus and auzentech say lfe crossover frequency. Just that creative left out the label of lfe, doesn't mean it's not just the lfe. Look up flexbass, which does exactly the same thing.

regards,
RagDoll.

 

Large = ignore X-fi crossover
(Use the amps DSP if you wish)

Small = use X-fi crossover to redirect bass, you should turn off bass redirection on your amp.
Small cannot instruct the amplifier what to do, the amp cant automatically apply a crossover when you set speakers to small on the PC.

Thats it basically.

 

Sorry bro, but that doesn't make sense in terms of the way small and large works. What you're saying is that the small and large settings in my dvd player somehow make up their own crossover settings? My dvd player is hooked up in regards to it's audio, exactly how my sound card is. However, there is no crossover setting in the dvd player??? How would it know what crossover to set it to just by changing the small and large setting on the dvd player???

regards,
RagDoll.

 

Your DVD player is a different issue.
Check the manual to see how they have used the terms, they arent always the same.

I have all along been talking about using bass redirection on the X-Fi and how it works.
Not the DVD player or amp.
I'm talking about sound from your PC to the amp and how bass redirection on the X-fi works works.

 

Yes, me too, but the 2 are very similar, there are no issues with the dvd player...

 

It functions as said in post #14 though

AV amps follow the same method
Large = full range to the speaker
Small = send speakers bass to the sub.

You dont want to use bass redirection on your amp anyway if you have a decent soundcard.
You will be using analogue so you dont want the amp processing your nice signal otherwise it will have to convert it back to digital and then back to analogue again, making it pointless having a nice soundcard.

 

I guess we will have to agree to disagree on this one Muff

crossovers for the speakers, are different to the crossover of the lfe channel...

regards,
RagDoll.

 

Dude, its not up for debate, what I have stated is the way it works.

There isnt a crossover on the LFE channel within the X-Fi
LFE is the .1 channel which is connected to the subwoofer.
Movies, 5.1 music etc use the LFE channel, stereo doesnt make any use of it.
The sound coming through the LFE channel is not changed by any of the bass redirection settings.

forgot to add:
What bass redirection is doing is adding speaker bass signals to the LFE channel.
The LFE channel now contains LFE + redirected bass so isnt strictly only an LFE channel.
It has to have a label though.

The bass redirection crossover doesnt apply to the whole channel, it applies to redirected signals coming from other speakers which are added to the channel.