Crossover Question

ROBSCIX · Sep 16, 2005, 10:39 PM

I own the logitech Z-640 speakers, I was curious as to what the Exact Crossover Frequency was between the Satelites and the Subwoofer. I wanted this info so I could set my bass redirection Accurately. Now I do remember seeing this info somwhere but I can't remember. Now I decided to contact Logitech for the info..after awhile of waiting I was told that that info is proprietary and I could NOT be told what the frequency is!? Can you believe that? Now I could be wrong but I could swear it was in my speaker manual..but I can't be positive...Any ideas guys?..

JohnMcClane · Sep 19, 2005, 02:52 PM

You don't need to set bass-redirection for Logitech speakers as they have a hardware crossover. But to answer your question, as far as I know my old Z-680 sub had a crossover of 150hz - I guess the Z-640 will not differ much.

ROBSCIX · Sep 19, 2005, 04:40 PM

HA, yeah I was trying to listen for it..when moving slider for bass redirection and thats about where I pegged it at..about 150Hz give or take 5hz. SO what are you saying I shouldn't use Bass redirection? I figured if I set the bass redirection to the same freq. as the hardware crosssover than it would be optimal..meaning my sound card would be sinding signal in a optimal fashion. all Bass freq. that the system is designed for and non going to my sats. does this make sense? I hope you understand what I am trying to do..thx for your advice..

JohnMcClane · Sep 20, 2005, 10:20 AM

It depends on witch drivers you are using. If you are using kx drivers, then it should not make any difference whether you enable bass redirection or not. When using creative drivers you should have less bass with bass redirection enabled, because creative lowers it's sub output by 10db. With my current speakers, I get no sub output at all without bass redirection, but with my Logitech I never used it. That's also what I suggest you to do - let the speakers handle it (your sats will not get any freq's they can't handle)

ROBSCIX · Sep 20, 2005, 04:52 PM

Yeah thats what I thought. I use KX, so if I enable the sub output and set bass redirection it is essentially sending my sub MORE bass then the system was disigned for correct? So your saying with logitech I should leav the sub output off as well? and just let the hardware crossover handle it? When I set the Bass redirection though it gets pretty deep. I guess thats because it's sending signals from the sats..like they are designed for and also what has been filtered by bass redirection correct? SO just leave it off?

JohnMcClane · Sep 20, 2005, 07:17 PM

Quote:

...so if I enable the sub output and set bass redirection it is essentially sending my sub MORE bass then the system was disigned for correct?

No. It does the same as your hardware crossover. If you want to use bass-redirection, I suggest you use the 4th order crossover plugin as it is more accurate than the surrounder.

Quote:

So your saying with logitech I should leav the sub output off as well?

No, you should have this option enabled.

Quote:

When I set the Bass redirection though it gets pretty deep. I guess thats because it's sending signals from the sats..like they are designed for and also what has been filtered by bass redirection correct? SO just leave it off?

Yes leave it off. Your speakers will always use the hardware crossover. There is no way you can override or disable the internal crossover, so it makes to sense to use a software crossover. In fact this is why I sold my Logitech - I thought that the crossover freq. was too high and the subwoofer was way too loud (even at the lowest level).

ROBSCIX · Sep 20, 2005, 08:15 PM

Well Thats why I use the redirection, it seems to let me tune in my sub a little more. I understand though. What is the Bass redirection for then? If I decide to use the 4th order filter..is that UFX or stock KX?..so I have to remove surrounder all together?..BTW I appreciate you clearing up this info for me as it was always a bit of a grey area. People have always reccomended to me to use the redirection. it does add more bass...so can you explain when to use it? what is a really good way to dial in my bass then besides using redirection in surrounder? Thx again..

JohnMcClane · Sep 20, 2005, 09:52 PM

Quote:

What is the Bass redirection for then?

For speakers without hardware crossover, like mine

Quote:

so can you explain when to use it?

You can use it to choose a higher crossover freq. than your speakers crossover. For example:

Selecting a crossover of 120hz in software in combination with speakers without hardware crossover, would send all freq's below 120hz to your sub and all freq's above to your satellites. But that is not true with your speakers, because they have an internal crossover of ~150hz, your sub will get all freq's below 150hz and your satellites will get all freq's above 150hz, even though you set a crossover of 120hz in software. But if you set a higher crossover e.g. 200hz in software then your sub will play all freq's below 200hz and your sat's all freq's above 200hz. So you can use bass-redirection only to force a higher crossover frequency - I hope you understand what I mean.

Quote:

If I decide to use the 4th order filter..is that UFX or stock KX?..so I have to remove surrounder all together?

The 4th order crossover should be in the standard kx package. No you don't have to remove surrounder. Just untick bass-redirection in surrounder and add one or more 4th order crossover(s) after the surrounder plugin.

BTW. take a look at http://my.kxproject.com - there are a few presets using 4th order crossover

ROBSCIX · Sep 20, 2005, 11:00 PM

Yeah I understand perfectly, I used the bass redirection to figure out exactly what the FREQ is and it's ~150..I usually set the redirection at 200hz..but I used to set it 100Hz...if it was set that low would it put more bass info to the SUB?..ok I guess i wuill just leave it off..case closed thanks for the info..cleared things up nicley.

Sep 16, 2005, 10:39 PM	#1
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Crossover Question I own the logitech Z-640 speakers, I was curious as to what the Exact Crossover Frequency was between the Satelites and the Subwoofer. I wanted this info so I could set my bass redirection Accurately. Now I do remember seeing this info somwhere but I can't remember. Now I decided to contact Logitech for the info..after awhile of waiting I was told that that info is proprietary and I could NOT be told what the frequency is!? Can you believe that? Now I could be wrong but I could swear it was in my speaker manual..but I can't be positive...Any ideas guys?..

Sep 19, 2005, 02:52 PM	#2
JohnMcClane DriverHeaven Lover Join Date: May 2003 Location: Vienna, Austria Posts: 146 Rep Power: 0	You don't need to set bass-redirection for Logitech speakers as they have a hardware crossover. But to answer your question, as far as I know my old Z-680 sub had a crossover of 150hz - I guess the Z-640 will not differ much.

Sep 19, 2005, 04:40 PM	Thread Starter #3
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	HA, yeah I was trying to listen for it..when moving slider for bass redirection and thats about where I pegged it at..about 150Hz give or take 5hz. SO what are you saying I shouldn't use Bass redirection? I figured if I set the bass redirection to the same freq. as the hardware crosssover than it would be optimal..meaning my sound card would be sinding signal in a optimal fashion. all Bass freq. that the system is designed for and non going to my sats. does this make sense? I hope you understand what I am trying to do..thx for your advice..

Sep 20, 2005, 10:20 AM	#4
JohnMcClane DriverHeaven Lover Join Date: May 2003 Location: Vienna, Austria Posts: 146 Rep Power: 0	It depends on witch drivers you are using. If you are using kx drivers, then it should not make any difference whether you enable bass redirection or not. When using creative drivers you should have less bass with bass redirection enabled, because creative lowers it's sub output by 10db. With my current speakers, I get no sub output at all without bass redirection, but with my Logitech I never used it. That's also what I suggest you to do - let the speakers handle it (your sats will not get any freq's they can't handle)

Sep 20, 2005, 04:52 PM	Thread Starter #5
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Yeah thats what I thought. I use KX, so if I enable the sub output and set bass redirection it is essentially sending my sub MORE bass then the system was disigned for correct? So your saying with logitech I should leav the sub output off as well? and just let the hardware crossover handle it? When I set the Bass redirection though it gets pretty deep. I guess thats because it's sending signals from the sats..like they are designed for and also what has been filtered by bass redirection correct? SO just leave it off?

Sep 20, 2005, 08:15 PM	Thread Starter #7
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Well Thats why I use the redirection, it seems to let me tune in my sub a little more. I understand though. What is the Bass redirection for then? If I decide to use the 4th order filter..is that UFX or stock KX?..so I have to remove surrounder all together?..BTW I appreciate you clearing up this info for me as it was always a bit of a grey area. People have always reccomended to me to use the redirection. it does add more bass...so can you explain when to use it? what is a really good way to dial in my bass then besides using redirection in surrounder? Thx again..

Sep 20, 2005, 11:00 PM	Thread Starter #9
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Yeah I understand perfectly, I used the bass redirection to figure out exactly what the FREQ is and it's ~150..I usually set the redirection at 200hz..but I used to set it 100Hz...if it was set that low would it put more bass info to the SUB?..ok I guess i wuill just leave it off..case closed thanks for the info..cleared things up nicley.