many of you have probably seen my other hi-vi b3s crossover question thread, a few ppl helped with it and for that i am thankful...
there is still one technical aspect of this project that i do not seem to understand...it deals with the use of an active subwoofer crossover vs. the use of a plate amp...
it says very specifically in the project details NOT to use a plate amps speaker level outputs as the high pass crossover for the b3s because it has some sort of impedence conflict that results in a peak...for this reason, an impedence flattening circuit must be added to protect the b3s...this is costly and therefore not recommended
however, it does say to use an active subwoofer crossover....maybe i am unfamiliar as to what this is, but i assume it to mean an active low pass crossover to keep the highs away from a subwoofer....now my question is, how does using an active subwoofer crossover work in this case? the two hivi b3s need some sort of high pass to protect them from overexcursion....do active subwoofer crossovers ALSO have high pass speaker outs? how do these high pass speaker outputs differ from a typical plate amps high pass speaker outs? how do these outs avoid creating an impedence conflict with these drivers?
sorry i am being a pest with this issue i just cant figure it out and im trying real hard to understand....thanks to all replies
EDIT: this is all in reference to this project: http://www.zaphaudio.com/audio-speaker18.html
there is still one technical aspect of this project that i do not seem to understand...it deals with the use of an active subwoofer crossover vs. the use of a plate amp...
it says very specifically in the project details NOT to use a plate amps speaker level outputs as the high pass crossover for the b3s because it has some sort of impedence conflict that results in a peak...for this reason, an impedence flattening circuit must be added to protect the b3s...this is costly and therefore not recommended
however, it does say to use an active subwoofer crossover....maybe i am unfamiliar as to what this is, but i assume it to mean an active low pass crossover to keep the highs away from a subwoofer....now my question is, how does using an active subwoofer crossover work in this case? the two hivi b3s need some sort of high pass to protect them from overexcursion....do active subwoofer crossovers ALSO have high pass speaker outs? how do these high pass speaker outputs differ from a typical plate amps high pass speaker outs? how do these outs avoid creating an impedence conflict with these drivers?
sorry i am being a pest with this issue i just cant figure it out and im trying real hard to understand....thanks to all replies
EDIT: this is all in reference to this project: http://www.zaphaudio.com/audio-speaker18.html
I can tell you what there is on *my* plate amp. for the high-pass crossover:
A single capacitor per channel. That's it. If you didn't build the amp or change the caps, you probably don't even know what value they are, nevermind the quality... This is a "passive" crossover... no transistors, no op-amps.
An active filter will have whatever input and output cutoff frequencies you design into it. An active filter will have an input impedance way, way, way higher than this sort of thing and will likely not mess with the signal anything like as much.
HTH
-David
A single capacitor per channel. That's it. If you didn't build the amp or change the caps, you probably don't even know what value they are, nevermind the quality... This is a "passive" crossover... no transistors, no op-amps.
An active filter will have whatever input and output cutoff frequencies you design into it. An active filter will have an input impedance way, way, way higher than this sort of thing and will likely not mess with the signal anything like as much.
HTH
-David
so active crossovers have a higher input impedence, which means it wont conflict with the drivers....
passive crossovers, such as a simple capacitor, do not have high input impedences and therefore need an impedence flattening circuit to prevent any bad things from harming the drivers...
is that it?
EDIT: does HTH mean happy to help, cuz if it does, then thank you for helping, and if it doesnt....well....thanks for helping
passive crossovers, such as a simple capacitor, do not have high input impedences and therefore need an impedence flattening circuit to prevent any bad things from harming the drivers...
is that it?
EDIT: does HTH mean happy to help, cuz if it does, then thank you for helping, and if it doesnt....well....thanks for helping
I don't know if you are powering these 3 inchers from a receiver or from a separate pre amp/power amp combo. If you have access to the signal line BEFORE it hits the main amp section- a preamp/power amp combo has easy access, a receiver will have to be opened up and traced down-you can use the Passive Line Level Xovers at our own Planet 10's site.
Although the word "passive" is used in the title, the fact is that if you put a passive filter BEFORE the final amplifying device-whether it is tube or transistor-you now have an active filter.
That is what this section shows you how to do.
It is probably a good idea to use these with a solid state device, be it receiver or separate amp, than a tube amp, since solid state amps usually have higher input impedance than tubes.
You can check back with us to make sure the math is correct. I have not used one, but I have not heard anything bad about them, either.
Although the word "passive" is used in the title, the fact is that if you put a passive filter BEFORE the final amplifying device-whether it is tube or transistor-you now have an active filter.
That is what this section shows you how to do.
It is probably a good idea to use these with a solid state device, be it receiver or separate amp, than a tube amp, since solid state amps usually have higher input impedance than tubes.
You can check back with us to make sure the math is correct. I have not used one, but I have not heard anything bad about them, either.
What is meant by use an active subwoofer crossover is that you should split the signal into high and low before it is amplified (at "line level" using active (transistorised) components). If you have a surround sound processor you will be able to do this with the unit, the "sub-out" rca jack on the back of the unit will be a line level signal that will be just the low frequencies and the signal to your main speakers will be just the higher frequencies. The main speaker out connections on the back of the receiver will have all the appropriate signal processing done and all you have to do is connect your new speakers up using speaker wire. For the sub you would take an rca interconnect cable and connect that to the amplifier you are using to power the subwoofer. That amp will be the plate amp un the sub if it is powered, or a separate power amp if your sub is not powered. If you do not have a processor (or home cinema receiver) you will have to build a line level crossover that will split the signal into a sub 150hz line lever (non amplified) signal to go to a separate amplifier to power your woofer. This unit will also provide a line level stereo output of the >150hz signal for you to feed into your amplifier before going to your speakers. You will have to purchase or build an an electronic crossover to do this. If you are having difficulty trying to work out what is meant by active crossovers and how to integrate a sub using one, then perhaps it would be better to buy a crossover rather than build one yourself. In any case, I think you will probably get better help if you can tell us what your existing stereo components are so we can try to help you sort out what you will need to buy and how to set it up.
Good luck!
chrish
Good luck!
chrish
wow! that link, and both posts, are really pointing me in the right direction....
my situation is as follows: these speakers are for use with my computer....i have a soundcard with rear speaker outputs and front speaker outputs....it also has a channel with center/sub out written on it, but i cant get that one to work so i assume its busted or i am an idiot....either way, i have more than one output, and it would be possible for me to use a passive line level crossover on either or even both...
the sub is part of an existing logitech computer speaker system...not the best, but it will do seeing as i need only a little low end extension from these drivers...i can hook it up to the rear speaker outs
the hi-vi b3s will be run by an aiwa minisystem with about 30 watts per channel....the minisystem will be recieving the signal via RCA cable coming from the front speaker out on the soundcard....
so...according to what u tell me, it IS possible to bypass using an extensive impedence flattening circuit if i put a crossover on the RCA cables? the circuits on the link given previously seem pretty simple and wouldnt be that expensive to build, so i am definately interested
all i need to figure out now is:
-exactly where i want to cross them over (what freq)?
-exactly HOW i would go about hooking up a resistor and capacitor to RCA cables?
i am thinking first order at either 200-250 Hz
my situation is as follows: these speakers are for use with my computer....i have a soundcard with rear speaker outputs and front speaker outputs....it also has a channel with center/sub out written on it, but i cant get that one to work so i assume its busted or i am an idiot....either way, i have more than one output, and it would be possible for me to use a passive line level crossover on either or even both...
the sub is part of an existing logitech computer speaker system...not the best, but it will do seeing as i need only a little low end extension from these drivers...i can hook it up to the rear speaker outs
the hi-vi b3s will be run by an aiwa minisystem with about 30 watts per channel....the minisystem will be recieving the signal via RCA cable coming from the front speaker out on the soundcard....
so...according to what u tell me, it IS possible to bypass using an extensive impedence flattening circuit if i put a crossover on the RCA cables? the circuits on the link given previously seem pretty simple and wouldnt be that expensive to build, so i am definately interested
all i need to figure out now is:
-exactly where i want to cross them over (what freq)?
-exactly HOW i would go about hooking up a resistor and capacitor to RCA cables?
i am thinking first order at either 200-250 Hz
The subwoofer channel, is it not working with a subwoofer driver's voice coil hooked straight up to it, or is it not working as the input to a sub amplifier? Is there a software setting to turn on the output from that connector? It would not be surprising to have a software switch setting for straight stereo or "2.1" output, with the sub out disabled in stereo.
the 2.1 logitech system i have right now is all run thru the same 1/8" jack....i tried finding some way to switch it on, while having that 1/8" plug plugged into the center/sub out jack...and it didnt work....maybe if i had an independent subwoofer without the 2 satellites, it could work then...
i found another problem as well...those calculations assume i know the input impedence of the amplifier, but i do not know what that is....
the specs of the amp are found here...page 22 on this PDF file shows different specs....
http://www.eu.aiwa.com/no/pdf/former_manuals/ZL100EZE.PDF
how the heck am i gonna figure out what the input impedence is? cuz i cant calculate high pass crossovers without it
EDIT: the soundcard is soundblaster live! 5.1 digital
i found another problem as well...those calculations assume i know the input impedence of the amplifier, but i do not know what that is....
the specs of the amp are found here...page 22 on this PDF file shows different specs....
http://www.eu.aiwa.com/no/pdf/former_manuals/ZL100EZE.PDF
how the heck am i gonna figure out what the input impedence is? cuz i cant calculate high pass crossovers without it
EDIT: the soundcard is soundblaster live! 5.1 digital
Look into http://kxproject.lugosoft.com/index.php?skip=1. Those are drivers for creative sound cards that are supposed to let you set up any crossovers that you might want.
I have a dell 5.1 SB, and I never got the drivers to work with that, so I can't really say how well it works. If it's an original creative card, then the drivers should work. Anybody that knows more about this, please help out.
I have a dell 5.1 SB, and I never got the drivers to work with that, so I can't really say how well it works. If it's an original creative card, then the drivers should work. Anybody that knows more about this, please help out.
I have used KX drivers with an Audigy 2 successfully - only actually to reduce VI latency in Cubase VST.
All the outputs change on the card - IIRC, the main output is now line in. It can be remapped using the software but I never bothered - it's a lot easier to just plug the connector into a different socket...
It takes a bit of messing about to set everything up but it's a really flexible system.
The KX forums are pretty helpful too.
All the outputs change on the card - IIRC, the main output is now line in. It can be remapped using the software but I never bothered - it's a lot easier to just plug the connector into a different socket...
It takes a bit of messing about to set everything up but it's a really flexible system.
The KX forums are pretty helpful too.
jaygeorge1979 said:
If you can get the kx drivers to work, you don't need to know the input impedence. All the crossovers would be done digitally by the drivers, so all you would need to do then is connect the sound card to the amps.
Do you have an original creative card or did it come with the computer (such as dell...)?
Hi,
you need to get the sound card working correctly.
You need it set to 2.1 . Left, Right and Sub.
You then follow the c/o instructions in the original article.
Set the front c/o on the soundcard according to the article.
Probably involves setting the fronts to "small".
Setting this correctly will divert the bass on stereo material
to the Sub output.
Perhaps this why your sub output appears not to be working.
The front outputs on the card go to the Aiwa.
The speakers are connected directly to the Aiwa.
The soundcards sub output goes to your sub.
You need to set volume levels on the sub
and the Aiwa and leave them there.
You adjust the volume via the PC.
Note that you cannot use any other functions of the Minisystem.
It would be acting as a fixed gain stereo power amplifier.
If you do use the other functions you will drive the speaker full range.
/sreten.
you need to get the sound card working correctly.
You need it set to 2.1 . Left, Right and Sub.
You then follow the c/o instructions in the original article.
Set the front c/o on the soundcard according to the article.
Probably involves setting the fronts to "small".
Setting this correctly will divert the bass on stereo material
to the Sub output.
Perhaps this why your sub output appears not to be working.
The front outputs on the card go to the Aiwa.
The speakers are connected directly to the Aiwa.
The soundcards sub output goes to your sub.
You need to set volume levels on the sub
and the Aiwa and leave them there.
You adjust the volume via the PC.
Note that you cannot use any other functions of the Minisystem.
It would be acting as a fixed gain stereo power amplifier.
If you do use the other functions you will drive the speaker full range.
/sreten.i am currently battling with the creative surround mixer...when i click "speakers" it only gives me 2 speaker, 4 speaker, and headphone options...everywhere i am reading it tells me to select the 5.1 option here, but there isnt one...when i click on settings, i see options to adjust center, subwoofer, and crossover freq, but they dont work! probably because 5.1 isnt selected...but i cant find the option...did i get the wrong software?!?!
Re: Slightly OT
Could you use a USB soundcard or does it have to be internal?
Creative Extigy or similar maybe?
http://us.creative.com/products/product.asp?category=1&subcategory=207&product=585
trunkmonkey said:
Could you use a USB soundcard or does it have to be internal?
Creative Extigy or similar maybe?
http://us.creative.com/products/product.asp?category=1&subcategory=207&product=585
yes i downloaded kxproject but i dont know what FX pack is? it allows me to use a mixer, etc....but there is no sound...i think maybe it isnt mapped to the right soundcard? it is an aftermarket soundcard, installed it about 2 months ago...it works fine without kxproject despite the fact that i cant get 5.1 sound...just 2 speaker or 4 speaker
i am gonna tinker with kx more....does anybody know how to measure the input impedence of an amplifier?
i am gonna tinker with kx more....does anybody know how to measure the input impedence of an amplifier?
Go into multimedia / sounds and audio in the control panel, you may need to set the recording and playback devices and should also be able to set 5.1 under the speaker settings.
Try different outputs / inputs on the card or remap the outputs using the KX mixer app. It may be worth asking on the KX forum for a step by step but because this isn't something I did, I can't be more helpful I'm afraid. There are details on how to do the initial setup on the KX site.
The FX pack contains the crossover and a load of other plugins.
Try different outputs / inputs on the card or remap the outputs using the KX mixer app. It may be worth asking on the KX forum for a step by step but because this isn't something I did, I can't be more helpful I'm afraid. There are details on how to do the initial setup on the KX site.
The FX pack contains the crossover and a load of other plugins.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.