The best x-overs??
- Thread starter MCLSOUND
- Start date
To set up a 4-way multi amp system can not just by a brand name x-over to have good result, it will depend on what kind of speakers and amps or effect of the room. so the the best way is use a selectable ( cross over point and curve ) with gain control first to find out what is the best in selected and change with a fixed to the same value. that is the way I did on my system
cheers
tony ma
cheers
tony ma
It looks to me like those are all analog crossovers that are card based or selections on the PCB with switches. Have you looked at any of the digital speaker control systems or are you keeping things only analog?? The advantage going digital is obvious as you have a lot more flexibility and processing options.
Rob
Rob
Hi
The very short answer is one that results in the desired response shape.
Conceptually dividing the frequency ranges is easy, a matter of setting the knobs or producing the right RLC combination's which even have names like Butterworth, Linkwitz Riley Bessel etc..
What you get when you sum them is ideally flat response but in the real world one uses crossovers WITH loudspeaker drivers, each of which also has it’s own magnitude and phase response.
When we have two signals adding together with resistors, the sum is a function of the magnitude AND phase of both signals. Phase matters critically because two equal but opposite phase signals sum to zero while if in phase double the voltage.. This is coherent addition in that there is only one result.
With an upper and lower frequency loudspeaker, what you want is them to also sum such that the result is a continuous response. Loudspeaker drivers CAN sum coherently like the resistor analogy, this happens when the sources are less than about 1 / 4 wavelength apart. Most are familiar that when you place two identical subwoofers close together, they can radiate 4X the acoustic power and have twice the total efficiency due to mutual coupling which happens when he sources combine coherently.
With multi-way loudspeakers the sources are normally too far apart to combine coherently into a single new source like the subwoofers do so they radiate as separate independent acoustic sources. That is why you have to be a certain distance away from most speakers before you can’t clearly hear the hi, mid and low origins.
Now, what you get is like before the sum of the drivers magnitude and phases plus the phase difference that results as you change positions left/ right and up /down.. Also In the case of an interference pattern interestingly, since it is not coherent, flipping the driver to one source does not cancel out the radiated sound power but simply re-arranges the pattern of lobes and nulls.
When two sources do not add coherently, they produce an interference pattern and this is true with most speakers too. The “sum” is a pattern of lobes and nulls and now the object is to make the main big lobe point forward at listening height more or less at through crossover. What you don’t want is the lobe and nulls to wave up and down as you traverse crossover.
The bottom line acoustically is that you pretty much need to be able to measure what you have.
The HUGE up side to this is that it has never been easier to take good quality measurements for a tiny fraction of what a new anything in the “hifi” world.
Personally, I use a TDS and ARTA for loudspeakers, if you’re interested at all, DO look into measurement software called ARTA. You need that and ideally a good quality USB audio interface (I have an M-audio fast rack pro I use for measurements and some recording) and a measurement microphone. A measurement mic is omni directional, has flat frequency response over a very wide band (and makes delightful mono recordings). Places like Madisound and Parts Express have reasonable priced entry level mics, Earthworks, ACO and B&K make very good measurement mics that cost more.
Also, consider stepping out of hifi, consider a pro-sound speaker controller, these range from pretty cheap Berhinger to really good for more like the Xilica’s. I have used Xilica’s for a number of things and like them a lot. The advantage here is that these offer a large amount of flexibility, most allow any high pass filter to be used with any low pass independent of slope, frequency, type etc.
Most allow each channel to be delayed electronically if time alignment is desired as well as most allow many bands of parametric eq if desired. The drivers may have a location error in X, Y or Z and while you can’t fix X or Y electronically Z is time and time delay is easy.
All of this is done in the DSP world and so some things can be done easily that cannot be done at all with circuitry. .
Real EQ and everything above that requires that you know what you are trying to fix via measurement, doing it by ear alone here is more like shooting bats in the dark blindfolded on the other hand, a corrupted measurement looks like a real measurement.
Pro-sound gear runs at a higher signal voltage too but once you have stepped up the hifi lever to pro-sound signal levels, then one can also use balanced signal cables and all your concerns about hum and esoteric signal wires vanish.
Anyway, consider getting a measurement set up before buying anything else, this way you will have a good idea what you have to work with.
Best,
Tom Danley
DanleySoundLabs
The very short answer is one that results in the desired response shape.
Conceptually dividing the frequency ranges is easy, a matter of setting the knobs or producing the right RLC combination's which even have names like Butterworth, Linkwitz Riley Bessel etc..
What you get when you sum them is ideally flat response but in the real world one uses crossovers WITH loudspeaker drivers, each of which also has it’s own magnitude and phase response.
When we have two signals adding together with resistors, the sum is a function of the magnitude AND phase of both signals. Phase matters critically because two equal but opposite phase signals sum to zero while if in phase double the voltage.. This is coherent addition in that there is only one result.
With an upper and lower frequency loudspeaker, what you want is them to also sum such that the result is a continuous response. Loudspeaker drivers CAN sum coherently like the resistor analogy, this happens when the sources are less than about 1 / 4 wavelength apart. Most are familiar that when you place two identical subwoofers close together, they can radiate 4X the acoustic power and have twice the total efficiency due to mutual coupling which happens when he sources combine coherently.
With multi-way loudspeakers the sources are normally too far apart to combine coherently into a single new source like the subwoofers do so they radiate as separate independent acoustic sources. That is why you have to be a certain distance away from most speakers before you can’t clearly hear the hi, mid and low origins.
Now, what you get is like before the sum of the drivers magnitude and phases plus the phase difference that results as you change positions left/ right and up /down.. Also In the case of an interference pattern interestingly, since it is not coherent, flipping the driver to one source does not cancel out the radiated sound power but simply re-arranges the pattern of lobes and nulls.
When two sources do not add coherently, they produce an interference pattern and this is true with most speakers too. The “sum” is a pattern of lobes and nulls and now the object is to make the main big lobe point forward at listening height more or less at through crossover. What you don’t want is the lobe and nulls to wave up and down as you traverse crossover.
The bottom line acoustically is that you pretty much need to be able to measure what you have.
The HUGE up side to this is that it has never been easier to take good quality measurements for a tiny fraction of what a new anything in the “hifi” world.
Personally, I use a TDS and ARTA for loudspeakers, if you’re interested at all, DO look into measurement software called ARTA. You need that and ideally a good quality USB audio interface (I have an M-audio fast rack pro I use for measurements and some recording) and a measurement microphone. A measurement mic is omni directional, has flat frequency response over a very wide band (and makes delightful mono recordings). Places like Madisound and Parts Express have reasonable priced entry level mics, Earthworks, ACO and B&K make very good measurement mics that cost more.
Also, consider stepping out of hifi, consider a pro-sound speaker controller, these range from pretty cheap Berhinger to really good for more like the Xilica’s. I have used Xilica’s for a number of things and like them a lot. The advantage here is that these offer a large amount of flexibility, most allow any high pass filter to be used with any low pass independent of slope, frequency, type etc.
Most allow each channel to be delayed electronically if time alignment is desired as well as most allow many bands of parametric eq if desired. The drivers may have a location error in X, Y or Z and while you can’t fix X or Y electronically Z is time and time delay is easy.
All of this is done in the DSP world and so some things can be done easily that cannot be done at all with circuitry. .
Real EQ and everything above that requires that you know what you are trying to fix via measurement, doing it by ear alone here is more like shooting bats in the dark blindfolded on the other hand, a corrupted measurement looks like a real measurement.
Pro-sound gear runs at a higher signal voltage too but once you have stepped up the hifi lever to pro-sound signal levels, then one can also use balanced signal cables and all your concerns about hum and esoteric signal wires vanish.
Anyway, consider getting a measurement set up before buying anything else, this way you will have a good idea what you have to work with.
Best,
Tom Danley
DanleySoundLabs
I am using a Pass XVR1 in CJ based system with an Iso Linear array speakers with 18 inch subs. The x over supplied with the speaker is digital bass mgt system with a switching pwr supply. It a balanced only design and my system is signal ended. I had 10HZ issues, ground loop problems, and woofer drag with the stock unit that could not be eliminated. The mfg did the speaker and x over set up at my studio but were in capable of fixing the issues.
The Pass xover solved all of my problems and I can highly recommend it.
The Pass xover solved all of my problems and I can highly recommend it.
Thanks all
Tony...I work in the Toronto area,would love to chat some time
Hi Tom....very informative...I have decided to go DIY with my speakers and have lots to learn. Would love to chat also some time Tom.
I picked up a Berringer 2496,and is all I have in the digital domain.
Tony...I work in the Toronto area,would love to chat some time
Hi Tom....very informative...I have decided to go DIY with my speakers and have lots to learn. Would love to chat also some time Tom.
I picked up a Berringer 2496,and is all I have in the digital domain.
Hi MCLSOUND
Welcome to join us, we are group of diy guys in east side of Toronto, mainly with tube amps, analog source, classical and light music,modifying , live recording with tape and most of us with multi amps system of horns or electric static speakers.
Tom is 100% right and he can have those equipments to measure because he is pro, but we diyer can only to use what in hand or add more to improve, the only way is to judge by our own ear if we have enough room to move those speaker's driver to match which like tom said shooting bats in dark- just joking
tony ma
If you are a DIY guy, the best crossover is the most flexible. If you also run a PC with Foobar, there is no more flexible crossover than this one:
http://xover.sourceforge.net/
It only works on the older version of Foobar, and on a WinXP machine.
I have learned A LOT using this. You can mix a Butterworth low-pass with a Chebychev high pass and hear how it sounds like when compared to a Bessel low-pass and a Butterworth high-pass. But, if you are a complete beginner to loudspeaker design, it could also totally confuse you because it is so flexible.
http://xover.sourceforge.net/
It only works on the older version of Foobar, and on a WinXP machine.
I have learned A LOT using this. You can mix a Butterworth low-pass with a Chebychev high pass and hear how it sounds like when compared to a Bessel low-pass and a Butterworth high-pass. But, if you are a complete beginner to loudspeaker design, it could also totally confuse you because it is so flexible.
MCL said “I have decided to go DIY with my speakers and have lots to learn. Would love to chat also some time Tom.
I picked up a Berringer 2496,and is all I have in the digital domain.”
Cool!, That is a comparatively inexpensive yet very powerful speaker controller and can do just about anything you will ever need to do crossover wise etc. I think you will enjoy the adventure although like a fractal, the deeper you get into it, the more you realize there is still more to it all and that doesn’t stop.
What you hear is ultimately what counts most BUT the problem is when speakers are sorta close, any change you make causes it to sound different, the problem is usually one recording or type of music sounds better this way and some other recording may sound worse. On the other hand, there is usually only one or a few crossover solutions which are correct from a signal point of view and being able to measure “is this closer than this” will allow one to find settings empirically MUCH faster than by ear.
I mentioned a program called ARTA, I have no connection to the company but would urge anyone interested in measuring and if they don’t have a modern measurement system, look at this program and it’s only $128.
It is VERY powerful even if it were 5X the price (to give an idea, in the early 80’s, the first TEF machine that did a few of the measurement ARTA does cost the company I worked for $11,000.00).
http://www.fesb.hr/~mateljan/arta/index.htm
And a measurement microphone like this at $55 (get two if you can so you can record and do generation loss tests on speakers.) If you can spend more on microphones, they will make better recordings and be more rugged, have less internal noise etc but these would get you going.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-625
And a decent usb interface with mic pre-amp and phantom power for mics like this one I use that works at 24/96khz;
http://www.m-audio.com/products/en_us/FastTrackPro.html
Anyway it will take some fiddling and reading to feel comfortable etc but there is no pressure so it’s fun.
Hi Tony, I might do this for a living but I am a DIY’r, I built tube amps and electrostatic speakers and to be sure, there was a time I didn’t think I could figure any of this stuff out, especially the math which was my worst subject in school.
Even now, one of my favorite things is assembling something new, it’s like a Heathkit except you aren’t sure how will work even if it’s built correctly.
The more I think about it, the more I think that pursuing things as your curiosity drives you may be slower than formal education but you are more likely to find new ways of doing things. I think more people should get involved, build things and there are few things that are as weird and interesting as sound and it’s capture and reproduction of the image.
C1 ferrari, I am not sure what bats you have but my bet would be that if you can get them high enough into the air, they still might be harder to hit on account of the black face plate, but blindfolded all bets are off haha.
Hi Gary
I have not tried that (windows / sound card) solution , I am a little leery given in my system I have “some power” on tap for a computer hiccup. I love Sourceforge though, I use a program called Stellarium, a planetarium software from there that is very nice and drives a telescope.
Best,
Tom Danley
I picked up a Berringer 2496,and is all I have in the digital domain.”
Cool!, That is a comparatively inexpensive yet very powerful speaker controller and can do just about anything you will ever need to do crossover wise etc. I think you will enjoy the adventure although like a fractal, the deeper you get into it, the more you realize there is still more to it all and that doesn’t stop.
What you hear is ultimately what counts most BUT the problem is when speakers are sorta close, any change you make causes it to sound different, the problem is usually one recording or type of music sounds better this way and some other recording may sound worse. On the other hand, there is usually only one or a few crossover solutions which are correct from a signal point of view and being able to measure “is this closer than this” will allow one to find settings empirically MUCH faster than by ear.
I mentioned a program called ARTA, I have no connection to the company but would urge anyone interested in measuring and if they don’t have a modern measurement system, look at this program and it’s only $128.
It is VERY powerful even if it were 5X the price (to give an idea, in the early 80’s, the first TEF machine that did a few of the measurement ARTA does cost the company I worked for $11,000.00).
http://www.fesb.hr/~mateljan/arta/index.htm
And a measurement microphone like this at $55 (get two if you can so you can record and do generation loss tests on speakers.) If you can spend more on microphones, they will make better recordings and be more rugged, have less internal noise etc but these would get you going.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-625
And a decent usb interface with mic pre-amp and phantom power for mics like this one I use that works at 24/96khz;
http://www.m-audio.com/products/en_us/FastTrackPro.html
Anyway it will take some fiddling and reading to feel comfortable etc but there is no pressure so it’s fun.
Hi Tony, I might do this for a living but I am a DIY’r, I built tube amps and electrostatic speakers and to be sure, there was a time I didn’t think I could figure any of this stuff out, especially the math which was my worst subject in school.
Even now, one of my favorite things is assembling something new, it’s like a Heathkit except you aren’t sure how will work even if it’s built correctly.
The more I think about it, the more I think that pursuing things as your curiosity drives you may be slower than formal education but you are more likely to find new ways of doing things. I think more people should get involved, build things and there are few things that are as weird and interesting as sound and it’s capture and reproduction of the image.
C1 ferrari, I am not sure what bats you have but my bet would be that if you can get them high enough into the air, they still might be harder to hit on account of the black face plate, but blindfolded all bets are off haha.
Hi Gary
I have not tried that (windows / sound card) solution , I am a little leery given in my system I have “some power” on tap for a computer hiccup. I love Sourceforge though, I use a program called Stellarium, a planetarium software from there that is very nice and drives a telescope.
Best,
Tom Danley
Tom, like you I do this for a living, but I'm a DIY'er at heart. I designed my own amps for loudspeaker development when I kept blowing up amps. Then a dealer heard the amps and wanted to sell them. Same thing with my cables
The windows/soundcard solution is great because you can model all sorts of crossovers very quickly and just sit there and play with different slopes that would be extremely difficult to realize in the real world because the values for inductors and capacitors are not available. Doing a what-if analysis with different ripple, it showed me that the best sounding crossovers may not be the best measuring or "classically correct".
The windows/soundcard solution is great because you can model all sorts of crossovers very quickly and just sit there and play with different slopes that would be extremely difficult to realize in the real world because the values for inductors and capacitors are not available. Doing a what-if analysis with different ripple, it showed me that the best sounding crossovers may not be the best measuring or "classically correct".
Hi Gary
My concern is that sound cards don’t always go down gracefully when something happens while speaker controllers don’t crash and normally mute when power flickers etc.
This is a concern when you have several kw on tap if needed.
Don’t get the wrong idea though, I use the computer extensively and without it and detailed measurements I would not have been able to make speakers that act like a single acoustic source, preserve a square wave over a broad band and only have one forward lobe, no pattern of lobes and nulls or phase shift at crossover, using higher order passive crossovers, which in hifi they say can’t be done..
Best,
Tom Danley
DanleySoundLabs.com
My concern is that sound cards don’t always go down gracefully when something happens while speaker controllers don’t crash and normally mute when power flickers etc.
This is a concern when you have several kw on tap if needed.
Don’t get the wrong idea though, I use the computer extensively and without it and detailed measurements I would not have been able to make speakers that act like a single acoustic source, preserve a square wave over a broad band and only have one forward lobe, no pattern of lobes and nulls or phase shift at crossover, using higher order passive crossovers, which in hifi they say can’t be done..
Best,
Tom Danley
DanleySoundLabs.com
Tom, like you I do this for a living, but I'm a DIY'er at heart. I designed my own amps for loudspeaker development when I kept blowing up amps. Then a dealer heard the amps and wanted to sell them. Same thing with my cables
The windows/soundcard solution is great because you can model all sorts of crossovers very quickly and just sit there and play with different slopes that would be extremely difficult to realize in the real world because the values for inductors and capacitors are not available. Doing a what-if analysis with different ripple, it showed me that the best sounding crossovers may not be the best measuring or "classically correct".
I suspect what simple FR wasn't showing you was how the phase of the filters interacted with the speakers. That looks like pretty cool SW; if you can choose the filter type it would allow you to try linear-phase vs. other types, equiripple, etc. Not to mention (so I shall) the almost infinite variety of slopes and pass/stop band frequencies and attenuations possible using digital FIR and IIR approximations...
I hope to get back into the DIY arena if I ever manage to retire and have more time (yeah, dreaming, on both "retire" and "more time", but a guy can dream, right?
)One of the nicest things about many of the digital "DSP" crossovers is that you can program in several scenes. That is each scene may have different slopes, frequencies and delays. Then you can get a willing helper switch scenes in a random order.
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