It's funny to see some people avoiding crossovers in multi-way systems because they don't appreciate the sonic advantages of a properly aligned system but they can appreciate the sonic advantages of a lack of components in the signal path...
I'm of that other kind of people that enjoy alignment, proper filtering and equalisation, but don't notice at all things like exotic capacitors or op-amps. However, don't get me wrong, I'm not glad at all about that. It has always given me a lot of work and headaches (not to mention the amount of power electronics, filter and acoustics knowledge that I have been forced to gather and apply in order to tame sound and get a bit of pleasure
).
Actually, I would be very glad if I could get pleasant listening experiences from some drivers thrown in an open baffle without any crossover, some S.E. minimalistic amplifiers of those featuring open loop operation, tons of 2nd harmonic and unity damping factor, and some exotic sound source... Do you imagine? It has to be wounderful to not have to think in electronics, closed loop stability, filters, acoustics and enclosures in order to get your goals...
I'm of that other kind of people that enjoy alignment, proper filtering and equalisation, but don't notice at all things like exotic capacitors or op-amps. However, don't get me wrong, I'm not glad at all about that. It has always given me a lot of work and headaches (not to mention the amount of power electronics, filter and acoustics knowledge that I have been forced to gather and apply in order to tame sound and get a bit of pleasure
).Actually, I would be very glad if I could get pleasant listening experiences from some drivers thrown in an open baffle without any crossover, some S.E. minimalistic amplifiers of those featuring open loop operation, tons of 2nd harmonic and unity damping factor, and some exotic sound source... Do you imagine? It has to be wounderful to not have to think in electronics, closed loop stability, filters, acoustics and enclosures in order to get your goals...
Believe it or not, it's easier than aligning a passive system. You are likely to get the same result both ways if you don't know what you are doing, though.
Try to make these two "things" sum properly with passive filters, I tried but I couldn't...
It took me a 1500Hz 4th-order state-variable filter (with all the four tuning resistors having different values in order to equalise) and four custom-tuned first-order all-pass filters (phase-shifters) to make them sum well enough so that you can clearly hear the notch effect at 1500Hz perfectly on-axis when you invert the polarity of one of the drivers.
Eva,
yes it is very difficult to build speakers active and passive. Personally I leave speaker building to people that have done so all their life, it's like building an instrument and I ain't doing it. But hey, I am happy for you.
Probably the closest I can do is to try a fullrange driver and a Pass amp.
Thread like these give the newbies the impression that any idiot can slop a couple of filters together, a few amps and drivers and bypass all that BSing and voicing of the passive speakers.
The one thing abut passive speakers is that the response is largely fixed. How do you go about that with active speakers? Get a microphone and run sweeps everytime you change the volume until the response is flat? That game gets old quickly.
I remember what Nelson was saying about his active crossover how many millions possiblity you have to adjust it. Probably a hand full will give you the right sounds for the drivers. If you can get that on the first try I am going to call you when I play the lottery.
yes it is very difficult to build speakers active and passive. Personally I leave speaker building to people that have done so all their life, it's like building an instrument and I ain't doing it. But hey, I am happy for you.
Probably the closest I can do is to try a fullrange driver and a Pass amp.
Thread like these give the newbies the impression that any idiot can slop a couple of filters together, a few amps and drivers and bypass all that BSing and voicing of the passive speakers.
The one thing abut passive speakers is that the response is largely fixed. How do you go about that with active speakers? Get a microphone and run sweeps everytime you change the volume until the response is flat? That game gets old quickly.
I remember what Nelson was saying about his active crossover how many millions possiblity you have to adjust it. Probably a hand full will give you the right sounds for the drivers. If you can get that on the first try I am going to call you when I play the lottery.
Re: This unit, the SKA i really do not know....cannot say nothing about it
SKA = Simple Killer Amp, is an amplifier by amplifierguru
There are a couple of threads about it in forum:
Simple Killer Amp!
you, destroyer X have posted in very same thread: http://www.diyaudio.com/forums/showthread.php?postid=778411#post778411
Simple Killer Amp - Listening impressions
and amplifierguru website with 'SKA' info:
http://members.dodo.com.au/~gregball/guru_001.htm
destroyer X said:
SKA = Simple Killer Amp, is an amplifier by amplifierguru
There are a couple of threads about it in forum:
Simple Killer Amp!
you, destroyer X have posted in very same thread: http://www.diyaudio.com/forums/showthread.php?postid=778411#post778411
Simple Killer Amp - Listening impressions
and amplifierguru website with 'SKA' info:
http://members.dodo.com.au/~gregball/guru_001.htm
Actually some methods may be derived to align active or passive systems. I've already mentioned one of the most useful tools: A switch resting in your hand and allowing you to toggle the polarity of one of the drivers while you listen (whitout even blinking 
). Then, you have to tune the filters until you get the desired result, that is usually a flat versus notch effect on-axis at the crossover frequency when toggling.
How the filter has to be tuned depends a lot on the difference in response that may be heard when toggling polarity, but the exact criteria is rather hard to explain. I use potentiometers and sockets in order to be able to change component values quickly. Several potentiometers may be attached with wires to a socket and placed in another socket in the filter PCB. Then it's very easy to tune the potentiometers until the desired value is found, and finally, the potentiometer socket may be replaced by another socket with the proper resistors attached.
Using straight-from-the-book alignments for filters (passive or active) usually yields poor results.
). Then, you have to tune the filters until you get the desired result, that is usually a flat versus notch effect on-axis at the crossover frequency when toggling.How the filter has to be tuned depends a lot on the difference in response that may be heard when toggling polarity, but the exact criteria is rather hard to explain. I use potentiometers and sockets in order to be able to change component values quickly. Several potentiometers may be attached with wires to a socket and placed in another socket in the filter PCB. Then it's very easy to tune the potentiometers until the desired value is found, and finally, the potentiometer socket may be replaced by another socket with the proper resistors attached.
Using straight-from-the-book alignments for filters (passive or active) usually yields poor results.
"Active" crossover don`t necessarily mean the stages must be active. You could do sort of a "passive active" crossover.
Just scale up/down the passive filter parts for, let`s say, 600Ohms load impedance. Place the filters between the pre-amp out (or buffer) and the poweramps.
Of course the preamp/buffer must be able to handle this load.
It`s correct, there`re more possibilies with active crossovers but IMO that`s a feature not a disadvantage.
The "hand full" of right alignments applies to passive crossovers as well and be it active or passive, in both cases the possibilities are just to numerous to get it done in one stroke.
To me it wouldn`t make sense to rule out the potentially superior technology just to cut down the number of choices.
Yes guys, i openned this thread with many doubts, and i thank you all, because your
contributions are very near to give solutions to the main problem....how adjust flat having passive filters, without notch points, without double reeinforcement points.....also the problem with active.
Well, active is even worst to create those bandwidthes...i tried with passive, resulted great, but this is a more passionated feeling than a real great result, as i had peaks and valleys.
I tried blending, part of signal was passing from crossover input to output, giving me some sample of "equalized" sound .... brougth benefits, but did not satisfied me entirelly, lefting the passion out of that sittuation, the results obtained could be considered better than normal amplifiers with full range speakers, but could not be considered flat anyway.
The intention is to shorten the bandwidth to each amplifier, and each speaker, to turn easier to drive them....and not a gênius idea, thank you, the guy that accepted that possibility related me....no way to be gênius....my life shown me that i am not!... i am going to another marriage...just changing problems, as they will always exist....not even clever, to change an already known problem to another unknown problem.
Panasonic is doing this bi amplification for many years, using active filters....one cutting 100 hertz, to subwoofer, and other starting above that frequency...may have some valley between them not to increase 100 hertz, having two amplifiers driving this same frequency.
My intention is to avoid the local acoustics...the environment acoustics, adjusting each amplifier, or each speaker drive volume individually, this manual adjustment will be the "the real fun" to audiophiles...hehe
As we can have absortions somewhere....and some acoustic aid realted other places, as you observe Eva used a wall corner...this produces a much bigger bass..... a horn is created...enormous horn to bass there....so....in this case, the action is to reduce the frequencies under 100 hertz do avoid disconfort, if, because of your room, or because of your decision, the sub woofer was installed in some wall corner....this is an example only.
Panasonic obtained nice results that everyone can evaluate in normal audio stores, with that bi-amp....... so, it is logical to believe that multi-amp may be even better...or worst, because the reeinforcement point, valleys or notch points.
I, personally do not apreciate 200 to 250 hertz and 400 to 500 hertz...those frequencies, attenuated or notched makes me very happy....i really do not apreciate them....the realism it can produce to some instruments, are annoying to my person....but i am not a normal person...i hate strong french perfums...i prefer natural skin perfum.
The idea, and this is good to repeat, to remember, is that we may have many amplifiers already made, and each one of them with their own characteristics...one is wonderfull for bass, other wonderfull for trebles....so, it is interesting to use their capacities, and to put them to work, in the place of collecting dust.
Also, the secondary main idea, is that you may produce a nice sound, as having so many amplifiers, as you will not drive them hard, and this will produce lower distortions.
The only enormous disadvantage, is the wiring travelling, in special if the guy believe in those enormous monster cables.....well....in this moment a big problem will appear.......i think solution is very hard in this case..... the idea is to travel the thinner wires the way you can, in accordance with your wife, to avoid noises during musical audiotion (hehe)...accept the loss using lower impedance drivers to compensate those losses because of increase series resistance, separate wires to avoid capacitance, and have power reserve from your amplifiers units.
In real audition, will be difficult to have more than 2 watts in some tweeter that is working with an amplifier that is using an active crossover.
If you cut all frequencies under 8 kilohertz, the power present in those frequencies are naturally small in amplitude...so, you will have a big power reserve, even to drive not efficient speakers, to drive cheap speakers, inside sealed wooden enclosures (MDF is easy to cut and glue), just to avoid the phase cancelation... in the place of enclosure, you can also use only a front panel,a little bigger to avoid phase cancelation.
Some tweeters,m separated from midranges, forming a vertical column in your rigth and left, front wall corners can be used if you prefer some simple connection, using your house as speaker...of a front panel, creating a virtual triangular long speaker..using your walls and a single front panel painted in the same wall colour...this is, if you prefer some simple connection..... but remember that you have also up side corners...near the ceiling, that can be used, and thin cables can run there and be painted in the wall colour.
Try some passive filter and bi amplification with your stereo....just install some capacitors forming the greek letter "P"...the 3,14....
to filter high frequencies...send them to ground with 2k2 resistors and some 224 capacitors.....the other channel, try some series capacitors to block bass.....do this and perceive how interesting is the result in you own system...in your own stereo...and observe that this is not the best possible result, you may have some crossover inside your speakers, of course a problem creator, needed to linearise, but a problem creator, of course.
Also those snubbers that Carlos Fm told are usefull, as if you do not use, the treble is mufled...i was thinking that those snubber are not needed...but i was wrong, those things really works!
Never believe in our opinions, or friends ideas....more adequated, more happy is to feel by yourself, diy, try those things, the snubber serves as example...we have always something to lear, and it is impossible to learn without doing...we need the real experience, our feelings, our perception must work together our rationality...the real experience is definitive.
regards,
Carlos
contributions are very near to give solutions to the main problem....how adjust flat having passive filters, without notch points, without double reeinforcement points.....also the problem with active.
Well, active is even worst to create those bandwidthes...i tried with passive, resulted great, but this is a more passionated feeling than a real great result, as i had peaks and valleys.
I tried blending, part of signal was passing from crossover input to output, giving me some sample of "equalized" sound .... brougth benefits, but did not satisfied me entirelly, lefting the passion out of that sittuation, the results obtained could be considered better than normal amplifiers with full range speakers, but could not be considered flat anyway.
The intention is to shorten the bandwidth to each amplifier, and each speaker, to turn easier to drive them....and not a gênius idea, thank you, the guy that accepted that possibility related me....no way to be gênius....my life shown me that i am not!... i am going to another marriage...just changing problems, as they will always exist....not even clever, to change an already known problem to another unknown problem.
Panasonic is doing this bi amplification for many years, using active filters....one cutting 100 hertz, to subwoofer, and other starting above that frequency...may have some valley between them not to increase 100 hertz, having two amplifiers driving this same frequency.
My intention is to avoid the local acoustics...the environment acoustics, adjusting each amplifier, or each speaker drive volume individually, this manual adjustment will be the "the real fun" to audiophiles...hehe
As we can have absortions somewhere....and some acoustic aid realted other places, as you observe Eva used a wall corner...this produces a much bigger bass..... a horn is created...enormous horn to bass there....so....in this case, the action is to reduce the frequencies under 100 hertz do avoid disconfort, if, because of your room, or because of your decision, the sub woofer was installed in some wall corner....this is an example only.
Panasonic obtained nice results that everyone can evaluate in normal audio stores, with that bi-amp....... so, it is logical to believe that multi-amp may be even better...or worst, because the reeinforcement point, valleys or notch points.
I, personally do not apreciate 200 to 250 hertz and 400 to 500 hertz...those frequencies, attenuated or notched makes me very happy....i really do not apreciate them....the realism it can produce to some instruments, are annoying to my person....but i am not a normal person...i hate strong french perfums...i prefer natural skin perfum.
The idea, and this is good to repeat, to remember, is that we may have many amplifiers already made, and each one of them with their own characteristics...one is wonderfull for bass, other wonderfull for trebles....so, it is interesting to use their capacities, and to put them to work, in the place of collecting dust.
Also, the secondary main idea, is that you may produce a nice sound, as having so many amplifiers, as you will not drive them hard, and this will produce lower distortions.
The only enormous disadvantage, is the wiring travelling, in special if the guy believe in those enormous monster cables.....well....in this moment a big problem will appear.......i think solution is very hard in this case..... the idea is to travel the thinner wires the way you can, in accordance with your wife, to avoid noises during musical audiotion (hehe)...accept the loss using lower impedance drivers to compensate those losses because of increase series resistance, separate wires to avoid capacitance, and have power reserve from your amplifiers units.
In real audition, will be difficult to have more than 2 watts in some tweeter that is working with an amplifier that is using an active crossover.
If you cut all frequencies under 8 kilohertz, the power present in those frequencies are naturally small in amplitude...so, you will have a big power reserve, even to drive not efficient speakers, to drive cheap speakers, inside sealed wooden enclosures (MDF is easy to cut and glue), just to avoid the phase cancelation... in the place of enclosure, you can also use only a front panel,a little bigger to avoid phase cancelation.
Some tweeters,m separated from midranges, forming a vertical column in your rigth and left, front wall corners can be used if you prefer some simple connection, using your house as speaker...of a front panel, creating a virtual triangular long speaker..using your walls and a single front panel painted in the same wall colour...this is, if you prefer some simple connection..... but remember that you have also up side corners...near the ceiling, that can be used, and thin cables can run there and be painted in the wall colour.
Try some passive filter and bi amplification with your stereo....just install some capacitors forming the greek letter "P"...the 3,14....
to filter high frequencies...send them to ground with 2k2 resistors and some 224 capacitors.....the other channel, try some series capacitors to block bass.....do this and perceive how interesting is the result in you own system...in your own stereo...and observe that this is not the best possible result, you may have some crossover inside your speakers, of course a problem creator, needed to linearise, but a problem creator, of course.
Also those snubbers that Carlos Fm told are usefull, as if you do not use, the treble is mufled...i was thinking that those snubber are not needed...but i was wrong, those things really works!
Never believe in our opinions, or friends ideas....more adequated, more happy is to feel by yourself, diy, try those things, the snubber serves as example...we have always something to lear, and it is impossible to learn without doing...we need the real experience, our feelings, our perception must work together our rationality...the real experience is definitive.
regards,
Carlos
carlos
interesting post
honestly hadn't though about using the amps that way
"cutting input frequencies"
amplifying only the frequency range you want.
will try it.
but need the other amp finished first.
only need 2 amps ( 2 way speakers)
Question
How will the preamp handle driving 2 to 3 amps?
Could affect Zout, Zin
didn't like the idea of opamps btween preamp and amp.
alan
interesting post
honestly hadn't though about using the amps that way
"cutting input frequencies"
amplifying only the frequency range you want.
will try it.
but need the other amp finished first.
only need 2 amps ( 2 way speakers)
Question
How will the preamp handle driving 2 to 3 amps?
Could affect Zout, Zin
didn't like the idea of opamps btween preamp and amp.
alan
Looks like someone else has my mids too!
I biamp at 150hz and 1.5Khz, my HF horns (EV HP640) are mechanically time aligned with my mid horns.
An externally hosted image should be here but it was not working when we last tested it.
I biamp at 150hz and 1.5Khz, my HF horns (EV HP640) are mechanically time aligned with my mid horns.
Those amplifier will load the active filters outputs, that normally can be made to
low impedance...using a single class A stage....or the op amp can hold around 100 ohms
The amplifiers will represent normal impedance...as you will have one active circuit to each channel.
Using passive, i cannot tell you.... we really need some engineer to tell us...Help EVA!
Thank you....yes, i think the idea is nice, and i heard the result and i think this is a promisse of better quality, if someone enter to teach us hold to use those op amps to cut hi and low frequencies to some band pass.
Wonderfull DJK....very nice conditions you have, to listen good sound.
regards,
Carlos
low impedance...using a single class A stage....or the op amp can hold around 100 ohms
The amplifiers will represent normal impedance...as you will have one active circuit to each channel.
Using passive, i cannot tell you.... we really need some engineer to tell us...Help EVA!
Thank you....yes, i think the idea is nice, and i heard the result and i think this is a promisse of better quality, if someone enter to teach us hold to use those op amps to cut hi and low frequencies to some band pass.
Wonderfull DJK....very nice conditions you have, to listen good sound.
regards,
Carlos
Eva said:
Hola Eva,
It's exactly the exotic drive units that demand complex crossovers, either active or passive.
Fancy and $$$ metal cone woofers with high (10db+) breakup modes are the flavour of the day.
Actually, any woofer that demands anything higher than 1st order or (the maximum I would consider) 2nd order Bessel is NO GOOD for me.
But that's my way of thinking, and it is also my experience that simpler crossovers (active or passive) always sound better, less group delay.
You just have to choose the drive units with great care.
Btw regarding your comments about open baffles and amps, I couldn't agree more with you.
Saludos
cocolino said:
I know, and I would only consider doing that inside each power amp, right where it would work better.
But I don't need it, with the speakers I use, and only someone that has listenen to them can tell you how neutral (and detailed) they sound.
The drivers were made to work that way, no crossover on the woofer (it's actually almost a fullrange), first order on the tweeter.
Don't try to make this with other drivers, it won't sound good. Choosing a driver for this purpose can be a search of a lifetime.
I would kill the sound of the speaker if I filtered the woofer, that magical (but at the same time very neutral) midband would be gone.
You know what, the cap on the tweeter is 1.5uF polyprop, with a parallel 47R resistor across the tweeter.
Weird, huh?
It's crossed quite high...How can that sound decent?
The secret is on the drivers, and you must listen to the speaker to believe that it actually works.
destroyer X:
That horn is not so corner loaded as it appears, because the mouth is almost 1 meter away from the corner and it's crossed over at 270Hz to a folded bass horn that is placed behind and is not shown, so it's plain midrange. The bass horn is the one corner loaded, but it looks too ugly to be shown here (parameters: 15" driver, 60L reflex rear chamber tuned to 36hz, small front chamber >5L, 320cm^2 to 3200cm^2 exponential expansion with 140cm length and two 90 degree folds).
Concerning frequencies between 250Hz and 500Hz, these are actually sweet, but direct radiation stuff usually ruins them due to enclosure modes and room interactions (it's easy to figure out why since the corresponding half wavelengths are between 70 and 35 cm and are usually radiated in *every* direction creating a true acoustic mess).
carlosfm:
Then I should be very lucky because, altough I've tried very hard, I've not been capable of hear group delay, at least not in the amounts introduced by my 4th order circuits. However, I enjoy the acoustical benefits of the alignment provided by such crossovers and phase shifters.
That horn is not so corner loaded as it appears, because the mouth is almost 1 meter away from the corner and it's crossed over at 270Hz to a folded bass horn that is placed behind and is not shown, so it's plain midrange. The bass horn is the one corner loaded, but it looks too ugly to be shown here (parameters: 15" driver, 60L reflex rear chamber tuned to 36hz, small front chamber >5L, 320cm^2 to 3200cm^2 exponential expansion with 140cm length and two 90 degree folds).
Concerning frequencies between 250Hz and 500Hz, these are actually sweet, but direct radiation stuff usually ruins them due to enclosure modes and room interactions (it's easy to figure out why since the corresponding half wavelengths are between 70 and 35 cm and are usually radiated in *every* direction creating a true acoustic mess).
carlosfm:
Then I should be very lucky because, altough I've tried very hard, I've not been capable of hear group delay, at least not in the amounts introduced by my 4th order circuits. However, I enjoy the acoustical benefits of the alignment provided by such crossovers and phase shifters.
For me it sounds "faster" when it's aligned, otherwise the waveforms coming from the woofer and the midrange (or the midrange and the tweeter) cancel out themselves and so it sounds, cancelled, deprived of transient information. This gets worse as the order of the crossover is reduced because the overlapping region is wider.
Actually there are several ways of approaching speaker design (or system building, for that matter), and I don't think it's correct to say that there's only one or the way for getting good results.
What matters is the final sonic result, and if you like it.
I have my priorities in audio, which are being able to hear as faithfully as possible the sound of real, unamplified instruments.
Others may prefer a different type of sound, and search for a live concert type of presentation, being blown away in front of a pair of PA speakers.
Everything is valid, as long as you like it.
What matters is the final sonic result, and if you like it.
I have my priorities in audio, which are being able to hear as faithfully as possible the sound of real, unamplified instruments.
Others may prefer a different type of sound, and search for a live concert type of presentation, being blown away in front of a pair of PA speakers.
Everything is valid, as long as you like it.
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