Hi,
I am "considering" building active crossovers for a spare pair of NS1000M speakers. Before getting further than "considering", I have tried to find out the benefits of going "active".
Generally, it seems to be improved clarity resulting from the separation of the mid/high parts of the system from the bass sections when bass overload is happening. Also, improved power outputs overall. Well, what if you don't listen at such high-levels? Where are the benefits, if any, coming from?
If the benefits are seen to be very significant then surely most hi-end speakers should be active? In fact, it does not seem that many are.
I guess what I am asking for is some clarification... where are the benefits coming from... especially at medium listening levels? Are there any measurements made on active vs. passive systems that allow some objectivity in appreciating the benefits. Going active adds considerably to the cost and complexity of a system and I would appreciate some kind of roadmap on this. Confusingly, I have even read that on JBL 4345 biased passive crossovers are preferred to active! Help!
I am "considering" building active crossovers for a spare pair of NS1000M speakers. Before getting further than "considering", I have tried to find out the benefits of going "active".
Generally, it seems to be improved clarity resulting from the separation of the mid/high parts of the system from the bass sections when bass overload is happening. Also, improved power outputs overall. Well, what if you don't listen at such high-levels? Where are the benefits, if any, coming from?
If the benefits are seen to be very significant then surely most hi-end speakers should be active? In fact, it does not seem that many are.
I guess what I am asking for is some clarification... where are the benefits coming from... especially at medium listening levels? Are there any measurements made on active vs. passive systems that allow some objectivity in appreciating the benefits. Going active adds considerably to the cost and complexity of a system and I would appreciate some kind of roadmap on this. Confusingly, I have even read that on JBL 4345 biased passive crossovers are preferred to active! Help!
First question, have you looked at the many many threads on this topic over the last 10 years that have covered all your questions before descending into inevitable chaos.
Reason for few active speakers in high-end is twofold
1. High-enders like to mix and match. Removing amplifier choice upsets them
2. Dealer make most profit on boutique cables. active speakers oft removes that sale.
Reason for few active speakers in high-end is twofold
1. High-enders like to mix and match. Removing amplifier choice upsets them
2. Dealer make most profit on boutique cables. active speakers oft removes that sale.
Active
I tried to look into these threads. Those I found were mostly just opinion and I know you are aware, this can be pretty misleading. If you can point me to some useful none dogmatic threads I should be very grateful.
I tried to look into these threads. Those I found were mostly just opinion and I know you are aware, this can be pretty misleading. If you can point me to some useful none dogmatic threads I should be very grateful.
Those are a rare beast here!
The big challenge is that with active crossovers your are on a paradigm boundary. Speaker designers think in acoustic slopes. Electron herders think in electrical slopes and marrying the two views is harder than might first seem.
Yamaha-NS1000 is a good starting point as it goes into what is wrong with the stock cross-over and shows you what you can adjust. After reading that you can think about how you would implement those slopes in (say) miniDSP. The analysis done is what a lot of those coming from the electrical side miss and certainly what many of the active crossover textbooks miss.
Thanks
Thanks.. I shall be starting a long read pretty soon now... still no further
on defining why active is generally better.... ignoring the dogmatic JBL group for now
Thanks.. I shall be starting a long read pretty soon now... still no further
on defining why active is generally better.... ignoring the dogmatic JBL group for now
8 Advantages of Active Crossovers Douglas Self | Audio Undone
Doug Self's view on why, which you may or may not agree with. And a video from burning amp https://www.youtube.com/watch?v=f_zkE_42BV4
You can do things easily in active that are very hard to do passive. Time alignment, lots of eq etc. You can also experiment with different methods such as the Harsch method or the Thiele method.
Doug Self's view on why, which you may or may not agree with. And a video from burning amp https://www.youtube.com/watch?v=f_zkE_42BV4
You can do things easily in active that are very hard to do passive. Time alignment, lots of eq etc. You can also experiment with different methods such as the Harsch method or the Thiele method.
Self
The Self presentation which I have just started watching is very informative. As I am currently building the Huff-Self preamp, I suspect that Self's view will fit into what I am doing quite well. Thanks for that link.
BTW, this is the first time that I have actually seen Self. Nothing at all like I imagined.
The Self presentation which I have just started watching is very informative. As I am currently building the Huff-Self preamp, I suspect that Self's view will fit into what I am doing quite well. Thanks for that link.
BTW, this is the first time that I have actually seen Self. Nothing at all like I imagined.
You won't find much information on 'why active is better' for the simple reason that it really isn't that simple. Active crossovers are not uniformly and invariably 'better' than passive, or visa versa. They're just different, and they each come with their own balances of advantages / disadvantages (or trade-offs if you will). The reason most of the threads on this particular subject descend into chaos is because a number of people are for their own reasons obsessively partisan for one or the other, and refuse point-blank to accept that other people may have different requirements to themselves, which they are entitled to have without being pontificated at.
Active crossovers can reduce losses, and if done via digital manipulation can incorporate additive EQ as well as subtractive (passive filters only subtract, not add). 'Can' is the operative word there, because other losses, for e.g. connection losses, do exist, and in higher efficiency systems this can become an issue (note caveat). Active XOs may therefore have just as many opportunities for such losses, as there are still a number of connections. As noted though, this is context dependent. Active filters can also be somewhat more flexible and allow quicker, easier and possibly cheaper fine-tuning or even larger scale adjustments than can be done with passive filters, where you would be essentially soldering / clip-leading alternative components in. They are less susceptible to vibration -passive filters internal to a speaker box, notably the caps, can suffer from microphonic issues as they are subject to the varying vibration and changes in air pressure. There are potential downsides too however. You need a greater number of amplifiers / cannot use an integrated amp, so cost and space may become a problem. It's still a set of components in the signal chain, or digital manipulation of the original signal, so they are subject to the potential issues that by definition entails, either with errors, noise, losses etc. creeping in. The ease of manipulation can also be problematic for people new to XO design, who may end up flailing around in the dark thinking they've got a panacea, and ending up with mediocre results. They don't liberate the user from needing to design a crossover -you still need to know how to manipulate the response. And you can end up with a bunch of extra speaker wires, which may be an aesthetic or practical issue.
Passive filters by contrast allow a simpler system (a single stereo amplifier), do not involve either digital manipulation (which if you want an all-analogue system is a bit of an issue
) or a bunch of op-amps / similar in the signal chain, are usually more compact, and mean you don't require multiple additional speaker wires hanging about if you don't want them (which can be an issue for domestic harmony. Or, if you don't happen to like seeing a large number of wires yourself). Downsides are potential higher cost, especially if you buy into fancy components, they're ultimately less flexible in terms of what you can do (although that does depend on the features of the active filter you purchase or buy), they are by definition lossy, and may have more components / connections in the signal path (see caveat above -this varies with system specifics).
Those are a few of the basic for / against arguments for active and passive filters. There are plenty of others of course. Which will ultimately be more suitable depends very much on what you want to do -the main piece of advice being don't let anybody else tell you 'what you want' (i.e. what they want). You're the one calling the shots, not somebody else.
Rgds
Scott
Active crossovers can reduce losses, and if done via digital manipulation can incorporate additive EQ as well as subtractive (passive filters only subtract, not add). 'Can' is the operative word there, because other losses, for e.g. connection losses, do exist, and in higher efficiency systems this can become an issue (note caveat). Active XOs may therefore have just as many opportunities for such losses, as there are still a number of connections. As noted though, this is context dependent. Active filters can also be somewhat more flexible and allow quicker, easier and possibly cheaper fine-tuning or even larger scale adjustments than can be done with passive filters, where you would be essentially soldering / clip-leading alternative components in. They are less susceptible to vibration -passive filters internal to a speaker box, notably the caps, can suffer from microphonic issues as they are subject to the varying vibration and changes in air pressure. There are potential downsides too however. You need a greater number of amplifiers / cannot use an integrated amp, so cost and space may become a problem. It's still a set of components in the signal chain, or digital manipulation of the original signal, so they are subject to the potential issues that by definition entails, either with errors, noise, losses etc. creeping in. The ease of manipulation can also be problematic for people new to XO design, who may end up flailing around in the dark thinking they've got a panacea, and ending up with mediocre results. They don't liberate the user from needing to design a crossover -you still need to know how to manipulate the response. And you can end up with a bunch of extra speaker wires, which may be an aesthetic or practical issue.
Passive filters by contrast allow a simpler system (a single stereo amplifier), do not involve either digital manipulation (which if you want an all-analogue system is a bit of an issue
) or a bunch of op-amps / similar in the signal chain, are usually more compact, and mean you don't require multiple additional speaker wires hanging about if you don't want them (which can be an issue for domestic harmony. Or, if you don't happen to like seeing a large number of wires yourself). Downsides are potential higher cost, especially if you buy into fancy components, they're ultimately less flexible in terms of what you can do (although that does depend on the features of the active filter you purchase or buy), they are by definition lossy, and may have more components / connections in the signal path (see caveat above -this varies with system specifics). Those are a few of the basic for / against arguments for active and passive filters. There are plenty of others of course. Which will ultimately be more suitable depends very much on what you want to do -the main piece of advice being don't let anybody else tell you 'what you want' (i.e. what they want). You're the one calling the shots, not somebody else.
Rgds
Scott
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Just watched the presentation... very useful. Thanks for the reference. BTW, I imagined him smoother. I guess I have seen too many marketing guys and very (very) few EE presentations.
To backup Scott. This is a very interested Zaph design Zaph|Audio . I cannot for the life of me see anyway that doing this crossover actively would give an advantage commensurate with the effort. BUT its a rare case that first order electrical slopes drop in quite that nicely.
The fact is that you can't throw an active filter at a speaker and expect to get good results.
It takes as much work, if not more, to get a decent sounding active system as a passive. In addition, most drivers are designed with a fairly typical usage in mind and thus it is quite easy to work with their natural frequency and impedance characteristics as long as those characteristics are well-balanced and predictable.
The arguments for active are in significantly reduced power loss and enhanced electrical damping, plus the versatility of being able to get a workable response at will (seemingly). Also the freedom to adjust each output to work with variations in real-world speakers. And all of this is true as well.
In my experience it takes a lot of work to get an active right, and it isn't possible to do unless the drivers being used go together well in the first place. If you have good drivers and invest time in the project, you can get great results from either.
I have to use EQ, BSC as well as the actual XO slopes, plus I have a 3-way system (2.1, actually with five amplifiers) so it becomes complex pretty quickly. In a passive system I could probably achieve the woofer filter with a single inductor and capacitor, which would automatically handle the EQ and BSC if done right. The result is a simpler system with less components (and usually, much more gentle electrical slopes).
To mirror your note on JBL, Dynaudio also seem to recommend their passive models with large external amplifiers over their active ones (or that's what the dealers like to tell you, because their margins on the passive models *may* be larger). I think one of the reasons pointed out was that the budget limit also places a limit on what kind of amplifier can be used in the active monitors, which for a DIY project would not really be an issue.
It takes as much work, if not more, to get a decent sounding active system as a passive. In addition, most drivers are designed with a fairly typical usage in mind and thus it is quite easy to work with their natural frequency and impedance characteristics as long as those characteristics are well-balanced and predictable.
The arguments for active are in significantly reduced power loss and enhanced electrical damping, plus the versatility of being able to get a workable response at will (seemingly). Also the freedom to adjust each output to work with variations in real-world speakers. And all of this is true as well.
In my experience it takes a lot of work to get an active right, and it isn't possible to do unless the drivers being used go together well in the first place. If you have good drivers and invest time in the project, you can get great results from either.
I have to use EQ, BSC as well as the actual XO slopes, plus I have a 3-way system (2.1, actually with five amplifiers) so it becomes complex pretty quickly. In a passive system I could probably achieve the woofer filter with a single inductor and capacitor, which would automatically handle the EQ and BSC if done right. The result is a simpler system with less components (and usually, much more gentle electrical slopes).
To mirror your note on JBL, Dynaudio also seem to recommend their passive models with large external amplifiers over their active ones (or that's what the dealers like to tell you, because their margins on the passive models *may* be larger). I think one of the reasons pointed out was that the budget limit also places a limit on what kind of amplifier can be used in the active monitors, which for a DIY project would not really be an issue.
Hello George,
here is a link to an article you should read about (supposed and objective) benefits of active crossover/multiamp set up:
BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1
BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 2
As Scott said there is always trade off to every design choice you make, and what is good for you may not be for others.
For my own taste: active dsp filtering and multi amp is the way to go, but it has some annoying issues versus a passive filter design.
One of this already mentionned by Scott is the need to use an other analog to digital stage in the signal path when you use analog source (TT).
An other one is latency (depending on type of dsp filtering you use if the solution you use give you choice between IIR and FIR (the latter induce possible large amount of latency if you need to cross 'low' -sub 500hz).
The last one be in the volume control, as once you have multiple DA and multiple amps accurate analog volume control start to be problematic unless you use discrete stepped attenuators. Most users use digital attenuation at the output of the player (or between player and output DAC) restricting the resolution of DACs (sometimes making 24bits converters effectively working as 16bits or sometime lesser resolutions which in any case won't add benefits in sound quality).
And you should not forget to think about other trade off about the cost/size/ relative difficulty to operate the system (you can't just flick a switch to play music: you'll have to follow an order to switch on AND off your system or you have potential dramatic failure possible, particularly if you're not protecting your HF driver from dc thump... so if your girlfriend/child have to operate the system you must think of it).
That is a lot of drawbacks but to my taste (i repeat) this is worth the effort, especially if your source is mainly digital and you can use high quality DACs/hardware dsp/software.
here is a link to an article you should read about (supposed and objective) benefits of active crossover/multiamp set up:
BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1
BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 2
As Scott said there is always trade off to every design choice you make, and what is good for you may not be for others.
For my own taste: active dsp filtering and multi amp is the way to go, but it has some annoying issues versus a passive filter design.
One of this already mentionned by Scott is the need to use an other analog to digital stage in the signal path when you use analog source (TT).
An other one is latency (depending on type of dsp filtering you use if the solution you use give you choice between IIR and FIR (the latter induce possible large amount of latency if you need to cross 'low' -sub 500hz).
The last one be in the volume control, as once you have multiple DA and multiple amps accurate analog volume control start to be problematic unless you use discrete stepped attenuators. Most users use digital attenuation at the output of the player (or between player and output DAC) restricting the resolution of DACs (sometimes making 24bits converters effectively working as 16bits or sometime lesser resolutions which in any case won't add benefits in sound quality).
And you should not forget to think about other trade off about the cost/size/ relative difficulty to operate the system (you can't just flick a switch to play music: you'll have to follow an order to switch on AND off your system or you have potential dramatic failure possible, particularly if you're not protecting your HF driver from dc thump... so if your girlfriend/child have to operate the system you must think of it).
That is a lot of drawbacks but to my taste (i repeat) this is worth the effort, especially if your source is mainly digital and you can use high quality DACs/hardware dsp/software.
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Hi,
I am getting the feeling right now that a lot of the active filter benefits accrue to the designers of such filters. A DIYer purchasing such a filter will have a pretty busy time tuning it to the units that they have. Your point about complexity is well taken. Although my system has a single on / off button (via wireless remote on/off), should the sound not appear then the complexity of finding out why not is more than most domestic situations can handle. There is a lot to be said for simplicity....and I although I find active crossover concept attractive I am looking towards first updating the passive crossover and then reviewing the situation. To my knowledge there are only 2 active crossovers available for my NS1000M speaker and one of those is out of production... so not a great choice.
I am getting the feeling right now that a lot of the active filter benefits accrue to the designers of such filters. A DIYer purchasing such a filter will have a pretty busy time tuning it to the units that they have. Your point about complexity is well taken. Although my system has a single on / off button (via wireless remote on/off), should the sound not appear then the complexity of finding out why not is more than most domestic situations can handle. There is a lot to be said for simplicity....and I although I find active crossover concept attractive I am looking towards first updating the passive crossover and then reviewing the situation. To my knowledge there are only 2 active crossovers available for my NS1000M speaker and one of those is out of production... so not a great choice.
George,
as soon as you are playing (modifying) the filters in your loudspeakers you are 'tuning' them, active or passive and you can spend lot of time on it, either way (active/passive). You'll need tools too to know what you 're doing (calib measurement mic, software is a minimum and understand how to gain significant results too).
Updating passive can be a difficult task and not cheap one too. I don't want to scare you about that, but i started same way as you: bringing up to date the passive filter in my monitors.
It ended in 3 way dsp multi amp.
as soon as you are playing (modifying) the filters in your loudspeakers you are 'tuning' them, active or passive and you can spend lot of time on it, either way (active/passive). You'll need tools too to know what you 're doing (calib measurement mic, software is a minimum and understand how to gain significant results too).
Updating passive can be a difficult task and not cheap one too. I don't want to scare you about that, but i started same way as you: bringing up to date the passive filter in my monitors.
It ended in 3 way dsp multi amp.
Yes, but the thing is with the passives all I would do is replace old caps with new.. not redesign. With active it appears to be a longer job.
Here's a strategy... I upgrade my main pair of NS1000M with passive crossover improvements and in parallel start on the long trek of making active the other pair. I could even do a real A-B comparison. I think I have time for this.. my health is good and ears stil work
Here's a strategy... I upgrade my main pair of NS1000M with passive crossover improvements and in parallel start on the long trek of making active the other pair. I could even do a real A-B comparison. I think I have time for this.. my health is good and ears stil work
Yes indeed. I'll precise my thought: don't worth the hassle of going active if you are not 'upgrading' your filter from the stock passive one. You'll have benefits for sure (in my point of view) but not something that at the end is worth the money and efforts.
If you redesign the whole filter thing this is another story... But you'll spend time, money and have a much more 'complex' system to live with at the end. That's my experience on the subject, but as said before i am biased, results gained in my case outwheight cons largely: after 12 years with my speakers i discovered what they where really able to do.
But it 'll not make them my last pair of speakers.
Advantages:
- easy to get filters with a correct (linear) response and higher slopes
- less power needed to drive the speakers
- often cheaper, even the fact that they need a power supply doesn't make them expensive, since they're low on power consumption
- better documentation (I found passive crossovers to be a sort of "black magic" thing, there's no standard recipe since they're dependent on the characteristics of the system)
- can usually be ported to other systems (depending on the crossover points)
Advice:
- use quality components, they're not that expensive: plastic film caps and 1% resistors
- use op-amps, it's easier to work with them and understand the standard active filter topologies
- test the crossover frequencies digitally before implementing
- you can use chip amps for bookshelf/low power systems
- use tried and tested implementations (like the ESP-LR crossover)
- easy to get filters with a correct (linear) response and higher slopes
- less power needed to drive the speakers
- often cheaper, even the fact that they need a power supply doesn't make them expensive, since they're low on power consumption
- better documentation (I found passive crossovers to be a sort of "black magic" thing, there's no standard recipe since they're dependent on the characteristics of the system)
- can usually be ported to other systems (depending on the crossover points)
Advice:
- use quality components, they're not that expensive: plastic film caps and 1% resistors
- use op-amps, it's easier to work with them and understand the standard active filter topologies
- test the crossover frequencies digitally before implementing
- you can use chip amps for bookshelf/low power systems
- use tried and tested implementations (like the ESP-LR crossover)
Great discussion everyone! I've been out of the game for a while but getting back in, I am in the planning stages of actively XO'd 2channel system and am seriously considering the miniDSP 2x8 to control a 4-way set of towers I'm designing.
Any other good options I should be considering or any feedback on the miniDSP? Thanks!
Any other good options I should be considering or any feedback on the miniDSP? Thanks!
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