I want to help people obtain better sound quality and thus want to keep this thread as factual as possible, so I'll try to start with this statement:
'Any passive multi-way you make I can make vastly superior, actively.'
I say this due to science and actually measuring speakers and analysing the datasheets. Science can and does produce great sound quality, a lot think it's magic because they are stupid and can't understand the parameters in their experiments. What I want to talk about is just one very simple aspect of drivers and their frequency response. One fact is the higher order you go passively the higher it costs and the higher amount of distortion it will introduce. Which is very audible.
You will see it's very hard to get two drivers (woofer and tweeter) to match in the middle. Generally a good 5" driver will not work very well above 4kHz - generally! - and a tweeter below 2kHz. Imagine a 12dB typical filter for this design crossed at 3kHz, at 6kHz the driver will only be 12dB down! The break up will be extremely audible! The tweeter will really be struggling because at just 1.5kHz it will also be just 12dB down, this is very worrying especially at high volume. In my actives designs it's extremely easy to use 8th order filters and thus the drivers are used in much better regions creating an amazingly clear sound - I love it.
For this simple fact of active filters are way and beyond cave man passive filters actives will always win.
By all means an active system can sound terrible if it is not designed correctly.
I really want people to enjoy their music, I hope this will encourage people to look into actives at least.
'Any passive multi-way you make I can make vastly superior, actively.'
I say this due to science and actually measuring speakers and analysing the datasheets. Science can and does produce great sound quality, a lot think it's magic because they are stupid and can't understand the parameters in their experiments. What I want to talk about is just one very simple aspect of drivers and their frequency response. One fact is the higher order you go passively the higher it costs and the higher amount of distortion it will introduce. Which is very audible.
You will see it's very hard to get two drivers (woofer and tweeter) to match in the middle. Generally a good 5" driver will not work very well above 4kHz - generally! - and a tweeter below 2kHz. Imagine a 12dB typical filter for this design crossed at 3kHz, at 6kHz the driver will only be 12dB down! The break up will be extremely audible! The tweeter will really be struggling because at just 1.5kHz it will also be just 12dB down, this is very worrying especially at high volume. In my actives designs it's extremely easy to use 8th order filters and thus the drivers are used in much better regions creating an amazingly clear sound - I love it.
For this simple fact of active filters are way and beyond cave man passive filters actives will always win.
By all means an active system can sound terrible if it is not designed correctly.
I really want people to enjoy their music, I hope this will encourage people to look into actives at least.
If you use 8th order filters then take a look at the off axis response & time domain response and then you might realize it's not that beautiful after all.
Phase is double that of 4th order - not looked badly upon. Pre filter yes the phase is dramatic but post? Who cares it's attenuated.
The audibility of driver break up is far more dramatic than the phase issue at the crossover point.
The audibility of driver break up is far more dramatic than the phase issue at the crossover point.
In the crossover region: sure you can get it nice on axis as the drivers sum, but does it look as nice off axis?
ADDITION: Also, if one wants to use a driver higher up into the breakup region then it's as simple as just choosing a driver that behaves gracefully there. One doesn't have to hide it with very steep filters.
Last edited:
Umm personally I don't really care, I sit in front of my speakers?
I understand if people have their speakers all over the room however I don't think you'll be benefiting largely in sound quality if that were the case.
I understand if people have their speakers all over the room however I don't think you'll be benefiting largely in sound quality if that were the case.
Is your room an anechoic chamber? If not then yeah, you should care about the off axis response.
Because the off axis response will bounce around in the room and influence the sound of course. It's not random chance that most better speaker builders are transitioning into building speakers that have constant directivity = good and consistent off axis response.
Then, in theory, highly directional speakers would be better?
If you were to have a perfect 180 degree dispersion in the full FR it wouldn't matter in the slightest. You prove your own point in anything less than an anechoic chamber the on axis response would be uncontrollable with off axis reflections. This would be impossible to compensate for due to the variety in listening setups.
So are you saying by 'better' that it sounds better going active? It seems you are because you conclude with saying you want people to enjoy their music more. In which case I'd argue that perhaps actives do sound better but that isn't for the reasons you're suggesting in assigning the presumably pejorative epithet 'cave man' to passive filters.
In my experience any active speaker with an active crossover will sound better still when the active crossover is changed for a passive one. This hints at the real reason why active speakers sound better - not because passive XOs sound bad but because amps in active speakers are performing better when given a narrower band of signals to amplify.
In my experience any active speaker with an active crossover will sound better still when the active crossover is changed for a passive one. This hints at the real reason why active speakers sound better - not because passive XOs sound bad but because amps in active speakers are performing better when given a narrower band of signals to amplify.
In theory you can have any dispersion pattern you want, but the ideal is that it is constant over the whole frequency range.
So one of them is highly directional yes, that's what Earl Geddes are doing. Another way is to have dipoles like Linkwitz is doing, but in essence it's the same thing as the overall pattern is frequency independant. Omni is another one you can have, so you don't have to try to reduce directivity but rather just keep it constant.
A big advantage with this kind of speaker is that it as the off axis response / reflections have the same content (though possibly attenuated) as the on axis response they aren't really a problem.
Yes well we will never conclude on what sounds 'better', but I mean 'better' in the sense of higher clarity, less listening fatigue, better sound stage etc.
I don't understand why having no components in-between the amp and speaker can sound worse than with inefficient, and often non linear components in the way.
I have 140W just for the woofer in my actives and 70W for the tweeter. This means they do not clip at low levels which a typical low power amp used with passive will do all day long.
Your active filter is made up of inefficient and non-linear components. Getting those out of the way for less non-linear components improves the sound, IME.
I'm not talking about putting a speaker level passive XO into an active speaker, rather a line level passive XO replacing the traditional opamp-based active filter.
I'm not talking about putting a speaker level passive XO into an active speaker, rather a line level passive XO replacing the traditional opamp-based active filter.
I see, well you won't be able to tell the difference between a good active crossover with an op amp and nothing (if that could be possible). The THD is just far to low.
I'm talking about passive crossovers after the amp.
You said that passive XOs were 'cave man' - I dispute that claim. THD isn't a good measure of how something sounds.
I'm not arguing for passive crossovers after the amps, that is indeed 'cave man' 😀
I'm not arguing for passive crossovers after the amps, that is indeed 'cave man' 😀
Once THD, or any distortion for that matter is below a certain threshold, it ceases to be meaningful IMO, the distortion products produced by even the most well engineered drivers is going to be far more than anything introduced by electronics.
I'll also admit my personal opinion, that there's more to how something sounds than a spec sheet, there's just too many things at play besides "this one has 0.1% distortion so it's automatically better than this one with 0.15%" You should all probably come to a consensus about which type of active filtering you're talking about, I.E A/D convert -> X/O -> D/A convert -> output stage or plain analog components.
You've started your thread with an oxymoron:
'I want... to keep this thread as factual as possible'
'Any passive multiway you make I can make vastly superior, actively.'
Likewise, the sweeping remarks, sans any form of proper qualification, that 'active... will always win', 'cave-man passive' etc.
Those are not factual statements. They are your opinion, and require vast amounts of qualification / noting of caveats. LR8 for instance. LR8 is not a panacea. 8th order can certainly be a useful option in some situations, but it is no more or less valid than anything else, and has its problems, like all other XO slopes. Got yourself a couple of drivers with low distortion, wide, smooth BW & have only modest requirements for power-handling? LR2 may well prove more effective for reasons that you are presumably aware of.
Most people here are well aware that active loudspeakers can have much to offer, but they are no more of a panacea than 8th order filters, nor will they automatically outperform a speaker with a passive filter simply because they are active. They may. They may not. Depends on a host of factors.
As for this:
Insulting / patronising comments we can do without thank you.
As you see it, what are the advantages and disadvantages of 8th order filters (and of what type)? Why do you think expensive professional speakers rarely use such filters?
- Status
- Not open for further replies.