Speaker impedance is complex already without any added components. What is the big plus?
Direct drive with less impredictable behavior from the circuit between amp and driver iirc.
Let me search it, i think i already quoted Newell's plus about it on a message some years ago (... or search for the book to quote it!)
Let me search it, i think i already quoted Newell's plus about it on a message some years ago (... or search for the book to quote it!)
Points 7, 12, 13, 23 are answers to your question in my view.
The writing is a bit old now, before FIR era. The target are not domestic systems but it list most benefits of principle ( ESP ( Rodd Elliott's site) have almost same list in 'benefits of bi amplification').
I included his pov of benefits of passive.
Please notice this is not my pov even if i share most of it, my reference for 'best i heard' is a passive system ( but i choosen to use dsp/multiamp nevertheless).
From P. Newell 'Recording Studio Design', Focal Press, p514
1 Loudspeaker drive units of different sensitivities may be used in one system,
without the need for ‘lossy’ resistive networks or transformers. This can be
advantageous because drive units of sonic compatibility may be electrically
incompatible in passive systems.
2 Distortions due to overload in any one band are captive within that band,
and cannot affect any of the other drivers.
3 Occasional low frequency overloads do not pass into the high frequency
drivers, and instead of being objectionable, if slight, may be inaudible.
4 Amplifier power and distortion characteristics can be optimally matched
to the drive unit sensitivities and frequency ranges.
5 Driver protection, if required, can be precisely tailored to the needs of each
driver.
6 Complex frequency-response curves can easily be realised in the electronics,
to deliver flat (or as required) acoustic responses in front of the
loudspeakers. Driver irregularities can, except if too sharp, be easily regularised.
7 Complex load impedances are simplified, making amplifier performance
(and the whole system performance) more predictable.
8 System intermodulation distortion can be dramatically reduced.
9 Cable problems can be significantly reduced.
10 If mild low frequency clipping or limiting can be tolerated, much higher
SPLs can be generated from the same drive units (vis-à-vis their use in
passive systems) without subjective quality impairment.
11 Modelling of thermal time constants can be incorporated into the drive
amplifiers, helping to compensate for thermal compression by the drive
units, although they cannot eliminate its effects.
12 Low source impedances at the amplifier outputs can damp out-of-band
resonances in drive units, which otherwise would be uncontrolled due to
the passive crossover effectively buffering them away from the amplifier.
13 Drive units are essentially voltage-controlled, which means that when
coupled directly to a power amplifier (most of which act like voltage
sources) they can be more optimally driven than when impedances
are placed between the source and load, such as by passive crossover
components.
14 Direct connection of the amplifier and loudspeaker is a useful distortion
reducing system. It can eliminate the strange currents that can often flow
in complex passive crossovers.
15 Higher order filter slopes can easily be achieved without loss of system
efficiency.
16 Low frequency cabinet/driver alignments can be made possible which, by
passive means, would be more or less out of the question.
17 Drive unit production tolerances can easily be trimmed out.
18 Driver ageing drift can easily be trimmed out.
19 Subjectively, clarity and dynamic range are generally considered to be
better on active systems compared to their passive equivalents (i.e. same
boxes, same drive units).
20 Out of band filters can easily be accommodated, if required.
21 Amplifier design may be able to be simplified, sometimes to sonic benefit.
22 In passive loudspeakers used at high levels, voice-coil heating will change
the impedance of the drive units, which in turn will affect the crossover
termination. Crossover frequencies, as well as levels, may dynamically shift.
Actively crossed over loudspeakers are immune from this effect.
23 Problems of inductor siting, to minimise interaction with drive unit voice
coils at high current levels, are nullified.
24 Active systems have the potential for the relatively simple application of
motional feedback, which may come more into vogue as time passes.
Conversely, the list of benefits for the use of passive, high level crossovers
for large studio monitors would typically consist of:
1 Reduced cost? Not necessarily, because several limited bandwidth amplifiers
may be cheaper to produce than one large one capable of driving complex
loads. (The loudspeaker may be cheaper but the system more expensive).
2 Passive crossovers are less prone to being misadjusted by studio engineers.
True, but in a professional studio one ought to be able to expect a degree of
responsibility in the use of professional systems. However, passive systems
have a tendency to adjust themselves with age.
3 Simplicity? Not really, because very high quality passive, high-level crossovers
can be hellishly complicated to implement, not to mention the amplifiers
which are needed to drive them.
4 Self-containment of the loudspeaker system: but this is probably only
interesting for hi-fi enthusiasts who wish to use them with their favourite
amplifiers.
5 Ruggedness? No; because the electrolytic capacitors (necessary for the
large values) are notorious for ageing, and gradually changing their values.
The writing is a bit old now, before FIR era. The target are not domestic systems but it list most benefits of principle ( ESP ( Rodd Elliott's site) have almost same list in 'benefits of bi amplification').
I included his pov of benefits of passive.
Please notice this is not my pov even if i share most of it, my reference for 'best i heard' is a passive system ( but i choosen to use dsp/multiamp nevertheless).
From P. Newell 'Recording Studio Design', Focal Press, p514
1 Loudspeaker drive units of different sensitivities may be used in one system,
without the need for ‘lossy’ resistive networks or transformers. This can be
advantageous because drive units of sonic compatibility may be electrically
incompatible in passive systems.
2 Distortions due to overload in any one band are captive within that band,
and cannot affect any of the other drivers.
3 Occasional low frequency overloads do not pass into the high frequency
drivers, and instead of being objectionable, if slight, may be inaudible.
4 Amplifier power and distortion characteristics can be optimally matched
to the drive unit sensitivities and frequency ranges.
5 Driver protection, if required, can be precisely tailored to the needs of each
driver.
6 Complex frequency-response curves can easily be realised in the electronics,
to deliver flat (or as required) acoustic responses in front of the
loudspeakers. Driver irregularities can, except if too sharp, be easily regularised.
7 Complex load impedances are simplified, making amplifier performance
(and the whole system performance) more predictable.
8 System intermodulation distortion can be dramatically reduced.
9 Cable problems can be significantly reduced.
10 If mild low frequency clipping or limiting can be tolerated, much higher
SPLs can be generated from the same drive units (vis-à-vis their use in
passive systems) without subjective quality impairment.
11 Modelling of thermal time constants can be incorporated into the drive
amplifiers, helping to compensate for thermal compression by the drive
units, although they cannot eliminate its effects.
12 Low source impedances at the amplifier outputs can damp out-of-band
resonances in drive units, which otherwise would be uncontrolled due to
the passive crossover effectively buffering them away from the amplifier.
13 Drive units are essentially voltage-controlled, which means that when
coupled directly to a power amplifier (most of which act like voltage
sources) they can be more optimally driven than when impedances
are placed between the source and load, such as by passive crossover
components.
14 Direct connection of the amplifier and loudspeaker is a useful distortion
reducing system. It can eliminate the strange currents that can often flow
in complex passive crossovers.
15 Higher order filter slopes can easily be achieved without loss of system
efficiency.
16 Low frequency cabinet/driver alignments can be made possible which, by
passive means, would be more or less out of the question.
17 Drive unit production tolerances can easily be trimmed out.
18 Driver ageing drift can easily be trimmed out.
19 Subjectively, clarity and dynamic range are generally considered to be
better on active systems compared to their passive equivalents (i.e. same
boxes, same drive units).
20 Out of band filters can easily be accommodated, if required.
21 Amplifier design may be able to be simplified, sometimes to sonic benefit.
22 In passive loudspeakers used at high levels, voice-coil heating will change
the impedance of the drive units, which in turn will affect the crossover
termination. Crossover frequencies, as well as levels, may dynamically shift.
Actively crossed over loudspeakers are immune from this effect.
23 Problems of inductor siting, to minimise interaction with drive unit voice
coils at high current levels, are nullified.
24 Active systems have the potential for the relatively simple application of
motional feedback, which may come more into vogue as time passes.
Conversely, the list of benefits for the use of passive, high level crossovers
for large studio monitors would typically consist of:
1 Reduced cost? Not necessarily, because several limited bandwidth amplifiers
may be cheaper to produce than one large one capable of driving complex
loads. (The loudspeaker may be cheaper but the system more expensive).
2 Passive crossovers are less prone to being misadjusted by studio engineers.
True, but in a professional studio one ought to be able to expect a degree of
responsibility in the use of professional systems. However, passive systems
have a tendency to adjust themselves with age.
3 Simplicity? Not really, because very high quality passive, high-level crossovers
can be hellishly complicated to implement, not to mention the amplifiers
which are needed to drive them.
4 Self-containment of the loudspeaker system: but this is probably only
interesting for hi-fi enthusiasts who wish to use them with their favourite
amplifiers.
5 Ruggedness? No; because the electrolytic capacitors (necessary for the
large values) are notorious for ageing, and gradually changing their values.
It is interesting, because you combine two apparently independent categories in one question:
Buy - build
Active -passive
However, i think those categories are not that independent.
"Buying" follows the market and the rules of consumption. Part of this market and it's traditional "consuption rules" is the possibility to buy parts and easily combine them (amps and passive speakers). Many people read magazines and then buy gear and are happy if someone told them their gear is good. It's not important for many to understand what's going on. Complex and possibly messy systems with lots of cables are not desirable. The product (as defined by market) is central element.
" building" is quite the opposite. That means going into technical details and trying to understand principles and construction techniques. Understanding complexity is central element and enjoyable for many builders. The process is central element. That includes going beyond consumer market rules and thus considering active speakers.
Buy - build
Active -passive
However, i think those categories are not that independent.
"Buying" follows the market and the rules of consumption. Part of this market and it's traditional "consuption rules" is the possibility to buy parts and easily combine them (amps and passive speakers). Many people read magazines and then buy gear and are happy if someone told them their gear is good. It's not important for many to understand what's going on. Complex and possibly messy systems with lots of cables are not desirable. The product (as defined by market) is central element.
" building" is quite the opposite. That means going into technical details and trying to understand principles and construction techniques. Understanding complexity is central element and enjoyable for many builders. The process is central element. That includes going beyond consumer market rules and thus considering active speakers.
See if I have to purchase that definitely gonna be Passive. But if I have to build I would like to go Active over Passive because of crossover building.
Buidling does not necessarily mean designing. Many of us here simply build DIY designs that are done by people who are far more experienced and capable of creating designs than we are.
In many cases those designs have been brought to the market in the form of kits, which makes the procurement of parts quite simple as well as providing some financial remuneration for the original designer.
The vast majority of those designs, however, are passive. There are very few examples of active speaker DIY kits.
Designing crossovers is difficult, particularly if you don't have any experience in doing it. However, building them from someone else's design is not difficult at all. Even if you have never soldered before, it is something that can be quickly learned with just a little bit of practice.
I think you are minimizing the real complexity of an active system that requires a separate amplifier for each driver compared to a much simpler arrangement with passive speakers that requires only a single two channel amplifier.
I think implementing 3 dedicated amp modules is much easier than trying to tune the 3-way crossover to get three drivers close to being flat.
And if I have to copy the crossover designed by others for a 3-way which is hard. But even then will have to copy thr drivers and the enclosure as well. Which may not be possible as unable to find same drivers or the design of enclosure may not be good etc.
1, 6, 15, 16 and 20 are good points as far as I'm concerned. So is 24, although I wouldn't call motional feedback simple.
2, 3 and 10 relate to clipping, you shouldn't allow clipping in the first place. It may sometimes be inevitable in PA applications, but not for domestic music listening.
4, 5, 11 and 22 are all true, but I wonder how relevant they are at moderate levels.
7, 9 and 23 are hardly an issue anyway.
I wonder what 8 and 19 are based on.
12 is only true if those resonances are big enough to cause peaks in the driver impedance, the fundamental resonance of a tweeter for example. You can also correct for that with an LRC series network across the loudspeaker.
I disagree with 13, 14 and 21.
17 and 18 are true if you can measure it accurately enough.
I think the main disadvantage of active loudspeakers is the extra costs of all the power amplifiers you need to build. You can keep that limited if you don't mind using chip amplifiers. Besides, you can't combine the power supplies when half of the amplifiers are built into the left loudspeaker and half in the right, unless you run a DC cable from one to the other.
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Not really. I'm in the process of moving house and the added work to dismantle and reassemble is trivial. I've been designing and building active systems for over 30y.
What if you give them a passive system? Do you really think most people ever do more than plonk the speakers down where they want them and use them?
At least you can; passive gives you very few options.
These are probably the silliest reasons I've ever heard for not having an active system. Next you'll be telling me the ghosts in your home won't approve.
That is funny. Seriously I do plan to give it to Family members and set it up for them. But I don't see them moving it unless they plan to move to new Home which they most definitely won't. There is no other suitable room to have Home-theater setup besides the Living Room. So not gonna be an issue anyways.
I cant agree if you guys trying to tell me that implementing and soldering 3 amp modules per Speaker gonna be difficult than building 3-way crossover by trail and error method then that is considered a Joke.
Seriously you guys are looking at number of components going in per speaker but are you actually considering the complexity to build a good really decent 3-way crossover. Number of components outweigh complexity of crossover by a great margin as the work needed is not required and the component cost for trail and error gonna cost as much as the amps for all the speakers and on top of that even after going through all that pain I may not get the expected result may be close to it but not perfect. With DSP I can achieve that. So that is much easy and sure to work process.
I would suggest you do further research in this area, I don't see this information as helping your current position.
Yeah I was trying to figure out if there any major drawbacks of going Active speaker route. But it seems there are none. Not that anything serious was discussed here till now in this specific thread. So am not sure yet if I should go for it or not. Still am finding for the info to be assured.
I have managed to achieve the same level of performance using both methods, no drawbacks in the result. It comes down to understanding what to do with a speaker, and not only how to do it.
Planning to build 11 3-way speakers for Home-theater. what is your opinion on that. Will be using for Movies as well as Music but Music is not main usage. Possibly split 80/20.
Am building DIY Subs anyways. But am not sure on Speakers hence doing some research.
Am building DIY Subs anyways. But am not sure on Speakers hence doing some research.
What are the Compromises. Please can you list them.
This is the kind of info I am looking for.