I.C.E without additional amps

[Dunno]

Haha, don't confuse him anymore. Your last liner may mislead him into thinking passive setup is the best

 

Home and car audio envionments are different.

[Hyun]

but that wasn't quite what i was driving at. the main reason "active" setups sound different, and usually better, than "passive" setups in car audio is not due to the nature of crossover used. that's why i ask specifically, what is it in "active" that's so special. cos it's really not the crossover.

 

again, i reiterate that the word "active" is a misnomer, because what makes the setup better isn't because u're using a powered (i.e. active) crossover as opposed to an unpowered (passive) one. it's mainly because of individual speaker control, including time alignment.

 

therefore, going by this argument, you can have an entirely passive system, WITH individual speaker control in a similar manner. in this setup, it's technically "passive", but has the same benefits that people use the word "active" to describe.

 

and to spoonfeed the answer to this question:

yes, you can achieve the same thing using a head unit to individually control 4 or 5 channels of sound - 2 tweeters, 2 midbasses, 1 subwoofer, in the same way an "active" setup controls the sound, but STILL using crossovers which may not be active crossovers located in the headunit/processor. they could be, a) passive crossovers, b) crossovers located in the amps, c) an external crossover unit.

 

and to complete answering this question, yes, a typical 17W RMS headunit is able to produce pretty good sound in this manner. the limitation is in the 17W RMS - you can only play a midbass or subwoofer up to this output level, which is very decent for most music, but it would be hard to go above 100dB output without clipping.

[Zerstorer]

Agree with the rest of what you say but just would like to add on to the following.

again, i reiterate that the word "active" is a misnomer, because what makes the setup better isn't because u're using a powered (i.e. active) crossover as opposed to an unpowered (passive) one. it's mainly because of individual speaker control, including time alignment.

 

therefore, going by this argument, you can have an entirely passive system, WITH individual speaker control in a similar manner. in this setup, it's technically "passive", but has the same benefits that people use the word "active" to describe.

 

Let's take time alignment out of the equation because that's part of EQ/Processing and has nothing to do with crossover settings.

In electronics, an "active" crossover is simply a crossover that is not only able to attenuate, but also provide gain to the passband. A "passive" crossover would simply attenuate.

Among audiophiles, it is common to use "active setup" to describe a system where the crossover is applied BEFORE amplification as opposed to a "passive setup" where the crossovers are used after the amplifiers.

This is a common use term that is now widely accepted in the community.

 

Active setups like this in hi-end home audio come from brands such as Naim, Midgard, Logt Audio.etc but they are NOT popular for the simple reason that it requires you to buy the entire setup including the amplification with the speaker. Hence there is no cross component compatibility which puts off most purchasers. Ironically, for pro-audio most speakers are active.

 

In a "passive" setup, the full bandwidth of the musical signal is amplified and sent to the speaker, where the crossover would simply dissipate the unwanted frequencies for the respective drivers.

 

The key benefit of "active" setups is that amplifier power is not wasted. The signals are split into the individual bands before they are sent to the amplifier, hence the amp is loaded with only what the driver would ultimately use. Each driver then has a separate signal and return path to the amplifier and this also reduces any distortion due to signal modulation between the various frequencies.i.e you may not have excessive bass current draw affecting your tweeter.

 

That is the basic fundamental functional difference between an active and passive setup. But there are also additional differences due to how current components are made.

 

Passive crossovers in package car component speakers typically only use 2nd order 12dB/octave slopes at most. This is due to phase shift considerations and also to maintain the size and complexity of the resultant crossover.

 

The crossovers in headunits are generally digital crossovers that are applied using processing rather than analog filtering. Hence you can have 6-24/dB slopes on multiple channels easily in just a tiny package.

 

Steeper slopes allow you to use a wider bandwith for each driver before it hits its breakup or resonant point. Thus this may help you optimize your setup better...if you can blend the sound properly.

 

In a hostile car environment, an active setup allows you to manipulate the various passband gains and crossover slopes in addition to standard TA/EQ to help smoothen any severe response peaks/dips. Those with passive setups would be limited to only using TA/EQ since and slight adjustments in the passive crossover which typically vary by 2-3dB on the entire band.

 

Thus, in theory, an active setup can potentially make your components perform at a higher level, with the given caveat that you are able to tune so many variables coherently and get a smooth response. This is usually very difficult without a RTA system.

 

The main issues with active setups are complexity and cost, you must be prepared to tackle all the issues, otherwise a passive setup would more than suffice.

[Hyun]

"In a hostile car environment, an active setup allows you to manipulate the various passband gains and crossover slopes in addition to standard TA/EQ to help smoothen any severe response peaks/dips. Those with passive setups would be limited to only using TA/EQ since and slight adjustments in the passive crossover which typically vary by 2-3dB on the entire band."

---

 

those with passive setups would share a common TA value for both or all 3 speakers (tweeter+midbass+?midrange?) on one side (left, right) which defeats some of the purpose of time alignment. instead of getting precise alignment, this will end up being an "agaration" alignment - with the right side somewhat delayed from the left. there will still be timing mismatch - between the 2 or 3 speakers on one side. this mismatch will end up causing problems of uneven blending at the crossover point, where some frequencies will be constructively added together, and others will be in various extents of destruction. it will sound better than totally no time delay, but these misalignments end up giving illusions to the brain when the signals do not get reconstructed as intended by the software (CD).

 

so i donno whether you want to call this "a bit of TA is better than no TA", or "mai hiam buay pai" but the point is, out of alignment tio si out of alignment.

 

once the output from the source (software, CD) is misaligned, anything else done to correct the output to reconstruct it back to something similar to its intended output would be flawed. can you imagine trying to reconstruct output timing, when the problem lies with the TIME rather than the amplitude? some will try to approximate using phase but all this is trying to fix the obvious problem - TIME, with solutions which are NOT time. you just don't get the final intended output.

 

then we start to imagine things .... "yeah, i think your singer is in the centre ... i THINK...."

[Hyun]

"The main issues with active setups are complexity and cost, you must be prepared to tackle all the issues, otherwise a passive setup would more than suffice."

---

 

that's the gist of this thread. with this sentence, you have ranked active setups as 1) more complex, 2) more costly, and that if the issues are not settled, 3) passive setup would be better.

 

our thread starter wanted a system without outboard amps.

 

1) it makes things LESS complex in a way - you no longer have amps. it increases the complexity because you now wonder, where is the crossover?

 

2) it makes things less costly, you don't spend money on amps any more. but the crossover how? need to spend money on that?

 

3) passive setup sounds better? a large number of "passive setups in local car audio scene" have no attentuation done between tweeter and midbass, and also have TA sharing, as described in the previous post. whether this illusion sounds better than the other illusion of a cheap ampless "active" setup - i have confidence that the cheap one would tend to sound better. the only problem lies in using the 17W RMS onboard amp to play loud - you're limited to about 95-98dB output level.

 

so how can a cheap system be done?

 

1) so where is the crossover? not on amp, one obvious way is to get an external crossover. but that increases cost, and runs the risk of having noise induced by cheapo products. another obvious way is to use crossovers selectable on head unit, but most values may not be suitably in the 3khz region. the final way is to use a PASSIVE crossover.

 

and that's why i say using the word "active" doesn't describe why this method is superior to the typical "passive" system. it's not the ACTIVE that makes it interesting. it's everything else that a typical "passive" system doesn't get. the crossover in the end would be a simple cheap passive crossover - either one which is ready-made or one which is modified or constructed from scratch.

 

that's where the complexity starts.

 

2) the cost can be quite low because many people throw crossovers away and even though they're low-end components, the "bad acoustics" in using these low-end components in the correct manner would probably be preferred to using "good components" in an incorrect manner.

 

Summary:

component 1: head unit with 4 or 5 channels output at speaker level (amplified) - probably 4, cos sub-out is nearly always unamplified. doesn't mean u can't play sub. u can still cheat by tapping sub channel from the 2 midbass outputs, but that'll be stretching your 17W RMS pretty thin.

 

component 2: passive crossover, one network per channel, with attentuation circuit.

 

component 3: each individual speaker linked to each channel.

 

you would then have 1) individual speaker TA, 2) individual speaker attenuation, and in some head units - 3) individual speaker EQ.

 

win liao.

[Zerstorer]

those with passive setups would share a common TA value for both or all 3 speakers (tweeter+midbass+?midrange?) on one side (left, right) which defeats some of the purpose of time alignment. instead of getting precise alignment, this will end up being an "agaration" alignment - with the right side somewhat delayed from the left. there will still be timing mismatch - between the 2 or 3 speakers on one side. this mismatch will end up causing problems of uneven blending at the crossover point, where some frequencies will be constructively added together, and others will be in various extents of destruction. it will sound better than totally no time delay, but these misalignments end up giving illusions to the brain when the signals do not get reconstructed as intended by the software (CD).

 

so i donno whether you want to call this "a bit of TA is better than no TA", or "mai hiam buay pai" but the point is, out of alignment tio si out of alignment.

 

My position is mai hiam buay pai. I've tried it before and also on a friend's setup.

 

As long as the tweeter and woofer positions are chosen with some discretion, you do get a reasonable soundstage.

 

In anycase, the majority of home audiospeakers are neither time-aligned nor phase aligned across their drivers. They still sound pretty ok with decent soundstage even in nearfield listening.

 

When one is faced with limited budget, its all a matter of compromise so you have to choose where to fit your compromises. Some things just have to give at this price point. To get a truly good soundstage requires good source, good drivers and good setup all coming in at once.

 

Basically, I agree with your points and observations. Just clarifying on it since, you didn't elaborate on what you really mean initially.

[Hyun]

> limited budget

 

just trying to point out that, on that limited budget, the gains derived from individual driver control generally outweighs the gain from running a typical passive setup - cos more faults in car audio are corrected in the above suggested model than the typical passive setup, which leaves most of the glaring faults uncorrected. but to do up this cheap controlled setup requires some knowledge in passive crossover design.

 

> majority of home audiospeakers are neither time-aligned nor phase aligned

 

the misalignment is slight and doesn't mar the sound in an obvious manner. the misalignment in tweeter-midbass is nearly symmetrical as well, even if the listening position is off-centre. and at the typical 3khz region, it takes about 5cm before total cancellation occurs, and for that to happen, there must be quite a drastic shift in vertical listening position, which normally doesn't happen mah. as for phase alignment, think most manufacturers are clever enough not to choose crossover orders that go into phase conflict leh?

 

> I've tried it before and also on a friend's setup.

 

wanna share these setup designs?

[Zerstorer]

I'm was an Eclipse 7100 and my friend is on Alpine 9887 both using Hertz HSK 165.Initially we had our setups installed in the same way, the only difference with me running active. In any case my setup has been changed quite abit so I'll just decribe his. He's running passive direct from headunit on the "compromised" unified T/A setup as you described. His tweeters are mounted at edges of dashboard directed at driver's position.

 

Don't expect holographic imaging but lateral soundstage spread is stable and consistent, just like what you would get on a similar $400 home audio speaker.

 

I have switched my tweeters in another location that results in only stable imaging for the driver(even if TA is adjusted for passenger) possibly due to the issues you described or reflections because of the non-symmetrical dashboard layout. But the previous location worked well enough without significant differences in tonality.

 

Anyway I'm lost as to what your current position is:

>

just trying to point out that, on that limited budget, the gains derived from individual driver control generally outweighs the gain from running a typical passive setup - cos more faults in car audio are corrected in the above suggested model than the typical passive setup, which leaves most of the glaring faults uncorrected. but to do up this cheap controlled setup requires some knowledge in passive crossover design.

 

Anyway I'm lost as to what your current position is, but the above seems that we are in agreement on the issue?

[Hyun]

i also a bit lost hehe but the gist of what i was trying to illustrate was:

 

1) the feature in "active setup" is not the "active"ness of the crossover, but actually the independent driver control. whether the crossover is active or passive has hardly any bearing because there are other glaring faults in a car system that needs to be corrected.

 

2) this "active" or rather "independent" setup can be achieved by running off a suitable headunit at the typical 17W RMS per channel. all that limits you to is a max volume output, as well as the quality of the head unit's amplification (as if we can tell, since again, we have other glaring faults to correct) ...

 

3) this "independent" setup might likely require passive crossover tinkering which will require some knowledge there. the cost can be low - again, the gains from buying expensive components probably pale in comparison to the glaring faults we're trying to correct.

 

so in this setup, we try to correct these "glaring faults", which will make more of a difference in the sound compared to 1) using active crossovers, 2) buying expensive amps, 3) using other expensive components.

[Zerstorer]

Haha..it seems that there is no disagreement at all.