# So how much power is lost due to passive crossover networks?



## impulse (Jul 5, 2014)

I was watching some old episodes of Amplified Q&A and Doug mentioned about how those passive crossover networks for your components can drop a lot of your power that your sending to them. What % is wasted?

So do the more complicated passive crossovers waste more power than the simpler, cheaper ones? Does this effect coaxials just the same as components or do the coaxials receive a higher % of power since they use simple filters?


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## GEM592 (Jun 19, 2015)

impulse said:


> I was watching some old episodes of Amplified Q&A and Doug mentioned about how those passive crossover networks for your components can drop a lot of your power that your sending to them. What % is wasted?
> 
> So do the more complicated passive crossovers waste more power than the simpler, cheaper ones? Does this effect coaxials just the same as components or do the coaxials receive a higher % of power since they use simple filters?


I don't have any numbers for you, but I would say that while there is some power loss for sure, it is pretty minimal - even more or less negligible. It depends on the crossover, how it is set up, how it is being driven, etc, and any number would be some aggregate approximation that wouldn't be really helpful anyhow.

If you're asking in the context of active vs. passive setups, crossover power loss isn't a top motivation for going active.


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## smgreen20 (Oct 13, 2006)

According to the Loudspeaker design cookbook, Generally it's 5% power loss for every order slope.

6dB = 5%
12dB = 10%
18dB = 15%
24dB = 20%

and so on.


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## impulse (Jul 5, 2014)

smgreen20 said:


> According to the Loudspeaker design cookbook, Generally it's 5% power loss for every order slope.
> 
> 6dB = 5%
> 12dB = 10%
> ...


Good to know. Thanks. I'm sure 10% likely isn't noticeable at all.


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## gumbeelee (Jan 3, 2011)

I refuse to speak the word “passive” this day in car audio because they are no since in it. Passive is for people that are not living “Active”



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## Ifixtheinternet (Jan 29, 2016)

IMO there are several other power concerns than the actual power loss through the crossover from the amp to the speakers.

1. When running a passive crossover network, generally you are connecting a wire to one channel of an amp to feed two speakers, instead of each speaker to a dedicated channel. This alone splits your available power in half. If you have a 4 channel amp you can bridge, then this can become a non-issue.

2. Normally when running passive, you send a full range signal from the amp to the crossover, only to have the crossover cut off frequencies not needed, and roll-off others.
So the amp wastes energy creating frequencies you're not even using (for that speaker pair), or will be attenuated. When you run active, you have all the available amp power to create only the sound that will be produced by the speakers. If you are sending sub frequencies 20-80hz, those take the most energy to produce and will just be cut off by the crossover.

3. Marginal, but having two extra wire splices between the amp and speaker never did any good, nor does having longer / more pieces of wire.

Add all these things together with the actual power loss through the crossover and you're probably getting half the power you'd get running active on the same amp, at best.








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## Holmz (Jul 12, 2017)

Ifixtheinternet said:


> IMO there are several other power concerns than the actual power loss through the crossover from the amp to the speakers.
> 
> 1. When running a passive crossover network, generally you are connecting a wire to one channel of an amp to feed two speakers, instead of each speaker to a dedicated channel. This alone splits your available power in half. If you have a 4 channel amp you can bridge, then this can become a non-issue.
> ...


Let's stick with facts...

The passive does not split the power in half anywhere but at the crossover point.




Ifixtheinternet said:


> I
> ...
> 
> 2. Normally when running passive, you send a full range signal from the amp to the crossover, only to have the crossover cut off frequencies not needed, and roll-off others.
> ...


Ideally the amp is not creating anything that is not coming into the input.
So those frequencies usually go to the speaker that cross over if feeding.

Many amps have sub filter, and the inline filters have been around since well before DSPs ("Since time dot").




Ifixtheinternet said:


> I
> ...
> 3. Marginal, but having two extra wire splices between the amp and speaker never did any good, nor does having longer / more pieces of wire.
> 
> Add all these things together with the actual power loss through the crossover and you're probably getting half the power you'd get running active on the same amp, at best.


Even if it was half, most people cannot hear hear half or double, and one just turns the volume up or down anyhow.

The is some elegance in a passive system with a 2 channel amp that would avoid multi channel bridged complex systems that may not sound all that ideal anyhow.


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## minbari (Mar 3, 2011)

Ifixtheinternet said:


> IMO there are several other power concerns than the actual power loss through the crossover from the amp to the speakers.
> 
> 1. When running a passive crossover network, generally you are connecting a wire to one channel of an amp to feed two speakers, instead of each speaker to a dedicated channel. This alone splits your available power in half. If you have a 4 channel amp you can bridge, then this can become a non-issue.


actually that is not true in the least. if you have a 100 watt 2 channel amplifer and have a 12 db/ oct hp and lp network for a midbass and tweeter, then BOTH speakers get 100 watts! it distributes the power to each speaker, but they dont consume power at the same freq band.


> 2. Normally when running passive, you send a full range signal from the amp to the crossover, only to have the crossover cut off frequencies not needed, and roll-off others.
> So the amp wastes energy creating frequencies you're not even using (for that speaker pair), or will be attenuated. When you run active, you have all the available amp power to create only the sound that will be produced by the speakers. If you are sending sub frequencies 20-80hz, those take the most energy to produce and will just be cut off by the crossover.


again, total crap. ANY amplifier worth its salt can produce full rated power from 20-20khz. it doesnt produce more power if you only feed it a 500-5khz signal. it still produces EXACTLY the same power.


> 3. Marginal, but having two extra wire splices between the amp and speaker never did any good, nor does having longer / more pieces of wire.
> 
> Add all these things together with the actual power loss through the crossover and you're probably getting half the power you'd get running active on the same amp, at best.
> 
> ...


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## Ifixtheinternet (Jan 29, 2016)

minbari said:


> actually that is not true in the least. if you have a 100 watt 2 channel amplifer and have a 12 db/ oct hp and lp network for a midbass and tweeter, then BOTH speakers get 100 watts! it distributes the power to each speaker, but they dont consume power at the same freq band.
> 
> again, total crap. ANY amplifier worth its salt can produce full rated power from 20-20khz. it doesnt produce more power if you only feed it a 500-5khz signal. it still produces EXACTLY the same power.


Maybe I worded this wrong.

If you're sending a full range signal from the HU to the amp, and the amp is also in "all-pass" mode, it puts out, let's call it 50 watts. Then the crossover cuts off the lower range of sound not meant for the speakers. Thus you are left with less than 50 watts for the frequencies actually used.

If you are using an active crossover, the frequencies not meant for the speaker are not sent to the amp at all, thereby allowing the amp all available power to produce the frequencies you want. The energy that was being used to produce, say 30-80hz, is no longer wasted.

You could enable the filter on the amp to mitigate this, but then you have double crossovers which is something you don't want.

Also, connecting 2 speakers to a 100 watt channel does NOT give 100 watts to both speakers. They would be sharing 100 watts.




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## Ifixtheinternet (Jan 29, 2016)

Holmz said:


> Let's stick with facts...
> 
> The passive does not split the power in half anywhere but at the crossover point./QUOTE]
> 
> ...


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## minbari (Mar 3, 2011)

Ifixtheinternet said:


> Maybe I worded this wrong.
> 
> If you're sending a full range signal from the HU to the amp, and the amp is also in "all-pass" mode, it puts out, let's call it 50 watts. Then the crossover cuts off the lower range of sound not meant for the speakers. Thus you are left with less than 50 watts for the frequencies actually used.
> 
> ...


You worded it just fine. That isn't how it works

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## minbari (Mar 3, 2011)

Ifixtheinternet said:


> Holmz said:
> 
> 
> > Let's stick with facts...
> ...


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## Holmz (Jul 12, 2017)

Ifixtheinternet said:


> Holmz said:
> 
> 
> > Let's stick with facts...
> ...


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## minbari (Mar 3, 2011)

Holmz said:


> Ifixtheinternet said:
> 
> 
> > The amp supplies what is asked from it. So a 50w amp will supply between 0-50W.
> ...


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## Holmz (Jul 12, 2017)

minbari said:


> Holmz said:
> 
> 
> > And just to beat a dead horse a little more. The passive is NOT splitting power between the passive components. It is splitting bandwidth
> ...


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## minbari (Mar 3, 2011)

Another consideration (among many), when you get into lower freqs with passive components, the values get very large, the wattage handling gets bigger (physically larger) and so they start to cost a fortune. Try specing parts to build a 12db LPF at 80hz for 500+ watts. Will be hundreds

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## 156546 (Feb 10, 2017)

The power lost through the passive network depends only on the DCR of the components used in the crossover and connected in series with the speakers. For capacitors, that's negligible. For inductors in a 2nd (or greater) order low pass filter, the gauge of the wire is what contributes DCR. Any crossover designer worth his salt is modeling the DCR of the coils to achieve the target response. The DCR of the coil provides a little bit or a lot of attenuation, but for the most part, it's intended. 

Asking this question and being concerned about the result is like asking "How much power is lost when you use an EQ?" A 6dB cut at 1 kHz causes 75% of the power to be lost, even if it's a preamp EQ. Silly.


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## impulse (Jul 5, 2014)

Well let me ask this. Would a coaxial necessarily sound noticeable worse or louder than a component set providing it's from the same series? Such as Infinity Kappa's or Polk DB's..etc


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## minbari (Mar 3, 2011)

impulse said:


> Well let me ask this. Would a coaxial necessarily sound noticeable worse or louder than a component set providing it's from the same series? Such as Infinity Kappa's or Polk DB's..etc


Most of the time, its just mounting. Should sound the same

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## 156546 (Feb 10, 2017)

impulse said:


> Well let me ask this. Would a coaxial necessarily sound noticeable worse or louder than a component set providing it's from the same series? Such as Infinity Kappa's or Polk DB's..etc


Coaxials often have a much simpler crossover with fewer components. If the crossover in a coaxial is just a tiny cap on the tweeter, then the component is likely to be a better performer.

The difference between one brand and another brand is often determined by whether the guy who's designing the speaker and the crossover knows what he's doing.


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## punkrocker (Feb 20, 2018)

Guys if anyone has a clamp meter and volt meter we could just measure some watts before and after the crossover...


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## Holmz (Jul 12, 2017)

GotFrogs said:


> Coaxials often have a much simpler crossover with fewer components. If the crossover in a coaxial is just a tiny cap on the tweeter, then the component is likely to be a better performer.
> 
> The difference between one brand and another brand is often determined by whether the guy who's designing the speaker and the crossover knows what he's doing.


Maybe... but most people run a capacitor on a tweeter, so I do not see a huge difference.

The phase centre of a coaxial's two speakers gives its distinct advantage, whether or not the cross over is "good, bad or ugly".


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## minbari (Mar 3, 2011)

punkrocker said:


> Guys if anyone has a clamp meter and volt meter we could just measure some watts before and after the crossover...


For what purpose?

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## Justin Zazzi (May 28, 2012)

minbari said:


> For what purpose?


This.

What is the motivation behind knowing how much power a passive crossover consumes?

If this is purely for fun and to learn stuff, that's cool and I'd like to help.


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## punkrocker (Feb 20, 2018)

minbari said:


> For what purpose?
> 
> Sent from my LGLS992 using Tapatalk


To see how much various crossovers are consuming watts ie power I suppose. If you measure the speaker wire being fed to the crossover you could see the difference it puts out after the crossover if you add the two together. 
Also I wonder if they change the ohms or anything else if they're cheap.

This might also help people plan their systems better if they can come closer to the ideal rms if they're loosing power to speakers for after a convential crossover over a DSP.


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## Holmz (Jul 12, 2017)

Justin Zazzi said:


> This.
> 
> What is the motivation behind knowing how much power a passive crossover consumes?
> 
> If this is purely for fun and to learn stuff, that's cool and I'd like to help.





punkrocker said:


> To see how much various crossovers are consuming watts ie power I suppose. If you measure the speaker wire being fed to the crossover you could see the difference it puts out after the crossover if you add the two together.
> Also I wonder if they change the ohms or anything else if they're cheap.
> 
> This might also help people plan their systems better if they can come closer to the ideal rms if they're loosing power to speakers for after a convential crossover over a DSP.


I am all for it... Then the OP can document exactly how much is lost - which should be 1-2 dB.
Then everyone can know it is exactly a lil' bit, which does not matter and cannot be heard.


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## minbari (Mar 3, 2011)

Holmz said:


> I am all for it... Then the OP can document exactly how much is lost - which should be 1-2 dB.
> Then everyone can know it is exactly a lil' bit, which does not matter and cannot be heard.


Sounds tedious to me. You would need a signal generator too. No way to test this with music. And you would need to test the whole band. Impedance, as we all know, is frequency dependant.
after you are done, I don't know how you could separate your findings between the xover and the speaker. They are both reactive and in series one effects the other.

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## 156546 (Feb 10, 2017)

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Holmz said:


> Maybe... but most people run a capacitor on a tweeter, so I do not see a huge difference.
> 
> The phase centre of a coaxial's two speakers gives its distinct advantage, whether or not the cross over is "good, bad or ugly".



LOL. There is no "phase center" in a coaxial unless it's something like a Kef Uni-Q driver. Furthermore, the placement of the tweeter above the midrange cone can create some serious intermodulation distortion because the moviing midrange cone is the baffle for the frequencies emitted by the tweeter in the range where dispersion is spherical. The benefit of a typical coaxial is the presence of high frequency content in the off-axis sound. 

The whole point of a crossover is to shape the response in the region that the two speakers play. This idea that a few tenths of an ohm in series resistance is somehow an efficiency thief is ridiculous. By that token, all gain controls should be run wide open and no power robing EQ should ever be used. 

From anything beyond a purely academic exercise in understanding how a crossover works, this thread is ridiculous.


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## Patrick Bateman (Sep 11, 2006)

gumbeelee said:


> I refuse to speak the word “passive” this day in car audio because they are no since in it. Passive is for people that are not living “Active”
> 
> 
> 
> Sent from my iPhone using Tapatalk


Almost every talented loudspeaker designer I know uses both active and passive xovers.

Personally, I'd rather invest $20 into a passive xover than $100 into an amplifier. And it also saves space. And my hybrid crossovers are arguably quieter than a fully active setup.

If you have unlimited funds and space, by all means, go fully active.


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## Ifixtheinternet (Jan 29, 2016)

Patrick Bateman said:


> Almost every talented loudspeaker designer I know uses both active and passive xovers.
> 
> Personally, I'd rather invest $20 into a passive xover than $100 into an amplifier. And it also saves space. And my hybrid crossovers are arguably quieter than a fully active setup.
> 
> If you have unlimited funds and space, by all means, go fully active.


I don't understand this statement.

Whether you run passive or active has nothing to do with having an amplifier or not. You can run active with just the head unit, you will just have significantly less power. And because the physical crossover introduces power loss as discussed here, you will have even less.

The only extra cost with active is (possibly) buying a head unit that is active capable, but there are very inexpensive ones.

Running active is actually less expensive if you consider purchasing raw drivers. My first set of passive components was more expensive than the raw drivers I'm running now, and the raw drivers are way better.

Add the ability to time align and level adjust the drivers individually, and there is no reason not to run active, besides the added setup complexity which some may not want to deal with.


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## gijoe (Mar 25, 2008)

Ifixtheinternet said:


> I don't understand this statement.
> 
> Whether you run passive or active has nothing to do with having an amplifier or not. You can run active with just the head unit, you will just have significantly less power. And because the physical crossover introduces power loss as discussed here, you will have even less.
> 
> ...


You're missing the fact that active needs a channel per speaker. A 2 way active front needs 4 channels of amplification, a passive setup needs only 2 channels. Active is more expensive to amplify. 

In a car, active is a huge help, but only because the car is so unpredictable. At home, a passive network can do just as well, and be a lot less expensive overall. And, in a car, you can still use raw drivers and build a crossover for much less than an active setup. There may be a lot of trial and error to design the crossover, but it can be done for a lot less than a DSP and extra channels of amplification.


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## Ifixtheinternet (Jan 29, 2016)

gijoe said:


> You're missing the fact that active needs a channel per speaker. A 2 way active front needs 4 channels of amplification, a passive setup needs only 2 channels. Active is more expensive to amplify.
> 
> In a car, active is a huge help, but only because the car is so unpredictable. At home, a passive network can do just as well, and be a lot less expensive overall.


I assumed we were discussing vehicles since this is a mobile audio forum. In a vehicle, it makes little sense to go the passive route.

In a home theater / stereo system, I agree it is the norm to have passive crossovers built into the speakers. 






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## gijoe (Mar 25, 2008)

Ifixtheinternet said:


> I assumed we were discussing vehicles since this is a mobile audio forum. In a vehicle, it makes little sense to go the passive route.
> 
> In a home theater / stereo system, I agree it is the norm to have passive crossovers built into the speakers.
> 
> ...


Patrick's post didn't say anything about how much sense it makes, only that it's cheaper, and he's right. A passive setup can be built for a lot less than an active one.


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## Ifixtheinternet (Jan 29, 2016)

gijoe said:


> Patrick's post didn't say anything about how much sense it makes, only that it's cheaper, and he's right. A passive setup can be built for a lot less than an active one.


For your home system, yes it is cheaper.
For car audio, not necessarily.

The total cost for the active system in my car costs less than the passive system I started with, and it outperforms the passive setup in every regard.

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## minbari (Mar 3, 2011)

Sorry don't agree. Spec out parts for a 24db L/R. Lowpass, basspass and high pass filter and tell me that is less than a 3-way active crossover.

Passive has its place and I use it when it makes sense. But there are times it doesn't

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## gijoe (Mar 25, 2008)

Ifixtheinternet said:


> For your home system, yes it is cheaper.
> For car audio, not necessarily.
> 
> The total cost for the active system in my car costs less than the passive system I started with, and it outperforms the passive setup in every regard.
> ...


Just because your current active system is less than the previous passive system, doesn't mean that active is less expensive.

Take a pair of raw 6.5's and a raw tweeters and run them active, or passive. You can build a passive crossover for a lot less than you can buy an active processor. I'm not saying it's worth while, I'd rather take an active setup, but the point is, a passive crossover can be built for a few dollars, and you need fewer amp channels. All things being equal, passive is much cheaper.

You can duplicate the frequency response of the active crossover with passive components. EQ and TA are something else, but the crossover part can be handled very cheaply.


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## gijoe (Mar 25, 2008)

minbari said:


> Sorry don't agree. Spec out parts for a 24db L/R. Lowpass, basspass and high pass filter and tell me that is less than a 3-way active crossover.
> 
> Passive has its place and I use it when it makes sense. But there are times it doesn't
> 
> Sent from my LGLS992 using Tapatalk


Are you factoring the extra 4 channels of amplification that is required? Because, if I understand Patrick's post correctly, that's his point.


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## Ifixtheinternet (Jan 29, 2016)

gijoe said:


> Are you factoring the extra 4 channels of amplification that is required? Because, if I understand Patrick's post correctly, that's his point.


Let's just assume we're still talking car audio here. Virtually every head unit available today has at least 5 individual channels built-in, for front L/R, rear L/R, and sub. 

The only added cost would be getting a head unit that is active capable. If you plan this from the beginning, then it can easily be cheaper, especially considering the mark-up on car specific passive components sets.

If you buy a head unit that is not active capable, then later decide you want to use raw drivers and go active, yes it will be more expensive to add an external DSP than acquire / build a passive crossover.

However that would be your fault for not planning the system design properly the first time.

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## minbari (Mar 3, 2011)

gijoe said:


> Are you factoring the extra 4 channels of amplification that is required? Because, if I understand Patrick's post correctly, that's his point.


You are gonna have a dedicated sub amp. Then the only difference is 2ch vs 4ch for mids. Cost is minimal.

I can tell ya, i have gone the fully passive route before, it's just not cheaper. You want to change slope or freq you have to start all over, re-buy everything. Get done and the tweet is too loud, now you have to buy or build an L-pad. Make sure you stick to odd or even slopes to keep the phase shifts the same.

For what amplifiers cost these days, unless space is an absolute premium. It's not worth it.

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## Patrick Bateman (Sep 11, 2006)

Ifixtheinternet said:


> For your home system, yes it is cheaper.
> For car audio, not necessarily.
> 
> The total cost for the active system in my car costs less than the passive system I started with, and it outperforms the passive setup in every regard.
> ...


That's a good point. I'm buying my crossover parts from eBay and surplus houses, so it's fairly cheap.

For instance, I know enough about passives to know that I can use a $1 cap if it's not in the signal path.

But back when I was getting started out with this, I would purchase $5-$10 caps from Solen and I'd wait two weeks for them to arrive.

Nowadays, I just have a shoebox full of caps and inductors. I make the crossover with cheap parts, and once I get the whole things sorted out I replace the parts in the signal path with better quality parts.

If you're not careful, it's fairly easy to spend $60 on a passive xover.

I try and go passive where I get the most 'bang for the buck.' Here's an example:

The conventional way to do car audio midranges is to run them on a dedicated channel. So you're probably using one half of a four channel amp, and one half of a DSP. A total cost of about $200. (This assumes you're using *half* of two components.)

The way that I do them is that I 3D print an enclosure. I 3D print the enclosure so that it's small enough not to require a high pass. You see the same thing in a lot of prosound speakers, basically if you make the back chamber really small, the enclosure itself will prevent overexcursion. So that takes care of the high pass, which is the REALLY expensive part of a midrange crossover. For the lowpass, I generally use one inductor and 1-2 caps. That's a cost of about $15 per channel.

In the end, I've saved about $70.

As time grinds on, these decision will probably become pointless. Amps keep getting cheaper and so does DSP. Once I can build or buy an eight channel DSP for less than $150, passives will start to seem kinda pointless.

Hell, I am actually talking MYSELF out of using passives:

I have a speaker project in the garage RIGHT NOW and I've been procrastinating about finishing it because this is the part of the project that I HATE. Basically the problem here is that the best way to do passives is to do them on a PC, and I hate doing that. It's a p.i.t.a. to measure the raw response, build a PC simulation, and then tweak. I can do the process in about eight hours, but it's drudgery. And then there's another 2-3 hours to assemble the crossover properly. And the thing I REALLY hate about all of this, is that I frequently find that I'm not 100% happy with the results, so then I go back to square one. Which requires another five hours or so.

If you guys have wondered why my projects always go off the rails at the crossover stage, that's why.

Maybe I should spend the extra $70 and just go active 

In the big scheme of things, I'm basically putting in an extra 5-15 hours to save $70.

From that perspective, maybe that's why passives are so popular in the audiophile community. If you're building a thousand speakers, it makes sense to invest 5-15 hours to make the final product $70 cheap. Amortized over 1000 speakers, that's a savings of $70,000. That means that a 10hr investment pays off at a rate of $7000/hr. But when I'm building ONE speaker and doing it with passives, I'm basically working for approximately $7 per hour to save that $70.


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## Holmz (Jul 12, 2017)

minbari said:


> Sounds tedious to me. You would need a signal generator too. No way to test this with music. And you would need to test the whole band. Impedance, as we all know, is frequency dependant.
> after you are done, I don't know how you could separate your findings between the xover and the speaker. They are both reactive and in series one effects the other.


I was thinking a tone and a volt meter, and using whatever speaker he has in there, using a tone...
One either needs to measure voltage across the speaker, current flow, heat generated, or SPL.

For instance high pass filter some music and play the track out of a CD though the "Xover -> speaker" and without the Xover, and then use an SPL meter to measure SPL.
I like the SPL measurement as that is a bit more meaningful than a more dire sounding "20% loss".

A scope, or an SPL meter seems like the two tools that would be most easily used.


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## Patrick Bateman (Sep 11, 2006)

Side note:

This is an alternative to low pass filters, and IMHO, there's almost no reason not to go this route. This solution costs virtually nothing, and it is the only solution which allows you to do two powerful things:

1) reduce distortion

2) widen beamwidth

http://www.diymobileaudio.com/forum...ssion/82067-diy-reducing-speaker-beaming.html

Nexo, DSL, JBL and L'Acoustic are the ones who are doing this currently, but as time wears on, I think you will see this become commonplace. This solution has many many advantages and nearly no drawbacks.


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## Holmz (Jul 12, 2017)

GotFrogs said:


> ```
> 
> ```
> ...
> ...


Well if the OP wanted to measure it then they would know for sure.
I assume that the 5- 20% they threw out would be accurate.
And that is somewhere between 0-1dB(A) in SPL.

It is an academic fact the each speaker has a phase centre, and that reducing TA differences is generally a good thing... plus sometimes speaker realestate can be difficult.
If I was running a coaxial, then I would not be concerned with using its supplied passive cross over.


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## edub13 (Jun 19, 2015)

Maybe I'm way off on the intent of the OP here, but I'll weigh in with a couple thoughts that the OP stirred in my head.

In an AC circuit, there are three components of power, apparent power (VA), true power (Watts), and reactive power (VAR). True power is the power consumed doing useful work, apparent power is what your production and distribution equipment "sees", and the reactive power is "lost" in the phase shift between voltage and current. The relationship between the three components is illustrated in a right triangle with VA as the hypotenuse, Watts as the adjacent, and VAR as the opposite. I usually describe it as the kVA is the mug, kW is the beer, and kVAR is the foam. 

The whole power triangle thing becomes wildly complex and pretty much inadequate to describe the stuff going on in an audio circuit with the wildly varying frequencies and the resultant changes in total load impedance. However, there is still alternating current driving an inductive motor, add in the passive crossover scenario there are additional reactive components. So at any given time, one could have a wildly varying power factor. Whenever there is an excessive reactive load, there is less power doing useful work (driving the speaker motor in this case), so maybe (?) this is the "power loss" in question?

Was the original question how much foam do we have in our beer? Or is it something else?

:laugh:


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## minbari (Mar 3, 2011)

edub13 said:


> Maybe I'm way off on the intent of the OP here, but I'll weigh in with a couple thoughts that the OP stirred in my head.
> 
> In an AC circuit, there are three components of power, apparent power (VA), true power (Watts), and reactive power (VAR). True power is the power consumed doing useful work, apparent power is what your production and distribution equipment "sees", and the reactive power is "lost" in the phase shift between voltage and current. The relationship between the three components is illustrated in a right triangle with VA as the hypotenuse, Watts as the adjacent, and VAR as the opposite. I usually describe it as the kVA is the mug, kW is the beer, and kVAR is the foam.
> 
> ...


Well said! Even more reasons why figuring out that mess is nearly impossible with a dmm

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