# Why Is Everyone Using Active Crossovers?



## Patrick Bateman (Sep 11, 2006)

People on here are frequently recommending that active crossovers should be used in lieu of the passive crossovers which come with their component speakers.

This is mystifying to me. IMHO the crossover is the most critical component in any loudspeaker. It can take months or even years to perfect a passive crossover.

So why trash a perfectly good passive crossover in favor of an active crossover?

I know that car audio installers routinely recommend this because it's an easy way to sell two extra amps and a crossover. But if you're doing it yourself, what's the point?

(Also, I'm NOT talking about the crossover from subs to midbass. I'm talking about midbass to midrange, or midrange to tweeter.)


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## ehiunno (Feb 26, 2008)

I hate to tell you to search first, but this has been covered numerous times. In-car response is far too difficult to predict accurately enough to design a passive crossover before actually putting it in the car. 

http://www.diymobileaudio.com/forum/diyma-tutorials/7160-basic-guide-crossovers.html
http://www.diymobileaudio.com/forum/diyma-tutorials/17429-basic-guide-crossovers-part-2-a.html

There, minivanman models some drivers in attempt to predict in car passive capabilities and essentially shows it isn't possible to design a universal passive crossover system for car. Being able to install the drivers then measure then design the crossover isn't a luxury most people have.


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## benny (Apr 7, 2008)

Jeebus, I love your posts Patrick, but really?


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## Patrick Bateman (Sep 11, 2006)

ehiunno said:


> I hate to tell you to search first, but this has been covered numerous times. In-car response is far too difficult to predict accurately enough to design a passive crossover before actually putting it in the car.
> 
> http://www.diymobileaudio.com/forum/diyma-tutorials/7160-basic-guide-crossovers.html
> http://www.diymobileaudio.com/forum/diyma-tutorials/17429-basic-guide-crossovers-part-2-a.html
> ...


When you put loudspeakers in a car, the frequency response just goes to hell. In the thread you're referring to, MinivanMan models a passive crossover using published data off the internet. He didn't measure the loudspeakers in a car. Here's a pic of his simulation:










Here's an honest-to-God measurement of a loudspeaker inside of a car. My car, my measurements:










What we see are just MASSIVE swings in the frequency response. There are multiple traces because I measure at multiple locations. Optimizing the response at one location is short-sighted.

The reason we get all these dips and peaks is that moving a speaker even a single inch can create peaks on the level of 6db, and dips as deep as 20db. Just one inch!!!

Companies like JBL take this into account when they design a passive crossover. What they do is measure the speaker at multiple locations, to create a response that's good overall, instead of a single location.

Needless to say, that requires a tremendous number of acoustic measurements, literally hundreds.


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## ChrisB (Jul 3, 2008)

I want to run active because it makes my e-penor 12 miles long.:laugh:


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## 89grand (Nov 23, 2006)

After going active my first time, my system sounded a lot better than all of the passive systems I had ran before in the past and those passive setups were not cheap entry level junk components, but old (good) Reference MB Quarts and Focal 130k's.

In a home stereo I agree you should probably leave the crossover alone, but in a car, no mass produced generic passive crossover is going to be able to take into account the car, the install, and whatever else effects the frequency response. Going active allows me to infinitely adjust the levels between the mid and tweeter (not just -3/0/+3db on the tweeter), to pick the frequency and slope of the crossover that best suites my system, and another big plus, is it allows me to change out drivers without having to buy or design a whole new passive crossover that may or may not work in my setup. Also, the system is cleaner over all when used bi-amped than through the passive set since the mid and tweeter are independent of each other so even if the mid amp is clipping, the tweeter amp is not.

****, it's cheaper often times to go active when you don't have to buy and over priced car audio component set. Picking raw drivers has many advantages over a passive set, both in cost and quality. This site was founded on raw drivers making active setups almost mandatory, but it has its advantages even without using raw drivers.

I personally can't see even one advantage to a passive crossover in the car. I'd even say that many passive car audio crossovers (especially more entry level sets) aren't even designed very well in the first place.


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## David_Edwards (Nov 12, 2008)

Passive crossovers have Insertion Loss. Insertion loss is the passive crossover network "stealing" power from the amplifier; without passive crossovers between the amplifier and speakers, especially large inductors for the midbass speakers, you can effectively expect (up to) twice the "real" power of the amplifier being delivered to the speakers, and not being wasted as heat energy in the passive crossover. Likewise, with the use of active crossovers, at least a small reduction in intermodulation distortion can be expected because the amplifier’s damping factor is greatly improved for the midbass loudspeakers. Additionally, the highpass crossover network built into many amplifiers provides an effective way of fine-tuning the desired response of the midbass driver in the two-way component set. Elimination of the low frequency passive crossover, its inherent losses, potentially poor linearity and crossover point inaccuracy will significantly improve the performance of the midbass driver.


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## capnxtreme (Feb 5, 2008)

Given this:



Patrick Bateman said:


> The reason we get all these dips and peaks is that moving a speaker even a single inch can create peaks on the level of 6db, and dips as deep as 20db. Just one inch!!!


And given that the mid/tweet distance and relationship is going to be drastically different in different cars, you don't think the additional tuning ability of an active crossover is beneficial?


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## capnxtreme (Feb 5, 2008)

David_Edwards said:


> Passive crossovers have Insertion Loss.


This couldn't be any further from the answer to the OP's question--it has absolutely nothing to do with why active is usually recommended here FOR A CAR. You're just rambling about the theoretical benefits of an active speaker system, in general. That's pretty clearly not what the OP was asking.


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## ehiunno (Feb 26, 2008)

Patrick Bateman said:


> When you put loudspeakers in a car, the frequency response just goes to hell. In the thread you're referring to, MinivanMan models a passive crossover using published data off the internet. He didn't measure the loudspeakers in a car. Here's a pic of his simulation:
> 
> Here's an honest-to-God measurement of a loudspeaker inside of a car. My car, my measurements:
> 
> ...


And if you were to take the same speaker, and mount it in a different place, you would get different response, and need a different crossover. The same is true for a different car. I don't care how many times JBL measured the driver in a door if I am putting it in a kickpanel. Likewise, its irrelevant how many times JBL measured their speakers in a mini-van if I am putting it in a Civic. Get the picture? And if they measured it in kickpanels, doors, minivans, trucks, and small cars, they HAD to optimize it for one, and yet the don't tell us which.

and if they found that in each of those situations that they needed the exact same passive crossover, then _they did something wrong_


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## ctrhenry (Jul 16, 2006)

people like to fiddle with the knobs...........................

I like the sound of components with well built passive crossovers. The problem for most if they are unhappy with what came with their components or they have mixed and matched raw drivers that no passive exist for they are then tasked with build/test/build passives until the get it right or go active.

What is the downside of going active ? if it is a well built active. For example the new Pioneer HU that has everyone drooling the DEX-P99RS with all the processing built into the unit

RCAs straight to the amplifier and speaker wire straight to the drivers.

buy some software for your laptop, a mic and tweak away.


I know passive crossover components are inexpensive compared to a 800 dollar processor but most people even the extremely talented DIYer can get cold feet just hearing 4th Order Linkwitz-Riley. 


(big fan of your waveguides thread, glad I have powerful 3d modeling and rapid prototype equipment, I just need a laser scan of my cabin and the huevos to try it)


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## ctrhenry (Jul 16, 2006)

capnxtreme said:


> This couldn't be any further from the answer to the OP's question--it has absolutely nothing to do with why active is usually recommended here FOR A CAR. You're just rambling about the theoretical benefits of an active speaker system, in general. That's pretty clearly not what the OP was asking.


but it is helpful information for the noobs.....no?


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## Patrick Bateman (Sep 11, 2006)

89grand said:


> After going active my first time, my system sounded a lot better than all of the passive systems I had ran before in the past and those passive setups were not cheap entry level junk components, but old (good) Reference MB Quarts and Focal 130k's.
> 
> In a home stereo I agree you should probably leave the crossover alone, but in a car, no mass produced generic passive crossover is going to be able to take into account the car, the install, and whatever else effects the frequency response. Going active allows me to infinitely adjust the levels between the mid and tweeter (not just -3/0/+3db on the tweeter), to pick the frequency and slope of the crossover that best suites my system, and another big plus, is it allows me to change out drivers without having to buy or design a whole new passive crossover that may or may not work in my setup. Also, the system is cleaner over all when used bi-amped than through the passive set since the mid and tweeter are independent of each other so even if the mid amp is clipping, the tweeter amp is not.
> 
> ...


If you are using raw drivers purchased off Parts Express or Madisound, oh hell yeah, active is a million times easier.

What's baffling to me is when so many people are trashing the passive crossovers that CAME WITH their speakers.

It's like purchasing a house, then removing the foundation, because you think you can do it better.

Why bother?

The passive crossover is the foundation of any good two-way component speaker.


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## capnxtreme (Feb 5, 2008)

Also, JBL obviously has to compromise when they design a crossover to work across multiple different mounting configurations. We're generally trying to squeeze every last drop of performance out of the mounting configuration that we DO have.


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## capnxtreme (Feb 5, 2008)

ctrhenry said:


> but it is helpful information for the noobs.....no?


No, not when it completely confuses the issue and absolutely incorrectly answers the question of WHY we recommend active crossovers.


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## ehiunno (Feb 26, 2008)

Patrick Bateman said:


> It's like purchasing a house, then removing the foundation, because you think you can do it better.


No, no, no. Its not like that at all. Its like someone built a random foundation before knowing what kind of house you were going to build, and then your people showed up to build the house and it was the wrong kind of foundation. So they HAD to tear it out and put the right one in.


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## 89grand (Nov 23, 2006)

Patrick Bateman said:


> If you are using raw drivers purchased off Parts Express or Madisound, oh hell yeah, active is a million times easier.
> 
> What's baffling to me is when so many people are trashing the passive crossovers that CAME WITH their speakers.
> 
> ...


Not just with raw drivers, that's just one advantage. I'd toss the passive even if I ran a complete component set, in fact I have

Again, I suggest that no passive crossover no matter how good can compensate for every install, in every type of car. I'd be willing to bet most passives are designed to sound decent in a normal door install, but when you don't install it in the door, in the car it was modeled in, it doesn't work very well.

Active setups are better in every single regard I can think of. I see no advantage the passive crossover has except for noobs with no understanding of car audio. For them, the passive is probably good enough, but that's not what this site is all about.


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## 89grand (Nov 23, 2006)

Double post


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## ehiunno (Feb 26, 2008)

Yes. Can you tell me one benefit that a passive gives you other than cost? Assuming you have the know-how to tune an active system.

*edit*I dont mean you as in PB, just a general person.


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## digital (Sep 12, 2008)

Patrick Bateman said:


> IMHO the crossover is the most critical component in any loudspeaker.


Since active crossovers are better from passive crossovers, it makes more sense to use them.

Do you really want to redesign and (re)assemble your passive crossovers for a 3 way system, each time you change a woofer/mid/tweeter?


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## Patrick Bateman (Sep 11, 2006)

capnxtreme said:


> Also, JBL obviously has to compromise when they design a crossover to work across multiple different mounting configurations. We're generally trying to squeeze every last drop of performance out of the mounting configuration that we DO have.


But how do you do that without a mic and gated measurements?

Even an RTA isn't sufficient, because of all the reflective surfaces.

Not to get off-topic, but I think this is one of the reasons that car audio is dying. A lot of people spend thousands of dollars on their stereos, and wind up with something that's WORSE than the factory system. Back in the 80s the factory systems were crap, but nowadays, car companies are using the same tricks that I'm preaching here on the forums.

Car audio is damn near rocket-science.


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## 89grand (Nov 23, 2006)

If someone is spending thousands of dollars and their system is worse than the factory, and I'm sure you are right that some have, they need to spend a lot more time reading this site.

Even if I don't have the equipment to measure, I can still tune my system better active than a passive system can do. I trust my ears quite a bit actually.


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## ehiunno (Feb 26, 2008)

Patrick Bateman said:


> But how do you do that without a mic and gated measurements?
> 
> Even an RTA isn't sufficient, because of all the reflective surfaces.
> 
> ...


The reflective surfaces are part of the reason an RTA is useful... but if nothing else with an active, you can sit exactly where you are going to be listening to it with the drivers mounted exactly where you want them, and play with it until it sounds best to you. That takes 0 measurement equipment, but a large time commitment.


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## ehiunno (Feb 26, 2008)

89grand said:


> they need to spend a lot more time reading this site.


[sarcasm] so they can find out which sub has the best ESSS QQUUEEEE????? [\sarcasm]


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## imjustjason (Jun 26, 2006)

I was going to say they run active for time alignment, but most quality passives are bi-amp capable. Maybe it's a fit in with the crowd thing, that or they just feel it gives them greater control. 

I don't think anyone is claiming they are smarter than the manufacturer, they just know what they like better than the manufacturer.


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## 89grand (Nov 23, 2006)

ehiunno said:


> [sarcasm] so they can find out which sub has the best ESSS QQUUEEEE????? [\sarcasm]



I'm sorry, I should have said more time reading "the old posts" on this site.


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## metanium (Feb 2, 2007)

Patrick Bateman said:


> If you are using raw drivers purchased off Parts Express or Madisound, oh hell yeah, active is a million times easier.
> 
> What's baffling to me is when so many people are trashing the passive crossovers that CAME WITH their speakers.
> 
> ...


Why bother huh? It's not because it is easier, it's because you simply get much better results. Passives characteristics change with temperature, time, impedence, frequency, etc. They are affected by WAY too many variables. An active crossover gives you stability (it's not affected by these variables). You can dial in the crossover point and slope for your installation, not just some network that covers most situations, but actually dialed-in to YOUR situation.

Have you ever had a capacitor in a passive fail? I have. It cost me 2 tweeters before I determined it was the passive network. I went full-active 2-1/2 years ago and I will never use passives again.....Unless I just get lazy or no longer care about having great sound. Of course everyone has an opinion, this just happens to be mine.


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## Chaos (Oct 27, 2005)

Patrick Bateman said:


> The passive crossover is the foundation of any good two-way component speaker.


I couldn't agree more...in theory. In practice, especially among a bunch of DIY tweakmeisters like most of us here, flexibility is crucial - which naturally makes the necessity for versatility a foregone conclusion.

Then again, if you can buy a decent comp set which comes with an x-over and sounds good in your car, then yeah, I can see why you would say that it would be foolish to dispose of it in favor of active.

To each their own


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## splicer (Oct 4, 2008)

Patrick Bateman said:


> If you are using raw drivers purchased off Parts Express or Madisound, oh hell yeah, active is a million times easier.
> 
> What's baffling to me is when so many people are trashing the passive crossovers that CAME WITH their speakers.


Maybe they are just trying to be like the cool people who buy raw drivers.


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## metanium (Feb 2, 2007)

splicer said:


> Maybe they are just trying to be like the cool people who buy raw drivers.


Damn, busted! That's totally it.:stupid:


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## 89grand (Nov 23, 2006)

splicer said:


> Maybe they are just trying to be like the cool people who buy raw drivers.


Yeah because the cool thing to do is buy over priced often poor performing passive component sets. Yeah, you nailed it.


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## michaelsil1 (May 24, 2007)

I'm not going to knock any Passive System especially if you're happy with the results. I'll be the first to admit that tuning an Active System is a pain in the ass. I wouldn't have gone Active if I was happy with the Component set I bought.


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## fredridge (Jan 17, 2007)

why put an intake on your car, or custom exhaust, or suspension or anything else.

Many people are very happy with a simple system that plays and sounds decent....many factory systems are that way. 

This question is like going on a tuner forum and asking "why do performance mods?" The manufacturer knew best.

It is because most people here are looking for greater performance out of their systems.


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## David_Edwards (Nov 12, 2008)

capnxtreme said:


> No, not when it completely confuses the issue and absolutely incorrectly answers the question of WHY we recommend active crossovers.



So you are saying that a passive set up that steals power is not reason enough?


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## BigRed (Aug 12, 2007)

Keep rambling Dave  I totally understand your rambles

Look, most passives are designed for the mid/tweet to be close together. The minute you move that tweeter away, everything changes. Now I know some of you are going to say that some passives have the attenuation module built into it, but that doesn't account for what moving the tweeter does to the response

Active FTW!!


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## FoxPro5 (Feb 14, 2006)

Patrick Bateman said:


> What's baffling to me is when so many people are trashing the passive crossovers that CAME WITH their speakers.


I think your response might not be completely accurate. Lots of times, these guys already have active HU's and the ability to set up an active network. In this case, how can anyone learn about all the things you're ranting about without practicing with the active component of the car stereo experience? How many newbies have an RTA and want to sit and model like you do? It's just not realistic. 

Otherwise, I agree about the unnecessary need to dump the passive just cuz it's kewl. Some simply are better off running passives for may reasons. Not me, but some. 

Oh and I'm using active crossovers because npdang made me sign a contract when I first registered. :surprised:


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## David_Edwards (Nov 12, 2008)

BigRed said:


> Keep rambling Dave  I totally understand your rambles
> 
> Look, most passives are designed for the mid/tweet to be close together. The minute you move that tweeter away, everything changes. Now I know some of you are going to say that some passives have the attenuation module built into it, but that doesn't account for what moving the tweeter does to the response
> 
> Active FTW!!



That "ramble" came straight from Dr. B's mouth...

BTW..I noticed you are a member of Team Arc as well now too...congrats bro!


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## Genxx (Mar 18, 2007)

Because the large majority of the OG guys around here changed out drivers every other week. Much easier to have an active set-up to tune with.

Becuase the quality of most of the passve sets on the market suck.IMO

There are companies that acutal spend time on their passive set-ups and it shows. However the cost for those sets also reflects the time spent. Example Hertz Mille, Focal Be ect.

If you planned to keep your car for 10 years and never change speakers then maybe a custom passive set-up you designed or had help designing would make more sense.

However, when you get into doing custom passive set-up with top quality components you better be ready to let go of a large amount of cash if you plan on doing something like a 3-way plus sub.

There was someone on here from EMMA that had a full passive car and the cost was crazy once completed.

You could also argue that in todays market going active is not expensive and can be done really for a few hundred bucks. FRX-456 and a simple 30 band EQ easy to do.


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## captainobvious (Mar 11, 2006)

capnxtreme said:


> This couldn't be any further from the answer to the OP's question--it has absolutely nothing to do with why active is usually recommended here FOR A CAR. You're just rambling about the theoretical benefits of an active speaker system, in general. That's pretty clearly not what the OP was asking.


The question was "Why is everyone using active crossovers?"

He listed a viable reason. 

Wheres the problem?


Yes there are other reasons - adjustability, versatility and the fact that a supplied passive crossover is designed to deliver a high level of performace in a cookie cutter installation, not the BEST performance in individual and unique installations.


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## SPAZ (Jan 7, 2009)

So why not use the passive crossovers from a set and then EQ them instead of running active? At least at that point you can get away with using only one amplifier and no need to use a 3way crossover.


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## Patrick Bateman (Sep 11, 2006)

Genxx said:


> Because the large majority of the OG guys around here changed out drivers every other week. Much easier to have an active set-up to tune with.
> 
> Becuase the quality of most of the passve sets on the market suck.IMO
> 
> ...


Yeah I've noticed that half of the people on here are looking for The Next Big Thing, something that will take their stereos to "the next level."

Lately that seems to involve a lot of discussion around amplifiers and processors.

IMHO, a lot of this is market driven. I mean, there are guys on here with $3000 in amplifiers and processors. Alpine must be getting rich of customers like that.

But take a look at the cars that are sound off legends, and you seem the same thing over and over again:

- Very simple soundstage, often as little as two or four speakers up front
- These guys didn't tune their system with a Focal demo CD, they tuned it with a TEF machine or gated measurements
- The midrange octaves are all coming from the same place (IE they used waveguides or two-ways located within centimeters of the woofer.)


Just a few examples:










Gary Biggs's Buick










Harry Kimura's Legend










Buick Grand National










Earl Zausmer's car is loonier than my front stage


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## 89grand (Nov 23, 2006)

SPAZ said:


> So why not use the passive crossovers from a set and then EQ them instead of running active? At least at that point you can get away with using only one amplifier and no need to use a 3way crossover.


Because like was already mentioned in this thread, eq does not solve all the other potential issues. Going active allows you to adjust the level between the mid and tweeter, the crossover frequency, the slope, and if you are using time alignment, you can t/a all the drivers separately.

You can't do that stuff with a passive crossover.


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## MarkZ (Dec 5, 2005)

Patrick, I think you answered your own question. The response goes to **** when you put the speaker in the car. Move the speakers around a little bit, and you have a completely different response.

But you're retaining the same passive crossover through it all.

People go active primarily because of the flexibility it offers. You can adjust things to suit your vehicle, your tastes, and your installation requirements. Some component set manufacturers ALSO suggest you do the same thing -- which is why they frequently offer L-pad attenuation and phase reversal switches on their passives. The active approach not only gives you attenuation and polarity control, but ALSO xover point/slope control, as well as the possibility for delay and phase adjustment.

One other thing. Aside from the insertion loss issue that the other guy brought up, you also have better tweeter protection using active xovers. When your amps clip, a passive xover will allow the midrange harmonics to reach your tweeters. The same isn't true for the active setup.

Worst case scenario: just mimic the passive xover's parameters with your active xover.

There's really no reason NOT to go active.


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## FoxPro5 (Feb 14, 2006)

Patrick Bateman said:


> - *Very simple soundstage*, often as little as two or four speakers up front
> - These guys didn't tune their system with a Focal demo CD, *they tuned it with a TEF machine or gated measurements*


Doesn't seem simple to me. I don't even know what a TEF machine is. 

How many hours did Biggs spend on his elbows doing 4 layers of Dynamat Extreme and aiming and listening and testing and aiming and over and over. How is this "simple." It looks simple after A LOT of work. 

To me, what you're trying to do is trivialize active and promote KISS as "better." I don't agree at all. Things get complicated when your own personal level of satisfaction changes. Like they say, perfection is a moving target and I don't have a PhD in Acoustics, nor do I have thousands to just do it right the first time. I learn everything by ****ing up 2-3 times. It's necessary IMHO.


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## michaelsil1 (May 24, 2007)

FoxPro5 said:


> Doesn't seem simple to me. I don't even know what a TEF machine is.
> 
> How many hours did Biggs spend on his elbows doing 4 layers of Dynamat Extreme and aiming and listening and testing and aiming and over and over. How is this "simple." It looks simple after A LOT of work.
> 
> To me, what you're trying to do is trivialize active and promote KISS as "better." I don't agree at all. Things get complicated when your own personal level of satisfaction changes. Like they say, perfection is a moving target and I don't have a PhD in Acoustics, nor do I have thousands to just do it right the first time. I learn everything by ****ing up 2-3 times. It's necessary IMHO.


Ditto


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## ctrhenry (Jul 16, 2006)

FoxPro5 said:


> I learn everything by ****ing up 2-3 times. It's necessary IMHO.


I wish I was that efficient


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## Patrick Bateman (Sep 11, 2006)

FoxPro5 said:


> Doesn't seem simple to me. I don't even know what a TEF machine is.
> 
> How many hours did Biggs spend on his elbows doing 4 layers of Dynamat Extreme and aiming and listening and testing and aiming and over and over. How is this "simple." It looks simple after A LOT of work.
> 
> To me, what you're trying to do is trivialize active and promote KISS as "better." I don't agree at all. Things get complicated when your own personal level of satisfaction changes. Like they say, perfection is a moving target and I don't have a PhD in Acoustics, nor do I have thousands to just do it right the first time. I learn everything by ****ing up 2-3 times. It's necessary IMHO.


You really think Biggs would aim his speakers, put on a Focal demo CD, listen for ten minutes, and then repeat?

Mark Eldridge said "(TEF) has been very helpful in my learning, testing, and design/development work. To me, it has been worth much more than I paid for it."

Richard Clark literally ran out of gas, with his car parked, doing measurements.

Everything I've learned has shown that the pros don't do this by ear. So if you want a world class stereo, why are you using an active crossover that was adjusted by ear?

Mark, some questions on the TEF-20 [Archive] - CARSOUND.COM Forum


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## michaelsil1 (May 24, 2007)

Patrick Bateman said:


> You really think Biggs would aim his speakers, put on a Focal demo CD, listen for ten minutes, and then repeat?
> 
> Mark Eldridge said "(TEF) has been very helpful in my learning, testing, and design/development work. To me, it has been worth much more than I paid for it."
> 
> ...


I don't even want to think about tuning a four way active system by ear.


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## M-Dub (Nov 29, 2006)

Patrick Bateman said:


> It can take months or even years to perfect a passive crossover.


That's why


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## Genxx (Mar 18, 2007)

Patrick. Mark E. being a friend of mine and tuning my truck I am well aware of how he tunes and what he uses.

Mark can do final tuning by ear in a 4-way set-up.BTW

Scott B. can tune pretty damn awesome from ear also.

Mark has some really great stuff for tuning like the rotating mic stand.

However, if you think Marks NASCAR or 4-Runner were just some simple set-up you have a lot to learn.

Same goes with Biggs Regal. 

The dash in all three vehicles above is custom the vehicles have been heavily modified like Biggs Regal and the floor. 

Do you think Biggs and Mark are or were running passive?

He need to do some more reading before throwing up Mark or Biggs stuff and make sure you know what was in those cars and what was done exactly.

If you think you are going to get insight or knowledge into what was done to stuff like Marks 4-Runner or Biggs Regal by reading a magazine article or small blurb on the web you are crazy.


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## Patrick Bateman (Sep 11, 2006)

Genxx said:


> Patrick. Mark E. being a friend of mine and tuning my truck I am well aware of how he tunes and what he uses.


Then enlighten us.



Genxx said:


> Mark can do final tuning by ear in a 4-way set-up.BTW


Everyone does "final tuning" by ear. The problem is when your ears are all you rely on.



Genxx said:


> Scott B. can tune pretty damn awesome from ear also.


We get it, you're on a first name basis with everyone in car audio.



Genxx said:


> Mark has some really great stuff for tuning like the rotating mic stand.


I'm totally confused now. I thought you were disagreeing with me.
Now you are admitting that microphones are integral to their tuning?

Are you disagreeing with me or not?



Genxx said:


> However, if you think Marks NASCAR or 4-Runner were just some simple set-up you have a lot to learn.
> 
> Same goes with Biggs Regal.
> 
> The dash in all three vehicles above is custom the vehicles have been heavily modified like Biggs Regal and the floor.


What I wrote was "(the have a) Very simple soundstage, often as little as two or four speakers up front"

We all have a lot to learn, but sometimes the simple solution is the best solution.



Genxx said:


> Do you think Biggs and Mark are or were running passive?
> 
> He need to do some more reading before throwing up Mark or Biggs stuff and make sure you know what was in those cars and what was done exactly.
> 
> If you think you are going to get insight or knowledge into what was done to stuff like Marks 4-Runner or Biggs Regal by reading a magazine article or small blurb on the web you are crazy.


I'm glad you set me straight. All this time I've been learning from the greats was obviously time wasted. It's a good thing we have wise men like you on the forum.


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## Genxx (Mar 18, 2007)

Why so defensive? You start saying this and that about certain installs that I know something about.

I tell you are over simplifying them and now you start getting you panties in a wad.

I am sure if you want to find out how Mark tunes he will be happy to tell you or you can pay him and have him come show you how to tune or you could attend one of his seminars.

Just because you use 2 to 4 drivers does not make it a simple install or car to tune.

Marks NASCAR uses IIRC 12 drivers on the front stage + 2 subs, so that is 14 drivers.

I never said I disagreed with anything you were saying you drew that conclusion.

I think you are over simplifying things to try and prove your point. That is going to be a reach picking cars like the one's you listed. There is nothing simple about any of those cars or the front stage layout.

I know Biggs and Mark have some form of processing in both the Regal, 4-Runner and the NASCAR.

You original argument or question was "Why Is Everyone Using Active Crossovers?".

You have now changed the debate to look at how simple X front stage is because it appears you were not getting the desired response to your question.

I can tell you that the tune on my truck at Tyler, TX was all done by ear due to making a front stage speaker change that night. Scott tuned only by ear and I was happy with where I placed considering the cars I was up against. My truck has since been completely re-done to fix some speaker placement issues that I chose.

So tuning by ear can be done you do not always have to have x or x to get it done correctly.

I agree with you that having x piece of equipment is by far the preferred method.IMO


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## 89grand (Nov 23, 2006)

I'm going to be honest with you Patrick Bateman, you normally come across as pretty intelligent, at least when it comes to wave guides and all that, but you're out in left field in this thread.

Are you just looking for an argument, or have you focused so much on wave guides that you don't understand anything else?


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## James Bang (Jul 25, 2007)

From passive vs. active

to ears vs measurement equip/tools


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## ehiunno (Feb 26, 2008)

Patrick,

I am going to give you the benefit of the doubt, in that you came from the home audio world where passive crossovers are king and there is little reason to use anything else. (especially since 75% of home audio people think that you need a $1000 5 watt amp for good sound, so having to have 3 of them would get espensive... *eye roll at home audophiles*)

But really, take the time to reply to the points brought up against passive crossover, and maybe we can have a real discussion, but I dont see you doing that. Only talking about tuning equipment and only listening to people that back you up...


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## Fast1one (Apr 6, 2007)

Patrick, why are you assuming that people who use active crossovers DON'T use measuring equipment? I don't quite understand the connection...


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## Oliver (Jun 25, 2007)

I use active because the passives just sound to good. with active , I can make it sound ****ty easier.


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## BigRed (Aug 12, 2007)

The simple answer to your question is "NO!! Not EVERYBODY is using active"

Does that help? 

Your question is false, therefore it cannot be answered correctly


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## michaelsil1 (May 24, 2007)

a$$hole said:


> I use active because the passives just sound to good. with active , I can make it sound ****ty easier.


I believe that is the point the OP was trying to make.


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## VP Electricity (Apr 11, 2009)

Not sure why such a simple topic went into the ditch so badly...



Patrick Bateman said:


> People on here are frequently recommending that active crossovers should be used in lieu of the passive crossovers which come with their component speakers.
> 
> I know that car audio installers routinely recommend this because it's an easy way to sell two extra amps and a crossover. But if you're doing it yourself, what's the point?


Most pro installers I know don't - they would rather hook up a bigger 2-channel than a medium 4-channel and have to run another set of wires into the doors, then tune. 




Patrick Bateman said:


> P IMHO the crossover is the most critical component in any loudspeaker. It can take months or even years to perfect a passive crossover.


Yes, but so few passives approach perfection. Component count, quality, and size are a huge influence over final production design. 

I regularly have made simple passives for the 2W mid-tweet handoff using better components (air core, heavier gauge, better caps, wire wound resistors) and measuring Z (looking for Zmax, then deciding F3, then measuring Z at that F3, then calculating component values) and regularly get better sounding results than with factory crossovers (even Dynaudio). But it takes some time and _some _T&E. 

When I first came to DIYMA, I expected passives to get some love. But I was surprised to see such open contempt for a technology that can sound great. 

My takeaway I get on the subject is that passives can sound fine, but amp channels are so cheap now, active crossovers so common (and time alignment so common - which requires dedicated driver channels), and measuring Z can be such a PITA, that no one wants to do the final experimenting any more. It seems to be convenience, largely. 

That said, my next system will be my first all-active system in 20+ years.


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## Patrick Bateman (Sep 11, 2006)

Genxx said:


> Why so defensive? You start saying this and that about certain installs that I know something about.
> 
> I tell you are over simplifying them and now you start getting you panties in a wad.
> 
> ...


Yeah we got off topic

The thing that makes me crazy is when people buy an expensive components set, and then discard the crossover. THAT's what makes me crazy.


If you are buying woofers and tweeters from Parts Express or Madisound, by all means, go active. It's easier.

If your component speakers are inexpensive, they probably have a sub-par passive, and an active might work better. For instance, if I bought a component set and the whole crossover was a single capacitor.

And yes, even with a very expensive set of components you may be able to wring another 10% out of them using an active crossover and a LOT of measuring and tuning.

Again, my main gripe is when people are just telling anyone and everyone on here to ditch their passive crossovers. Someone in this very thread literally said "there's no reason NOT to go active."

That's silly. There's tons of reasons not to go active:


Expensive components have complex crossovers that work quite well, right out of the box. I've seen components speakers with 15 element crossovers.

Expensive components often give you the option of adjusting levels passively.

And the biggest reason of all, is that it's really easy to completely screw up a decent system with a bad crossover and time delay.


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## Patrick Bateman (Sep 11, 2006)

89grand said:


> I'm going to be honest with you Patrick Bateman, you normally come across as pretty intelligent, at least when it comes to wave guides and all that, but you're out in left field in this thread.
> 
> Are you just looking for an argument, or have you focused so much on wave guides that you don't understand anything else?


Actually I've always been a car audio guy. I got into horns in the early 90s, when they were dominating the sound off scene. At the same time I developed an interest in bandpass subwoofers, because they were big at the same time.

It was until 2006 that I had that "Eureka" moment and realized that horns, waveguides, and bandpass subwoofers are all the same thing. They are all variations on a front loaded horn.

















​
In the pictures above, you can see they all share a common design. A sealed rear chamber, a vented front chamber, and a duct. Change the dimensions of the duct and you have a horn or a waveguide. All three designs share a common lineage, and they work at any frequency. IE, a bandpass enclosure can be used on a midrange or even a tweeter.

I studied Geddes a lot, who was working in car audio at Ford at the time. He wrote a number of papers on bandpass subwoofers, and basically wrote the book on waveguides.

A lot of these guys have worked outside of home audio; for instance the guy that invented the Unity horn worked at Nasa years ago.


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## WRX/Z28 (Feb 21, 2008)

I think the point he's trying to make is that in a properly designed passive system, ditching the passive crossover for active may not always yeild positive results, and some times can yeild negative ones. Too many people on here think Active = Automatically better. 

If you can't tune the set better than the OEM, you may be doing yourself a disservice by ditching their hard work into designing a passive, especially if it means you have to purchase more equipment (IE amp channels, different processing, more wiring)

Before all you "active" nazi's flame me, take note of the use of the word "may".


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## VP Electricity (Apr 11, 2009)

Patrick Bateman said:


> The thing that makes me crazy is when people buy an expensive components set, and then discard the crossover. THAT's what makes me crazy.
> [/list]


I wish I could say that I thought the passive xover quality was always as high as the drivers. With some speakers, like the Alpine SPX-F13M and 17M, the passive was probably better. With Morel Elates, they are very good. 

With Dynes, with many asian kits, the passives are not up to the design levels of the drivers.



Patrick Bateman said:


> And the biggest reason of all, is that it's really easy to completely screw up a decent system with a bad crossover and time delay.


This is very true. But even I, a passive apologist, has to say, AFTER you screw it all up, then you just turn the knob back the other way to fix it. You don't have to build new passives or try different resistors or capacitors or such. 

Again, convenience (especially for DIY-ers). 

I remember when I priced out a project I was considering - simple D'Appolito towers with Dyne drivers back when you could get them. I planned on using very good passive components. Well, the passive component cost was well over the cost of the Dynes! I scaled things back... 

I will certainly agree that the new way doesn't build character...


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## MarkZ (Dec 5, 2005)

Patrick Bateman said:


> Again, my main gripe is when people are just telling anyone and everyone on here to ditch their passive crossovers. Someone in this very thread literally said "there's no reason NOT to go active."
> 
> That's silly. There's tons of reasons not to go active:
> 
> ...


Yep, that was me who said that.

When I said that, though, I was making the assumption that competence was involved. Otherwise, I would agree with you -- someone who doesn't know what they are doing should be involved in as few decisions as possible.

But I completely disagree with your "work quite well right out of the box" assertion. How do you reconcile that stance with your EARLIER statement about frequency response being so incredibly dependent on vehicle, aiming, head position, etc?

That's the answer to why passive crossovers "out of the box" are nonideal in the car. That doesn't mean you can't design one to work great in a specific install. But unless the manufacturer says something like "we designed this passive in a 2007 Malibu with the speakers mounted in the factory locations and at this particular seat position", there's no way you can expect "lab performance" from them in your car.

And like I said earlier, you can almost completely mimic a passive crossover actively. If the passive xover has a LP crossover point of 2.5kHz 12dB/oct and a HP of 3kHz 12dB/oct polarity-reversed, then use those settings in your active crossover. That was what I meant when I said there's no downside to using an active arrangement.


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## ctrhenry (Jul 16, 2006)

great, now i have to go read the waveguide threads again............


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## M-Dub (Nov 29, 2006)

Patrick Bateman said:


> The thing that makes me crazy is when people buy an expensive components set, and then discard the crossover. THAT's what makes me crazy.


I don’t even know what my Profi Kicks even sound like with the passives. It was cheaper to get everything as a package deal, so I just gave my passives to the hobos.

I guess that makes you crazy huh?


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## Patrick Bateman (Sep 11, 2006)

MarkZ said:


> And like I said earlier, you can almost completely mimic a passive crossover actively. If the passive xover has a LP crossover point of 2.5kHz 12dB/oct and a HP of 3kHz 12dB/oct polarity-reversed, then use those settings in your active crossover. That was what I meant when I said there's no downside to using an active arrangement.


Actually there's a very subtle reason that won't work -

Let's say you have a passive crossover with a 2.5khz 12db/oct low pass. And you want to go active, so you dial in an identical low pass with an active xover. If the passive doesn't have a zobel, the active will have a steeper slope than the passive.

It's a subtle difference, but it could lead to a dip or peak of 3db around the xover point, which would be audible.


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## Patrick Bateman (Sep 11, 2006)

WRX/Z28 said:


> I think the point he's trying to make is that in a properly designed passive system, ditching the passive crossover for active may not always yeild positive results, and some times can yeild negative ones. Too many people on here think Active = Automatically better.
> 
> If you can't tune the set better than the OEM, you may be doing yourself a disservice by ditching their hard work into designing a passive, especially if it means you have to purchase more equipment (IE amp channels, different processing, more wiring)
> 
> Before all you "active" nazi's flame me, take note of the use of the word "may".


THIS

You summed it up better than I could:

"in a properly designed passive system, ditching the passive crossover for active may not always yeild positive results, and some times can yeild negative ones. Too many people on here think Active = Automatically better."


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## MarkZ (Dec 5, 2005)

Patrick Bateman said:


> Actually there's a very subtle reason that won't work -
> 
> Let's say you have a passive crossover with a 2.5khz 12db/oct low pass. And you want to go active, so you dial in an identical low pass with an active xover. If the passive doesn't have a zobel, the active will have a steeper slope than the passive.
> 
> It's a subtle difference, but it could lead to a dip or peak of 3db around the xover point, which would be audible.


Sure, that's why I said "almost". But you'll still get pretty close. Zobels are VERY imperfect circuits. Mostly because the RLC parameters of the loudspeaker are dynamic, so it's impossible to compensate for them correctly. So, the "2.5kHz 12dB/oct" crossover point I mentioned earlier won't remain 2.5kHz all the time anyway. As a result, the alignment of the filters will be warped, which impacts not only the slope but the xover point.

Such problems don't occur with active filtering, because active filters are not impedance-dependent.


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## LondonRS4 (Jul 16, 2009)

I can't believe people are having this discussion ! If you have the mathematical tools and DSP power, active beats passive any day of the year. I can show you a 6" midrange that produces a flat response from 30 Hz to 20kHz with DSP preprocessing. All you do is measure the response of the speaker with pink noise, throw that into the Matlab DSP toolbox and out comes a pre-emphasis formula that will get you a flat response. HOWEVER, this has some problems.

(1) The volume you can do this at is very low. Because the efficiency of the driver is not great at high and low frequencies. So you may need 35 dB boost to get the same SPL at 30 Hz as the driver can produce at 2 kHz. And likewise at 20 kHz. That means you lose 35 dB in dynamic range in order to get the SPL equalized across the spectrum.

(2) Flat response does not imply distortion free. You can make a mechanical system resonate at any frequency, but it will produce all kinds of modes and harmonic distortion in the process. So it will sound like crap even if it does respond "flat".

So generally (or practically), you pick 3 radiators, optimized for 3 bands, and try to stick them together. That keeps efficiency up and THD down. In a home audio system, the speaker's frequency response is pretty independent of the room unless you stick it in a corner. So a passive system works reasonably as you are dealing with a free space solution. In a car, that ain't true. So a passive is a "best approximation" but is only valid for a free space solution, not the car you are in. You could certainly build passive crossovers that did the job if you measured all your radiators' frequency responses in-situ. It wouldn't be as good as DSP, but it could work.

The final point is that time alignment is much more important in the car as the speakers are all over the place. You can have a flat response, and you can have no distortion, but if the signals don't add constructively at your ear, then psychophysically you don't respond well to that. The sound is "muddy". At home you sit in the far field of the speakers and the sound from all the radiators gets to you at the same time (not tru for 5.1 or 7.1 but let's stick to stereo). In the car you are in the near field. Time alignment is critical in the near field.

So Audyssey gets time alignment and frequency response in one shot using a Chirp pulse. The amplitude and phase of the received signal as a function of frequency is all you need to get time and equalization correct. *Passive crossovers can never do that.* They can give you a flat response but they can't advance or delay time (or equivalently phase) (at least not in a nicely controllable manner).

I have Mission Audio Gold Series RS6's at home. They have crossovers, but they can also be bi-amped (mids/base + tweeters). I use the crossovers, but I can tell you that the Audyssey on my NAD T785 is doing some gymnastics to get the room response of the speaker to be flat and phase coherent. So a good rule of thumb for home audio is to let the passive crossovers take out the greatest part of the variance, and then let the DSP do the rest.

In a car, I don't know yet, but I will experiment. My sense is the environment is so much more complicated that you might just want to let DSP do all the work to get amplitude and phase all sorted out. What you don't want is the DSP having to fight the crossover, because that just costs you headroom.


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## WRX/Z28 (Feb 21, 2008)

Patrick Bateman said:


> THIS
> 
> You summed it up better than I could:
> 
> "in a properly designed passive system, ditching the passive crossover for active may not always yeild positive results, and some times can yeild negative ones. Too many people on here think Active = Automatically better."


Eh, the "active" nazi's will not buy this. So many on here are of the oppinion that there is only one way to skin a cat. People will cite FR problems that need to be corrected, but as you pointed out, inches of driver placement change can completely skew these results. 

The part I'd like to add is that driver listening position can skew these results too! Slouch down in your seat a little because you are tired? Different FR. Put a shorter person in the drivers seat, different FR. Slide you seat back or forward one notch, different FR. 

Who's to say that you can't compensate for any FR oddities with a good eq just as well as you could with active crossovers? 

Also as so many have pointed out, since when does a ruler flat FR sound good? 

I'd like someone to point out a passive component set with a big FR flaw in a standard install. One they've measured, and corrected with active crossovers in a way that they couldn't correct it with eq. Until then, it's all hearsay.


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## MarkZ (Dec 5, 2005)

WRX/Z28 said:


> I'd like someone to point out a passive component set with a big FR flaw in a standard install. One they've measured, and corrected with active crossovers in a way that they couldn't correct it with eq. Until then, it's all hearsay.


I had a Morel 3-way set that exhibited a sizable peak somewhere around 1kHz, and a trough at around the woofer/mid xover point. I mostly attributed it to the passive crossover, and changed crossover points considerably and boosted the woofer's level in order to fix the problem.

Was it a standard install? I dunno. They were mounted rather low in the door in a pretty unorthodox arrangement, I guess. I can dig up pictures if you're interested.

Anyway, this was a case where the passive crossover didn't suit my needs. I also wasn't thrilled with the fact that most of the midrange energy was being handled by the woofer. It didn't really hurt in my particular case, since the drivers were coincident, but in a dash install I could see that being an issue.

I'm also pretty convinced there was a region of high distortion in the upper midrange, but the impedance/sensitivity profile of the dome mid wasn't adequately filtering it out (the circuit for the midrange didn't have a LPF). I have no evidence for that, as I never measured it. Just a hunch.

Anyway, it's an example where I really liked the drivers but hated the crossover. In a different environment, the crossover may have been fine. But maybe not.

You're right about EQing though. But it comes with its own set of problems that, in many cases, can be fixed more "cleanly" (for lack of a better term) with active crossover/level controls or by modifying the existing passive xover. Really, modifying a passive is always an option, so it's not really the demon seed we're making it out to be. It's still a ***** though, at least in comparison to turning a knob.


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## thehatedguy (May 4, 2007)

Passives in the car is a lost art form. Back in the day in the lower power classes in IASCA it was common to find very complex passive systems. EMMA in Europe up until last year had a class that was a pure passive class. IMO, a passive system dialed in is very sweet and has a certain sound not found in active systems. But...to do a passive system right it takes money- lots of it, time- lots of it, and equipment. And there is probably a basic lack of understanding on exactly how to build something complex like that containing all of your EQ and crossover functions. 

And another and, not too many people know how to do time alignment with a passive network. Time alignment these days is more important to the general masses because nearly everyone is wanting to build a one seat wonder. So that means you have 36 different delays you need to do. Back in the day with a 2 seat car some of that need for delays was minimized with proper PLDs and speaker locations...but delay could tweak it even more.

Also equipment to do the measurements used to be ungodly expensive. A TEF20 was what, $8000? Now you can get a laptop, a sound card, some good mics, and some very nice inexpensive software and do more than a TEF could at a 1/10th of the price or lower.


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## Vega-LE (Feb 22, 2009)

All I have to say is, if you're going to go passive go with ones that are bi-amp capable.


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## 89grand (Nov 23, 2006)

Screw passive crossovers. I have no use for them.


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## Chaos (Oct 27, 2005)

thehatedguy said:


> Passives in the car is a lost art form. Back in the day in the lower power classes in IASCA it was common to find very complex passive systems.


truf. 

That's a good point. I'm not saying that it's for everyone, and I'm not saying that it's easy, but it can be done IF you are willing to go through the painstaking process of creating an effective passive network.

These days, active processing is much more readily available, and therefore becoming more prevalant for two reasons: it is affordable, and it works. 

In theory, I have no qualms against using passives, but given the environment we are working with, using pre-fabs will always be a compromise.


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## WRX/Z28 (Feb 21, 2008)

Chaos said:


> truf.
> 
> That's a good point. I'm not saying that it's for everyone, and I'm not saying that it's easy, but it can be done IF you are willing to go through the painstaking process of creating an effective passive network.
> 
> ...


See, this is the part I disagree with. I don't think it's "always" a compromise. 

Don't get me wrong, I think active has it's place. Using proper measurements, and raw drivers can yeild some positive results, but all you guys that are under the impression that active yeilds some "magic voodoo" on your system that makes it unequivocally better are mistaken. 

Passives have become the enemy, and unjustly so. Some of the best cars I have had the pleasure of auditioning had passive networks in place. Having heard these cars, I find it hard to beleive that changing those cars to active would have made them any better. In fact, I'd bet that it could take months of tweaking and tuning before the car sounded nearly as good. 

Back in the day, I went as far as to utilize a 2 channel amp to run my front speakers, and sub. This was thanks to the use of a passive crossover. That setup sounded incredibly good. People today would be confused as to how 2 channels could possibly run a sub and front speakers simultaneously. 

I just don't get it... I know for a fact that all of you have heard passive cars that sounded incredible to you. Why now does everyone bash passive's?

I have a theory. It allows us to feel superior, like we know some great secret that others have yet to discover. It's like a badge of honor, or a "claim to fame" that allows us to feel "elite". 

Again, you guys that feel that one solution is right for every person, and every situation. You couldn't be further from the truth.


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## Foglght (Aug 2, 2007)

WRX/Z28 said:


> I just don't get it... I know for a fact that all of you have heard passive cars that sounded incredible to you. Why now does everyone bash passive's?
> 
> I have a theory. It allows us to feel superior, like we know some great secret that others have yet to discover. It's like a badge of honor, or a "claim to fame" that allows us to feel "elite".
> 
> Again, you guys that feel that one solution is right for every person, and every situation. You couldn't be further from the truth.


I really haven't heard anything passive that sounds spectacular. 

I think its pretty simple with regard to this site. Most of everyone here is trying to learn a little bit more than the average joe because its interesting. In the quest, we find that these raw drivers from madisound and the like can be bought as a separate set, instead of paying through the nose for a whole passive network. Swapping in a Peerless SLS 6.5" where a Diamond D661 used to be using the same x-over won't work very well, and will probably sound like butt. 

That's where you start to learn what speaker specs do. Again, for some reason, people on this site fail to see that most people have no idea what most of this stuff means, including the newbs that come to this site. I didn't know when I first arrived. Its complicated, and rough at first. Gets even tougher when you understand the basics and want to get more advanced with it. 

Back to active x-overs. 

The experimentation stage starts. One could design their own passive x-over for each set, but why do that, when we can easily get a nice processor that can set the slopes and x-over points where we know the driver should work pretty well?

I don't think my system is any showstopper, but I think it sounds pretty damn good, and I have an active 4-way setup. Yeah, I spent about 100 hours tuning the damn thing, but I learned a whole hell of a lot by doing it, and it was fun......but also frustrating. 

So to make it simple, to try the raw drivers and have the ability to change things up to your liking, or to the driver specs, the active x-over is the easiest way to accomplish that. Buying pre-boxed sets is not what this site is about. For anyone else I know, other than myself, I'd throw a passive set in. I wouldn't even bother trying to explain to someone why I would do something different than buy a pre-box set.


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## M-Dub (Nov 29, 2006)

It’s all about superior technology.

Were all talking about the same things here, resistors, capacitors, and inductors.

Active crossovers use the same components as their passive counterparts, but they are much smaller, and variable.

Active crossovers also filter the signal before amplification allowing the overall system to be more efficient. Whereas passives filter the amplified signal and dissipate it as heat energy.

Passives are just old school, like tubes, chop sticks, and the abacus. We just found a better way to do it is all.


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## 14642 (May 19, 2008)

Although the OP's question pertains only to crossovers, neither active nor passive crossovers are adequate to tune the response in any car. An equalizer is required. 

The benefits of active are that the circuit can be designed to do a little EQ by choosing non-standard alignments to smooth the transition. Does this change depending on mounting location? Sure. That happens whether you're using active or passive. A simple active crossover provides a range of adjustability that most passives don't, but the passive provides this opportunity to choose non-standard alignments that the aactive crossover doesn't. One is not necessarily better than the other.

As far as insertion loss goes, it's almost a moot point, no matter which doctor mouth is spewing the info. Any passive worth its salt has a DCR that's low enough not to matter. Varying the impedance is how a passive network works and the impedance within the crossover region is NOT parasitic resistance. 

Actives do relieve the amplifier from reproducing information that will never make it to the speaker, and that may be helpful in terms of available output power.

Finally, I know exactly how both Gary Biggs and Mark Eldridge tune their cars. Both cars sound great. They also sound very different. I can say, for certain, that all of this nonsense about aiming mids and midbass drivers can be eliminated with a proper understanding of dispersion, bandwidth and filtering. It's very simple. Use the speakers within their piston range, and aiming isn't necessary. This is the benefit of a three-way system, especially when a 6" or larger midrange/midbass will be used. 

I've never seen anyone rebuild their dashboard and determine a shape bsed on anything scientific or on any frequency response measurements that confirm the new shape's appropriateness or anything of the sort. It's usually to "prove" some hairbrained hypothesis and rarely makes an improvement significant enough to justify the time and expense. 

One is not better or worse than the other. They're just different.


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## M-Dub (Nov 29, 2006)

Andy Wehmeyer said:


> The benefits of active are that the circuit can be designed to do a little EQ by choosing non-standard alignments to smooth the transition.
> ...
> but the passive provides this opportunity to choose non-standard alignments that the aactive crossover doesn't.


I'm not understanding this.

Can you elaborate please?


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## 14642 (May 19, 2008)

Megalo said:


> I'm not understanding this.
> 
> Can you elaborate please?


I don't know of any active network available for use in cars by aftermarket iinstallers that include a variable Q adjustment. That can be useful in helping the woofer "reach" the tweeter and in taming the hump near resonance you'll find in many tweeters.


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## Chaos (Oct 27, 2005)

WRX/Z28 said:


> See, this is the part I disagree with. I don't think it's "always" a compromise.
> 
> Don't get me wrong, I think active has it's place. Using proper measurements, and raw drivers can yeild some positive results, but all you guys that are under the impression that active yeilds some "magic voodoo" on your system that makes it unequivocally better are mistaken.
> 
> ...


Perhaps I didn't make myself clear - in fact, I agree with you for the most part.

What I said was, using *pre-fabs* would always be a compromise. Unless you, or I, or anyone, is extremely fortunate, any pre-fab passive is not likely to achieve optimum performance in any random vehicle right out of the box.

To beat a dead horse: I myself have used a simple two channel amp to run front speakers & a sub, and passive x-overs is what made it possible at the time. In that case the simple approach yielded decent results, but being inclined to tweak as I am, I always wondered if it could have been better. I didn't bother because the expense of time & money it would take to change the passives just wasn't worth it. It wasn't a good value. Now, if I can buy a processor that will allow me to simply turn a knob to vary the freq & slope characteristics of the x-over, that is an investment that has lasting value. 

Personally, I am not suffering from any delusions of magical results inherent to an active configuration, and I never said I was. Likewise, I don't have anything against passives ion general, and I have said as much already.

Futhermore, I would agree that you do have a point about the typical philosophy propagated by many members here, and rightly so - this is a clique, and diy autosound is what we enjoy discussing. Of course we are going to favor that approach, and active set-ups give us endless fodder for our topics.

Finally, I don't think it is fair to say that everybody here is of the same mind on the subject, and that we as a group are so resolute and stubborn as you suggest. It isn't a matter of truth, or of one particular methodology being "right" for everybody - the whole point is that each system is unique, and has to be tuned accordingly. In the end, it doesn't matter how you go about doing it, as long as the result is favorable. 

No amount of money, or narrow minded subjective convictions, are guaranteed to deliver the best possible sound. I would be surprised if anybody here actually subscribed to such nonsense.


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## ehiunno (Feb 26, 2008)

Megalo said:


> I'm not understanding this.
> 
> Can you elaborate please?


I think he means that most active crossovers have only a few alignments you can choose. LR1,2,3 or 4, and Butterworth 1,2,3,4 is often all they offer. You can use esoteric crossovers in a passive.

But then again, thats not true of many active crossovers. For example, mine can do almost anything. But mine is a computer, so its kind of cheating.

edit: andy beat me to it.


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## Foglght (Aug 2, 2007)

Andy Wehmeyer said:


> I don't know of any active network available for use in cars by aftermarket iinstallers that include a variable Q adjustment. That can be useful in helping the woofer "reach" the tweeter and in taming the hump near resonance you'll find in many tweeters.


Easy solution......don't use the tweeter in that range?

The Fs of many of the tweets I've used are in the 1,500-2,500 region. Not sure if I've ever used them below 4k, and usually end up with them in the 5-7k region so I can use the rolloff to compensate for sibilance. Super easy with an active x-over.


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## 14642 (May 19, 2008)

Foglght said:


> Easy solution......don't use the tweeter in that range?
> 
> The Fs of many of the tweets I've used are in the 1,500-2,500 region. Not sure if I've ever used them below 4k, and usually end up with them in the 5-7k region so I can use the rolloff to compensate for sibilance. Super easy with an active x-over.


Not so easy in a 2-way, especially with a 6" woofer. In a 3-way, I agree.


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## Foglght (Aug 2, 2007)

Andy Wehmeyer said:


> Not so easy in a 2-way, especially with a 6" woofer. In a 3-way, I agree.


Ok, then in 2-way, adjust x-over to slope gradually away from the hump with like a 6db slope, starting just above the start of the resonance?

Just throwin stuff out there, because these options aren't really available with passives, unless you build them yourself. And I know you are personally capable of that, though I am not at the moment.


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## MarkZ (Dec 5, 2005)

ehiunno said:


> I think he means that most active crossovers have only a few alignments you can choose. LR1,2,3 or 4, and Butterworth 1,2,3,4 is often all they offer. You can use esoteric crossovers in a passive.
> 
> But then again, thats not true of many active crossovers. For example, mine can do almost anything. But mine is a computer, so its kind of cheating.
> 
> edit: andy beat me to it.


There's no reason you can't perform the same sorts of tweaks with your active xover that you could with your passive xover. In fact, it should be cheaper and easier since there are no inductors involved in a sallen-key design.

Again, I'm not seeing any advantage with passive crossovers that you couldn't achieve in the same way with active crossovers. Unless you're talking about the impedance-dependent variability of the passive network + speaker, but I'm not sure I understand how that's a positive thing.


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## Genxx (Mar 18, 2007)

Andy Wehmeyer said:


> I can say, for certain, that all of this nonsense about aiming mids and midbass drivers can be eliminated with a proper understanding of dispersion, bandwidth and filtering. It's very simple. Use the speakers within their piston range, and aiming isn't necessary. This is the benefit of a three-way system, especially when a 6" or larger midrange/midbass will be used.


Are you saying that aiming is not important at all. Are you saying that you can get the same sound out of a driver any where it is place in the vehicle or aimed in the vehicle.

You say dispersion but does that not go back to having to aim the driver based on dispersion.

Please explain because I know I am missing something you are trying to say.


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## LondonRS4 (Jul 16, 2009)

Anything that can be done passively can be done mathematically in a DSP. Anything. Not everything done in DSP can be done in discrete component device like a crossover.

There is an art to doing a passive crossover that only a few people still know and practice. That has to be very rewarding. Any undergrad who has taken a signal processing course can produce any sound you want with very little effort in DSP. Yeah, that's not very rewarding, but it allows you to get back to spend more time listening to music and less time fiddling.

Many of us like to fiddle. That's why we are here. Old school fiddling is full of resistors, capacitors and inductors. New School fiddling is all about the DSP.

I have an Omega mechanical automatic watch, I have a Triumph Thruxton with 2 carbs. The Omega cost 4 grand, and a 10 dollar Timex keeps better time. The Thruxton requires me to adjust the mixture screws spring and fall. People wave at me every day. Both put a smile on my face.

My Audi RS4 will blow the doors off virtually anything in existence. Other than modding the stereo, there's not much else I can do with it. It uses computers everywhere to extract more hp out of a liter than virtually any other normally aspirated vehicle. This could never have been done with passive components with the kind of efficiency that this car has (yeah, 23 mpg on the highway ain't great, but a '67 charger with the same hp got 8 mpg). So instead of fiddling, I spend more time driving it. That also puts a big smile to my face.

If you ignore new technology, you get left behind. That's a fact. But you may not care. The whole point of all our toys is to enjoy.

Different strokes for different folks.


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## 14642 (May 19, 2008)

LondonRS4 said:


> Anything that can be done passively can be done mathematically in a DSP. Anything. Not everything done in DSP can be done in discrete component device like a crossover.
> 
> There is an art to doing a passive crossover that only a few people still know and practice. That has to be very rewarding. Any undergrad who has taken a signal processing course can produce any sound you want with very little effort in DSP. Yeah, that's not very rewarding, but it allows you to get back to spend more time listening to music and less time fiddling.
> 
> ...


All of this is true, and I agree with most of it. However, knowing how to write Matlab or C++ doesn't qualify one to tune anything. Knowing how to tune AND knowing how to write code is damn useful.


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## MarkZ (Dec 5, 2005)

FWIW, Matlab is very inefficient when it comes to real-time processing. They attempted to do this with their Simulink package (which sort of mimics LabView), but I think programming VST modules would be a better use of time, IMO. I remember setting up a Simulink "circuit" a couple years back just to do simple filtering, and it pinned the CPU.

However, Matlab can be useful for transcoding audio files offline. I'm gonna work on trying to do some "center" separation with it pretty soon, if I can find reference to an algorithm that I like. I'm still trying to figure that out.

But anyway, there are enough DSP options out there now to really allow us to do most of the things we need to do in audio, and cheaply, without having to code it ourselves.


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## 14642 (May 19, 2008)

MarkZ said:


> FWIW, Matlab is very inefficient when it comes to real-time processing. They attempted to do this with their Simulink package (which sort of mimics LabView), but I think programming VST modules would be a better use of time, IMO. I remember setting up a Simulink "circuit" a couple years back just to do simple filtering, and it pinned the CPU.
> 
> However, Matlab can be useful for transcoding audio files offline. I'm gonna work on trying to do some "center" separation with it pretty soon, if I can find reference to an algorithm that I like. I'm still trying to figure that out.
> 
> But anyway, there are enough DSP options out there now to really allow us to do most of the things we need to do in audio, and cheaply, without having to code it ourselves.


Yup. VST is the way to go, especially for verification.


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## Patrick Bateman (Sep 11, 2006)

Genxx said:


> Are you saying that aiming is not important at all. Are you saying that you can get the same sound out of a driver any where it is place in the vehicle or aimed in the vehicle.
> 
> You say dispersion but does that not go back to having to aim the driver based on dispersion.
> 
> Please explain because I know I am missing something you are trying to say.


Andy said that aiming _midranges and midbasses_ is pointless. And generally that is true. All speakers "beam" at a predictable frequency, based on the diameter of the cone.

If you are running a midrange or midbass so high that it is beaming, it's going to sound "thin" due to the narrowing directivity.

Also, interaural time delays dominate our hearing mechanism at low frequencies. WHERE you locate a midrange or midbass is more important than how it's aimed.

Check out some of my posts, I've explored this in a few threads.

I am also digging into the subject on diyaudio:

diyAudio Forums - Creating a Soundstage with Waveguides and Psychoacoustics - Page 1


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## Genxx (Mar 18, 2007)

Patrick-I understand what he is saying and you are saying.

I just felt Andy's statement was a little to generalized and wanted him to expand on what he said.

IMO You cannot just place a midbass or midrange any where in a vehicle and get the desired response. That to me is what it sounds like Andy's statement is saying which will lead some of the new folk around here to that conclusion.

That's why I wanted him to expand on what he said.


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## Patrick Bateman (Sep 11, 2006)

Genxx said:


> Patrick-I understand what he is saying and you are saying.
> 
> I just felt Andy's statement was a little to generalized and wanted him to expand on what he said.
> 
> ...


While it's true you can't place a midbass or midrange "anywhere", it's direction is irrelevant for most of the passband. Which is what he was alluding to when he said "all of this nonsense about aiming mids and midbass drivers can be eliminated with a proper understanding of dispersion, bandwidth and filtering."

To illustrate this point, here's the on and off-axis response of a six and a half inch woofer. It has no directivity below 1500hz.



















So you can point it up, down, left, right, even backwards.

Andy always gives me ideas for my own stereo. Maybe I will install my waveguides BACKWARDS, and fire them right into the firewall of the car. That will push back the pathlength by half a foot, and below 1700hz, the waveguide's direction won't matter.


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## 14642 (May 19, 2008)

Placement and aiming aren't the same, and I certainly didn't intend to lead anyone to believe that placement isn't important. It is, but how important depends on the rest of the tools you have to work with and whether you need the car to image in both front seats. 

Patrick is right about the aiming thing and that's what I was intending to suggest. Use the speaker in a range of frequencies where the dispersion is wide and precisely pointing the speaker at the listener isn't necessary. Tweeters ought to be aimed, because in cars there typically isn't room on the mounting surface for waveguides. If it's a custom installation and you can design an appropriate waveguide, the benefits are big. Or...you could buy a component set that includes a waveguide for the tweeter .

Even with tweeters, the laser-pointer method is nonsense--unless you're using a 3" dome and plan to strap your head to the headrest.

I find the best solution is a 3-way in the door, tweeters in the sail panels, a big center channel and some kind of processing to extract the center information if 2-seat imaging is necessary. If only one seat imaging is necessary, a 3-way in each door and delay works fine. If only one seat has to be optimized and you want to go nuts (and have someone who loves to write cool code and is an accomplished inventor) the 3-way in each door, a center channel and a processor that uses some crosstalk cancellation and adds early and late reflections is lots of fun. That's what I have currently, but I'm lucky.


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## thehatedguy (May 4, 2007)

Andy, how do Mark and Gary tune differently from a subjective point of view? Been a couple of years since I heard the Regal and probably 7 since I heard the 4 Runner.


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## 14642 (May 19, 2008)

Those are trade secrets and it wouldn't be fair of me to tell you guys how they do it. The two methods are very different, though. You'll have to ask them. I'm happy to tell you how I do it.


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## 03blueSI (Feb 5, 2006)

Andy Wehmeyer said:


> Those are trade secrets and it wouldn't be fair of me to tell you guys how they do it. The two methods are very different, though. You'll have to ask them. I'm happy to tell you how I do it.


OK Andy, how do you tune?


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## chemid51 (May 7, 2009)

test


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## guitarsail (Oct 12, 2007)

/\ Fail..


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## 8675309 (Jan 8, 2007)

C-O-N-T-R-O-L


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## thehatedguy (May 4, 2007)

I wasn't really asking how they tuned the cars, but how each sounded after tuning. What does Mark's tastes run to versus Gary's.

But how do you tune?


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## donkeypunch22 (Nov 5, 2008)

03blueSI said:


> OK Andy, how do you tune?


I asked Andy before, and this was his response:

Re: Tuning question for Andy W. or anyone that wants to chime in...
Hey DonkeyPunch,

The order depends on the tools you have to work with--well...somewhat. I'll assume you have time alignment and also assume that you're not using any matrix processing--like Dolby PL2. 

Un-EQ is really important if you'll be using matrix surround processing because those processors use phase to determine front and rear steering. Ordinary frequency-domain-only Un-EQ won't do because many OE systems use some time alignment in the factory amp. Simply flattening the frequency response in the frequency domain and looking only at the right and left output channels separately isn't enough. The delay has to be removed, especially if there are different delays for different frequency bands. Those delays look like phase shifts to a matrix processor, and if you have 5.1 or 7.1, some frequencies will be steered to the rear. That's no fun. 

Anyway, here's the procedure I use for manual tuning. MS-8 is designed to provide the same outcome, but the tools are different, so the steps inside the box aren't exactly the same and don't correspond to the order in which information is entered in setup. 

1. Time alignment. This should be done without any low pass filters. Don't try to do this all by ear. If you have a mic and a PC, there are plenty of inexpensive programs that will allow you to make impulse response measurements. If you'll do this by making acoustic measurements, it's important to allow woofers and midbass drivers to output high frequencies because they make it much easier to locate the first peak in the impulse. This is a long and somewhat complicated explanation, so let's just say you're willing to take my word for it. 

If you don't want to make acoustic measurements, then just use a tape measure. that's good enough. Digital processors usually run at 44.1k or 48k, and the minimum amount of delay that's possible is a single sample--if the processor runs at 48k, that means 1 sample is 1/48,000 of a second. If sound travels at 1132 ft per second, then one sample equals about .28". That's plenty of resolution, so don't freak out and go on some tirade about what a piece of **** the processor is. That would only make a difference at high frequencies, and we don't hear phase very well above 1k. Measure a straight line from the center of the speaker to the center of your forehead. Good enough.

2. Using an RTA, look at the useable frequency response and bandwidth of the separate speakers. If you're bianping or tri-amping, this is easy. If you're using passive crossovers, then look at each channel separately. Basically, you want to be sure that you're not asking speakers to do something they won't do because of loaction or installation. Never cross a tweeter lower than 2x its resonance if you'll apply anything close to its rated power. For 1" car tweeters, 3k is a pretty good rule of thumb. Set the crossovers in a region where both speakers to be filtered have good output. For example, if your midbass speaker starts rolling off at 120Hz and is -12dB at 60Hz, setting a crossover at 60Hz won't work, no matter how much you wish it would. High pass filters protect drivers and low pass filters provide the blend between the bands. Use steep filters in cars--24dB/octave is plenty. All of this 48dB/octave or greater BS is just a waste of processing power. I'm sure I'll get flamed for that, but I'm right.

3. Combine the speakers that make up one of the front mains--left or right. Leave the subwoofer off. Tune the frequency response of that according to your target. I've posted my target response on this forum at least a hundred times, so I'm not going to type it again. Once that's done, store the graph in your analyzer in a way that makes it easy to match when you do the other channel. Turn that channel off and turn the opposite channel on. Tune the other channel to match the frequency response precisely. Levels should match too. 

3. If you have a center channel, tune it to match the left and right for the band of frequencies they have in common. I recommend a center channel that plays all the way out to 20k if you have some center steering algorithm. If you have a mono (L+R) center, turn it off and take the speaker out. Sell it to someone who has real center channel processing and put a potted plant in place of the speaker you removed. If you do this, be sure to set up a separate tuning for the passenger's seat so while you drive a passenger around, they can enjoy listening while you suffer.

4. Add the sub. Tune the low pass filter and the EQ for the sub according to your target response. Don't worry about the frequency you choose. Forget about overlap or "underlap" because that doesn't apply unless you're tuning for exactly flat response. Another long explanation that I'm not going to type now. Just make sure the combined target response is right.

5. Listen. If you hear something you don't like, don't tune by ear. Get out the mic and identify the problem. Determine if you have EQ that will fix it. If you don't, save what you've done so far, if you have presets. If you don't have presets write down the settings. Use the EQ to try to fix what you don't like. Once you've matched the channels, adjusting to fit the target curve should be done with the same adjustments on both channels. Don't continue tuning channels separately, because that will screw up the match between the channels. If you have peaks when you combine the channels, tune both channels to remove them. If you have dips, you can add a little energy with the EQ to both channels, but if the improvement doesn't match the amount of boost, don't try to fix it. That's a phase problem and can't be fixed in the frequency domain. You'll have to live with it, wait for a better processor or move the speakers. 

That's the procedure I use. It's essential to have a separate EQ for left and right and helpful to have separate EQs for center and sub too. Rear isn't critical. 

Hope that helps. 

MS-8's process is a litle different. You input the crossover frequencies and then it makes measurements. It slices and dices the measurements according to some rules (the algorithm), makes all of its decisions and implements them with a single set of filters per output channel that do time alignment, crossover fine tuning and frequency response correction all in one. That precisely matches the channels according to the target curve--in about 30 seconds. Then, you can adjust the target with a separate 31-band EQ. It isn't an Auto EQ designed for dummies, it's just designed to do the really hard work and the work that currently requires more processing tools than are currently available in any other single processor for cars, efficiently and with less DSP than is included in another product that's designed to do only frequency response based un-eq. Then, you get a tool that makes the fun part of tuning easy. 

Now to the other post about how MS-8 is designed for the masses and isn't appropriate for real audiophiles--this time because it doesn't have a digital input. Sigh...



Questions I still have for Andy regarding how he tunes:

1) In the above I noticed you didn't talk about level matching by itself. I assume you handle it in step 2 or 3. I am of course referring to level matching a fully active setup.

2) Could you please direct me to where you have posted your target response that you try to achieve in the forums. 

THANKS!!!


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## 14642 (May 19, 2008)

Thanks for reposting that. I was about to type it again, because I have no idea how to use the search...

Yeah, level matching happens during the crossover setting and then again during EQ, depending on where the peaks and dips are and what's required to get rid of them.

For a Target curve, I suggest:

+6 to 9dB from 20-60Hz, a smooth transition from 60-160, flat (0dB) from 160 to about 1kHz or so and a slight downward tilt above that. The tilt is a matter of personal preference and can be adjusted however you like.


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## donkeypunch22 (Nov 5, 2008)

Thanks Andy


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## splicer (Oct 4, 2008)

Megalo said:


> It’s all about superior technology.
> 
> Were all talking about the same things here, resistors, capacitors, and inductors.
> 
> Active crossovers use the same components as their passive counterparts, but they are much smaller, and variable.


No they don't. Analog active crossovers use op-amps in the filter, not inductors. Digital active crossovers don't use any of that, they process the signal while it is still just information, a representation of a signal.


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## MarkZ (Dec 5, 2005)

splicer said:


> No they don't. Analog active crossovers use op-amps in the filter, not inductors. Digital active crossovers don't use any of that, they process the signal while it is still just information, a representation of a signal.


They can use inductors. They just usually don't because op amps serve as buffers, so you can get away with a resistor and capacitors. It's a high impedance circuit, so you'd have to either reduce the impedance somewhere or use a really high xover point to accommodate a reasonably sized inductor.

Thing is, a lot of this discussion really shouldn't be ACTIVE vs. PASSIVE. You can design a passive crossover to go BEFORE the amp that would be just as effective as the active (although you'd need a multigang pot for adjustment). So the discussion is really pre-amplifier vs. post-amplifier filtering. It's just that there aren't a whole lot of passive pre-amp filters, except for those "F-mod" things which are designed like crap.

Anyway, I think Megalo's point was valid, at least when you're comparing analog circuits. The passive and active filters are doing basically the same thing. But yeah, DSP is different.


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## t3sn4f2 (Jan 3, 2007)

Doesn't the very same thing that makes using a driving within it's on/off axis an advantage, make it a problem since the other side of that off axis energy is going to be firing into the pedal area and could then narrow the stage?


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## M-Dub (Nov 29, 2006)

t3sn4f2 said:


> Doesn't the very same thing that makes using a driving within it's on/off axis an advantage, make it a problem since the other side of that off axis energy is going to be firing into the pedal area and could then narrow the stage?


Are we having the same conversation here?


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## t3sn4f2 (Jan 3, 2007)

Megalo said:


> Are we having the same conversation here?


Sorry, you lost me. :blush:


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## M-Dub (Nov 29, 2006)

splicer said:


> No they don't. Analog active crossovers use op-amps in the filter, not inductors. Digital active crossovers don't use any of that, they process the signal while it is still just information, a representation of a signal.


Sorry it's been 13 years since college, and I decided not to make a career out of electronics, but back then I built my own active and passive crossovers, even my own amplifiers, equalizers, and AM/FM radios. 

I guess things got a lot more complex since then.


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## Patrick Bateman (Sep 11, 2006)

t3sn4f2 said:


> Doesn't the very same thing that makes using a driving within it's on/off axis an advantage, make it a problem since the other side of that off axis energy is going to be firing into the pedal area and could then narrow the stage?


Reflections in the car don't narrow the stage, they destroy it. Any reflections with a few milliseconds of the initial signal create phantom images. These phantom images muddy the soundstage on the recording.

To create an excellent soundstage in the car, you need to control directivity.

In a home environment it's not a huge deal, since you can simply move the speakers away from the walls.


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## jsun_g (Jun 12, 2008)

My head is pretty sore after reading thru this thread.

There is one thing I have encountered that I see as a strike against passive xovers that I haven't seen mentioned yet. It is a situation where due to the mounting locations, angles, etc., there is a response peak (or dip) around the crossover frequency. Swapping the phase on one driver (or one pair of drivers) hasn't helped, it just turns out to be for example that due to the standard mounting location of the midrange, its response really dips right around the xover frequency, but at a little higher frequency, the response of the tweeter is dominating and it is just fine (no dip). The response issue is due to only the LF drivers/location. Your passive xover point is probably fixed. You might be at least a little lucky to have bi-ampable crossovers driven by amp channels that are EQ'd and time aligned separately so you have some tools to throw at the problem (this is a pseudo-active setup if you think about it). If not, any EQ you perform will affect both the mid and tweet which is not what is intended. Switching the tweeter attenuation to -3dB also won't solve this problem...you'll essentially have an elevated LF response at frequencies below the dip, with the tweet attenuated to align to the dip.


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## 14642 (May 19, 2008)

jsun_g said:


> My head is pretty sore after reading thru this thread.
> 
> There is one thing I have encountered that I see as a strike against passive xovers that I haven't seen mentioned yet. It is a situation where due to the mounting locations, angles, etc., there is a response peak (or dip) around the crossover frequency. .


 
Some investigation of the frequency response of the speaker both on and off axis (not in the car) may reveal that this is a directivity issue and that although the speaker may have flat response when measured on axis, the off axis response includes a hole at the crossover frequency. Put that in a car and the response you hear (the power response, modified by the shape of the reflective surfaces) includes the hole. That's what I've been explaining all along.


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## 14642 (May 19, 2008)

Patrick Bateman said:


> Reflections in the car don't narrow the stage, they destroy it. Any reflections with a few milliseconds of the initial signal create phantom images. These phantom images muddy the soundstage on the recording.
> 
> To create an excellent soundstage in the car, you need to control directivity.
> 
> In a home environment it's not a huge deal, since you can simply move the speakers away from the walls.


Hmmm...I add a bunch of fake early and late reflections to the signal in my car and it improves the stage dramatically and makes the reproduction sound much more natural.


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## Patrick Bateman (Sep 11, 2006)

Andy Wehmeyer said:


> Hmmm...I add a bunch of fake early and late reflections to the signal in my car and it improves the stage dramatically and makes the reproduction sound much more natural.


But you're adding it to the signal. That creates ambience. But reflections in a room (or in a car) create a phantom image that muddies the soundstage.

My hunch is that the additional ambience added in the signal path masks the _real_ reflections in-car, and contributes to an improved sense of space in the recording. Seems reasonable.


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## 14642 (May 19, 2008)

Patrick Bateman said:


> But you're adding it to the signal. That creates ambience. But reflections in a room (or in a car) create a phantom image that muddies the soundstage.
> 
> My hunch is that the additional ambience added in the signal path masks the _real_ reflections in-car, and contributes to an improved sense of space in the recording. Seems reasonable.


Right. 

I don't find that i hear distinct phantom images even without the super-duper processing. What I do find is that the reflections combine with the initial sound to dramatically alter the frequency response of the system. 

At the end of the day, I'm far less concerned with accuracy than I am believability. I had the serious hots for Jessica Rabbit, even though she was a cartoon. I'll settle for a similar experience with regard to audio systems--especially since the recording is rarely an accurate reproduction of a real event.


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## MarkZ (Dec 5, 2005)

Andy Wehmeyer said:


> Hmmm...I add a bunch of fake early and late reflections to the signal in my car and it improves the stage dramatically and makes the reproduction sound much more natural.


How do you do this, specifically?


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## UncleMeat (Jul 14, 2009)

The quality of speakers isn't there in passives until you start spending stupid money (Focal, etc). In this sense, active is a better bang for buck.

Plus, dicking around with an active setup is another part of the hobby.

Lastly, tuning feedback required goes hand and hand with experience. Those more experienced may be able to tune by instincts and ear, while someone less experience may be ill-equipped without sufficient feedback data. Indeed, the use of laptop/mic feedback setups seems underutilized and under-preached here. Though, even a complete moron can generally make well advised purchased speakers, typically installed, sound better than most oem setups.


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## 14642 (May 19, 2008)

MarkZ said:


> How do you do this, specifically?


It's basically a pair of convolution reverbs with synthesized impulse responses that can be adjusted for length and frequency response. Those impulses and the adjustments are the proprietary secret sauce.


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## chad (Jun 30, 2005)

donkeypunch22 said:


> [Andy]
> 
> 1. Time alignment. This should be done without any low pass filters. Don't try to do this all by ear. If you have a mic and a PC, there are plenty of inexpensive programs that will allow you to make impulse response measurements. If you'll do this by making acoustic measurements, it's important to allow woofers and midbass drivers to output high frequencies because they make it much easier to locate the first peak in the impulse. This is a long and somewhat complicated explanation, so let's just say you're willing to take my word for it.


I could not agree more, this is rather important. 

BUT I woulld like to add, if you are one of those using a really low XO frequency for the sub and using a vented box especially, it would not hurt to look at the group delay of the sub system

If I don't release the LPF and tame down the low end a bit smaart will actually SEE this group delay big time in my car. Even though I do use a higher crossover frequency.


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## 14642 (May 19, 2008)

chad said:


> I could not agree more, this is rather important.
> 
> BUT I woulld like to add, if you are one of those using a really low XO frequency for the sub and using a vented box especially, it would not hurt to look at the group delay of the sub system
> 
> If I don't release the LPF and tame down the low end a bit smaart will actually SEE this group delay big time in my car. Even though I do use a higher crossover frequency.


I find that so long as the phase is close between the mids and the sub in the crossover region, time alignment on the subs isn't necessary if the XO frequency is c. 50 Hz. Wavelengths are too long to be affected much by a few inches in PLD. At much higher frequencies or in a suburban with the subs in the way-back, maybe.


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## chad (Jun 30, 2005)

Andy Wehmeyer said:


> I find that so long as the phase is close between the mids and the sub in the crossover region, time alignment on the subs isn't necessary if the XO frequency is c. 50 Hz. Wavelengths are too long to be affected much by a few inches in PLD. At much higher frequencies or in a suburban with the subs in the way-back, maybe.


I agree about the phase thing, but I have seen issues when crossed in that high group delay region many times, for example at 35 cycles my group delay is 15 milliseconds... that's getting a little too far out there for my tastes.

BUT since I cross higher... where the group delay is 2 milliseconds, phase matching does well. but I know some people that cross that low, "why" is beyond me but I thought I'd throw it out there.


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## Vigarisa (Dec 10, 2007)

Patrick, 

I believe, as you said, that crossovers are critical for the success of a system. I also believe digital active crossovers can kill a response of the speakers and audio as a whole.

There are few exceptions, but the majority of passive crossovers that comes in stock component sets are crap. And they need to be, sometimes, to protect average users, that listen in a high SPL.

Also, what I believe is the "seasoning" for the set, the choice of capacitors is critical. A company cannot use too expensive caps, resistors, inductors. Zobels, L-Pads, notchs are not to use with every setup, each composition has to be studied and tested to get the best crossover out of it. And the art of building a really good and complete crossover is for a few lucky b. or dedicated audio engineers.

Another type of crossover is the non-digital active, such as the old school Nakamichi EC-204 or EC-302. That is a good piece every DIYer should have, IMHO. It's a good sounding active crossover (non-digital), and helps to get things started on development of x-over points, transitions. 

My friend has also developed a linkwitz alike active crossover (although some of the Linkwitz calculations were a bit wrong haha) and we used it at pre-amp level. It was a good solution too.

So digital active x-over is a lot more simple and cheap, it's made for everyone to use it.

Thanks for reading all of it, it was way too long answer 





Patrick Bateman said:


> People on here are frequently recommending that active crossovers should be used in lieu of the passive crossovers which come with their component speakers.
> 
> This is mystifying to me. IMHO the crossover is the most critical component in any loudspeaker. It can take months or even years to perfect a passive crossover.
> 
> ...


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## MarkZ (Dec 5, 2005)

Andy Wehmeyer said:


> It's basically a pair of convolution reverbs with synthesized impulse responses that can be adjusted for length and frequency response. Those impulses and the adjustments are the proprietary secret sauce.


Do you do this with VST plugins?


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## audiodelic (Jul 23, 2017)

Great thread, lot of good information here


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## PPI_GUY (Dec 20, 2007)

audiodelic said:


> Great thread, lot of good information here


Holy necro-thread!
But, you're right. There is some good info here.


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## jackal28 (Sep 23, 2017)

Not sure if this has been mentioned yet, but active crossovers allow for the amplifiers power to only be utilized on the desired frequency instead of the amplification of all frequencies and then attempted removal of certain ones. Also, crossover quality and accuracy does come to mind.


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## drop1 (Jul 26, 2015)

Andy Wehmeyer said:


> MarkZ said:
> 
> 
> > How do you do this, specifically?
> ...


I did something similar a few years ago. I ran my entire system through my music computer and daw. The combination of added reverb on the rear fill and mid/side eq combined with some othet very subtle effects made for quite an experience.

On topic i like passives when i can use them. I spent the money on the frog passives because you went the extra step and gave them 12 db of fully adjustable attenuation. I was a little sad that the crossovers are not bi amp. Im sure there was a reason, may I ask what it is?
Luckily for me the drivers on each side are within 1/2 inch from my ears. The full gb setup combined with the helix dsp is very impresssive.


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## gumbeelee (Jan 3, 2011)

Hell i didnt even know passives were still sold...


Sent from my iPad using Tapatalk


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## thornygravy (May 28, 2016)

It's so worth it.


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