# is it better to eq before or after the active crossover?



## 60ndown (Feb 8, 2007)

thoughts?


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## Soundsaround (Apr 22, 2006)

Eq post crossover. That way the eq only effects the driver with the issue in question. Also, it's always best to "eq" with the crossover settings if possible. At least for those not so confident with eq.


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## 60ndown (Feb 8, 2007)

Soundsaround said:


> Eq post crossover. That way the eq only effects the driver with the issue in question. Also, it's always best to "eq" with the crossover settings if possible. At least for those not so confident with eq.


great, so now i have to run 3 pairs of rcas from my trunk mounted crossover, back to my indash eq and then back to the amps.


kinda makes all the processing/eq in my 880 obsolete, 

they should have made it 4 way capable. 

ALL my car audio problems would be gone.


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## Soundsaround (Apr 22, 2006)

Nah, it's not an absolute requirement. Just be careful when you eq near the crossover points.


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## candaddy (May 21, 2008)

The only advantage to doing it after is you can tune each driver individually. Personally I do it before because I can't justify the complexity of multiple eq's and cables, etc. and I think you'll find that with most everyone else as well. It's really not practical to do it any other way.

Leave your EQ flat (no adjustments) until you feel you've tuned your system completely as best you can with mechanical (driver placement, aiming, sound deadening, etc.) and electrical (crossover slopes/frequencies) methods. 

I start from the lower frequencies and move up, I'm told that's the fastest way to do it correctly.


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## mvw2 (Oct 2, 2005)

It's easiest to think of both as an EQ. Really, when choosing slopes and proximity, that's all you're doing. You're just EQing the response between the two drivers. The sum of the two drivers can create a dip, be flat, or create a boost around the crossover point. There's more to it of course, but really in a large part, that's all you're doing. You generally shoot for flat, but at the same time, you can address frequency response issues of the drivers around the crossover point. You can also run over it with a normal EQ to balance everything out. The end result will be the sum of each driver plus the sum of the EQ added or cut.

Just make sure you keep the x-over points within a useful range for the drivers. As well, make sure you're well aware of the time domain and any relative delay between the drivers. If one is reaching your ear first, it will be dominant and will sound overly loud even though it's not really any louder than the other. This is always something to keep in the back of your head when attenuating speakers, setting x-over points, and such. Generally there is more than one thing going on that you have to keep a mental note for.


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## Tommythecat (Apr 6, 2006)

I'll just say that with the processing available in car audio - you're screwed. It would be much better to have seperate channels of EQ, XO, time delay, and gain. To tune you would: set gain, eq drivers to "flat" through passband and crossover region, check gains, apply crossovers, check gains, flip phase and delay until you achieve the largest null at the crossover, and then repeat for the other door. Then you want to try and match both sides.


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## GlasSman (Nov 14, 2006)

Which is why the PXA-H700/701 is so popular.

Seperate EQ, XO, level setting, phase and time alignment for each speaker.


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## BMWturbo (Apr 11, 2008)

I say before...

If you have 1/3rd band EQ, you are not using all it's functionality limiting it to a specific drivers bandwidth.

Why waste all those bands that you coudl potentially use to adjsut all drivers, by limiting it to one pair?


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## michaelsil1 (May 24, 2007)

60ndown said:


> they should have made it 4 way capable.
> 
> ALL my car audio problems would be gone.


Nah you would have found something else.


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## chad (Jun 30, 2005)

When using DSP in my pro rigs I EQ after the crossover to correct for driver/box irregularities, this is normally done as anechoicly as possible (in the pasture for tuning day) But for "voicing" and room correction, before the crossover, on a permanently installed rig only for voicing for the EQ before the XO, It's nice to have something to grab and go instead of jacking with the parametric per passband.

If I didn't have DSP, screw it, before the crossover, I ain't going thru the trouble.

Chad


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## 60ndown (Feb 8, 2007)

michaelsil1 said:


> Nah you would have found something else.


you should know.

you gotta move your tweets and new pods for the midbass


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## michaelsil1 (May 24, 2007)

60ndown said:


> you should know.
> 
> you gotta move your tweets and new pods for the midbass


Maybe I should take your advice and stay out of better sounding cars.


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## 60ndown (Feb 8, 2007)

michaelsil1 said:


> Maybe I should take your advice and stay out of better sounding cars.


better/different.


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## michaelsil1 (May 24, 2007)

60ndown said:


> better/different.


Since this post is about is it better to EQ before or after the crossover. I believe going back to the install can eliminate some of the need to EQ.


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## 60ndown (Feb 8, 2007)

michaelsil1 said:


> Since this post is about is it better to EQ before or after the crossover. I believe going back to the install can eliminate some of the need to EQ.


ok, but when your done tweakng things, eq b4 or after x over?
in yure opinion.


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## michaelsil1 (May 24, 2007)

60ndown said:


> ok, but when your done tweakng things, eq b4 or after x over?
> in yure opinion.



Well you definitely got me thinking.

There's advanced compression techniques (Hardware) used to fine tune before the crossover it seems very difficult to use, but would probably yield the best results; I don't think it's practical to use in a car.

Overprocessing is almost always more damaging to a piece of audio than underprocessing. 

I would have to say for a car and ease of use, after the crossover unless you have the expertise of someone like Chad.


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## Nitin (May 28, 2008)

so the guys who say to eq after the crossover ...... how many EQ's do you guys want to use - now you need an EQ for the sub channels - then you need an EQ for the midbass/mid channels (could be up to 4 channels in a three way setup) then you would need an EQ for the tweeter channels 

so do you want to use 4 EQ's - considering you dont really know where the problematic frequencies are - or most likely that you have more than one problematic area 

you can get the same EQ functionality out of 1 EQ before the crossover but with adjustability over the entire audio spectrum - if your problem cannot be resolved in that manner in my humble opinion you have a problem that needs more than EQ to resolve - pro audio is another kettle of fish 

but IMHO you really need to keep things as simple as possible - cos having multiple EQ's is just giving you more things that can potentially go wrong and also allowing the danger of increasing your noise floor and really can your cars electrical system do with having more equipment to power up (how would you really apply EQ to the full audio spectrum without multiple EQ ....... i have dips at 250hz and 2500hz and then peaks at 6khz and 10khz up to around 16khz)


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## michaelsil1 (May 24, 2007)

When using the HU Active is the built in EQ before or after the Crossovers?


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## 60ndown (Feb 8, 2007)

Nitin said:


> so the guys who say to eq after the crossover ...... how many EQ's do you guys want to use - now you need an EQ for the sub channels - then you need an EQ for the midbass/mid channels (could be up to 4 channels in a three way setup) then you would need an EQ for the tweeter channels
> 
> so do you want to use 4 EQ's - considering you dont really know where the problematic frequencies are - or most likely that you have more than one problematic area
> 
> ...


great thinking. i was unsure but now im with you on this.



michaelsil1 said:


> When using the HU Active is the built in EQ before or after the Crossovers?



no idea?:blush:


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## Soundsaround (Apr 22, 2006)

Nitin said:


> so the guys who say to eq after the crossover ...... how many EQ's do you guys want to use - now you need an EQ for the sub channels - then you need an EQ for the midbass/mid channels (could be up to 4 channels in a three way setup) then you would need an EQ for the tweeter channels
> 
> so do you want to use 4 EQ's - considering you dont really know where the problematic frequencies are - or most likely that you have more than one problematic area
> 
> ...


No argument at all on any of the practicality points, and for most folks installing in a car, it does all come down to practicality. But the "technically correct in a vacuum without weighing other concerns" answer is crossover before eq.

Imagine you have big boomin' door mounted midbasses crossing over to a pair of 3" midranges, dash mounted in undersized enclosures. If your car is anything like mine, those door mounted midbasses are going to need some serious eq cuts in the 150-300 range to reduce muddiness. At the same time your mids are struggling to get down to the desired, say 250hz crossover point. Although this situation should be remedied by better installation or crossover tweeks, practicality doesn't always allow that and many people will turn to eq.
Now your in a dilemma because your eq cuts intended for the midbass are adversely effecting your mids and vice versa. 2 eq's post crossover and no more worries, or rather, less worries  

I personally, have the dual 16 band graphic in the h/u, plus 2 analog, 4 band fully parametrics with overlapping ranges covering 20hz-20k. I use most of the graphic bands and at this point in the install I've got it down to only 2 bands of parametric. The second parametric is now in a closet.



michaelsil1 said:


> When using the HU Active is the built in EQ before or after the Crossovers?


I have no insight into the internal designs of headunits, but I'd be really, really surprised if it wasn't crossover first, then eq.


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