# crossover confusion



## BigRobRN1 (Jul 21, 2010)

I've done a lot of reading and googling and searching, but most what I have read deals with active vs strictly passive crossover setups. 
I've read use only one crossover, I've read use 2 crossovers, I've read use the crossover on the amp, the passive, and the headunit crossover.
So, I am seeking some decent clarification.
My current setup is a front stage 2 way component (CT strato 6.5 mids and the 25mm silk dome tweeter with passive crossover) and a single 12" subwoofer.
I have a Pioneer PRS class FD amp on my front stage. Its a 2 channel amp running stereo, 125 watts x 2. Pioneer GM 9601 on my 12" sub. 

On my subwoofer, I bypass the crossover (set it to full range) and simply let the crossover built into my Pioneer AVH headunit to the rest. No problems. 

On my Pioneer PRS FD amp that feeds my front stage, I bypass the crossover on the amp (set it to full range) and I use the passive crossovers that come with my CT Sounds components. This is where my confusion lies. 
I feel when I turn on and set my HPF on my Pioneer headunit on my front stage, that I'm blocking too much of the sound (mids, guitar, drums) when listening to certain music, aka rock n roll, guns n roses, jazz, etc.
When I bypass the HPF on the headunit when listening to something with heavy bass aka techno, rap, hip hop, I feel the bass may be too strong that is getting thru and the passive crossover isn't doing a good enough job. 

Now, with this being said, I'm not planning on getting a 4 channel amp and going active. I'm not at that point and that requires a new amp, possibly a complicated external crossover or epicenter, and lots of tuning. 
Also, I know this passive crossover that came with the components may well be a piece of junk. 
I'm just trying to find a happy medium. There is no getting around the passive crossover that came with the components. I understand that and I need to be using it, I'm just trying to find the right balance when using both the included passive crossover and the headunit crossover. The amp crossover is not in the equation. 

Any advice is welcome. 
Thank you.


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## Theslaking (Oct 8, 2013)

Use only 1 crossover. HU is likely best. The passive crossover from factory will likely do it's job protecting the speakers from unwanted signal. It won't however correct other things such as poor placement/installation, over powering, EQ adjustment, time alignment, etc. Adding the HU crossover to the passive is not really bad. However that won't likely help with the tweets. It will only make the 6.5 pick up higher, say at 90-100hz or cut off the top end. Both of these things could help.

Sound deadening and speaker placement are things that can make a huge difference, especially when staying passive. Passive systems can sound very good.


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## miniSQ (Aug 4, 2009)

what is the HP crossover on you HU set to when passing signal to the front speakers?


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## Holmz (Jul 12, 2017)

The passive crossover in the speakers limits the frequencies to the tweeters and the midrange/woofers.
And an active crossover does the same thing.

So one generally picks one.

However it sounds like the crossover in the head unit maybe set too high for the 2-way speakers when it is engaged...
If tyne head unit has some cut off frequency then I would try to lower it and get it seeming right (maybe a bit thin on the woofer end) with the sub disconnected.
The adding the sub back in adjust the gain to give it the right level compared to the upper frequencies.

But ^this^ is all mostly an educated/theoretical guess.


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## BigRobRN1 (Jul 21, 2010)

I have my Pioneer headunit HPF filter set at 80hz with a -12db slope
I have the LPF on my sub set at 80hz with a -12 db slope


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## BigRobRN1 (Jul 21, 2010)

Do these settings sound ok?
Should I experiment with some other settings?

Also, I honestly don't see how I can get away with just using 1 crossover unless its just simply using the passive crossover that came with the components. I don't see anyway around it.


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## Theslaking (Oct 8, 2013)

Don't use more than 1 active crossover for the same speakers. Like the amp and HU. The factory crossovers usually are not ideal but that is what you have so don't worry about that much.

What HU is it? What is your HU crossover options? Is it a powered HU?


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## Holmz (Jul 12, 2017)

BigRobRN1 said:


> Do these settings sound ok?
> Should I experiment with some other settings?


Probably...
and taking notes when you do that


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## Theslaking (Oct 8, 2013)

What HU is it? What is your HU crossover options? Is it a powered HU?


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## t3sn4f2 (Jan 3, 2007)

Try using a steeper slope on your xover points (ie 24dB/oct).


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## BigRobRN1 (Jul 21, 2010)

Theslaking said:


> What HU is it? What is your HU crossover options? Is it a powered HU?


My HU is a Pioneer AVH3800. It has front, rear and sub outputs. 13 band parmetric eq. 
High pass filter, low pass filter with selectable frequencies and slopes from -6, to -24. 
I am not using the HU to power and speakers. I have my front signal cables to my Pioneer PRS class FD amp, and the sub output to my Pioneer GM 9601 sub amp.
Crossover points are 50, 63, 80, 100, 125, 160, 200 hz.


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## SPLEclipse (Aug 17, 2012)

The passive crossover only effects the point where the midrange hands off to the tweeters. It doesn't provide any high-pass filter to keep the low frequencies out of the midrange.

You can use any and all combinations of active filters you like. The right one or combination of more than on is whatever sounds good and isn't going to lead to damage.

You can try lowering the HPF on the front stage from 80 to 63 if you'd like. Make sure the mids aren't being driven too hard if you do this. You could also try defeating the HPF on the headunit and using the one on the amp if it has more adjustability. You could also cascade the filters to create higher-order ones. Maybe set the headunit's HPF to 50hz and use the amp's HPF to dial it in?

Another thing to consider is raising the LPF on the sub. It might work it might not. You can also try swapping the polarity on the sub (reverse the - and + speaker wires inbetween the sub and the amp) to see if you get better phase alignment between the sub and the midrange.

Play around with it until it sounds as good as you can make it.


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## Thee Unforgiven (Mar 26, 2017)

SPLEclipse said:


> . You can also try swapping the polarity on the sub (reverse the - and + speaker wires inbetween the sub and the amp) to see if you get better phase alignment between the sub and the midrange.
> 
> .


fyi, the pioneer 3800 has a button to swap them. i did this just yesterday.


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## BigRobRN1 (Jul 21, 2010)

SPLEclipse said:


> The passive crossover only effects the point where the midrange hands off to the tweeters. It doesn't provide any high-pass filter to keep the low frequencies out of the midrange.
> 
> You can use any and all combinations of active filters you like. The right one or combination of more than on is whatever sounds good and isn't going to lead to damage.
> 
> ...


Ok, this is starting to make more sense. 
So if the crossover point is 4.5khz on my passive crossover, that means any frequencies from 0-4500 hz will be seen by the 6.5" midrange, and the frequencies above that will be sent to the tweeter.

Ok, so if going active, how in the world do you keep damaging low frequencies, lets say below 4500hz from getting to the tweeter? Do they have a built in "bass blocker" or capacitor? 
I've never seen a crossover adjustment dealing with frequencies that high and can see how going active could take a lot to time dialing in frequencies that high. Even some of the higher end 4 channel amps that would be directly wired to a tweeter, I can't say I've seen adjustments that high. I will have to do some more research. 

I've always been simple and let a passive crossover handle it. 

But, with that being said, I think I will experiment with defeating the crossover on my HU, turning off my subwoofer, and seeing how powerful the low frequencies will play thru the 6.5 mids. I will take the advice and try dialing in the Pioneer prs amp's crossover to keep the lower frequencies from passing thru. 
I honestly thought that the passive crossover would keep the low lows, like 50 hz or below, from passing thru. 

I can see how this can take some time getting right. But I'm learing. Heck, who knows, maybe one day I'll take a stab at going active. I do have a spare 4 channel amp.......


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## SPLEclipse (Aug 17, 2012)

BigRobRN1 said:


> Ok, this is starting to make more sense.
> So if the crossover point is 4.5khz on my passive crossover, that means any frequencies from 0-4500 hz will be seen by the 6.5" midrange, and the frequencies above that will be sent to the tweeter.
> 
> _Yes. If you want to do more research on this you can research slope orders (1st order -6dB/oct, 2nd order -12dB/oct, etc...). That will be helpful if you go active but isnt' generally something to worry about for now._
> ...


.....


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## BigRobRN1 (Jul 21, 2010)

All Great advice. I appreciate it.

P.S. I just checked my Pioneer PRS-d800 amp. Its a full range class FD amp with no crossover capability. It looks like I'll be experimenting with the HU crossover points and the other options suggested.


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## Alrojoca (Oct 5, 2012)

With that HU, the only reason to use the passives is to have rear speakers.

Pretty much all aftermarket HU have a hpf in standard mode knowing that if either components or coax speakers will be used it will keep low freqs to play to protect the the woofer drivers.

The passive xover has hpf for the tweeters and a lpf for the woofers, by setting the HU hpf you protect the woofer from low freq or excursion with rated or extra power.

If no rear speakers are needed and you want a more clean and better front stage, you will need to bi amp in the network mode those components, 2 channels for the tweeters and 2 channels for the woofers. The woofer channels have a hpf and lpf where you limit the freq range, and the tweeter channels have an hpf targeting higher freq all above an x point.
Active network would mean, remove the component passive xovers. 

Example
Ch 1-2 tweeters, hpf 4000 Hz or doble the FS spec and a bit more to be safe.
Ch 3-4 woofers hpf 80hz lpf 3000 or 4000 Hz 
Sub channnel lpf 80 Hz 
Every car is different, different x points, slopes and EQ will deliver different results in different cars, the trick with active, is to level match the 4 channels before EQ and other settings including time alignment usually having to cut output on the left channels for a more centered stage, and that's another topic. The main thing is to get good tonality after level matching the drivers. The passives make it way simpler since it would be accurate almost a plug and play situation.


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## BigRobRN1 (Jul 21, 2010)

Alrojoca said:


> If no rear speakers are needed and you want a more clean and better front stage, you will need to bi amp in the network mode those components, 2 channels for the tweeters and 2 channels for the woofers. The woofer channels have a hpf and lpf where you limit the freq range, and the tweeter channels have an hpf targeting higher freq all above an x point.
> Active network would mean, remove the component passive xovers.


I am on board with most of what you are saying, and I realize I do have a network mode with my HU. I don't know how it works but I will read up on it. 
What confuses me is the Bi-amp part. Does that mean using another 2 channel amp? 1 two channel amp for tweets, 1 two channel amp for mids?
Would a 4 channel amp work instead? Or is bi-amping strictly designed for network mode?


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## BigRobRN1 (Jul 21, 2010)

Well by gholly, I just watched a 30 minute video on what this network mode is. 
It really should be named ACTIVE mode. 
I did not realize this Pioneer AVH 3800 had the option to run an active setup. 
I think I like the idea of high, mid, low in comparison to front, rear, sub. 
Of course this fits for me because I am not using rear speakers. 
This seems much more logical than having to go to the amplifier to make the adjustments (my amp is in the trunk).

SOOOOO, who knows what I may decide to do.


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## Alrojoca (Oct 5, 2012)

A 4 ch amp is good, almost all 4 ch amps have an all pass or no filter open position and you will have all the tuning control from the head unit 

2 ch for the tweeters 2 ch for the woofers. When separated you have pre amp filtering, cleaner sound, with a passive, you share 4 drivers with 2 channels each channel splits the power to a set of woofers and tweeters, it's a post amplified signal meaning some power is lost in the signal. You will also need a mono amp or a 5 ch single amp can run a 2 way front active system 

As I mentioned before challenge or what takes some time and good hearing is not so much setting the xover points, since based on specs you know the range, it's more the level matching of both tweeters and woofers, and your HU has a powerful processor since you could reduce the levels in pairs to start, tweeters tend to sound strong or harsh in active mode being more sensitive and needing less power to sound good, you can start with minus 3 or 4 db try if the blend with the woofers and go from there.
The importance of active filtering is more control of time alignment levels of individual channels due to biamping for a more centered stage above the dash.
Start with it slow, don't jump into a freaking 8 ch sound processor with 32 bands per channel yet as some will suggest, you will be lost having a laptop to tune it dealing with software glitches and issues, unless you want to deal with that.


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## BigRobRN1 (Jul 21, 2010)

Sounds good. I'm looking forward to it. 
With a HU that can run a dedicated active setup, I'm definitely leaning towards it now.


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## Shane (Oct 8, 2009)

also remember that if you adjust your gains, you are messing with your crossover / crossover points as it adjusts with other drivers. Because where the slope intersects with the other speakers, that intersection point will move with any adjustment in the gain setting.

Just another thing to be aware of, that's all. This is why its absolutely necessary to have a mic and RTA as one of your tools when tuning.


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## BigRobRN1 (Jul 21, 2010)

Ah, yes, another caveat...


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## Alrojoca (Oct 5, 2012)

You can do fine using your ears and some basic guidelines, then fine tune it to your taste, it does not have to be a science project


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## BigRobRN1 (Jul 21, 2010)

Alrojoca said:


> You can do fine using your ears and some basic guidelines, then fine tune it to your taste, it does not have to be a science project


I don't see myself spending $500 - 1500 on an RTA, although for the OCD audiophile it is probably a must. 
I will set it up using some basic parameters and the most common frequencies and slopes as suggested on some tutorials I have read on here and other forums. I will probably set the gain on the amps like I usually do, then make all other adjustments on the HU. 
I usually have my eq set to flat, bass boost 0, all speaker levels set to 0, sub set from 5-10 depending on how I'm feeling, bass boost to 0 and my remote sub knob set to 0. 
On the Pioneer HU I can change each speaker level independently, and there is also an auto Time alignment feature that changes the listening sound according to seated position. I dibble dabbled with it a little this morning and it does make a difference. It changes the decibel levels on the speakers under the speaker level tab, and it changes the "inches" of the speakers on the time alignment tab. That is a bit OVER my head.

I don't have my speaker placement in my Altima I guess what is referred to as ON AXIS. I don't particularly care for speakers pointed directly at my ears. This may be a big factor in time alignment and getting the speakers dialed in when going to an active front stage setup.


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## dcfis (Sep 9, 2016)

A $75 mic and rew is free


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