# 3 way front + Sub w/ DEH-80PRS



## joshchrans (Mar 11, 2012)

I would like to run 3 way active up front + sub with a Pioneer DEH-80PRS. Forgive the noobiness of this, but if I run the Pioneer outs HP to the tweets, BP to the widebands, LP to the midbasses (with a HP from the amp's internal xover), can I also use the line out from the midbass amp to run into my sub amp, and use the internal xover for the sub.

So, I guess Im asking if I can send a signal that is already LP @ about 500hz to my sub amp to be LP @ 63hz? I guess simple logic says yes, but Id better check before pressing order.


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## JohnnyTwoTone (Sep 7, 2008)

You CAN do that if the line-outs are pass-through (which they should be, of course). If they are pass-through than that is precisely why they are there. Well, sort of. The top intended priority may not be to act as a splitter but the signal is supposed to come out of the line-outs unaltered from the signal that went into the amp. It's top intended priority is to allow you to add another amp to power even more subs without having to add an RCA splitter before either amp. So whether you then chose to fool around with that second amp's settings or not is up to you. I'd also check to see what the voltage is supposed to be coming out of the line-outs, as that may alter how you need to set the gain on the second amp.


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## ZAKOH (Nov 26, 2010)

joshchrans said:


> I would like to run 3 way active up front + sub with a Pioneer DEH-80PRS. Forgive the noobiness of this, but if I run the Pioneer outs HP to the tweets, BP to the widebands, LP to the midbasses (with a HP from the amp's internal xover), can I also use the line out from the midbass amp to run into my sub amp, and use the internal xover for the sub.
> 
> So, I guess Im asking if I can send a signal that is already LP @ about 500hz to my sub amp to be LP @ 63hz? I guess simple logic says yes, but Id better check before pressing order.


You can do this, but you will not be able to enjoy all benefits of the active front stage without messing out sub output.

For example, if time alignment is used, the signal to the midbass driver that's closest to you will be delayed (say left signal) compared to the right channel. So far so good, but then.. this, already altered by DEH-80PRS, signal will exit the first amplifier and enter the second. The second amplifier will combine left and right into a mono signal. At this point this may add mud to your subwoofer output. One way to avoid this mud is to throw away one of the channels (say left) at the first amps rca out. Just use the left rca out, split it with a Y-splitter, and plug that into the subwoofer amplifier. Unfortunately, this can't be optimal for SQ again. There are recordings (live music, SQ stuff, etc) where the left channel bass may be different from right channel bass. If you throw either channel away, then that will result in changes in the subwoofer frequency response compared to the original recording. This is why I don't like amplifiers that can't sum stereo signal for subwoofer duty (e.g. all of currently made MB Quart mono block amplifiers) when the head unit sends stereo signal on its subwoofer outputs.

Next, you can try NOT using time alignment on the midbass channels. In this case, the signal is not time delayed on either channel, and so your subwoofer output will not be mudded up. However, the issue now is that you can't use time alignment on midbass drivers. I honestly don't know how important is this limitation. I assume TA for midbass drivers could help to get them in phase, so you won't be able to get this benefit of the active front if you don't want to add distortion to subwoofer output.

One thing I might have suggested is to use a good coaxial speaker with a passive crossover for the mid and high frequencies or a wide band woofer, combined with a dedicated midbass. However, I believe DEH-80PRS crossovers are not flexible enough for this setup. This is because the tweeter out can not be high passed below 1KHz, while the mid out has to have some kind of low pass on the high end with highest setting being about 12KHz. So there is no good way to run a wideband driver that could say cover the whole spectrum from 250Hz and up. So it seems that with this HU you can have 2-way active front + subwoofer, or 3-way active without subwoofer. Choose one.


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## justinshorb (Mar 31, 2013)

I know this is an old thread, but it's exactly what I'm trying to do right now. it was suggested that I run a crossover (audio control 2sx) to split the mid and mid bass. but wouldn't I get better crossover point control if I split the low pass signal into the mid bass and sub output? how high does the lp on the 80prs go?


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## justinshorb (Mar 31, 2013)

for example:

hp 3500hz to the tweets 
BP 500hz 3500hz to the mids 
lp 500hz to the 2sx
and then run the hp from the 2sx to the mid bass and the lp to the sub.

that way if I wanted to separate the mids and tweets I could do that, instead of being stuck with the same crossover point.


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## KrossoverPT (Nov 7, 2011)

Where are you going to install the midrange and the tweeter? one next to each other whith a costum crossover, you could do it.


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## justinshorb (Mar 31, 2013)

the midrange and tweeter are going to be next to each other on the dash.


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## Bayboy (Dec 29, 2010)

Use standard mode.... the only difference are the lack of 3-way xover points, but you can make up for it using your separate xover in conjunction with the available hi pass points on the midbass channel. Put the midrange and tweet on the same channel and keep them next to each other then all channels can still use t/a.


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## justinshorb (Mar 31, 2013)

wouldn't that defeat the point of a 3 way setup? unless I'm not understanding something.


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## Bayboy (Dec 29, 2010)

Still 3-way, you're just not using the headunit solely to obtain it. 

Put it like this... unless you want to live with the limited low pass on the midbass at over 1khz you need to run standard mode which still has a high pass on the midbass.

Use the outboard xover on the amp or whatever you have available on that channel besides the headunit to choose your new low pass frequency for it which will complete the mibass bandpass filter. That's if you want to be able to time align them separately from the midrange and tweets. 

Use an outboard xover to split the midrange and tweet although they will share the same channels from the headunit. Of course you will have to use separate amps for them (4 channel) or use passive if you only have a two channel.

Pretty simple although explaining it through my phone on tapatalk may complicate my conveyance.


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## Bayboy (Dec 29, 2010)

It would help to know what amps are you using. I have 50-500hz hi/lo xovers on my amps so you can see how I will be able to split the frequencies. I will have to use an external xover that goes high enough to split the midrange & tweet. The 80prs will still control the sub low pass and the midbass high pass. All else is external.


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## justinshorb (Mar 31, 2013)

so I would need another crossover?


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## justinshorb (Mar 31, 2013)

I have an mb quart onx2.1 and onx4.8


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## Bayboy (Dec 29, 2010)

List what you plan to use. If your amps have a sufficient xover then no.


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## Bayboy (Dec 29, 2010)

First let's put things in order... you're doing a 4-way correct? If so you're going to need a total of at least 7 channels unless the midrange and tweets are going passive.


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## justinshorb (Mar 31, 2013)

*facepalm*

I think I got it. the onx4.8 has a hp between 60hz and 13khz and a lp between 30hz and 250hz. the onx2.1 had the same filters.


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## Bayboy (Dec 29, 2010)

250hz low pass on the midbass isn't bad, but isn't as flexible in case you need to shift the points upwards. That's what deterred me from the Onyx line.

Anyways, do you understand the scope of what I was getting at? You will still have t/a, eq, but just limited xover adjustment from the 80prs. The front will run fullrange allowing the Onx4.80 (in 2 channel input mode) xover to split the signal for the midrange & tweet. The 4.80 rear will high pass the midrange close to 250hz or so and you can use a simple passive to filter the midrange lowpass. The tweeter will be where you need it say 3500hz on the 4.80 xover fronts.

The midbass will be highpassed on the 80prs say at 80hz and low passed on the 2.100 (limited to 250hz at it's highest). Sub will be from amp or 80prs. 


Not the absolute best like most would like, but it's doable on a tight budget with some fair amount of adjustment. The question is can the midrange you are wanting to use take a low xover point since the midbass will be limited to 250hz up top?


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## justinshorb (Mar 31, 2013)

the mid range can go down that low, but what affect is that going to have on sound quality? that's a really small range for the mid bass.


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## Bayboy (Dec 29, 2010)

You'd be surprised how it sounds when you have midrange that can go down to around 300-500hz. The sacrifice is output though. If you're fine with that then no worries.

The main focus is to have as much bandwidth coming from a single set with the rest filling in. Lots of threads on here that cover this sort of info.


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## ZAKOH (Nov 26, 2010)

The more I think about this, I think you will be better off using a passive crossover or amplifier's built in crossover between the mid-range and tweeters. Why? Tweeters are the speakers that benefit the least from time alignment. On the other hand, applying time alignment to midbass drivers to get them in phase with each other could be handy. You don't want the sub to hang out on the same channel with them, because once you apply the TA, the left and right signal (at least one of witch is time corrected) will be summed at the sub stage, obviously resulting in distorted signal. TA between the mid-range speakers is also important for imaging. That's why I suggest that the stock passive crossover (or amplifier's crossover) is used to run tweeters from the same channel with mid-range speakers. 

Alternatively, if the midrange are midbass speakers are very close to each other, perhaps this set of speakers is the one that should use the "passive" or amplifier's crossover, as long as path length differences are small.


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## Bayboy (Dec 29, 2010)

That's why I don't get how some say you can't do 4-way with the 80prs. I don't see a problem especially if the midrange & tweet are adjacent. The sacrifice is you can't have all 3 parts of the front stage in different areas like tweet pillars, mid kicks, midbass doors... other than that is just a matter of how you plan to obtain your xover points which is fairly easy with the right amp and/or outboard xover. It's also inexpensive compared to running a 80prs coupled to an outboard DSP. Figure up & compare the cost. I know I have and that's what lead me down this path. With the savings I was able to upgrade the amps.


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## jimmybee1108 (Apr 26, 2011)

Resurrecting dying thread. 
But read on another, someone is trying to run a quasi 3-way with the 80prs, using a passive xover on the highs from the 80prs. The thing is the midrange and tweet would be going from 1.2khz and up. Most likely crossing the tweeter at ~5khz. 
I just think that's a narrow frequency range for the midrange, don't you think? I might be totally down if that method proves to be beneficial. 

As for the TA issue, the midrange and tweet would be right next to each other. So TA wouldn't be that bad. And EQ and leveling would be semi auto and manual.


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## GlassWolf (May 8, 2010)

actually sounds a lot like my own car's system. Pioneer P99RS, DynAudio System 360 3-way front stage, and an Fi Q15 sub, all active. I'm just not getting funky with the wiring. It's a straight 7 channel setup.


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## Bayboy (Dec 29, 2010)

Much cheaper to run it in standard mode and couple it with amps that have flexible xover capabilities like PPI & Soundstream. Still, two of the drivers will have to be in very close proximity whether it's tweet & mid or midbass & mid.


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## jimmybee1108 (Apr 26, 2011)

What about cutting some losses and just running te TB w3s or Fountek fr89s, tweeterless, from 1250 hz and up?


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## Bayboy (Dec 29, 2010)

Really not many losses to cut when you think about it. The top's high-pass may be trapped at 1.25khz, but it also can reduced to a slope of -6db which allows it to bleed down to 600hz. Not perfect, but good enough to keep some midrange lower cues. Now if you have a amp with a high-pass xover that can extend up to 500hz, then you're pretty much golden.


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## jimmybee1108 (Apr 26, 2011)

Lol. Feel like I'm thread jacking, but would that mean you could still run a fullranger (maybe even a tweeter too with separate xover, passive or active) and an 8" midbass like the silver flute or dayton rs225?


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## ZAKOH (Nov 26, 2010)

jimmybee1108 said:


> What about cutting some losses and just running te TB w3s or Fountek fr89s, tweeterless, from 1250 hz and up?



DEH-80PRS does allow you to high pass the "tweeter" channel from 1250Hz in network mode, but not lower than that. This is another limitation of this head unit since there are some popular wide-band speakers that could be high passed much lower than 1250Hz. If you want your high pass to be at 1250Hz, then I guess the DEH-80PRS could work this way. However, this is not a desirable frequency to set your crossovers at. It's right within the mid range, and this will split the vocal range between two speakers on each side. If the speakers are far from each other this could cause poor imaging and phase interference. Even when next to each other, matching timbre could be an issue.

The head unit does allow using a 2-way active front with a wide band speaker, but you need to switch into the standard mode. In the standard mode, treat the front channels as your wide band channel and high pass it at any frequency within the 30 and 300-ish Hz range. Treat the rear channels as your midbass channel and low pass within the 30-300-ish Hz range. One problem with this approach is that your midrange speaker probably still needs a bandpass filter, not just low pass. The high pass component of the band pass could be provided by amplifier's high pass setting. Then you could use the fade function to match the level of the speakers and time alignment should also be usable. However, you will probably lose the AutoEQ functionality. It seems like this will work, but I kind of wonder.. if you don't use AutoEQ and you have to use this kludge to get 2-way active with widebander to work, why not just buy a much cheaper Clarion CZ702?


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## jimmybee1108 (Apr 26, 2011)

Lol. Didn't like the look of the clarion. 
Ill probably just say screw it and get silver flute 6.5s and vifa xt25s and call it a day. 
Still a noob anyway :/


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## ZAKOH (Nov 26, 2010)

This sounds like a good plan.


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## 07azhhr (Dec 28, 2011)

ZAKOH said:


> D
> The head unit does allow using a 2-way active front with a wide band speaker, but you need to switch into the standard mode. In the standard mode, treat the front channels as your wide band channel and high pass it at any frequency within the 30 and 300-ish Hz range. Treat the rear channels as your midbass channel and low pass within the 30-300-ish Hz range. One problem with this approach is that your midrange speaker probably still needs a bandpass filter, not just low pass. The high pass component of the band pass could be provided by amplifier's high pass setting. Then you could use the fade function to match the level of the speakers and time alignment should also be usable. However, you will probably lose the AutoEQ functionality. It seems like this will work, but I kind of wonder.. if you don't use AutoEQ and you have to use this kludge to get 2-way active with widebander to work, why not just buy a much cheaper Clarion CZ702?


The only thing you lose with standard mode is the bandpass XO options. The auto EQ/TA feature still functions normally and so does the driver specific level options. The 16 bands per side eq are still there too.


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