# Db/octave setting question pioneer hu



## poppinjay (Oct 15, 2011)

Hi,

I have just bought a pioneer hu and it has settings for db/ octave slope. Please can someone tell me the best setting to use on front speakers (hertz hi energy 165) it's set on -12db crossed at 100hz but they don't sound as good or get as loud as when I had them on my old alpine ( mainly distortion) . The gains have been set using a scope, but I just can't get them to sound right.... The speakers are not wired active and to be honest I don't quite understand all the octave stuff..


Any help will be appreciated, will I need to use a different slope, do I need to use it if I'm not running active etc?.


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## Jepalan (Jun 27, 2013)

Two main goals when setting crossover slopes:

1) To achieve the best possible blend between drivers (i.e. sub to midbass, midbass to tweets...)

2) Protect drivers from too much low frequency energy to avoid distortion at high SPLs and to avoid damaging the drivers.

Here is a good discussion on the topic:
http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/146761-observation-crossover-slopes.html

For better advice specific to your install, please provide more details on HU model number and the rest of your system (sub, amps, rear speakers, car type...)


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## poppinjay (Oct 15, 2011)

Hi, sorry for the delay...

Car: Toyota corolla hatchback
Sub's: dual 12w0v3 bass wedge ported.
Fronts: hertz hi energy 165
Amp for fronts: rainbow ipaul 4.300 bridged
Amp for sub:jx1000/1d
Hu: pioneer avh-x5700dab

Regards


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## Alrojoca (Oct 5, 2012)

Sounds like a whole process of getting a good front stage midbass and have more sub bass at front.

I suggest, matching the slopes from the mid bass and the sub, try 12 and 18db, and I would cross those hertz at 75-80 Hz HP, and maybe 2500-2700 Hz Lp, slopes matched on all HP and LP, for the sub, same 75-80Hz LP and maybe 30 Hz HP assuming it is tuned around that area or match the port tuning for the box, usually 30-27Hz works well, same match the slopes for HP and LP.

YMMV, you may have to try different slopes, but none lower than 12 db, but those crossing points would be a good start.


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## poppinjay (Oct 15, 2011)

Hi, I understand some of this but the comments from 2500-2700 hz LP onwards confuses me a bit. Can u break it down a bit simpler for me


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## Jepalan (Jun 27, 2013)

poppinjay said:


> Hi, I understand some of this but the comments from 2500-2700 hz LP onwards confuses me a bit. Can u break it down a bit simpler for me


This would be the cross point between midbass & tweeters if you are running active. If you are using the passive crossovers for your hertz front set then you don't need to worry about it.


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## sqnut (Dec 24, 2009)

poppinjay said:


> Hi, I understand some of this but the comments from 2500-2700 hz LP onwards confuses me a bit. Can u break it down a bit simpler for me


Ignore the LP bit. He didn't read your first post slow enough to know that you're running passive and the cross over and slope you're setting is between the sub and mid. A 12 db slope at 100hz hertz means there will be a 12 db attenuation for every octave below 100hz. So 12 db down at 50 and 24db down at 50 hz. 

Cross the mid and sub around 60 and put them on the highest slope that your hu gives you. Do you have an eq? Is anything boosted there? I'm looking at different issues that could be causing distortion. Do you have the sub level boosted? BBE/Loudness etc?


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## Alrojoca (Oct 5, 2012)

If using the hertz passives , then turn the active network mode off, that is why it sounds bad cause the pioneer in network mode will only allow crossing the front channels from 1000 or 1200 HZ and up, that is why you got no bass.

Set it to standard mode, then set the HP around 70-80hz maybe the standard mode slope setting on the pioneer is fixed at at 12 db, if not you can try it at 18 db


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## sqnut (Dec 24, 2009)

Alrojoca said:


> If using the hertz passives , then turn the active network mode off, that is why it sounds bad cause the pioneer in network mode will only allow crossing the front channels from 1000 or 1200 HZ and up, that is why you got no bass.
> 
> Set it to standard mode, then set the HP around 70-80hz maybe the standard mode slope setting on the pioneer is fixed at at 12 db, if not you can try it at 18 db


His HU is a Pio but it doesn't have NTW and STD mode.


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## Alrojoca (Oct 5, 2012)

sqnut said:


> His HU is a Pio but it doesn't have NTW and STD mode.



Mmm from the crutchfield site

4V/6CH Preamp Outputs + Sub Control: The Pioneer AVH-X5700BHS features three pair of 4.0-volt preamp outputs (Front/Rear/Subwoofer). The unit's front and rear preamp output can be faded (front/rear), while the subwoofer preamp output is non-fading. The Pioneer AVH-X5700BHS lets you adjust the subwoofer preamp output's phase (normal/reverse) and volume (+10 to -24).

Crossovers: The AVH-X5700BHS employs high-pass and low-pass crossovers to tailor the head unit to your connected speaker setup.

Standard: Allows you to set the high-pass and low-pass crossover network for a standard Front, Rear, and Subwoofer speaker setup using either speaker-level or low-level outputs.
HPF: The head unit's -6 to -24dB/octave high pass filter only allows frequencies higher than those in the selected range (50, 63, 80, 100, 125, 160, 200Hz) to your front and rear speakers through the unit's speaker-level or line-level outputs.
LPF: The subwoofer preamp output features an -6 to -24dB/octave low pass filter so only frequencies lower than those in the selected range (50, 63, 80, 100, 125, 160, 200Hz) are output to your connected subwoofer.
Network: Allows you to set the high-pass and low-pass crossover network for a complex 3-way speaker system with Highs, Mids, and Sub using low-level outputs only.
Highs: The high-pass crossover for your tweeters can be set to 1.25, 1.6, 2, 2.5, 3.15, 4, 5, 6.3, 8, 10, or 12.5 kHz with a -6 to -36dB/octave roll-off.
Mids: You can set a high-pass and low-pass crossover from your midrange/midbass drivers. The high-pass crossover can be set to 1.25, 1.6, 2, 2.5, 3.15, 4, 5, 6.3, 8, 10, or 12.5 kHz with a -6 to -36dB/octave roll-off. The low-pass crossover can be set to 26, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, or 250 Hz with a -6 to -36dB/octave roll-off.
Lows: The low-pass crossover for your subwoofers can be set to 26, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, or 250 Hz with a -6 to -36dB/octave roll-off.


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## Alrojoca (Oct 5, 2012)

Good luck with that one here in the US, 5700 dab? Not enough info from pioneer, it's silly to create a version with the same model number and lacking the same features as the BHS.



AVH-X5700DAB Pioneer - DVD Player, Screens - Car*Entertainment


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## sqnut (Dec 24, 2009)

poppinjay said:


> Hi, sorry for the delay...
> 
> Car: Toyota corolla hatchback
> Sub's: dual 12w0v3 bass wedge ported.
> ...





Alrojoca said:


> Mmm from the crutchfield site
> 
> 4V/6CH Preamp Outputs + Sub Control: The Pioneer AVH-X5700*BHS* features.........


I hope you copied and pasted from the Crutchfield site and didn't have to type all that.

The AVH X5700DAB from the pio web site AVH-X5700DAB Pioneer - DVD Player, Screens - Car Entertainment


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## Jepalan (Jun 27, 2013)

poppinjay - 

You only need to worry about setting the high-pass filter for your speakers and the low-pass filter for your subs. As already stated, somewhere between 60 and 80 Hz is a good place to start.

If you are using the HPF & LPF setting on your Pioneer HU, then disable the filter settings on your amps. OR use the filter settings on the amps and disable them on the HU. 

Hope that makes sense - Let us know if you have any more questions.


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## poppinjay (Oct 15, 2011)

Cheers for all the responses. The hu does have a network/standard mode and this is on standard 

The eq is flat. I have not activated and loudness etc.

I will give these setting a go and see. Its just as before if I run the fronts on -12db it happens (more distortion high volume) but its alot better on -6db... Just wasn't sure if I could leave them on -6db?? I will try adjusting the hpf/lpf to your recommendations 

Cheers..


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## Jepalan (Jun 27, 2013)

poppinjay said:


> Cheers for all the responses. The hu does have a network/standard mode and this is on standard
> 
> The eq is flat. I have not activated and loudness etc.
> 
> ...


Don't forget to check the HPF/LPF settings on your amps too. You only want to use the filters on the HU OR the amp, not both. Otherwise the settings will interact and results will not be what you think. Either disable the HU HPF & LPF and set at the amps, or disable the amp LPF & HPFs and set only at the HU.


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## Alrojoca (Oct 5, 2012)

Also
The 6 db slope may sound better at lower volumes, at higher volumes it may not work so well, if used, cross at or above 80hz not lower. It's better to EQ increasing the levels for the 60, 100, 120hz bands to get extra bass with a 12 db or higher slope.


Maybe it would be better to match level and TA the subs being the furthest, then set the slopes. 
What Jepalan said is important, defeat the amplifier xovers, set to off or flat, and use the HU xovers for the front channels.


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## poppinjay (Oct 15, 2011)

Hi,

My amp for the fronts is on full pass so I am using the hu to set hpf but the monoblock is set to 100 lpf. So I need to disable the lpf on the sub and just use the hu or turn off on hu and use the mono amp setting??

Cheers.


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## Jepalan (Jun 27, 2013)

poppinjay said:


> So I need to disable the lpf on the sub and just use the hu or turn off on hu and use the mono amp setting??


Yes. Use the LPF from the headunit or from the mono amp, but not both. Personally I prefer to disable the mono amp LPF and use the one on my headunit for convenience.


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## poppinjay (Oct 15, 2011)

Jepalan said:


> Yes. Use the LPF from the headunit or from the mono amp, but not both. Personally I prefer to disable the mono amp LPF and use the one on my headunit for convenience.


OK, I will disable the mono lpf..

Cheers


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## Alrojoca (Oct 5, 2012)

When it comes to Sub's amplifiers, most mono sub amps, do not allow their crossover to be defeated, I checked this JX amp, and I can't tell, or find info, pics show a line before the lowest point, it is hard to tell.


If it can't be defeated, maybe set at 200 and set the HU's at 80 hz. Or HU to off/flat/full and the amp at 80 or same point for the fronts High Pass.


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## nanohead (Oct 21, 2013)

Not so sure if I understand the issue. If there's distortion, then the slope of the crossover should have minimal or zero effect if there's distortion, unless your'e sending a portion of the frequency range that the speakers cannot reproduce. Changing slope won't change anything as far as distortion goes if the crossover points are set appropriate to the drivers themselves.


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