# head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head unit)



## 96jimmyslt (Jan 31, 2011)

*head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head unit)*

I never new this wasn't a typical issue until I went to meet a guy that said he can help me ground the RCA's.

He had a single din pioneer premier and he said he didn't know how to adjust the EQ at all.

I messed with it a little bit, and turned the low's all the way down and the highs all the way up on the EQ, and the clarity was a LOT better.

The main thing I am worried about, is that it did not effect the bass at ALL.

It's as if there was a separate setting for the bass or something.

But in my head unit, the EQ seems to effect EVERYTHING: head unit speaker outs, sub and front RCA outs, you name it.

My deck is an avic f700BT.

I was just curious about this issue if anyone can shed some light on it.

This is exactly how I have the EQ on the head unit set right now.

I have the high pass filter on the head unit at 125.

With the CD playing, I can actually put the sub on 0 (neutral/flat)and it's pretty even. I have yet to test this at max volume though, since I just set it right now.


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## Bayboy (Dec 29, 2010)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*

Simply put...... bleed-thru, harmonics, etc, and the fact that from a profit standpoint it would be unwise for them to give you all the solutions in one box for less. Best solution...... DSP with separate EQ's (front, rear, sub), but you knew this already though, right?!


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## nick650 (Feb 7, 2011)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*

HPF 125 is WAY TO HIGH. What is the frequency range of your speakers? I have mien set at 60 

Tuning of your EQ is off. Bring 50-100 to all flat. Less on the EQ is best, it only adds distortion. Adding that much for your highs seems unneeded and seems your staging needs to be improved. You want to try to use less of the EQ and settings as possible to bring the best out of your audio.


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## Bayboy (Dec 29, 2010)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*



nick650 said:


> HPF 125 is WAY TO HIGH. What is the frequency range of your speakers? I have mien set at 60
> 
> Tuning of your EQ is off. Bring 50-100 to all flat. Less on the EQ is best, it only adds distortion. Adding that much for your highs seems unneeded and seems your staging needs to be improved. You want to try to use less of the EQ and settings as possible to bring the best out of your audio.




No such thing as way too high! He didn't state in this thread what drivers he was running, but if they are limited to that then the rest is in blending and lack of proper eq adjustment. A 80hz-120hz xover point is actually quite normal. The eq is quite overly boosted in the high range, true, but that can pertain to deficiencies in the driver's response and/or location. There isn't much cut in low frequency from the way the eq is set so that could explain why low bass is not affected. What I would expect again is a lack of mid bass output unless there is a horrendous peak around 120hz-200hz (sub box too small or tuned too high?). A xover point and deep eq cuts within the same range would cause a severe dip if that is not the case.

Perhaps the OP should state exactly what gear he is running and how is it powered and configured. You can guess all day long as to what the culprit is if it is actually a problem. I would start from a flat eq, dial in xover the best as possible for low distortion, blend sub with fronts, then make slight eq adjustments (cuts are better). Be watchful of eq adjustments that coincide with any xover points active and passive. Too much can be a bad thing.


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## 96jimmyslt (Jan 31, 2011)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*

Sorry I should have added this before.

polk audio marine rated 2 ways (DB561 and DB461)

The amp I use is a sony xm-4045 and does not have a variable crossover (That's what the RF p500-2 has, right? Where you can adjust the frequencies a lot?) It only has 80Hz and flat for both the low and high sides

Sub amp is RF p500-2 tuned to about 100Hz or something (I made sure to dual it in to get the voices out)

Subs are old school audiobahn 12"s in audiobahn sealed box (before the flame ones)
They are 2 individually sealed boxes glued together and wrapped in leather or something so it's like having 2 sealed boxes.

I have no idea what it's tuned at, but all the usually songs hit the hardest (six twelves, 143, like a g6, toot it and boot it)

As you can see by the current EQ settings, the bass isn't completely out of tune.
40Hz is flat, 80Hz is -1, and 100Hz is -2 (not that much taken away from the subs really)

As far as I can tell, the subs don't have any negative effect from removing anything above 100Hz. Seeing as how the head unit has the high pass filter at 125Hz, I figured anything below that wouldn't be good for the highs, and it seems to work.

And as I said in the first post, even on the guy that helped me ground the RCA's cheap brand components, reducing the bass and turning the treble up in the EQ did wonders for the highs, and he had components.

I guess my question was answered: get a device with individual EQ's for the subs and front/rear?

The "DSP" I looked up from pioneer is $300. Not exactly what I call worth it for a daily driver system...

Bico Stereo - Pioneer DEQ-P8000

hmm, I just remembered I have this sony crossover.

XEC-500

Sounds like exactly what I need?


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## sqshoestring (Jun 19, 2007)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*

That crossover does what your HU is doing now. Most typical is to run 80Hz, unless your mids are weak and can't handle that bass then you turn them up higher. But that does not necessarily make it sound better it might sound worse. The smaller your mid typical to set it higher for less bass.

If you need a pile of EQ either you like it to sound weird or your install is not ideal. Both can happen, lol.

Right if you have HP on mids at 125 and your sub the same LP, then in the EQ only above 125 will affect mids/highs and only under 125 will affect subs. Most all HU the EQ is for everything. You need to level match the sub to the mid (each amp) then you can EQ beyond the xover point.


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## Bayboy (Dec 29, 2010)

*Re: head unit EQ - why does it effect all outputs? (ALL RCA's, & speakers on Head uni*

From what I remember, Audiobahn subwoofers tended to be rather peaky in medium to small sealed enclosures. Even a eq cut in between 80-160hz should affect the sub somewhat. A good sub/box combo IMO would allow a natural low end boost that can be cut in the 40hz range to reserve amp power as most juice is used down low. If you cut the eq in the upper bass and it does not really affect the subs, then I would steer towards a larger box or go ported. Exactly what model subs are they and in what size/type box? 

As for the Polks, that is odd that you need to boost the upper end so much. The must be very off-axis or the amp pushing them is rather weak. Also a steeper xover slope or higher xover point should help with power handling as their small size may not be able to handle 80hz @ 12db slope.

If you can live with what you have, fine. If not, then you might want to do some revamping before adding a DSP. Dual F/R eq's would be nice, but better xover points and slopes would be needed as well.


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