# Clipping BFD



## Mpray1983 (Jun 22, 2011)

Alright guys I have literally exhausted all avenues trying to deal with this clipping BFD. I have an:

integra 40.2 rca/XLR to BFD
BFD xlr to ep4000
Ep4000 to 2 dual opposed mfw's

I cannot seem to keep my BFD from clipping in the bathtub scene of inception and the pod emergence scene of WOTW in a few places at anything less than 75db.
My room has one sub in the corner at half volume on 1 channel and the other sub is at the bass of a hallway and is maxed out on channel 2. Both are level matched at 75db. I have tried everything from raising all my speakers 10db to raise my reference level to switching between -10db and +4db on the BFD. At -10 I clip the bFD and at +4 I clip the amp. My receiver while on the -10 setting is at -12 out of a possible -15. Output voltage on the integra is 200 mV with a Max of 4.6v on the RCA preout. 

Please let me know if anyone has any ideas as I have been working on this for 3 days.


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## kstich (Jul 24, 2008)

It would really help to know what your filter settings are in the BFD. 

What I suspect is a series of filters that provide gain to the input signal from your receiver may be the problem. If possible, I would recommend checking that first. I try to keep my BFD to no more than +3 dB of gain on any of the filters, with most being negative values. It is very easy to have a digital processor produce clipping when providing too much gain. 3 db is a 2x increase in voltage (I think, I am not sure if the BFD is voltage or power based, anyways). 10 db is a 10x increase in output. Its very easy to cause clipping using a few filters with high gains. 

Secondly, you may want to make sure any unused filters are set to manual and zeroed out.

Third, your amp is a -10 dB source, you should select that and deal with the clipping in the BFD. +4 is a higher voltage signal, which means the BFD internally lowers it to a point where it masks your real problem.


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## Mpray1983 (Jun 22, 2011)

I tried using no boost at all an it didnt work either. Here is where the problem lies. The sub on the right is at the beginning of two openings and needs to be cranked all the way. The sub In the corner is at half volume. Because of this I get no room to adjust after cutting my peaks because the only place left to level match the subs to speakers is in the receivers sub trim trim volume. My only option is to turn up the left sub's volume to level match but then my sub's aren't matched.


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## vann_d (Apr 7, 2009)

Select +4dB and turn down the gains on your ep4000 (amp is clipping, right?). Sounds like you have room to adjust there as one is set to 50% and one to 100%. You still have 50% of the gain control to play with.

It matters not that your receiver is a -10dB source, if it's putting out enough voltage to clip the -10dB setting then you need to use the +4dB setting.


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## Mpray1983 (Jun 22, 2011)

vann_d said:


> Select +4dB and turn down the gains on your ep4000 (amp is clipping, right?). Sounds like you have room to adjust there as one is set to 50% and one to 100%. You still have 50% of the gain control to play with.
> 
> It matters not that your receiver is a -10dB source, if it's putting out enough voltage to clip the -10dB setting then you need to use the +4dB setting.


The BFD clips on -10 and the amp clips on +4. If I turn down the gain on the amp then I have to turn up the receiver trim. I think this is happening because of the location


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## jtalden (Mar 12, 2009)

Mpray,
It's hard to imagine a situation where the SW location is could be the issue.

So, Hopefully you have revisited the basics several times.
> All 4 drivers are connected with the same polarity (battery test on SW's and also P-Amp connection wiring)
> Minimum nominal speaker impedence for the amp is 2 ohms (or 4 ohms if the amp is bridged)

Just a reminder because I sometimes find basic errors even after several reviews.


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## Mpray1983 (Jun 22, 2011)

I checked all of that. The sub is at the base of two hallways...these aren't small hallways either...8th wide and 11 ft high. I even swapped the subs location with each other. If I co-locate the subs then everything is fine but I am unable to do that due to WAF. Having the sub in this hallway location also put the sub at 180 phase. These aren't the first subs I have had in this location. They are just the first to use a pro amp.


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## Zeitgeist (Apr 4, 2009)

With an Integra, a BFD and an EP4000 that should be possible to get plenty of power without clippping.

I had to use the +4 setting on my BFD because the my Onkyo can easily put out high signal levels, but with +4 on the BFD that should be plenty if using an EP4000 bridged.

I can easily power a 21" Mal-X with power to spare with that setup. That should be overkill for a pair of MFWs.


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## vann_d (Apr 7, 2009)

Mpray1983 said:


> The BFD clips on -10 and the amp clips on +4. If I turn down the gain on the amp then I have to turn up the receiver trim. I think this is happening because of the location


Hmm, if your gain is set properly you will not clip the amp. I suggested turning down the gain because the amp is clipping. (+4dB setting) 

If you don't have enough output at this point I'm not sure what's wrong besides lack of output. You shouldn't have to turn receiver trim up. Have you verified all the dip switches on the amp are set correctly? People have been known to have problems setting these correctly.

It's hard to believe two dual opposed with a ep4000 can't keep up with your mains.


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## Mpray1983 (Jun 22, 2011)

Im using parallel so both of those switches 4 and 5 are to the right and the low cut filters are both turned off. Should I try using the clip limiter?


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## Mpray1983 (Jun 22, 2011)

Problem solved...It was the dipswitches. I had the low cut filter 50hz on. I feel stupid

Edit:

Nevermind I just tries war of the worlds and the BFD clipped. I'm trying +4 settings now


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## Mpray1983 (Jun 22, 2011)

+4 settings did not work either. I believe the sub is bottoming out which would make sense if they are just mfw-15's. Honestly I can't be too upset because there aren't many movies with that level of bass.


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## Mpray1983 (Jun 22, 2011)

Fixed it...I had a wire incorrect. Finally everything works good on the -10 setting and gain is up half way. I'm pretty sure I fried an ep4000 yesterday and I returned it and grabbed a QSC GX5. Do you guys think this should be fine or should I bring it back and get another EP4000?


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## Zeitgeist (Apr 4, 2009)

Mpray1983 said:


> Fixed it...I had a wire incorrect. Finally everything works good on the -10 setting and gain is up half way. I'm pretty sure I fried an ep4000 yesterday and I returned it and grabbed a QSC GX5. Do you guys think this should be fine or should I bring it back and get another EP4000?


The EP4000 (EP2500, etc) is pretty robust and has tested very well.


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## vann_d (Apr 7, 2009)

The ep has more power but if the qsc has enough for your subs then does it really matter?


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## Mpray1983 (Jun 22, 2011)

Do you think it was because of the wires being mismatched that I blew the amp. Basically it got really hot and started over heating. It would not stay on after without the breaker tripping.


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## vann_d (Apr 7, 2009)

How did you have it wired? Was something shorted?


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## Mpray1983 (Jun 22, 2011)

vann_d said:


> How did you have it wired? Was something shorted?


I had one driver wired backwards in a dual opposed.


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## Mpray1983 (Jun 22, 2011)

vann_d said:


> The ep has more power but if the qsc has enough for your subs then does it really matter?


Yes it powers them...but I would like to be able to upgrade and not have to buy a new amp. Plus the EP4000 is cheaper by $60. Another plus is the fact that testing has been done to figure out what the exact output of the EP4000 is. Also directions on a fan mod because this one is loud! I feel like I just answered my own question. 

What makes you say the EP4000 has more power...testing shows the ep4000 at 500 watts @ 8 ohms and the GX5 is the same.


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## vann_d (Apr 7, 2009)

I thought the EP had more in bridge mode than the GX...yeah just checked. The EP says it's 2 ohm stable and the GX does not. Thayt's a plus for the EP.

Sound like you had drivers in parallel instead of series...I would not think this would fry the EP. If you are hard clipping the amp maybe you could fry it.


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## Mpray1983 (Jun 22, 2011)

vann_d said:


> I thought the EP had more in bridge mode than the GX...yeah just checked. The EP says it's 2 ohm stable and the GX does not. Thayt's a plus for the EP.
> 
> Sound like you had drivers in parallel instead of series...I would not think this would fry the EP. If you are hard clipping the amp maybe you could fry it.


That must have been what it was...I had that ch. Twice the gain as the other. I was clipping a lot when I was trying to set it up in +4 studio mode.

I was running in series but 1 driver was wired backwards. So basically they were cancelling each other out. That was the reason for having the gain so high. I'm just happy that it is fixed.


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## vann_d (Apr 7, 2009)

Ahh, yeah. Well, glad you got it figured out.

50 Hz fpf + out of phase drivers = no woofage


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