# house curve level matching question



## wilesone (Sep 8, 2008)

I am going to get a dsp1124 and have a couple of questions.

1. When do you level match your subs with this? Do you level match to your mains before you do any equalizing or after you've got a flat response? I would assume the latter. What if I use a house curve or hardknee house curve? I wouldnt think you could level match after applying the house curve without getting a completely inaccurate result.

2. With a house curve you are making the lower frequencies louder than everything else. So if everything is level matched at 75db then say you have a 8db house curve going then the bottom end will be 8db louder which means that frequency and every other frequency up to your crossover is boosted. Is this corrrect? The only cut you would actually be making is your shelving filter way up high in frequency. I know people do this and it's ok I'm just trying to understand things more clearly. Is putting that much eq boost a strain on your sub amp or does the amp not see it as all boost because of the shelving filter?

3. Are people generally using the same house curve for music and movies? Or is flat generally better for movies? 

4. I rarely watch movies louder than -15 on my reciever but I'll crank music at 0 and be in the other room or outside. Will this much difference be a problem when setting the input level or will it even out since the lfe in a movie is alot hotter than low bass in music? What if it was pipe organ or some other very bass heavy music?

I would really appreciate any help I could get with these questions. Thank you


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## Wayne A. Pflughaupt (Apr 13, 2006)

Welcome to the Forum, wilesone!

The BFD Guide has tips for setting the BFD’s input levels. Only, get the meter in the -10-12 dB range, not at clipping as the Guide says. It’s a good idea to leave some headroom.

The typically procedure is to equalize the subwoofer, then re-adjust your sub level afterwards. “House curve or not” is irrelevant.




> Is putting that much eq boost a strain on your sub amp or does the amp not see it as all boost because of the shelving filter?


 Any equalizing taxes headroom, doesn’t matter if it’s boosting or cutting. You have to have headroom to spare going in, or you shouldn’t equalize. 




> 3. Are people generally using the same house curve for music and movies? Or is flat generally better for movies?


Different people have different preferences. Experiment and discover what works for you. :T

Regards,
Wayne


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## wilesone (Sep 8, 2008)

Thanks Wayne. I just thought level matching after applying a housse curve would skew the measurement or blend with the mains since the lower frequencies would be louder and that would measure as such with pink noise. If this is not the case that is great. Is my thinking off that when measuring pink noise the lower frequencies would be louder and thus effect the reading on the spl meter? 

Thank you for all of your work on the house curve articles. You're articles and enthusiasm is the reason I'm so excited to try it out and your knowledge and willingness to share it and help others is very much appreciated.


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## wilesone (Sep 8, 2008)

I thought of another question. I apologize if it is a stupid one. Can I set a house curve without using a shelving filter way up high in frequency like brucek did or does one have to set that big cut wide bandwidth filter in order to get the basic house curve response to start with? 

I'm still having some trouble wrapping my brain around these concepts. If you set a deep cut filter around 400hz then wouldnt your sub already be much lower in volume than your mains at the crossover point? That seems like it wouldnt blend very well at all.

Wayne, do you have any input on my question number 4?

Please try to help me understand these concepts better since I really want to understand it and try to implement it into my system. Thank you.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hi wileson,


> Is my thinking off that when measuring pink noise the lower frequencies would be louder and thus effect the reading on the spl meter?


Without going into technical details, pink noise is essentially a flat signal across the frequency spectrum. However, the sub’s in-room response is not flat, it has peaks and depressions. Whatever frequency is peaking the loudest, that’s what will determine the dB figure you see on a SPL meter’s display.




> I thought of another question. I apologize if it is a stupid one. Can I set a house curve without using a shelving filter way up high in frequency like brucek did...


Sure, not a problem. The only real reason to use that shelving filter is if your unequalized response is so good to begin with that one or two filters will render it flat, in which case a shelving filter would be an easy way to get a house curve. 




> I'm still having some trouble wrapping my brain around these concepts. If you set a deep cut filter around 400hz then wouldnt your sub already be much lower in volume than your mains at the crossover point? That seems like it wouldnt blend very well at all.


_Any_ equalizing is going to affect the sub’s volume. That’s why you re-adjust its level after equalization.



> Wayne, do you have any input on my question number 4?


Wasn’t sure I got what you were asking in that question. If it’s about setting the BFD’s input level, I addressed that in my previous post:



Wayne A. Pflughaupt said:


> The BFD Guide has tips for setting the BFD’s input levels. Only, get the meter in the -10-12 dB range, not at clipping as the Guide says. It’s a good idea to leave some headroom.


As the BFD Guide indicates, just play the most bass-heavy program material you have, at the highest volume you’d ever play it, and adjust the receiver’s subwoofer level so that the BFD’s meter hits -10 dB pretty hard. That’ll leave you enough headroom in case you acquire a CD or movie in the future with bass that’s even more severe.

Hope this helps. :T

Regards,
Wayne


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