# Graph Results REW EQ vs Audyssey. Does it matter?



## Papcody

First post and use of REW, so please feel free to point out any mistakes 

I have two sealed DIY Dayton 18" subs that I'm trying to get a hold of. They're powered off an EP4000, one off each channel. I'm running an Onkyo with dual preouts an X32. The room is about 3000 cuft. dedicated theater room. I have some bass "chunk style" corner traps and a couple of first reflection panels 3" thick. 

Measurements taken with a UMIK-1. I have a miniDSP on the way so i'm just now learning about all of this.

I have always heard that sealed subs roll off pretty hard below 25 hrtz and EQ would be good to bump this. Here are the results of using Audyssey vs None, and then Audyssey vs REW EQ. Note that the REW EQ is projected because I don't have the minidsp yet. 

AUDYSSEY vs RAW Sweep








REW EQ vs RAW Sweep








AUDYSSEY vs REW EQ








It looks like the EQ built into REW isn't going to do much better that Audyssey xt32 did.

Am I missing anything or is there a better filter or EQ I could use on the sealed subs to get a little more slam out of them?


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## blitzer

Looks like Audyssey did a good job and you have a great room and have arranged your subs well. You can still use the MiniDSP to fine tune to your tastes as a flat response can be very boring for movies. You can add your own house curve with a shelf filter.


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## Papcody

Thanks for the reply Brent. My setup is mainly for movies. So I'm really looking to add as much punch as possible in the low end without sounding muddy. I'm trying to do some reading on house curves. Is this just basically bumping up the low frequencies from say 15 to 80? 

I'm also a little confused on what volume level to take my readings at in REW. Should I turn my receiver up to reference (82)? Should I turn the gain up on my amp to the subs? Right now the dials on the Ep4000 are at about half way. 

There must be a rule of thumb I've missed on how to handle subwoofer volume when it relates to gain vs the AVR sub level. When I first ran audyssey i had sub out on the Avr at 0 and turned up the gain knobs on the EP4000 amp until I hit the requested 75db (which was about half way). Funny thing is after audyssey ran and did its thing it turned them down in the AVR -4db. 

Stupid question alert..... If the sub is crossed at 80, what would a shelf filter do that just turning up the gain on the amp wouldn't? Right now if I turned up the gain it just gets muddy.


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## Wayne A. Pflughaupt

Papcody said:


> I'm trying to do some reading on house curves. Is this just basically bumping up the low frequencies from say 15 to 80?


Basically, but it would probably sound better to stop (shelve or flatten) the rise somewhere between 25-30 Hz, depending on your personal tastes and your room.




> I'm also a little confused on what volume level to take my readings at in REW. Should I turn my receiver up to reference (82)?


REW’s recommended 75 dB for measurements is fine. :T




> There must be a rule of thumb I've missed on how to handle subwoofer volume when it relates to gain vs the AVR sub level.


I believe a rough rule of thumb is to run the sub 10 dB hotter than the mains. Not a bad place to start, but if it doesn’t sound balanced to your, feel free to adjust the sub level as needed.




> Stupid question alert..... If the sub is crossed at 80, what would a shelf filter do that just turning up the gain on the amp wouldn't?


Sorry, you lost me there. What do you mean by “do that?”




> Should I turn the gain up on my amp to the subs? Right now the dials on the Ep4000 are at about half way.


It amounts to the same thing in the end. Just don’t turn up the subwoofer send so much that it makes the amp’s inputs clip.

Regards, 
Wayne


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## blitzer

Papcody said:


> Thanks for the reply Brent. My setup is mainly for movies. So I'm really looking to add as much punch as possible in the low end without sounding muddy. I'm trying to do some reading on house curves. Is this just basically bumping up the low frequencies from say 15 to 80?
> 
> I'm also a little confused on what volume level to take my readings at in REW. Should I turn my receiver up to reference (82)? Should I turn the gain up on my amp to the subs? Right now the dials on the Ep4000 are at about half way.
> 
> There must be a rule of thumb I've missed on how to handle subwoofer volume when it relates to gain vs the AVR sub level. When I first ran audyssey i had sub out on the Avr at 0 and turned up the gain knobs on the EP4000 amp until I hit the requested 75db (which was about half way). Funny thing is after audyssey ran and did its thing it turned them down in the AVR -4db.
> 
> Stupid question alert..... If the sub is crossed at 80, what would a shelf filter do that just turning up the gain on the amp wouldn't? Right now if I turned up the gain it just gets muddy.


I have to admit that I have used the amp volume for a lazy house curve. But if you fart around with REW enough, you will most likely find that turning up the amp does not do the same thing as setting up the appropriate shelf filter and appropriate filters on top of that. Give it a shot - try both ways, see how the frequency response curve responds to simple EP4000 amp gain changes. You will most likely find that different frequencies are boosted more than others. This has been my experience. 

Audyssey is going to turn down/up the gain on the sub with the goal of getting the flattest response curve. Audyssey turns my sub down to -12db with my EP4000 set to anything above a 9 o'clock setting.

Take your readings at the sound level that you expect to use or want the flattest response curve(your reference level). If you always listen at low levels and want to tune for best sound at that volume - use a low level. If you want to tune for movies at a loud/reference SPL level, then tune at that level. The volume level you choose to equalize at makes a big difference - especially in the bass region and as you get louder. 

The curve is relative, so how high the curve is - is not of great concern as long as the sound is at your reference level. This is something that nobody explains well and confused me for a long time. People look for how the curve varies in DB from one frequency to another and not at how loud it is. 

BTW: Everything I know is based on my own personal experience, experiments, frustration with sub/REW/UMIK/MiniDSP/EP4000. YMMV


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## blitzer

Papcody said:


> I'm also a little confused on what volume level to take my readings at in REW. Should I turn my receiver up to reference (82)? Should I turn the gain up on my amp to the subs? Right now the dials on the Ep4000 are at about half way.


Forgot to mention, set the gain on the EP4000 so that Audyssey and/or MiniDSP don't have to mess with the response as much to get the flat curve. General ideal would be that Audyssey comes up with a 0DB setting for the sub.


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## Papcody

Thanks for the replies. I got my MiniDsp and 4 way adv plug in and have started playing around with it. Can you guys verify that i'm doing things correctly?

I have two sub outs on the Onkyo that are going into inputs one and two of the 2x4 balanced mini
I chopped up some XLR cables and used outputs 1 and 3 of the mini to the amp
Sound correct?

Is there a way to select "stereo" mode for subs in the Adv 4 way plug-in?

Looking at the screenshot below I have a couple of questions:









1) Do I use the first Parametric EQ block to load corrected REW files or the Output 1 and 3 blocks individually?
2) I notice when I click on the first Parametric EQ block it only says "Input 1 channel 1". What about input 2?
3) In the "system settings" tab do I select digital or analog?
4) Lastly, do I bypass all crossovers in the 4 way crossover block?

Any help would be greatly appreciated. Thanks!


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## GCG

this may be the blind leading the blind here so take this with a grain ...


I would recommend any two of the outputs (see #2 below).
Unless there is something unique about the Onkyo sub outs they should carry the same signal and you should only drive one of the inputs on the MiniDSP. On the 4-way you can only use one. It's designed purpose is primarily to form an active 3 or 4-way crossover for a full range speaker from a single pre-out. (The selection is in the Input Gain block BTW).
Analog
Yes (At least on the output channels you intend to use.)


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## Papcody

The onkyo has two outs so it can treat each sub independently via Audyssey xt32. 

Should I get a different plug in you think?

Another question on a different note, can I get a non-EQ'd measurement from REW into the MiniDSP? I'd like to tale my Audyssey corrected FR and tweak it a little in MiniDSP. The only way I can find to export it is if I use the EQ feature, which in turn changes it.


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## dwaleke

Here is a pretty good guide to setting up stereo subwoofers. I use the Advanced 2.1 plugin.

http://www.avsforum.com/t/1488457/tutorial-dual-sub-integration-using-the-minidsp


Which Onkyo are you using? You probably know this, but not all Onkyo receivers with XT32 have SubEQ. SubEQ is required to set level and delay separately between two subwoofers. You can do a bit of that with the Minidsp as well so it may not matter. After level and delay are set in the AVR it then EQs both subwoofers together as one.


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## Papcody

That guide is awesome!

My Onkyo is a 5009. I think I figured most out right now. I flattened the response out and then started playing around with the various peak and shelf filters. The peak is pretty self explanatory. I'm still getting the hang of the shelf. I just did a little 5db boost at 40 and 70 on this capture below with peak filters. It's fun to play around with it. I still have a lot of learning to do.. I did however figure out what frequency causes every sconce in the room to shake violently  Its pretty cool you can do it on the fly. There's a scene in Enders Game around an hour and a half in that will slam you in the face and rumble the room nicely. 

I'll try the house curve approach next time I link up.


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## GCG

Glad someone with Aud. experience chimed in (I'm a Pioneer MCACC guy). I've been buzz checking with REW, too. Nice tool, does bunches. 

One of my checks is the opening sequence Of Lord of the Rings - Fellowship where Isildur slices the fingers and ring off Sauron. I don't think I have the room right if I can't feel the shock wave that follows moving through me. If the blend isn't right, it'll show up nicely there as the freq sweeps down.

Nice FR BTW.


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