# Room gain compensation vs PEQ



## littlejohn74

when is it better to use room gain compensation instead of PEQs? assuming one has enough PEQs, can't room gain be controlled with PEQs?

Having just got my first of hopefully 2 SB13u, i've left the room gain control alone, and done all my tuning using PEQs, but am wondering if I'd be better served EQing below 30Hz using Room Gain Compensation.


TIA.

Cheers
John


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## BeeMan458

littlejohn74 said:


> when is it better to use room gain compensation instead of PEQs? assuming one has enough PEQs, can't room gain be controlled with PEQs?
> 
> Having just got my first of hopefully 2 SB13u, i've left the room gain control alone, and done all my tuning using PEQs, but am wondering if I'd be better served EQing below 30Hz using Room Gain Compensation


I used XT32 w/SubEQ HT and used PEQ in an independent fashion for both subs as each subwoofer has an independent PEQ function and let REW aid me with the final solution.

(what is Room Gain Compensation)

Losing room gain, reads like a bad thing.


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## Ed Mullen

littlejohn74 said:


> when is it better to use room gain compensation instead of PEQs? assuming one has enough PEQs, can't room gain be controlled with PEQs?
> 
> Having just got my first of hopefully 2 SB13u, i've left the room gain control alone, and done all my tuning using PEQs, but am wondering if I'd be better served EQing below 30Hz using Room Gain Compensation.
> 
> 
> TIA.
> 
> Cheers
> John


Don't use Room Gain Comp with the SB13U - it's not needed. The roll-off slope of the SB13U is already slightly steeper than the theoretical maximum level of room gain (i.e., 12 dB/octave). Use the internal PEQs or an external EQ unit to control modal peaks.


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## littlejohn74

Ed Mullen said:


> Don't use Room Gain Comp with the SB13U - it's not needed. The roll-off slope of the SB13U is already slightly steeper than the theoretical maximum level of room gain (i.e., 12 dB/octave). Use the internal PEQs or an external EQ unit to control modal peaks.


Thanks Ed..

So back to the first question.. when would one use room gain comp?

cheers
John


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## Sonnie

Hi John...

Straight from the manual, which Ed probably wrote:

_*Room Gain Comp*
The Room Gain Comp (Compensation) Function allows the subwoofer to be set to compensate for the increase in low frequency sound based upon the size of the room if it is felt there is too much bass. Small rooms will have a greater increase in low frequency sound than larger rooms. There is no need to use this control unless it is felt there is too much low frequency energy being generated in the listening environment.

This function operates by setting a corner frequency of 40Hz (small size rooms), 31Hz (medium size rooms), 25Hz (large size rooms) or Disabled (no compensation), and allows a target slope of either 6 dB per octave (first order) or 12 dB per octave (second order) roll off from the selected corner frequency. This has the effect of attenuating the lower frequencies below the selected corner frequency at a rate commensurate with the selected slope.

_Basically, if you have ported sub in a room and have no equalization (such as Audyssey XT32), room boundary gain could create too much of an increase in output at lower frequencies, which the room gain comp can filter out. Naturally this is all dependent on the size of the room and where the sub is located. In many cases, particularly in smaller rooms, there is limited placement options and the sub is stuck in the corner. This could very well be where RGC could come in handy. It isn't much different from an infrasonic filter, other than it has options for higher corner frequencies.


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## littlejohn74

Sonnie said:


> Hi John...
> 
> Straight from the manual, which Ed probably wrote:
> 
> _*Room Gain Comp*
> The Room Gain Comp (Compensation) Function allows the subwoofer to be set to compensate for the increase in low frequency sound based upon the size of the room if it is felt there is too much bass. Small rooms will have a greater increase in low frequency sound than larger rooms. There is no need to use this control unless it is felt there is too much low frequency energy being generated in the listening environment.
> 
> This function operates by setting a corner frequency of 40Hz (small size rooms), 31Hz (medium size rooms), 25Hz (large size rooms) or Disabled (no compensation), and allows a target slope of either 6 dB per octave (first order) or 12 dB per octave (second order) roll off from the selected corner frequency. This has the effect of attenuating the lower frequencies below the selected corner frequency at a rate commensurate with the selected slope.
> 
> _Basically, if you have ported sub in a room and have no equalization (such as Audyssey XT32), room boundary gain could create too much of an increase in output at lower frequencies, which the room gain comp can filter out. Naturally this is all dependent on the size of the room and where the sub is located. In many cases, particularly in smaller rooms, there is limited placement options and the sub is stuck in the corner. This could very well be where RGC could come in handy. It isn't much different from an infrasonic filter, other than it has options for higher corner frequencies.



Thanks Sonnie, 

I read that section of the manual, which is what lead me to question RGC vs PEQ. So basically, if you have a ported sub with no or limited EQ capability, the RGC is the ticket.
Which is what I thought, but was after further clarification in case I was missing something.

Cheers,
John


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## Sonnie

Yes... provided you need it, it can certainly be the ticket. :T


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## fokakis1

Sonnie said:


> Yes... provided you need it, it can certainly be the ticket. :T


At the frequencies you listed, a 6-12 dB/octave slope applied to a ported sub would essentially make the roll off look like a sealed sub. I see the OP has a SB though.


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## Sonnie

Yeah... which is why Ed advised him not to use it with his sub... there should be no reason for him to need it. I guess if he was in a 10' x 12' completely sealed room, it could perhaps be needed, but he likely would have never bought that sub for that kind of room, unless he is like me and just likes to be punished by the sub monsters. In that case, make it a pair! :sarcastic:


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## BeeMan458

There are sub monsters?

...:scratch:

Oh please, punish me.

...

(are you surviving the rains and tornadoes Sonnie? my gosh you guys are getting beat up)


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## littlejohn74

Sonnie said:


> there should be no reason for him to need it. I guess if he was in a 10' x 12' completely sealed room, it could perhaps be needed, but he likely would have never bought that sub for that kind of room, unless he is like me and just like to be punished by the sub monsters. I that case, make it a pair! :sarcastic:


hmmmm... that is in fact my HT room:bigsmile::bigsmile::bigsmile:

Well... its a tad larger. 4.5mx3.5m


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## beyond 1000

I use the PEQs on my PB13 Ultra and leave the RGC alone. I shape my sub to the room not limit it. This is why I got SVS's mega-sub. :sn:


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## Televue101

Sonnie said:


> Hi John...
> 
> Straight from the manual, which Ed probably wrote:
> 
> _*Room Gain Comp*
> The Room Gain Comp (Compensation) Function allows the subwoofer to be set to compensate for the increase in low frequency sound based upon the size of the room if it is felt there is too much bass. Small rooms will have a greater increase in low frequency sound than larger rooms. There is no need to use this control unless it is felt there is too much low frequency energy being generated in the listening environment.
> 
> This function operates by setting a corner frequency of 40Hz (small size rooms), 31Hz (medium size rooms), 25Hz (large size rooms) or Disabled (no compensation), and allows a target slope of either 6 dB per octave (first order) or 12 dB per octave (second order) roll off from the selected corner frequency. This has the effect of attenuating the lower frequencies below the selected corner frequency at a rate commensurate with the selected slope._
> 
> Basically, if you have ported sub in a room and have no equalization (such as Audyssey XT32), room boundary gain could create too much of an increase in output at lower frequencies, which the room gain comp can filter out. Naturally this is all dependent on the size of the room and where the sub is located. In many cases, particularly in smaller rooms, there is limited placement options and the sub is stuck in the corner. This could very well be where RGC could come in handy. It isn't much different from an infrasonic filter, other than it has options for higher corner frequencies.


I don't understand this? If you don't feel the bass what is the point of even having a sub.


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