# REW Auto EQ Questions



## pdxrealtor (Jun 30, 2013)

Hi- Can someone explain not what these settings are for, but how one would set them up for a particular situation? 

I am using a Pioneer AVR crossed at 80 hz. A mini DSP for sub eq. 

It appears REW, under the target settings, wants you to shape the same settings your AVR would be sending out to the subs so REW can generate a matching set of filters and slopes. Easy enough I think. 

Subwoofer
24db/octave crossover
80 cutoff
24db/octave LF Slope

This is where I start to not understand how to plug in the numbers, or what numbers to plug in 

LF Cutoff. default is 10, but isn't this handled by my subs amp? 

LF Rise start - same as above- isn't this handled by the sub amp? 

LF Rise End - same as above - 

LF Rise slope - really lost on this one. 1.8 db/octave? How do I know the correct settings for this? 

All the same questions for HF Fall, FH Fall slope. 

Under Filter Tasks there is the match range- I understand this is the range REW will generate filters for, but how should I select the range? From subs max low output capability to AVR crossover or 80Hz? 

Individual max and overall max boost I understand completely. Same as flatness target. 

I did read the help page specific to this section.... but still could use some guidance. 

Sorry if these are dumb questions....


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## JohnM (Apr 11, 2006)

LF Slope and cutoff should reflect the capabilities of the subwoofer, the slope will depend on the enclosure (ported or sealed), the cutoff on the driver size and enclosure/port tuning.

The LF rise/HF fall controls are provided to allow 'house curve' adjustments to the overall target shape, so if (for example) you find the bass to sound more pleasing if it rises at low frequencies you can adjust the LF rise start/end to set the range over which you would like to see that rise and the slope to control how steep the rise is. It is a subjective setting, try setting the slope to zero to start with.

For the match range, for a sub there is no point going very far above the crossover frequency or below the point the natural response drops off. REW will not generate any filters at frequencies lower than the point the response drops and stays below the target (a little over 30 Hz for the plot you attached).

P.S. Better setting the frequency axis to log rather than linear, click the button third from the right just above the graph.


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## pdxrealtor (Jun 30, 2013)

Thank you for your reply. I am just sitting down to take measurements. 

I have ported subs, PSA xv line. Tuning is, I think, 18 hz, but there is some room gain to be had .... possibly. Would that be a 24 or 12db roll off? I did some reading and came to the conclusion it should match what your receiver is putting out. 

Re: match range. I think I understand what you're saying, but it brings up another question. What should the target level be set at? I am assuming that if you setup REW with the SPL tools to 80db that the target should be 80 db. Am I correct in my assumption? 


I took a few last night and they were off from my past measures. I re-set preferences and they were back to past measure results. 

Is it possible something in the preferences tab was out of whack, causing measurements to show differently on the graph? 

Thanks for the reminder on the graph setting. Much appreciated. It's been a month since I measured and a person forgets a lot if not done on a regular basis.


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