JRiver and PEQ Settings

[iamimdoc]

I am starting to look at room EQ.  Pretty complicated

 

System is large panel speakers with SVS sub for extreme low end only.  Sub is driven independently of panel speakers (I have 2 sets of preamp outs -> 1 to sub, 1 to panels).  I am trying to get sub setup.  Sub has up to 3 PEQ filters that can be used

 

I have a set of measurements from REW (done by my dealer) that suggest 10 PEQ filters would be more useful

 

I use JRiver which allows one to enter infinite PEQ filters

 

Would correct setup be to

Deactivate PEQ Filters in the Sub and Implement them in J River as a starting point?

 

thanks

 

 

 

[pompon]

It's the idea.

 

REW can generale auto-eq.

You just have to add this EQ (PEQ) into j-river.

[iamimdoc]

Thanks

 

If one placedPEQ filters in JRiver, how could you retest with REW?

 

The input for test tones from REW would be on preamp input 1, but JRiver would be on preamp input 2.  Thus REW testing would never see/be aware of the PEQ filter effects placed in JRiver.

 

thanks

 

 

[jjkale]

I believe if the JRiver WDM driver is installed on your machine, REW will measure the results of JRiver DSP.

I have verified this by experimenting with my system...making a dsp input and seeing the change in REW measurements.

The driver is available somewhere in the JRiver options.  There are instructions on the JRiver wiki.

Good weekend.

[Fitzcaraldo215]

4 hours ago, iamimdoc said:

Thanks

 

If one placedPEQ filters in JRiver, how could you retest with REW?

 

The input for test tones from REW would be on preamp input 1, but JRiver would be on preamp input 2.  Thus REW testing would never see/be aware of the PEQ filter effects placed in JRiver.

 

thanks

 

 

It sounds like you have a trust issue with Dirac.

 

I think cascading filters from one software and acoustic measurement environment to another different one, as in PEQ based on WDM in addition to Dirac, is not a good idea conceptually or at run-time in playback.  If Dirac's measured and calibrated filters based on its target curve are not to your liking, you can modify the Dirac target curve and use that single filter set for playback..

 

You can measure Dirac response with WDM, but there will be differences between Dirac's  and WDMs  measurements due to single vs. multipoint spatial averaging, time windowing, etc. So, which is right?  I personally favor the multipoint, spatially averaged measurements of Dirac, and I have been perfectly satisfied with an unmodified Dirac default target curve, which is based on very good scientific research.

 

 

[iamimdoc]

Thanks jjkale as this looks to be what I need.  

 

I am brand new to this and am using this  to educate myself as well as hopefully improve sound

 

Back to a more basic question:, 

 

to implement peq filters in Jriver, one needs only to

-click on the peq filters tick box

-enter the filters 

-save the information 

 

Or does something else need to be configured...

 

if above is correct,

-does it make a difference as to order filters are entered? 

-Are there guideline as to q values or level of filters not to exceed?

 

Thanks to all for help, suggestions 

[jjkale]

iam,

You have the configuration filter steps correct.

The order of the first three boxes in dsp studio cannot be changed, but after that the user can drag the other boxes into their own personal order.

If you use bass management, I recommend the peq(s) prior to bm.  Technique only.

Within the peq boxes, the different filters operate in order, but that shouldn't matter, I don't think.  Having an organization you can understand is more important.

There are many suggestions for q levels and gain.  Many people recommend only eq'ing up to the Schroeder freq (look it up!), or maybe only to the 1-2.5kHz range.  Personal preference.   The explanation is too cumbersome for this forum.

Technique only:  limit gain to 5-6 dB.  At higher freqs, broader adjustment is better.  Concentrate on lowering the peaks, rather than increasing gains on the nulls.

Again, technique only:  accomplish all your dsp in JRiver.  Don't use the sub controls.  JRiver is very precise.

A very robust CPU will help.

An excellent reference is "Sound Reproduction" by Floyd Toole.  Toole is the man for this stuff.  You can also Google search for articles by Olive and Welti.

Although the previous poster references a lack of trust in Dirac, I don't see that you made any reference to Dirac.

If you can become proficient in using REW and measuring you can achieve better results than with Dirac.  You can also save yourself approximately $750 (multichannel version).   Dirac is a fine product but it has its weaknesses, particularly in the area of bass management.

You can easily make multiple measurements on your own with REW and average or make your own decisions on how to use dsp based on positions in your listening room.  It will take time and patience, like any hobby, but can be done.  It's not rocket science.

Good weekend,

jjk

[iamimdoc]

Thanks for help.  Got it working I think (well, see below ).  This is mainly a learning experience for me at this point. 

 

Input is into left channel of speaker only.

mic at listening position 

Possible issue is I am using old radio snack sound level meter with behringer A TO D gadget for input and output to laptop.  Per REW website this should work at lower frequencies.  There is no calibration for mic so absolute levels are suspect I presume. 

 

As a first try I put a PEQ filter in Jriver at 50 Hz, -20 db, q of 1. Ran a measurement 

I replaced this with another filter except -10 db. Ran a measurement.

 

I got a sharp negative frequency response spike with magnitude expected BUT at 37.5 Hz for both PEQ's.

 

Could someone opine as to why this might be happening as I was expecting spike at 50 Hz? 

 

in future, I intend to try right channel and then mono to stereo connector to feed both channels to see if some strange room reaction 

 

Thanks.