# Possible Upgrades beyond REW 5.1



## audioTesting (Feb 28, 2015)

This is posted after reviewing and using the latest REW 5.1 Windows and Java 8 combination.
This is a very nice software package...I would like it to even move forward by adding these possibilities
in the future:

1. Under Measurement/Make a measurement...can you add the option for an external source as compared
to your generated frequency sweep?

2. Under RTA...can you allow the RTA octave options to reach down to 2 hz (from the now ~15 hz)? Also can 
you add Peak Hold option to the Spectrum option?

3. Under SPL Meter...Logger of data...can you add L10,L50 and L90 options (or general Ln) for data logging files?

Best Regards and thanks to the software developer(s)!


----------



## robbo266317 (Sep 22, 2008)

I have moved your post to the REW forum where it will be more visible.

-Bill


----------



## JohnM (Apr 11, 2006)

1 and 2 are already on the list, I'll add 3.


----------



## subterFUSE (May 10, 2014)

How about in the EQ section, in Target Settings... I wish there were more Crossover slopes that could be modeled. Like 48 dB.


----------



## natehansen66 (Feb 20, 2011)

I've got a few requests myself so I might as well toss them here.

1.) 1st order lo and hi pass filters in EQ
2.) To add to the above 8th order target request, I'd like to have the ability to target various filter topologies like LR, BW, Horbach-Keele, etc with 1-8th or higher order. ARTA does this but I think you could do it better.


----------



## Talley (Dec 8, 2010)

I hope everyone is donating. I'm waiting on my tax refund so I can donate adequately. This software is amazing.


----------



## jtalden (Mar 12, 2009)

Good Suggestion. I've been meaning to do this again and just now took time to increase my contribution level. It's an amazing and well supported software package. Thanks JohnM and HTS.


----------



## JohnM (Apr 11, 2006)

Donations to the HTS website go to VerticalScope Inc these days, but appreciate the sentiment 



subterFUSE said:


> How about in the EQ section, in Target Settings... I wish there were more Crossover slopes that could be modeled. Like 48 dB.


That's on the list, although the crossover doesn't typically have a big impact on the filters as EQ is mostly in the regions outside the sloped parts of the crossover response.



natehansen66 said:


> 1.) 1st order lo and hi pass filters in EQ


OK



> 2.) To add to the above 8th order target request, I'd like to have the ability to target various filter topologies like LR, BW, Horbach-Keele, etc with 1-8th or higher order. ARTA does this but I think you could do it better.


I'm not sure I understand how/when these would be used in REW, can you expand a bit or post some links to explanations of what you are after?


----------



## natehansen66 (Feb 20, 2011)

JohnM said:


> I'm not sure I understand how/when these would be used in REW, can you expand a bit or post some links to explanations of what you are after?


First I just wanna say thanks for all the work you do here.

What I'm talking about is using the EQ section for active crossover design. Under Target Settings when you select Subwoofer we're basically presented with a low and hi pass option. It would be nice to have a "Speaker" option that allows hi and low pass filters to be generated for the target curve, with whatever filter topology we would like to use to the "n"th order. Playing with it now I realize the hi and low cutoff for the sub can be any frequency I want. My memory isn't what it used to be but it seems to me that that used to be capped at 300hz. Nice!

I guess all I'm really asking for then is having different filter types available with, say, 1-8th order slopes. I haven't looked into it closely but it looks like the 12dB/24dB currently available are Butterworth? In the work I do I'm usually using 6th and 8th order LR. It would be nice to be able to use the Target curve in conjunction with the PEQ to build a eq/crossover filter set that I can then plug into my DSP.


----------



## jtalden (Mar 12, 2009)

JohnM said:


> Donations to the HTS website go to VerticalScope Inc these days, but appreciate the sentiment
> 
> I wish I knew that. A lot of things escape me now at my age. Anyway, I just made up for it with a donation at RoomEQWizard.com. I just have to sell another old driver or 2 to make up for the additional expense.


----------



## JohnM (Apr 11, 2006)

natehansen66 said:


> I guess all I'm really asking for then is having different filter types available with, say, 1-8th order slopes. I haven't looked into it closely but it looks like the 12dB/24dB currently available are Butterworth? In the work I do I'm usually using 6th and 8th order LR. It would be nice to be able to use the Target curve in conjunction with the PEQ to build a eq/crossover filter set that I can then plug into my DSP.


Would that mean generating the required crossover filters as a set of biquad sections? I'm not averse to the idea, but I'm conscious there are already some comprehensive crossover generation programs (WinPCD, ACD, RePhase) so I'm not sure there's much I could contribute.


----------



## subterFUSE (May 10, 2014)

JohnM said:


> That's on the list, although the crossover doesn't typically have a big impact on the filters as EQ is mostly in the regions outside the sloped parts of the crossover response.




That's great news. I only just started experimenting with some steeper crossover slopes for my horn-loaded compression drivers. The compression drivers have a very steep natural rolloff on the low end, so I wanted to try modeling a steeper blend with the midbass. I have been using a house curve with the EQ section in REW to simulate 24dB slope curves very well, but trying a 36 or 48dB is more difficult.


----------



## natehansen66 (Feb 20, 2011)

JohnM said:


> Would that mean generating the required crossover filters as a set of biquad sections? I'm not averse to the idea, but I'm conscious there are already some comprehensive crossover generation programs (WinPCD, ACD, RePhase) so I'm not sure there's much I could contribute.


No I just want to generate the xo target with the target curve, then use the peq to establish the eq/xo. To do this we need more options other than 2nd/4th order BW currently available. The peq you have is sufficient (or will be with a 6dB hi and lo pass).


----------



## jtalden (Mar 12, 2009)

natehansen66 said:


> I just want to generate the xo target with the target curve, then use the peq to establish the eq/xo.


There is a relatively easy workaround using the 'rePhase' program. RePhase allows; L-R or Butterworth, HPF or LPF, in 6dB/octave steps at any freq you choose.

I just created an REW house curve for a Butterworth 1kHz 48dB/octave as an example. 

I can document the process if it will be helpful.


----------



## natehansen66 (Feb 20, 2011)

jtalden said:


> There is a relatively easy workaround using the 'rePhase' program. RePhase allows; L-R or Butterworth, HPF or LPF, in 6dB/octave steps at any freq you choose.
> 
> I just created an REW house curve for a Butterworth 1kHz 48dB/octave as an example.
> 
> I can document the process if it will be helpful.


Yeah thanks I've done that before. I was just thinking it would be nice to have that functionality built in.


----------



## subterFUSE (May 10, 2014)

jtalden said:


> I can document the process if it will be helpful.
> 
> View attachment 84737



Yes. I would love to learn how to build a house curve for a Linkwitz 24 dB crossover slope.


Sent from my iPhone using Tapatalk


----------



## jtalden (Mar 12, 2009)

Attached is a spreadsheet that will generate Butterworth and L-R filter orders easily. There are probably several other options on the web as well.

If you want to use rePhase I will document that method also. It is more flexible, but also little more complicated for this purpose. Let me know if you still want those instructions also.

View attachment Calc But-x and LR-2x SPL Responses.zip


----------



## subterFUSE (May 10, 2014)

jtalden said:


> Attached is a spreadsheet that will generate Butterworth and L-R filter orders easily. There are probably several other options on the web as well.
> 
> If you want to use rePhase I will document that method also. It is more flexible, but also little more complicated for this purpose. Let me know if you still want those instructions also.
> 
> View attachment 88130



Fantastic.

Yes I would also like to explore REPhase


Sent from my iPhone using Tapatalk


----------



## jtalden (Mar 12, 2009)

rePhase:
> Open rePhase.exe
> Select 'Linear-Phase Filters' tab
> Enter; 'type', 'shape', 'param', and 'freq' values desired and other settings as example below.










> Click on the 'directory' input area to change the directory to a good location and also enter your filename.
> Select 'generate' to create the file
> Close

REW:
> Open REW.exe
> File/Import Impulse Response/<path/filename>/Open
> My example freq response came in at about 83.5dB but we want the bandpass SPL to be at 0dB instead so enter an 'offset' of -83.5dB and select 'add to data'. At this point the plot should look as shown below.










> File/Export/Measurement as text/<path/filename>/Save
> Preferences/House Curve/Browse/<path/filename>/Open

The new house curve is now loaded.


----------



## subterFUSE (May 10, 2014)

AWESOME!!! Thanks so much.

I'll review this and try it out tomorrow.


----------



## crossrh (Jun 18, 2006)

"Donations to the HTS website go to VerticalScope Inc these days, but appreciate the sentiment"

Do donations to RoomEQWizard.com go to you, John? That was my intent a few months ago. Your perseverance, diligence, and commitment to our hobby/pastime should not go unrewarded.


----------



## JohnM (Apr 11, 2006)

They certainly do, thanks.


----------



## subterFUSE (May 10, 2014)

jtalden said:


> rePhase:
> > Open rePhase.exe
> > Select 'Linear-Phase Filters' tab
> > Enter; 'type', 'shape', 'param', and 'freq' values desired and other settings as example below.
> ...



Did this last night and it works great. I got the filter curve into REW after generating in REPhase.

A couple of questions:

Is there any reason to select Linear Phase Filter rather than Minimum Phase Filter in REPhase for generating the curve?

I also tried loading a previous house curve into REPhase, a curve with a downward tilt in the upper frequencies and a boost in the bass. I then added an HP filter and REPhase shows the chart with the original shape and the generated filter slope. But when I export and load that IR into REW, the curve reverts to a flat SPL in the passband. The original house curve shape is gone.

Pics:

1. Loaded a house curve into rePhase.










2. Applied LR highpass 24 @ 800.










3. Generate and load IR into REW. The shape of the passband curve is gone.










Is the any way to preserve the shape of a house curve passband and add the crossover filter to it?


Sent from my iPhone using Tapatalk


----------



## jtalden (Mar 12, 2009)

The REW house curve adjustments that are provided can be used to modify any house curve you input. 

If that does not provide enough control you can also enter your additional house curve adjustments via rePhase in the 'Paragraphic Gain EQ' tab as shown below with a 100Hz 5dB shelf filter added to a 1k low pass XO filter. Add as many filter adjustments as you like.


----------



## AudiocRaver (Jun 6, 2012)

I have often wished for an "Apply to Selected" button for adding offset to the data for several curves at once.

Another helpful button would be "Normalize selected to x.x dB at yyy.y Frequency," for instance to make a selected family of curves all cross at 80 dB at 1 kHz. It would have to work at the chosen smoothing value. But would be most useful if you could specify the smoothing as a third variable but have REW preserve all unsmoothed data so those curves could still have less smoothing applied if desired later on.


----------



## jtalden (Mar 12, 2009)

Somehow I missed your post till now:



subterFUSE said:


> Is there any reason to select Linear Phase Filter rather than Minimum Phase Filter in REPhase for generating the curve?


It makes no difference so long as you can create the SPL shape you want. The linear phase tab allows any slope for the filters while the minimum phase tab is a little more limited. The phase data is not used by REW so it doesn't matter whether it is linear, minimum or random phase. Use whichever tabs help to create the SPL shape of choice. 



> I also tried loading a previous house curve into REPhase, a curve with a downward tilt in the upper frequencies and a boost in the bass. I then added an HP filter and REPhase shows the chart with the original shape and the generated filter slope. But when I export and load that IR into REW, the curve reverts to a flat SPL in the passband. The original house curve shape is gone...
> 
> Is there any way to preserve the shape of a house curve passband and add the crossover filter to it? passband. The original house curve shape is gone.


rePhase is generating filters, not importing and modifying them.


----------



## subterFUSE (May 10, 2014)

subterFUSE said:


> How about in the EQ section, in Target Settings... I wish there were more Crossover slopes that could be modeled. Like 48 dB.





JohnM said:


> That's on the list, although the crossover doesn't typically have a big impact on the filters as EQ is mostly in the regions outside the sloped parts of the crossover response.



My interest in having different types of crossovers available in the EQ section is not for the Auto EQ Filters, but rather for modeling my active crossover settings.

I have been using the EQ section, along with my house curve, to test out different crossover points in my DSP. 

Single-driver measurements are taken with different Xovers applied, and then viewed in the EQ section against the house curve. I then adjust the Target Level, Speaker Type, Crossover, Cutoff & Slope so that my house curve lays on top of the measurement as well as possible. This let's me see how my active crossover settings in the DSP affect the actual measured response. It also gives me a consistent target to compare left vs. right side drivers.

It would be nice if there were options to select Linkwitz slope, and if the slope could go to 36 and 48dB.



I spent quite a number of hours today attempting to use the ACD spreadsheets. I was able to export measurements from REW into the spreadsheets, but working with the spreadsheets is difficult.
Do we need to use smoothing on the response before exporting it to ACD? I tried with 1/6 octave smoothing, and it still was too difficult to get the charts to line up correctly. I got frustrated and quit eventually.
REW's interface is so much easier and more intuitive.


----------



## tvkartoffel (Feb 14, 2011)

Wishful thinking.

How about some collaboration with the guys from Jriver about some function to export/import filters from REW to Jriver. As is, there is no dedicated Jriver option in EQ and you cant export a text file that can be imported into Jriver. Id like to see that implemented, so that I dont have to manually type in all the filters i Jriver.

Id also like to see a possibility to export of filter impulse response as multichannel wav. It can only do mono and stereo so now i have to rely on external tool to assemble a multichannel file.

Thanks
Dan


----------

