Using Room EQ Wizard (REW) to measure FR

[bluseminole]

Here's the sub graph:
Sub eq graph.jpg

I haven't messed around with the filter settings yet....I was pretty proud that I was able to even get the graph to work! "Baby steps....baby steps.."

I'll take a stab at them in the next few days though, I promise.

EDIT: BTW, placement of the sub is final. I can't move it....really....I can't. Check out my gallery, you'll see what I mean. The room is just awful, and the sub is quite big.

EDIT #2: Subwoofer to main speaker crossover was set at 80Hz

EDIT #3: I replaced the graph with one that tested the sub by itself. The dotted line represents my first foray into the Parametric EQ settings.

[sterryo]

EDIT: BTW, placement of the sub is final. I can't move it....really....I can't. Check out my gallery, you'll see what I mean. The room is just awful, and the sub is quite big.

looked at your gallery photos and I don't quite understand why you have no other placement capabilities?
Subs don't require being in the front, behind the seating or next to seating is recommended by Hsu Research.... along the back wall is good also.

I have a pair of a2-300 mid wall on side of theater

[bluseminole]

Originally Posted by sterryo

looked at your gallery photos and I don't quite understand why you have no other placement capabilities?
Subs don't require being in the front, behind the seating or next to seating is recommended by Hsu Research.... along the back wall is good also.

I have a pair of a2-300 mid wall on side of theater

No open wall space! Where would you suggest I try it? There's not enough room behind the recliner and I can't put it in front of the right speaker along that wall without interfering with that speaker. If there's something I've missed, I'm all ears!

BTW, nice BR player!

[sterryo]

Originally Posted by bluseminole

No open wall space! Where would you suggest I try it? There's not enough room behind the recliner and I can't put it in front of the right speaker along that wall without interfering with that speaker. If there's something I've missed, I'm all ears!

BTW, nice BR player!

since the pictures only show view from front i can only guess at the rest, perhaps next to recliner instead of behind it?
and thx for the compliment, I need to update my theater pics as I have really changed things down there, but will wait till i finish my sub risers and i also decided to get rid of my fugly home built stand and i am to build a cabinet into the wall underneath the steps

[bluseminole]

Originally Posted by sterryo

since the pictures only show view from front i can only guess at the rest, perhaps next to recliner instead of behind it?
and thx for the compliment, I need to update my theater pics as I have really changed things down there, but will wait till i finish my sub risers and i also decided to get rid of my fugly home built stand and i am to build a cabinet into the wall underneath the steps

Whoops, my bad! I have uploaded new pics of my setup since it's changed, but I forgot to put them in my gallery....I simply put them in a thread!

[kingofgrills]

Originally Posted by bluseminole

No open wall space! Where would you suggest I try it? There's not enough room behind the recliner and I can't put it in front of the right speaker along that wall without interfering with that speaker. If there's something I've missed, I'm all ears!

BTW, nice BR player!

At a minimum I would suggest switching the placement of your sub and your components. That will at least move the sub a little bit out of the corner to reduce some room loading from your bass response.

[Johk]

Just redid the soundcard calibration...

Here are the new curves...

With Audyssey


Without Audyssey


Still see a boost at ~17 Hz for the Audyssey curve... and like Forsberg pointed out, the 30-50 Hz region is a bit hot...

[jomari]

AHA! why didnt i see this thread!?!?

stimpson and fosberg... you dirty rascals! hehehe...

i have to start this thread from the top then...

from what i see, looking good buddies!

[Fors*]

Originally Posted by jomari

AHA! why didnt i see this thread!?!?

stimpson and fosberg... you dirty rascals! hehehe...

i have to start this thread from the top then...

from what i see, looking good buddies!

Thanks jomari, but I have to say I am following the lead of Stimspon JCat on this one. Without his help, I would never have been able to figure out how to set up REW. But I learned a lot and I guess thats what important. But I love this thread, as it has taught me quite a bit already!

[StimpsonJCat]

Originally Posted by jomari

AHA! why didnt i see this thread!?!?

stimpson and fosberg... you dirty rascals! hehehe...

i have to start this thread from the top then...

from what i see, looking good buddies!

Thanks. We are trying to learn as we go and any insight you can add is welcome.

[StimpsonJCat]

Originally Posted by Johk

Just redid the soundcard calibration...

Here are the new curves...

Still see a boost at ~17 Hz for the Audyssey curve... and like Forsberg pointed out, the 30-50 Hz region is a bit hot...

Those graphs look better! I think you have a similar issue with Audyssey not detecting your subs natural roll off. Otherwise I think it looks pretty good. You could fix this with the eQ.2 and get back a lot of your headroom.

[Fors*]

Originally Posted by Johk

Just redid the soundcard calibration...

Here are the new curves...

With Audyssey


Without Audyssey


Still see a boost at ~17 Hz for the Audyssey curve... and like Forsberg pointed out, the 30-50 Hz region is a bit hot...

It does look like Audyssey helped to cool things off a bit in the 30-50Hz region. Like StimsponJCat stated, that does look better, but perhaps the EQ2 is in your future to tame the roll off?

[Johk]

Originally Posted by StimpsonJCat

Those graphs look better! I think you have a similar issue with Audyssey not detecting your subs natural roll off. Otherwise I think it looks pretty good. You could fix this with the eQ.2 and get back a lot of your headroom.

Originally Posted by forsberg21

It does look like Audyssey helped to cool things off a bit in the 30-50Hz region. Like StimsponJCat stated, that does look better, but perhaps the EQ2 is in your future to tame the roll off?

I tried during the weekend to fix this with the PEQ on the sub and no luck the PEQ on the sub starts at 20 Hz and only cuts (which is not a bad thing but it didn't help me!).

I also tried setting the subsonic filter on the sub at 25 Hz instead of 20 Hz (settings are 25Hz, 20Hz, 16Hz, or 12Hz) but from what I could see the subsonic filter only appeared to change the output level (dB).

Also the EQ on my receiver is not available for the sub... Therefore like you guys said I'm probably gonna have to get an separate EQ.

Now I'm wondering if I should get the EQ.2 (100$ US) or the Behringer DSP1124P (130$ CDN) (I would like to get the SVS AS-EQ1 Subwoofer EQ but at 899$, it's a bit pricey )... The Behringer seems to have more bands but also looks a bit more complicated since it's not designed for HT but rater for studio, live applications.

Anyway I'm currently looking to get some info about duties for shipping the EQ.2 to Canada.

Update: Just spoke with a representative of eD and for 25$ the duties were included (standard shipping to Canada was free but with unknown duty costs, which is bad since one time I paid 60$ for a camera case that was worth 25$). So I ordered one up today! I hope it will allow me to correct the peak...

[StimpsonJCat]

Originally Posted by bluseminole

Here's the sub graph:

I haven't messed around with the filter settings yet....I was pretty proud that I was able to even get the graph to work! "Baby steps....baby steps.."

I'll take a stab at them in the next few days though, I promise.

EDIT: BTW, placement of the sub is final. I can't move it....really....I can't. Check out my gallery, you'll see what I mean. The room is just awful, and the sub is quite big.

EDIT #2: Subwoofer to main speaker crossover was set at 80Hz

EDIT #3: I replaced the graph with one that tested the sub by itself. The dotted line represents my first foray into the Parametric EQ settings.

First off good job getting things up and running with REW. It can be a pain to setup, but once you have it working it won't be hard to take new measurements. Thanks for contributing to this thread.

How many filters did REW setup? I would discount any with only a few dbs (<4) This will at least give you an idea of how many EQ bands it would take to get that dotted line FR.

Bummer about the placement issue. I'm pretty much stuck with mine as well. But, if you don't get rid of that null with placement you might just have to live with it. You could try to boost it with an EQ band, but often it won't make a difference. And even if it does you will lose head room in the process.

I want to measure with the Mains + Sub next and play with the crossover. I'm not sure when I will get to this, but I would like to see how it looks. I also want to play with the other features of REW.

[bluseminole]

Originally Posted by StimpsonJCat

First off good job getting things up and running with REW. It can be a pain to setup, but once you have it working it won't be hard to take new measurements. Thanks for contributing to this thread.

How many filters did REW setup? I would discount any with only a few dbs (<4) This will at least give you an idea of how many EQ bands it would take to get that dotted line FR.

Bummer about the placement issue. I'm pretty much stuck with mine as well. But, if you don't get rid of that null with placement you might just have to live with it. You could try to boost it with an EQ band, but often it won't make a difference. And even if it does you will lose head room in the process.

I want to measure with the Mains + Sub next and play with the crossover. I'm not sure when I will get to this, but I would like to see how it looks. I also want to play with the other features of REW.

Here's the graph of the sub response (solid line) and the predicted effect of the EQ filters automated by REW (dotted line) plotted against the target level (solid blue line, 77.1 dB....I guess I ran the test a tad hot ):

Sub Eq graph with auto filters.jpg

Here's my second shot at adding some manual filters. I went on the assumption that my limit will be 12 bands of EQ, because if I were to purchase something, it would likely be the Behringer DSP1124:

Sub Eq graph with manual filters.jpg

[StimpsonJCat]

Originally Posted by bluseminole

Here's the graph of the sub response (solid line) and the predicted effect of the EQ filters automated by REW (dotted line) plotted against the target level (solid blue line, 77.1 dB....I guess I ran the test a tad hot ):

Here's my second shot at adding some manual filters. I went on the assumption that my limit will be 12 bands of EQ, because if I were to purchase something, it would likely be the Behringer DSP1124:

I would be careful using a EQ filter to boost. If it really does boost you will lose headroom, but often you won't be able to actually boost a null.

I doubt you would ever need 12 bands. Take a look at this great post from HTS.

He shows how to reduce the number of filters needed (and which are not even really needed). I've read through a few peoples threads and they start out using a lot of bands, but in the end they get the best sound with only a few. Also he talks about setting up the target curve for the best starting point of adding filters.

Also, take a look at his discussion of house curves. I used a house curve, but with limited EQ bands I didn't try for the hard-knee house curve he talks about. It is an interesting read.

[sterryo]

Originally Posted by StimpsonJCat

I would be careful using a EQ filter to boost. If it really does boost you will lose headroom, but often you won't be able to actually boost a null.

I doubt you would ever need 12 bands. Take a look at this great post from HTS.

He shows how to reduce the number of filters needed (and which are not even really needed). I've read through a few peoples threads and they start out using a lot of bands, but in the end they get the best sound with only a few. Also he talks about setting up the target curve for the best starting point of adding filters.

Also, take a look at his discussion of house curves. I used a house curve, but with limited EQ bands I didn't try for the hard-knee house curve he talks about. It is an interesting read.

+1 more isn't always better, especially be careful about boosting frequencies..

[bluseminole]

Those are great articles, thanks for the advice. I'm playing with SOO many of the EQ filter settings now, trying them out at different target levels, different house curves (variations on the hard knee curve values he provided for his setup), and different levels of smoothing. Right now I'm trying to get something that looks reasonably pretty with four or fewer filters, none of which have a bandwidth lower than 6 (1/10th octave).

When I have something actually post-worthy instead of the myriad hypothetical graphs, I'll of course post it, but right now I'm blown away by the options!

I do have a question though: The target level isn't all that important is it? For instance, if I can best match the target curve when it's set to 82dB, I should do that, because the whole response can be adjusted up or down by adjusting the gain on the sub or the levels in the pre/pro, correct? In other words, setting a target of 82dB is pretty much saying, "the sub is 7dB too high?"

[StimpsonJCat]

Originally Posted by bluseminole

Those are great articles, thanks for the advice. I'm playing with SOO many of the EQ filter settings now, trying them out at different target levels, different house curves (variations on the hard knee curve values he provided for his setup), and different levels of smoothing. Right now I'm trying to get something that looks reasonably pretty with four or fewer filters, none of which have a bandwidth lower than 6 (1/10th octave).

When I have something actually post-worthy instead of the myriad hypothetical graphs, I'll of course post it, but right now I'm blown away by the options!

I do have a question though: The target level isn't all that important is it? For instance, if I can best match the target curve when it's set to 82dB, I should do that, because the whole response can be adjusted up or down by adjusting the gain on the sub or the levels in the pre/pro, correct? In other words, setting a target of 82dB is pretty much saying, "the sub is 7dB too high?"

Correct. For testing 75 db is a good level to run the measurements, but after that you can adjust the FR up and down or the target curve up and down as well. Then you can find the best starting point for calculating the filters. So, if you place the target curve in the right spot you will need less filters. But after setting up an EQ you can set the sub level anywhere you like it. You just want the FR to be lined up with the target curve you prefer.

I'm glad you are trying out the different target curve types. Everyone wants to achieve the best sound for them and one curve might fit what you are looking for better than another. In the end it doesn't matter what all these graphs say, you should let your ears be the judge.

Thanks for sharing your experience in this thread.