[Nuance]

Thanks for posting your measurements.  Based on what I see I do highly recommend experimenting with other locations (the sub and your couch).  Placing the subwoofer near the center of the room has always made for difficult integration in my experience, as does placing the listening position there.  The bass response will just about always be the worst it can be if you're sitting in the center of the room.  It would be best to place the subwoofer near a side wall boundary, but not necessarily in the corner (corners are okay, though).  Try behind the LP to the left of the desk (near where the angled wall meets the back wall), or try the front right corner near.  Posting a couple other pictures so we can see the rest of the room would be helpful.

I recommend measuring how far your couch is from the front and back wall.  If it is close to the center of the room then it's time to bargain with the wife and move it back a bit.  Ideally you want to be around 1/3 the length of the room from either the front or the back wall.  In your case I'd recommend 2/3 from the front wall and 1/3 from the back wall.  I realize this may not be doable, but being near the center of the room will almost always produce a poor response.

[chargedmr2]

Nuance,

Thanks for the comments.  TJHUB has been helping me out via PM and I have made some good progress.  For now, the sub is no longer next to the couch.  After many (many) measures, I have located it between the two white chairs on the opposite side of the room near the windows.  I'm not sure this is the best location, but it's much better (Austin also recommended this spot).  I could hear the difference immediately.  The null/dip just under 30Hz is completely gone and the peaks in the 70-80Hz range have come down as well.  My wife isn't overjoyed about this new spot, since it displaced another end table that she really liked, but she's surprisingly agreeable and I think she will live   I might be able to move the couch back a little more, but I'm not sure I'll get noticeable improvements, though I will definitely check (I can only move back about 6" before crowding the desk behind it).  I'll be ordering a BFD DSP1124p this week, though it seems that they may have been discontinued?  Can't wait to see what I can do with some EQ applied.

[Nuance]

That's great news!  Your new location is ideal, as it's not directly in a corner but is along a boundary - very cool.  Do you mind posting measurements? 

I didn't realize the 1124p was discontinued.  They usually sell for $50 used, which is a bargain in my opinion.  Try to snatch a used one up if you can.  When it arrives I'd be happy to walk you through the input level setup with the receiver, not to mention anything else.  I am sure TJHUB would be more than happy to assist as well. 

You're well on your way to achieving a great blend and awesome bass!

[chargedmr2]

Nuance,

Here is the last measure that I took.  This is the sub only (mains disconnected), with the crossover set to 80Hz.  There is no smoothing applied.  Obviously not a good frequency response as is, but hopefully one that can now be tamed with some EQ (unlike my first measures).  Also, I need to measure with my mains running again to see what happens in the crossover region.  I'm hoping the nulls above 80Hz in the graph posted here will be less problematic once the mains are factored in--we'll see. 

[Gzerro]

On the EQ, you mentioned earlier in the thread you were running a Denon AVR, although not which model. Some Denon AVRs (4311 for sure, don't know about others), have an option to bypass Audessey to the left and right spreaker. For stereo sources this would only EQ the SUB, not the mains. I ran this way quite a while with good results. If you happen have the 4311, Audessey XT32 is quite good for subwoofer EQ.

Just something to try, since it may not cost you anything if your AVR has that function.

[chargedmr2]

Gzerro,

Thanks for the tip--I was wondering about that exact issue.  I was thinking that I could try out Audyssey for the sub only, but wasn't sure if/how that was possible.  Unfortunately, I have a lower line Denon AVR (3312) and it has XT, but not XT32.  I'll double check to see if there is a way to disable Audyssey settings for my mains.  In the end, the BFD is a reasonably priced EQ option, so that is what I'll plan to do for the long term solution. 

[rif]

I have a denon 2113ci.  I think DIRECT mode disables all processing and sends signal only to L/R (no subwoofer). PURE DIRECT is the same but turns off all video circuits. STEREO mode sends L/R and sub and applies processing (multieq and dynamic eq) unless you specifically go through some menus and turn it off.

Also keep in mind that the processing can normalize to a few curves - but the default is NOT flat.

[chargedmr2]

I have a denon 2113ci.  I think DIRECT mode disables all processing and sends signal only to L/R (no subwoofer). PURE DIRECT is the same but turns off all video circuits. STEREO mode sends L/R and sub and applies processing (multieq and dynamic eq) unless you specifically go through some menus and turn it off.

Also keep in mind that the processing can normalize to a few curves - but the default is NOT flat.

That sounds correct to me.  I currently use stereo mode with all processing disabled if I want the sub engaged.  Otherwise, I use direct mode which disables all processing and bass management (i.e., the crossover).  It's a quick and easy way to hear my SongTowers running full range without the sub.  Hit the stereo button and the sub comes back to life with the crossover engaged. 

Sounds like defeating the Audyssey settings for the L,R only isn't an option on this AVR (despite the type of curve that it applies).  No big deal, for me.  I'm pretty set on dedicated EQ for the sub.

[Gzerro]

Gzerro,

Thanks for the tip--I was wondering about that exact issue.  I was thinking that I could try out Audyssey for the sub only, but wasn't sure if/how that was possible.  Unfortunately, I have a lower line Denon AVR (3312) and it has XT, but not XT32.  I'll double check to see if there is a way to disable Audyssey settings for my mains.  In the end, the BFD is a reasonably priced EQ option, so that is what I'll plan to do for the long term solution.

The 3312 does have the option to apply bypass Audyssey to the left and right mains - see advanced audyssey settings of your manual. Your graph is looking pretty good with the new placement. I think you might be surprised at the improvement.

That said, in the long run I can understand why you would want a stand alone solution, especially if you are considering an upgrade your front end electronics. It will open up alot of options for you.

Good luck!

Tom

[Nuance]

Wow - that is a much better in-room response curve!  That will be easy to work with.  As you mentioned, add in the speakers and measure again up to 200Hz and then you'll know where you add the EQ filters in REW.  Speaking of which, I always manually add filters, as REW recommends way too many.  The less filters the better.  Based on your above response you should be able to get away with 3-5.  You should be able to play with your current measurement in REW and manually add filters to follow the 24dB poctave response curve.  Obviously you don't want to follow that curve when you add the speakers in, though, as it is meant to be EQd to only for the subwoofer running on its own.  With the speakers added in it'll ideally be a nice straight line or a slight downward curve as you move higher in frequency. 

[neekomax]

Hey, you might look into the Dspeaker Anti-mode Dual Core. I'm picking up a used one this week! 

Here's the big AC thread, in case you missed it: http://www.audiocircle.com/index.php?topic=110377.0

[chargedmr2]

The 3312 does have the option to apply bypass Audyssey to the left and right mains - see advanced audyssey settings of your manual. Your graph is looking pretty good with the new placement. I think you might be surprised at the improvement.

That said, in the long run I can understand why you would want a stand alone solution, especially if you are considering an upgrade your front end electronics. It will open up alot of options for you.

Good luck!

Tom

Tom,

Thanks for this info--I haven't messed with Audyssey much, but I will check this out at least in the interim.

[chargedmr2]

Wow - that is a much better in-room response curve!  That will be easy to work with.  As you mentioned, add in the speakers and measure again up to 200Hz and then you'll know where you add the EQ filters in REW.  Speaking of which, I always manually add filters, as REW recommends way too many.  The less filters the better.  Based on your above response you should be able to get away with 3-5.  You should be able to play with your current measurement in REW and manually add filters to follow the 24dB poctave response curve.  Obviously you don't want to follow that curve when you add the speakers in, though, as it is meant to be EQd to only for the subwoofer running on its own.  With the speakers added in it'll ideally be a nice straight line or a slight downward curve as you move higher in frequency.

I definitely breathed a sigh of relief after measuring in the new location.  It was a lot of work moving that sub around and given my limited flexibility, I was pretty worried that I would be stuck with some horrible nulls in the frequency response.  I'll do some more measuring this coming weekend and I'll post back for advice.

Thanks

[chargedmr2]

Hey, you might look into the Dspeaker Anti-mode Dual Core. I'm picking up a used one this week! 

Here's the big AC thread, in case you missed it: http://www.audiocircle.com/index.php?topic=110377.0

Thanks for the link--I've not seen this product, so I'll take a look when I get a chance.

[chargedmr2]

Wow - that is a much better in-room response curve!  That will be easy to work with.  As you mentioned, add in the speakers and measure again up to 200Hz and then you'll know where you add the EQ filters in REW.  Speaking of which, I always manually add filters, as REW recommends way too many.  The less filters the better.  Based on your above response you should be able to get away with 3-5.  You should be able to play with your current measurement in REW and manually add filters to follow the 24dB poctave response curve.  Obviously you don't want to follow that curve when you add the speakers in, though, as it is meant to be EQd to only for the subwoofer running on its own.  With the speakers added in it'll ideally be a nice straight line or a slight downward curve as you move higher in frequency.

Nuance & TJHUB -

I finally got around to measuring my sub in its new location along with both of the mains.  As you can see there is a pretty notable dip around 110Hz and just before 200Hz there is a huge dip.  Are these dips less serious from practical listening standpoint than, say, a large dip around 30Hz (like I used to have in my first sub location)??

Nuance, I didn't quite get what you were saying the first time I read your comments here, but I now see that I can use REW to predict my frequency response should certain filters be applied.  I still don't know how to do that, but I will do some more learning soon.

[Nuance]

^ Send me your mdat file (your REW file) and I'll work it to show you the predicted response.  I can also tell you the exact filters I used so that when you do get your EQ you can just enter them in, remeasure and see what you think. 

The dip between 100 & 200Hz seems to be present in most measurements I've seen.  Perhaps it is the floor/ceiling bounce that occurs?  My measurements show the same thing, but like yours the dip is narrow so I wouldn't worry too much about it.

PM me and I'll give you my E-mail if you do want to send the mdat file.

[chargedmr2]

Thanks Nuance.  I'll be home shortly and will forward the file along tonight.  I appreciate your willingness to help out

[Nuance]

Thanks for sending the file.  This is a general idea of what you can achieve with REW and your EQ...

The top line is the original, the bottom is the predicted response:


This is a snapshot of the EQ filters I applied:


And this is the predicted response again but also includes the predicted waterfall plot (it's hard to see the predicted vs. the actual because the graph used the same color):


You'll notice once the EQ has been applied the bass response is a bit quiter than the response above the crossover.  All this means is that once you're finished applying the EQ and achieving the frequency response you desire you'll have to use the subwoofer output in the receiver (or the subwoofer gain on the sub itself) and turn it up a bit.  Some people like the bass just as flat as the rest of the FR, but some prefer it a little hot; I fall into the latter camp, with my bass being 3-4dB hot for movies and music (below the crossover).

[TJHUB]

If I may, I would suggest possibly leaving that response alone.  The only thing I might consider doing to taking a few db off the 63Hz hump if and only if I heard an issue.  If I did EQ the 63Hz area, I'd also add a wide 20hz filter to boost 20Hz for movies. 

A lot of us with the TC Sounds drivers tend to run them a little hotter because they are so amazingly transparent.  If you find yours is not ultra defined and transparent, you need to feed it a better signal. 

[Nuance]

At the very least I would pull down the peaks at 37 and 63Hz.  You need to be careful boosting down low, even if it isn't a null, but if your amplifier is powerful enough you should be fine.  Just use caution. 

Here is what it would look like with just 2 filters to pull down those peaks, and then one wide bandwidth filter to boost at 20hz (+7dB and 12 bandwidth):


You can obviously tweak to your hearts desire, but this gives you a rough idea of what you can achieve.  The cool thing is use can use a variety of different methods in order to get where you want to be.