# Is something amiss in my setup?



## Digital_Chris (Apr 7, 2011)

Hey guys, sorry to bother.

According to REW and my ears, I've been having trouble with my LF response. To start fresh, I decided to take a few nearfield graphs of my subwoofers. According to many others, the graphs don't look right despite taking measurements the correct way, as placement of the mic near the subwoofer goes.

Here are my graphs...










The four different lines represent different crossover settings used just for comparison (40hz, 60hz, 80hz, and 100hz)

I was told the graph should be a lot smoother than what I have come up with.

I am using MAC OSX, Art Dual Pre sound card and Behringer ECM-8000 Mic.

I am connected from sound car to mac via USB, I am using the right channel on the sound card for readings, the left channel is looped via 1/4" to XLR cable. I am running XLR from sound card to mic, and from sound card to AVR input via 1/4" to RCA cable.

I have the loopback timing ticked in the REW menu and everything else seems ok. The sound card seems a bit wacky to me, needing to run the volumes at almost max to get the correct readings when I "check levels" and so on but I think I'm using it correctly otherwise.

If you could please ask as many questions as needed to get more info from me to help me solve this issue, it would be so helpful!

Again, sorry for another "how to setup REW". I have read the tutorials online and on youtube and like I said, everything seems ok but I'm just making sure with you guys because my graphs don't seem right, therefor, process of elimination has to take place :scratch:

Thanks!


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## acoustat6 (Mar 7, 2008)

Hi Chris, your results look correct, though not perfect. 
Whats your target/goal?

Bob
PHP143


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## JohnM (Apr 11, 2006)

The smoothness will be mainly affected by how far away the nearest walls are. Try moving the sub into the middle of the room and laying the mic on the floor in front of it.


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## Digital_Chris (Apr 7, 2011)

acoustat6 said:


> Hi Chris, your results look correct, though not perfect.
> Whats your target/goal?
> 
> Bob
> PHP143


Apparently a much smoother graph than this, I was told by a few guys on the other forum but what John says below, nothing may be wrong...



JohnM said:


> The smoothness will be mainly affected by how far away the nearest walls are. Try moving the sub into the middle of the room and laying the mic on the floor in front of it.


Thanks John, unfortunately, I can't move the sub(s) into the middle of the room as they are IB subs mounted right to the wall, the guys on the other forum know this too and still think something is very wrong with my graphs. You're thinking that they are so rough because they are right up against a wall and most likely my gear is not at fault?

That would make sense.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Digital_Chris said:


> If you could please ask as many questions as needed to get more info from me to help me solve this issue, it would be so helpful!


I’m uncertain what issue you’re asking help for: Your frequency response, your REW hardware, or your measuring process?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

The issue about my graphs not looking right for being nearfield measurements. Now I should probably be more specific when I say nearfield, these were taken with the microphone roughly 1 inch from the dust cap. I was told, that by having the microphone that close to the woofer, the room should not have much of an effect on my measurements.

If that's the case, then my graphs look odd for another reason which I would like to figure out. Is it my equipment? Is it the set up of my equipment? I'm not sure. The main guru of the infinite baffle forums recommended I go back to the beginning, and make sure my measurement software/hardware is hooked up and running properly, So I now turn to you guys.


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## Wayne A. Pflughaupt (Apr 13, 2006)

What is a nearfield measurement supposed to look like? 

And why even do nearfield? A listening-position measurement will get you a representation of what you’re actually going to be hearing from your sub. A nearfield measurement won’t. Unless you have some specific purpose?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

I guess it should look a lot smoother, something like this...










I'm doing nearfield measurements due to the recommendation by a few other tuning guru's. It's a good starting point to know that my gear is performing the way it should, minus the room. If I know that everything is solid from the get go, I can then try to fix problems caused by my room, and not the software / hardware.

I've been taking "at the seat" measurements for some time now battling response curves due to my small room and heavy LF room modes. I also have trouble above my crossover region, the graphs are pretty wacky. I figured I'd start "fresh" and make sure my gear is up to par first.


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## acoustat6 (Mar 7, 2008)

Hi Chris, I allready said they look fine, need more concensus?:bigsmile:
Really the question is how do they sound?:hsd:

Bob


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## Digital_Chris (Apr 7, 2011)

To be completely honest bob, there is none of this :hsd: happening.

When my graphs for the front row were showing a fairly "flat" response, there was no bass felt from said row. The rear row shows a huge 30hz mountain in my graph and that row is very boomy, too boomy actually, but again, no bass felt in the front row which is pretty flat.

Bottom line is I've been unhappy with all of my results so far and having such a hard time grasping why everyone else that has an IB setup or any decent LF setup for that matter, are extremely pleased with their house shaking results.. I don't understand!

Sometimes I feel that something *must* out of wack but as far as I can tell, their isn't. I really really don't understand how people feel the low bass that I seem to lack.

Some people seem to be able to throw together an IB setup or just buy a bigger sub for their living room, apply no EQ or measurements with REW and get superb results! It makes me do this :unbelievable: and then this :hissyfit: and then makes me go like this :dontknow: and then this :crying: because I can't take it anymore!

:rofl:

Anyway, you don't know how bad I wish someone could come over and help me figure this out, I had no idea this whole thing would be so hard, and I'm only currently working on the LF issues when I still have reflections to tame! :dumbcrazy:


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hey Chris,

Can you give us a description of your IB system and equipment and some details about your room, or even better, pictures?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

I'll provide you with a few details.

Room dimensions are 18' x 10.5' x 7'

6 theater seats, two rows, 3 seats per row.

First seat is 9' from screen / subwoofers and rear seat about 14' from screen / subwoofers.

(4) FiCar audio 18" IB subwoofers in a line array on the front wall powered at 4ohms by a Behringer EP4000 amp. Marantz SR5005 AVR and I also have a Behringer Feedback Destroyer inline but not hooked up at the moment.

I have a 60hz mountain in my graphs at the front row and a 30hz mountain followed by a grand canyon dip in my graphs at the rear row, both probably due to the length room modes. Even if I could move the seats, I would not be able to get out of the peaks, they are that wide.

No amount of absorption that I am willing to put in the room will take care of those mountains and valleys. I'm willing to try a tuned panel absorber(s) next so I can stay away from super amounts of fluffy fiberglass.

With all of that aside, even if I tame the 60hz peak in the front row via the BFD, I actually can get a nice flat graph but when I do, there is almost no bass felt at that row, especially in the really low end of the spectrum where these IB's are supposed to shine. This is all after I level match the speakers as well.

So, with the peaks an valleys that I'm fighting ontop of why I don't feel much bass anyway, this part of the build is just killing me.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> dimensions are 18' x 10.5' x 7'
> 
> 6 theater seats, two rows, 3 seats per row.
> 
> ...


Assuming your 18’ dimension is the room length, the reason for the front-row dead spot is easy to explain: In any square or rectangular room there is a bass “dead zone” in the center of the room, and that’s exactly where your front row seats are. It’s easy to “see” with a SLM: Play a low frequency pink noise signal and you’ll notice the meter’s dB reading increases as you move from the center of the room towards any boundary.

Where on the front wall is the IB located?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

That row certainly *feels* like a dead spot but it feels the same even when I get the graph pretty flat for that row...

Here is a graph I just took, the two center IB's only, the side two were removed and the holes plugged. I temporarily moved the x-over up to 100hz and unplugged the LCR speakers. Blue is front row and red is back row...










Here is a shot of the front of the room so you can see the speaker layout...


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## Wayne A. Pflughaupt (Apr 13, 2006)

I’m personally not fond of center-wall placement for subs. The one time I tried it, response was absolutely abysmal compared corner placement. Do you have any measurements of just the outer two subs?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

Not yet Wayne, the inner two were a recommended starting point by the main IB guru. I have no problem swapping them to the outer sides and run a few sweeps for comparison 

How do my graphs look for no room treatment besides carpet, theater seats and front wall absorption? I think they look pretty terrible... :sad:


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## Digital_Chris (Apr 7, 2011)

Here is a graph of the outer two IB's...










Not much of a difference.


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## Digital_Chris (Apr 7, 2011)

And just for comparison, all 4 IB's, same settings...










Pretty much same graph, just higher db.


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## Wayne A. Pflughaupt (Apr 13, 2006)

What strikes me as unusual is that there’s virtually no difference between the measurements for the inner and outer subs. So something does seem amiss, but I’m at a loss as to what it is. Any way you can get a decent ”regular” sub in there for some comparison measurements? 

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

Sure, here is a graph of two MFW's. I ran two sweeps, one with the subs in the center of the wall and the other with them at the outskirts of the wall just like the IB's. They are almost identical up to the xover point...










And just for haha's, here is a graph of the MFWs I just took after moving one sub to the center of the front wall and placing the other at the center of the rear wall... Goodbye 30hz eh?


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## Wayne A. Pflughaupt (Apr 13, 2006)

That red trace in the last graph isn’t bad at all. You might just have to add those MFW subs at the rear of the room to balance things out.

But going back to the basics, what are you using for a measurement mic, and calibration file for it? And I assume you have a calibration file for your sound card?

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

I did try the MFW's in the back and they helped out big time but I was afraid that they would run out of juice way before the IB's did so I turned that idea down. I then tried using two of my IB's in the back corner with two still up front and that suprisingly didn't help much at all, so I may be back to just the MFW's only, and ditch the IB's :crying:

I'm using the Behringer ECM-8000 mic with a forum users cal file that was a bit better suited to my mic than the generic ECM-8000 cal file on here. (I sent my mic to him and he tested it out with a few cal files he had). 

I used the cal file that I made when I bought the sound card


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## Wayne A. Pflughaupt (Apr 13, 2006)

Digital_Chris said:


> I did try the MFW's in the back and they helped out big time but I was afraid that they would run out of juice way before the IB's did so I turned that idea down.


Have you used the MFW’s before? If you did and you didn’t have a problem with them “running out of juice,” then I’d go ahead and use them along with the IB. It doesn’t matter if they “give up” before the IB if they’re able to “hold up” to your most demanding listening.

Regards, 
Wayne


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## AudiocRaver (Jun 6, 2012)

Just catching up on your thread, thought I'd throw out a couple of thoughts for what they are worth.

My two cents worth on your initial question, nothing appears wrong with your measurement methods. Measuring close to the cone at low frequencies doesn't help as much in your situation because the proximity of walls, floor, etc. are affecting your IB characteristics and the movement of the speaker itself. It is the right idea, as you suggested, for getting a close-up of how the speaker is acting minus the room (somewhat), just not quite as helpful in your current situation.

The 30 Hertz resonance is the fundamental frequency for the IB driving the length of your room, speakers at one end versus wall at the other. Placing another sub at the back wall "cancels out" the back wall so to speak, and there goes the 30 Hertz peak.

The 60 Hz peak looks like it's the fundamental standing wave frequency for the length of the room.

Running a sub or two at the back of the room could help tame the 30 Hz, even running them at a lower level so they don't run out of gas would help some. The 60 Hz peak might need a resonant trap. Or equalization. Or some of both.

Best of luck. Looks like it will be a nice room.:sn:


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## AudiocRaver (Jun 6, 2012)

Another thought just popped into my tiny brain. Only room for one at a time in there sometimes. Especially on lazy weekends.

Could some of that infinite baffle space in your front wall be turned into 60 Hz resonant bass trap? That would be a good place for it,


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## Wayne A. Pflughaupt (Apr 13, 2006)

Dumb question maybe, but you are taking measurements with the doors closed, right? Just trying to cover all the bases...

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

Hey Wayne,

I have not used the MFW's with the IB's other than testing, I may have played a bit of a movie but nothing major, the MFW's were working pretty hard while the IB's were barely moving so I figured I'd cancel out that idea. Plus, I would still have to buy another amp for the MFW's so I don't have to run all 4 IB's on one channel of my EP4000 amp, the two ohm load isn't recommended. The other guys were talking about phase/delay for the rear subs an it was pretty overwhelming as is.

To your other question, I have run all tests with the door closed, thanks for asking 

Raver,

You're saying that the 30hz and 60hz peaks are both fundamentals frequencies of the length of the room, correct? I *was* able to cancel out the 30hz peak in the rear row by having one MFW center front wall and one center rear wall. Unfortunately, I could not get the same effect from having two IB's up front and two IB's in the rear corner, it seems like sub placement in the back of the room is key? The 60hz stayed the same whether it was MFW's or IB's.

I don't really understand your question about uising some of my front wall as a resonant trap.

Why is this tuning process so ' difficult?!?! I just want my room to sound good. I didn't think I would have this much trouble with the bass. Everyone else makes it sound so easy! Haha..


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## acoustat6 (Mar 7, 2008)

Hi Chris, you mentioned a build thread and IB gurus, would you mind a couple of links to your build or other info and which site. the IB should rock your world!


Bob
PHP143


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## Digital_Chris (Apr 7, 2011)

acoustat6 said:


> Hi Chris, the IB should rock your world!
> 
> 
> Bob
> PHP143


Haha, yeah, everyone keeps saying that. No, seriously, it doesn't even vibrate my seats, never mind rock my world... :dontknow:

Here is my build thread over on AVS and here is a the thread of mine on the "Cult Of The Infinitely Baffled" forum.


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## acoustat6 (Mar 7, 2008)

hi Chris, looked quickly thru the threads, very impressed with the amount of work you did:T:clap:!

Dont worry you will get this figured out, though I understand your frustration.

Bob
PHP143


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## FOH (Aug 27, 2012)

Digital_Chris said:


> Haha, yeah, everyone keeps saying that. No, seriously, it doesn't even vibrate my seats, never mind rock my world... :dontknow:
> 
> Here is my build thread over on AVS and here is a the thread of mine on the "Cult Of The Infinitely Baffled" forum.


Hello gentlemen,

I've followed this from the begining. A few notes;

The measurements have wildly varying swings, thus the concern.

Before energy and frustration is wasted chasing issues, reasonable confirmation of the measurement system accuracy is needed. The quick method to determine there's no wild inaccuracies is the nearfield sub measurement. Plus, it's quite useful to check to assure all is well with the build, signal path/amp rolloff,..etc. Basic first step to save mucho grief. Even a cheap RatShack meter used w/REW would confirm whether or not these graphs/your gear and methodoloy is ok. 

Those close mic graphs are suspect. It's either your system, or your measuring gear/cal etc. 

A nearfield close mic cone measurment, diminishes the relative significance of the "room", since the signal of the cone is greatly higher than that of the room's acoustic distortions that arrive a short time later. A typical sub close mic measurement is closer in appearance to a nice arc, not unlike outdoor groundplane measurments, than the weird graphs posted. 

The graphs Chris have posted illustrate the effect of the rear wall, and it's interaction with the direct energy at the LP, and the room's modal behaivior. Nulls are from destructive reflections, nothing else. 

Either a massive entire rear wall bass trap, or the addition of rear subwoofer(s), will address these big swings in FR, both lessening the peaks and the dips. 

This is critical, and hasn't happened yet;
The rear subs must have adjustable time/phase alignment, relative to the front output, to fully realize their benefit. To achieve this, they must have their own amp channel and means to adjust the alignment. There's many ways to make that happen, one being an inexpensive Behringer I-Nuke DSP amp, $299. 

Chris, I've politely tried to help accross multiple forums, offering this advice along the way. There's no magic bullet here, but this is solvable with those steps....and AFAIK, they've yet to be fully taken.


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## AudiocRaver (Jun 6, 2012)

Digital_Chris said:


> I don't really understand your question about uising some of my front wall as a resonant trap.


I am probably not picturing your design properly. From your photo, I assumed the front wall to be built out some distance with space behind it for your front speakers and IB. If so, some of that space could be turned into base trap, requiring major mod to the design, loss of some of the IB volume. It would mainly affect the 60 Hz peak. That might not be what you have there at all, if not, ignore the silly suggestion.

FOH's post had some good advice, sounds like he's been through a lot of the same issues. Especially the rear subs and the need for phase/time adjustment for them. The rear wall bass trap idea would be a better option than front wall because it could help with both the 60 Hz and 30 Hz peaks if properly designed, don't know how much space you have back there for it, though. That was my only reason for bringing up a front bass trap, the possibility of space for it there.



> Why is this tuning process so ' difficult?!?! I just want my room to sound good. I didn't think I would have this much trouble with the bass. Everyone else makes it sound so easy! Haha..


Sounds a little frustrating. Again, FOH's advice is good, when you are stuck or frustrated, it is smart to take a deep breath, step back, start from the beginning, step through it all again, especially _question all your assumptions, including your expectations._ Have you head anyone review your IB design? You might post it in one of our sub design forums.


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## EarlK (Jan 1, 2010)

*Just spit-balling here , but ;*










This is the type of pic that I would expect to see from a "Dipole" bass setup ( before it's been EQed ) .

The notch ( at 34hz ) can be explained by flexing ( cancellation ) of the baffle-board ( wall ) .

I think your IB is acting more as an OB ( than IB ) . If so, your search for solutions will need to follow the path of "How to Successfully implement Dipole OB Bass" .

*IB Criteria ( for Successful Implementation ) ;*

Is there an itemized list ( with thresh-holds to meet ) that will help predict IB success ? Got a link ?

:sn:


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## Digital_Chris (Apr 7, 2011)

FOH,

I sincerely apologize if it seems like I'm ignoring your advice, as I am not, but when I get advice from you that says one thing and then on the same topic, another user says something different, it's hard to proceed with say, your advice when it may or may not work in my situation, such as implementing a $300 amplifier to add in phase/timing control hoping it will help, if not, I'm stuck with a $300 amp :-/

Please see this thread. Take a look at the 2nd to last "quote and reply" from Thomas in his most recent post and you will see what I mean.

He also mentions this...

"You have a Element Designs eq.2. It will adjust phase (at a single frequency). To measure phase differences between speakers requires use of an oscilloscope. Do you have an oscilloscope?"

That doesn't sound right to me. I thought that the "phase control" would control the phase only, 0 deg to 180 deg, 180 deg meaning firing completely oposite of the other drivers, correct? Not frequency dependent, and how do I even set said frequency for phase adjustment?

:scratch:


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## Digital_Chris (Apr 7, 2011)

EarlK,

I'm not following to well as far as the OB dipole setup...

I've read all the FAQ's on the IB forum and such, the complete build didn't seem like a very complicated task.


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## FOH (Aug 27, 2012)

Digital_Chris said:


> FOH,
> 
> I sincerely apologize if it seems like I'm ignoring your advice, as I am not, but when I get advice from you that says one thing and then on the same topic, another user says something different, it's hard to proceed with say, your advice when it may or may not work in my situation, such as implementing a $300 amplifier to add in phase/timing control hoping it will help, if not, I'm stuck with a $300 amp :-/
> 
> ...


No appolgy needed. 

First an foremost, you have got to establish some type of verificaton of whether or not your measuring setup can be trusted. If you use a Radio Shack meter, with whatever cal file, and achieve similiar results, then your graphs can be trusted. 

The phase control in the eq2 (I own one), will enable you to mate the entire sub system to the mains. Or, one sub group to another. Yes, it works as he stated, not as you thought. You're descrbing polarity reversal, entirely different. 

The only way to get by without seperate time/signal alignment of the rear subs, is if they were exactly equidistant from the LP as the front subs. As little as 3.5 foot differance between the two subs can create cancelation at the upper range of the sub. 

With the time alignment capability, first you align the two groups to sum fully, and examine the subsquent response. If needed, you will make small changes in time delay while examining the response peaks and nulls. By manipulating this alignment, significant smoothing of the freq response can occur. In acoustics, the time domain controls the freq domain. It's all about the time domain, and the complex manner in which reflected energy interacts within the room. 

In my best guess, when others didn't agree that you should buy more gear, I'm thinkin that was likely due to them not being confident your ablity to use it until this measuring system/gear issue was resolved.

Now, recently there is new gear to hit the market. Both from Parts Express and miniDSP. These are measuring mics that don't need any additional equipt. They plug directly into your computer via USB. These are in the $70-$90 range, work with REW etc, and really simplify the entire process for many. If you had acces to a RatShack meter, or equivalent, great. Otherwise, perhaps these could help.


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## EarlK (Jan 1, 2010)

Chris,

- Why not simply ask your advisers over at the IB forum what other forms of measurement would they accept that would quell their doubts ( about your measurement techniques ) ? 

- After-all, you have other speakers that you can use to display your measurement techniques .

- For instance, how about near-field ( & far-field ) measurements of those MFW subs, in various locations of your basement outside of your HT, ( as well as upstairs ) ?

- What about nearfield miking the cones of the those 3 Ewave speakers ?

- A ( "he said, she said" ) debate like this, is ultimately counter-productive . 

:sn:


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## FOH (Aug 27, 2012)

EarlK said:


> A ( "he said, she said" ) debate like this, is ultimately counter-productive .
> 
> :sn:


Earl,

Given the entire scope of these public exchanges (I'm confident nobody has followed them much more closely than myself), I wouldn't characterize this in that manner at all. 

All the best


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## AudiocRaver (Jun 6, 2012)

Chris,

You are getting lots of great advice, some of it being delivered with enough passion that it may be coming across sounding a little argumentative, but in reality most of the substantive comments are in agreement: step back, get a good baseline before moving forward. In my personal opinion, the best advice recently given was to take one of your MFWs or some full range speaker to another room or even outside, if possible, and get a good, sane-looking measurement from SOMETHING to give you confidence that your measurement setup is working right. "Working right" meaning equipment functioning properly, configured properly, and all being used properly. I would do this before spending another penny on equipment. Except maybe the microphone. You are looking at 20 dB swings, a properly functioning full-range uncalibrated microphone like the Behringer might account for a few decibels of error, no more, so it is not critical at the moment, but you will absolutely need it for EQ fine tuning soon enough. It is remotely possible you have a defective microphone, and if you don't get a sane looking measurement with your sub out of doors, that is something to look at.

Back in post number eight, you presented a very sane looking curve, saying,, "I guess it should look a lot smoother, something like this..." How did you get that curve?

One other question, you are using the line output from your ART audio interface, correct? The headphone output with the mix knob in the mid-position under the right circumstances could give you two signals mixed together with enough relative delay to possibly cause some serious weirdness in measurement results. Beg pardon if this is already overly obvious to you, it just occurred to me as a possibility so I thought I would throw it out there.

Once you have the sane/normal looking plot that you can post, demonstrating confidence in your measurement equipment and its use, you should be able to make good progress with all the expert advice. How fortunate, being able to go online and have so many experts willing to pitch in to help make your room sound great.

Appreciation to all who are helping, and much appreciation for keeping this spirited discussion in the respectful/friendly zone!:bigsmile:

AudiocRaver


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## acoustat6 (Mar 7, 2008)

Hello Chris, any progress with your set up? I am sure with the holidays you have been busy, but I have not seen any progress on your posts.:wave:

Bob


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## Digital_Chris (Apr 7, 2011)

Hey guys, sorry I've been distant recently, thank you for your responses 

I have taken some time away from downstairs because I don't need that frustrating me during the holidays. I am ready to work on it some more though 

I was going to go downstairs tonight and take some more measurements but I just don't have the enthusiasm to do so right now, in stead, I am posting a few pictures of my sound card and cabling so you can verify that I am using the correct stuff.

Here is my sound card...




























I go from microphone to "right input" with this cable...










Then I loop "left input" to "left output" via this cable...










Then I go from the "right output" on the sound card to the receiver input via this concoction...










Does this all seem ok so far?


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## Digital_Chris (Apr 7, 2011)

Raver,

That smoother graph I posted was from another member on the other forum showing me _his_ nearfield graphs and what mine should resemble.

EarlK,

Within the next day or two, hopefully I will have the motivation to take a few more measurements, when I do, I I will take a measurement of one MFW in a more open space, followed by a measurement of each ewave speaker, we'll take it from there


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## AudiocRaver (Jun 6, 2012)

Just a follow-up, wondering how your project is coming. Ever get those measurement questions settled?


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## AudiocRaver (Jun 6, 2012)

There is nothing obvious wrong with the way you are using your measurement equipment.

Where we left off, you were going to take some kind of measurement outside of your theater room, to see that your measurement setup is working properly. Hopefully that is not too much trouble. Good luck.


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## Digital_Chris (Apr 7, 2011)

Hey Raver,

Here is a graph I just took with one MFW by itself, no other speakers/subs playing, in the "center-ish" of the room. I think this looks pretty good, no? I mean, it is a bit squiggly above my x-over point, but other than that, better than the IB's.


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## AudiocRaver (Jun 6, 2012)

Not knowing any specifics about that unit, it looks very respectable to me. That should satisfy any questions about your measurement setup and operation.

It seems like your next step is to somehow simplify your IB measurement approach to the point where you get plots that makes sense, then work up from there. For instance, what if you were to take the unit you just measured and place it right beside one of your IB drivers, right against the baffle (pointing into the room), then run plots of each of them separately, up close and at different points in the room? You should expect somewhat similar plots at each measurement point for the two sources, your IB and the MFW. If you get that, then you know the room is to blame for any strangeness. If you don't get that, you know the IB is doing something strange. At least I think you should be able to expect that. You had a number of other experts helping before, their advice for how to proceed is welcome at this point.

Keep track of exactly what you did to get the plot above. It can be very helpful to have a reference point you can return to if you run into trouble getting meaningful results later. Onward and upward!


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## Digital_Chris (Apr 7, 2011)

Thanks for keeping an eye on my progress, I will try to get some more comparisons soon, maybe tonight if I get motivated down there.


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