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Discussion Starter #1
Greetings,

I have a pair of bookshelves with 5.25 drivers and a 12" powered subwoofer that I am trying to integrate correctly. The purpose of this exercise is to ensure that I have my sytem calibrated and integrated properly to its fullest potential so that I can make a better decision as to whether an upgrade in speakers is actually necessary. It may just be that if I integrate my curent system accurately and it satisfies my tastes then I may have no need to upgrade, ever!



Steps I have completed:

1. Set sub to default volume level

2. Determined optimal placement by using the poplular "Crawling for Bass Technique"
http://www.audioholics.com/tweaks/sp...ofer-placement

3. Set my intial speaker levels with Avia test tones and Radio Shack SPK


Now I have come to a crucial crossroad that I fell will either make or break my Sattelite/Sub integration (I think it's OK to call Bookshelves with 5" woofers a sattelite speaker?). Keep in mind I am bypassing the Subs onboard crossover by setting it to direct mode.


I have done some reasearch and have come up with two theories that make the most sense to me. Keep in mind that the most popular theory is set it to 80HZ and forget it. I threw that one out the door because it is just a generatlization and doesn't take into account any unique factors that make up my system. In other words it is not scientifical enough for me.


So here are two theories that seem to make some sense scientifically.

1. Set the Crossover a the -3DB rating of the bookshelf which would be 75HZ

2. The bass of the main speakers must be flat to one full octave below the subwoofer crossover point. However this is not mentioned in articles as frequently as step 1. ( http://www.soundstage.com/maxdb/maxdb021999.htm )


1. Setting the crossover with the -3DB theory I went with 80HZ on my receiver, which is what I have been using since I've had the setup (4 months or so). I was never really happy with this crossover setting. Music did not reveal great uniformity. It appeared as if there was some gap between the sub and the sattelites and upper frequencies 200HZ + did not sound organized, a bit muddy when I turned up the volume. For a test I used Avias low pass sweep test in it reavealed dips and gains of +- 10DB on the SPL throughout the range and extreme dips at 180HZ, 120HZ and 60HZ.

2. Setting the crossover 1 full octave above the -3db mark of 75HZ of the bookshelf (150HZ) appeared to yield better results. Material appeared more organized, sounded much cleaner at higher volumes and appeared to integrate better with the subwoofer (I did not appear to get much localization as most people would suggest). The SPL meter and low frequency slope showed that the dips and gains weren't as severe throughout the 20-200HZ frequency band but it did still reveal some, but not as many, dips of +/- 10 DB. I would think that the cleaner sound in the 200hz + range would be due to the lightened load placed on the AVR. This has confused me because according to my subwoofer manual ( http://www.velodyne.com/products/man...nglish_web.pdf ) the subs 12" sub starts its roll off around 120 HZ +/-3db. And from everything I have read frequencies above 80 HZ on the subwoofer can be localized. However, we just can't go by the cutoff because crossover frequencies is a game of slopes and unfortunately I don't know the crossover slope of the AVR (onkyo HTR 550) . But I do know the passive subwoofer on the Subwoofer is a +/- 6 DB. Not sure if this comes into play if the crossover on the sub is defeated or if it just means that the frequency will roll off above 120hz at a rate of -6DB per octave? Can anyone help explain this better?


Ultimately I am left confused on using the crossover for better system integration. Although it appears the 150HZ setting has tightened up my system it goes against 90% of the things I am hearing. Most sources state the crossover should be between 100-80HZ, including the instruction manual for my speaker. This leads me to some closing thoughts:

1. 80 HZ may be correct but I don't know how to setup my subwoofer or my subwoofer is a piece of junk. But that wouldn't support the increased clarity I get from the bookshelves by setting the crossover higher. If 80HZ was the correct setting than it should sound just as good if not better on my bookshelves when compared to the 150HZ setting.

2. Acoustical conditions in my room and slopes between my equipment may not be good for a 80HZ crossover setting

3. 150 HZ or 1 octave above the -3db point is the correct crossover frequency for these speakers.


If it is #3 then I clearly think I am left with some issues I can do nothing about:

If the 120HZ is the +/- 3DB rating on the high end of my subwoofer then that would mean, using the 1 octave rule that the subwoofer is only flat up to 60 HZ. If this is the case then since my bookshelves are flat down to 150HZ and the sub up to 60HZ then I have some uncertainty going on between 60 and 150HZ in my system and this is where my SPL and low frequency sweep test pattern show the most movement.


In the end does it go against all common logic to set a crossover frequency of 150 HZ for a bookshelf with a rating of 75hz @ +/-3db and a 12" woofer with a high pass of 120 @+/- 3db?


Thanks for listening.
 

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Quote:
2. The bass of the main speakers must be flat to one full octave below the subwoofer crossover point.

Although this is probably a good "rule", theoretically, it is not set in stone. Many will and can present good arguments that any setting that is reasonably above the speakers' -3dB point should be sufficient. In your case, 80Hz may be a bit low considering your speakers' -3dB point is 75Hz. But 100Hz is probably a reasonable setting. If your speakers are flat to 100Hz there is really no reason this should not be OK.


The ability to measure your room's FR can be very useful as it allows you to see the actual behaviors provided by different xover settings. The general goal would be to set the crossover at the lowest setting possible that still provides a flat response with a caveat being that the sub may actually be able to better reproduce the lower frequencies that the speakers are also capable of (or not). There is a chance, depending upon the room's FR, that the xover setting could actually be lower than your speakers -3dB point. You don't know this until you measure your room's response.


One thing that you didn't mention (or maybe I missed it) is that another generally accepted (and broad) "rule" is that bass above 80Hz becomes increasingly localizable. If your sub is not centered (or at least somewhere) between and along the same wall as your front speakers, this localizability is undesirable. This is the reason behind the oft-used 80Hz setting.


So, again, in your case, even without the ability to accurately measure your room's FR, a 100Hz setting is probably more reasonable than 80Hz and should provide a balance between the need to use a higher xover setting and the need to minimize localizability.


Frankly, 150Hz is too high considering your speakers' -3dB point of 75Hz. I think that deviations from the "bass of the main speakers must be flat to one full octave below the subwoofer crossover point" "rule" are more reasonable and acceptable the higher a speakers' -3dB point. I suspect that many people who use the common 80Hz crossover setting (myself included) do not utilize speakers with a -3dB point as low as 40Hz.
 

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Also it should be noted that, at least in my experience and from reading a lot of reviews, very few speakers (especially bookshelves!) are actually -3dB at their "spec'd" -3dB point. If you try to set your crossover at the -3dB from the specs, you will usually end up with a "hole" in the mid-bass as you experienced. A good rule of thumb is to go at least 20Hz higher than the specified -3dB point, thus siv's recommendation of 100Hz or even 120Hz.


Of course, it must always be said that every room/speaker combination is unique and there is no substitute for actual measurements. You've got an SPL meter and test tones, play around with various settings and check which gives flattest reponse.
 

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Discussion Starter #4

Quote:
Originally Posted by sivadselim /forum/post/14268092


. But 100Hz is probably a reasonable setting. If your speakers are flat to 100Hz there is really no reason this should not be OK.


Ok. I will try to calibrate my system at 100HZ tonight.




Quote:
Originally Posted by sivadselim /forum/post/14268092


. One thing that you didn't mention (or maybe I missed it) is that another generally accepted (and broad) "rule" is that bass above 80Hz becomes increasingly localizable. If your sub is not centered (or at least somewhere) between and along the same wall as your front speakers, this localizability is undesirable. This is the reason behind the oft-used 80Hz setting.

I believe I mentioned, but becuase of the jumbled and reasonably long and confusing post it could have easily been missed. Here is a sketch of my setup. You will see the 12" velodyne is right next to the opening for the kitchen. I have played around with location on both sides of the TV stand but that corner on the other side just gets crazy boom. In it's current location I hardly get any localization even at 150Hz.






Lastly, if you wouldn't mind looking over this frequency graph it appears that it only remains flat down to about 150hz and it goes down from there to 75hz at -3DB:
http://www.aperionaudio.com/catalog/...x?versionid=36


And then this manual (Look at the specs for the 12" version) : http://www.velodyne.com/products/man...nglish_web.pdf


So basically we have a sub that hits the -3DB rule at 120HZ and a bookshelf that hits the -3DB rule at 75HZ. Would you still suggest the 100HZ crossover in this scenario?


One other important thing to note is that I have surrounds that hit the -3DB point at 120HZ.


The thing that got my attention was how much cleaner my bookshelves sounded with the 150HZ setting vs the lower settings.


thanks for taking the time to read that mess. I'm just wondering if I would have gotten better integration by going with a smaller 10" sub or if my setup is less than ideal.
 

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Got your PM.


Just looking at this, I think I'd go with a 120hz crossover.


Based on the published numbers, that's where your best intergration should be. Problem is that often times these numbers aren't corrrect.


The only way to really know is to run some frequency sweeps to see what's going on.


As for your gaps as 60, 120, 180hz, you've got some kind of null going on as they're all multiples of 60. You'll have to ignore those.


Try the 120 hz crossover and boost your sub to 5 dbs higher than your other speakers. See how that does.
 

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Quote:
Originally Posted by dlenart25 /forum/post/14268595


In it's current location I hardly get any localization even at 150Hz.

That seems believable for that particular location.


Quote:
Originally Posted by dlenart25 /forum/post/14268595


Lastly, if you wouldn't mind looking over this frequency graph it appears that it only remains flat down to about 150hz and it goes down from there to 75hz at -3DB.........

Yeah, but there is actually a little hump there ~150Hz.


Quote:
Originally Posted by dlenart25 /forum/post/14268595


So basically we have a sub that hits the -3DB rule at 120HZ and a bookshelf that hits the -3DB rule at 75HZ. Would you still suggest the 100HZ crossover in this scenario?

I think 100Hz is a reasonable setting in this case.


Quote:
Originally Posted by dlenart25 /forum/post/14268595


One other important thing to note is that I have surrounds that hit the -3DB point at 120Hz.

If you can't set different crossover settings for each speaker, then this is something to consider. Personally, I think a little hole in the surrounds' FR is preferable to a higher crossover setting, but that is just my opinion.


Quote:
Originally Posted by dlenart25 /forum/post/14268595


The thing that got my attention was how much cleaner my bookshelves sounded with the 150HZ setting vs the lower settings.

Yeah, that is also believable. Depending upon your sub and speakers' exact capabilities you will get different results with different xover settings. If the sub reproduces those higher bass frequencies better than the speakers can...... there you go. But many people feel their speakers' smaller drivers can reproduce those higher bass frequencies better. On the flipside, freeing the speakers from having to reproduce those lower frequencies may improve their midbass and midrange performance. I think this probably varies from setup to setup.


Your room and the speakers and sub may have a hump or humps in the FR that are actually tamed by the 150Hz crossover setting. As pointed out, you can do some crude measurements with your SPL meter to at least get a handle on what is going on. Just be aware that the room can really give you a wildly varying FR. But you can graph the results of several settings to see which gives the "best" FR. And you may not even prefer a flat FR!


In the end, you should do what sounds best to YOU. Arrive at a setting you prefer and enjoy your system. Although they are important, you can drive yourself crazy worrying about all the details, which takes all the fun out of simply enjoying your equipment. Also, it is very hard to instantaneously make judgments about particular settings without thoroughly listening to a lot of different material over a longer period of time. Set a setting and try it out for a few days. Then, if you wish, try another setting out for a few days.


Quote:
Originally Posted by dlenart25 /forum/post/14268595


I'm just wondering if I would have gotten better integration by going with a smaller 10" sub or if my setup is less than ideal.

Well, that seems sort of counterintuitive as you seem to be indicating that you are getting reasonable performance from the larger sub even with the 150Hz setting.
 

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Discussion Starter #7
So would it be reasonable to conclude this post by saying that there is no specific scientific forumula for calculating the best crossover setting based on graphs and numbers and theory becuase of multiple factors such as...


-Acoustical properties presented by the unique listening enironments

-How system component interact with each other (receivers, speakers, DVD Players)


Theory gives us an idea of how something may change by making an adjustment but it will not give us a garuntee in outcome. The garunteed outcome is acheived by starting at a reasonable starting point and continously tweeking untile the desired results are acheived.


One last question. Do you have any tips on using Avia's 200HZ-20HZ frequency sweep and SPL meter? What sort of things should I be looking for as the sweep goes through? What are some reasonable expectations of results in terms of the +/- DB flucutation on the SPL as the frequency sweeps. I've noticed that sometimes it fluctuates more than 10db at certain points?


Also, how does one go about taming these fluctuations? Moving equipment, playing with the onboard EQ of the AVR


Thanks again.
 

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Quote:
Originally Posted by dlenart25 /forum/post/14269282


So would it be reasonable to conclude this post by saying that there is no specific scientific forumula for calculating the best crossover setting based on graphs and numbers and theory becuase of multiple factors such as...


-Acoustical properties presented by the unique listening enironments

-How system component interact with each other (receivers, speakers, DVD Players)

Mostly the acoustic properties of the listening environment and the sub and speakers' performance (obviously, their individual published FRs) and acoustic interactions.


Quote:
Originally Posted by dlenart25 /forum/post/14269282


Do you have any tips on using Avia's 200HZ-20HZ frequency sweep and SPL meter?

That is, basically, impossible to do. What you need are individual tones at different frequencies. HERE is a link to some 1/6 octave sine wave tones that you can use. There are also some sweeps included. And there is a sample/example Excel spreadsheet that you can use to graph your measurements if you have Excel. The Excel spreadsheet will properly take into account the correction factors necessary for the Radio Shack SPL meter, if that is what you are using. Just delete the current values that are there, and insert your own measurements. Do not worry about the pre- and post-BFD measurements as these are measurements of that particular sub and room after the application of equalization utilizing a Behringer Feedback Destroyer. You can simply delete the post-BFD values so that that graph doesn't show up.


Provided your DVD/CD player can playback MP3s, just burn them to a disc in the proper order. If your player can't read MP3s, you will have to convert them to .wavs, first. Make a note of which tracks correspond to which frequencies so that you can navigate the disc you burn properly. The tones begin at a lower dB than they eventually arrive at so as to avoid any accidental damage to your speakers/sub. Set the receiver at a volume setting that gives you ~75dB (or 85dB) with one of the intermediate tones. Of course, the SPL will vary, sometimes dramatically, from tone to tone (that's the whole point!). So, experiment with a receiver volume setting that works best with most of the tones and leave it at that setting to do all the measurements. You can also do measurements of your speakers' and sub's individual responses at different crossover settings by unplugging or disconnecting one or the other. This will demonstrate some of the weird acoustic interactions that can occur.


Quote:
Originally Posted by dlenart25 /forum/post/14269282


Also, how does one go about taming these fluctuations? Moving equipment, playing with the onboard EQ of the AVR.

With an equalizer such as the BFD, by moving the sub around, and (importantly) room treatments. The subwoofer's phase and/or distance setting can affect this dramatically as well. If your receiver has onboard EQ and calibration, then you should definitely be using that, although its capabilities are somewhat limited.
 

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Discussion Starter #9

Quote:
Originally Posted by sivadselim /forum/post/14269478



That is, basically, impossible to do. What you need are individual tones at different frequencies. HERE is a link to some 1/6 octave sine wave tones that you can use. There are also some sweeps included. And there is a sample/example Excel spreadsheet that you can use to graph your measurements if you have Excel. The Excel spreadsheet will properly take into account the correction factors necessary for the Radio Shack SPL meter, if that is what you are using. Just delete the current values that are there, and insert your own measurements. Do not worry about the pre- and post-BFD measurements as these are measurements of that particular sub and room after the application of equalization utilizing a Behringer Feedback Destroyer. You can simply delete the post-BFD values so that that graph doesn't show up.


Sweet!

Play the given frequency then recored in the Raw SPL field. After I get the graph am I looking to get everything as close to 75 DB as possible? My Onkyo offers manual EQualization or the sub at 40, 80 and 160HZ. Not many points but it's better than nothing.


Crossover frequencies adjustments available for the mains are 80, 250, 800,2500 and 8000HZ. Do you happen to have these tones?
 

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Quote:
Originally Posted by dlenart25 /forum/post/14269784


Sweet!

Play the given frequency then recored in the Raw SPL field. After I get the graph am I looking to get everything as close to 75 DB as possible?

Basically, yes. Ideally, you want them as close to some common value as possible. Realize that this is usually not even anywhere close to possible without EQ and/or room treatments. But you can at least see how your sub, speakers, and sub+speakers behave at different crossover settings.


Quote:
Originally Posted by dlenart25 /forum/post/14269784


My Onkyo offers manual EQualization or the sub at 40, 80 and 160HZ. Not many points but it's better than nothing.

I'm not sure I understand the "or". They are separate adjustments, no? Don't you mean AutoEQ versus manual EQ?


Quote:
Originally Posted by dlenart25 /forum/post/14269784


Crossover frequencies adjustments available for the mains are 80, 250, 800,2500 and 8000HZ. Do you happen to have these tones?

Again, what you are saying is puzzling to me. I think you mean that those are the frequencies which can be EQ'd by the receiver either automatically or manually, correct? Not the crossover settings.


And those are the only tones I have. You can download a program which will generate tones for you, though. But those tones should be sufficient for you to measure the critical low-end region around and below the crossover setting.


And, yes, which ONKYO do you have?


If it has autocalibration and autoEQ capability, by all means, use it. The AutoEQ is there to help flatten your FR for you. It should also set your crossover setting(s) at what (it thinks) is best. Of course, it is not perfect. If you want to use your own preferred crossover setting(s) and do the measurements and EQ yourself, that is OK, too. But the AutoEQ can simplify things considerably and you should still be able to apply it even if you override the crossover setting(s) the receiver automatically chooses.
 

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Discussion Starter #12
I meant "of" not "or"


And yes I mean EQ frequencies not crossover frequencies. My apologies.


I will run the auto EQ (Audyssey) tonight. i ran it a long time ago and it gave me a crossover frequency of 200HZ so I thought why should I trust the EQ settings, right? Anyway, going to take a break now, getting frustrated.


BTW I have a Onkyo HTR 550 receiver part of a home theather in a box deal SR 800 or something like that. I also have a Yamaha RX-V661 laying around downstairs, but strangely I never really like the way that sounded even though istsupposedly has buhr brown DACS and offers passthrough audio with HDMI. Maybe I set that up wrong who knows. Maybe I'm just looking for too much when in reality my equipment isn't enough to get me to where I want to go


Anway, I'll get back with you tonight after I run Audyssey.
 

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BTW, those frequencies you listed - 40, 80, 160, 250, 800, 2500, and 8000 - are the same frequencies used by Audyssey when it autoEQs. You can also adjust the same frequencies manually if you desire. But I would let Audyssey "do its thing" before you begin adjusting the settings manually.
 

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Don't forget about the correction factors for the RS SPL meter. While not perfect, using them will give better results than not using them.


Fluctuations are best tamed by positioning of the speakers/sub and with room treatments. EQ is the least recommended way, but also is probably the most common way. It's generally not recommended to try to boost/flatten dips using EQ because that takes much power. You're better off to cut the peaks and in that regard EQ can help sans room treatments.


Since you have a computer and a SPL meter, you can get much more scientific about it by throwing Room EQ Wizard into the mix. Searching the Internet will give many hits on it.
 

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Along with the things posted above - most important IMO are to measure the room, and room treatments - I suggest you measure the room with just your mains firing, then measure again with just your subwoofer. You might find a sweet spot for the cross over using this method (though it appears your receiver does not allow many options in this area). No speaker measures the same in every room, and, where it placed in the room.

You might get benifit just from moving your speakers around a little.

Does your sub offer a phase setting? After optimizing things for you mains and sub seperately the phase setting of the sub can be useful to get things as coherent as possible through the critical cross over area- maybe your reciever can automatically take care of this for you though the "distance" measurement. Proper integration of subs and mains is not trivial - the "rules" provide a useful starting point.


btw ALL rooms need broadband bass absorption. You might be amazed by how the bass tightens up by putting a few absorbers in the room corners.
 

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Quote:
Originally Posted by whoaru99 /forum/post/14273445


Don't forget about the correction factors for the RS SPL meter. While not perfect, using them will give better results than not using them.

Yeah, the package of tones includes an Excel spreadsheet that will apply the correct correction factors prior to graphing the results, but if you can't use Excel or just simply need them, HERE are the most commonly used correction factors.
 

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Quote:
Originally Posted by dlenart25 /forum/post/14268595


I believe I mentioned, but becuase of the jumbled and reasonably long and confusing post it could have easily been missed. Here is a sketch of my setup. You will see the 12" velodyne is right next to the opening for the kitchen. I have played around with location on both sides of the TV stand but that corner on the other side just gets crazy boom. In it's current location I hardly get any localization even at 150Hz.






Lastly, if you wouldn't mind looking over this frequency graph it appears that it only remains flat down to about 150hz and it goes down from there to 75hz at -3DB:
http://www.aperionaudio.com/catalog/...x?versionid=36


And then this manual (Look at the specs for the 12" version) : http://www.velodyne.com/products/man...nglish_web.pdf


So basically we have a sub that hits the -3DB rule at 120HZ and a bookshelf that hits the -3DB rule at 75HZ. Would you still suggest the 100HZ crossover in this scenario?


One other important thing to note is that I have surrounds that hit the -3DB point at 120HZ.


The thing that got my attention was how much cleaner my bookshelves sounded with the 150HZ setting vs the lower settings.


thanks for taking the time to read that mess. I'm just wondering if I would have gotten better integration by going with a smaller 10" sub or if my setup is less than ideal.

I would move the sofa 5 feet forward and try it. Looks like you are too far away, especially with that sub next to the Kitchen. I understand that the room setup maybe more important then HT. You could move the sub over to the other side and get a sub eq and try to tame the boom.
 

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Quote:
Originally Posted by sivadselim /forum/post/14274579


Yeah, the package of tones includes an Excel spreadsheet that will apply the correct correction factors prior to graphing the results, but if you can't use Excel or just simply need them, HERE are the most commonly used correction factors.

is there a more complete list? I am getting ready to run an analysis using many more than these 12 tones.


thank you,

jp
 

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Quote:
Originally Posted by BigJPDC /forum/post/14284536


is there a more complete list? I am getting ready to run an analysis using many more than these 12 tones.

Complete list of what? The correction factors? You can extrapolate as to what the correction factor value is for particular frequencies. Or just graph the correction factor values versus frequency.


If you do a web search you will find quite a bit of discussion about it as well as a more thorough list.
 

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If you want individual frequency test tones, you can use the RealTraps tones:
http://www.realtraps.com/test-cd.htm


However, I would just use Audyssey. It measures the actual -3 dB point of your speakers in your room and sets the crossover accordingly. If it selected 200 Hz for the mains, it is because, in YOUR ROOM, the bass response of at least one of your mains was dropping off well above it's rated -3 dB point. This is usually caused by the room and the listening position more than the speaker. There is a very active Audyssey thread, and the lead designer of the system posts there all the time. He is extremely helpful:
http://www.avsforum.com/avs-vb/showthread.php?t=795421


I also agree that you should consider moving your sofa forward and get it away from the back wall. You may eliminate the null that is causing Audyssey to set the crossover so high. Then consider moving your side surrounds forward so they are at the recommended 90 to 100 degrees:
http://www.dolby.com/consumer/home_e...omlayout2.html


Craig


Edit: I just looked at your diagram again, and it may not be possible to move your sofa forward. In that case, try moving the sub to the other side of the TV. Also, try moving your speakers a little. You are most likely getting significantly different room reinforcement of the right speaker due to it's corner placement vs. the left speaker's open space placement.
 
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