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Two Subs...Gain Matching vs Level Matching - Page 5

post #121 of 202
Quote:
Originally Posted by craig john View Post

They both have the Onkyo 809 which has XT. In those models with XT and dual sub outs, they are just an internal Y connection. Audyssey "sees" them as one sub. It does *not* set different levels and distances for each sub. Therefore, if they gain-match the subs, they will remain gain-matched after Audyssey has its' way with them.

Craig

Thanks much for verifying this....it appears I did it correctly.

I set each first at 75DB in the SAME exact location...my digital reading on my sub said -20db for both subs.

When I then re-ran audyssey with BOTH running, it then reporting 78DB I think, I turned EACH sub down to -23DB I THINK and then my Audyssey was reading the proper 75DB...

Away I went and looks like I am setup best I can...

Thanks much...great thread!

Gear mentioned in this thread:

post #122 of 202
Quote:
Originally Posted by toofast68 View Post

Thanks much for verifying this....it appears I did it correctly.

I set each first at 75DB in the SAME exact location...my digital reading on my sub said -20db for both subs.

When I then re-ran audyssey with BOTH running, it then reporting 78DB I think, I turned EACH sub down to -23DB I THINK and then my Audyssey was reading the proper 75DB...

Away I went and looks like I am setup best I can...

Well, without knowing a little bit more it is hard to say whether you did it correctly or not. Based upon your description (both at 75dB, then adding to be 78dB), it sounds like maybe not. This sounds a lot like level-matching. But, again, without knowing more, it is hard to tell from your description. I realize you say you measured them in the same location.

The whole purpose of the initial measurements is to get the subs gain-matched. And the reason you must do it this way is because, unfortunately, you can't just assume that the volume pots and scales on the knobs are accurate and consistent enough from sub to sub to simply assume that an identical settings on each sub equals identical gain settings. If it wasn't for this, you could just set both subs at the same setting and be done with the gain-matching step.

But these initial gain-matching measurements should be done on both subs, identically, with the meter/mic very close to the subs and, preferably, with the subs away from any boundaries (except the floor, which can't be avoided). It is VERY important that they be measured absolutely identically. Any variation in the position of the meter/mic will affect the results. The absolute dB reading at this stage is not important although how you do this IS going to affect the results you get once you move the subs into position, move the meter/mic to your listening spot(s), and run Audyssey (or calibrate manually). So it may take some trial and error. What is important is that they be outputting the exact same SPL when measured this way.
post #123 of 202
Hmm Im interested in this gain matching stuff but what confuses me is what if your room is not ideal? Like one of my subs will be placed on the right side of the LP and is an open area compared to the second sub which is on the left side and near a corner?
post #124 of 202
Quote:
Originally Posted by pokekevin View Post

Hmm Im interested in this gain matching stuff but what confuses me is what if your room is not ideal? Like one of my subs will be placed on the right side of the LP and is an open area compared to the second sub which is on the left side and near a corner?

Best case for gain matching. Unequal distance from the LP in different locations make gain matching a better option then level matching.
post #125 of 202
Quote:
Originally Posted by pokekevin View Post

Hmm Im interested in this gain matching stuff but what confuses me is what if your room is not ideal? Like one of my subs will be placed on the right side of the LP and is an open area compared to the second sub which is on the left side and near a corner?

The whole point of gain-matching is that you want each sub to drive the room with equal power. This will ensure that both subs have the same headroom and neither will hit it's limits before the other. The size or shape of the room is immaterial to the gain-matching technique, as is the listening position in the room.

Craig
post #126 of 202
Silly question but I assume than it would be wise to have similar subs when gain matching in my situation?
post #127 of 202
Quote:
Originally Posted by sivadselim View Post

Well, without knowing a little bit more it is hard to say whether you did it correctly or not. Based upon your description (both at 75dB, then adding to be 78dB), it sounds like maybe not. This sounds a lot like level-matching. But, again, without knowing more, it is hard to tell from your description. I realize you say you measured them in the same location.

If he measured them in the same location and matched the gains, then moved them back to their in-room positions... and they both, coincidentally, measured 75 dB, then his is a situation where gain-matching yields the same result as level-matching. The fact that they summed to 78 dB seems correct for non-co-located subs. Turning both of them down the same amount to get 75 dB also seems correct.

Quote:
Originally Posted by sivadselim View Post

The whole purpose of the initial measurements is to get the subs gain-matched. And the reason you must do it this way is because, unfortunately, you can't just assume that the volume pots and scales on the knobs are accurate and consistent enough from sub to sub to simply assume that an identical settings on each sub equals identical gain settings. If it wasn't for this, you could just set both subs at the same setting and be done with the gain-matching step.Exactly!

But these initial gain-matching measurements should be done on both subs, identically, with the meter/mic very close to the subs and, preferably, with the subs away from any boundaries (except the floor, which can't be avoided). It is VERY important that they be measured absolutely identically. Any variation in the position of the meter/mic will affect the results. The absolute dB reading at this stage is not important although how you do this IS going to affect the results you get once you move the subs into position, move the meter/mic to your listening spot(s), and run Audyssey (or calibrate manually). So it may take some trial and error. What is important is that they be outputting the exact same SPL when measured this way.

Exactly!

Craig
post #128 of 202
Caveot: I haven’t read this entire thread and my comments below pertain to 2 channel stereo.

Allow me to do some shameless stirring of the pot . . .

I believe that you don’t need to strive to match 2 or more sub’s output gains or loudness levels, and if it ends up that they do match then it’s likely a fluke or a mistake. To assume that each sub’s gain or levels should be identical only works if they’re co-located to minimize distortion so that their combined sound sounds like a unified sound field – you wouldn’t want one belting out and distorting while the other is loping along. I would think that the other condition when both subs gain/levels ought to be identical is when the room in which they’re placed is perfectly symmetrical and the subs are across from each other or when 4 are set up in some symmetrical arrangement.

Baring the two situations above, I’d have to believe that most domestic rooms are anything but symmetrical. As such, bass reproduction in small rooms is a crap shoot at best. As a result subs will need to be spread throughout the room to vary the amount of energy transferred to bass modes; one sub may be located at or near a pressure minimum of the offending bass wave whereas another 1 or 2 subs could be located to drive another offending wave destructively or constructively. Because subs will be at different places along the length, width, and height dimensions and experiencing differing levels of adjacent-boundary gain based on the wall construction vs floor construction or distance from a surface, there are too many variables at play to say
“one size fits all” and to gain/level match all subs. Instead, an optimization process needs to happen which means each sub could well have it’s own cross-over point, phase and volume setting such that the summation of all subs outputs delivers the desired bass frequency response at the listening position(s). Sub direction, distance from sitting position, and phase are other variables to contend with which imply striving for gain or level matching isn’t the right approach to the problem.

Dr Geddes promotes near-random sub placement and goes further to suggest that all subs should NOT be identical which would make matching gain setting troublesome. Todd Welti and Allan Devantier began developing ‘sound field management’ back in 2003 where each sub’s controls are set independantly to optimize the desired bass response in totality. Then there is the “Double Bass Array” technique which mounts 4 subs on the front wall each ¼ the room width away from side walls and ¼ the room height away from the floor and ceiling while the rear wall has mirror imaged subs located and 180 degrees out of phase. In this situation all subs may need to be gain matched.

So in summary, without the sophisticated software for iterative modeling, we can only hope to arrive at or near the same end-point of bass optimization by fine-tuning one sub first and then adding the effects of an additional sub, and so on and with plenty of tinkering and fine tuning which makes gain / level matching not so important. Of course, 1/24th octave smoothing or more granular acoustic measurment tools are helpful to get us to the desired end state (e.g. house curve, flat frequ).
post #129 of 202
Quote:
Originally Posted by craig john View Post


You need to get an SPL and follow the suggestions in Post #5 of this thread.

Once you've gain-matched them, if they still read higher than 75 dB at the LP before running Audyssey, then just turn each sub down an exactly equal amount. You'll still be gain-matched, and Audyssey will set the subwoofer trim in the appropriate range.

Craig

what a about the concept in beginning posts that stated to use a higher db setting since mlp will be further away then center of room?

Consensus on this?
post #130 of 202
Quote:
Originally Posted by pokekevin View Post

Hmm Im interested in this gain matching stuff but what confuses me is what if your room is not ideal? Like one of my subs will be placed on the right side of the LP and is an open area compared to the second sub which is on the left side and near a corner?

That's fine. Even if one sub is 2' away, next to your listening position, and the other is 15' away, in the corner of the room, it's fine. Might one sub be seemingly louder than the other? Yes. If that seems improper or bothers you, then level matching might be a better approach for you. But, even though their apparent or perceived volumes at the listening spot may be identical after level matching, you will probably end up adjusting the subs to two very different output levels when you level match in this sort of situation.

The goal of gain matching is that each sub works (literally) identically. With EQ and room treatment, the disparity in their apparent or perceived volumes can theoretically be overcome, or at least diminished. In an ideal (or idealized) circumstance, as long as you are crossing them over low enough, that one sub is louder at the listening spot should not, theoretically, be perceivable as the contribution of both (or more) subs is simply to the overall bass in the room.
post #131 of 202
Quote:
Originally Posted by craig john View Post

If he measured them in the same location and matched the gains, then moved them back to their in-room positions... and they both, coincidentally, measured 75 dB, then his is a situation where gain-matching yields the same result as level-matching. The fact that they summed to 78 dB seems correct for non-co-located subs. Turning both of them down the same amount to get 75 dB also seems correct.

I know, but it just seemed too 'pat'. How could they measure near-field at 75dB, then moved into position and measure essentially the same (albeit summed, 78dB) level from the listening position? Seemed like maybe, even though he moved them into the same spot, he was doing the gain matching measurements from the listening spot with each sub placed at one of the sub's final resting places. I think it might be possible to gain match them this way. Just not the best and "most rigorous method".
post #132 of 202
Quote:
Originally Posted by kevinzoe View Post

Caveot: I haven't read this entire thread and my comments below pertain to 2 channel stereo.

Allow me to do some shameless stirring of the pot . . .

I believe that you don't need to strive to match 2 or more sub's output gains or loudness levels, and if it ends up that they do match then it's likely a fluke or a mistake. To assume that each sub's gain or levels should be identical only works if they're co-located to minimize distortion so that their combined sound sounds like a unified sound field - you wouldn't want one belting out and distorting while the other is loping along. I would think that the other condition when both subs gain/levels ought to be identical is when the room in which they're placed is perfectly symmetrical and the subs are across from each other or when 4 are set up in some symmetrical arrangement.

Baring the two situations above, I'd have to believe that most domestic rooms are anything but symmetrical. As such, bass reproduction in small rooms is a crap shoot at best. As a result subs will need to be spread throughout the room to vary the amount of energy transferred to bass modes; one sub may be located at or near a pressure minimum of the offending bass wave whereas another 1 or 2 subs could be located to drive another offending wave destructively or constructively. Because subs will be at different places along the length, width, and height dimensions and experiencing differing levels of adjacent-boundary gain based on the wall construction vs floor construction or distance from a surface, there are too many variables at play to say one size fits all and to gain/level match all subs. Instead, an optimization process needs to happen which means each sub could well have it's own cross-over point, phase and volume setting such that the summation of all subs outputs delivers the desired bass frequency response at the listening position(s). Sub direction, distance from sitting position, and phase are other variables to contend with which imply striving for gain or level matching isn't the right approach to the problem.

Dr Geddes promotes near-random sub placement and goes further to suggest that all subs should NOT be identical which would make matching gain setting troublesome. Todd Welti and Allan Devantier began developing sound field management' back in 2003 where each sub's controls are set independantly to optimize the desired bass response in totality. Then there is the Double Bass Array technique which mounts 4 subs on the front wall each ¼ the room width away from side walls and ¼ the room height away from the floor and ceiling while the rear wall has mirror imaged subs located and 180 degrees out of phase. In this situation all subs may need to be gain matched.

So in summary, without the sophisticated software for iterative modeling, we can only hope to arrive at or near the same end-point of bass optimization by fine-tuning one sub first and then adding the effects of an additional sub, and so on and with plenty of tinkering and fine tuning which makes gain / level matching not so important. Of course, 1/24th octave smoothing or more granular acoustic measurment tools are helpful to get us to the desired end state (e.g. house curve, flat frequ).

I think this is a very reasonable and valid post. And this is just another way of doing things. Each method has its own merits and I think what one chooses to use depends upon the exact situation; what their measuring and EQ capabilites are, how much room treatment they are willing to utilize, and how much effort they are willing to expend. With dissimilar subs, the Geddes method may be best by default. And you could argue that identical subs shouldn't really present a different situation, as the subs will most likely not perform identically in-room whether level-matched OR gain-matched. They'll behave like dissimilar subs.

But gain matching or level matching are not really "flukes". The subs ARE adjusted to have either identical levels OR identical gains (not both). I do agree that post-EQ they may no longer be level-matched or even gain-matched if checked post-EQ with the same tone that was initially used to level or gain match the subs.

But it seems you might think that level and gain matching are the same thing. In a situation where "the room in which they're placed is perfectly symmetrical and the subs are across from each other or when 4 are set up in some symmetrical arrangement", gain matched subs might also be level-matched subs and vice versa. But otherwise, they are two very different approaches. With gain matching there is no chance that one sub is "belting out and distorting while the other is loping along". That is the whole point. Both subs are adjusted to the exact same gain setting so they 'work' identically. And with level matching, the asymmetry, dissimilar distances, and unequal room effects are compensated for by adjusting each sub's individual, perceived volume or contribution at the listening spot to be identical. Compensating for these differences is one of the main goals or points of level-matching.

They are completely different approaches. With gain matching the subs' outputs are adjusted to be identical but the perceived volume or contribution of each sub at the listening spot can be very different. And with level matching the subs' outputs can be very dissimilar but the perceived volume or contribution of each sub at the listening spot is identical.
post #133 of 202
Might be useful if you have inadequate subs but otherwise just let your EQ level match. Waste of time for most.
post #134 of 202
Quote:
Originally Posted by Gary J View Post

IMO Might be useful if you have inadequate subs but otherwise just let your EQ level match. Waste of time for most.

I fixed your post for you Gary. Since when did Craig's 3 SubMs become inadequated.
post #135 of 202
Quote:
Originally Posted by sivadselim View Post

I know, but it just seemed too 'pat'. How could they measure near-field at 75dB, then moved into position and measure essentially the same (albeit summed, 78dB) level from the listening position? Seemed like maybe, even though he moved them into the same spot, he was doing the gain matching measurements from the listening spot with each sub placed at one of the sub's final resting places. I think it might be possible to gain match them this way. Just not the best and "most rigorous method".

Well, perhaps I didn't do things correctly....but I will try again,.

1) connected sub 1 ONLY
2) placed in center of ROOM near the listening "mic"
3) adjusted to 75DB
4) repeated the same thing with sub 2 - of course in the same place with sub 1 disconnected.
5) moved BOTH subs to final resting place
6) connected them both
7) ran audyssey - SWEAR my reading was 78DB, so adjusted EACH sub EXACTLY the same to get a unified reading of 75DB with mic placed in listening position #1
8) finished setup etc.

NOW - I am new to subs and ONLY used this method as I really was confused on everything else and this made sense ?

I honestly don't know if this is best...but at the moment until I learn more I guess it is what I am going with.
post #136 of 202
Quote:
Originally Posted by toofast68 View Post

Well, perhaps I didn't do things correctly....but I will try again,.

1) connected sub 1 ONLY
2) placed in center of ROOM near the listening "mic"
3) adjusted to 75DB
4) repeated the same thing with sub 2 - of course in the same place with sub 1 disconnected.
5) moved BOTH subs to final resting place
6) connected them both
7) ran audyssey - SWEAR my reading was 78DB, so adjusted EACH sub EXACTLY the same to get a unified reading of 75DB with mic placed in listening position #1
8) finished setup etc.

NOW - I am new to subs and ONLY used this method as I really was confused on everything else and this made sense ?

I honestly don't know if this is best...but at the moment until I learn more I guess it is what I am going with.

Your experience with RS meter readings was completely random, as it is for everyone else.

The missing equation here is a frequency response measurement.

The rumble tone in every AVR is a bandwidth-limited pink noise from 30-100 Hz.

The SPL meter does not have a flat response in that same bandwidth.

If, for example, the frequency response at your mic with the sub in the gain matching position shows a peak at 30 Hz you will get an SPL meter reading that's dominated by that peak. With a correction factor of anywhere between +4dB to +6dB at 30 Hz for the RS meter, you can see where I'm coming from here.

Using the same example, moving the subs into position will usually drastically change the FR and you might see a very large swing in your meter reading.

Audyssey will then set your sub output hot... every time, any system. This is simply because the Aud mic has a roll off which sends a false reading to its brain. That roll off gets compensated for, resulting in a boost to the level that mirrors the mic roll off.

Since the mic roll off occurs from 30 Hz down, the boost will show up in that bandwidth skewing the SW output level.

These differences from the meter reading from the gain matching FR to the meter reading from the final resting place FR to the Aud compensation from its algorithm/mic roll off are significant, making most of this threads nit-picking moot.

Regardless of the preferred level matching method, a FR sweep is the only reliable method to gauge levels, especially after running Audyssey.

For reference, I've compared the Aud mic response to my reference ACOPacific mic (which is flat to 2 Hz with no calibration file).

I've compared close mic measurements of before and after running Aud to confirm that it a) boosts both sides of a peak instead of just pulling down the peak and b) boosts the low end proportional to its mics roll off, which frequencies are not included in the rumble tone used by most for level calibration.

I've compared the RS meter reading using the rumble tone to a frequency response with the measurement mic and the RS meter at exact positions. The result is always that the rumble tone/RS meter level is higher than the flat frequency response method, by +4-6dB.

Bosso
post #137 of 202
Quote:
Originally Posted by Gary J View Post

Might be useful if you have inadequate subs but otherwise just let your EQ level match. Waste of time for most.

Not sure what you are referring to. What "might be useful"? Gain matching? What does "inadequate subs" have to do with anything?

Most people do not have an EQ that can level match 2 subs. AFAIK, only MultEQ XT32 can level match and EQ 2 subs separately. And if you have more than 2, even MultEQ is no help. So, for most, level-matching must be done manually. Were it not for the fact that you can't just assume that identical volume settings on two identical subs yields the exact same gain, gain matching would be a piece of cake. Just set the subs at the same exact setting and calibrate.
post #138 of 202
Quote:
Originally Posted by toofast68 View Post

Well, perhaps I didn't do things correctly....but I will try again,.

1) connected sub 1 ONLY
2) placed in center of ROOM near the listening "mic"
3) adjusted to 75DB
4) repeated the same thing with sub 2 - of course in the same place with sub 1 disconnected.
5) moved BOTH subs to final resting place
6) connected them both
7) ran audyssey - SWEAR my reading was 78DB, so adjusted EACH sub EXACTLY the same to get a unified reading of 75DB with mic placed in listening position #1
8) finished setup etc.

NOW - I am new to subs and ONLY used this method as I really was confused on everything else and this made sense ?

I honestly don't know if this is best...but at the moment until I learn more I guess it is what I am going with.

OK, sorry I questioned you.

But, how did you "adjusted EACH sub EXACTLY the same to get a unified reading of 75DB with mic placed in listening position #1"? You should do this with the AVR's subwoofer channel level trim. Not with the sub's own individual volume knobs. That way the subs definitely remain gain matched and you bring their combined volume down to the correct level in unison.
post #139 of 202
Quote:
Originally Posted by bossobass View Post

Regardless of the preferred level matching method.............

He's gain matching. And provided he did what he says he did, carefully, they ARE gain matched.
post #140 of 202
Quote:
Originally Posted by toofast68 View Post

Well, perhaps I didn't do things correctly....but I will try again,.

1) connected sub 1 ONLY
2) placed in center of ROOM near the listening "mic"

This needs to a "close mic'd" measurement, with the mic within an inch or two of the driver. This eliminates the room interactions.

Quote:


3) adjusted to 75DB

I usually find that with a close mic'd measurement, I need to set the levels to 85-90 dB so that when I set the subs back in place, I get something closer to 75 dB.
Quote:


4) repeated the same thing with sub 2 - of course in the same place with sub 1 disconnected.
5) moved BOTH subs to final resting place
6) connected them both
7) ran audyssey - SWEAR my reading was 78DB, so adjusted EACH sub EXACTLY the same to get a unified reading of 75DB with mic placed in listening position #1
8) finished setup etc.

NOW - I am new to subs and ONLY used this method as I really was confused on everything else and this made sense ?

I honestly don't know if this is best...but at the moment until I learn more I guess it is what I am going with.

How does it sound?

Craig
post #141 of 202
Quote:
Originally Posted by craig john View Post

This needs to a "close mic'd" measurement, with the mic within an inch or two of the driver. This eliminates the room interactions.


I usually find that with a close mic'd measurement, I need to set the levels to 85-90 dB so that when I set the subs back in place, I get something closer to 75 dB.

How does it sound?

Craig

Ok, well I a not sure I did the mic close enough...

BUT it does sound pretty awesome...I have 2 identical subs and the sound field is very nice and I get nice even coverage with an outstanding movie experience.

Perhaps I will setup again and see if I can do better.
post #142 of 202
Quote:
Originally Posted by toofast68 View Post

Ok, well I a not sure I did the mic close enough...

BUT it does sound pretty awesome...I have 2 identical subs and the sound field is very nice and I get nice even coverage with an outstanding movie experience.

Perhaps I will setup again and see if I can do better.

Just out of curiosity, how close to being set identically did the sub's own individual volume settings come out to be after you gain matched them? What are your subs (forgive me if you have already stated this earlier in the thread)?
post #143 of 202
Quote:
Originally Posted by sivadselim View Post

Just out of curiosity, how close to being set identically did the sub's own individual volume settings come out to be after you gain matched them? What are your subs (forgive me if you have already stated this earlier in the thread)?

They came out EXACTLY

I have a pair of Klipsch Reference RW-12d and they have a DIGITAL setup interface.

So each sub measured on the meter 75DB at a -20DB setting on the sub itself. So I guess that is a good thing ??
post #144 of 202
Quote:
Originally Posted by toofast68 View Post

So I guess that is a good thing ??

Yep.

Although that they have the same exact gain settings is not really definitive, it sounds like you probably did everything properly.

Now, again out of curiosity, can I ask, how symmetrical is your room's layout and your subs' placement relative to that layout? Also, have you tried comparing the subs' relative individual in-room levels, now, as measured from the listening spot?
post #145 of 202
Quote:
Originally Posted by sivadselim View Post

Yep.

Although that they have the same exact gain settings is not really definitive, it sounds like you probably did everything properly.

Now, again out of curiosity, can I ask, how symmetrical is your room's layout and your subs' placement relative to that layout?

It AIN't at all...

I attached a few pics just for fun. I have a REALLY tough room as well.

Sub 1 is front wall to the left of the center channel.
Sub 2 is back left rear wall - if you are looking at the pics...so if you are facing the screen one sub is left front....the other is rear right.
LL
LL
LL
post #146 of 202
Quote:
Originally Posted by toofast68 View Post

It AIN't at all...

I attached a few pics just for fun. I have a REALLY tough room as well.

Sub 1 is front wall to the left of the center channel.
Sub 2 is back left rear wall - if you are looking at the pics...so if you are facing the screen one sub is left front....the other is rear right.

Oh, nice, a great example of a completely asymmetric layout. So, have you tried comparing the subs' relative individual in-room levels, now, as measured from the listening spot? Just curious how far away from being level matched they ended up being. A quick and dirty measurement of a test tone with each sub individually would be all that it would take. The actual level doesn't really matter. Just their relative levels.
post #147 of 202
Quote:
Originally Posted by sivadselim View Post

Oh, nice, a great example of a completely asymmetric layout. So, have you tried comparing the subs' relative individual in-room levels, now, as measured from the listening spot? Just curious how far away from being level matched they ended up being. A quick and dirty measurement of a test tone with each sub individually would be all that it would take. The actual level doesn't really matter. Just their relative levels.

I have not....but it is something I will remind myself to do. I really struggled with the placement, and it is the best I could come up with.
I guess I COULD have placed them BOTH on the front wall, but I think where I ended up added some real dynamic "feeling" to the rear seating position, while maintaining the balance of the source.
post #148 of 202
Quote:
Originally Posted by toofast68 View Post

I have not....but it is something I will remind myself to do. I really struggled with the placement, and it is the best I could come up with.
I guess I COULD have placed them BOTH on the front wall, but I think where I ended up added some real dynamic "feeling" to the rear seating position, while maintaining the balance of the source.

I think you're fine. Although, intuitively, placing them symmetrically along the front wall may seem correct, it is really not necessarily so. With the completely different placement you might even stand a greater chance of evening out room anomalies.

If it sounds good to you, that's really all that matters. Whether you level matched or gain matched, even, is not so hugely important. That you had a rationale for what you chose, that you are comfortable with, is all that really matters.

Enjoy!
post #149 of 202
Quote:
Originally Posted by sivadselim View Post

I think you're fine. Although, intuitively, placing them symmetrically along the front wall may seem correct, it is really not necessarily so. With the completely different placement you might even stand a greater chance of evening out room anomalies.

If it sounds good to you, that's really all that matters. Whether you level matched or gain matched, even, is not so hugely important. That you had a rationale for what you chose, that you are comfortable with, is all that really matters.

Enjoy!

Right on, I've really enjoyed this thread and I am always willing to learn...so thanks again to all !
post #150 of 202
I also agree this thread is awesome.

So, after countless days of researching these threads, I was able to figure where I wantEd my 2 subs and how to configure it.

I have 2 brand new pa120 subs. I did the level gain concept as stated in this thread. Placed spl meter next to sub in center of room on top of a subdude. Set sub volume trim to get 85db. This was repeated for second sub. Both turned out to have volume dial at 4 (1-10). I then placed subs in back right corner and front left corner. Couch is against back wall. (waf) :'(
I then ran ady. And mic was reading 80db. I left the volume trims alone. Ran all 8 positions. Room fills with bass on little tests so far. Wife is home with migraine, so tomorrow is a new day.

With the calibration, the sub trim was set to -4.5. Could I raise this just since I like more bass?

With all said, did I do everything correct? Thanks again Craig and company.
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