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SVS AS-EQ1 Thoughts... - Page 205

post #6121 of 6280
Quote:
Originally Posted by AustinJerry View Post


- What subs do you have?

@Kimwin

Now that I see you have ULS-15's like I do, I know something is wrong. I drive my ULS-15's pretty hard, and I never hear clipping. Looking forward to your answers.
post #6122 of 6280
Quote:
Originally Posted by Kimwyn View Post

Aaaaaaahhhhhhhh......... I totally get you. And my subs' trim level did produce 75dB on the meter. So why then is my sub bottoming? I have dual ULS-15s equidistant to the main LP but the one on the right is set to 12 o clock and that is the one that is bottoming.

OK, now I understand. I suspect that the sub on the right is situated in a room null, which means that you would need to raise the gain on that sub significantly higher in order to achieve the 75dB level at the beginning of the calibration. This results in that sub being over-drived during heavy bass passages, resulting in clipping, or bottoming out. In order to correct this situation, you need to move the sub out of the null, which will allow you to lower the gain. Do you have measurement tools that would allow you to measure whether the sub is indeed sitting in a null? Do you have options for placing the sub in a different spot? Recall that the AS-EQ1 will compensate if the subs are not equidistant from the MLP.

For my ULS-15's, I always "gain-match" the subs before running Audyssey, and I don't change the sub gain settings at the beginning of the calibration. This ensures that no sub gain is set too high relative to the others. I have a link to the gain-matching procedure, if you need it.
post #6123 of 6280
Quote:
Originally Posted by Kimwyn View Post

Aaaaaaahhhhhhhh......... I totally get you. And my subs' trim level did produce 75dB on the meter. So why then is my sub bottoming? I have dual ULS-15s equidistant to the main LP but the one on the right is set to 12 o clock and that is the one that is bottoming.

What is the subwoofer trim level setting in your receiver set for? What kind of receiver or pre/pro are you using?
post #6124 of 6280
If Kimwin needs to set the gain level on his right sub at a higher level in order to reach 75dB in the first step of the calibration, then that sub is sitting in a null relative to the left sub. During heavy bass passages, the right sub needs to work significantly harder, resulting in either clipping or bottoming-out. The solution is to move the sub out of the null. Pretty simple. Waiting for Kimwin to confirm.
post #6125 of 6280
Quote:
Originally Posted by Kimwyn View Post

I was wondering guys, after the unit has performed its job, can I just lower the gains on the back of the subs? My subs keep sounding like they are bottoming or clipping ( I don't know the difference between the two but I know the noise I get isn't right and it's because of how high the gains are on the subs as the unit advises to Put the gains at 12 o clock) so can I simply take the gains down on the subs after I run the eq1?


You can alter the gain on the subs after EQ - but it's much better to adjust them in your AVR trim menu - makes it easier to know what you've done and to go back and forth if you need to.

 

f)4.   If I want to run my subs a little 'hot' where should I make the changes?

 

HST, you shouldn't need to. Did you get the subs gain controls set right to begin with?

 

f)3.   How do I set the controls on my subwoofer before running MultEQ?

post #6126 of 6280

Originally Posted by Kimwyn View Post

I was wondering guys, after the unit has performed its job, can I just lower the gains on the back of the subs? My subs keep sounding like they are bottoming or clipping ( I don't know the difference between the two but I know the noise I get isn't right and it's because of how high the gains are on the subs as the unit advises to Put the gains at 12 o clock) so can I simply take the gains down on the subs after I run the eq1?


You can alter the gain on the subs after EQ - but it's much better to adjust them in your AVR trim menu - makes it easier to know what you've done and to go back and forth if you need to.

 

f)4.   If I want to run my subs a little 'hot' where should I make the changes?

 

HST, you shouldn't need to. Did you get the subs gain controls set right to begin with?

 

f)3.   How do I set the controls on my subwoofer before running MultEQ?

 

Originally Posted by Kimwyn View Post

Aaaaaaahhhhhhhh......... I totally get you. And my subs' trim level did produce 75dB on the meter. So why then is my sub bottoming? I have dual ULS-15s equidistant to the main LP but the one on the right is set to 12 o clock and that is the one that is bottoming.

 

SPL meters are notoriously unreliable for setting bass levels. Try the procedure detailed in the FAQ. You may need to back off the sub gain controls.

post #6127 of 6280
Quote:
Originally Posted by AustinJerry View Post

OK, now I understand. I suspect that the sub on the right is situated in a room null

Subs don't sit in nulls. Some listening positions may be in a null but without a lot more info I am suspecting a defective sub.
post #6128 of 6280
Ok Jerry, thanks for your help. The only problem is, I don't have another place to place the sub at the moment. I would need to buy some really long RCA cords to place them in an alternative position so until then they can't move. Thanks anyways and by the way, since we have the same subs could you pm me so we could discuss the set up?
post #6129 of 6280
Quote:
Originally Posted by Gary J View Post

Subs don't sit in nulls. Some listening positions may be in a null but without a lot more info I am suspecting a defective sub.

Thanks for your input as it is much appreciated but I do not suspect this to be the issue.
post #6130 of 6280
Oh I forgot to mention, the sub which bottoms is pulled into a power conditioner and whenever the scenes which may make the sub bottom come on, the "regulating" light clips on. That light usually comes on during heavy bass scenes and the light usually indicates heavy current draw. It's an APC J15 power conditioner. I was thinking I should simply plug the sub straight into the wall and see what happens.
post #6131 of 6280
Quote:
Originally Posted by Kimwyn View Post

Ok Jerry, thanks for your help. The only problem is, I don't have another place to place the sub at the moment. I would need to buy some really long RCA cords to place them in an alternative position so until then they can't move. Thanks anyways and by the way, since we have the same subs could you pm me so we could discuss the set up?


I have 4 ULS 15s. Use the wireless feature to move them around the room to get the ideal set up. Then once you've found it, You can hard wire them.
post #6132 of 6280
If the wireless feature would work for me then my situation would be so much better. The wireless simply never works for me and that annoys me because that was such a useful feature.
post #6133 of 6280
Quote:
Originally Posted by Kimwyn View Post

Ok Jerry, thanks for your help. The only problem is, I don't have another place to place the sub at the moment. I would need to buy some really long RCA cords to place them in an alternative position so until then they can't move. Thanks anyways and by the way, since we have the same subs could you pm me so we could discuss the set up?


It's easy to check for a defective sub simply by swapping them over, of course. I know you don't suspect the sub to be defective but as it's an easy swap, it might be worth doing.

post #6134 of 6280
Quote:
Originally Posted by Kimwyn View Post

Oh I forgot to mention, the sub which bottoms is pulled into a power conditioner and whenever the scenes which may make the sub bottom come on, the "regulating" light clips on. That light usually comes on during heavy bass scenes and the light usually indicates heavy current draw. It's an APC J15 power conditioner. I was thinking I should simply plug the sub straight into the wall and see what happens.


Good idea.

post #6135 of 6280
Quote:
Originally Posted by kbarnes701 View Post


Good idea.

Do you think that that can be the reason for the bottoming?
post #6136 of 6280
Quote:
Originally Posted by Kimwyn View Post

Quote:
Originally Posted by kbarnes701 View Post


Good idea.

Do you think that that can be the reason for the bottoming?


IDK. It was the light flickering on and off that interested me. I think that plugging it directly into the wall outlet is a good idea as it is so simple to test. Anything easy to test always seems worth testing to me.

 

My SVS subs have protection against overdriving them and they will cut out before they bottom out - yours don't seem to have this protection so it's easily possible that they could be bottoming if the gain is set too high, either on the sub or the incoming signal. As others have said, the best plan is to set the gain on the sub at 75dB and then run Audyssey and see where it sets the trim - ideally in the -3.5 to +3.5 dB range, or close to.  If you don't have any way to accurately check the sub gain, then run Audyssey at one position and then check the trims. Rinse and repeat as necessary until you get the sub trim to -3dB or thereabouts. Then you are good to go and you should not experience any bottoming out. If you do, then the sub may be faulty - but that is very easily ascertained by swapping the two subs over and seeing if the problem follows the sub or stays where it is. If you do that, be sure to set the gain and the trim on the other sub, when you swap it, to whatever it was on the suspect sub.

post #6137 of 6280
The ULs 15s do not have the built in protection that the SVS's do.
post #6138 of 6280
Quote:
Originally Posted by Gary J View Post

Subs don't sit in nulls. Some listening positions may be in a null but without a lot more info I am suspecting a defective sub.

? Of course they can be placed in nulls, or they can be placed where they excite modes, i.e. peaks. If one has complete placement freedom, the idea is to place them where they minimally interact with neither primary, secondary or tertiary peaks or nulls. With two subs in a rectangular room, and placement freedom, this concern goes away.

Jeff
post #6139 of 6280
Quote:
Originally Posted by pepar View Post

? Of course they can be placed in nulls, or they can be placed where they excite modes, i.e. peaks. If one has complete placement freedom, the idea is to place them where they minimally interact with neither primary, secondary or tertiary peaks or nulls. With two subs in a rectangular room, and placement freedom, this concern goes away.
Jeff

This is my thinking as well, Jeff. If Kimwin is adjusting the sub gains to display 75dB at the beginning of the AS-EQ1 calibration, and one sub has a significantly higher gain setting than the other, this would lead me to believe that sub should be moved to a different location. If he connects the subs wirelessly temporarily, he should be able to find a better sub placement, and then order physical cables if he prefers a wired connection.

Of course, this assumes that there isn't something physically wrong with the sub, which he could test out by swapping the two subs, as Keith recommended.
post #6140 of 6280
By swapping the subs what do you mean? Simply alternating the subs (place the one on the right on the left and vice versa)?
post #6141 of 6280
Quote:
Originally Posted by Kimwyn View Post

By swapping the subs what do you mean? Simply alternating the subs (place the one on the right on the left and vice versa)?

See Keith's post above.
post #6142 of 6280
Quote:
Originally Posted by AustinJerry View Post

This is my thinking as well, Jeff. If Kimwin is adjusting the sub gains to display 75dB at the beginning of the AS-EQ1 calibration, and one sub has a significantly higher gain setting than the other, this would lead me to believe that sub should be moved to a different location. If he connects the subs wirelessly temporarily, he should be able to find a better sub placement, and then order physical cables if he prefers a wired connection.
Of course, this assumes that there isn't something physically wrong with the sub, which he could test out by swapping the two subs, as Keith recommended.

We are on the same page.
post #6143 of 6280
Quote:
Originally Posted by Kimwyn View Post

By swapping the subs what do you mean? Simply alternating the subs (place the one on the right on the left and vice versa)?


Yes. If the problem follows the sub, then the sub is the culprit. If the problem stays where it is, then it's not the sub and we can start looking for something else. Be sure to have the volume set the way it is now - ie if Sub 1 is the suspect sub and is at volume setting 12 and Sub 2 is set at volume setting 8, make sure when you swap them that you set Sub 1 (now Sub 2) at 8 and Sub 2 (now Sub 1) at 12.

 

I didn’t catch that your suspect sub is set at a much higher volume level than the other sub (thanks AJ). If that is the case, and they are both reading 75dB, then AJ and Jeff are probably right and the sub is sitting in a null and you are trying to increase the gain to compensate for the null, but it is pointless because the more you increase the gain the more the null 'resists' and eventually you reach a point where you either blow up the sub (extreme case) or cause it to complain in some way - eg by audibly distorting, or by bottoming.

 

But try the sub swap first - it is so easy to do and it will tell us if the problem is in the sub or the setup.

 

Then the next step would be to move them, or at least the suspect one, to a different part of the room and recalibrate and see if the problem has gone away (the Jeff & Jerry solution). You could do this even if the new location for the suspect sub is temporary and you can't leave it in the new position for WAF or whatever - at least it will get you somewhere further along the path of solving the problem. Once you know what the problem is for sure, then we can suggest ideas that may help you overcome it - but the first step has to be identifying the problem. So far, we haven't completed that essential step.

post #6144 of 6280
Thanks Keith. I definitely understand what you are saying. I will do that and report back. The gain on teh suspect sub IS higher than the other but not A LOT higher. The suspect sub is set at 12 o clock and the other at around 11 or so.
post #6145 of 6280
Quote:
Originally Posted by Kimwyn View Post

Thanks Keith. I definitely understand what you are saying. I will do that and report back. The gain on teh suspect sub IS higher than the other but not A LOT higher. The suspect sub is set at 12 o clock and the other at around 11 or so.


You're welcome. Ah - if the gain difference is only 1 notch or so, then it probably isn't all that significant - just normal room placement variations could account for that. Try the various suggestions you've received anyway and then we can take it from there.

post #6146 of 6280
The gains on the ULS 15s are NOT consistent. Run a sub test tone and put an SPL meter about an inch or so away from the driver and see that their outputs are the same.
post #6147 of 6280
Quote:
Originally Posted by wingnut4772 View Post

The gains on the ULS 15s are NOT consistent. Run a sub test tone and put an SPL meter about an inch or so away from the driver and see that their outputs are the same.

 

I think he did this already didn't he?  Said they were both outputting 75dB? Not sure of his measuring technique though, so good advice to use the SPL meter close up to the driver, for purposes of this testing.

 

(I bet your 4 subs sounds awesome BTW!).

 

In your experience with these subs, would you expect them to bottom out on any content if they are set no higher than 12 o'clock on the volume control?


Edited by kbarnes701 - 8/13/12 at 7:50am
post #6148 of 6280
Quote:
Originally Posted by kbarnes701 View Post

I think he did this already didn't he?  Said they were both outputting 75dB? Not sure of his measuring technique though, so good advice to use the SPL meter close up to the driver, for purposes of this testing.

(I bet your 4 subs sounds awesome BTW!).

Sorry if I missed that but did he mean 75db from the listening position or right at the sub. Really big difference.


They do!biggrin.gif
post #6149 of 6280
Quote:
Originally Posted by wingnut4772 View Post

Quote:
Originally Posted by kbarnes701 View Post

I think he did this already didn't he?  Said they were both outputting 75dB? Not sure of his measuring technique though, so good advice to use the SPL meter close up to the driver, for purposes of this testing.

(I bet your 4 subs sounds awesome BTW!).

Sorry if I missed that but did he mean 75db from the listening position or right at the sub. Really big difference.
 

 

I don't think he said, but I suspect it was from the MLP.  It's an interesting case and I am sure, collectively, we will be able to help with it.

 

 

Quote:
They do!biggrin.gif

 

I bet! biggrin.gif

post #6150 of 6280
Quote:
Originally Posted by wingnut4772 View Post

Sorry if I missed that but did he mean 75db from the listening position or right at the sub. Really big difference.
They do!biggrin.gif

Both subs combined for 75dB at the MLP. and i gain matched them (or at least i think i did to my knowledge) before proceeding with anything.
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