Need Help :: SVS PB-1000 Poor Bass Response

[slash1814]

Hi Folks,

Got the SVS PB1000 today, it has replaced a Polk-PSW110. I am not getting the desired output (bass) from PB_1000. The following are settings made on Sub.
-Volume 50% (12'0 clock)
-Phase = Zero
-Low Pass Filter = LFE

To get the desired output I have to set AVR (Subwoofer) volume to Max i.e. +12 Db.

Is it the placement (see the attached pic.). Its the right corner (same where Polk was placed). The front port is 7 inches away from Sofa.

Please suggest.
Regards, Slash.

 

[Arjun4]

Please refer the sub woofer section on the below link. I had the same issue initially. I ran Audyssey again and moved the volume from 12' O clock to 1.

BATPIG'S DENON-TO-ENGLISH DICTIONARY

 

[Appys]

Yes, rerun audyssey /ypao and then instead of bumping subwoofer volume use the avr to raise the o/p to the sub.. I had a pretty similar experience with my yamaha just two days ago. Ypao and avr bump with a proper crossover sorted out for me.. Also try to squeeze 1ft distance between sub and walls on either side, may work better

 

[slash1814]

Subwoofer can not be moved, unfortunately. I do not use Audyssey, prefer manual setting only. However, I shall try running audyssey and see what happens.

 

[efernand1]

Hi Slash,

Congrats on the sub!

What you need to do is run the for sometime well as the cone (speaker) needs to open up...(burn out) for optimal performance...this is true for any speaker....

Dont change the position, i am sure the AVR you are using has Bass settings, Crossover settings....keep tweaking with the same to ensure the appropriate signals go to the sub....i am sure you will find the optimal sound (sweet spot).

On the AVR..keep the sub levels somewhere around 60%....on teh sub a little more than 50% as the sub is new and is yet to blend in.....

All the best...

 

[Hari Iyer]

Low bass is due to phase mis-match between the subwoofer and the front speakers. You can try this if you have a variable phase control. You will require 2 person to do this. One to adjust the phase control and other to listen to the minimum bass point.

1. Reverse connect the polarity of either the front speakers or the subwoofer(if possible).

2. Play music which has sufficient bass and adjust the variable phase control in the sub to get a minimum bass at one position of the phase control. The minimum bass is the complete out of phase position. Leave the phase control as it is.

3. Go ahead and connect the speakers (front or sub) with the correct polarity. This will ensure perfect phase match between the sub and the fronts.

Do let all of us know the result.

 

[Fantastic]

The variable level control on your sub is to enable it to match with any system ( whose signal level is not known and often doesn't follow a standard ). So when you don't know anything and have no measuring apparatus you can set it at maximum and control the level at the amp. If you find it too high even with the lowest setting on the amp then reduce it by say a 20 degree rotation on the sub and re adjust the level on the amp and check again. Repeat till you get a acceptable level.
To know if the sub is out of phase set the phase control ( variable I guess ) at zero or max ( 180 degrees) and compare the two. Finding an in between point on the rotary control will be very hard as the phase mentioned there is only applicable at some frequency and not the whole band.
Unless you are quite expert at this , the best adjustment is done by using a measurement mic. But you can get by without measurement as you may like it better when you set it manually to your own 'taste' !

 

[slash1814]

Thanks for your responses. Let me check and revert.
Just to reassure "Port is 7 inches away from one side of the sofa" Is it not hindering the port? Please refer to the picture in my first post.

 

[ttarasu]

Hi,all
Me too experience the same problem ,my settings are as follows
Denon Avr x3100,velodyne impact 12
Placement -left corner
Avr setting-120
Woofer-to maximum (to right end)
Volume-at 50(12oclock)
Used audyssey,front spks-Dali zensor 3
Room-13.5/10.5 with two windows(covered with heavy cotton curtains)
Problem -muddy,not getting the old setting when used this same sub with Onkyo
Thanks for your all suggestions

 

[slash1814]

Problem -muddy,not getting the old setting when used this same sub with Onkyo

You mean it can be an AVR issue? (Denon in your case)..Can AVRs vary this much in their settings for SW.

I had used Yamaha RX-471 earlier with same Polk-110, when I switched to Denon X-1000, I never found any issues as far as Polk was concerned.

 

[Murlidher]

I had different SW experience by moving few inches here & there.. you may have to work this way, by running audyssey again & again. I finally got the desired location. but had to increase my receiver sw db level to from -9 to -5

 

[ttarasu]

If we move few inches of the sub,does it need fresh audyssey

 

[slash1814]

Here is the picture to have better view of Front / Center Speakers with respect to Subwoofer..extreme right corner. I think They are pretty much inline and the phase issue might not be there. BTW I have tried both values i.e. 0 and 180 phases. No significant difference. I am not an Audyssey fan, but i'll give it a try with this new Sub.
As per my earlier exp. with Audyssey, it sets SW vol and other speakers Vol in negative, despite many trials and following all Audyssey rituals.

 

[machinfinity]

Sub seems to be kept in a difficult position. Moving it out will help. Audyssey rolls off bass frequencies below 27hz so there's no use for it.

 

[slash1814]

If I move out the sub, it (and its port) will almost hit the sofa (which can not be moved).

 

[rayvonnee]

Which cable are you using to connect avr to subwoofer? I doubt it should make a difference considering you must be using good ones. Try moving your sub out only as a temporary experiment so that you will know whats the problem exactly. My uncle faced similar issue when he upgraded his harman kardon avr with a marantz. However no solution for this as of yet. Try turning off audessy and follow some simple steps which you can simply google. Also as mentioned let the sub break in properly, my polk psw110 too required some break in time to sound good

 

[Murlidher]

There is so much discussion on why audyssey sets sub negative. Audyssey is still good, people however move up to 4 to 5 dbs than what audyssey sets

 

[Murlidher]

Also you should not keep the db above 0 as it would run the sub hot which is generally not a good practice

 

[slash1814]

I have made a couple of adjustments.

1) The Sub. Volume is between 1 & 2 o' clock (see pic. below)
2) I have to keep AVR vol. +3 DB for movies (However for music I must go upto +8)

Let it break-in for sometime. We'll see. I'll keep you posted.

 

[Hari Iyer]

Phase mismatch between front and sub is the only reason for low bass. Period. You need to adjust phase meticulously as instructed. The correct phase could actually be between 0 deg and 180 deg and not necessarily at 0 deg or 180 deg.