My GR SW-12-04 + A370PEQ Amp based Servo Sub Build

[naren2512]

Hey Captain,

Sorry brother for not replying for so long, I was trying to refrain myself from commenting on the subs performance.. the reason being i was not finding it to be very good.

The issues were, the sub was vibrating a little bit even after doubling all sides, and this vibration was passing to the floor.

Secondly the bass wasn't as much and as efficient ( tight ) as i expected after spending around 40-45K for total build.

So what i did is i have used a rubber mat on which i have kept the sub this stopped the vibrations to spread on the floor, now the sub does vibrate a little bit but not as much as before and it is not spreading to floor at all.

I kept listening to the sub for a few weeks but i get only a few hours each week end, and last week i took out around 40% of polly fill this improved the sub's performance a little bit.

I am using single RCA cable that i had got withy Sony Corder so not sure if changing wire to something like DAC sub woofer wire will make any difference but probably i will buy that in a couple of months or borrow some one elses wire to see what difference that makes.

To summarize I did not like the initial performance of the sub but it has improved now but i am expecting a bit more even from what it is sounding now.. so i will wait to hear from others how they are finding their subs and take their suggestions to make further changes etc .

How is your build coming up?

Regards,
Naren

Hey Naren2512,

It's been a while since your last post. Looking forward to latest developments.

 

[captrajesh]

the sub was vibrating a little bit even after doubling all sides, and this vibration was passing to the floor.

To address vibrations of the cabinet which are caused by the backward motion of the woofer cone, the cabinet needs to be damped adequately. IMO the damping provided by you may not be adequate. Also, the standing waves need to be absorbed by using materials such as fibreglass which is by far the most efficient in doing the job. Of course I', talking theory here and you are a better judge. May be Danny can help you out with some better suggestion.

the bass wasn't as much and as efficient (tight) as i expected after spending around 40-45K for total build.

I kept listening to the sub for a few weeks but i get only a few hours each week end, and last week i took out around 40% of polly fill this improved the sub's performance a little bit.

I'm not sure how much poly fill did you use and how much of it is required. Hope Danny comes up with his recommendation. May be you can fiddle with the settings to get it right.

How is your build coming up?

Just lying in the boxes on my attic.

 

[sbg]

naren2512 / Capt,
Thanks for you input.
would you all suggest/recommend the Sandbox method would be a better way control the vibrations?

 

[naren2512]

naren2512 / Capt,
Thanks for you input.
would you all suggest/recommend the Sandbox method would be a better way control the vibrations?

Yes, and it wont be so heavy so that u cant move it at all at sm time i will also convert mine to a sand boxed one

 

[Flash]

Secondly the bass wasn't as much and as efficient ( tight ) as i expected after spending around 40-45K for total build.

Regards,
Naren

Naren sometimes bass output as well as tightness is directly correlated to room placement.

Please try the Subwoofer crawl to find the optimal position for the subwoofer.

Proper placement of the subwoofer, in my opinion is probably the most important aspect of integrating a subwoofer in a room.

Also call a friend home and have him toggle the phase switch with you sitting in your listening chair.
Low output could also be a direct result of your subwoofer being out of phase with the rest of your speakers.

 

[Danny Richie]

Naren, are there pics of your box showing how it was built?

Also, please check your connections to make sure that it is plugged in properly. Make sure that you connected the thicker wires to the driver coil and the thinner wires tot he servo coil.

If those connections are reversed then the bass will be very sloppy and loose.

And to stabilize a a sub you don't want to de-couple or separate it from the floor. You want to couple it or anchor it to the floor. The best way is to use floor spikes.

You don't want the bottom of the cabinet to be sitting flat on the floor. That will allow the floor to amplify any cabinet resonance. If it is built well though, it shouldn't have much panel resonance.

 

[naren2512]

Naren, are there pics of your box showing how it was built?

Also, please check your connections to make sure that it is plugged in properly. Make sure that you connected the thicker wires to the driver coil and the thinner wires tot he servo coil.

If those connections are reversed then the bass will be very sloppy and loose.

And to stabilize a a sub you don't want to de-couple or separate it from the floor. You want to couple it or anchor it to the floor. The best way is to use floor spikes.

You don't want the bottom of the cabinet to be sitting flat on the floor. That will allow the floor to amplify any cabinet resonance. If it is built well though, it shouldn't have much panel resonance.

Hi Denny,

Thanks for your post, The pics are exactly how the cabinet is built, I think i have connected the wires correctly as well since i had asked you already on email and did connected the wires accordingly however i will double check the same.

Also I have not decoupled the sub cabinet from the floor only thing i have done is i have kept a rubber mat on the floor and kept the sub on that mat.

I will surely double check on wires. Also i will try to reduce the recron stuffing further and see if that helps.

Do you think if this could also be due to me using usual single RCA cable ( which i had got with my cam corder? ) how much role does the cable have to play for the sub's performance? if significant then i think i should first try to change the cable to something actually meant for sub woofers.

Regards,
Naren

 

[naren2512]

Thanks Flash,

I will try to do that once i get bigger wire.. as of know my limitation is the wire i have :sad:

Regards,
Naren

Naren sometimes bass output as well as tightness is directly correlated to room placement.

Please try the Subwoofer crawl to find the optimal position for the subwoofer.

Proper placement of the subwoofer, in my opinion is probably the most important aspect of integrating a subwoofer in a room.

Also call a friend home and have him toggle the phase switch with you sitting in your listening chair.
Low output could also be a direct result of your subwoofer being out of phase with the rest of your speakers.