[kedarwalke]

Hey Gurus,

I have installed a pioneer 4250 touch screen head unit in my skoda superb.I have a attached a JBL GTO601.1 mono amp with two GTO 1502D 15" DVC subwoofers.

I am not getting proper punch from the woofers.There is a lot of vibration and I am not getting that tight punch or the club kind a sound from it.

Should I stick to a single 15"sub so i get the desired effect?

Should I change the subs?should I go for a single 12" JBL GT5-1204BR sub with the enclosure.

My basic requirement is a very tight bass.

Pleas help.

[low_bass_makker]

Get damping done it will help in improving the sound a lot. And try to open something which will make the boot and the cabin one. A slot in a rear deck or handrest on the back set.

[Invinsible]

Apart from what LBM has suggested. There is other important factor that matters is the enclosure size. Wrong enclosure size could also spoil the fun. Making the sub sound tight, low, boomy all is dependent on the enclosure size and quality.
Let us know what is the outer dimension of the enclosure, just to be certain about it. Possible a pic would also help.

[panky12345]

JBL 601.1 is a very powerful amp..how have you wired the pair of DVC subs?? you may also like to check if your subs are "in-phase", try reversing the phase and see if the bass improves. and as invinsible righly pointed out, this could be attributed to wrong enclosure as well.

[Epic]

I hope I am asking the right question here. How have you managed to connect TWO DVC subs to a single channel (monoblock) amp?? Is this even possible or am I missing something here? Should'nt you have two seperate monoblocks since you have two subs?

[Invinsible]

Originally Posted by Epic

I hope I am asking the right question here. How have you managed to connect TWO DVC subs to a single channel (monoblock) amp?? Is this even possible or am I missing something here? Should'nt you have two seperate monoblocks since you have two subs?

Two DVC subs can be wired in series and than parallel but the impedence remains the same. i.e. If the 2 subs are 4ohm DVC than you could have them running in 4ohms or 1ohms.

here is the example http://a248.e.akamai.net/pix.crutchf...4-ohm_mono.jpg

[panky12345]

Originally Posted by Epic

I hope I am asking the right question here. How have you managed to connect TWO DVC subs to a single channel (monoblock) amp?? Is this even possible or am I missing something here? Should'nt you have two seperate monoblocks since you have two subs?

the best power would be extracted only if the 2 dvc subs in question are 2 X 2ohms.. which would present a 2 ohm load.

but if he's using 2 X 4ohms, then the final result is either 1 ohm (which is wrong since the amp is stable only @ 2 ohms) or 4 ohms (the amp is not extracting the best).

[kedarwalke]

Originally Posted by low_bass_makker

Get damping done it will help in improving the sound a lot. And try to open something which will make the boot and the cabin one. A slot in a rear deck or handrest on the back set.

I tried keeping the arm rest open but no impovements.will get the damping done asap.

Originally Posted by Invinsible

Apart from what LBM has suggested. There is other important factor that matters is the enclosure size. Wrong enclosure size could also spoil the fun. Making the sub sound tight, low, boomy all is dependent on the enclosure size and quality.
Let us know what is the outer dimension of the enclosure, just to be certain about it. Possible a pic would also help.

The mdf enclosure size is 33"Lx 12.80"depth and 16.14"Ht.Although there is air leak from the enclosure.Can you please reco
mmend the proper size box?I ve attached the pic of the enclosure.Well wiring has been done as per your attached link.

Originally Posted by panky12345

JBL 601.1 is a very powerful amp..how have you wired the pair of DVC subs?? you may also like to check if your subs are "in-phase", try reversing the phase and see if the bass improves. and as invinsible righly pointed out, this could be attributed to wrong enclosure as well.

Tried but not much difference.

Originally Posted by Epic

I hope I am asking the right question here. How have you managed to connect TWO DVC subs to a single channel (monoblock) amp?? Is this even possible or am I missing something here? Should'nt you have two seperate monoblocks since you have two subs?

I ve done the wiring as invinsible has attched the pic,not sure whether the 601.1 is capable of handling bot the 15" subs.But currently they are doing a good job with the original JBL wiring.my only requirement is a tighter punch.

Originally Posted by panky12345

the best power would be extracted only if the 2 dvc subs in question are 2 X 2ohms.. which would present a 2 ohm load.

but if he's using 2 X 4ohms, then the final result is either 1 ohm (which is wrong since the amp is stable only @ 2 ohms) or 4 ohms (the amp is not extracting the best).

I am not sure about the ohms!should I stick to just one single 15" sub with the proper enclousre to get the tight punch?
Or should I go for a [COLOR=#0066cc]JBL GT5-1204BR or Infinity Ref1240SE [/COLOR]

[kedarwalke]

Sorry forgot to attach pic of the enclosure;

[NOTORIOUS]

it's a desi enclosure , change it asap.

[kedarwalke]

Originally Posted by NOTORIOUS

it's a desi enclosure , change it asap.

I know!!Got it done form the local chotu,ustaad,raju types!!!this box was done 4 years back when I had them in my scorpio.From where do I get the enclosure done?

[navin]

Frank has used Sanen and Invinsible knows someone in the subrubs (Irla I think). Where are you located in Mumbai. I'd suggest getting one done by someone in your neighbourhood.

[Invinsible]

Originally Posted by kedarwalke

The mdf enclosure size is 33"Lx 12.80"depth and 16.14"Ht.Although there is air leak from the enclosure.Can you please reco
mmend the proper size box?I ve attached the pic of the enclosure.Well wiring has been done as per your attached link.


[COLOR=#0066cc]JBL GT5-1204BR or Infinity Ref1240SE [/COLOR]

Firstly the Enclosure size looks fine if the above mentioned spec is the outer dimension. The internal volume comes to about 2.96cu.ft which is close to what it requires. I would suggest you check if the enclosure is sealed tight.
The mismatch here is the sub and the amp. The amp delivers around 580RMS at 2 ohm where the sub you have wired delivers 4ohms. Which is around 425RMS as per the manual. There would be not much audible difference between 425 and 600RMS. Just around a 1db.
The issue I see is
1. Enclosure having leaks is bad and if its not well damped. Try getting a better constructed enclosure or try sealing all the internal joints with a silicone and lay some acoustical foam of .5" to .75" around the internal walls. Also, make sure the enclosure had a baffle in between separating the two chambers for the subs.
2. the break in period makes a difference. Most subs require some 30-40hrs of playing time to completely break in to hear the actual result.
Intitially you may not find that the sub is playing low and tight but as the sub will start breaking in you would hear the difference.
3. Having single sub or dual doesn't make difference to the sound characteristic. What makes difference is the construction of the enclosure and the volume of it. Having dual setup means more surface area to push much more air in the boot area, which means the efficiency of the sub under dual setup is higher compared to a single setup. That is good.
4. Check if the gains are set right. Setting the gain higher would send clipped signal to the sub which sometimes makes them sound distorted and with the panels vibrating could make one feel the sub is not upto the mark.

How long it's been you had the sub ? try playing them more for sometime. In the end if you still not get the desired result I would look for getting better quality enclosure and if yet not than the sub, may be Infinity ref1260. But, looking at the specs, the sub seems quite good enough.

[kedarwalke]

Hey Invisible and Navin thanks for the valuable inputs!
The enclosure box is around 3yrs and is not upto the mark.
Initially i will change the enclosure and wait for the results.
So according to me the main culprit is the enclosure.I put up in Andheri,if you guys can tell me from whom and where can i get a good enclosure.
Also i have not got the boot damped,can someone provide me as to where I can get the damping done as well??

Thanks in advance!!!

[Invinsible]

Originally Posted by kedarwalke

Hey Invisible and Navin thanks for the valuable inputs!
The enclosure box is around 3yrs and is not upto the mark.
Initially i will change the enclosure and wait for the results.
So according to me the main culprit is the enclosure.I put up in Andheri,if you guys can tell me from whom and where can i get a good enclosure.
Also i have not got the boot damped,can someone provide me as to where I can get the damping done as well??

Thanks in advance!!!

THere is this person designing enclosure at Irla lane. PM me if you need more details. ALso, the size can be re-worked.
Or you could also get in touch with Ramie or B&T for damping and others.