Go Back   Team-BHP > Under the Hood > In-Car Entertainment


Reply
 
Thread Tools Search this Thread
Old 26th August 2009, 18:26   #1
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Post 4 ohm DVC sub and JBL 1004

Hi Gurus,

I would like to get your opinion regarding the best way to fire a 4ohm DVC sub from a 1004.

I am using 2 channels of the amp to fire the compos and other 2 channels for the sub. As you know 1004 produces 100RMS at 4ohm, 150RMS at 2ohm and around 320Wrms in bridged mode at 4ohm. My sub is 600Wrms and 1400W peak.

The available options for me are,

1. connect only 1 VC and short the other to provde 4ohm load to the amp.

2. drive each coils from the seperate output terminals of the amp. In this way the load on each output terminals wil be 4ohm and the the power will be 100Wrms. So the sub will be getting only 200Wrms.

3. Parallel the coils and make the effective impedance as 2 ohm. But I am confused whether I can connect both the output terminals of the amp to a single terminal (please advice). Or can i connect this 2ohm load in bridged mode? (amp manual recommends minimum 4ohm).

4. connect the coils in series and connect to the bridged terminals of the amp. In this way the effective impedance would be 8ohm.

5. Simple ! get a mono and use 1004 for front and rear. (please dont advice me this now, I just finished my ICEing )

suggestions awaited !!!
LionX is offline   Reply With Quote
Old 26th August 2009, 18:37   #2
BHPian
 
DjNik's Avatar
 
Join Date: Oct 2008
Location: Kolkata
Posts: 340
Thanked: Once
Default

Get a good mono for your sub.Till then then the best way to connect your sub would be to bridge two channels and connect it as in the image below.You will get approx 300wrms at 4ohms.
Attached Images
 

Last edited by DjNik : 26th August 2009 at 18:39.
DjNik is offline   Reply With Quote
Old 26th August 2009, 18:40   #3
Senior - BHPian
 
abhinav.gupta88's Avatar
 
Join Date: Sep 2007
Location: Delhi , India
Posts: 4,087
Thanked: 308 Times
Default

Practically thats the only option that is good.

Get a mono and do everything without a hassle.
abhinav.gupta88 is offline   Reply With Quote
Old 26th August 2009, 20:57   #4
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

Quote:
Originally Posted by DjNik View Post
Get a good mono for your sub.Till then then the best way to connect your sub would be to bridge two channels and connect it as in the image below.You will get approx 300wrms at 4ohms.
I have read in many forums that this type of connection can kill the sub in long run. Moreover this will change the Q of the sub woofer. My amp will produce 320W rms at 4ohm so by wiring it to a single coil might burn it.

Can anyone tell how much will be the output in bridged mode at 8ohm, is it just the half of what at 4ohm?
LionX is offline   Reply With Quote
Old 26th August 2009, 21:14   #5
BHPian
 
akbaree's Avatar
 
Join Date: Jun 2005
Location: Mumbai
Posts: 585
Thanked: 48 Times
Default

Disclaimer: I am no Guru and and my suggestions may or may not make sense...

Quote:
Originally Posted by LionX View Post
1. connect only 1 VC and short the other to provde 4ohm load to the amp.

2. drive each coils from the seperate output terminals of the amp. In this way the load on each output terminals wil be 4ohm and the the power will be 100Wrms. So the sub will be getting only 200Wrms.
In a way both these options will present the same load to the Amp. IIRC each voice coil of that Sub is rated at 2.8 ohms.

The first option will present 5.6 ohms to the bridged mode. And that should be fine because the amp is 4 ohms stable in the bridge mode. The amp will not belt 320RMS at 5.6 ohms.

When you drive each voice coil with a seperate output terminal you are pumping more than 100RMS to the voice coil because the amp produces 100RMS @4 ohms.

It depends on wiring convenience which option you want to chose.

Quote:
3. Parallel the coils and make the effective impedance as 2 ohm. But I am confused whether I can connect both the output terminals of the amp to a single terminal (please advice). Or can i connect this 2ohm load in bridged mode? (amp manual recommends minimum 4ohm).
In bridged mode that amp is rated as 4 ohms stable. So don't present 2 ohms load to the amp. It will clip and may ding out as well. It may even damage the driver.

Quote:
4. connect the coils in series and connect to the bridged terminals of the amp. In this way the effective impedance would be 8ohm.
You can do this but why would you feed the Sub so less power. When a load of 8 ohms is presented, the amp will actually pump around only 160 RMS (theoretically).

Quote:
5. Simple ! get a mono and use 1004 for front and rear. (please dont advice me this now, I just finished my ICEing )
Well wait for that Clarion HU. Tune the system. And then if you think you need more punch, going for the mono would be more enjoyable. That Sub can deliver a lot more with a good mono.

Last edited by akbaree : 26th August 2009 at 21:29.
akbaree is offline   Reply With Quote
Old 26th August 2009, 21:45   #6
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

@akbaree, thank you for your suggestions. I was about to call you .

There is a correction, the sub is not 2.8ohm per coil, its 4 ohm. 2.8ohm is the DC resistance of the coil, not the impedance.

Yes, I will wait for the 785 install before considering a mono.
LionX is offline   Reply With Quote
Old 26th August 2009, 21:52   #7
BHPian
 
DjNik's Avatar
 
Join Date: Oct 2008
Location: Kolkata
Posts: 340
Thanked: Once
Default

I am really sorry for the confusion LionX, I mistook your sub for a 2ohm DVC.Thus that image is incorrect.The correct way would be either 2 ohms or 8 ohms.The amp is not stable at 2 ohms bridged.That means the only option for you would be 8 0hms.The output at 8 ohms would be really low for the sub considering it is a 600wrms, my suggestion would be to get a mono and get the max out of your sub.Which sub is it btw?
DjNik is offline   Reply With Quote
Old 26th August 2009, 22:06   #8
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

Quote:
Originally Posted by DjNik View Post
I am really sorry for the confusion LionX, I mistook your sub for a 2ohm DVC.Thus that image is incorrect.The correct way would be either 2 ohms or 8 ohms.The amp is not stable at 2 ohms bridged.That means the only option for you would be 8 0hms.The output at 8 ohms would be really low for the sub considering it is a 600wrms, my suggestion would be to get a mono and get the max out of your sub.Which sub is it btw?
its fine DjNik. Yes I know it is not giving justice to the sub by powering it at 8ohm, that is my current setup. I forgot to mention that it is giving enough punch for my taste, actually I had to reduce the SW setting in HU. I was considering some alternate ways to get the max out of the sub using the current setup. Mono is very well there in the list of upgrades.

It is Blaupunkt Velocity V-SPL 15 in a sealed enclosure. Imagine it in the HUGE cabin space of safari, you will get a rough idea.
LionX is offline   Reply With Quote
Old 26th August 2009, 22:47   #9
BHPian
 
DjNik's Avatar
 
Join Date: Oct 2008
Location: Kolkata
Posts: 340
Thanked: Once
Default

Quote:
Originally Posted by LionX View Post
I forgot to mention that it is giving enough punch for my taste, actually I had to reduce the SW setting in HU. I was considering some alternate ways to get the max out of the sub using the current setup. Mono is very well there in the list of upgrades.
Happy to hear that the 1004 performs even at 8 ohms.
As for the mono here are some options-
Alpine-MRP-500(500@ 2 ohms)
Clarion-DPX 1851(800 @ 2 ohms)(Most VFM)
JBL-7001(700@ 2 ohms)
GZ-TA 2.500TX(500@ 2 ohms)
Infinity-1600a(600 @ 2 ohms)
Harman/Kardon CA1500(600 @ 2 ohm)(the Best out of them)
DjNik is offline   Reply With Quote
Old 26th August 2009, 23:07   #10
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

Quote:
Originally Posted by DjNik View Post
Happy to hear that the 1004 performs even at 8 ohms.
As for the mono here are some options-
Alpine-MRP-500(500@ 2 ohms)
Clarion-DPX 1851(800 @ 2 ohms)(Most VFM)
JBL-7001(700@ 2 ohms)
GZ-TA 2.500TX(500@ 2 ohms)
Infinity-1600a(600 @ 2 ohms)
Harman/Kardon CA1500(600 @ 2 ohm)(the Best out of them)
It would be very helpful for me to plan if you could mention the cost of these amps .
LionX is offline   Reply With Quote
Old 26th August 2009, 23:31   #11
Team-BHP Support
 
navin's Avatar
 
Join Date: Mar 2004
Location: mumbai
Posts: 22,509
Thanked: 3,885 Times
Default

Quote:
Originally Posted by LionX View Post
1. connect only 1 VC and short the other to provde 4ohm load to the amp.
4. connect the coils in series and connect to the bridged terminals of the amp. In this way the effective impedance would be 8ohm.
5. Simple ! get a mono and use 1004 for front and rear.
Quote:
Originally Posted by LionX View Post
I have read in many forums that this type of connection can kill the sub in long run.
It will reduce the Qts but not kill the sub. WHy would it kill the sub? Where did you read this? Many many years ago I got 6 Audio COncepts DV12 dual voice coil woofers and ran them this way (with one voice coil shorted) so as to reduce the Qts and hence Qtc in a sealed box that was a triffle small. In fact Mike Dzurko of ACI used to recommend that one could tune the Qtc of the system by inserting a 100 ohm pot in the other voice coil. Dan Wiggins had recommended the same for his Shiva woofers. You might be able to Google these references - I am too old to do this googling stuff.

Quote:
Originally Posted by LionX View Post
I forgot to mention that it is giving enough punch for my taste.
if this is the case why are you looking for more.
navin is offline   Reply With Quote
Old 26th August 2009, 23:33   #12
BHPian
 
DjNik's Avatar
 
Join Date: Oct 2008
Location: Kolkata
Posts: 340
Thanked: Once
Default

These are easily available in INDIA-
JBL-7001(20k)
GZ-TA 2.500TX(18k)
Infinity-1600a(dont remember, shld be abt 20k)
Harman/Kardon CA1500-30k
These are the retail prices,you should get a disc at most of them.
Ones that can be brought from the US-
Alpine-MRP-500( Amazon.com: Alpine MRP-M500 - Amplifier - 1-channel: Electronics )(140$)
Clarion-DPX 1851( Amazon.com: Clarion DPX1851 850 Watts Maximum Mono Amplifier: Electronics )(232$)
DjNik is offline   Reply With Quote
Old 27th August 2009, 10:11   #13
BHPian
 
shreyasma's Avatar
 
Join Date: Jan 2007
Location: Bang!
Posts: 652
Thanked: 6 Times
Default

Aha! whats going on here. Sumith, If you are happy with 8ohm resistance, its fine.

Otherwise just connect each coil to each channel of amp. As Ananth has mentioned, its worth to wait for the 785. After the TA, there will be lot of difference in the way things sound.

Listen to the setup till you bored (4-6 months) and then plan your investment in a mono. This way your wife wont pose any threats to your life

Hope this helps.

Last edited by shreyasma : 27th August 2009 at 10:13.
shreyasma is offline   Reply With Quote
Old 27th August 2009, 10:25   #14
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

@DjNik, thanx brother for the efforts. These are out of my budget as of now, but will consider when I have enough vitamin M.

@navin, yes I have done some googling about the same and its been a big debate for years. I was referring to the following link
Running one vc on a dvc sub

I need your advice on the option 3, I know that its not possible to connect the 2ohm load to the bridged output. I would like to know whether I can connect both the output terminals of the amp to a single coil of the sub (coils are connected in parallel) ??
LionX is offline   Reply With Quote
Old 27th August 2009, 10:35   #15
BHPian
 
LionX's Avatar
 
Join Date: Dec 2008
Location: Cochin / Bangalore
Posts: 511
Thanked: 547 Times
Default

Quote:
Originally Posted by shreyasma View Post
Aha! whats going on here. Sumith, If you are happy with 8ohm resistance, its fine.

Otherwise just connect each coil to each channel of amp. As Ananth has mentioned, its worth to wait for the 785. After the TA, there will be lot of difference in the way things sound.

Listen to the setup till you bored (4-6 months) and then plan your investment in a mono. This way your wife wont pose any threats to your life

Hope this helps.
Yes I am happy with 8ohm but just exploring the options shreyas.

I spent around an hour last night to explain all these fundas to wife. She knows the problem now and I am in safe side .
LionX is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Issue with JBL GTO 1004 Amp Trust_In_Thrust In-Car Entertainment 7 21st June 2014 20:20
6 ohm or 8 ohm speaker?? arjithin Gadgets, Computers & Software 12 27th November 2011 16:11
JBL 1004 vs JBL PX300.4 vs GZ TA 4.120MK2 vs Infinity 475A St. Anger In-Car Entertainment 12 13th August 2009 15:26
JBL GTO 1004 Amplifier Woes!!! EDIT - Now resolved rider60 In-Car Entertainment 10 27th July 2009 23:36
JBL 12" DVC, your opinions ? s0uljah In-Car Entertainment 33 5th May 2006 13:25


All times are GMT +5.5. The time now is 19:25.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks