Compatibility of JBL Woofers and Amplifier

[umar.ghauri176]

Hello everyone.
I hope someone can answer my question regarding the amplifier to use with 2 JBL woofers. Im really confused guys.
Actually last week for my room, I`ve purchased 2 12" JBL GT5 S12 woofers and installed it in the box.
Each woofer has these specs:
Impedance: 4ohms
peak power: 1200 watts
RMS power: 300watts.
Single voice coil

Currently i have kenwood amp DG-9. And when i check amp speaker terminals, there it is written 6~16 ohms. my questions is that can i run these woofers on that amp.
I mean woofers are of 4 ohms. and amp range is 6 to 16 ohms.
Does it burn out my amp or speakers ?.

Please advice guys.

Or if this amp is not compatible, so which brand do you suggest ?

 

[americanaudiophile]

If you tried it with your amp it would either blow a fuse in the amp, go into protection, or blow up.
You are going to need an amp stable to 2 ohms to drive those woofers in parallel.
If you hooked them in series you could use the DG-9 since that would be 8 ohms.
When you connect woofers in series you reduce the damping factor of the amp so the bass isn't as controlled.

 

[umar.ghauri176]

Thanks American audiophile for the reply, Also I want to ask you one thing more that ok right I agree with you to connect the 2 woofers in series circuit so that the 2 each 4 ohms woofers will become 8 ohms for DG-09 amplifier within the ohms range of 6 to 16ohms.

My question is that is it Ok for the DG-09 amp to handle the woofer power of 1200 watts each means total of 2400 watts peak power of both woofers. and total of 600 rms power. Because in series circuit we connect 2 woofers in one speaker terminal.

 

[americanaudiophile]

Can't find specs on that amp online.
If the amp won't put out 600 watts rms into 8 ohms it will limit the maximum volume that they can play.

 

[umar.ghauri176]

Hi American Audio Phile
Actually after browsing the net I`ve found this link,
https://page.auctions.yahoo.co.jp/jp/auction/l407844358
actually this is the kenwood amplifier DG-07, and its pretty much similar to the DG-09.

Also at the back of my DG-09 amp it is written
AC 100 V
50/60Hz
135 watts.

 

[americanaudiophile]

The 135 watts is the maximum wattage the amp will draw from the wall outlet not the amp power output.
Probably 30-50 watts per channel. Not much for those woofers especially if the box is sealed and small.
You may need to get a much more powerful amp.

 

[umar.ghauri176]

hmm you are right. I agree with you.
1 channel cant hold that much power of 2 woofers of 2400 watts PMPO, and 600 RMS.

So can you kindly suggest me which brand can i go for amplifier. ?
Actually im from Asia region, here i searched for amplifiers of 4 ohms range but bad luck cant find the amp which matches with these JBLs.

Here some people suggest me to use car amp with these woofers.
but which brand do you suggest.
Also i have confusion car amp runs on 12volts, then how amp handles that much power of 2400 watts.

And for purchasing power supply that converts 220 volts into 12 volts, which things can i keep in mind so that car amp will not get effected. As here we have 220 volts in wall outlets.

 

[americanaudiophile]

If you can find a 600w at 2 ohm subwoofer plate amp I would suggest that instead of using car amps.
If you get a car amp you want one that can produce the same amount of power. Wire the speakers in parallel to get 2 ohms. Don't worry about the peak power rating as that isn't going to be accurate in most cases.
Car amps are usually digital so they are very efficient at converting the 12vdc into audio power. You will need a power supply that can product the maximum current draw of the amp. Probably about 50-60a. The fact that you have 220vac is good as that provides more power at less current to the power supply.
You can use a PC power supply.
http://www.instructables.com/id/Car-Amplifier-and-Subwoofer-Powered-By-a-Computer-/

 

[umar.ghauri176]

Hi Americanaudiophile,
how are you. sorry to disturb you again.
Want to confirm one more thing about the amp.
From last few days here, Im searching a lot about amp in the market with range of 2ohms but still no luck.
In each and every shop, there are amps with 6-16 ohms of Tech, Denon, Sony etc.

Then I`ve found couple of shops who have the amp of ONKYO, and at back of the terminals its showing 4~16 ohms.
I`ve found the image links on net of that amp.
http://www.suwa-koubou.jp/repair/fr_v5/large/fr_v5_01.jpg >>>>>>>> Front view
http://www.suwa-koubou.jp/repair/fr_v5/large/fr_v5_02.jpg >>>>>>>> Rear view

so can i use that one for my JBL woofers.? If ohms are matched so is there possibility to use this onkyo one.
also the shopkeeper said that it runs on 110 volts as showing at back of the amp. for this he said to use converter for 220 to 110 conversion.

 

[americanaudiophile]

The small Onkyo you link to isn't remotely going to play those woofers. Just not powerful enough to drive them very loud at all.
You would need a stereo amp (not a receiver) with at least 100 to 300 watts x2 into 4 ohms. A car amp and AC to DC power supply might be your cheapest option. Some people use PC power supplies with minor modification that you can find online.

 

[umar.ghauri176]

Hi Americanaudiophile,

Hmm you are right the Onkyo amp is also small in size.
also it is 4 ohms, but cant handle the 600 watts power.

Anyways as im not find any home stereo amp with 2 ohms or even with 4ohms, so I decided to go with car amp. For car amp some of the amp shopkeepers suggest to use these 2 woofers with 4 channels car amp.
Means he said to me that it would be better to have 4 channel bridgeable amp with these 2 woofers.
For wiring he said that he will wired like this in image below:
https://images.crutchfieldonline.com/ca/learningcenter/car/subwoofer_wiring/2SVC_4-ohm_4ch.jpg

So whats your thoughts on this can i go with the bridgeable amp, is it better to have 4 channel amp.
or the 2 channel car amp.

And which amp is better nowadays i mean, caliber, rockmars, bm classic, or nay other brand you suggest.

 

[americanaudiophile]

A bridged amp is not as stable as an unbridged amp but may be more expensive to get the same amount of power. Personally I prefer the stability.
Can't help with the brands. Not familiar with car stereo brands.

 

[umar.ghauri176]

Hello dear how are you,

Hope all is going well.

I`ve purchased 2 jbl woofers GT5-S12s, ported enclosure, with separate chambers for my home. And finally also got an amp for it.

The thing is that due to which im very confused and want your kind appreciative feedback is that the placement of the enclosure in bedroom, currently I`ve placed it like this Image in vertical position.

The thing is that while playing tracks, I`ve noticed that when I stand up, the bass lacks, where as when I sit, i hear lot of bass. Also I noticed that in vertical position of enclosure, the bottom woofer gives more bass as compared to the upper woofer, although both woofers are the same model.

Secondly when powered off, I noticed that when I hardly knock the bottom woofer cone, it gives bass sound boom boom, and when i knock the upper woofer, it gives not that much bass sound like the bottom one.

For placement some people say that place the woofers face towards the wall, but with some space between wall and the woofers. So want your opinion on that.

Please help.