Amp problem? Sub problem? I DON'T KNOW!!! Help!

[nft987]

This is my first DIY car stereo installation. I just installed Focal 165-A1 component speakers and a 10" JL Audio W1v2 8ohm sub from a Sony DSX-s300btx head unit into a Pioneer MD-6500f amp. The Focal speakers sound great in front.

The problem:

I'm getting almost no sound from the sub.

The wiring all appears to be as per the installation instructions. I'm assuming the amp is just not giving the sub enough power so I should get another amp for the sub.

Is there anything else to consider or try before I go ahead and buy another amp?

I want a JL Audio W1v2 sub. I got this one for a really good price without considering what 8-ohm versus 4-ohm could mean for system requirements. If that is the issue, what should I look for in an amp to run that sub? Any specific brand/model suggestions?

Thanks!!!

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[joom 10+ year member]

Have you checked the voice coil of the sub?

 

[Jerhemy 10+ year member]

not too familiar with that amp or sub, but an 8 ohm final load is quite high for a sub amp. You want to get an amp that puts out the desired RMS by the sub at the final wiring ohm load. (8ohms for your single sub)

 

[nft987]

JL Audio recommends 75W - 300W amp power for the 8-ohm W1v2. Is there a way that can translate to find out how much power it would need from an amp running 4ohms? Would an mono amp giving the sub about 250w or 300w at 4ohms do the job?

 

---------- Post added at 09:29 AM ---------- Previous post was at 09:28 AM ----------

 

How do I check the voice coil?

Thanks.

 

[juanmgarza26 10+ year member]

JL Audio recommends 75W - 300W amp power for the 8-ohm W1v2. Is there a way that can translate to find out how much power it would need from an amp running 4ohms? Would an mono amp giving the sub about 250w or 300w at 4ohms do the job? 

---------- Post added at 09:29 AM ---------- Previous post was at 09:28 AM ----------

 

How do I do that?

nope, well its will put out about half at 8 ohms, so cut 300 in half and you sub is getting no more than 150 watts... is your amp a mono? or a multi channel?

 

[nft987]

So, I just googled info about ohms.

It seems that when the ohms double, the effective power output of an amp is cut in half. Does that mean that this 8 ohm subwoofer I have with recommended 75w-300w of amp power needs 150w-600w from a 4ohm amp?

 

[seg_representin 10+ year member]

Did you make sure your amp is turned on when you are playing music from a cd, mp3, radio, etc.? And which of those are you trying to play it from?

 

[nft987]

Whoa. That came up while I was typing that. Funny that you answered my question before I asked it. Thanks!

With this info, the amp I have is clearly not adequate. I will probably get a mono amp. Mono is probably the way to go, right? It's just for one sub.

 

[Jerhemy 10+ year member]

THE AMP DOES NOT DICTATE THE ohm LOAD THAT IT OUTPUTS AT. IT DEPENDS ON THE ohm LOAD OF THE SUBS THAT YOU HOOK UP TO THE AMP. yOU HOOKED AN 8 OHM SUB UP TO AN AMP. THE AMP WILL OUTPUT AT 8 OHMS, not 4 ohms.

and no, the speaker is rated at 75w to 300watts rms, doesn't matter at all what ohm load it is.

edit: sry for the caps lock, at work and don't feel like retyping

 

[nft987]

The amp is definitely on. The front speakers are also running through the amp. The head unit I got is a digital media player without a CD player so it's all iPod, mp3 player, etc.

 

[nft987]

Oh! Ok. ****. Just when I thought I was figuring something out.

With that info, the amp IS giving it enough power. What do you think is the problem now?

 

[Jerhemy 10+ year member]

if you think

what kinda box is this in?

 

[seg_representin 10+ year member]

He should still be getting output from the sub. Something is hooked up wrong if nothing is coming out of the sub. Check the settings on your headunit to see if there is an option to turn the sub on/off.

 

[Jerhemy 10+ year member]

He should still be getting output from the sub. Something is hooked up wrong if nothing is coming out of the sub. Check the settings on your headunit to see if there is an option to turn the sub on/off.

ahh, I read the OP as 'almost' no sound, as in it's receiving power of some sort and playing accurately, just very quiet.

How did you set your gains OP?

 

[seg_representin 10+ year member]

ahh, I read the OP as 'almost' no sound, as in it's receiving power of some sort and playing accurately, just very quiet.

How did you set your gains OP?

Yeah I can see where you read it as that. I took it as he wasn't hearing any sound from it, probably just noise from the music from rear speakers resonating in the sub. The OP can clarify which one it is.