[shooga]

I just installed an SVT Sub/Amp into my 2005 ZX3 and everything went really smoothly. Only problem is that I'm not getting nearly the level out of the sub that I think I should. I know it's just the factory sub, but I think it should be able to do better than this...

I know that the factory amp has a balanced input. Ford uses this to send the signal long distances without having to worry about noise being induced. I hooked up my Alpine subwoofer output (RCA +) to one of the two signal input wires on the factory sub connector. I think the problem is that a balanced input has a summing stage where the two signals are combined back together (and noise eliminated) - but now the summing stage is only getting one input and therefore the signal is at a lower level than it should be. The amp then doesn't have the gain to give me the power that I want.

I have the subwoofer output level on the Alpine turned up all the way, but there's not the really noticable difference I would expect when adding a subwoofer.

Has anyone else run into this problem when using the factory sub with an aftermarket head unit? Any solutions?

I'm considering my options: unbalanced to balanced converter, aftermarket amp, etc. My headunit actually has two subwoofer outputs that I might be able to sum together to increase the signal strength, but the only passive circuits I've seen for doing this also attenuate the signal - so the problem would still be there.

Thanks.

 

[HaveBlue83]

I heard that using the stock Audiophile with an aftermarket HU causes staic a little, and it doesn't have to power it would have with stock HU, cause of the wiring and stuff.....I just put a kicker 8" in the stock box, and a kicker amp under the seat, and its GREAT......

the stock sub is paper, so you prolly aren't gonna get what you want out of it anyways in the long run.\


EDIT: my audiophile unit stock DID sound nice......it bumped nicely for stock......but not like the Kicker does []

 

[Foci_Fosho]

I also recommend dumping the stock sub and amp for better... But if that's not part of the plan right now...

Is it possible to hook up a Line Out Convertor, to the stock amp for a higher pre-out voltage.

 

[shooga]

An upgrade might be in the cards long term, but I'd like to see what I can get out of the stock setup before tossing it. I know it's decent and decent might just be good enough for me.

I thought about a line output converter, but would the output of it really be higher than what my headunit is supplying?

 

[Rudel]

What does your sub sound like? I had an issue where it sounded like the settings were low, but I had them all the way up.

Turned out that the Alpine HU I have has a 2 options for your sub output power...

Go to your Sub Woofer System settings and select System 2 if you have it.
Also make sure you do not have the DEAF on, turn it off.

Hope that helps!

 

[shooga]

The sub is definitely there and doesn't sound distorted at all. When I'm stopped I can hear it and I'm definitely getting better low frequency respose. But I have to have the sub output on the Alpine cranked up all the way to really hear it - even when I'm stopped. So as soon as I start moving it's mostly masked by the road noise. It just needs a bit more gain to give me what I want.

I looked at all of the settings on my headunit and unfortunately there aren't different modes for the sub output.

I don't think I'm deaf yet...I hope not anyway, I need my ears for my job...

 

[shooga]

Alright. Don't know if anyone is following this or cares, but I decided to get a line driver from Peripheral. It will let me take my 2V output on the alpine up to 10V or anywhwere in between. Should do the trick nicely. It was $30 from CarDomain.com (link)



A note about this should probably be added to the FAQ about using the SVT sub/amp with an aftermarket head unit. Basically, if the head unit has 4V or better line-level outputs then it's probably fine. But with a 2V output you need a few more dB of gain. People should know what to expect.

It should get here next week. I'll post with the results.

 

[Rudel]

I didn't know you have a 2V output ouch! My Alpine has the 4V.

There is a FAQ on how to connect your Aftermarket HU with the SVT audio system.

http://www.focusfanatics.com/forum/showthread.php?s=&threadid=8112

It took some questions to get the input I needed to be able to get mine hooked up. Take a look at it.

 

[shooga]

Thanks for pointing that out. I did read that before doing my install, but I didn't have the factory subwoofer wiring harness in my vehicle so I really just used that thread to verify that the amp would work with an aftermarket head unit. I found wiring diagrams that showed what pins to use on the sub amp input connector by searching around the forum.

Yeah, mine is a pretty weak 2V output. 2V used to be the norm and then they started moving up from there. I guess Alpine dropped back down to 2V for this model (IVA-W200). Annoying, but hopefully this $30 part will solve my problem. Otherwise I might just build my own balanced line driver - since that's what the amp is designed to accept.

I guess I was thinking of the FAQs as a closed resource, instead of a normal thread. I'll just add the info about the amp input to the thread. I just hope people make it to the end of the thread...

 

[shooga]

Got the Peripheral Line Driver (PLD10) installed today and it does the trick. The sub level is now where it needs to be with plenty of head-room left in the sub out level control on the Alpine. It was an easy install and I'm happy with the results. It definitely doesn't hit like an aftermarket sub would, but it does pretty good.

I think a balanced line driver would be a better solution, but short of building one I haven't seen one for anywhere close to $30. So I think this is the way to go.

Anyone adding an aftermarket headunit to their audiophile setup should definitely keep this in mind.