Not Another Sub/Amp Thread...

Greetings. New Golf TDI owner here. Been lurking for awhile learning a ton, figured it's time to come out of the shadows. I'm getting ready for a sub-install (yes, been through a ton of threads), but I've got a few questions on my mind:

I'm going to be doing a typical install: Uber-Stealth under-floor box with a single channel amp in the hatch and a flush-mounted gain knob in the panel. I'm still debating between the Rockford PBR300X1 and one of the similar level JLs (250 or 300). Both the amps have high-level inputs, yet people are still putting in line-out converters. Is this just because it's better quality than doing it in-amp?

Also, both these amps have auto-on functions, yet people are still running remote lines. Why? Just for extra assurance?

And last question. I'm leaning towards the Rockford, but the remote knob is labeled as an EQ as opposed to just gain like the JL. I don't quite understand how EQ would work on a sub, will it just function as gain? And has anybody tried doing a flush mount like VeeDoubleme did with the JL (Awesome writeup BTW, thanks for that - I'm pretty much stealing your entire design . I just put in a button for my garage door in one of the center blanks this morning and I was surprised how the tiny button barely fit in without pulling out the Dremil.

Thanks for any input.

Skirball said:

I'm going to be doing a typical install: Uber-Stealth under-floor box with a single channel amp in the hatch and a flush-mounted gain knob in the panel.

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Good start.

I'm still debating between the Rockford PBR300X1 and one of the similar level JLs (250 or 300). Both the amps have high-level inputs, yet people are still putting in line-out converters. Is this just because it's better quality than doing it in-amp?

Click to expand...

I used the line level in, but then figured out that VW's head units cut/defeat bass as you turn up the volume. So as I turned it up past volume level 14 on my RNS-315, the bass stopped getting louder. I'd turn up the bass volume knob and it's be better, until I turned the head unit down, and then the bass was too loud. I put a Audio Control LC2i and it fixed the problem and sounds even better on top of it.

Also, both these amps have auto-on functions, yet people are still running remote lines. Why? Just for extra assurance?

Click to expand...

The JL XD300/1 that I used does not have auto on. The LC2i I used does have this, and it works flawlessly.

And last question. I'm leaning towards the Rockford, but the remote knob is labeled as an EQ as opposed to just gain like the JL. I don't quite understand how EQ would work on a sub, will it just function as gain? And has anybody tried doing a flush mount like VeeDoubleme did with the JL (Awesome writeup BTW, thanks for that - I'm pretty much stealing your entire design . I just put in a button for my garage door in one of the center blanks this morning and I was surprised how the tiny button barely fit in without pulling out the Dremil.

Click to expand...

Thanks.

Here is what JL says about the knob I used:

"When connected to the amplifier, the HD-RLC operates as follows. At full counterclockwise rotation, the audio will mute completely. At full clockwise rotation the level will be the same as if the HD-RLC was not connected at all. In other words, it operates strictly as a level attenuator."

Make sense? All it does it turn the sub down. So I set mine up so that it's dialed in perfectly at 3/4 of the way to max. It pretty much lives there. If I want more bass, I can over drive it by 25%, and I can turn it down as much as I want. I almost never touch it though, as the LC2i does an amazing job of keeping the sub in line with the speakers.

As for amp choice I'm sure the RF works great, and it's smaller and a little bit cheaper, but it's also only 1/2 as powerful which is a big difference. It's 300W claim is only for 1 ohm, but there are no shallow mount 1 ohm subs. If you run 2 ohms it's only 150W, whereas the JL is 300W at 2 ohms. Step up to 4 ohms and the RF is just 75 watts, whereas the JL is 200W at 4 ohms.

And yeah, there's not a lot of room behind those face plates, but as you can see the JL knob fits with some trimming of the VW plastic. I cannot speak to any other knobs.