What head unit brand/model is it? So I can take a peek at the manual online.

 

Easy to find if you Google it.

Kenwood KDC 252U

 

Wait -going back to your original post...

1. "The sub volume on my head unit doesn't actually change the sub output volume. "
It should. It may not make the subwoofer get louder (that's dependent on sub amp/speaker) but check if it makes the subwoofer get quieter.

2. "The sub rises with bass along with the speakers, not independent of itself."
If you mean to say that the subwoofer output gets louder when you adjust the "Bass Level" control on the head unit (not the "Sub-W Level" but the "Bass Level") then it sounds like you may have the
built-in crossover filters set to full/full. From what the manual shows me, your particular model of head unit has a single pair of RCA outputs in the back of the unit marked "REAR/SW" - to which i am guessing that's where you plugged the RCA to Speaker wire for the sub connection. That means:

A. If the RCA output is set to "REAR" it's meant for sending FULL frequencies to an aftermarket amplifier to power full-range rear speakers. Subwoofer level control will NOT affect the output.

B. If the RCA output is set to "SW" it's meant for sending sub/low frequencies to an aftermarket amplifier to power a subwoofer. Subwoofer level control should affect the output in this mode.

It seems like your head unit is running with the RCA outputs at the "A" option. To change this, Try going into the FUNCTION > AUDIO CTRL mode and setting "HPF" at 120HZ, then set "LPF SUB-W" at 120HZ. This should tell the head unit that you're trying to use the REAR/SW RCA outputs for a subwoofer only, not full range.

See what happens from there.

Keep in mind that swapping to an aftermarket head unit will NOT make the OEM subwoofer put out more bass; that's because you're still using the OEM sub amp. If anything, your subwoofer output will seem weak compared to when you had the OEM head unit; this is because the aftermarket head unit will be able to drive the main speakers with more power than OEM, and your main speakers mid-bass/bass might actually sound louder than sub-bass coming out of the OEM sub/OEM sub amp.

 

I already had it at SUB instead of REAR. The frequencies can only be adjusted for LPF, so I set that to 120. When that is set, it allows changes to the phase setting. It all sounds the same to me...

 

Is the subwoofer moving though when you're playing music?

 

It is. But like you said, the speakers overpower it. The settings (LPF, Phase, Sub output) don't change anything.

 

Well then it's working, but that's probably all you'll get out of it with the upgraded head unit powering the main speakers louder than before. That's the main reason why I installed an Epicenter.

 

That's my next step. Well, besides upgrading the 2 rear speakers, seeing as I'm only running with 1 rear speaker at the moment.

 

after all these views no one can comment if it worked on a nakamichi setup?

 

It doesn't work with the Nak system, the Nak setup is wired differently. Some of the speaker wire stuff might work (like the harness colors) but in the 3 years that this thread has been up, no one who actually tried got it to work with the Nak setup. Sorry

 

Added 08-12-12
INSTALL TIP: If you have an aftermarket steering wheel installed, then you have no airbag function anymore. If you're installing a double-DIN head unit you can remove the airbag ECU and the junction housing from the car to get more install clearance. The airbag ECU is on the transmission tunnel right behind the head unit location - very easy to see, as shown below:



The airbag ECU is right there, with the huge yellow warning labels. It is held down by a few 10mm(?) bolts. As for the junction housing, it's also in the photo - the big white plastic thing that sits in front of the airbag ECU, behind the ashtray, as shown below:



The junction housing is the white plastic thing shown above; the junction housing holds four electrical harness plugs and sockets. With a small flathead screwdriver and some patience you can pop all of the harness sockets out of this white plastic thing. Then remove the junction housing from the car, reconnect the electrical harness plugs (there's four, and they're color coded so there should be no problem here) and you've cleared more space for your head unit.

I originally dd this to clear room for the numerous head unit connections and wiring harnesses (audio, video, etc. so many wires) and there's also more "clear space" for air to circulate.

Please note that by messing with the airbag components YOU DO THIS AT YOUR OWN RISK!!!
... thus, if you don't know what you're doing, don't try it. Or if you do and something goes wrong, don't blame me.

 

i wonder raine if the metra harness would be the same with the two of them. if it is, then the speaker wires would be the same and that is all i would need to re-run to prevent ground noise. as long as the harness gave the radio stuff like power, ant, 12v constant, i could make my own ground and hijack the speaker wires.

 

As far as I can remember before I wrote this, everything I read regarding the Metra harness seemed to share one common comment - that the wiring scheme on the package wasn't exactly correct for the Lexus SC300; it seems to be a "generic" Toyota harness that works on many other Toyota vehicles. But like I said - that's all from what I read - I never bought the harness so I don't have any first-hand experience with it.

As for the rest, well let's see...

12v+ / Switched ACC+ / Ground: With some multimeter/test light work I'm pretty sure it would be easy to find these from the OEM Nakamichi harness.

Main Speaker Connections: I'm only assuming that the OEM speaker harness is the same between the Pioneer and Nakamichi; The Pioneer speaker wire colors seem to follow typical Toyota wire color schemes, but I'm not 100% sure... I don't even know if the Nakamichi setup uses a common-ground scheme like the Pioneer, or if the OEM speaker ohms are similar.

Subwoofer Connections: No clue how the Nakamichi sub is powered and/or where the sub amp is, not to mention the wiring scheme for it.

Antenna Connections: My guess would be that the antennas are the same between Pioneer/Nakamichi systems.

 

Oh snap you already know if this...... Did you figure the problem yet?

 

Just putting my 2 cents in, but I have a nak in my sc and used the metro harness and it worked, ordered it off amazon. Maybe I got lucky idk but the only thing that does not work is the stock sub****
I wired an aftermarket sub/amp