I have a 98 LS400 with navigation touch screen (it is not Nakamichi though). I installed an Infinity Basslink in my trunk using the stock sub speaker level wires into the Infinity amp and then ran my own power wire from the battery. My question is this...when the volume is relatively low, say around the 9 o'clock position, it sounds great but as I turn up the volume more the bass gets less and less. When I hit the 12 o'clock position it doesn't even sound like I have a sub. I've checked the amp settings and gain multiple times and they all appear fine. Did Lexus have a bass limiter to the stock sub as the volume increased or something?

 

There is no bass limiter. Its possible youre clipping the amp in your basslink. Check and recheck the polarity on your line level connections.

 

Also double check that your power/remote wires are in the correct spot. I suck at life for dong that once before. Now it's a running joke.

 

I know I'm not clipping the amp, the gain has been checked multiple times. I also know that the polarity is good, plus the amp has a 180 phase switch and I've tried hitting that. Finally, I am using the speaker level inputs because they can turn on the amp and you eliminate the need for the remote wire. I would like to somehow mount it so it is using the stock location but do not really see a possible way to do that. Maybe I'll use the amp out of it and try to find a good 8" that will work free air to put in the stock location. I bet part of the problem with this Basslink is the Lexus trunk is so tight and sealed that the only sound that is coming through into the main cabin is through the stock 8" sub hole (there's a gas tank right behind the back seat).

 

Of all the years I've been doing my own personal installs and installs for others, I've never done this before. I always use a dedicated remote wire. Whether its to the HU, an add-a-fuse in the fuse box, or even as low as a toggle switch. A speaker level input wire doesn't seem to be a proper route in this case. Maybe if you were dealing with a stock unit in an old Honda or something like that, you'd be ok. Just my .02. Maybe it would be worth a shot to run a jumper remote wire and see if that works.

 

Let's also tango with ohms law. I finally secured a radio that doesn't have the RCA's hacked off. I ran a power, ground, and remote wire to an aftermarket amp. Ran a +/- from the factory sub. When I turned it on, the amp went straight to protection. I relieved the gains/levels a little and it cleared up. Stock sub sounds great. Went to turn the volume up, and the sub delivered a loud, obnoxious bass note. I set all gains and levels to the lowest setting. Turned it up and it sounded great, for about 5 seconds. At this point I'm confused and pissed. I take a look into the trunk at the magnet of the stock sub, "5 ohm". That doesn't sit well when wiring in 2 or 4 ohm configurations per the amplifier. So my final solution is replace the sub, too.

To make a long story longer, I'm wondering if your stock system is setup in a similar manner. If so, the signal coming from your factory unit (be it some odd resistance), may be hindering the outcome of response. I had a similar issue with my Infiniti.

Good luck.

 

This is the way almost all amps are that can accept the speaker level input. The speaker level has engough voltage/current to trigger the amp on.

 

I know that, I was just saying that I've never personally done it that way.

You made anymore headway?

 

Nope, it sounds great at lower volume but as soon as I hit the 10 o'clock position + the bass goes away.

I'm tempted to just get an Image Dynamics ID10, cut my stock hole larger in the rear deck and try that as an IB/free air set-up using the basslink's 200W RMS amp. Not sure though, $150+ is a lot of money for me to "try" something out

 

dang that blows

 

I've experience the same fade as you have. Additionaly the OEM sub output only goes below 60Hz.

I wish I could replace the OEM amp and keep the OEM HU happy.

 

wouldnt the wire cables melt cause it will have to power your sub?

 

Wait, what are you talking about?

Anyway, I have noticed that past a certain point my sub volume is no longer linear. Mid/high volume will increase but the bass doesnt seem to do so. I am using an LOC to an audiopipe 1800d with 2 12in alpine type r's. Stock nakamichi system in a ucf20. I will eventually replace the stock headunit with a double din and run a matching 4 channel. We will see if this behavior changes or if its a matter of the acoustics of the car itself.

 

Darn; I was thinking of doing this same kind of setup in my new-to-me 08 ES350. The non-linearity must be to not overwhelm the poor free-air sub at higher volumes... a protection of sort.

The only thing I do wonder - I get a good bit of movement out of the door speakers on bass notes too; I wonder if running a tap off of those would get me anywhere? I'm really not interested in messing around with putting in a new head unit in this car; my last car was all tricked out with a HU, amps and dual JL subs. I don't find myself needing that now; but I do want some more bass out of the stock setup.

 

I know this is an old thread, but in case anyone is lookin up info on the basslink, I wanted give my experience.

I have a basslink installed in my Tacoma, it does taper the bass output if you play it really loud. I think its the internal system to prevent damage when the amp starts clippin. For about $200 and 200w you get what you pay for. In my truck it works pretty good since its behind the drivers seat, but if you put it in the trunk of your car its probably not loud enough. If you want somethin cheap to add on for a truck, minivan, or suv and don't need a somethin really loud the basslink would probably work great.

In my GS350, I just installed a small enclosure sealed box, BA 12" sub, and a BA 500w mono amp. This puts out what I need in my car.