kj4976

I just got my subwoofer installed and it is not producing as much bass as it should. I elected not to replace the factory head unit. The factory head unit varies the bass level with the volume, so at low volume there is way too much bass, and at high volume I am not getting what I paid for. My installer told me the factory unit filters the bass and it will only play out of the stock subwoofer output. Because Lexus did not design the car to have an aftermarket subwoofer, the power was limited to keep from blowing the stock sub at full volume. I was wondering if anyone else has had these issues and/or knows how to resolve them. Thanks

UHEARDME

I am not an expert, however I think he may have tapped in after the OEM amplifier (on its output side) rather than it's input side. I am assuming the amp also has equalization, so the input to your aftermarket sub amp is a "filtered" input. I will let the experts here confirm, deny or expand on this.

mlee21

look for a guy named cmusic on the forums, he knows ALOT about the 2is system.

SParker1tx

Try This:

http://www.is350forums.com/index.php?showtopic=227

cmusic

kj4976,

Your installer is correct. The 2IS's audio system filters out everything below 30 Hz going to the sub and 50 Hz going to the door woofers. I assume your installer hooked the aftermarket sub and amp to the factory subwoofer wires. In addition the bass control is centered at about 100Hz, making the bass sound boomy. In addition the ASL (Automatic Sound Levelizer) boosts the bass and treble at lower volumes and cuts it down at higher volumes.

There are some possible solutions to make the bass sound better. First is to turn off the ASL and keep the bass level at 0 or lower.

Then if your aftermarket sub amp has a bass boost equalizer circuit, turn the bass frequency as low as possible (preferably under 30 Hz) and boost the eq 3-6 dB or more. If the aftermarket amp has a crossover, set the crossover to low pass 50 Hz and down (since the factory door woofers will be playing 50 Hz and up).

Hope this helps.

kj4976

Thanks for your response to my post it was very helpful. Do you have any suggestions as to how I can get the full bass out of what I have? From my understanding I have to somehow put the pieces created by the factory head unit together to get the orginal bass signal to my aftermarket headunit. My installer said that a cleansweep would not fix this problem because the headunit would already have filtered out the bass to the stock sub. Are there any products that I can add to get my system to perform the way it would if it were hooked up to an aftermarket headunit?

cmusic

With the 30 Hz filter you can't get full range bass out of the 2IS system. If you have a non-ML system there are signal level wires (simular to RCA cables) between the head unit and the amp that can be tapped into to get a full range signal, but then the volume, tone controls, balance, and fader won't work because those functions are done in the amp.

The only thing you can do is to use an eq with 20, 25, and 30 Hz bands and boost them up atleast 3 to 6 dB or more and turn the aftermaket amp gain up. The 30 Hz filter in the factory system still lets a little bit of the sub-30 Hz music bleed through. The eq will boost those slightly bled through sounds somewhat, but it will never equal the bass performance of an aftermarket headunit.

kj4976

I just talked to my installer after he spoke with the people at JL Audio. What he told me is that they have a product the are introducing at CES that will help all 2IS drivers w/ subwoofers. Basically the product is functionally the same as a cleansweep however it is specifically designed for subwoofer applications only. As a result the price will be less than the clean sweep by a considerable amount. The person at JL said that this product will be put in production sometime in Jan 07 and should be ready by April or May to purchase at your local dealer. Sounds like a may get the chance to test this product early and If I do ill keep you guys posted.