Does anyone know if you can turn up the gain on the amplifier in the boot that runs the subwoofer in the IS250?

The reason I'm asking is I like a little more bass in my music and with the bass turned all the way up it's still not enough on some songs, so I was aware that in some cars you can turn up the gain directly on the amp because it's usually set quite low from the factory and I was hoping someone else out there had already found out how.

I would guess that the answer is no, but pm BIGW on this forum, or do a search on the myis forums.

Thanks DR-JEKL.

The short answer. No.

Gain is not a volume control as you may or may not know. The gain is set to a level as to provide minimal clipping. If you require more low end add an aftermarket amplifier and subwoofer.

The factory amp in the IS250 is a bugger.

If your wanting to add amps to power front speakers (3 way split)

You cant even splice into the factory input signal (to give pre outs to aftermarket amps) because when you remove the plug you lose control of your in dash unit.

The only way to do it is speaker level inputs and even then thats not easy. You will require processing. As the outputs from the amp are midbass, midrange, Tweeter, & sub. When you get a signal from one of those its not a full range signal so what is required is a summing device.

This means you would take a signal from the sub midrange and tweeter, then the external summing device will summ all the signals together to give one full range signal.

Something like a jl clean sweep (with summing module)
Audio control dql-8
Audison Bit One

Will do the job.

If its just a sub you want to add, you can just pick up the output from the factory amp to the factory woofer. This will be fine as its just the sub it will be powering. Not trying to pickup a signal to power speakers.

The only thing holding me up with my install atm is the Audison Bit One processor as I am waiting for one to land. By far the best line convertor so far. Laptop tuning, phone mute for handsfree, sound comes though front speakers when in phone mode. and will allow cat5 signal connection for audioson thesis amplifiers. No more RCA needed.

Thanks for all that information BIGW.

I just wanted to increase the sub, I'm really happy with all the other speakers but I just think the bass could be beefed up a bit.

By the sounds of it I should just get the output running to the sub and put another amp on it and then I will have full control over the sub, unless of course the problem with the bass is actually that too wide a frequency range is being excluded from it's channel, in which case I am probably not able to do much without major major work.

If you wanted more low end.

1. Remove the factory woofer (or just disconnect)

2. As the woofer is a dual voice coil woofer pick up one set of leads going to the woofer. Tap into these and use a speaker level convertor or a high level input on your amp.

3. This signal will be find and will give you enough range for you sub amp. A nice ten mouled into the rear quater panel with the amp tucked away would yield great results.

4. If you dont want to 'add' anything on, then be satisfied :)

Thanks again BIGW.

I wouldn't mind doing the mod exactly as you said and I'm going to go do some homework on it.

It's funny, one thing I have noticed is that my 250 gives a lot of road noise which seems to drown out the bass, because sometimes when I notice I'm on really smooth road, or stopped the bass sounds pretty good.

I suppose I'd just like to be able to boost the bass only without having the rest of the system louder at the same time.

when you get your signal converter, there are bass controllers you can buy which are remotely operated, so you would have a knob up front to control the bass from the cabin.

Alternatively if you buy a specific mono amp most half decent amps will have a bass remote on them also.

I just mounted mine in the blank next to the headlight adjustment knob