JR Ewing

I picked up a 98 gs400 with the non-Nak stereo a few months ago, and honestly I'm quite impressed with the clarity and overall quality of the sound with one exception - it lacks sufficient bass. Is it feasible make the following changes and expect any level of success:
1. Replace stock sub with a drop-in aftermarket free air design sub
2. Put a line out converter on the factory sub output and feed the signal to a mono-sub amp to drive the new sub (or use an amp with speaker level inputs)

If this will work, what is a good model of sub for this application, and where can a remote turn on lead for the amp be tapped. I know this is a lot of information but I really appreciate any help. I just found this forum today and it is great!

Mean Gene

JR - Try looking in the Lexus Q&A section. Percy & I compiled some general information concerning the audio systems.

tmilne

JR ,

An installer I spoke with recommended just such a set up. Although there seems to be few free-air subs. He suggested one alternative: remove the stock sub and leave the hole open. Then place a sealed sub in the trunk (rear facing) with a dedicated amp and line out converter. I'll have to hear this before I bite., but its worth considering and it is simple ( except you do lose modest trunk space).

Also, is it possible to construct an enclosed sub structure that still fires up like the stock sub with a hanging box? How would this or should this be done?

Tom

Mean Gene

Tom & JR - If U don't want to lose trunk space at all, the JL 10IBU4 with about 125 watts on it will surprise U, especially if U've never used a free-air sub. It's one that I've had before & with great sonic pleasure. U can install a small sealed box firing thru the stock 10" hole - just be sure & secure it well & might want to consider a layer of Dynamat between the box & the deck to minimize rattles. For some extra security, just build the box to rest on that ledge in the very front of the trunk but it might then be too big for a 10" woofer's airspace requirements. I'm not real high on firing the sub into the trunk - it invites rattles ( from the license plate frame & the spoiler ) & it's somewhat of an untuned bandpass enclosure for me but that's just my opinion.

JR Ewing

Thanks for all the replies! Sorry about not checking the general questions section first. Now that I have more info I plan to get the JL sub and use a converter/mono sub amp setup. Mean Gene - Does the JL need to be in a small sealed box under the deck, or is it OK if the rear is exposed to the entire volume of the trunk like the stock sub? I just want to add some quality to the lower ranges so I think a single JL 10 will suffice. Thanks again for the help.

Mean Gene

JR - The IBU4 is an infinite baffle ( thus, the IB designation ) or "free-air" subwoofer. It is designed to be used with the trunk as it's enclosure just as the factory sub is. Sonically, a sub in a sealed box would be better as the interior volume of the enclosure remains constant & is truly "sealed" as opposed to a trunk which relies on the weatherstripping to provide it's seal which is rarely leak-free, even on a Lexus. Don't get me wrong - a good free-air sub like the JL IB series is a considerable improvement over the factory ( Pioneer ) woofer, especially once U add an amp. However, IMO, a small sealed box ( .5 to .75 cubic feet ) with a JL 10W-3 in it would yield tighter, more responsive bass than the IB & really not hang down much farther than the magnet of the IB. The choice is yours but either way should make U happy. Enjoy!

JR Ewing

Well, I picked up the JL Infinite Baffle sub and would like to mount it, but I can't figure out how to take the grill/old sub out. I don't want to damage anything so before I keep trying, I figured I'd ask if anyone has an easy procedure for doing this, and also where is the easiest place to tap a lead to connect to the remote turn on of an amp placed in the trunk. TIA!

Gs400TRD

well check the FAQ section, and make sure you have the day off....even better if you have a good friend to help

I am going to probably do the same thing, but If it is not too difficult to get a custom box made, then I plan to install a JL 10" (or 12") sub in the box, and probably get a 150 watt mono amp for it.

JR Ewing

I looked through the faq section and that's just info about the board. The Q&A section has lots of good info but nothing about the actual process of changing out the factory sub. Am I going to actually have to remove the whole rear deck? That could take all day, you're right. Does anyone have a basic process for doing this, or where to start? Thanks again.

tmilne

https://www.clublexus.com/vb/showthr...threadid=13575

JR Ewing

Thank you! That is exactly what I was looking for. Thank god for the internet!

Mean Gene

TM - And I'm sure that Percy thanks you as well!! He's so patient about reposting on sub & speaker replacement - good to have a technical guy on board!

JR Ewing

OK, I got the sub in (JL audio 10IB4), and...well, it sounds just like the factory sub, but I'm sure that's because I have not added the amp yet. I want to put it in, but I'd like to know the best place to tap remote turn on power and the recommended route for the main power lead from the battery. After this, I promise not to bother you guys anymore (for a while).

Mean Gene

JR - It was easiest to run the cables down the passenger side since that's where the battery is located & I think there's a small hole in the firewall thru which U can run the wire/interconnect. For the remote turn on, that's kinda up to U - where do ya have the LLC located? In spite of it's sonic limitations, the factory free-air sub's decently efficient but it would need to be, what with only about 50 watts going to it. Believe me - things WILL wake up when U add an amp! BTW - which amp didja choose?

JR Ewing

At the store where I picked up the sub they suggested a JL 500.1, but I just want to pick up a simple kenwood sub amp, probably a kac-819. This one has speaker inputs and a built in x-over ( I like simplicity). I'll definitely hook it up tonight. I am planning on picking it up after work today (it's about 9am here now). Is there any reason not to use this amp? I've used many kenwood amps before, including a 719 in my SupraTT to drive a single polk 10. They've always been good and reliable, so I can't think of a reason not to. What is an "LLC"? I checked the Q&A and this wasn't listed.