Loe

I've always had better sound quality experience with systems (OEM systems) when the bass comes out of the doors themselves (hence why I asked about the door speaker). My friend has a 300C with the upgraded Boston Acoustic sound system that's rated at 388watts (I think?) 7-speaker sound (two door 8" low-freq woofers, three dash (2 mid-range, one center) speakers, and two rear deck full-range) . The bass was pounding with no lack of low-end frequencies generated to where a rear subwoofer wasn't necessary. I had the same experience in my G35 years ago with a 6.5" low-range front door speaker (Bose); the bass was more than enough to not have a subwoofer.

Link to wiring schematic thread I made: https://www.clublexus.com/forums/is-...ut-wiring.html

I am curious now if it's better to just bypass a LOC and go straight to the Stereo pre-amp wires at the amp harness and splice in RCA converters to hook up to an aftermarket amp for the subs? Most OEM stereo's (at least in luxury car makers) send out a balanced signal pre-amp and is typically a complete full range with no roll-off's in frequency response. Thoughts? I really feel the low-end on my current set-up could be better if I tap into a pair of speakers that don't roll off below a certain frequency.

Bass Mech

i agree that its always better to have as much bass in the front doors as possible. both my corvette and now my GMC sierra had large speakers on the front doors that make up the majority of bass frequencies. you can never have too much mid bass or sub bass up front.
i lMAO at the guys on the corvette forum that take out the bose system and replace a 10" subwoofer speaker in the door with a 5.25 or 6.5" speaker no sub in the rear and they swear it sounds so much better than stock.
its funny how people buy car audio. the vast majority psych themselves into believing it sounds better because their wallet and the lack of cash in it tells them so.
funny story.. my last corvette i decided to do something different. i added the 2 8" subs to the rear but left everything else alone except the HU. the HU had time alignment built in as well as a 7 band eq.
i took my car to several audio shops and gave demos to the sales people and installers i knew and they were blown away with he overall sound quality.
even more dumbfounded to learn 90% of it was stock amplifiers and speakers!

anyway back to your question, i seriously doubt the factory signal coming from the HU is flat, and i suspect its a full volume signal.

looking at the wire diagram i saw only 1 pair of preamp inputs. but i also saw some wires used for what looks to be a serial bus. my guess is that the amplifier actually takes care of the volume balance and fader as well as surround sound and bass, treble. there is a mute wire also that probably comes into play when safety connect and navigation or phone are in use.
so if this is the case you really have only 1 option if you want to revamp the system.
you have to buy 2 JL audio cleansweeps 1 for front and 1 for rear if you want to maintain all the functions.
then you have to re amplify everything. if you going to go through that much trouble you might as well get a processor and time align, eq and crossover everything before you amplify it.

your only other option is to just amplify what you have already done. if you want more then 50 hz you'll need a cleansweep tied into the sub and maybe front door speakers. that will most likely get you the signal your looking for.
this is another reason it is important to use a properly tuned ported sub box. if the bass frequencies going to the factory sub are limited to say 70 hz and below which is actually a fairly decent crossover point, you need a sub that has a good deal of bass at that frequency.
when you seal off the port of your box you end up with a sealed enclosure thats already too small for that sub. your probably getting a roll off frequency of about 60 hz and anything below that is useless.
FWIW when i had my 07 IS 350 i added a sub just like you did. a ported 10 and hooked it up the exact same way you did and it sounded great! i was only running about 200 watts to it.

what you need is a box designed for this application and a little bigger sub.
trust me i have almost 30 years in car audio experience as an installer and hobbyist.

sessionstu

Great thread. Thanks for the insight, Bass Mech. Do you have any experience installing an aftermarket amp in a hybrid? I have a 2013 ES300h. I'm putting a JL Audio XD6001v2 in the trunk to power a JL Audio HO110-W6v3 subwoofer. Seeing that the vehicle doesn't have an alternator, I really don't want to overburden the generator. I'm pretty sure it won't. Just making sure.

Bass Mech

hmm, you know i have not! i never gave any thought to it, but now that you mention it i would guess there must be a voltage regulator someplace to provide 12 volts to everything that needs it.
i have no idea what the current draw capability is or if that is even a problem/ you might do a search online for your question. i am sure the 12 volt.com may have some answers for you or try calling crutchfield.com technical support.
you might have to tell them you intend to buy an amp from them before they will give you any advice.

sessionstu

Thanks. Yeah, I asked an installer friend in Canada the same question. He said it should be alright, but couldn't be 100% sure. I suppose not many people who buy hybrids are putting aftermarket systems in their cars. That's why I'm trolling the IS forum. Nobody in the ES forum is modding their rides. I seem to be the only one. I had an IS350 for 7 years.

Oh, another question. This is an easy one. What's the best way to fix a sub box to the floor carpet in the trunk of a car? Double-sided tape? An adhesive. The JL Audio HO sub box is 50lbs so it probably doesn't need to be permanently bolted to the floor.

Loe

this thread should be stickied lol...thanks bass mech! so it sounds like I need a better sub/amp/enclosure to get the lower frequencies I am aiming for and not go searching for this mystical full range signal from the pre-amp line. The preamp inputs have front/rear +/- for channels from the stock stereo (they are on different pictures on my thread) Ill post links to powered subs shortly that im considering and would like input (JBL, infinity bass link, rockford fosgate).

Bass Mech

i don't know that i would recommend a powered sub. i think you need a box built for your application. if you want to PM me i can probably help you put something together.

Bass Mech

a carpeted box on a carpeted floor will stay put pretty well.
when i built mine i just hooked a bungee cord around it to keep it from possibly tipping over.

but if your worried about it, if its built to conform to the angle of the rear seatback you can usually secure it with an L bracket at the top into the bottom of the rear dash area.
when i do permanent installed i usually screw the box in somehow as part of my install.

Loe

Thank you, I wanted something easy, simple, and quick since I am new to all of this. Once I become more familiar, I will go the custom box route.

I did figure out my LOC RCA issue when hooked up to the subwoofer line; I attached two + wires to the single + of the OEM sub output and the same thing for the negative side and secured it with crimps, it fixed the early bass roll off that I had when I tapped into the post-amp rear speaker wires (the rear speakers must have an approx. 100Hz low-filter signal on them even though they are "full-range" speakers), but I'm still limited to the signal of the OEM amp and doesn't want to play the ultra-low notes (50hz and below), so possibly an LCi2 will help in that area with it's ACCUbass control & threshold settings?

PMing you now...

Loe

Just installed an LC2i, lets just say:

Active LC2i LOC = dirty in --> clean out
Passive LOC = dirty in --> dirty out

What is an AudioContol LC2i you ask? It's an active line output converter (LOC) that taps off a speaker-level signal from your post OEM-amp speaker wire line. I have mine hooked to the OEM subwoofer line. The LC2i eliminates the frequency roll-off that is built into the OEM amp to protect the OEM subwoofer and restores all available signals to its full potential.

It resolved all of the issues I had prior to an LC2i: the bass would roll off around 70Hz, so any frequency below this would gradually curve downwards until the signal is completely cutoff by the OEM amp. This was a problem when using both speaker-level or a passive LOC to an aftermarket subwoofer; you cannot expect an aftermarket subwoofer & amp to perform if the signal is slowly phased out right ? The bass-boost feature on my powered subwoofer could only do so much before distortion sets in. So in goes the LC2i...Well worth the price if you enjoy music to it's fullest. The bass is bigger, rounder, fuller,wider range, and more powerful. Distortion from the subwoofer is eliminated up to 3/4 volume. This is on my cheap Chinese-made Rockville RVB8.1A 8" powered subwoofer (200watt RMS/300watt peak), I can't imagine how it will sound once my JBL powered subwoofer arrives As a test, I set the crossover on the amp to 50Hz and played songs with low bass. The result below 50Hz was that you can continue to hear bass response down to 35Hz where my current subwoofer/amp combo can no longer hit notes with the built in low-pass filter.

If anyone is on the fence, get an AudioControl LC2i, especially if you enjoy good listening. You'll eliminate the issues that are faced due to the limitations brought on my the OEM amplifier.

JB5674

What are your settings on the lc2i? I'm running one now. But I think I can get more from my mrx110 alpine w type r 12 ( 4 ohm ) amp and sub wired to 2 ohm load

Loe

Since I don't turn past 35 on the volume, the OEM speakers/Amps will not dial back the gain in bass volume in relation to the mids/highs. Because of this, I have my threshold screw fully clockwise so that I can use the AccuBASS as my "bass boost" gain. The Bass **** is at the center click (1/2 point), and my AccuBASS is at the 1/4 mark (between fully off, and the center click half-way point). I am playing it safe, because in all reality, I do not get the maximize light flashing until I have the AccuBASS at the 1/2 mark. Definitely use the maximize light as a gauge for how you set up the system to avoid clipping. I am a beginner, so i'll be playing around with adjustments in the next couple days.

Without the AccuBASS setting on, the Bass **** was at the 3/4 mark before the maximize light would flash at volume 45 (63 is the maximum for the non-ML system in case anyone is wondering). For my system, if you turn the Bass **** up X, you should probably turn down the AccuBASS **** - X (where X is the same value), so lets say you turn it up 1/4 turn more, then you should turn down the other **** 1/4 less.

TheDemon

Hi all...I am new to the Lexus way. I have enjoyed this post after i found it even though it is a little older. I have a 2015 and I understand the stereo is the same as the 2014. What I haven't seen here is the speaker dimensions if anyone has them. All I have seen is the ohms. I am just looking to boost the wattage as 293 doesn't work for me. i have the amps to install so I just need to know if these speakers can handle another boost of 400 watts. Thanks.

Loe

Post #31 has a link to a speaker information that you are looking for, along with wiring schematic from the amplifier.

shirosan

Hey guys,

I know we have another section on our forums going too called "Stereo input/Amp output wiring." I wanted to see if we have any new information to share? I'm searching around various forums to see what the best route is for increasing our system's potential. I'm told by my Lexus dealer that the stock speakers are made by Pioneer. So they may have more potential like Bass Mech had stated.

I'm wondering if we can install the ML amp on a premium system even if we don't have all the speakers of the ML system. This might be a better way to get a little more power to the premium setup without any major modifications. Then I'd like to add dual 10" or 12" subwoofers in a custom molded box painted to the color of the car.

I'm working with Dan at Integrity Concepts to build some custom boxes (they can use regular auto carpet or be custom painted) and they will use the dead space in the left/right corner of the trunk. I currently have these installed in my Scion FRS with a custom sound stage and 8-channel DSP/amp done by OEM Audio Plus. I'm hoping to take the information that everyone has supplied here for the Gen 3 IS350 and produce some other ideas.

Keep me posted and I'll keep you posted

Edit: As for the sub boxes, I told Dan that there may be people on the forum interested on these subwoofer boxes which could lead to a group buy or promotional discount during the developmental phase.