Added a sub and amp, how to get rid of boomy bass.

I have a 2008 Sequoia with the factory JBL Nav system.

I recently installed a JL 500/1V2 amp, a 12W3V3 sub in a ported box to JLs specs with a JL LoC-22 tapped in at the rear door speakers after the JBL amp. With the factory HU at volume 47 I used a 0dB 50Hz test tune to set the LOC and a -10dB 50Hz test tune to adjust the amp gain. It had plenty of bass but it sounded like sh(T. Even with the amps gain all the way down the bass was overly boomy at low and high volume and I heard the bass more in my ears than felt the bass in my body and seat etc if that makes sense.

I tried contacting ********* and asked about their DSP but they recommended I just replace the factory HU. I don't think anyone with a Sequoia has ever contacted them because they don't even list a Sequoia on their site so I felt like it was the easy reply.

I've seen MANY Tundra owners keep the stock JBL HU and just add a amp and sub so I know you don't have to replace the HU. Someone on an audio forum said this about the 12W3V3;
"the jl has a bump in frequency response, done for marketing reasons, to make it appear louder. it makes the bass from it unprocessed sound boomy, but processed it does sound very good and is built well."

I don't know whether that's true or not but it sounds like the issue I'm having so I returned the 12W3 and am thinking of getting a RF P3 sub to try out but I don't want to be in the same situation. Has anyone else had an issue with boomy bass after adding an aftermarket sub and amp? I'm wondering if replacing the JL LoC-22 with the LC2i would make a difference?

 

In general, a sealed box will make it more tight and punchy. The ported one makes it deeper and boomy.

I can't speak to your specific equipment though.

 

I get that but this is not normal. I've had a few ported (and sealed) enclosures in other cars and in my HT and this type of bass reminds me of a crappy made band pass box that's all boomy bass. Something isn't right with this setup. I don't know if it's the cabin or the HU / factory amp?

When I open the rear cargo door in my garage I don't hear the boominess in the garage or in the house, it's sounds like normal bass. Once I sit in the drivers seat and close the rear cargo door the bass sounds nice as the door's closing but once it fully closes and locks, instantly the BOOOOOOOOMMMM starts. I'm not sure if that means it's the interior cabin that's causing the boominess, if so maybe a sealed enclosure would fix it??? I don't want to start throwing money down the drain if it won't help though.

If I didn't like the stock system I would just change everything out but the stock system isn't that bad to me, it just needs a little more punch in the bass dept. With 0 being no bass and 10 being an obnoxious system, I'd say the factory bass is on a 2-3 and I'm looking for a 5. Nothing annoying to where 4 cars over will hear it or it'll rattle my neighbors windows as I'm driving through the neighborhood, just something where I can really feel the bass.

For such a simple project it's turning into a headache!!

 

I dont see the problem with the bass...Just kidding. Have you tried turning down the gain on the amp? that is basically the volume knob for it. Otherwise James can get you a DSP for your setup.

 

I'd replace the JBL headunit if it were me. Think you're fighting a losing battle. I have never been impressed with JBL because of the bass levels and overall sound quality. All you're doing is amplifying a subpar HU. But that's me. Anytime I'm upgrading a system, I replace everything. I figure most quality aftermarket HUs are a huge improvement over any stock system.

 

Your method of setting the loc and amp gains sound pretty spot on. I personally prefer using a -6db 40 hurtz tone. The difference between 40 hurtz and 50 I doubt would be audible, but the -10db and -6db is noticeable and is worth experimenting with.

Some possible adjustments/considerations:
-any eq, base boost, loudness, ect, on your head unit and amp, set them to flat or off.

-subsonic/infrasonic setting. It could be a little low which can muddy up the bass below the enclosure tuning.

-Low pass filter:
If its set to high compared to the enclosures tuning, it is possible that it can produce audible harmonic distortions/resonance.

A couple rather easy things to also try:
-Plug or stuff the port temporarily. It won't act exactly like a sealed box but it can give you an idea if that might be closer to the sound you are aiming for.

-poly fill. Your box is built to spec then that should have you around 1.5 cf of internal airspace after all displacements have been taken into account. You can add between 1.5 pounds of polyfill and up to 2 pounds. 2 pounds being the max.

You can glue or staple it in layers to the walls. Adding some speaker cloth to the port opening inside the box is a good idea if you decide to try this. Only $2-3 at Walmart last I checked for a couple pounds.

You should hear a difference, be it for better or worse, doing any of the suggesting above with only a few bucks and some free time invested. A $250 parts express DSP or a $300ish minidsp would also provide the needed options to help correct the issue also. Which in the realm of dsp's, are crazy cheap and pretty damn capable. Just throwing those out there in case you had already considered getting a DSP.

 

Do you have any of the loudness, bass boost, etc settings turned on? Not sure if those are included with the JBL headunit, but they’ll distort the hell out of your sound. I’m definitely no expert in audio, but everything I’ve ever read said to keep those off. I know it’ll wreck my sound if I activate them.

 

What is your audio source? Radio, phone?