'05 limited - JBL subwoofer questions

[Quiv]

Hi all,

Just got my runner 2 weeks ago and i'm planning on removing the JBL system and starting over. I am curious after i remove the stock 10' woofer, will I have enough room to stuff a sub amp in there? Anyone know the dimensions of the area that enclosure takes up?

Has anyone done this? what worked out - how do you recommend mounting the amp inside there.

Thanks,

 

[4runner91]

I recomend planning on an 8" subwoofer (thats the size of the stock woofer).

 

[XMAN05LTD]

I wouldn't try stuffing an amp in there. But if that's what you really want I would have it custom made because there should be some kind of cutting going on.

 

[SConnors]

Disconnect the center speaker and listen to it for a week... you probably won't feel the need to upgrade.

 

[majewski]

speaker disconnect

Hey SConner, what differences did you notice when you disconnected the center front speaker? Does it sound any different now when you turn the surround on or off?

That has been the one issue I have that it seems too...tinny?

 

[4runner91]

I wouldn't try stuffing an amp in there. But if that's what you really want I would have it custom made because there should be some kind of cutting going on.

Was looking at your sig and notice you had the JBL system. There is 10 speakers not 8.

 

[SConnors]

The center speaker presents a few problems:

1 An excessive amount of sound fron 5khz to about 16khz

2 The signal from the center speaker is a simply summed signal. The wires from both the left and right channels are both connected to the speaker terminals, destroying much of thestereo imaging. Kind of a poor man's Dolby Pro Logic...

3 With frequencies in this range it is oftem beneficial to deaden reflections within the first 1ms or so (primary reflection points). In home theaters we often try to minimise primary reflections. Toyota unwittingly provided a primary reflection point (windshield) within inches of the driver. This contributes to a perceived "harsh sound".

The elimination of the sound from the center speaker helps with all of the above issues, but leaves the frequency response still off a bit. The resultant frequency response is down slightly at 16khz which can be helped with a click or two of trebble added in the sound controls. Otherwise, it's a pretty good curve (not flat, more of an inverted bell curve as it should be)

The effect of eliminating the center channel has the effect of increasing the subwoofer sound level with respect to the original overall sound.

I did this and was initially unsure if I liked the effect. The imediacy of the sound was reduced, and volume levels had to be increased to make up for the change. After a week, I reconnected the center channel and was repulsed with the resultant sound, so it's disabled for good.

The sound of the stock sub is much better with the higher required overall volume level (# on the Head Unit) with respect to stock.

On another note, I think the amplified signal to the sub is rolled off (~30hz?), but I have to measure it to be sure.

If you want to try disconnecting it, it's reversible. Follow Castaluci's (sp?) directions for removing the stock head unit, but don't actually remove the head unit. Instead, look for the speaker connector above the HU on tword the left. Disconnect and see what you think.

BTW, my settings are fader centered and 1 click of extra treble on the 07 NAV... Should be similar to any JBL on the 4Runner.

Sean

 

[Uneek]

Was looking at your sig and notice you had the JBL system. There is 10 speakers not 8.

The JBL Synthesis system has 10 speakers. Some JBL navigation systems have 10 (2003 and some 2004s), and others have eight speakers (2004 and newer).

 

[SConnors]

The difference between the above systems is the existance of the 200mm speakers in the rear pillars. These are the same speakers used for the fromt components and the center speaker, with the exception of the center speaker wiring differences already mentioned. That said, I'm speaking of the 8 speaker setup when discussing my measurements and modifications.

 

[majewski]

Center speaker

Thanks, Sean.

Sounds like you have a bit (or a lot) of audiophile in you. I will disconnect the center speaker tonight. I put in an aux interface kit for my Sirius radio, so I'm pretty sure I can disassemble the dash with my eyes closed now.

Essentially, I like the imaging with the surround on, but hate what comes out of the center speaker. Do you think replacing that with a higher quality speaker, or maybe being able to control the volume there would help? Or is the proximity of the windshield just going to make it sound bad no matter what?

I'll unplug the center speaker tonight and see.

 

[drmorbius]

The difference between the above systems is the existance of the 200mm speakers in the rear pillars. These are the same speakers used for the fromt components and the center speaker, with the exception of the center speaker wiring differences already mentioned. That said, I'm speaking of the 8 speaker setup when discussing my measurements and modifications.

Those rear pillar speakers are also wired to a single channel. They are wired to pins 2 and 11 on the amp.

 

[T4RUSAF]

Hi all,

Just got my runner 2 weeks ago and i'm planning on removing the JBL system and starting over. I am curious after i remove the stock 10' woofer, will I have enough room to stuff a sub amp in there? Anyone know the dimensions of the area that enclosure takes up?

Has anyone done this? what worked out - how do you recommend mounting the amp inside there.

Thanks,

You can easily put an amp in that compartment. People have gone as far as putting a 500/5 in there. I had a 500/1 before I figured that that was too much power for my single 10" stealth sub. As of now, I have a 250.2 (I think) powering my stealthbox. do a search on "flyingdutchman" cuz he did a full 5-channel amp install in that section.

 

[majewski]

THANKS, SEAN. GREAT TIP!!

The center speaker presents a few problems: ...If you want to try disconnecting it, it's reversible... Disconnect and see what you think.

Sean

Great tip, man! Finally got some time to take the dash and radio back out and disconnect that center speaker on my JBL Synthesis system. That miserable sound front center channel was just making me crazy. And as you said, defeating that also boosted the base considerably.

Guess we now have 9-speaker JBL systems, but I am a ton happier because it sounds a hell of a lot better and didn't cost a dime.

 

[Ruffian]

Disconnect the center speaker and listen to it for a week... you probably won't feel the need to upgrade.

Hi guys,
Thanks for this posting. So, how would you reccomend this being done to a person who doesn't have training for electronics? Where are these plugs located? I have been wondering why it sounds off. Via the NAV, I have tried changing the output to the speakers by moving it back, off centering etc. Finally gave up and was contemplating going to a auto audio shop and speaking with a tech as I was getting the feeling the JBL speakers were not as good as cracked up to be.
Thanks again for this post! Even those this site has made me want to spend more money, it's nice to have these posts that help you to save it...well, only to spend on other mods!

 

[AK602]

If you shut the surround off does it do the same thing? On my 04 there is a choice on the sound menu to shut the surround mode off ( I have NAV )

 

[majewski]

center channel speaker defeat

No, regardless of whether you are in surround mode or not, that center channel still is putting out that harsh sound. Put your hand up there or better yet, jam a pillow up there and you will see the resulting sound is much more pleasant.

It's really not hard to get the center console pieces out pull the radio, and unplug the center speaker. Literally took me 15 minutes from start to putting it all back together.

You'll need to boost the treble and possibly the midrange to compensate (whatever suits you) but the bass sounds much heavier now.

 

[XMAN05LTD]

Was looking at your sig and notice you had the JBL system. There is 10 speakers not 8.

I see your point but Uneek is correct...I have the NAVI system, I don't have the two top rear speakers...I have the rear side view mirrors in place of those. Oh, & I have since changed my sig.

 

[AK602]

OK so heres what I did. I put a rubber no skid mat that i usually keep on the burger tray over the center channel speaker. I cannot believe the difference in the sound of the system. I guess the next question is, Is there anyway to disconnect the speaker without pulling out the whole stereo? Does the speaker grill lift off? Can this speaker output be used to run 2 speakers somewhere else in the truck?

Aron

 

[SConnors]

The grill will lift off... but I broke a couple of the tabs when I removed it. The best way to do it is to take the 15 minutes to pull the dash apart and disconnect the speaker.

I do NOT recommend trying to pull the grill off, as I had a hard time. Opening the dash is the completely reversible way to go.

I'll write up a tutorial complete with before and after measurements in a couple of months, but right now I have a 20 unit load for my final semester (Mechanical Engineering). There's very little time for sleep right now, these forums are a guilty pleasure for me. The other day I put SAW C/Os on instead of hitting the books and I'm still paying for it.

Sean

 

[AK602]

Very very cool. Thanks.