YezusLX
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Wow! Thanks! this is great. I can make use of this. Next project after the 150 or so others needed. haha. really appreciate that. I can test these and see if they will give me similar results.
How to: Replacing OEM Subwoofer in 3rd Row (8 Viewers)
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From what I understand, the ML amp is set up for 8ohms, at least to the sub. My only sources for this is my buddy that works for a toyota subsidiary and my own limited personal experience. I put in the JL 6W3v3-4, which is a 4ohm sub and 1. Sounds like garbage (distortion, weird response), 2. Is heating the hell out of the stock amp.
I measured continuity on the stock sub and it measured about 12-13 ohms. This is "free impedance" which usually runs lower than nominal (i think?). The full ML system therefore is either a ~12 ohm system or ~8ohms, with a 12ohm sub.
Current plan is to run two 8ohmx25W resistors in parallel, and then run that in series w the 6w3v3 sub.
I cant find any specs on the ML amp other than an LTC post about it either being 300W or 240W. No indication which, and no indication on Watts/channel. This would be nice to know so I could predict if Im about to burn up my resistors and sub.
Curious to know whether @Patassa and @arkmm are running the 4ohm JL, and how it sounds. The 6w3v3 used to come in an 8ohm version but has been discontinued (iirc).
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I don't know the answers to your questions. I can say that, when I was still trying to use the factory amp, I had my replacement sub wired for 8 ohms.
I addressed a problem with my replacement sub acting funny at post #296. Crutchfield has speced-out the ML sub at around 12 ohms. FYI, using resistors to alter the impedence of a sub has been discussed earlier in this same thread, I believe.
@latetotheparty yes your posts have been very helpful, and Im gonna be using them for inspiration. Thank you!
I guess one point i was trying to make is that i know some of my sound issues are a result of my sub being too low in the ohms.
@brizzle have you had any performance issues with wiring those resistors in series with your sub? Im asking specifically about latency in sound response.
I guess one point i was trying to make is that i know some of my sound issues are a result of my sub being too low in the ohms.
@brizzle have you had any performance issues with wiring those resistors in series with your sub? Im asking specifically about latency in sound response.
I got rid of the factory JBL amp and installed a small 5 channel class d amp to run my system.
Man, sorry about the LATE reply! Literally a decade! Yes, I do work in the industry, have for almost 30 years, and was trained on this stuff. I can't speak for your experience, but nominally, bass drivers in particular typically have a free air DC resistance measurably lower than their rated impedance. Hence my example of a "4 Ohm" woofer with a DC resistance of 3.2 Ohms. That's just an example, to make a point, not an exact calculation.
To clear up another thing that seems, as I read it, to be an error? Two voice coils, whether on a single driver or pair of drivers, regardless of frequency range, work by combining additively if you connect them in SERIES. So that means your amp + connects to the first coil's +, then that coil's - connects to the next coil's +, then that coil's - connects to the amp's - terminal. So in that case, two 4's make an 8, two 8's make a 16, but also a 4 and an 8 make a 12. An example of that is a system that needs three subs, where you'd use a 4Ω dual voice coil wired in series, and a pair of 4Ω single voice coil drivers wired in series, and then parallel that pair with the DVC sub to end up at 4Ω, which is a common impedance for aftermarket car audio.
If you connect a pair of coils in PARALLEL, which is totally valid, then the amp + connects to the + on both coils, and the amp - connects to the - on both coils. In that case, you find the result by taking the reciprocal of the sum of the coil's reciprocals. For example, if one coil is 4Ω and the other is 8Ω, then the calculation to find the equivalent resistance is 1 / (1/4 + 1/8) = 1 / (3/8) = 8/3 = 2.66Ω.
If you are working with two that are the same, then it's just half of one of them. So two 4's in parallel make a 2, two 8's in parallel make a 4, etc.
Hope that helps!
The JL had some heavy distortions when I put it in the stock Pioneer (European models have that instead of JBL) ported subwoofer enclosure. When I blocked the port with a pair of working gloves (essentially making a sealed box) the distortions pretty much disappeared (and also lost a few Hz down low). I have been considering to open the enclosure and measure it and the port and see if it can be adjusted for the JL, but this might never happen. The speaker is rated for 4.2 litres sealed box or 7 litres ported. Seems like the stock box is closer to the former.
I've been reading through this thread and a few others this weekend hoping I could come up with a game plan for my 2000 LC with the twin 4" subs. I was looking at the Skar 8" base tub as an option (using the stock amp and sub wiring) but it's listed at 1 ohm and it sounds like the stock amp is pushing 2 ohm. Can this setup be workable with the right wiring configuration?
BenScott is now this year's official winner of ih8mud's unorthodox solutions awards, acoustics division.
How kind of you to nominate me! I guess seeking out cheap and easy solutions is unorthodox.
YezusLX
SILVER Star
For your official PR campaign after you win the acoustics award. Let's steer away from vocabulary like cheap. Perhaps try " as BenScott a humble boy looking for the most economical option I came up with this unorthodox solution..." Haha, and yes 2(4ohm)= 2 or 8ohm and 2(2ohm)=4ohm or 1 ohm depending on your fancy wiring maneuvers. The same applies to dual voice coil subs as well, but I am sure you are well-versed in these super fancy wiring techniques being the award winner and all
I'll take that into consideration next time..
Replacing the factory amp is sounding like it might be the better approach..I was fine till we got to using old gloves as acoustical dampening. We and The Academy (and all potential passengers) are thankful that your dirty laundry hamper was devoid of Holy Socks.
Did you get this straightened out? I have an 05LC with stock single JBL sub and amp. I also cannot find a definitive answer on the correct ohm sub to order.
PM sent…
Let me start by saying I’ve read and searched as much as I can, and I am not an audio/electrical guy whatsoever. So in July I replaced the front speakers/tweeters and headunit with a KENWOOD. I used a metra bypass harness from crutch field and everything has been working great.
i never paid attention to the sub cause it hardly made a noise except on certain songs. Tried hooking up the Skar 6.5” 4ohm last night and I wasn’t getting anything from it.
My question is, when you bypass the amp, do you lose the function of the sub? What do I need to do to run the new sub?
i never paid attention to the sub cause it hardly made a noise except on certain songs. Tried hooking up the Skar 6.5” 4ohm last night and I wasn’t getting anything from it.
My question is, when you bypass the amp, do you lose the function of the sub? What do I need to do to run the new sub?
Just got off the phone with Crutchfield. They said in my 2005 LC with JBL and nav that the factory sub is 3 ohm.
They sell a Kicker in 2 ohm and 4 ohm. He said I can switch the wiring (series vs parallel) and use the 2 ohm and it would be just slightly overloading the amp. Or leave the wiring as is and use the 4 ohm. May not be quite as efficient but should work fine and won’t put any extra load on the amp.
The depth and diameter are both very close. Might need a little trimming.
I ordered the 4 ohm. I’ll report back.
They sell a Kicker in 2 ohm and 4 ohm. He said I can switch the wiring (series vs parallel) and use the 2 ohm and it would be just slightly overloading the amp. Or leave the wiring as is and use the 4 ohm. May not be quite as efficient but should work fine and won’t put any extra load on the amp.
The depth and diameter are both very close. Might need a little trimming.
I ordered the 4 ohm. I’ll report back.
Installed the 6.75” Kicker sub today. Fit perfectly into the housing. Had to run in 8 new screws. Didn’t work the first time I hooked it up. Based on a post in this thread I switched the polarity on one pair of wires and that did the trick. Bonus, the sub has spring loaded connectors for the wires, no crimping or soldering needed.
Looked like the panel would fit fine but after getting everything snapped back in I discovered the back of the grill is just barely touching the sub. Need to shave a little plastic off the grill behind the fabric. Looks like an easy fix but ran out of time. Sounds fine for an old stereo. Definitely worth the $100.
Did you wire the 4 ohm sub in series or parallel? Thanks.
In the process of installing a new sub in my 99 LX470. It's a standard Nakamichi system. I replaced the system with Sony AX5500 unit and Infinity Speakers (front and passenger doors). Didn't replace the stock OE Amp. So, I guess, only thing stock are the speaker wires and amp. In terms of sub, I didn't really know exactly what I had to work with until I took the panel off...also, not savvy in sound system so learning as I go on this one.
Sharing for those with similar set up. The OE sub is 4 ohms with one set (one red and one black) of speaker wires.
I purchased Kicker 6.75" but the wrong one from Crutchfield. It was dual 4-ohm voice coils. So, I called today and they are swapping it with dual 2-ohm voice coils so that I can wire it as 4-ohms. When I get the new one, it will be wired as series per Crutchfield's recommendation (and not parallel) to make it 4 ohms.
In terms of fit, it was simple and easy. Will post the final pic when I get the replacement.
Kicker Manual (wired as series)
Dual 2 ohm voice coil Sub = 4 ohm load (which is what I want to match to original)
Dual 4 ohm voice coil Sub = 8 ohm load (which is not what I want)
Sharing for those with similar set up. The OE sub is 4 ohms with one set (one red and one black) of speaker wires.
I purchased Kicker 6.75" but the wrong one from Crutchfield. It was dual 4-ohm voice coils. So, I called today and they are swapping it with dual 2-ohm voice coils so that I can wire it as 4-ohms. When I get the new one, it will be wired as series per Crutchfield's recommendation (and not parallel) to make it 4 ohms.
In terms of fit, it was simple and easy. Will post the final pic when I get the replacement.
Kicker Manual (wired as series)
Dual 2 ohm voice coil Sub = 4 ohm load (which is what I want to match to original)
Dual 4 ohm voice coil Sub = 8 ohm load (which is not what I want)
