When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi All, just thought I'd share my last mod. I replaced the woofer with an aftermarket speaker I purchased from PartsExpress
Goldwood GW-8PC-8 8" Delmar Series Heavy Duty Woofer 8 Ohm - part number 290-314 https://www.parts-express.com/goldwo...8-ohm--290-314
Not quite drop-in but pretty darn close. The only modification to the mounting bracket was trimming the screw shrouds just a hair as the new speaker is about 1/8” larger in diameter. That’s the pic with the hacksaw. Just use a fine blade and cut off a 1/16” slice. Slightly longer screws will also be needed as the cover doesn’t fit down into the speaker face like the original. I used some latex caulk on the underside of the speaker (silicon would work better but didn’t have any on-hand.) As my stock speak had completely separated from the foam surround, I removed the electrical lead and installed in the new speaker for plug ‘n play. Careful where you mount the speaker in the mount or the short leads won’t make it to the mount thingy (like mine doesn’t)
I was really surprised to see how puny our stock woofer is
Replacement below
Separated from foam below
Trimming the cover below.
New screws:
New speaker in mount:
and installed (notice leads were a little short to use the clip mount, use a little more care than I placing the speaker in the mount)
Looks like you went with 8ohm. Stock is 16ohm. So this isn't technically a drop in "perfect" replacement. Use the search and you can find more on the discussion about deviation from stock resistance and possibly damage to the ML amp, which retails around $2k. Please read more here https://www.clublexus.com/forums/sc430-2nd-gen-2001-2010/692831-door-soundproofing-and-speaker-change-2.html
Well crap... I thought our systems were 8 ohms! If I can quote Homer, DOOH!
First, thanks for letting me know. I did a lot of research here but somehow missed that thread. Now with my crash course in ohm's, it seems to me that I can toss a 8 ohm tweeter in series with this woofer and bring the resistance up to 16 ohms, is that correct? The systems sounds pretty good, what are the real world probability of amp damage running the 8 ohm as is?
Looks like you went with 8ohm. Stock is 16ohm. So this isn't technically a drop in "perfect" replacement. Use the search and you can find more on the discussion about deviation from stock resistance and possibly damage to the ML amp, which retails around $2k. Please read more here https://www.clublexus.com/forums/sc4...-change-2.html
Shawn - I think the stock ML sub is rated something really weird like 12 ohm. I replaced mine with a 16ohm speaker with no issues. I'm guessing an nominally rated 8 ohm speaker would work just fine. Speakers are rated "nominally" with a specific ohm rating (essentially a measure of electrical resistance) but any speaker's ohm rating varies significantly by frequency. Depending on the new sub's sensitivity an 8 ohm sub may have to be adjusted down a little, while a 16 own sub might have to be adjusted up a little in terms of bass adjustment at the head unit.
Likely to cause problems with the amp would be using a 4 ohm or even worse a 2 ohm sub.
Shawn - I think the stock ML sub is rated something really weird like 12 ohm. I replaced mine with a 16ohm speaker with no issues. I'm guessing an nominally rated 8 ohm speaker would work just fine. Speakers are rated "nominally" with a specific ohm rating (essentially a measure of electrical resistance) but any speaker's ohm rating varies significantly by frequency. Depending on the new sub's sensitivity an 8 ohm sub may have to be adjusted down a little, while a 16 own sub might have to be adjusted up a little in terms of bass adjustment at the head unit.
Likely to cause problems with the amp would be using a 4 ohm or even worse a 2 ohm sub.
Guys, we have had this discussion before. Please stop with the ohms resistance. That is incorrect. Speakers are rated in ohms nominal impedance. Resistance is just part of the equation for calculating impedance. There is inductive reactance also. Putting something of similar ohm rating is not needed or advised. You cannot put an 8 ohm resistor in series with an 8 ohm speaker and get the effect you want. The total resistance of a speaker changes with the frequency that is being applied at the time. The OP should be fine with the speaker he installed.
Jabberwock, I used your quote just for effect. Not saying you are wrong.
Googled up Ohm Cooking 101 that had this about using a speaker with lower ohms than the amp:
"while the speaker output voltage significantly falls, the flowing current only marginally increases. This will alter your tone too, but in the exact opposite way from before – you’ll get a drop in your mids! If you’ve got a cab that is way too mids-heavy, then, this can be the perfect method to better balance your overall tone. Because this combination can help lessen the self-induction effect that might occur in your tubes, it is generally safer to use than the example in Case 1. In terms of the amount of mismatching you can get away with here, we’d go with the 25% rule: so, for instance, don’t connect a speaker with less than a 4 ohm output to a 16 ohm amp output!"
So I'm leaving the woofer as-is and "hoping for the best" (just like my second daughter did when learning to back a car up...and onto a curb)
Now I didn't post this (and am hesitant now after my ohm-up) but I replaced the rear side speakers as well. They are 8 ohm coaxials with separate inputs for each driver that I wired in parallel. Now I think it best to pull the back seat again and rewire them in series. Wouldn't that make them 16 ohms?
I really appreciate this help, Bill
Googled up Ohm Cooking 101 that had this about using a speaker with lower ohms than the amp:
"while the speaker output voltage significantly falls, the flowing current only marginally increases. This will alter your tone too, but in the exact opposite way from before – you’ll get a drop in your mids! If you’ve got a cab that is way too mids-heavy, then, this can be the perfect method to better balance your overall tone. Because this combination can help lessen the self-induction effect that might occur in your tubes, it is generally safer to use than the example in Case 1. In terms of the amount of mismatching you can get away with here, we’d go with the 25% rule: so, for instance, don’t connect a speaker with less than a 4 ohm output to a 16 ohm amp output!"
So I'm leaving the woofer as-is and "hoping for the best" (just like my second daughter did when learning to back a car up...and onto a curb)
Now I didn't post this (and am hesitant now after my ohm-up) but I replaced the rear side speakers as well. They are 8 ohm coaxials with separate inputs for each driver that I wired in parallel. Now I think it best to pull the back seat again and rewire them in series. Wouldn't that make them 16 ohms?
I really appreciate this help, Bill
Please understand, wiring two 8 ohm speakers in series does not make a 16 ohm speaker. It is not like that. This is not resistance, it is impedance. I can't seem to say that enough.
Please understand, wiring two 8 ohm speakers in series does not make a 16 ohm speaker. It is not like that. This is not resistance, it is impedance. I can't seem to say that enough.
You are going to have to provide some more detail on what you are getting at. Readily available wiring diagrams (available on multiple reputable internet sites and in audio tech literature) show wiring multiple speakers in series doubles nominal ohm rating. Two 8 ohm speakers wired in series look like a 16 ohm impedance load to an audio amp while the same two speakers wired in series look like a 4 ohm load.
Text and diagram below from Eminence speaker company support site -
Wiring Diagrams
It is important to match the speaker load with your amplifier’s output impedance for a couple of reasons. One reason is that you will get maximum transfer of power. The other reason is that you can sometimes approach dangerous conditions for your amp if you have the incorrect load. When in doubt, it is safer to go higher in impedance to help protect the amplifier. The manner in which your speakers (in a multi-speaker system) are wired together determines the overall impedance.
Wiring Configuration for 2 Speakers in Parallel
Two 4 ohm speakers = 2 ohm load
Two 8 ohm speakers = 4 ohm load
Two 16 ohm speakers = 8 ohm load
Wiring Configuration for 2 Speakers in Series
Two 2 ohm speakers = 4 ohm load
Two 4 ohm speakers = 8 ohm load
Two 8 ohm speakers = 16 ohm load
The idea is to get close to stock in impedence/resistance. You call call the term in whichever nomenclature you choose, point is try for 16ohm which is what Lexus is pushing to the sub. Over my many years here, and first owner of a 2002 with currently 57k miles, and tons of mods, please know that I've seen enough posts of the ML amp burning out and the headaches that followed with the gps system. Why risk it? Makes no sense. I came up with the idea to use a dual voice coil sub wired in series (8ohm per coil). I've used mine for nearly 10 years without failure and great sound and I blast my system regularly. Reinventing the wheel might increase the risk. If someone has the income to replace a fried system, then more power to them. I follow this forum to learn new things and take advice from those that have experienced the ups and downs of modifying the sc430. There are enough gremlins in this car that cost too much to repair/replace. I won't risk the amp and thus chose to stay with the recommended 16ohms. I hope common sense dictates my rationale behind this. I've had an amp burn out from improper impedence before in my 99 Sebring running a bridged 4ohmx2 200 watt Power Acoustics amp pushing two Rockford Fosgate 10s wired incorrectly at 2ohms. That amp got hot enough to boil water. I won't risk it again. With that said, good luck in whichever decision you make.
Also please read this in regards to what happened in my experience in removing the entire "OEM "subwoofer and replacing with a line out converter running to a JL Audio A1200 250 watt Monoblock amp pushing a JL 8w3v3-4 speaker in the stock location. Thus losing that 16 ohms all together. All other speakers in the cab went to half gain (half volume, ie. what the previous decibels were at 50% now required 100% of volume **** to reach the same decibels). Thus I had to put back the modified 16 ohm subwoofer, and then piggy back the line out converter for signal to the JL amp and do a custom trunk box for the JL 8w3v3-4 speaker. I now have two subwoofers: the modified 16ohm DVC subwoofer running off the ML amp, and the trunk mounted boxed JL subwoofer running off the JL amp.
I think there is one error in your statement, please let me know if you agree.
Originally Posted by Jabberwock
You are going to have to provide some more detail on what you are getting at. Readily available wiring diagrams (available on multiple reputable internet sites and in audio tech literature) show wiring multiple speakers in series doubles nominal ohm rating. Two 8 ohm speakers wired in series look like a 16 ohm impedance load to an audio amp while the same two speakers wired in series PARALLEL look like a 4 ohm load.
Text and diagram below from Eminence speaker company support site -
Wiring Diagrams
It is important to match the speaker load with your amplifier’s output impedance for a couple of reasons. One reason is that you will get maximum transfer of power. The other reason is that you can sometimes approach dangerous conditions for your amp if you have the incorrect load. When in doubt, it is safer to go higher in impedance to help protect the amplifier. The manner in which your speakers (in a multi-speaker system) are wired together determines the overall impedance.
Wiring Configuration for 2 Speakers in Parallel
Two 4 ohm speakers = 2 ohm load
Two 8 ohm speakers = 4 ohm load
Two 16 ohm speakers = 8 ohm load
Wiring Configuration for 2 Speakers in Series
Two 2 ohm speakers = 4 ohm load
Two 4 ohm speakers = 8 ohm load
Two 8 ohm speakers = 16 ohm load
Obviously I'm not the alpha nerd on this subject (man I hate riding in the back) but in the previous correction, don't you mean
while the same two (8-ohm) speakers wired in series PARALLEL look like a 4ohm load. not 8?
Now, I installed a pair of coaxial speakers in the rear of my car that have separate connections for the low and the high drivers. I just jumped the pos/pos and neg/neg connections for parallel connection. Should I pull the back seat out again and rewire them in series? Jump one pos to neg and amp leads to the other pos and neg connectors? In my layman's view here, it seems the will pull more power and run the amp hotter wire the way they are currently?
.
Obviously I'm not the alpha nerd on this subject (man I hate riding in the back) but in the previous correction, don't you mean
while the same two (8-ohm) speakers wired in series PARALLEL look like a 4ohm load. not 8?
Now, I installed a pair of coaxial speakers in the rear of my car that have separate connections for the low and the high drivers. I just jumped the pos/pos and neg/neg connections for parallel connection. Should I pull the back seat out again and rewire them in series? Jump one pos to neg and amp leads to the other pos and neg connectors? In my layman's view here, it seems the will pull more power and run the amp hotter wire the way they are currently?
.
You are correct. I only meant to change series to parallel. I was up too late last night after a long clinic shift. Thanks for the correction. As for your question, maybe if you drew up a schematic of what you have currently, then we can help to shed some more light on the situation. Just mark each single voice coil speaker with positive and negative terminals, and what you've connected and where. As for generation of heat from the amp, from what has been explained to me and from my experience with my Sebring if the combined (either paralleled or seriesed) ohm rating of the load is lower than the recommended amp impedence, the amp overheats (ie. running 2ohm load for a 4ohm rated amp). Can't say much to the opposite (ie. running 16 ohm on a 4ohm rated amp) and what will occur. Also note this... in layman's terms the lower the impedance, the more "dirty bass", higher then impedance the more "pinpoint" punch results. Thus 2 ohm sounds loud and massive, where 16ohm hits on emphasized bass. Thus why I feel that Lexus went with 16ohm sub and 8ohm speakers in the cab. Gives more of a refined sound system with emphasized lows rather than the ghetto hoopty shaking the block with every beat.
"Please understand, wiring two 8 ohm speakers in series does not make a 16 ohm speaker. It is not like that. This is not resistance, it is impedance. I can't seem to say that enough"
This statement is in fact false and my knee jerk reaction to write it should not have happened. I had read over the years many people say they to put a resistor in series with the speaker to increase the ohm rating. That does indeed increase the ohm rating the amp sees but does not accomplish what the individual is trying to achieve. This is what I was referring to, but I did not say that. I stand corrected and I appreciate it being pointed out. To Shawn's comment about impedance having an effect on frequency response. I was in audio in the 70s and I can say unequivocally that the "dirty bass" relationship to impedance is not correct. I worked in a high end audio shop in Raleigh NC and we ran 4 ohm speakers on amps rated at 8 all the time with no difference in frequency response. You do get a bit more volume when you lower the nominal impedance and the amp produces a bit more heat. If the amp can dissipate the heat there will be no problem That is it. The nominal impedance has nothing to do with a more refined sound. Many first class auto speakers are 4 ohm. Also, the correction Shawn made to Jabberwock's post is correct. Two 8 ohm speakers in parallel give you a 4 ohm nominal impedance. I think that was what Jabberwock meant.
Just thought I would contribute a little to this thread. Read all I could find on how to deal with a busted Mark Lev woofer. Did not want to buy a $200 part for OEM and wanted to stay 8 Ohms like OEM. Checked out Goldwood because of what others have said in this thread. Found Goldwood GW-S650/8 6-1/2" Poly Cone Woofer 8 ohms 170 Watts 85.7 dB 1" Coil which seemed to be about the right size and was not too thick given how little space we had to work in there. Got them for $25 each shipped to me off eBay. Paid a local audio shop to fabricate an adapter bracket and do the install. So I replaced both my drivers side and passenger side ML woofers for a grand total of about $250 labor and $50 parts. Sounds just fine to me but I would add I am not an audiophile. All I wanted was for my crap ML woofers to stop hissing at me and I can say objective achieved. I saved both original ML woofers and may fix the defective one with one of those kits - the sponge on the surround of one of them was pretty much ripped so we will see if it is repairable. If you do not hear any more from me on this issue, I guess my cheap Goldwoods are just fine.
01-25-18, 01:08 PM
Drop-in (almost) Woofer Upgrade
