LX470 Mark Levinson front door speakers: conflicting info on OHMs

[jumptrader]

Hi,

I'm about to replace the front door speakers in my 2003 LX470 (the floor, 6.5" speakers), and I'm seeing sources say anywhere between 2-3 ohms:
Mark Levinson speakers

To 6.9 ohms:
Front Speakers?

For those who have replaced these speakers, which speakers did you end up with and what the ohms reading?

Thank you!

 

[jumptrader]

Update:
Some to Crutchfield, their 'advisor' said the company's note suggested a 7.5 ohm impedance. Nothing no deeper than 2.69". An ideal operating range of 25-30W.

Will likely go with this unit:
MTX Audio RoadThunder Extreme Midbass Speaker - RTX658
MTX RTX658 6.5" RoadThunder Car Mid-Bass Driver
* 8 ohm
* 2 11/16" deep (2.69")


Will update as I continue with the build.

 

[johsti]

Why are you replacing the front speakers? Typically a refoam kit will bring them back to life.

 

[jumptrader]

Why are you replacing the front speakers? Typically a refoam kit will bring them back to life.

I would love to but I don't trust my skills.. I notice you're in SJ! Do you by chance know any audio folks in the bay area that might be able to help with refoam?

 

[johsti]

I would love to but I don't trust my skills.. I notice you're in SJ! Do you by chance know any audio folks in the bay area that might be able to help with refoam?

I don't know anyone who does it professionally, but I plan to do my own when the foam surrounds on my speakers fail. This place carries replacement foam surrounds. Speaker Foam Edge Repair Replacement Kit, Toyota, Lexus, JBL, Levinson 6" Speakers, FSK-6bt

 

[68W65D]

I would love to but I don't trust my skills.. I notice you're in SJ! Do you by chance know any audio folks in the bay area that might be able to help with refoam?

I did the foam repair on my subwoofer and it made it sound good as new. The instructions were very clear. I was a bit anal about the whole thing and it took me around 4 hours to do the whole project.

If anything ever happens to my door speakers, I wouldn't hesitate at all to do it again.

Besides, worse case scenario if you totally botch the job, you can then get a new speaker.

 

[LXColorado]

I did the foam repair on my subwoofer and it made it sound good as new. The instructions were very clear. I was a bit anal about the whole thing and it took me around 4 hours to do the whole project.

If anything ever happens to my door speakers, I wouldn't hesitate at all to do it again.

Besides, worse case scenario if you totally botch the job, you can then get a new speaker.

Which kit did you use?

 

[68W65D]

Which kit did you use?

I used the exact same on e linked by johsti above.
Worked great. Even better, it came with two so if you screw up, you have a spare.

 

[jumptrader]

Update:
Some to Crutchfield, their 'advisor' said the company's note suggested a 7.5 ohm impedance. Nothing no deeper than 2.69". An ideal operating range of 25-30W.

Will likely go with this unit:
MTX Audio RoadThunder Extreme Midbass Speaker - RTX658
MTX RTX658 6.5" RoadThunder Car Mid-Bass Driver
* 8 ohm
* 2 11/16" deep (2.69")


Will update as I continue with the build.

Update:

1. Used this link to remove the door panel
Door panel removal process

2. Ended up replacing the speakers this past weekend. So far so good, had to drill in new speaker mount holes but from what I can tell, the quality of the MTX speakers looks about 5x better than than ML speakers. I did notice some slight rusting on the metal cylinder part of the ML's driver - it probably would have worked if I simply re-coned the speakers but figured on a 14-year old vehicle it could use a new replacement.

Technical level: 3/10 (still quite new to work on the truck as well)
Time: 5 hours to do both doors - hardest parts were figuring out how to secure the speaker mount under the drill press for the new holes

 

[dperque]

FWIW, I just replaced my ML '05 LX470 DS speaker with Infinity 6522ix and it fit pretty well. The confusing part came with this discussion around depth as my speakers are not in their own enclosure (they just use the door as it's enclosure). So I could have used any 6.5" speaker for this application.
I'm a tad disappointed in the overall sound - it sounds more or less the same (low bass response) because the speaker lacks it's own enclosure. But I will say that my factory speaker had become quite brittle and the foam surround basically fell apart in my hands. So I had to replace my grill cloth anyway so overall glad I replaced the speaker, but adding an amplified subwoofer has been a much bigger improvement overall to the 'experience'.
So basically I would say unless you're replacing your grill cloth or have a 'blown/non-functioning' speaker, I don't see this as a priority project.

 

[John Young]

Just to document, here is a measurement of ML front passenger speaker out of a 2001 LX470:

Not good when you can see through the cone. Off to Sharjah to see if I can get replacements for all four.

 

[MuseChaser]

I would love to but I don't trust my skills.. I notice you're in SJ! Do you by chance know any audio folks in the bay area that might be able to help with refoam?

It's time to start trusting your skills. I'd never done any mechanical speaker repair work ever, but my Levinson sub was rotted and I ws not about to spend close to $600 on replacing the unit. One $18 surround repair kit and two hours later (most of which was waiting for glue to dry), the sub was good as new, if not better. Watch the (boring) instructional video by Simply Speakers, order the kit, and git'er done. You can NOT mess it up..the speaker pretty much self-centers, and if you get a litle extra glue here and there and it doesn't look pretty, it doesn't matter. Do IT!

The Levinson system is very much an integrated, tailored set of very specific components, and swapping in other drivers w/ different response and impedance curves and phase characteristics would almost certainly be to the detriment of the sound as a whole, not to mention a lot more expensive. Trust me, you CAN refoam your speakers, and you should.

 

[MuseChaser]

Just to document, here is a measurement of ML front passenger speaker out of a 2001 LX470:View attachment 1764728
Not good when you can see through the cone. Off to Sharjah to see if I can get replacements for all four.

A simple measurement of reistance across a driver's terminal doesn't tell you much; speakers have a resistance curve that varies a LOT dependent upon frequency. Refoam your speaker; you'll be happier with the sound AND your wallet will be thicker. Have you seen any threads where someone replaced functioning ML door speakers with something "better" and liked the results? Me neither.

 

[toyotaspeed90]

Just to document, here is a measurement of ML front passenger speaker out of a 2001 LX470:View attachment 1764728
Not good when you can see through the cone. Off to Sharjah to see if I can get replacements for all four.

I've seen this discussion of resistance over and over.... I think many people either don't understand how stereos, and impedance, work or tend to forget.

The speaker you show is only 1 from that channel, but I'm willing to bet theres a tweeter somewhere that is tied to that same channel.

When 2 speakers are wired together you have to choose whether to run them in series or parallel- both the power out from the amp and the impedance of the channel are affected.

As resistance halves, power double. As resistance doubles, power halves.

Meaning - an amplifier at 4 ohms 100w will put out 50w at 8 ohm and 200w at 2 ohms.

The problem with this, however, is most apps aren't actually 2 or 1 ohm stable (unless you get a quality amplifier built to do that - your run of the mill big box store amplifier is not).

So, shouldn't be checking resistance of the single speaker unless you plan to replace only those speakers and wire them exactly the same as factory yo both the amp and other speakers.

Meaning - if you check resistance of the front right channel at the amplifier and it registers 4 ohm - you can eliminate 'all' speakers on the front right channel and just install a single 4 ohm speaker. Or two 2 ohm speakers in series, or two 8 ohm speakers in parallel.

You could also throw in a 6 or 8 ohm set as well - which will reduce the output (and is ''safer" on the amp).

If you change the overall resistance of the front (increase resistance) you should do the same to the rear channels. The sub is probably separate can be left alone or handled slightly different.


Or you can just buy an aftermarket head unit (if you don't have integrated climate controls) and run whatever you want and the HU is capable of.

 

[John Young]

(Part 1)

Thanks MC, I was coming to the same conclusion myself. And I've decided to try to repair the existing ML speakers.

Living in the Middle East it is not as easy as ordering off of amazon to get things like replacement foam rings for speakers. So I decided to find a 'field expedient'. In this case, very thin goat skin coated on one side with gold lame' foil. This came with a bunch of other leather odds and ends that I bought by the kilo a month or two back to play around with with.

Here's the existing ML speaker (I did not have to clean out the rim--it was simply gone!):

Here's the thin goat leather:

I used bowls of various sizes to create the outlines to cut against.

The back size of the goat skin is black and a good gluing surface. I used PVA glue which works well for leather and fabrics and stays flexible.

(Part 2)

I had to wait until the first glue joint is solid before I could glue down the edges. The trim ring has a keyway, BTW. Here is the reassembled ML speaker:

It seems quite flexible. Maybe the speaker won't have full travel, but I tend to play music softly anyways. I'm going to wait a couple of hours before putting it back in the truck and see how it plays, but so far so good!

Edit: here it is installed:

Midrange seems just fine to my ear now! I'm sure I reduced the fidelity with my goat leather ring, but I kind of like the idea of keeping it now! The driver's side speaker seems ok, but the passenger rear mid-range also is toast. I may try re-doing that one too. Although I really should use foam rings, not goat leather! It is sort of a thin parchment--very flexible. I wonder what Mark Levinson would think of it...

 

[John Young]

I've seen this discussion of resistance over and over.... I think many people either don't understand how stereos, and impedance, work or tend to forget.

The speaker you show is only 1 from that channel, but I'm willing to bet theres a tweeter somewhere that is tied to that same channel.

Quite true. There are actually three speakers in the front door of my 2001 LX470. Near as I can tell the other two speakers are fine. I'd expect them to have a crossover, but I have not pulled the wiring from the door to check that out. Mostly I just wanted to see if I can get some basic sound coming out, if for nothing else to check that the ML amp is functional.

Edit:

I've been thinking about the resistance measurement I made of 7.8 ohms. Yes, this is off because we actually want impedance, not resistance, but I did a little searching and found that for home audio purposes you can estimate impedance by measuring resistance and adding 15%:

"In the case of a cone driver, like woofers and instrument speakers, the situation is simple and the nominal value can be found by an ohm meter test and applying a simple formula ...

Nominal Impedance = R plus 15% - where R is the DC resistance in ohms"​

Speaker Failure Analysis

So a measured resistance of 7.9 ohms would imply about 9 ohms impedance for this particular ML speaker. So I'd think that buying an aftermarket 8 ohm speaker ought to work pretty well with a stock ML amp. This speaker is out of a 2001 LX, BTW. Maybe they changed speakers over the years....?

 

[MuseChaser]

John Young..

First, congratulations on your "MacGuyver-esque" repair of your speaker. Goatskin leather is a lot better than nothing! The foam surround has two purposes; one is keeping the voice coil centered around (or inside) the speaker magnet so it doesn't rub, and you can (and most likely did) accomplish that with your repair. The other thing it does is act like the speaker cone's suspension system, giving it a mechanical reason to return to its "neutral" position as well as an electrical reason (provided by the coil/magnet interface). The foam surrounds of these speakers are fairly compliant (meaning, not stiff), so they don't apply a lot of force to return the speakers to "neutral" position, but they do apply some while allowing probably greater excursion than your goat-skin solution allows. If you want to experiment further (and are SURE you can't get the proper surrounds shipped....to be honest, in this day and age, I'm surprised there's not SOME way to get them to you), you may be better served using your goatskin solutions as a template and trying to find some thin rubber (bicycle inner tube? surgical/rubber hose split down the middle? Dunno,.. just thinking out loud) to use. Something compliant with lots of stretch, but that wants to return to it's original "at-rest" shape.

Second... the "measured resistance plus 15%" isn't about sound quality, it's about making sure your speaker and amp don't melt each other. As the article you linked stated, nominal impedance just means the lowest impedance the speaker will present to an amp at any given frequency. The catch is, the speaker/amp interface is almost constantly working at a huge range of frequencies simulatneously, and speaker systems (woofer/midrange/tweeter and associated crossovers from simple first-order networks to complex second, third, or fourth Linkwitz, Butterworth, or other configurations, sometimes including Zobel networks for impedance smoothing, attenuation circuits to match driver efficiency.... it's a lot of fun, but it's NOT as simple as choosing any specific nominal impedance and dropping in a driver that matches that spec) are designed taking each driver's characterstics into account. A driver's characteristics can NOT be summed up with something as simple as a nominal impedance figure.

The Levinson system is designed as a carefully integrated system, and sounds great; to be honest, I was blown away with ours after I repaired the sub. I'm an audio snob, part-time recording engineer, hobbyist speaker designer, and full-time professional acoustic musician. The Levinson system is truly the first time I've ever sat in a car and WANTED to turn the volume up because it sounded so natural.. not boomy, not screechy... just sounded like real INSTRUMENTS. The vehicular environment, at least for me, makes searching for the ultimate in realistic audio reproduction a total waste of time. If you want to show off how loud your system will play or make your girlfriend's hair puff w/ your subwoofers, or make your eardrums bleed with mind-ruining high end, this ain't the system for you. If you like to listen to about as natural, realistic a sound as you're going to find in an automobile, stick with the system as designed and do what you're doing... repair the original equipment.

And now, I shall step off my soapbox and return to the much more important job of vanquishing micheladas and tequila.

 

[John Young]

Hi there MC,
Thanks for your post. I think, oddly, that I share all your views. I've gone to some trouble to keep the existing ML/Nav system by using a BT45-TOY to get my desired audio (bluetooth and AUX) into the system. I've also concluded that it is going to be tough to find exact replacements of the ML speakers, which If I am counting them correctly, include 6 in the front, 2 in the rear passenger doors, and the subwoofer in the back, for a total of 9 speakers. As of this evening, I tested the front 6 speakers with a tone generator and near as I can tell all 6 are now functional, but I do need to take off the driver front door panel to check on the condition of the 6 inch speaker--I suspect its ring probably needs replacement too. The next step after that is to figure out why I get no sound at all out of the rear right passenger door. I kind of hope it is the amplifier because I mistakenly bought a replacement ML stock amp from a local breaker for about 80 bucks, and I'd like to actually use it!

So, in sum, I'm hoping to restore the existing ML system, rather than replacing it. I enjoy restoration much more than substituting modern components. Also, that way I don't have to worry about crossovers and so forth--I'm just fixing what is there.

I enjoyed your soapbox. Thank you. I still think that the ML front 6 inch speakers have 8 ohms impedance, BTW!

 

[Bull Moose 100]

John Young..

First, congratulations on your "MacGuyver-esque" repair of your speaker. Goatskin leather is a lot better than nothing! The foam surround has ......
......
......

And now, I shall step off my soapbox and return to the much more important job of vanquishing micheladas and tequila.

I agree with you that simply repairing the surrounds will make the system sound great again, but what are your thoughts on installing new high quality 2 or 4 ohm speakers and running them off an aftermarket amp that uses the ML amp speaker outputs as high level inputs?

Hooking up the new amps using their high level inputs will add some distortion, but the higher quality speakers will create less distortion when pushed to higher listening volumes.

I have the entire interior of my truck taken out right now and have installed dynamat and extra carpet padding, but I am being held up as I hesitate between repairing the speakers or doing new speakers, sub, and amps....

 

[Bull Moose 100]

I seem to have trouble hearing and understanding the lyrics of songs. When ever I have completely replaced a stereo in the past, I have been able to hear the lyrics accurately.