Modding the Altec Lansing MX 5021 for dummies!!

Desecrator

INTRODUCTION

The Altec Lansing MX 5021 speakers have been here for a while. Tauted to be one of the best speakers in the 2.1 genus second only to the legendary Klipsch Promedia 2.1, the Altec still packs a punch when it comes to performance. Audiophile grade music and one need not spend an arm and a leg on the speakers!

Although the MX 5021 was launched at a staggering price of about 11k and thereabouts, there have been revisions in the motherboard, the crossover circuitry, the mid-woofers and sub-woofer design for the speakers which were launched post 2007. There’s also been a significant reduction in the price for which the speakers retailed at the time of launch and today! You can get a set for close to 6.5k (depending on where you’re located!).

There have been a couple of mods attempted on the MX 5021 by audio DIY enthusiasts around, floating on the web (Eg. Jimmy from Malaysia has put up an article on his blog; read it here: Jimmy’s Junkyard Blog Archive Inside Altec Lansing MX5021: Amplifier Mod , our own TE member Sangram has compiled an article which prompted me to go ahead with this mod! Both these mods have been attempted on the first-gen MX 5021.)

Most mods are inexpensive and would suggest replacing the stock OPAMPS and the stock capacitors which get along the way of the signals as they cause significant degradation thanks to the quality of the capacitors/OPAMPS used. Attempting the mods are pretty easy, provided you’ve touched a soldering iron before and have a li’l DIY intellect hidden within yourself! Awaken thyself monsieur!

Before we get started with the mods, let me be very clear with 2 things. Attempting the mod WILL void the warranty of the speakers (it’s going to be Rashi Peripherals ultimately, so think twice before you’re at it!

Dont hold me responsible for anything that might go wrong) and I shall not touch the hard-core electronic aspects of the mod being attempted.

?dOuBtFiRe? · #1 (**permalink**) By ?dOuBtFiRe? on 8 Mar 09, 07:35 PM

That is some nice Mod you been at.

Thanks a lot for sharing your knowledge to us.

FaH33m · #2 (**permalink**) By FaH33m on 8 Mar 09, 07:50 PM

been waiting for this ,truly a walk through for a n00b

really well written and illustrated with the pics.
good job Gunman !

looking forward to mod my MX 5021 in the future

dracul · #3 (**permalink**) By dracul on 8 Mar 09, 08:35 PM

great job gannu,you had tonns of patience...............

cranky · #4 (**permalink**) By cranky on 8 Mar 09, 09:20 PM

Nice pics, and a very handy guide, so that it can be easily tackled by noobs.

Components for interested guys can be bought from Digikey in one lot, and can be distributed locally (GO). Advise not to use locally available passives except the Thermax Polypropelene caps. Everything else will need to be brought in. The 5532 are easily availble but watch for fakes, and keep a chip or two handy over and above the three/four required.

Please use only the following caps (any one):

Nichicon KZ (the best possible)
Panasonic FC
Panasonic FM
Elna Silmic (less preferred)
Elna RFS (even less preferred)

I prefer the Panasonic FC, which is what me, SunnyBoi and Gannu (and Bikey, soon enough) used for the mods, all form my personal stash. FM is also good enough. They are not killingly expensive, and deliver adequate performance. You could go all out and get Black Gates but why would you have a MX5021 then?

Lastly Gannu the 15uF cap in your crossover drawing is 100% incorrect. The cap is either across both the woofers, or across the bottom woofer. It cannot be in series with both the woofers as it would result in a high-pass filter at about 500Hz, this is surely not the case. If you trace the circuit again it will most probably be in parallel with the lower woofer, to prevent two woofers from combing.

Good show, and glad you like the mods. Your soldering is pretty good too, so you won't have problems in the future.

hatter · #5 (**permalink**) By hatter on 9 Mar 09, 02:51 AM

Wonderful guide Gunman... that's the real geek stuff

Desecrator · #6 (**permalink**) By Desecrator on 9 Mar 09, 09:35 AM

Thanx for the appreciation guys!

Quote:

Originally Posted by sangram

Lastly Gannu the 15uF cap in your crossover drawing is 100% incorrect. The cap is either across both the woofers, or across the bottom woofer. It cannot be in series with both the woofers as it would result in a high-pass filter at about 500Hz, this is surely not the case. If you trace the circuit again it will most probably be in parallel with the lower woofer, to prevent two woofers from combing.

Oh! But AFAIK I traced it and double traced it! I shall do it tomorrow evening and post back.

Amey · #7 (**permalink**) By Amey on 9 Mar 09, 09:43 AM

Very well written guide Gannu

Congrats on succesful implementation of the mods too !

sarang · #8 (**permalink**) By sarang on 9 Mar 09, 09:49 AM

Congrats gannu, good job there.

Gotto hear it once.

WingZero · #9 (**permalink**) By WingZero on 9 Mar 09, 11:15 AM

Very detailed guide...u wer a dummy too earlier

...not anymore

Repped!. Will skim thru it later too wen warranty on my mx dies too.

vijaycool · #10 (**permalink**) By vijaycool on 9 Mar 09, 12:05 PM

Great tutorial

I am deciding between Edifier C3 or Altec lansing. Anyone auditioned these?. What could be the told cost of the components.
OT: Solderon is not the same quality as before. Last month i purchased solderon for 165 bucks and the heating coil gave up last week

i could not find spare coil anywhere in ritchie street.

cranky · #11 (**permalink**) By cranky on 9 Mar 09, 12:29 PM

There are a lot of fakes. My first iron lasted 8 years, the second is on its fourth year now (but not as heavily used). No problems so far, except the tips wear out much quicker nowadays.

@Gannu: Do keep the post updated once you've redrawn the schematic. The PCB tracks themselves point to the mistake. The coil is connected directly to the orange wire (top woofer +), the cap is connected from this joint to the overall ground (black wire from input). This is a classic second order filter. The two woofers are in series connection, without a secondary filter to prevent lobing. Not the best arrangement, I would make a small 22uF bipolar cap (you can use two of the 47uF caps I sent in a back-to-back arrangement) and connect it in parallel to the bottom woofer. This is obviously inexact, but it would help increase the focus, at the expense of some overall volume (slight reduction).

WingZero · #12 (**permalink**) By WingZero on 9 Mar 09, 12:55 PM

Quote:

Originally Posted by sangram

There are a lot of fakes. My first iron lasted 8 years, the second is on its fourth year now (but not as heavily used). No problems so far, except the tips wear out much quicker nowadays.

@Gannu: Do keep the post updated once you've redrawn the schematic. The PCB tracks themselves point to the mistake. The coil is connected directly to the orange wire (top woofer +), the cap is connected from this joint to the overall ground (black wire from input). This is a classic second order filter. The two woofers are in series connection, without a secondary filter to prevent lobing. Not the best arrangement, I would make a small 22uF bipolar cap (you can use two of the 47uF caps I sent in a back-to-back arrangement) and connect it in parallel to the bottom woofer. This is obviously inexact, but it would help increase the focus, at the expense of some overall volume (slight reduction).

Skimmd thru ya post and i simply didnt get a word u said.

.

Desecrator · #13 (**permalink**) By Desecrator on 9 Mar 09, 01:28 PM

^

Quote:

Originally Posted by sangram

@Gannu: Do keep the post updated once you've redrawn the schematic. The PCB tracks themselves point to the mistake. The coil is connected directly to the orange wire (top woofer +), the cap is connected from this joint to the overall ground (black wire from input). This is a classic second order filter. The two woofers are in series connection, without a secondary filter to prevent lobing. Not the best arrangement, I would make a small 22uF bipolar cap (you can use two of the 47uF caps I sent in a back-to-back arrangement) and connect it in parallel to the bottom woofer. This is obviously inexact, but it would help increase the focus, at the expense of some overall volume (slight reduction).

Oh. Never mind the volume reduction. I dont crank up the volumes anyway. If it helps in SQ, I'll give a shot. U meant 2 47uF caps in series and then ||el to the bottom mid-woofer right?

Shall check it up today evening and put up a new schematic and ping you!

Meanwhile I presume u did a rewiring to the mid-woofers as well?

Was it using the same ones that u'd used for the subwoofer? If thats the case I've half-a-metre 60-taar wala wire left over here. Can use that.

And why not connect the only series wire directly from one midwoofer to the other instead of taking it all the way to the PCB and soldering it there?

Does that help in any case? Was just curious.

@vijaycool: Its Soldron; solderon could be a fake. I also saw a Soldon at the shop. Exactly the same packaging.

Like Sangram rightly said, there're lots of fakes which retail for like less than 20 bucks than the price of the original stuff.

This's the website: Soldron Soldering and Desoldering Equipment India from Vimla Engineering

cranky · #14 (**permalink**) By cranky on 9 Mar 09, 01:46 PM

@WingZero: I did not expect everybody to understand it, the post was not even meant for you, so it's totally cool if you didn't understand it.

Quote:

Originally Posted by Gunman

U meant 2 47uF caps in series and then ||el to the bottom mid-woofer right?

Bang on! Solder the negative terminals together, so that only the positive leads are exposed. This helps one cap protect the other from reverse voltages.

Quote:

Meanwhile I presume u did a rewiring to the mid-woofers as well?

No.

Quote:

And why not connect the only series wire directly from one midwoofer to the other instead of taking it all the way to the PCB and soldering it there?

Because the guy who does the wiring may be different from the guy who knocks it together? There is really no other reason, it might just help in assembly line manufacturing, and avoids error by someone getting the series connection wrong. It will not help or harm much. The wire carries small currents, so I doubt it will help to rewire. The terminals are also very small and may get damaged with a lot of heat, so watch it.

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Modding the Altec Lansing MX 5021 for dummies!! Discussion under Guides and Tutorials, part of the Work in Progress category on TechEnclave; INTRODUCTION The Altec Lansing MX 5021 speakers have been here for a while. Tauted to be one of the best ...