SDC upgrade from 603 suggestions?

[MichaelJoly]

Experiments show correcting diaphragm set-back will remove diaphragm-to-wire mesh "tunnel resonance", improve transient response detail and reduce edge diffraction coloration. Enlarging the capsule back chamber vents will reduce HF lift - a reverse application of the technique Neumann used to make the KM-184 brighter than the KM-84 (both use the same capsule).

These two modifications are more effective than backplate hole modification at producing a more pleasing capsule that conforms more closely to the designer's intent (confirmed in private conversation) - which was to make a copy of the KM-84 capsule, an intent not successfully implemented by MXL's vendor.

 

[noisedude]

so why did Harvey get banned?...

We're absolutely not raking over that again.

The site is under different ownership now and in the absence of clear direction coming from the top we will continue to deal with each situation on its merits.

I agree 100% with mshilarious' assessment of this thread.

???????????????????????????????????//

Where have I been?

Is the world spinning backwards?

It happened about four years ago and was, if I remember rightly, for 24 hours.


That will be the end of this discussion, thanks, this thread won't turn into a tedious spamversation. Who has an opinion on what santiu should do?

 

[Marik]

...I understand that he'll be doing both an electronic and capsule modification...

Yep you are right, here is what I am doing:

Electronics:
The front end of this mic is build around low-noise 2SK170, which is IMO one of the most excellent FETs for mics, both sonically and for its electrical characteristics. It is however, also one of the most misused devices and needs completely different operational points in order to start shining.
I completely change the bias points and as a result it dramatically increases headroom, as well as greatly improves sonics.
As a result of improved headroom I am able to increase the DC/DC converter voltage for capsule bias, which gives higher output.
I also do tricks in the output stage, which originally could not drive long cables without distortions, which were responsible for that brittle sound. Now the distortions are dramatically reduced and the sound is quite homogenous.

Capsule:
One of my favorite SDC mics is KM-84 for its rounded top and full low end.
As M. Joly finally admitted, the copy of the KM-84 capsule was not successfull (his words are: "the copy of the KM-84 capsule, an intent not successfully implemented by MXL's vendor"), and I don't believe the microphone body crippling is the answer, as it does not changes things drastically, although the change of acoustic labyrinth parameters is the right direction.

The MXL603 capsule is a two chamber design, with questionable design parameters, which result in lack of bass, shrill and brittle sound, and lousy cardioid pattern.
I turn it into three chamber design--that's right, before it had only one plastic piece behind the backplate and now there are two, for completely different time delay parameters, with careful selection of the material, spacers, and hole diameters.
The plastic time delay piece in the original capsule is molded and shrunk and you can see the air trapped bubbles in it.
Instead of molding I machine the pieces on my high precision lathe, which has digital readouts with 1 micron resolution eek:) and all the spacers are incorporated into the pieces, so the tolerances are extremely tight.

I machine off the front of the capsule to reduce front cavity resonances. I also replace the grill mesh with more rigid one and with much more open area, which contributes transparency. As a result of all those modifications now the top is nicely rounded, and bass is nice and deep in existing body.

Out of couple dozens customers who already owns the modified mics, EVERYONE says that the sound is very close to KM-84 and the cardioid polar pattern is nice and tight.

Here are a couple tracks of original capsule and modified. Please note, both are on the same modified body, so you hear only capsule differences:

http://home.comcast.net/~markfuksman/MXLStockCap.wav

http://home.comcast.net/~markfuksman/MXLModdedCap.wav

Best, M

 

[santiu]

Wow, those are some impressive mods... i might just have to get that done one day.

I machine the pieces on my high precision lathe, which has digital readouts with 1 micron resolution eek:) and all the spacers are incorporated into the pieces, so the tolerances are extremely tight.

While i'm sure your a great machinist, there's no way you're getting these to within anywhere near 1 micron tolerances. At work ordering parts even just hitting 5 tenths (0.0005" or 13 microns) on a diameter ends up costing several thousand of dollars. I can't imagine you'd be able to do better for cheaper, or have the metrology to inspect such a tolerance.... don't mean to knock you. I dig your work, just saying, that's a bit of a misleading statement.

 

[Gidge]

We're absolutely not raking over that again.

The site is under different ownership now and in the absence of clear direction coming from the top we will continue to deal with each situation on its merits.

I agree 100% with mshilarious' assessment of this thread.


It happened about four years ago and was, if I remember rightly, for 24 hours.


That will be the end of this discussion, thanks, this thread won't turn into a tedious spamversation. Who has an opinion on what santiu should do?

I was just seeking a clearer explanation of the rules concerning dealer spam/advertisements, so quit being a dick...

the board has a function that allows users to help moderators by reporting posts..are you saying we should not use that?

 

[noisedude]

I was just seeking a clearer explanation of the rules concerning dealer spam/advertisements, so quit being a dick...

the board has a function that allows users to help moderators by reporting posts..are you saying we should not use that?

If you want to have this discussion, start a thread in Site Feedback. Leave this one on topic, please.

Reports were received relating to this thread and two moderators have told you the position. Move on, or take it elsewhere on the site if this is a burning issue for you.

 

[Marik]

While i'm sure your a great machinist, there's no way you're getting these to within anywhere near 1 micron tolerances. At work ordering parts even just hitting 5 tenths (0.0005" or 13 microns) on a diameter ends up costing several thousand of dollars. I can't imagine you'd be able to do better for cheaper, or have the metrology to inspect such a tolerance.... don't mean to knock you. I dig your work, just saying, that's a bit of a misleading statement.

Thanks for the great comment! Indeed, on diameter it is very hard to get this kind of tolerances, and also very much depends on the material.
However, machining in spacers on a compound slide in the material I am using is very different and is considerably easier. I don't claim 1um tolerance (it was resolution ) and the thickness inspection is easy--Mitutoyo indicator with 0.001mm (one micron) resolution on a granite plate. Anything out of wack more than 10 micron goes into the garbage bin.

BTW, if you look at the original plastic pieces--they are mostly shrunk, warped, or both together, with uneveness seen with eyes.

Best, M

 

[noisedude]

Thanks for the great comment! Indeed, on diameter it is very hard to get this kind of tolerances, and also very much depends on the material.
However, machining in spacers on a compound slide in the material I am using is very different and is considerably easier. I don't claim 1um tolerance (it was resolution ) and the thickness inspection is easy--Mitutoyo indicator with 0.001mm (one micron) resolution on a granite plate. Anything out of wack more than 10 micron goes into the garbage bin.

BTW, if you look at the original plastic pieces--they are mostly shrunk, warped, or both together, with uneveness seen with eyes.

Best, M

Hey Marik, have you ever posted photos of these sorts of mods? I'd quite like to see what goes on in terms of changing the insides of a microphone, both in terms of the electronics and the physical parts.

I have to admit that I'm easily impressed by any of the guys who mod stuff because I'm the sort of bloke that reads the warning not to take the case off something and obeys it without fail.

 

[b3groover]

Marik's capsule mod is quite impressive. I have three pair of MXL 603s mics. Two pair are mod'd with the capacitor swap and the other pair is mod'd with the Royer tube mod. I've been using the Royer mod'd pair as overheads and have been very pleased with the results. The Royer mod drastically reduces that metallic high end.

Marik's capsule mod, however, completely removes any remaining traces of the Chinese high-end disease that so many of these mics suffer from. It is almost ribbon-like in nature. Very natural, open, and balanced.

It also sounds great on the capacitor mod'd models.

 

[tdukex]

We're absolutely not raking over that again.

The site is under different ownership now and in the absence of clear direction coming from the top we will continue to deal with each situation on its merits.

I agree 100% with mshilarious' assessment of this thread.


It happened about four years ago and was, if I remember rightly, for 24 hours.


That will be the end of this discussion, thanks, this thread won't turn into a tedious spamversation. Who has an opinion on what santiu should do?

Wow, give a fellow just a little bit of power, and watch what he becomes.

Sorry, santiu, I think you should mod the 603s before forking out considerably more for other mics. I have an older 603 and an MK012. They sound very similar to me (and to Harvey as well--at least the older 603s), and I don't have a problem with too little bass or either of them being too bright on my acou guits.

However, If I had the money to spare I would certainly be interested in the 930's.

 

[Gidge]

Wow, give a fellow just a little bit of power, and watch what he becomes.

lets try and stay on topic son...

 

[dkelley]

I recommend better mics if you can afford them...

Hi there,

I'd say avoid those 603 mics. I know I'm saying bad things probably, and this is homerecording.com so budget is likely limited (I totally understand, I'm trying to sell my RCA BK5A ribbon from the 50s right now, can't afford an expensive-ish specialty mic any more, need more bread and butter gear in these hard times).

I owned similar mics. I admit they may not be the same, (apex 180) but I hated them. from a distance and with dark cymbals and a light player they sounded great. but for almost every "normal" drummer they sucked. They're gone now. I believe but could be wrong that they're basically the same as the mxl 603. hard to recall exactly, I used to know... there were two chinese manufacturers of cheap pencil sdc mics when both of those came out and I can't recall if the 603 was the same design (screw-in different capsules and narrow body) or if the 603 was in some way better.

Anyway, either way, what you're describing sounds exactly like apex 180 mics (especially in cardoid mode, in omni they're slightly better... but still...).

IF you can afford it, you will get far better results overall and much more versatile mics out of the following models (I know, much more expensive but still relatively cheap for entirely pro-quality mics):
- AKG C535EB
- SHURE KSM109
- AUDIO TECHNICA AT2020 or AT2021 (same cap/electronics, different body, both Small Diaphram Condensors but AT2020 looks like a LDC)

the audio technica is getting into cheap territory but very well built and versatile mic. you can buy the 2020/2021 pair (obviously not matched but still useful) as a package often, work well as an odd looking pair of overheads but I wouldn't say "matched" since subtle tone change between body designs among other manufacturing randomness without being a stereo pair of course.

the Shures are great and a pair might be $350 to $450. AKGs are even better IMHO (can make great vocal mics espc for female singers and can even work as live handheld vocal mics if you have phantom power) but another couple hundred for a pair probably (these are new prices off the top of my head).

You get what you pay for, if you can't afford those then maybe get the 603s modded.

I have YET to hear a modded mic with before/after a/b recordings that didn't still sound very similar to the original tone, albeit with obvious improvements. Generally the way a mic improves is in lowered distortion, more linear frequency response and sometimes off axis response, and sometimes a subtle improvement in bass (totally generalizing on mic mods here, not 603 specific or directly related to the mods discussed here). If you dislike the tone of your 603s, you may well dislike them after spending lots of money on them since they will still have the same capsule which is designed to have a very bright top end, no modding (other than stuffing the mic into a few layers of socks LoL) will reduce the overall brightness of the mics. You might want that, but it sounds maybe like you don't. I think the mod description sounds great and much more extravegant than most mic mods (machining body?? wow, kewl stuff, seriously I'm very impressed!) but it will STILL be a bright mic without some dramatic eq and maybe some luck.

But if you sell them and use that money plus the mod money you were going to use and buy a pair of mics listed above (preferably the shures or akgs for a quite dramatic improvement, the ats are a more subtle but still definite improvement imho), you'll get great mileage.

You'll also be using mics that have a bigger brand name behind them - something that is satisfying when you pull them out in front of musicians ("oooh, akg mics! these are great, all the big studios have 'em") LoL

Cheers,
Don

 

[santiu]

Don, thanks for the advice. How do you think the beyer MC930's stack up against the AKG C535EB's?

I'm thinking right now to do the simple mod of replacing some capacitors on the 603s myself, and just live with them for a bit longer while i save up for the MC930s.

 

[dkelley]

by the way, I know some engineers do use mxl 603 mics professionally, even apex 180 mics. I'm just giving recommendations. I strongly feel that what I'm suggesting will be a more impressive sound improvement to you.

I like obvious differences when I hear someone complaining about brightness ,muddiness etc in their recordings. I like to suggest things that will really dramatically help.

In no way am I dissing the mods discussed here and I'm blown away with the type of mod being discussed.

just my two cents worth good luck and have fun!!

 

[MichaelJoly]

Lots of sage advice clipped before this point...

...If you dislike the tone of your 603s, you may well dislike them after spending lots of money on them since they will still have the same capsule which is designed to have a very bright top end, no modding (other than stuffing the mic into a few layers of socks LoL) will reduce the overall brightness of the mics.

I wanted to address the "designer's intent" and the effectiveness of a particular modification.

First, in the past two weeks I had a phone conversation with the designer of the MXL 603 (an outside consulting specialist, not an MXL employee) who told me his intent was to design a copy of the KM-84 capsule. The rigor of his design was lost during MXL's bid process and the capsule was manufactured with several changes that make it unlike the KM-84 design. So the 603 was not designed to be bright, it just ended up that way when executed.

Second, the principle acoustic mechanism that causes brightness in the MXL 603 is insufficient capsule back chamber venting. During the development of the KM-184, Neumann found body vent area affects on-axis high frequency response. The bright KM-184 sound was created by reducing body vent area of the KM-84 capsule - same capsule used in both mics, only the body area venting changed. Enlarging the 603 body venting has an effect of similar magnitude in reverse - it removes on-axis HF boost.

So in the case of the MXL 603 - it was not "designed" to be bright, it ended up that way, and can have its HF response attenuated through a modification to the body vent area that will make it conform more closely to the designer's intent - a KM-84 copy. There are other demonstrable improvements as well but I wanted to focus on this one issue of brightness.

 

[Whoopysnorp]

Consider the Peluso CEMC6. I upgraded from the 603s to a pair of those and have been very pleased so far. When I A/Bed them on drums I found that the Pelusos were tickling some areas in the middle of the frequency spectrum that I wasn't getting with the 603s...this confers a certain 'fullness' that is lacking in the MXLs. Top end response is more even as well. They can be had around $600 a pair, and are hand-built in the USA by a dude. I like that sort of thing.

 

[rmaier]

I thought all of the Peluso capsules were made in China and tuned by John Peluso in the States?

 

[Whoopysnorp]

Hm, you may be right about that. My mistake if true.

 

[MichaelJoly]

"Ultimate MXL 603 Mod" vs. Neumann KM 184 as drum OH

Just got some drum OH sound files back from Alan Dossett.

Separate takes, slightly different mic positioning in each take (he's a monster drummer, not an engineer). So just ignore the stereo separation difference and concentrate on the bass extension, mid range impact and cymbal purity. Alan says the "Ultimate MXL 603 mod" kicks major booty.

SOUND FILE: Neumann KM-184 drum OH pair
SOUND FILE: OktavaMod "Ultimate MXL 603 Mod"

 

[mshilarious]

Again I will ask vendors to refrain from sales talk on the board. Discussion of the technical details of your products or services is acceptable insofar as it enables DIY types to enjoy the benefit of your knowledge and contributes to the general understanding of the different characteristics of microphones.