Replacing driver screws with brass screws


There was some discussion about this on Millercarbon's thread about the Moab speakers, and I wanted to pursue the subject further without interfering with his thread.
As I stated there, I have heard about this practice for quite a few years, but never tried it because it seemed like one of those lunatic fringe ideas; and even though I actually really enjoy trying tweaks, and have found many of them effective, I just was not prepared for what this one did for the music coming out of my speakers. 
Specifically, it improved the detail in ambient trails, focus in general, complex harmonics in voices and stringed instruments, and instrumental separation. It is not subtle, and it is immediately noticeable.
So, I am curious to know how many of you out there have tried this, and what your experience has been.
Thanks, John  
D3017ce8 5648 4de7 9525 e7de44490aa9roxy54
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it improved the detail in ambient trails, focus in general, complex harmonics in voices and stringed instruments, and instrumental separation. It is not subtle, and it is immediately noticeable.
Have you measured the speakers before and after to make sure its not your imagination?  Don't be so silly. 
And now John you see how it is and how people earn their place on the list. Its a perfectly valid discussion to have. If originality was required the worst offenders would be the first to go. Couldn’t think an original thought if their life depended on it.

The sounds we are most concerned with, the cues that tell us which instrument, and where, and how big a space, these are supremely fine details. No one even comes close to measuring, yet we hear them easily.

When you dig into the details of speaker construction, or even just hold different drivers in your hands and look at them, its apparent the better ones put a good deal of time and money into controlling really small vibrations.

Its not just the obvious stuff like thick or braced baffles, or even less obvious stuff like laminates and composites. Even little details like the speaker spider and surround are designed to be both stiff and highly damped.
Which makes it all the more strange that having done all this more often than not they mount these engineered marvels to their sweated over design cabinets with ordinary screws and gaskets.

The way I see it the improvement you’re hearing isn’t all that surprising to me. The way I see it everything else is engineered better than the interface where the driver fastens to the cabinet. This is why mine were improved so much with fO.q TA-102 tape, and why you heard so much improvement with brass screws.

Best of all you described the main things I was looking to hear, "improved the detail in ambient trails, focus in general, complex harmonics in voices and stringed instruments, and instrumental separation. It is not subtle, and it is immediately noticeable." Reason I say best of all is because when I tried something like this many years ago I heard a similar improvement but was put off by it giving too much emphasis to brass instruments. Sax, cymbals, horns sounded a little too brassy.

But that was a very long time ago, and a very different situation. Now I just need to find the right type brass screws for my Moabs. Thanks!
Thanks squeak. I read those threads just now. I guess as expected, some believers, some doubters. Very surprised to see Peter from PBN saying it could make no difference. He's a smart guy, but he's dead wrong in this case. 
Millercarbon,
Yes, all small things matter, and some matter a lot. I am now going to experiment with gasket material. I looked up the material that you are using...ouch! Pretty expensive.
The drivers need to be mounted securely for sure. Loose screws/drivers not firmly mounted will negatively affect exactly the things the op mentioned. As will defective gaskets. Most screws will need tightening from time to time in that the vibrations from drivers naturally tend to loosen them over time. So don’t forget to make sure drivers are tightly attached from time to time. This surely will have a negative effect and I would expect to a much greater degree than the metal used in properly applied screws could.
Hi Mapman,
That is the reason that I was so surprised at the difference. I tighten my drivers on a regular basis, and had just done so 2 weeks ago, so they were tight before I changed to the brass.
Have you measured the speakers before and after to make sure its not your imagination? Don't be so silly.
+1 this is just "fuser" snake oil stuff from the same voodooists, SR are probably about to release cryo'd brass fixing screws for $500 a set.  

Cheers George
Well brass screws are not expensive so if someone thinks they are worth it not a big deal.

If Uber expensive audiophile brass screws from Synergistic or others suddenly start popping up it would look very suspicious.

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This reminded me I have not checked the wing nuts on my Ohm Walsh driver boards in awhile. They were still pretty tight but one or two had a slight give. Now they are tight for sure and I think I hear a difference.

Or do I? I have a pretty active imagination sometimes.

I can say for sure it sounds darn good right now which is usually the case.
georgehifi,
Congrats! I’m so glad that you posted what you did and once again proved how much you don’t know. Appropriate that you should find common ground with kenjit, the biggest troll on audiogon. 
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A staple of all things brass and bronze , mostly for wooden boatbuilder nuts Jamestown Distributors. 
Of course, nothing eats detail like a non pistonic driver.... or a super big baffle mechanical averaging machine.....
Very surprised to see Peter from PBN saying it could make no difference.

If that is indeed what he said then it is no surprise to me. None at all. What he said was it "could" make no difference. Read carefully what that means is he ASSUMES and has NEVER TRIED.  

That tape is very expensive per square foot but well worth it for what it does. First piece I tried went on the base of my Conqueror tone arm. It was only about 1/4" by 1" long. That was enough to hear improvement. Not a lot of improvement but 1", come on! 

The thread here where I first heard about it they guy has bought many sheets and uses it all over the place. Tone arm, RCA and power cord plugs, outlet covers, circuit boards, caps. Does not dampen in the normal sense of things we are used to that suck the life and dynamics. This works more at a very micro level where it reveals detail by removing smearing. 

Brass I think works more because it has a bit more stiffness and a better vibrational profile than mild steel. By that I mean it vibrates in a way we like. Which is after all why we make so many instruments out of it. 
millercarbon,
Maybe I'll bite the bullet and try that tape. I saw it online, but where do you get it from?
MC: Peter knows more about audio than you can ever dream to know.  Im with him on this one....makes no difference.  Peter built me a pair of his Master Reference speakers years ago with all brass screws.  I had it done for looks, as it made no difference in the sound.  
Got mine off eBay. Prices and shipping varies so compare around. Its a lot more expensive now than last year! Thin and thick are the same except for thickness. One sheet is pre-cut into strips of different widths, the other is uncut. Excellent adhesive, I recommend using tweezers and leaving part of the backing in place to help line it up right where you want it. Thin is great on tone arms, caps and stuff, both thick and thin work great on speakers, circuit boards, etc.
I suspect Vandersteen et al would substitute their black metal screws with brass if the sound could be improved
Mapleshade has recommended brass screws for years, and no, they do not sell brass screws...
Nice to see Aunty Fuser displaying his normal level of ignorance.
No surprise there.

Well for the cheap entry price into brass screws I am going to have to give it a try.
At least with my Spatial OB speakers they are all accessed from the back so wonder how that measures up against normal drivers that are screwed in from the front??
roxy,
If the fO.q tape is more than you’re willing to spend right now, there are other vibration damping tapes on the market for less.
I cannot vouch for the efficacy of any of them, as I have never used any, compared them, nor heard a system with them in it.
So maybe try a cheaper tape, and if you feel it makes a positive difference, go for the fO.q tape in the future.
@ ROXY54 I try all solid brass screws back in 1983 on the woofers, horns, crossovers, on my jbl 4435 studio monitors. Because of there non magnet property i thought it would make a (SQ) change but it did not. I was said about it but it looks real cool. And yes i tried it before i said it will not make a change. In my rig....
In 2002 I started a thread on Audiogon about modifing my Dunlavy SC4s included were replacing all the ferrous fasteners with brass including rebuilding and taking the crossovers outboard. Coating the inside walls with Cascade V Bloc a sealer that dried like concrete..a big improvement.  Tom
Souljasmooth- If you read millercarbon’s Tekton thread, he replied that he was “amazed” at the improvement this little tweak made: “Yes roxy54, and now you see how amazing one seemingly minor little tweak can be” when most people hear nothing or very little if anything.
Also, this is from a person that thinks his moabs are better than the (in MC’s words), top of the line million dollar Wilson speakers, (but Wilson doesn’t make a million dollar speaker, he just used it for exaggerating purposes), so his hearing is questionable at best.
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Ok let’s look at it from the Old mechanics point of view. There are different types of brass. Some brass is slippery. :-)
The material is used as a normal wear part, it is used a LOT, in harsh environments. It has a different dampening effect depending where and how it’s used.
Brass securements with "double binding" washers won’t back out, IF they are torqued correctly...

When things are tight, they do not vibrate. IF thing are NOT tight they will BREAK!!! Ok you can add all the HOOP la you want..

IF IT’S tight, it won’t vibrate, if it’s loose it will...

The speaker rim (for the lack of a better name) needs to be
Secured correctly, with the correct binding head and locks
FLAT, not warped, torqued, in sequence and correctly.
SEALED, it CANNOT leak. AT ALL!
I’ve used Brass, Bronze. Copper, Stainless, Sheetrock screws (high carbon I reckon) internal HEX, Torex, la-te-da.

I use what looks nice, and I can torque to correct specs, easy Dudes and Dudettes!!

If it’s tight, and sealed, it’s dampened, and right...

What does that mean to me. ANSWER. The screws should NOT make a difference, if they are TIGHT.
LOOSE YES, Not torqued correctly, YES. Not torqued in correct sequence, YES.

Easy check, get a stethoscope, scope every screw UNTIL it has the same tone.. Just like tone tuning a spoke, wheel.

I bet YOU can hear better than you think, with a good tube scope, or a heart scope will work (10-20 USD) I use them all the time. STILL

LISTEN. You’ll see, or HEAR. :-)

Regards
OP if it's the same density, sending a controlled tone you can hear the difference. This is just in stereo.. You can use just a tube and put it to your ear over the securements. Hit the tone, and listen... Tighten for a higher pitch...., Try not to back off.

Torque to TONE.... Old Ways...

Regards
Torque to TONE.... Old Ways...
This could be the best post here. 
oldhevymec, seems you're saying vibrate when what you mean is rattle. Tight won't rattle but everything vibrates, only question is how. You're probably right about torque to tone. Tighter probably is higher in the same way a guitar string is adjusted higher by tightening. The difference being the relatively stronger screw is going into MDF and probably cannot be tightened anywhere near enough for this to be noticeable. What probably would be noticeable is tightening compressing the gaskets. Just not to the degree of tone you're talking about. Lots of people tighten mounting screws, I sure have, never heard anything like this though.
What about gold-plated brass screws?
Remember the first Krells?  KSA50 and KSA100.  They have these fixing the front panel to the chassis.

Now I had always thought they were there as decoration????


Brass is an alloy of copper and zinc.  Small amounts of other metals are often added.  Crucially the proportions of all the contituents is variable.  So the content of brass is not fixed as for say iron.

Point no.1       Not all brass is the same, so why expect the same results?


Brass is non-magnetic (if there is no iron in the mix).  Speaker drivers have big powerful magnets in them.  In the case of a smallish speaker the fixing screws will be within a few inches of the magnet and within its magnetic field.

Point no.2     Clearly the lack of magnetism in the fixing screws will have a real and MEASURABLE effect on the action of the magnet on the driving coil, as compared with steel/iron fixing screws.


In a properly designed speaker, the drivers will not be fixed to the cabinet with wood screws.  Obviously these will work loose very quickly because of the vibrations of the driver.
They should be fixed with bolts running right through the cabinet wall and held in place by locked nuts that cannot unscrew.
They should be torqued up very tightly to ensure that the cabinet wall and gasket material are compressed as far as possible to minimise any looseness that may be caused by future compression.
Gasket should be as thin as possible to minimise variable compression.
Not rocket science, just sensible and simple engineering.
MC, yes for our purpose, call it "rattle". If it's tight, (driver to cabinet) it is as ONE... If you listen with a scope say 2" from the screwface, note that tone and THAT SPOT (need to mark your measurement spots)
Torque, and listen.. If there is a "Rattle", that's real bad. The two pieces are NOT bound one to the other. Torqued properly...Recheck for TONE. Kinda see the difference?

We don't want a "given amount of movement" between the two pieces.
EX: Head to block, they move....

"No movement torque"...different kind of torque spec. This is the engineers job.... Not the mechanic... BUT, we'll fix it anyway. 

I'm not trying to come off as a "SQUINT" OK!!! Get to "squinty"
I can't keep up. :-)
  
We are looking to TUNE each securement to the same tone, via ear.
I suppose you could measure it pretty easy, if you need to, (for the measurement crowd). Then move your scope (pickup) over the securement. I TRY to get them all the same (tone) 2-4-6" away.
I try to TUNE/Torque so I don't have to do it again.

The above method will show you how BAD Big Box store 11-15 plywood really is..  HUGE voids... (internal wood rattle).  It will DRIVE you nuts, kind of noise. HARD to fix outside and look good, kind of NUTS... :-(

If you have a breakin (tone gen) for say 24-36 hours, recheck your securements. I've done it so many times, I can still hand torque to within 10 inch lbs of torque. Then see if it holds. It always does NOW..
If they come loose (never have), they NEVER come loose again. Silicone/thread locker/JB weld/binding head SS lock washers/nylock nuts/pinch nuts!!!

I use a (2-3) stage CROSS pattern torque too. 

OR Torque to tone if YOU want to. You know, learn something. :-)

MDF is easy to OVER torque... If it's too tight, it will warp the speaker rim and or pull the threads... If it's to loose, it will come loose again and pull the threads. When it's torqued RIGHT, and the screw HEAD is bound, it CAN'T move. If you can't get it tight enough, Half moon hardwood backers for the bass drivers. 3/8" thick 1-2" wide. Oak or Apatong. 60-160.00 usd PER driver.

Load 20 BASS drivers, gets spendy. You can make your own.  20.00 for 8", 30.00 for a 12", 1/2 red oak. few tools..

Regards

Another word of caution against over-tightening of drive units.  

Don't do it.

As mentioned earlier it alters the tone, but it does more than that, it alters the amount of resonance pumped into the baffle. Since the baffle due to the cutouts is normally the weakest part of the cabinet, you certainly don't want more resonances there. 

With large drivers the issue becomes paramount.

Some, like Harbeth only recommend finger tight, and I tend to agree.

Over-tightening in my experience often results in an uptight and dynamically constrained sound. 

For sure there are better ways of attaching drive units to the baffle, but they are all more time consuming and more expensive to implement than simple wood screws.

Here's what Siegfried Linkwitz had to say on the subject.


Mounting a driver to a baffle

'Typically a loudspeaker driver has screw holes in its basket for mounting it to a baffle. Usually a sealing gasket is placed between the driver basket rim and the baffle. The driver becomes in effect stiffly clamped to the baffle.

This method sets up a mechanically resonant structure which is formed by the compliance of the basket and the mass of the magnet...

A) Drivers with a stamped metal baskets are prone to exhibit a high Q resonance when tightly clamped to the baffle. The magnet moves relative to the voice coil at the resonance frequency. Energy is stored and also readily transmitted from the moving mass of the cone into the cabinet.

B) Soft mounting the driver basket to the baffle using rubber grommets reduces the resonance frequency. A 2nd order lowpass filter is formed that reduces the transmission of vibration energy from the moving cone to the baffle and cabinet. The resonance must occur below the operating range of the driver.

C) If the driver is mounted from the magnet and the basket rim touches the baffle only softly, then the magnet-basket resonance cannot occur and the transmission of vibration energy into the baffle is minimized. The basket-magnet resonance can be measured with an accelerometer that is mounted to the magnet.

The drive signal is optimally a shaped toneburst.

Its energy is concentrated in a narrow frequency band. When tuned to the right frequency a long decay tail becomes visible on an oscilloscope. Often the resonance can be seen as a small bump in the driver's impedance curve in the few hundred Hz range. It should not be confused with the higher frequency bump due to cone breakup.

An early example of a box loudspeaker where a KEF B110 midrange/woofer driver magnet is clamped to a support structure. The clamp can be tightened from the outside of the box. The basket rim is floating.

Often the effects due to driver mounting are deemed to be of secondary importance to the overall sound quality of a loudspeaker. They are usually costly to remedy. They cannot be ignored when the goal is to design a loudspeaker of the highest accuracy.

http://www.linkwitzlab.com/frontiers_2.htm#N
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I read this discussion with great interest. So I just checked my Revel Salon 2's. Yep, little black screws! What a cheap way to finish off a pretty good speaker. 
Mapleshade used to have a more detailed explanation of replacing the speaker mounting screws. Now they just suggest it. Find it under speaker tweaks.
https://mapleshadestore.com/freeupgrades.php

If anything, it will make your speakers look even more....special?


If anything, it will make your speakers look even more....special?
Not on my Spatials....unless of course you are standing/sitting behind them.........
If you read millercarbon’s Tekton thread,

You will be amazed.
he replied that he was “amazed” at the improvement this little tweak made:
No. Wrong.
“Yes roxy54, and now you see how amazing one seemingly minor little tweak can be”

See? Didn’t say I was amazed. The subject of the sentence is roxy54.
when most people hear nothing or very little if anything.
And "most people" is millercarbon? I don’t think so.
Also, this is from a person that thinks his moabs are better than the (in MC’s words), top of the line million dollar Wilson speakers,
Never said top of the line. Said better than ALL Wilson.
(but Wilson doesn’t make a million dollar speaker,

Never said they did.
he just used it for exaggerating purposes),

Its called poetic license.
so his hearing is questionable at best.

Compared to your reading comprehension its off the charts. Is there anything you can read and understand? See Spot run??
“it improved the detail in ambient trails, focus in general, complex harmonics in voices and stringed instruments, and instrumental separation. It is not subtle, and it is immediately noticeable.”

millercarbon would do any and everything to make his $4500 Moab’s look and sound like $100K speakers...all in the name of audible improvements. Brass screws...it’s like putting a lipstick on a 🐷

What’s next, a splash of pixie dust in the air each time you sit down for a magical listening session :-)
FINGER TIGHT? Sorry I'm rolling on the floor. That is a "I don't know how to tighten things" answer. I'm actually rolling on the floor... Me the dog and the rabbit. This is a builder (not engineer) answer to a poorly designed baffle, and driver securement system..

Ok this is how I see it happening. A driver manufacture measuring their projected driver response, looked good so they had a few thousand produces in CHINA. Then  found "MOUNTING" the driver changed the "Q" res to baffle. WHY? Forgot to figure in mounting the thing...AND
a soft baffle (my guess).

If anyone purchased a driver that couldn't withstand TORQUE, or designed one that way, it is FLAWED, simple.. If proper torque caused a driver problem, usually the baffle face is not flat. 
I have seen this EXACT same thing with neo planar (UPGRADE) added securements and properly torqued. VMPS neo 8 upgrade...To stop ribbon/planar distortion and usually material failure.

It sounds like they over torqued the basket, then under torqued, the basket.  Then settled for what they could keep the tightest the longest. But not tight, FOREVER... To keep the tonality the same day in and day out.... Can't keep torquing them up...OK

You have to torque and tighten EVERYTHING.... No exception. 

A moving torque method is good for a diesel engine (head to block).
But not where you want ZERO WEAR, You want ZERO wear in the driver pocket and the back face of the driver flange..
Finger tight.. Is that funny bunny, I'm talking to my rabbit (Junior)?
The Goat, I'm still pissed at because of the hat he ate...

Time to definitely feed the chickens, squint, squint. Palm to the head slap! Why do I even try to teach these chickens how to fix their own hen house.. silly me... Good to be the Rooster I guess.. :-)

BTW, now you see why a speaker sound engineer, is kinda low on the totem pole of engineers. It takes a mechanical engineer to fix the problem working with a GOOD sound engineer...to correct ALL issues with the box and drivers...or

maybe an OL wore out mechanic...OOPS, did I say that...

Regards
Before we start criticizing and poking fun at him perhaps we should ask cd318 to explain exactly what he meant by finger tight. I am a Harbeth owner and I don't see how I could do that with the screws securing my drivers. I can understand not using a impact driver, I just don't understand hand tightening this type of screw. Cd318 might have a perfectly logical explanation that just wasn't obvious to us.
brass  screws  is not audiophile approved , you have to send screws
to stereophile to make acoustic measurement  and we have to see difference .  also is very important the  screws  size . you have to drill bigger holes and use big screws. Fantastic improvement
Hello,
One of the reasons manufacturers hate to use brass screws Is they are hard to keep perfect and scratch free. They have to be hand tightened which makes it difficult to torque with a specific amount of weight. Even on an expensive speakers it is something that could cause problems. Also you probably need a revealing system to hear the difference. Last is it costs more. Maybe not a lot but it adds up. I will bet you it might only cost about $20 to try it. What’s the harm. We all spend thousands of dollars on our hobby what is $20 more. Also, sometimes people ask how did the electronic measurements look or differ. Do you know how many speaker manufacturers have a perfect measurement but the prototype speaker sounds bad. A lot! I think we should try it and post our results on this thread. Maybe we can get the screws from Ace Hardware. They carry a ton of specialized harware. If they don’t work return them. Cover the screw driver head with tape so you don’t mar them. If they do work. Good for us!
“it improved the detail in ambient trails"
I usually just smoke another joint for the best ambient trails. Yea, I find it to be one of the best tweaks.
Not too good for your lungs though...
@cal91,

'I am a Harbeth owner and I don't see how I could do that with the screws securing my drivers.'


As an Harbeth owner perhaps it might help to be a little more familiar with the Harbeth website?

Alan Shaw stated that it's no big deal as long as you're sensible and use no more pressure than is required to meet resistance. 

Basically - Don't go mad!!

If you're really struggling I can try and dig up his exact words for you.


As for brass screws, let's not even go there!

How about simply trusting the manufacturers?

The people whose livelihoods depend upon their products.

The people who have spent a lot of time and resources building loudspeakers.

I might not like a lot of loudspeakers out there, but I'm not going to pretend for one moment that I, with my severely limited resources and knowledge, could do any better.

Seriously, if anyone is considering ruining their speakers in this way, it might be wise to contact the manufacturer first if they are of any value to you.