Brass screws make a real difference on Dunlavy s ?


As some of you know, I have just about every model speaker John Dunlavy ever designed. I've tried a few tweaks, but never replacing the standard driver attachment screws with brass ones. I've read some posts that it really does make a difference, but before I make a run to the hardware store, I would appreciate any thoughts on the matter. Thanks in advance!
brauser
It'll make absolutely ZERO difference what the screws that attach the drivers are made from.

What will make a difference is how tight the screws are, so if you want to try a very simple tweak tighten up all the screws that holds the drivers in place. Don't know if Dunlavy used inserts/machine screws so make sure you don't over tighten.

So if some one claim that they can hear a difference after replacing the attachment screws with brass ones it's not because they are made from brass, its because they now are tight.

Good Listening

Peter
On most speakers brass DOES make things sound a bit better, on single-drivers often a big difference.
I'd have to go with Peter on this one. My Duntech Princess speakers benefited from tightening the screws holding the drivers periodically, especially the woofers, but you do have to be careful not to over tighten (the Duntechs had inserts for the screws that could come loose if you went too far with the tightening).
Rcprince is absolutely right on his post above. Also, if you don't have inserts and your screws are just going straight into MDF or Plywood, you run the danger of stripping the threading in the cabinet. Be careful.

One other issue I've read about concerning tightening the screws is that it can be possible to tighten them too much to the point where the frame/basket gets out of true. In those instances, the driver and surround are not operating in a true single plan and the pistonic motion of the driver can be affected.

Not sure if this is true or not, but if you think about it, it certainly seems entirely feasible.

Back to brass screws. I have no idea if it makes a difference or not, but years ago, it was suggested as a tweak to the owner of Omega speakers. Louis (The owner) liked it so much that he now uses brass screws on all his models.
Dunlavy speakers have no threaded inserts. Dunlavy speakers do sound better with brass machine screws on all the drivers as well as the tweeter mounting face plate. Replacing the steel mounting hardware with brass on the crossover back plate ..improvement there can also be heard.

Brass is the metal of music. Brass will also interfere less with the flux field whether that field is stationary or moving. The use of brass fasteners are beneficial on most every type of application in audio electronics. Tom
Peter, I learned it from above source, Louis at Omega Sound who is as honest a person as there is in audio.
It worked very well on my Omega 3XRS .
Also improved a bit my Rega RS-3, Gallo CL-3 and Totem Model 1 Sigs.
After 45 yrs in audio I'm not much for tweaks , brass screws
are only one I found helpful in a long time.
Upon reflection I did not try them on my Totems, some other one my elderly brain can't recall.
Interesting.

Would seem to be a fairly insignificant difference, but if honest people who have heard hear a difference, then so be it.

Plus brass screws usually look nicer for sure, so that can't hurt.

One other thought. It usually always helps to make sure screws of any kind are tightened securely. that could be part of the change that one would ahve to factor in that could account for at least some portion of the difference if things were not as tight/secure as they should be to start.

My big OHM F5 drivers attach to teh base via wingnuts (not brass). These work loose over time and are easy to tighten. Things always sound better after a good tightening, even with no brass in the picture.
Brasier, I owned Duntech Princess speakers for 19 years, though I no longer have them. The Duntech models do have inserts/machine screws, no idea about DAL models.

Like Rcprince, I found it was beneficial to tighten screws and checked them about once a year. When I did that it was usually the woofers where it made a difference. Never using a torque wrench (!) I simply tightened each one snugly by hand, without trying to bare down a hard as I might.

I do remember reading a recommendation for brass screws but never tried them. Since I kept them 19 years it should be obvious I was pretty happy with their stock performance.
Well, I took your advice and decided to tighten the screws on the SC-V(s)and everything in the HT room ranging from the SC-IV(s) to the SC-I center channel. Some of the screws were very snug to begin with while others took a couple of rotations to tighten to a solid point. Putting on some high rez very familiar music showed the effort to be worthwhile. Not talking about an earth shattering difference, but observable.

Many thanks!!
Interesting. Just remember, the next step after nice and tight is really loose.
Many of you report a difference after tightening the screws on the drivers ("it helps", "it was beneficial", "worthwhile") and I remember reading of this before. No one in the thread describes what changes occurred to the sound of the speakers after tightening the screws. Bass more extended?, resolution improved, clarity improved?, more coherent?
Martin Colloms' article on, "PRAT" gives some good descriptions of how and why tightening speaker system screws can affect your reproduction. Especially page 5: ( http://www.stereophile.com/content/pace-rhythm-dynamics-page-5 )
Good question(s) Foster. What I noticed was a modest amount of additional transparency. It is the sort of improvement you get when using a good CD cleaner or beveling the edge with a lathe. Last night was fun using some very familiar high def CDs as reference, and then applying most all my standard tweaks in addition to the tightened screws. I have never heard the reference two channel system sound better. This evening I plan to do the same sort of thing to the reference HT room to see if similar improvements are found. I will post the results.
Foster--in my case the bass was better defined, the sound a little more transparent as a result. Not earthshaking, but noticeable.

When people wonder "Why don't more people love (high end) audio?" threads like these are exhibit A. Audiophiles don't get a nutty reputation out of nowhere. ;-)
Wait a minute...are you guys talking about re-tightening screws that were loose? Which would be like proclaiming that your car is less jumpy because you replaced the broken motor mounts...well, yeah, duh. Or are you saying that you're actually hearing better sound by over-tightening screws that are already properly seated, and you're tightening them beyond what the manufacturer's quality specs dictated?

If it's the former, nobody gets a trophy for discovering they get better sound if the drivers aren't about to fall out of the cabinet and crash to the floor. But I'm sure nobody would debate that...sorta goes without saying.

If it's the latter...are we to conclude that these speaker designers - keeping in mind that you guys aren't talking about white fan specials, but well-designed products from highly-respected manufacturers - put all that time into creating these fine products but only half-assed it when it came time to attach the drivers, and they'd have actually created better products if only they'd taken a minute and turned their screws a little further?

Have to be candid here...I can't read this thread without repeatedly checking the calendar to make sure it's not April 1.
It's obviously a magnetism issue. Even teflon screws will illustrate that. The ferrous type screws cause a subtle but quite audible perturbation in the magnetic field lines of the speaker magnet. Another option would be to demag the screws periodically. Be sure to demag all those tiny ferrous screws on the component chassis while you're at it.

Also energy can be drawn in a particular direction by mechanical force or tension. If you have a speaker driver that is to be secured with multiple fasteners then all those fasteners should be tightened the same. Like a drum head the energy should be spread evenly around the circumference. In this way the wave launch from the driver will be more linear and piston like on all areas of the cone or driver. Tom
To answer a couple of comments/questions, I just simply tightened all existing driver mount screws to a secure/snug level. I did not try to apply a lot of force or torque but tried to bring all the screws to about the same point of rotation. I did this with seven speakers associated with two different systems. As I mentioned before, some screws were already very tight, some I could move maybe a quarter turn and some were loose enough to require a couple of full rotations. The benefits to the two channel systems were readily observable but not earth shattering by any means. The speakers in the HT room were harder to get a gauge on, but overall I would say there was at least some minor improvement there as well.

It's been interesting to see some of the rather skeptical reactions to this post. All I can say to this is that tweaking a system is a process of trial and error, but the cumulative results of staying open minded and incorporating minor changes can have (and often does have) major improvements to a system. That can be true even if the system is performing already at a very high level.

Tweaks are typically the least expensive things to do to a system. In this case tightening the screws took all of ten minutes or so. I then had the pleasure of listening to familiar source material and finding a trace more detail present than I thought possible to extract.
Brauser, the skepticism you likely read in my post comes from the perspective that what you're doing isn't tweaking (or incorporating a minor change, as you put it), any more than inflating car's tires back to spec means you're tweaking that model's gas mileage potential, or fixing a hole in your roof is tweaking a house's weather sealability. All of these things, like tightening those screws that you found needed two full rotations, is simply bringing the item back up to spec (again, assuming that specification for any speaker doesn't include loose drivers). I'm not saying you shouldn't do it, I'm saying that re-tightening loose screws, at least in my personal estimation, isn't a case of finding new improvements in a system, it's simply a case of returning a system to the level you should have been enjoying all along if the screws weren't loose.

The upside of course is that maybe this thread will remind everyone to check your screws, in case the manufacturer did a poor job of securing the drivers and you never noticed before. So, screw away!
Brauser, actually your OP was focused on brass screws not tighening existing screws? Have you forgotten already? Lol
Begator, seems to me you enjoy splitting hairs. Am I to understand that tightening screws to their original tension level is not a tweak, but if they are now secured better than new and an advancement in sound is the result, that somehow this is a tweak?

I guess if drawing these distinctions makes you feel wiser and better about the discussion, I say go for it. Hey, it's a free country.
No Brauser, I'm saying that if you're really experiencing a case of discovering a level of tightening that was either beyond the engineering capability of your speakers' designer, or simply wasn't important enough a quality control concern for the designer to care about, then you bought the wrong speakers. Think about it...what exactly does "better than new" mean? If we can agree that every screw can be tightened to a maximum torque level and perfect seating, either the speaker manufacturer assembled the speakers to specification, or they didn't. And again, if the difference between good sound and better sound is two turns of a screw, what does that say about the speaker designer if they missed that detail when designing and building the speakers? Focusing on "splitting hairs" is missing the point entirely. If you don't see this, then we might as well start a thread about how if we tighten the lug nuts on our car wheels to "better than new" the car will ride better.
If as mentioned above the DAL speakers do not use inserts and machine screws they will come loose to a degree over time, the wood expands / contract with temperature and humidity, this coupled with the vibrations form the driver it self cause this. Its not a matter of poor quality control etc.

The DAL speakers used mainly VIFA drivers, some ScanSpeak, all which can be secured with 8/32 machine screws into inserts. If your up to it Theese work great. You will need a 7/32 drill bit to pre-drill and a 4MM allen key to install them. Then get some 8/32 screws at .625 long, brass if you insist :-) 8/32 by 5/8 Brass Screws although it will not make any difference, and you will not have to worry about this again. Please remember to use a sealing gasket between the driver and the cabinet This works great.

Best of Luck

Peter
Thanks Peter for getting the discussion back to something useful. I plan to keep the Dunlavy(s) for a long time and as they age there will no doubt be a need to find creative ways to maintain or improve their performance. As a side note, I have had some issues with the binding posts on the SC-V(s) and have had to replace some of the midrange drivers. All-in-all, however, I think that the Dunlavy designs are 'true classics' worth the time and effort to keep them in top operational condition.
Never known of any speaker manufacturer to adjust the torque on any of their speaker drivers when mounted into the cabinet and this includes DAL.. except one for sure. If any were indeed factory set there has never been a setting quoted in a shop manual. If there was a quoted torque then that factory setting has changed over time. The screws that hold the mounting frame to the Vifa tweeter mentioned above are metric steel and should also be replaced with brass as these are very close to the moving voice coil and dome. Tom
Merlin speakers have adjusted their driver torque setting and quoted it as one of the changes made when they launched a series update.
I'd just call keeping drivers firmly attached a good idea and leave it at that. Not worth cutting hairs about.
If you cut all those hairs its called good grooming. In this case better sound. All in the details leads to more and better detail. Tom
FWIW I'd call tightening things up maintenance and changing screws a tweak.

The difference is the first is very well likely to result in an audible change to the sound whereas the second is a tougher call, especially if things were not nice a tight to start with.

Not much more to it than that unless someones is still sure the difference they hear/heard is due to changing alone.
I don't think there's any doubt about brass screws sounding better than steel ones. It's not like there hasn't been tons of discussion about this particular tweak for years. Get with the program.
From what I recall about this subject from a few years ago is that brass doesn't resonate as much as steel. Hence their popularity as footers and speaker points and such.
The good news about brass screws is that they are still dirt cheap by audiophile tweak standards. Also they won't rust, though they will tarnish. SO I always tend to prefer them no matter the application. One can go to Home Depot and gorge on them for next to nothing. Nothing to loose really no matter what the sonic effects may or may not be. Just get the right size and thread pattern of course and do not over tighten.
If you have a rust problem in your audio room, you have way more important things to worry about than buying brass screws... like putting a roof on it. Rust is a non-issue in this application and is no reason to replace steel hardware with brass, unless you live on a boat.
Rust is ugly and makes a mess. Otherwise I like it just fine. Not on my speakers though please.

I've never had a rust problem Even with my outdoor patio speakers whose wood finish is practically gone after many years but still sound great.

Not worth losing any sleep over. 😽