Need some advice for modding a rumble

[Hoochie Coochie Man]

I mentioned overtightening because I see a lot of damage from over tightening in spite of the customer insisting that they didn’t overtighten.

When I worked for a company that designed very high-tech robotic equipment for the semiconductor manufacturing industry we used this low strength thread locker on small knurled lock rings found on small pneumatic flow control adjustment devices: Vibra-Tite VC-3 Threadmate It keeps threaded fasteners similar to the nut on a potentiometer tight, yet can be broken loose by turning the nut with a tool, (wrench, pliers), even by fingers.

Back in an earlier job at a GE Medical Systems circuit board test lab we used a product called Glyptal to keep trim pot adjustments from moving, (also worked to show tampering). I don't think they still sell that hazardous chemical laden product anymore. It was a small glass bottle with a brush built into the cap. I think it was an enamel.

Potentiometer nuts could be kept from loosening yet not be over tightened by using something like this.

A very small dab of fingernail polish may have the same effect.

(I accept no liability for any bad results anyone gets from using finger nail polish for this purpose ).

 

[MrLenny1]

Bummer. Things ain't what they use to be.
My 30 year old Bag End 15 has held up to serious abuse.
i.e. fallen down staircase, hit by the van, fallen out of the van etc...
and no rattles. Go easy on the screws.

 

[Drop1]

Bummer. Things ain't what they use to be.
My 30 year old Bag End 15 has held up to serious abuse.
i.e. fallen down staircase, hit by the van, fallen out of the van etc...
and no rattles. Go easy on the screws.

It was only the jack nut. No big deal.
I mean the unit does make some noise at loud volumes, but at that point the sound easily drowns it out and the room is making WAY more noise.

 

[shoot-r]

Bummer. Things ain't what they use to be.
My 30 year old Bag End 15 has held up to serious abuse.
i.e. fallen down staircase, hit by the van, fallen out of the van etc...
and no rattles. Go easy on the screws.

+1!

Ying/Yang, give or take, equal but opposite reaction, add here/subtract there, change something here changes something there, ect., ect.

As we move away from old school, very durable, bass cabinet construction of using heavy duty (and heavy in weight) 3/4" voidless plywood to super thin plywoods and now composites for weight savings, something "has to" change.

The changes seems to be, if the light weight cab isn't overly braced inside, it'll flex/rattle/buzz, if the cab goes down a staircase it'll probably crack or splinter the outer shell.

I went to gigging a light weight 212 cabinet in a working band alittle over a year ago.
I baby it like I never did the old school constructed, 3/4" plywood, 810 cab I drug around for 29 years.

Before I purchased one manufacturers light weight cab I e-mailed them a question, "could I add casters to their cab", answer was, "no, they'll cause stress points and crack/split the cabs enclosure."
They also recommended I always use heavy built road cases while in transit, (so much for the weight savings.)

Only time will tell how these lighter ply cabinets will stand up to working band/touring use.

 

[KenB]

Oh I'm not talking about anything major that you'd hear in the context of a band.

It's definitely not anything you'd be able to hear at a gig.

The amount of time and effort spent tracking down and silencing a bass cabinet will always be inversely proportional to the distance from the snare drum at the next gig…

 

[Drop1]

The amount of time and effort spent tracking down and silencing a bass cabinet will always be inversely proportional to the distance from the snare drum at the next gig…

I'm not gigging with it. I wouldn't gig with it. It's a bedroom unit for me (living room technically) and it's only temporary until I find what i really want.

 

[fhm555]

I can hear when a a noise is coming from the cab or room. It's not difficult. I can tell you right now there are a BUNCH of rattles in the house. But there is a small one coming from the top back right near the gain control on the cab. I haven't figured out if it is the jack or the knob but I'm fairly certisn it's one of those 2. If I can make a whole car interior not rattle , I'm sure I can handle a cab.
Something else I know. Blanket coverage "rarely" works for specific noises. Sometimes treating panels helps a little but I find it much better to identify exactly where the noise is coming from and coming up with a tailer made solution to address every instance with it'd own solution.

That solution could be a bit of butyl, a bit of non hardened modeling clay, a rubber band, a drop of silicon in just the right spots, closed or open cell foam and a slew of other things. I've used all kinds of approaches depending on where the rattle is and weather or not its in an electrical component like switches or care needs to be taken to not block drainage or stop moving parts from functioning properly.
You like to pick on my about car audio, but imagine for a moment what it takes to makes all those resonating parts inside a car inaudible. It took me months to find the last rattle on my truck but she's dead silent now. That last rattle was a mid bass driver causing the passenger door mirror to vibrate where it clamped into the mirror housing. Tracking physical noise isn't new to me and I'm very, VERY good at it.

I'm fact, during the span of me typing this ibe already found the main noise on the cab. The nut on thr input jack was slightly lose. Just finger tightening made it stop.
There is a buzz on the shelf behind the cab, but I don't feel like looking for it right now lol.

Maybe having a talk with a pro about OCD would solve the rattle problems? Take it from a fellow traveler who finally broke down and sought a professional opinion, it’s nothing hard, but the result is well worth the effort/expense. It was most liberating.

 

[agedhorse]

When I worked for a company that designed very high-tech robotic equipment for the semiconductor manufacturing industry we used this low strength thread locker on small knurled lock rings found on small pneumatic flow control adjustment devices: Vibra-Tite VC-3 Threadmate It keeps threaded fasteners similar to the nut on a potentiometer tight, yet can be broken loose by turning the nut with a tool, (wrench, pliers), even by fingers.

Back in an earlier job at a GE Medical Systems circuit board test lab we used a product called Glyptal to keep trim pot adjustments from moving, (also worked to show tampering). I don't think they still sell that hazardous chemical laden product anymore. It was a small glass bottle with a brush built into the cap. I think it was an enamel.

Potentiometer nuts could be kept from loosening yet not be over tightened by using something like this.

A very small dab of fingernail polish may have the same effect.

(I accept no liability for any bad results anyone gets from using finger nail polish for this purpose ).

I don’t recommend any of this, it’s just unnecessary. Glyptol is still used for some applications in the transformer industry.

+1!

Ying/Yang, give or take, equal but opposite reaction, add here/subtract there, change something here changes something there, ect., ect.

As we move away from old school, very durable, bass cabinet construction of using heavy duty (and heavy in weight) 3/4" voidless plywood to super thin plywoods and now composites for weight savings, something "has to" change.

The changes seems to be, if the light weight cab isn't overly braced inside, it'll flex/rattle/buzz, if the cab goes down a staircase it'll probably crack or splinter the outer shell.

I went to gigging a light weight 212 cabinet in a working band alittle over a year ago.
I baby it like I never did the old school constructed, 3/4" plywood, 810 cab I drug around for 29 years.

Before I purchased one manufacturers light weight cab I e-mailed them a question, "could I add casters to their cab", answer was, "no, they'll cause stress points and crack/split the cabs enclosure."
They also recommended I always use heavy built road cases while in transit, (so much for the weight savings.)

Only time will tell how these lighter ply cabinets will stand up to working band/touring use.

I certainly don’t agree with this recommendation for the Subway cabinets, casters are plenty fine, though I always recommend using the proper hardware (ie. T-nuts).

 

[Drop1]

Maybe having a talk with a pro about OCD would solve the rattle problems? Take it from a fellow traveler who finally broke down and sought a professional opinion, it’s nothing hard, but the result is well worth the effort/expense. It was most liberating.

I do have a bit of ocd. I dont mind it. It makes me do well at work. (I remodel interiors for a living.)

My problem with rattles or vibrations came from car audio. I compete in high level sound quality organizations and we get docked serious points if they can hear anything but music.
Trying to make a car Interior silent is kinda tricky when you have 8 inch mid bass on 500w each in the doors and an ib 15 playing down below 10hz lol. The whole Interior is resonsce city and it takes a lot of careful damping and foam placement to absolutely minimize as many resonaces as possible. Even resonaces you can't hear can affect the overall response. But when you do get it quiet, it's beautiful and that has carried over to other things with me. Once I settle on where my cab will be placed, I will track every cab or room noise down and eliminate them 1 by 1. It CAN be done and to me it's worth it. Well, to my ocd it's worth it.
I imagine a good bit of screws, liquid nails and sheet rock mud are in my future as well as a good bit of time in the attic since most the room noise seems to be coming from the ceiling.

 

[Pocket Dave]

+1!

Ying/Yang, give or take, equal but opposite reaction, add here/subtract there, change something here changes something there, ect., ect.

As we move away from old school, very durable, bass cabinet construction of using heavy duty (and heavy in weight) 3/4" voidless plywood to super thin plywoods and now composites for weight savings, something "has to" change.

The changes seems to be, if the light weight cab isn't overly braced inside, it'll flex/rattle/buzz, if the cab goes down a staircase it'll probably crack or splinter the outer shell.

I went to gigging a light weight 212 cabinet in a working band alittle over a year ago.
I baby it like I never did the old school constructed, 3/4" plywood, 810 cab I drug around for 29 years.

Before I purchased one manufacturers light weight cab I e-mailed them a question, "could I add casters to their cab", answer was, "no, they'll cause stress points and crack/split the cabs enclosure."
They also recommended I always use heavy built road cases while in transit, (so much for the weight savings.)

Only time will tell how these lighter ply cabinets will stand up to working band/touring use.

One case study:

I bought a super-low-cost Acoustic B410C a couple years ago that came with 1/2" plywood. With ferrite magnet speakers, not neos, it was about 25-30 lbs lighter than a comparable 3/4" ply 410.

Thing is, it's actually braced well and tightly built with 0 rattles (@Drop1 - yes, even isolated from a band), though there's still significantly more cab vibration than my past SWR Goliath II 410. I carry a section of 1/2" yoga mat foam to set my lightweight Aggie TH500 on.

In terms of robustness, it's been bumped, dragged and wheeled across all kinds of bumpy surfaces and has shown no sign of structural/core-strength compromise. The one thing I noticed early on was the plywood was still fresh and prone to denting. A couple seasons of outdoor gigs in Texas heat seems to have fixed that - The plywood has dried and hardened for whatever reason.

Side note: I replaced the cheap 100-watt traditional speakers with 200 watt Emi BP102's, also traditional, because the 100 watters were starting to bark on outdoor gigs covering larger areas without FOH support - There's one we do a month like that. You'd think these extra-punch/extra-headroom speakers would push the cab beyond its limits; They have not.

 

[Drop1]

I don’t recommend any of this, it’s just unnecessary. Glyptol is still used for some applications in the transformer industry.



I certainly don’t agree with this recommendation for the Subway cabinets, casters are plenty fine, though I always recommend using the proper hardware (ie. T-nuts).

Agedhorse.

If I were to identify the exact horn tweeter being used in this cab, would you be able to recommend a smoother sounding horn that may be a drop in replacement?

After connecting the cab to my computer and applying some fx, I can get the cab to a solid 95% acceptability. For me it doesn't get much better, but the tweeter is a bit harsh for my liking. I "need" the tweeter. The cab isn't the same without it, I just wish it were smoother sounding and If I can fix it for the cost of a horn, that would be awesome!

And If not, surely there is a way to add variable attenuation to the horn , or maybe a way to vary the tweeters high pass?

 

[Hoochie Coochie Man]

With many electronic devices that I buy, (new and used) I often partially disassemble them just to see how it was designed and how it was constructed. This is especially true of musical instrument amplifiers and instruments. As part of my inspection (just to satisfy my curiosity), I often will check things like how tight the nuts on potentiometers and other fasteners are, as well as other standard electronics visual inspection QA measures.

In an earlier post in this thread I mentioned some products that may be used to prevent threaded fittings from loosening due to vibration. I should have made it clear that I was not recommending the use of removable thread locking products on music gear, but was just pointing out how some industries add a little insurance against loose hardware being a problem. I do not use any of them.

On new products I often find hardware that is, (in my opinion) not as tight as it should be. I prefer to find something not tight enough rather than over-tightened. I use my own judgement, (and my "experience-calibrated wrist torque measurement system") to make sure everything is good to go.

I also have developed the habit of pressing down on any socketed integrated circuit devices. I often find that when I do this they seat a little more firmly than they were initially. I assume dual-inline-package devices like the common TL072 op amp found in a lot of audio gear are still inserted by hand, and so I like to make sure that they are fully seated in the socket. One time in a design review meeting when I suggested that a certain device on a circuit board (that required extremely high reliability) be socketed, an older (and wiser?) EE responded that it was a bad idea because (according to him) socketed DIP devices are prone to "thermal creep" which causes them to unseat themselves over time due to thermal cycles. This is essentially a "tightness" issue as well. I don't know if it is a real thing, but I did write a little instrumental jazz tune about that time that I gave the temporary working title: "Thermal Creep" just because it sounded cool.

 

[Mike Caldwell]

Agedhorse.

If I were to identify the exact horn tweeter being used in this cab, would you be able to recommend a smoother sounding horn that may be a drop in replacement?

After connecting the cab to my computer and applying some fx, I can get the cab to a solid 95% acceptability. For me it doesn't get much better, but the tweeter is a bit harsh for my liking. I "need" the tweeter. The cab isn't the same without it, I just wish it were smoother sounding and If I can fix it for the cost of a horn, that would be awesome!

And If not, surely there is a way to add variable attenuation to the horn , or maybe a way to vary the tweeters high pass?

An adjustable L pad would let you change the level the of the tweeter.
It would go between the crossover and tweeter, needs to be the same impedance of the tweeter and at least if not more the power rating of the tweeter.

 

[edwinhurwitz]

I certainly don’t agree with this recommendation for the Subway cabinets, casters are plenty fine, though I always recommend using the proper hardware (ie. T-nuts).

I'm amazed that the original small casters on my '67 Sunn 200S cabinet are still going strong. I've abused them mightily and keep thinking that I'll replace them when they break. Not yet!

 

[agedhorse]

An adjustable L pad would let you change the level the of the tweeter.
It would go between the crossover and tweeter, needs to be the same impedance of the tweeter and at least if not more the power rating of the tweeter.

L pads are often rated as “system power” based on 1/8 continuous audio power. It can be very misleading.

 

[agedhorse]

Agedhorse.

If I were to identify the exact horn tweeter being used in this cab, would you be able to recommend a smoother sounding horn that may be a drop in replacement?

After connecting the cab to my computer and applying some fx, I can get the cab to a solid 95% acceptability. For me it doesn't get much better, but the tweeter is a bit harsh for my liking. I "need" the tweeter. The cab isn't the same without it, I just wish it were smoother sounding and If I can fix it for the cost of a horn, that would be awesome!

And If not, surely there is a way to add variable attenuation to the horn , or maybe a way to vary the tweeters high pass?

Nope, because it’s not a simple “pull a better tweeter out of my butt” answer since it’s very much a system answer that includes the response of every component in the speaker system.