Larry's Rings

todmarsden

Is Larry selling his rings anymore?

pitdogg2

nope

xschop

Take 5.5 ID x 6.5 OD steel tube to a machine shop. Tell them to turn the ID to 5.65" and tap 4 holes (8-32) on the MW factory hole centers. Then part them off at 1/4" thick.

xschop

I'll start a prototype...

Toolfan66

Nope!!

xschop

Toolfan, Would these 1-piece rings with integral taps be effective bolted to the inside of the cabinets?

verb

This is interesting. I do applaud you @xschop at your effort for sure!

My take is the critical part and beauty of Larry's Rings are the threaded metal inserts. They effectively eliminate the issues associated with threaded screws, that rely on a robust grip (in shear) to the MDF. Any threaded fastener loses it's grip over time. Hurricane nuts are an improvement, as I used them on my 1C upgrade, but Larry's Rings are the ultimate.

The inserts take all the clamp load, are nicely tied together with the metal ring to negate the torsional force when tightening. Now the MDF layer is only seeing compression, uniformly distributed all along the circumference. IIRC also that the thin ring is necessary as some of the speakers have very tight packaging between the drivers.

From an old thread:

agfrost

I believe I may have taken that pic!

Gardenstater

If Larry doesn't mind.....what's the thickness and width of the steel ring?

verb

agfrost wrote: »

I believe I may have taken that pic!

That's cool! I was going through an old thread, so many links to pic's are long gone!

agfrost

Yeah, photobukit was useful and friendly back in the day.

Larry used to have a sweet video linked of rings being cut from sheet IIRC.

The above-pictured rings are painted because I learned what happens to them over time when I bought/didn't install rings into my RTA 11TL.



Those rings got sold to me, by me, and I believe sold once again! (The painted ones have been installed in my 2BTL)

Sorry for thread derail! To the top!

brgman

What SDA’s do you need them for?

xschop

Them being high tensile steel and 1/4" thick is enough threading for 8-32 integral taps that obviously won't turn. I can radius the inner edge that sets opposite of the baffle interface. However I'm still not sure if this would suffice to ensure that it does not affect rear wave performance of the MW.

pitdogg2

brgman wrote: »

What SDA’s do you need them for?

WOW look what the cat dragged in...

How the heck are you doing ? Welcome back my man.

brgman

Thx Pitt.
I’m jumping back in after a few years of life’s crap.
Finally have time to dust off the gear and enjoy it again.
Need to lurk and see what’s going on here nowadays.

pitdogg2

Good to hear !

Gardenstater

xschop wrote: »

Them being high tensile steel and 1/4" thick is enough threading for 8-32 integral taps that obviously won't turn. I can radius the inner edge that sets opposite of the baffle interface. However I'm still not sure if this would suffice to ensure that it does not affect rear wave performance of the MW.

I missed or didn't realize that you were using steel. Perhaps after you part off on the lathe at 1/4", you could put them on the milling machine and mill out some material in between the threads, leaving them as threaded bosses. If you used a ball end mill you could even leave more material near the bosses and have a rounded fillet there as well.

Gardenstater

Gardenstater wrote: »

xschop wrote: »

Them being high tensile steel and 1/4" thick is enough threading for 8-32 integral taps that obviously won't turn. I can radius the inner edge that sets opposite of the baffle interface. However I'm still not sure if this would suffice to ensure that it does not affect rear wave performance of the MW.

I missed or didn't realize that you were using steel. Perhaps after you part off on the lathe at 1/4", you could put them on the milling machine and mill out some material in between the threads, leaving them as threaded bosses. If you used a ball end mill you could even leave more material near the bosses and have a rounded fillet there as well.

To cut down on the cost of machining and time, one could even just grind away some material in between the threads with a metal cutoff wheel and you could make a bevel so as to not obstruct airflow very much but also retain as much rigidity in the steel ring as possible.

xschop

I've got my 5Bs opened up and I measured the baffle thickness right at 0.5" under the MW lip/seat. Measuring the MW basket oval shape hole distances, I would say that an inner radiused edge would not interfere or add to air obstruction. The real positive is the baffle itself will become very rigid, especially between the tweet/MW and also MW/ passive radiator.

Edited because the computer thinks it knows what I'm trying to say/convey.

Gardenstater

I've noticed that Polk rabbeted the baffles to recess the MW drivers and passives on later models. My 7B's are not recessed, so a little more blockage to air movement but a bit stiffer. A radius would be stiffer than a bevel, but I'm wondering if a bevel might be better for speakers whose baffles are not recessed.

xschop

I agree and it makes sense that the non-recessed models have stronger baffles and indeed a beveled edge would be best for those.

My 5B's MDF seems stronger than the few sets of older 5Jr's that I built billet baffles for. I can't push as easily between MW and tweeter to make it flex inwards like the 5Jrs did.

However they would indeed benefit from a backing ring. I just mic'd a few stainless 8-32 hurricane nuts and what do you know, the thread depth is exactly 0.25"

Gardenstater

I believe MDF is better than particle board, at least density wise. I at first thought that my 7B's were MDF but nope, particle board it is. I am planning to try to increase the stiffness of the baffles, especially between cutouts, which is the weak point as you have correctly pointed out, by feeding slow curing penetrating epoxy in until it won't take any more. I did this on a scrap piece of particle board and it absorbed a tremendous amount.

I'll be very interested if you do a small production run of the steel rings, especially with a bevel. Too bad there's no way (?) to do these for the passives due to the stiffness, which is actually what makes them great potentially, but which would probably make them very difficult to get through the hole without permanently deforming them. The size of steel tube stock required would probably be cost prohibitive anyway. I suppose if it were feasible to make them, they could always be cut into 2 sections and would still be beneficial that way.

Keep up the good work!

hytekrednek

So sad they are not available anymore, but I do understand they are lots of work to make. Thank you Larry for making them for us. I got a complete set for both set of speaks I have, SDS 2.3tl and SDA CRS. I have not installed them yet, but plan to in the next couple weeks.
What drill bit size do I need again for the install?
Thanks again Larry. They are great.

GlennDog

agfrost wrote: »

Larry used to have a sweet video linked of rings being cut from sheet IIRC.

I learned what happens to them over time when I bought/didn't install rings into my RTA 11TL.



The painted ones have been installed in my 2BTL!

What’s the best way to clean-up rusty rings, prior to spray painting?

Asking for a friend 😂

xschop

GlennDog wrote: »

agfrost wrote: »

Larry used to have a sweet video linked of rings being cut from sheet IIRC.

I learned what happens to them over time when I bought/didn't install rings into my RTA 11TL.



The painted ones have been installed in my 2BTL!

What’s the best way to clean-up rusty rings, prior to spray painting?

Asking for a friend 😂

Spray can Rust Converter. The phosphoric acid converts the rust to a phosphate primer. Tough as nails.

pitdogg2

In military terms they call that "parkerized" yep tuff as nails





In all seriousness when mine did that I could wipe most of it off just with my fingers. A green scrub pad knocked off the rest.
I never did paint them, I'm sure they'll be fine for 20 or so years

GlennDog

Sweet . . . THX