Roy (Berryboy), question on the K-31

[Coytee]

How many screws are supposed to be holding it onto the motorboard?

Me thinks me has some buzzzzzzzzzing coming from a woofer.

I have SEVERAL things in the room (house [] ) that buzz so it's hard to be sure which buzz is which. When the Jubilees are playing however, that dx-38 has an interesting feature where you can kill one channel over another (not that you didn't know that [])

I killed both HF horns, and one LF at a time. Seems one of my bass bins has a buzz. I thought perhaps it was because it was vibrating against a wood floor (nope, I have a blanket under it)... perhaps rubbing against wall? nope... Well, perhaps it's buzzing because a support strut is loose? uh uh... Stick my ear on the front and it seems to be coming from inside?? yep. I even "lifted" to the degree I could, the Jubilee off the floor to isolate it as best I could... no help

Off comes the HF horn... good, only need a phillips to gain entry through the hatch.

Off come the screws on the tophatch. (didn't take any pictures for anyone)

Seems there are only four screws per each driver? (out of 8 possible??)

Also, seems these screws go into T-nuts and are not wood screws?

I reached my scrawny arm down there and indeed, at least one of the screws was noticably loose, so I tighted it up. 50% of the buzzing went away!!!

(that's the good news) The bad news seems that I likely have a screw loose on the bottom woofers underside & I'll need to take the bottom hatch off for that one.

So:

1. Does that seem reasonable that if one or two screws per driver loosen up, there will be some buzzing inside? (which is basically drown out when the HF horn is working) If not, where might I want to investigate?

2. How tight do these need to be? snug hand tighten? "HARD" hand tighten??

3. Since they seem to be machine screws, should I use some locktite on them?

4. Any merit in (trying) to add a couple more wood screws to the holes at 6:00 and 12:00??? (I think it'd be near impossible putting into other holes, absent removing drivers) those angles inside there, get in the way REAL quick.

I was surprised to see only 4 screws holding the drivers in, then again, I don't think I've ever paid attention to my LaScalas or (when I had them) Khorns so maybe it's common.

I've got someone coming over tomorrow to audition them, I'm glad I got most of the buzz out of it, however, it's still clearly there, just not as bad.

[] []

[colterphoto1]

Not wood screws if it's MDF, they'll never hold. Loctite sounds like good idea- which kind- that for 'assembled fasteners' that oozes in through the threads?

[cjgeraci]

Uh oh.

[Coytee]

Not wood screws if it's MDF, they'll never hold. Loctite sounds like good idea- which kind- that for 'assembled fasteners' that oozes in through the threads?

Surely the new company employee knows their flagship speaker is made from 3/4" seven ply furniture grade plywood? []

As for what kind of locktite, I have no idea. I DO know that I didn't notice any kind of lock washer (perhaps not needed since the gasket might keep pressure on screws?)

Regardless, since (between Mike & myself) I seem to be the one to turn them up to more violent levels, I really don't want the screws vibrating loose over time to be a recurring issue for me to deal with. I was going to call Mike & see if he had any known issues like that but got too busy cleaning the house up since the wife is gone to work. Maybe he's not had same issue since he uses that PP 2A3 as contrasted with my solid state.

What I find really interesting is I NEVER noticed it as long as the HF horn was 'honking away'. (for those who say horn speakers sound honky [] ) Even when I cut the HF horns out, I STILL thought it was simply more stuff in the room buzzing. (I've got a fireplace that vibrates pretty bad and loud at times).

Took me probably 30 minutes to finally decide my ears weren't lying to me and it was indeed, the speaker.

too bad I burnt the boxes up... I wonder if "tightening screws" is covered by the warranty if I had sent them back? [] of course, we won't get into how stupid it would be to pay a couple hundred in postage to ship these monsters back for a screw job.

(did that sound right?)

[:$]

[BEC]

They say a picture is worth a thousand words.

Bob

[BEC]

What would two be worth.

Bob

[colterphoto1]

I just wasn't sure about the motor board assembly. Sorry. I know better now. Just keep on 'alerning me, will you guys?

[Coytee]

Well, your 1,000 words just confused the dickens outta me...

I see something like 8 holes on the back, yet only 4 on the face...

Are some of the holes on the back "phantom" holes from a doubled gasket?? If the front of yours is the same as the front of mine (very likely I'd guess), then I obviously only have 4 THROUGH holes... I wonder why the back shows more or am I misreading something? (it IS dark inside that speaker)

?

[colterphoto1]

looks like the basket has 8, the gasket only the 4. Why o why doens't Klipsch bolt that sucker down with all 8?

[BEC]

Coytee,

The K-31Es I have came with some sort of metal mounting ring attached on the front that only has the 4 holes.  

Bob

[mikebse2a3]

Regardless, since (between Mike & myself) I seem to be the one to turn them up to more violent levels, I really don't want the screws vibrating loose over time to be a recurring issue for me to deal with. I was going to call Mike & see if he had any known issues like that but got too busy cleaning the house up since the wife is gone to work. Maybe he's not had same issue since he uses that PP 2A3 as contrasted with my solid state.

-----------------------------------------------------------------------------------------

Hey Richard

I've not had any issues like you have described.

Anyway if I can help just give me a call.

MAYBE YOU SHOULD BE KLIPSCH's OFFICIAL TORTURE TEST FOR THE JUBILEE's POWER TESTING!

mike tn

[WMcD]

Bob,

Many thanks for the photos. They sort of ease my mind on an issue.

I bought some Pioneer woofers which have a foam surround and low Fs for eventual use in a bass horn.

One of my concerns is how a very flexible surround will work when the units are used as a compression driver. Do the non rigid surrounds "oil can" when some pressure is built up?

BTW my use of the term "oil can - ing" comes from aviation wings where a thin, arched piece of a structure will flip from convex to concave. This is like the bottom of the tank used on an old time oil can where you push in to pump oil through the nozzle.

My first thought was the the accordion type surround which is integral to a paper diaphragm is no problem but a rubber or foam surrond might be. At least now I see that Klipsch uses a rubber surround.

Gil

[BEC]

Gil,

The K-31E certainly has a very low FS.  I measured 21 hz on the one I did the T/S testing on.

Bob

[bigdnfay]

The k-31 was also used in the KLF-30. The woofers were surface mounted from the outside. The pic above is one of those drivers. The outer ring is plastic and used to cover the raw edge of the driver(since you would see it). I ordered one for my Jub clone project and that is what i got. I noticed in one of the pics Roy posted of the factory build, a lady was gluing a second paper ring on the edge of a k-31 to be mounted to the interior of the Jub. Same driver, different rings. You most likely have dual paper rings and can use all 8 holes.

Big D

[homemadeheresy]

I have had success with coarse threaded drywall screws and MDF. First run them in, back them out, then apply some wood glue. This, of course, is on new construction.

[mark1101]

I remember that fireplace buzz......and some other occasional misc. house buzzing (glasses/dishes?).

I think that's funny. You damn near shook the Jubs apart Richard. I have to admit, you play it louder than anyone I ever knew.

Folks, I will say that I could hardly think of a tougher field test for any speaker than connecting it to Richard and his system. He PLAYS them, and plays them HARD. JC and I had to actually leave the room a couple of times. And I got the impression from the look on Richard's face that "that was nothing".

The first thing I did when I got your Khorns home was take them apart and tighten things up. As I remember, nothing was loose to speak of.

Just tighten those things up, and get back rockin'.

[Coytee]

I remember that fireplace buzz......and some other occasional misc. house buzzing (glasses/dishes?).

I think that's funny. You damn near shook the Jubs apart Richard. I have to admit, you play it louder than anyone I ever knew.

Ironic that you should say that as I've had others listen to them too and NO ONE (yet) when holding the remote, ever comes NEAR to the levels I tend to listen [:^)] [:^)] [:^)]

Folks, I will say that I could hardly think of a tougher field test for any speaker than connecting it to Richard and his system. He PLAYS them, and plays them HARD.

[:$] [:$] [:$] [:$] Guilty as charged your Honor...I drove my 1971 Oldsmobile 4-4-2 convertible hard too [6]

JC and I had to actually leave the room a couple of times.

Now THAT is where I found some humor...the volume would be on (for example) "3" and they'd be standing maybe 15' away. The volume went up to "5" and they'd scoot back to 20' feet away. I swear, it was really more like the volume control was a "forward/backward" command for them. Turn it down, they walked forward, turn it up and they stepped backwards. []

And I got the impression from the look on Richard's face that "that was nothing".

[A]

The first thing I did when I got your Khorns home was take them apart and tighten things up. As I remember, nothing was loose to speak of.

Just tighten those things up, and get back rockin'.

Did that but to get to the bottom two screws and make sure they're tight, I gotta flip one on it's backside. That of course, means removing the HF horn again, moving furniture, guarding my MC-2012 from being crushed... Truth be told, with the HF playing you really can't hear the buzz. It's greatly masked by everything else going on. Kill the HF horn though and the buzz stood out like Rudolph's nose!!

[jwc]

Richard. I mounted those K31's on my bass bin with the 4 holes. I have 8 available but as you said....4 only on that thick plastic rim.

I used a washer and a lock washer to keep the screws tight. I found that a few of my lock washers were duds and couldn't be used as they didn't line up right to "lock".

With as loud as you push them.......you may have to make another trip into that cubby hole at some point.

Are you still leaving the MC30's out of the mix? By the way, My sister dropped off my MC250 with Terry Dewick Last week. I gave him your name as someone who left him a good reference.

jc

[Coytee]

Richard. I mounted those K31's on my bass bin with the 4 holes. I have 8 available but as you said....4 only on that thick plastic rim.

Rigma came to audition them this last weekend. He happened to bring along a K31 he had, for me to see (because of this thread). Kind of interesting to me that they make it like that. RoyBoy told me that since it screws into the T-nuts, they don't need any more than 4.

With as loud as you push them.......you may have to make another trip into that cubby hole at some point.

Indeed... you've seen my room... not a whole lot of elbow room in there to lay a Jubilee on it's side/back and start opening it up []

Are you still leaving the MC30's out of the mix? By the way, My sister dropped off my MC250 with Terry Dewick Last week. I gave him your name as someone who left him a good reference.

I sold the 30's prior (I think?) to your visit. If not prior, not long after. When Keith bought them, he (having known of DeWick) asked me to take them to Terry so he could give them a once over since the two parties are so close to each other. To really make it easy/cool, we even went a step further where once I received the check, I told Terry they then belonged to Keith and Terry boxed them up and shipped them to him. Made it REAL easy for me!! Furthermore, Keith got them knowing that Terry had gone through them with a fine tooth comb AND has a lot of experience shipping these kind of things. Was a real win/win.

I know your sister is nearby, but just so I know it's said... (if Terry is shipping it back to you, ignore the rest)... but if you need someone to pick it up and hang onto it for a brief while (or much much longer? [A] ), his shop is about 5 miles from my office and I'd be happy to help out in any way I could.

jc

[mark1101]

Richard,

I know you have to move a lot of stuff and it's a PITA, but you're not going to do it? That rattle would bug the heck out of me.