fEARful™ Part Twelve (12)

[cableguy]

^^^^^^ I don't think you blew the driver either. Sounds like a defective driver. I've had that much into my 12/6 and it handled it fine. I did have it distort a couple times with my 700RB-II really cranked and the 5 string button pushed. That really bumps up the low freq. Dailed the volume back and it's been fine ever since. It was really loud when this happened to mine.

 

[::::BASSIST::::]

I was also reading on the fEARful forum about loose crossover components causing distortion. I'll have to take the cab apart and see whats happening. It does sound like its coming from the driver though which leads me to believe its not the crossover, but I am not 100% sure of anything.

What's weird is that I have used this cab on a few gigs when I first got it and did not notice this distortion. So I guess its an issue that has just developed? If was a faulty driver wouldnt it be faulty from the beginning?

 

[BurningSkies]

There's definitely something not right. I say that because I run my fEARfuls LOUD. I'm talking BIG power per cab (sometimes bridged at 4 ohms with a 3Kw power amp, sometimes 8ohms a channel for about 500w per channel) and my 3015LFs are completely fine as is my 18 Sound 6.

For the past two weeks I've shared my bass rig with a keyboard player who throws a down-tuned Moog into it for the bass parts of his band (his upper keyboards handled by my Fender Twin at volume and a Mesa guitar amp). He's been HAMMERING it with sustained lows at high volumes and into the upper reaches of the mid speaker too. He's been amazed at the VOLUME and CLARITY he's been able to get and the gloves have been off.

Today I headed to our practice room and set up to survey if any damage had happened since Wednesday night's gig...to find that even running massive volume for sustained periods of time caused NO damage. And I was actually worried.

 

[geoff_in_nc]

If was a faulty driver wouldnt it be faulty from the beginning?

Nope... well not necessarily noticeably faulty at first. It would be a latent fault.

Take a look at the diagrams on Aperion University - How Speakers Work - Aperion Audio
The spider and the voice coil are very likely connected with some sort of glue/cement. If the glue joint is not up to snuff, it could come loose in action to some extent.

BTW: I have no connection with Aperion Audio, and have no idea if any other pages of theirs are riddled with BS or inaccuracies... these were just the first diagrams I found doing a search for "speaker anatomy".

 

[mntngrown]

Hmmm.... the glue I used on my build is really horrible stuff to work with (Bison Timbermax Express). Sticks to everything, doesn't seem to harden if it is too thick, foams up more than I expected with fairly large bubbles sometimes.

Anyway, the cab is together and I have started to round the edges and trim off the excess glue: Oobly - TalkBass Wiki

Scraping the glue in areas where it is thick and hasn't hardened in the centre makes the process rather messy! yech.

Is this the same way the proper stuff (PL Premium) behaves or is this stuff not a good match?

I have not built my own cab but have built several houses in the US. I see the PL premium at home depot next to/with the subfloor glues. In my part of the US that means putting a continuous bead of glue on the solid floor joist or manufactued I beam truss joist then laying plywood over it and nailing the ply to the joist. No bubbling involved. Talk to your local homebuilder or cabinet maker about a better glue if you can't access PL premium. Any "subfloor" glue should work.

 

[mntngrown]

There's definitely something not right. I say that because I run my fEARfuls LOUD. I'm talking BIG power per cab (sometimes bridged at 4 ohms with a 3Kw power amp, sometimes 8ohms a channel for about 500w per channel) and my 3015LFs are completely fine as is my 18 Sound 6.

For the past two weeks I've shared my bass rig with a keyboard player who throws a down-tuned Moog into it for the bass parts of his band (his upper keyboards handled by my Fender Twin at volume and a Mesa guitar amp). He's been HAMMERING it with sustained lows at high volumes and into the upper reaches of the mid speaker too. He's been amazed at the VOLUME and CLARITY he's been able to get and the gloves have been off.

Today I headed to our practice room and set up to survey if any damage had happened since Wednesday night's gig...to find that even running massive volume for sustained periods of time caused NO damage. And I was actually worried Very reassuring as I have not put major power through my 1515/66 yet.

 

[floydman]

I received my reliable hardware 15/6 grille in perfect condition thanks to the oversized, well padded box it came in.
It has no bends so it will be free floating, and I did not buy the mounting kit
I went to True Value and picked up 6 medium rubber stoppers which are almost the perfect height to hold the grille parallel to the baffle. I may be adding one flat washer to increase the distance by about a 16th. With a small hole drilled in the rubber stopper, #8 cabinet screws, and these nice looking black screw covers that were right next to the rubber stoppers I think it should be a pretty nice setup. When I get it installed I will post photos.

 

[BurningSkies]

I was also reading on the fEARful forum about loose crossover components causing distortion. I'll have to take the cab apart and see whats happening. It does sound like its coming from the driver though which leads me to believe its not the crossover, but I am not 100% sure of anything.

What's weird is that I have used this cab on a few gigs when I first got it and did not notice this distortion. So I guess its an issue that has just developed? If was a faulty driver wouldnt it be faulty from the beginning?

I know that Torin updated on Greenboy's forum, but not here. Once he pulled the speaker, he found that several of the mounting bolts/T-nuts had come loose, including at least one that fell out entirely.

 

[Coolhandjjl]

I received my reliable hardware 15/6 grille in perfect condition thanks to the oversized, well padded box it came in.
It has no bends so it will be free floating, and I did not buy the mounting kit
I went to True Value and picked up 6 medium rubber stoppers which are almost the perfect height to hold the grille parallel to the baffle. I may be adding one flat washer to increase the distance by about a 16th. With a small hole drilled in the rubber stopper, #8 cabinet screws, and these nice looking black screw covers that were right next to the rubber stoppers I think it should be a pretty nice setup. When I get it installed I will post photos.

Sounds like a great idea. Thanks!

 

[mikeddd]

I bought a new pair of metal shears and cut the lip and about a 1/4" of the front off the grill I got from Leland. All the vibration is gone! Seems that it was vibrating quite a bit more than I was hearing. Now the sound is so clear! I'll post some pics when I get home tonight. Flat grill is definitely the way to go.

 

[1n3]

Flat grill is definitely the way to go.

Glad it worked for you, but edge flanges add a lot of stiffness, so can be beneficial, especially when the grill material is lighter. Flange sides and edges don't have to contact the cabinet.

 

[Oobly]

I have not built my own cab but have built several houses in the US. I see the PL premium at home depot next to/with the subfloor glues. In my part of the US that means putting a continuous bead of glue on the solid floor joist or manufactued I beam truss joist then laying plywood over it and nailing the ply to the joist. No bubbling involved. Talk to your local homebuilder or cabinet maker about a better glue if you can't access PL premium. Any "subfloor" glue should work.

Thanks! That's good to know. Unfortunately my fEARful is all together now, only the grill standoffs need to be put in place.

I will certainly try to get something better if I build a 15sub to complement my 15/6.

Anyway, a word of warning to any European fEARful builder: DON'T USE BISON TIMBERMAX EXPRESS!

 

[mikeddd]

Glad it worked for you, but edge flanges add a lot of stiffness, so can be beneficial, especially when the grill material is lighter. Flange sides and edges don't have to contact the cabinet.

I agree. The grill is not as non-yielding as before. But, the material is pretty thick to begin with, so I'm not too worried. I don't exactly have roadies, so I'm not worried aobut someone manhandling the cab. The grill is plenty strong for the use it will see.

I'm just so stoked that there's no vibration at all. NONE.

 

[::::BASSIST::::]

I know that Torin updated on Greenboy's forum, but not here. Once he pulled the speaker, he found that several of the mounting bolts/T-nuts had come loose, including at least one that fell out entirely.

Yeah, I guess I should have posted here too. One was loose, one fell out completely. I just got home from Home Depot with some PL, that Robby recommended using. Hope I dont mess this up too much!

 

[BurningSkies]

Yeah, I guess I should have posted here too. One was loose, one fell out completely. I just got home from Home Depot with some PL, that Robby recommended using. Hope I dont mess this up too much!

You'll do fine. PL is easy to use, it's got the consistency of peanut butter. It doesn't surprise me that this happened, when I did mine I thought I had tightened my bolt enough only to find that the extreme vibration has loosened the bolts anyway.

 

[ian_s]

Some PL tips:

Wear latex or plastic gloves, at least until you get used to working with it.

I've found that if used within 15-20 minutes, antibacterial hand cleanser is good at taking it off your hands.

Cut the nozzle off at an angle.

When squeezing out a line of PL, stop squeezing a little before the endpoint, and release the pusher on the caulk gun, then lay the tube so the nozzle end is over some wax paper.

A nail is good for closing up the tube between sessions. I rest it so the nail head is resting against a wall or something heavy, otherwise the PL will push it out of the nozzle!

 

[::::BASSIST::::]

^ Some great tips! Thanks!

 

[rpsands]

Dude, you might regret using PL over the gorilla dropper for this application - the PL droppers alllllways dry out and the tubes don't seem to keep either. I hope it works out, but there is a definite advantage to gorilla glue for t-nuts. Also just seems to be stronger when bonding to non-wood stuff to me.

 

[::::BASSIST::::]

I actually did buy some Gorilla glue as well, but Robby did recommend the PL with the fibreglass and the PL tube lists foam/fibreglass as materials suitable for PL. In this particular case I think the expanding nature of the PL will be advantageous as the T-nut has too much space around it (which should be filled).

I guess I'll know soon enough.

Also, I am going to be building a 12/6 box in a month or so... so I'll need the PL for that anyway.

 

[rpsands]

Let me know if it keeps--mine didn't keep terribly well longer than a week or so.

Gorilla glue expands--you just get the surface wet. My preference for it is that it's much more precise, and is less likely to crack something by expanding by virtue of that. And that the little dropper keeps forever. Also, the thing it needs to stick to is the metal.

* here is what I use:
http://www.amazon.com/Gorilla-Glue-...D5EN/ref=sr_1_1?ie=UTF8&qid=1315882623&sr=8-1

** I recommend and use PL for building cabinets. Gorilla glue for small accurate stuff that you don't want to risk overapplying and metal. PL is terrible at adhering to metal.