No smoke... well..... maybe

Dra

Well to rehash my situation.
My Yorkville 400/800/1600w subs that were popping when receiving 750w of rap music but not loud because I moved the HPF from 45hz to 50 hz. I did as some at PSW suggested and planned to moved the filter down to 40hz because the majority of the sub content was in 30 & 40hz bands. I first found a song that had that bandwidth hitting and I did a 10 second loop of the boom, boom, boom, boom. No amp clipping and limiter set to hard limit with max peak (DR 260) at 78 volts (80 volts is max for speaker). Connected 1 speaker and brought thelevel up and then lowered the filter to 40 hz BW24. This added an amazing amount of increase to the output. Swept the filter back up to 50hz and down again. Did this for about 2 or 3 minutes, then plugged in the 2nd sub to the other side of the amp to make sure that it wasn't just 1 of them that was popping before. Both sounded great. Then I caught wiff of a sweet, but soured smell. :?
I turned down the music and the smell mostly went away. I thought the neighbors dog had dropped one nearby. Then at low volumes the music (only subs connected) was raspy / buzzy. It went away (mostly) as the volume went back up, but could tell that it was just masked a bit. Everything works but sounds horrible and the lower the volume the worse it sounds. :evil: :?: :?: I removed the grill and pushed the cone in. You could hear a sliding sound. Not a lot but like rubbing your finger on a table.

Obviously they are toast. Why?

Now... I obviously have to do something, because I have no subs (working). I am NOT under gun to resolve this, so I have time to discuss options. Money IS a factor. Recones will cost $400 (total).

These subs are used for primarily for 2 types of events. Middle & High School dances / proms / etcs, so rap music in gyms and ballrooms. The other events are corporate type events that include meet and greet background music, lots of speaking, and talent portions that include singing and dancing to tracks, some live instraments (usually acoustic guitar(s), piano, sax). I never foresee having to mic a dum kit or a bass rig.

So I am not asking much. Just sonically pure for the performance stuff, and loud and low for the dance stuff. The corporate stuff must look professional and low profile is a plus.

Options:
Recone the RCF's designed for the box ($400).
Replace with Yorkville B&C replacements ($620).
Replace with similar parametered drivers.
Buy new boxes.
Build new boxes.
Some combo of the above. This brings up a question. Is different design or driver size really a big deal for subs? Can output delay be used to match up wave fronts to work together?
4 cabs would be nice, if I can swing it.

Amps available for use:
Yorkville AP3400 (old 4040) 750w 8 ohm stereo (bridge to 8 ohm only)
Yorkville Ap3000 (old 4020) 475w 8 ohm stereo (bridge to 4 ohm - 2400w)
QSC PLX3102 600w 8 ohm stereo (bridge to 4 ohm - 3100w)
QSC PLX3102 - currently used for (4) 200/400/800w top cabs

HELP!

DRA

Gadget

Wow I'm STUNNED... $400 to recone? even JBL's aren't THAT spendy to recone...Where did you get a quote? What is the model # of those raw drivers? I KNOW I can get aftermarket kits for them for under $50, and with the model # I can see about the OEM ones...

As for the rest of your questions..
Too much power.. according to the guys @ PSW.. more than 2X the rated amp output was sent to the drivers. They say that the drivers can take square waves all day long WITHIN THE LIMITS of the driver.. you used too much power, OR you had the amp sending more than twice it's output rating...

As for new drivers there are benefits to that route.. ALL ceramic magnets loose strength when warm, and regain MOST after they cool..BUT all magnets loose their strength over time.. no ALL but some, Plus newer speakers have better tolerances...thus better specs, and better sound. As for the speaker being 4\" voice coil.. I'd like to have you measure the cone where it meets the spider...

Yes it's critical to replace the driver with something very similar spec wise...

If your adventurous, and a decent carpenter... you might consider reconing with the aftermarket baskets...selling or building another pair.. or building 4 of the Fane boxes I spec in the FAQ section...

Sorry for your loss..

G

fouronthefloor

Hey DRA.

We'll be setting up our rig tomorrow for some more fine tuning. I'll throw some rap at the subs to see how they cope. I'm sure that the two we have will cope well enough but I have a feeling that it'll take four of them to do rap music well. We're going to build another two as we still run out of bottom end towards the end of the night when we're pushing it and the room seems to eat up the low end. At the moment we're running two subs with 1500W each, and two SM15s that I've bi-amped, running 550W to the mids and 550W to the horns each. Anyway, I'll let you know what happens.

Robbo

Dra

$400 for the pair... but the email I had for the re-coner is no longer good. He was a garage guy that I found on the internet pretty much by mistake. The only quote I have back so far is for nearly $800 :shock: . I can get the new B&C's drivers for less than that shipped.

RCF L18/815K is the speaker in question.

I hadn't even considered copying these boxes, and getting them to match (grills and all) to the originals in a 100% lit room for all to see.... :?

What about my mix-n-match subs question? Could I make a pair of the 15\" (or 18\") Fanes play well with these \"manifold\" type 18\" if each is on it's on output from the 260?

DRA

Gadget

You know .. if those cones really are $75 I'd be willing to do it for $150 each max...plus shipping of course.. but lets see what Loudspeakers plus says...I'll get a Quote but they're closed for inventory till Monday... My recommendation would be no..they would be only ~ so so...together.

I just checked..and those kits are available... and $75 plus shipping...I could probably even walk you through re-coning them yourself...It's NOT that difficult...the only issue would be the glue and it's available...

G-man

Dra

Robbo, thanks.

Gadget, I thought that there was a special fixture required for centering the magnet.

DRA

Gadget

All you need is a shim of a given thickness.. I am constantly looking for materials.. sometimes ..gel material..sometimes packaging materials.. sometimes box like material.. thin cereal /potato chip box type material... that acts as a centering device is all that is necessary... some comes come with the shims..(Eminence) I bet if I got the cones from Jay @ Loudspeakers plus they he would be able to get the shim as well.. It's usually 12 3/8 \" long X 31/2\" long X .020 or so (thats the thickness of the one for the Eminence \"Omega\" 15 and 18\" woofers...) The thickness depends on the gap and fits into the center between the center magnet plate (metal.. not actual magnet) thats glued to the backer plate... the Idea is to get a fairly draggy friction that centers the spider and surround and holds them as the glue dries. It's important to be able to move the cone up and down (not freely...but with some drag) to assure centering and vertical position... but not difficult. The un-assembled pieces are more difficult, but those look to be ready to glue down.. the surround sometimes needs to be coated... but that is available too. I have a manual of not too many pages I could photo copy and email if necessary. Gimme a shout if you like we can talk about it.

G

Dra

http://www.simplyspeakers.com/speakerre ... ctions.htm
Is this similar to what you have (instructions)? It does not mention the shimming of the magnet???

After looking at these and seeing that they use 2 part epoxy, I recognized the smell I smelled. I've used a soldering iron to brittle-ize / melt epoxy when having to remove components embedded in it. It's burnt epoxy.

DRA

Dra

OK I think I get it. The magnet is not removed from the basket at any time. The shim is inserted on the inside of the coil (speaker facing up) with the center \"hub\" of the coil gap as the centering device, and is not in an area that is glued and is removed after the glue dries on the other side of the coil. I will be centering the coil to the magent, not the magent to the coil.

DRA

Gadget

Yes.. as it shows in # 4...and once the glue sets you pull the shim and glue the dust cap down....
and no the smell is the lacquer on the wire and the stuff they use to bond the wire to the coil former, and the former (usually kapton) or aluminum, but the aluminum ones don't stink as bad...

So you going to try it?
G

fouronthefloor

Only had a limited time to try rap through the subs but got some nice, low bottom end coming out of them. We had them stacked one on the other and you really probably would want two a side. Anyway good luck.

Robbo

Dra

I'm leaning towards reconing them, but still weighing the cost of building.


DRA

Dra

Is there a difference in the quality and power handling of the aftermarket cone kits compared to the factory's? Ever had a problem with them? Is the LS+ price with your discount? The reconekit.com price is the same. Is one factory and one not?

DRA

Gadget

Not sure I understand the question as stated... For one thing the aftermarket kits would probably be beyond your capability at this point since they are a cone (which sometimes even needs to be cut..) a voice coil, a spider, and a dust cap, not assembled like the picture on the site I sent you. You need to have the overhang factor which isn't always provided.

I have never had a problem with after market kits... I use them often on JBL speakers, as the kits for them are usually almost $200 my cost...Geez I love JBL :?

As for LS+ as I said I can't get to them till Monday...
G

Dra

Now I'm concerned. Cut? Over hang factor?
I found at least three sites with instructions. All slightly different, but for all practical... were the same and none mentioned any of these.

DRA

Gadget

The site I listed that had the cones all assembled for $75 each.. if you get the AFTERMARKET kits you get a cone.. a spider... a voice coil, and a dust cap.. they all have to be ordered separately... even the tinsel wires are not provided...all you get is a tinned end of the voice coil wire, and sometimes the cone needs to be cut to size as in some cones fit many different speakers by simply cutting the cone to length.

With the kits I speced for you you get original MFG, and all assembled, all you will need to do is center the voice coil, glue down the spider, and the surround, then the cap and gasket (looks like the gasket doesn't come with the kit?) (I can get the gaskets if needed and I have the tinsel as well)
G

Dra

I thought aftermarket just meant that is was made by a 3rd party. So I'll stay away from aftermarkets then, for sure.

From Reconekits.com that you provided...
Thank you for your contact. The McKenzie RCF L18-851/KN kit will also work for the RCF L18-851. We do not have any information on the L18-851/K kit. Yes all of the kits on our website come with shims, glues, instructions, etc.

Sales Team
www.reconekits.com


Thanks,
DRA

Gadget

DUDE your SET! I'd do that in a heartbeat...under $200... your back up and running in a day! IF... you were made of money...I'd get a new set of speakers since the magnets do loose gauss over time.. but I'd say they're still good for a few more pumps...even if you were a dealer like I am and could find a good substitute it would be double that for new drivers...

I wish you could have heard the system @ the Firehouse.. it was really something! The low extension when the building started to move...was absolutely UNREAL...When someone comes up in a panic and says...DUDE the FLOOR is MOVING!\" :shock: :shock: :shock: you gotta smile

You should have seen the expression on the bar owners face when I said I was building 2 more for the bar :shock: :shock: :shock: \"Ya right\"

Any way you look at it you need to get these back working and the cheaper the better.. THEN decide if you should sell them and make something new... or stay with those.

G

Dra

I'll order next week.
Any real world tips that aren't really in the instructions. Tools, cleaners, etc?

DRA

Gadget

BEFORE YOU REMOVE THE OLD CONE... make sure you check all the details... we will visit that later...Clean the gap with a piece of duct tape, or masking tape and make sure its debris free... Blow it out if possible with air...with the rasping the magnet wire will have rubbed against the outer gap and there will be debris...

Practice putting the shim in first and sliding the voice coil over it down into place....Put the glue for the spider on in a bead in the center of the raceway....then with the shim in place slide the cone assembly down till it touches the glue and flattens it out. **** MAKE SUR YOU ORIENT THE TINSEL LEADS TOWARD THE CONNECTION POSTS**** pump the cone in and out a few times pressing it well below the normal sitting point...it will spring back up (unless the shim is REALLY tight .. which has happened...try and get a centered surround on the upper casting and try and get the spider flat after you depress it. this will help make sure that the voice coil is perpendicular to the magnet structure... over the next few minutes insure that the spider stays down against the magnet raceway by pressing the spider against the raceway.. with a plumbing acid brush (you'll probably need at least 2) roll the cone edge away a little at a time and paint the surround glue under the surround... when and only when it's all covered, then go ahead and press it down.when it's all down, pump the cone a bit again to insure you don't hear rasping..(again.. unless its really tight) if not form time to time make sure the spider and surround stay down till dried.

allow to dry thoroughly... then pull the shim. Now take the cap and get it as centered and level as possible and then take a sharpie and mark that point for a place to put that cap back when you have put the glue on. Put a small bead of glue on the cap and place it carefully on the mark you just made. Glue the gasket down and solder the tinsel leads or crimp them depending on what they did.. WARNING... tinsel is a SOLDER WICK, so heat ONLY as much as needed and use only a very small amount of solder! Make sure BEFORE you remove the old cone that you pay attention to all the details.. how much slack is in the tinsel leads...did they bond the tinsel to the cone in any special way...compare the distance from the top of the ire on the voice coil to the spider and make sure its the same (the coil overhang...thats how much it sits above or below the pile piece.. thats the metal plate in the gap)

(note when pumping the cone try and do it near the bottom of the cone with equidistant pressure on at least two points... avoid bending the cone at all... if possible)

That's about it...
G

Dra

Solder: 60/40 OK?

Should the spider or surround glue \"expose\" itself on the edges? What diameter bead is best for these?

You mentioned before that coating the surrounds may need to be done. If they are pre-coated they will be very tacky, correct? If not what do I coat them with? Outside only?

I looked on YOUTUBE and was supprised that there were not any reconings there. There was a \"How it's made\" segment that was helpful to see the relative unconcern of the proccess, although it was sketchy (not all steps shown). Limited time due to the machining of the magnet and assembly to the basket.

DRA

Gadget

60/40 is fine, may be a crimp too...

Depends on the width of the landing, doesn't need to be just use enough to insure a good bond, but be sure the landings are CLEAN but NOT polished (in other words don't use a polisher).. just scrape it carefully with a razor blade or Stanley knife blade...

I would assume the surround will NOT be pre coated...for better bonding on the landing. Once the glue dries, coat only the top of the edge using the acid brush. I usually put the gasket on and paint all the way to the gasket to insure a good seal.. the stuff will be like clear rubber a single good coat is sufficient...

\" Limited time due to the machining of the magnet and assembly to the basket. \" HUH?

G

Dra

The entire surround and about an additional 1/2\" of the cone is coated with a shiny and still tacky substance on my currents.

The Discovery show \"How it's made\" did a start to finish speaker build. Sawing the iron plates, groving the coil gap, glueing and bolting the magnet assembly to the basket and attaching the cone assembly.
http://www.youtube.com/watch?v=VN0tmyyC ... re=related

DRA

Gadget

Ya well that was kind of an overview as you say, and yes your current speakers (currents? you guys and your internet lingo) would have that shinny \"rubber\" on there. But the one in the video was a foam surround.. yours will be a \"fabric\" \"waffle\" edge type that needs to be treated with the shinny clear rubber after the surround and gasket are in place. You will want to duplicate in EVERY detail what you see on your \"currents\" so try and save at least one as best you can.(the cone assembly that is) Take a sharp knife or razor blade and slice right at the basket frame and right against the landing of the spider this will allow you to measure the voice coil overhang if necessary. De-solder the leads at the terminals...carefully lift the cove out. you will now see the deformed inside coil former and baked voice coil...remember to clean ALL debris from the gap.
G

Dra

Hey Gadget,

Got the kits in. I need a 1\" brush for the surround treatment. What do you recommend? Foam, natural, synthetic?

Thanks

Gadget

well.. as I said I use acid brushes...the ones with the horse hair...1 inch isn't necessary, but it needs to be very very stiff.. I usually even cut a little off (at an angle using dikes) so they can be used to work the stuff in and smooth it out...no a foam one will not work...It is use it and dispose of it anyway... I'd go with the acid brush...you know the plumbers kind with the metal handle...
G

Dra

Gadget, email sent.

DRA

Dra

Finally wrapped the re-cones up and ran a sweep (30 - 3k) free air and they seem great. The entire process was easier than I thought originally, but harder than I thought before I started. Thanks to Gadget for the help.
I would not shy away from doing it again.

Of all the people on the forum Gadget is THE ONE.
Gadget you are da bomb. The ONE BOMB.

The Uni-bomber? 8)

DRA

Gadget

Awe Shucks :oops: (kicks at imaginary sand..oh wait.. it's MY house.. sand EVERYWHERE) just trying to help!
G

Dra

Well finally droppped the drivers in the cabinets today and fired them up. Warmed them up for a couple of minutes, then woke them up a bit. I never pushed them hard though. I will have my first gig that needs sub next week.
To be honest they sound a little raspy. Not like a rubbing coil, but like a heavy smoker. Odd. It could be that they are on casters and were on uneven ground. Maybe a caster was vibrating. I am probably hearing something that is not there.

DRA

fouronthefloor

When we built our subs, we bolted the casters to the box and there was a real weird, distortion emanating from the boxes. Fortunately it was the casters rattling. We took them the boxes and bolted them to a timber trolley that velcros to the back of the box. Problem solved. Hopefully this is all your issue is.