Failed speaker..????

[JTUK]

I thought I would throw this out there just to get a consensus
Whilst at a new gig last night I was struggling for sound from my normal rig.
SWR SM400 and 2xGS112. I never ever struggle for volume or bass in all the varied gigs I have done with this
set-up so I was thinking..jeez..this heavily carpeted room etc etc is soaking up a lot of volume.
I had no inkling of a speaker failure and only realised for sure when I set up to practise today and one
side of my amp did not work.
I traced this to the cab not working, eleminated the amp and the cables from the issue for certain.

I can't take it apart..just yet..as I think I have warranty on this so do not want to invalidate that, but my thoughts are
internal wiring, dry solder, etc etc ... and not blown chassis.. as no sound at all and no funny failing noises, whatever they may be..

Any other thoughts..?

I will of course, contact Aguilar ( have sent e-mail ) but just want a head start as I need to sort something out before next weekend.
I have a backup plan as well, but just touting for opinions..???

Any info or informed guesses welcome

Thanks.

[icastle]

If you've lost the HF output as well as the main driver then that could be a knackered x-over perhaps?

[JTUK]

ok, thanks. That sounds good thinking. There is no response from the horn or speaker but maybe the problem is before the reproductive chain of speaker/horn so jack, x-over or fuse if the device has such a thing.

[icastle]

[quote name='JTUK' post='1161210' date='Mar 13 2011, 11:39 PM']ok, thanks. That sounds good thinking. There is no response from the horn or speaker but maybe the problem is before the reproductive chain of speaker/horn so jack, x-over or fuse if the device has such a thing.[/quote]

Yeah.
If it was a blown speaker then I'd expect the horn to have carried on working.

The fact that the horn is dead as well is good news - it's most likely going to be a wire off on the jack/speakon -> xover area.
Can't find any mention of the Aguillar cabs using fuses, but keep an eye out for one if you decide to go delving...

[Mr. Foxen]

I asked aguilar about some stuff previously and there isn't a proper crossover, just the tweeter is high passed, at least in the GS412.

[JTUK]

Ok thanks, guys.

I have daisey-chained the 2 cabs with the U/S cab first in the chain and the second cab works, of course, which is why I didn't get the cab being out of action in a new environment.

I was assuming there was a fuse in the loop, but will have to talk to Aguilar guys to get any firther, I guess.

Many thanks

[JTUK]

Talked to the dealer who said by all means check out the back panel for wiring.
It is all very clean and tidy with clip-on connects mostly.

I plugged in the amp and turned the horn attentuator up on full...and I hardly get a sound from it but the signal does get through...and no sound at all out of the big 12".

hmmm

[icastle]

[quote name='JTUK' post='1162700' date='Mar 15 2011, 08:31 AM']Talked to the dealer who said by all means check out the back panel for wiring.
It is all very clean and tidy with clip-on connects mostly.

I plugged in the amp and turned the horn attentuator up on full...and I hardly get a sound from it but the signal does get through...and no sound at all out of the big 12".

hmmm[/quote]

I think I'd try and get a peek at the driver - can you see if the 12" driver connections are intact from the back panel?

Depending on how daring you're feeling, it might be worth bypassing everything and connecting your amp directly to the 12" driver - that'd give you an instant idea of whether the cab has to go back or if there's something daft going on with the existing wiring loom that you can fix yourself.

[JTUK]

[quote name='icastle' post='1163157' date='Mar 15 2011, 02:37 PM']I think I'd try and get a peek at the driver - can you see if the 12" driver connections are intact from the back panel?

Depending on how daring you're feeling, it might be worth bypassing everything and connecting your amp directly to the 12" driver - that'd give you an instant idea of whether the cab has to go back or if there's something daft going on with the existing wiring loom that you can fix yourself.[/quote]


All connections are good and solid... but could not get too much access to the driver through a pretty tiny opening for the attenuator plate.

I think unless it is a manufacturing fault..which would be hard to prove, this is down to me so I will take the thing apart myself and see if the speaker can take a signal.

But..I can't recall a time when this would have failed... as in slowly died and therefore you would hear that, I think.

[alexclaber]

How many gigs or loud rehearsals have you played with it? If it's quite a lot then it's most likely to be a blown driver as manufacturing faults or loose connections tend to manifest themselves early on. When speakers die due to thermal failure it tends to be pretty instant, unlike mechanical failure where you get increased distortion as the suspension is damaged and/or the cone creased. By gently pushing on the centre of the cone, just outside where the cone meets the dustcap, you'll be able to feel if the speaker is moving freely or if the voice coil is warped which then rubs on the magnetic gap.

[icastle]

[quote name='JTUK' post='1163285' date='Mar 15 2011, 04:32 PM']All connections are good and solid... but could not get too much access to the driver through a pretty tiny opening for the attenuator plate.

I think unless it is a manufacturing fault..which would be hard to prove, this is down to me so I will take the thing apart myself and see if the speaker can take a signal.

But..I can't recall a time when this would have failed... as in slowly died and therefore you would hear that, I think.[/quote]

Knew you wouldn't be able to resist it.

Thing is, if you were using two of those cabs at moderate volume then I'd guess you probably wouldn't notice it go down.

[JTUK]

[quote name='icastle' post='1163418' date='Mar 15 2011, 05:49 PM']Knew you wouldn't be able to resist it.

Thing is, if you were using two of those cabs at moderate volume then I'd guess you probably wouldn't notice it go down.[/quote]

I alway use as a pr in all but the quietest situations.


Funny thing is..we had a loud gig prior to this and all was well.

Then I had a another gig in another room with a quieter drummer and knew something was wrong but thought the room was very damp...
It wasn't until I got home and plugged the single speaker that I found out it wan't working.

So it is poss I didn't hear it fail at any one point. The other speaker is fine as far as I can tell..it is an older one, so bemused why one failed and not the other.

I have written off any manufacturer fault so I can now take it apart to see what has gone. When I can isolate what component has failed
I can set about getting a replacement part. By the time I have driven or sent the thing back to the dealer for warranty, I am into £40-50 of petrol anyway plus hassle, time etc etc .. I might just as well do as much groundwork as I can and get the part sent in ..

Failing that, I could just leave it for another day and buy in 2 DB112's if I can get them delivered for sat...hmmmm very very tempting, but I really shouldn't. Cheers all

[JTUK]

[quote name='alexclaber' post='1163415' date='Mar 15 2011, 05:49 PM']How many gigs or loud rehearsals have you played with it? If it's quite a lot then it's most likely to be a blown driver as manufacturing faults or loose connections tend to manifest themselves early on. When speakers die due to thermal failure it tends to be pretty instant, unlike mechanical failure where you get increased distortion as the suspension is damaged and/or the cone creased. By gently pushing on the centre of the cone, just outside where the cone meets the dustcap, you'll be able to feel if the speaker is moving freely or if the voice coil is warped which then rubs on the magnetic gap.[/quote]


It is 15 months old and I have had a few loud gigs recently...I run as a pr which enables me to get 400 in 4ohms from the amp. I would hope this is enough leeway.

I can't test the cone travel yet, but that is my next thing to do..

[LawrenceH]

I'd check it again with full-range music playing through the amp rather than a bass - cymbals will soon show you if the horn is working or not.
I'd also check the driver direct by unsoldering/unclipping any crossover and simply bunging a multimeter across the terminals set to measure dc resistance - should read somewhere around 5-7 ohms-ish. Probably easiest to access from the front of the cab and dropping the driver out, just don't put a screwdriver through the cone while doing it! Also be careful not to drop the driver when you take the screws out in case it yanks the cables off the back. I'd guess those drivers are reconeable if it turns out to have been burnt.

[LawrenceH]

Oh yeah, meant to say sometimes it is actually easy to make yourself believe there is signal from a horn, because when you put your ear up close it acts a bit like a seashell. Hence my suggestion to double-check with full-range signal, from an ipod into the amp or summat similar

[JTUK]

[quote name='LawrenceH' post='1163704' date='Mar 15 2011, 09:04 PM']I'd check it again with full-range music playing through the amp rather than a bass - cymbals will soon show you if the horn is working or not.
I'd also check the driver direct by unsoldering/unclipping any crossover and simply bunging a multimeter across the terminals set to measure dc resistance - should read somewhere around 5-7 ohms-ish. Probably easiest to access from the front of the cab and dropping the driver out, just don't put a screwdriver through the cone while doing it! Also be careful not to drop the driver when you take the screws out in case it yanks the cables off the back. I'd guess those drivers are reconeable if it turns out to have been burnt.[/quote]


There is very good cone travel but when I have tried to get any response from the speaker whilst out of the cab ..don't have a multi-meter to hand..so have concocted a speaker terminal connection, there is nothing.

So I suspect that the speaker has failed from a thermal failure as Alex suggested.

I will get it checked out tomorrow by a tech, to see whether the horn and x-over survive but it looks like decision time.

hmmm I hope I don't find a pr of DB's in stock....ha ha !!

[JTUK]

The 12" has an open circuit..which does not please me, although at least this is likely a component failure and not me putting too much through it.

So, need to source a Aguilar replacement or go for a Kappa pro 12A or Delta pro12A.
The word is that the nearest production model is the Kappa pro 12A but it has a bigger (80oz)magnet.

[LawrenceH]

[quote name='JTUK' post='1164358' date='Mar 16 2011, 01:10 PM']The 12" has an open circuit..which does not please me, although at least this is likely a component failure and not me putting too much through it.

So, need to source a Aguilar replacement or go for a Kappa pro 12A or Delta pro12A.
The word is that the nearest production model is the Kappa pro 12A but it has a bigger (80oz)magnet.[/quote]

Can you not get recone kits from Aguilar/Eminence? If it's a custom driver this might be the best way to make sure you get the same tone. The delta and kappa have quite different frequency response charts in the upper mids.

[JTUK]

[quote name='LawrenceH' post='1164514' date='Mar 16 2011, 03:22 PM']Can you not get recone kits from Aguilar/Eminence? If it's a custom driver this might be the best way to make sure you get the same tone. The delta and kappa have quite different frequency response charts in the upper mids.[/quote]


I am trying to get the Aguilar chassis as my first choice.
But there isn't much info forthcoming about how custom is custom and I doubt Aguilar or Eminence would be saying.
Others have asked and the info isn't out there. Talkbass don't know, for example.
I do agree that the simplest answer would be to slot in like for like.

[stevie]

[quote name='JTUK' post='1163770' date='Mar 15 2011, 09:51 PM']There is very good cone travel but when I have tried to get any response from the speaker whilst out of the cab ..don't have a multi-meter to hand..so have concocted a speaker terminal connection, there is nothing.

So I suspect that the speaker has failed from a thermal failure as Alex suggested.[/quote]

Thermal failure from overload would normally cause the voice coil to expand, which would make itself felt as a scraping noise when you move the cone in and out by hand. You can tell for sure if a speaker has been overdriven by looking at the old coil when you recone it.

If there is no scraping, there is a good chance that a wire or soldered joint has failed. It could well be worth having a chat with the distributor and sending the faulty driver back for replacement under warranty.

[icastle]

[quote name='stevie' post='1164669' date='Mar 16 2011, 05:33 PM']Thermal failure from overload would normally cause the voice coil to expand, which would make itself felt as a scraping noise when you move the cone in and out by hand. You can tell for sure if a speaker has been overdriven by looking at the old coil when you recone it.

If there is no scraping, there is a good chance that a wire or soldered joint has failed. It could well be worth having a chat with the distributor and sending the faulty driver back for replacement under warranty.[/quote]

+1
Absolutely agree.
When the voice coil gets hot it melts the shellac and allows the windings to slip.
Instead of being perfectly flat you end up with 'ridges' of slipped windings and resolidified shellac which is where the scraping noise described comes from.

A recone kit is all well and good, provided you have the facilities to fit it.
There's more involved than people tend to imagine as the cone kit has to be perfectly aligned before fixing into place - not something that most of us have equipment to do.

If it isn't scraping then there's a very good chance that the manufacturer will replace under warranty.

[JTUK]

I have had it looked at by a local qualified studio engr and he agrees that the chassis just failed as opposed to me just failing it. We have looked for loose cables etc but we think the failure is inside the coil.
Visually the speaker is perfect and the coil travel is free and silent.
I will try and send it back for inspection via my friendly dealer and see where that leads.
They would have to order a new one anyway through Aguilar.
As far as I know the warranty is 3 years and I have had it for 15months.

Thanks chaps

[Mr. Foxen]

[quote]The Eminence Delta 12LFA 12" Bass Speaker is recommended for professional audio mid-bass or floor monitor applications in a sealed enclosure. Specially designed with extended Xmax to deliver more bass than standard models. Available in 8 or 16 ohms. 500W power rating. Usable frequency range: 44Hz to 3kHz.[b]Eminence recommends the Delta 12LFA 12" bass speaker as a replacement in the Aguilar GS 112[/b] Accugroove Tri112SL and Behringer Eurolive B212 cabinets and the Ashdown Electric Blue 12 combo amp[/quote]

[JTUK]

Good post.

I hadn't seen that but had heard that the Kappa Pro 12 a and Delta pro 12a were the models pretty close to the bespoke Aguilar one.
The magnets are heavier and the GS is not a sealed cab but ported.

I have not had a reply from Emimence yet

[alexclaber]

The Delta12LF also works well in a ported enclosure for bass guitar, though it's a bit short on treble (but so's the stock GS112 driver!) The lack of voice coil / gap binding does suggest it's a case of bad luck rather than abuse, as does how it was being used (reasonable amount of power driving a pair of cabs indoors).