BillFitzmaurice.info

Does anyone have any experience with the eminence Lab 12ARK recone kits? The original driver is listed as 6 ohms, but the recone kits are listed as 8 ohm. Is this just a typo because eminence doesn't have a letter designation for 6 ohm drivers?

You'd have to ask the vendor why it's listed as 8 ohm when the LAB 12 is 6 ohm. If the picture shows what they're selling it's not a genuine Eminence LAB 12 kit, you can tell by the dust cover. It may be a kit they put together themselves.

Did you smoke one?

Bill Fitzmaurice wrote: ↑Mon Oct 01, 2018 1:13 pm You'd have to ask the vendor why it's listed as 8 ohm when the LAB 12 is 6 ohm. If the picture shows what they're selling it's not a genuine Eminence LAB 12 kit, you can tell by the dust cover. It may be a kit they put together themselves.

All the vendors I've seen list it as 8 ohms, I think it is just a typo because of the A designation, as opposed to the C one. Usually those pictures are just of "typical" recone kits, not the one you are actually buying.

SethRocksYou wrote: ↑Mon Oct 01, 2018 1:20 pm Did you smoke one?

Me? No. DJ's at the club while I went on holidays and nobody knows anything about it because it must of always been that way? 3 of them (not all at once).

edit: I wish I was there when they blew, they disabled the limiter so a full 97 volts were available to them until they blew. That must of been some crazy bass before silence came.

I'm going to be building some T45's for myself so I saved these thinking I can save some money by reconing them. I got them for nothing so worth a try.

I wouldn't give them the benefit of the doubt, I'd be sure before ordering. I assume LAB12ARK stands for Lab12A Recone Kit, but there is no LAB12A.

I just emailed Q Components (a Canadian driver supplier) and this was their reply:

"I spoke with Eminence directly regarding this. This was a typo from Eminence order book, but they confirmed it is a 6 ohm recone kit, not a 8 ohm. We have the 6 ohm recone kits in stock.
- Evan"

So it looks like they are indeed 6 ohm replacements, just labeled wrong.

Kinda neat, Q Components updated their website to correct the error within minutes of me emailing them. Every other website is still wrong

CoronaOperator wrote: ↑Mon Oct 01, 2018 2:26 pm

SethRocksYou wrote: ↑Mon Oct 01, 2018 1:20 pm Did you smoke one?

Me? No. DJ's at the club while I went on holidays and nobody knows anything about it because it must of always been that way? 3 of them (not all at once).

edit: I wish I was there when they blew, they disabled the limiter so a full 97 volts were available to them until they blew. That must of been some crazy bass before silence came.

I'm going to be building some T45's for myself so I saved these thinking I can save some money by reconing them. I got them for nothing so worth a try.

Sounds like "they" need 2 more in the heard. But then... is there really ever enough? Hahaha

I like your thinking about repairing them. Knock off an easy $300 from the build cost

SethRocksYou wrote: ↑Mon Oct 01, 2018 4:14 pm Sounds like "they" need 2 more in the heard. But then... is there really ever enough? Hahaha

I like your thinking about repairing them. Knock off an easy $300 from the build cost

EDM DJ's never have enough.

I since wired them series so that even if they disable the limiters:
A: only 1 would blow instead of both at once as that would open up the circuit (they are dual loaded cabs).
B: the amplifier only puts out 97 volts so each driver is only seeing around 48.5 volts - within their limits.

That has held up over a year so I think they are safe. If not, not my problem - we sold the club Sept 1st and they were too big to take with me so I left them there. I'm going to build single T45's so I can move them around more easily.

Ahh, got it. I was thinking the new owners smoked 'em. All makes sense now.

CoronaOperator wrote: ↑Mon Oct 01, 2018 4:27 pm
EDM DJ's never have enough.

I since wired them series so that even if they disable the limiters:
A: only 1 would blow instead of both at once as that would open up the circuit (they are dual loaded cabs).
B: the amplifier only puts out 97 volts so each driver is only seeing around 48.5 volts - within their limits.

That has held up over a year so I think they are safe. If not, not my problem - we sold the club Sept 1st and they were too big to take with me so I left them there. I'm going to build single T45's so I can move them around more easily.

Not that it directly affects you, but it's worth noting that this doesn't necessarily make you safe. When these idiots start redlining gear (which includes playing hard into the limiter so it's always limiting), they start driving the power curve up so you end up getting more power per volt. Bear in mind that when we do these equations for watts and volts and power there is an assumption that you are calculating RMS power. As you increase signal into a limiter or a clip point, the waveform gets squared off, meaning you get more power dumped into the driver without more volume. The effect is distortion of the signal.

On a graph power (watts) is represented by the area under the curve. This comparison shows a rather extreme example of this... but the type of example that would cause speaker damage in the situation described above. These two signals would show the same on a SPL meter, but they certainly wouldn't look the same on an RTA or sound the same. In this chart, the X axis is time and the y axis is modulation in volts. Power over time is represented as the area under the curve. Say these two snippets represent 1/50 second each, which would make this a 50hz sine wave. It is clear to see that the clipped signal delivers far more power (again, power is area) than the nonclipped signal at the same voltage.

This relationship of power to voltage and clipped signals is the source of the "underpowering blows speakers" myth. People will take a speaker rated for 500w, power it with an overdriven 400w amp, and end up delivering way more than 500w of power to the speaker causing thermal damage. They then assume that since their amp says "400w" in its specifications that 400w is all the power that amp can deliver, and wrongly assume that they have "underpowered" their speaker, and that killed it.

There's no such thing as idiot proof, reverse Darwinism is constantly refining the quality of idiots.

Excellent point on how peak limiters can lead to overheating of the voice coil if driven hard into them. I think they are still safe, all 4 drivers are being driven off 1 amp channel and I don't think the power supply of the amp has enough juice to drive all 4 of them into thermal overload. If they do I guess I get a service call
and more "free" baskets to recone .

BrentEvans wrote: ↑Mon Oct 01, 2018 9:34 pm When these idiots start redlining gear (which includes playing hard into the limiter so it's always limiting), they start driving the power curve up so you end up getting more power per volt.

I thought limiters left the signal intact. Like compression, attenuates signal peaks. No?