the term"power handling depends on application"

[king alpha 0]

I'm thinking about sending my blown 12" Adire Brahma MKIII to Scott over at Fi to get it reconed. Finding info on the MKIIIs is difficult. In fact, before Adire shut down, they had the MKIV in their current line up, and had a link to discontinued models. In that link, there's the Brahma MKI and MKII but nowhere was a MKIII mentioned.

Anyway, according to my research, the MKI and MKII is rated at 1,600 Watts RMS, and the MKIII and MKIV is rated at 600 Watts RMS. I can't find anything explaining why there's a 1,000 Watt difference between the MKII and MKIIIs but I don't have a problem with that. I've also read that the a Brahma (I'm guessing MKI/II) can reach full excursion from as little as 400 Watts, and as much as 7,000 Watts, depending on the application. I'm guessing it all depends on the box size and the MKIII should be able to take more then 600 Watts depending on the application. But I'm just guessing, so how do I figure out what "depends on application" mean and if it actually aplies to the MKIII versions?

Also, I can't find Adire's recomended box sizes for a MKIII but for the MKIV they recommend a .75-3.0 ft^3 @ 20-35Hz ported box. I already have a box that's 2.5 ft^3 @ 33Hz that was used for my Mag. If I used this 2.5 ft^3 @ 33Hz box, Can I feed the Brahma MKIII 880 Watts RMS (Massive P1000.1)? Or should I be considering more or less power to the Brahma?

One Last thing. Would getting it reconed by Fi change anything? I'm more concerned about power handling and box recommendations.

Edited July 24, 2007 by king alpha

[DevilDriver 28]

This is a perfect example of how much of an engineering company Adire was and how little of a customer company they are. Customers don't understand "intended application" (though in fairness, you do seem to have the general idea).

There are two primary considerations to a speaker's ability to handle power: 1. Thermal power handling, 2. Mechanical power handling.

Thermal handling has a lot of variables to consider, but the general idea behind RMS ratings is that this is the continuous power, with a decent crest factor, that can be handled by the speaker in all normal situations. Obviously, there are a lot of variations here that can change how much power can be handled thermally. For example, a BTL may be capable of handling 10kW for 5 seconds, whereas you might be pushing things if you are playing sine waves for an hour with 10kW on tap at full volume.

Adire's method of rating originally was an IEC (International Electrotechnical Commission) standard for measuring a coil's ability to handle power. The reason for the sudden drop to 600W Rms was a switch to a more conventional rating.

The "application" portion is largely considering the mechanical aspect. Mechanical limits are being reached when the speaker becomes damaged from coming in contact with other parts of the speaker (ie. coil smashing on back plate, bumping cone on spider, etc.). These limits are dependent on the excursion of the speaker, which varies with power, frequency, and enclosure size. If you increase power, excursion increases. If you increase enclosure size, excursion increases. If you decrease frequency, excursion increases. The inverse of these statements also holds true. So what Adire used to say was "this is roughly what the coil could handle...now whether you'll damage it mechanically or not will depend on how you're using it" and while this holds true for every speaker out there, it's not as easy for most customers to understand.

To answer your question, you should be fine. To a certain extent, almost any speaker can handle any power you throw at it for at least a little while, it's just important that if you hear or smell something you shouldn't, you turn the volume a little bit to the left. You should be just fine as long as you're not excessively aggressive, and that applies for every speaker out there.

Will the recone change the thiele/small parameters? Possibly, depending on the soft parts (big considerations are spider and surround compliance and mass of the assembly) but Scott should have a fairly good grasp on what's going in there and he can answer the question better than we can.

[Tirefryr 1,742]

Go to the Acoustic Visions section here. Kyle should have some info on the enclosure specs. I don't know if Fi will be able to do anything given the XBL^2, but Kyle will know for sure if anyone.

[Kyle Richardson 0]

Unfortunately, I dont have any information left from the MkIII's but if I remember correctly they were spec'd at almost exactly what the IV's were. Also, DevilDriver did an excellent job describing the different between electrical and mechanical power handling. Most users out there only know electrical handling and that is why the "power handling depends upon application" was mentioned because you can still kill a driver with many fewer watts than rated in an enclosure that will let it self destruct.

[king alpha 0]

Devil Driver: Thanks for the post. I really appreciate that. BTW, I posted about the Brahma in Realmofexcursion, and you replied there too. I remember the avatar. So, I was trying to find that post in here, until I realized it was a different site.

Tirefryr and Kyle: I just got back from visiting the Acoustic Visions part of this site. And reading that, I should just pick up one of those subs instead of trying to get mines reconed. Damn, now I got to think some more. ANd thanks for you info.

[DevilDriver 28]

Devil Driver: Thanks for the post. I really appreciate that. BTW, I posted about the Brahma in Realmofexcursion, and you replied there too. I remember the avatar. So, I was trying to find that post in here, until I realized it was a different site.

Tirefryr and Kyle: I just got back from visiting the Acoustic Visions part of this site. And reading that, I should just pick up one of those subs instead of trying to get mines reconed. Damn, now I got to think some more. ANd thanks for you info.

Since the Adire Audio branded products are no longer available, you might want to take a look at the Creative Sound Solutions SDX15. Kyle sells them; it's Tumult-esque at a very affordable price.

[king alpha 0]

Honestly, I'm not really looking for a "new" sub. I only have two cars. My brand new Rav4 will have the Mag that I will not get rid of. The other is my Mustang, which had the Mag in it, but since the accident (it got hit by an uninsured driver, who's also unemployed, so no money there), I haven't been driving the Mustang around. But when I do get the Mustang fixed, I still want a sub in there, and since I got the Brahma lying around, I thought I'd get that fixed. So, the only certain thing right now is the Mag going into the Rav4. A sub (new or old) in the Mustang is still up in the air and I thought I'd do some research to figure out what I want.