Bag End Speakers Are Weak

[Metal Mitch]

I'd be looking at the following:-

* Eminence Kappa 15c, 450w, tuned to 31Hz, -3dB at 75Hz.
* Beyma 15G300, 600w, tuned to 32Hz, -3dB at 73Hz.
* Eminence Kilomax 15 Pro, 1000w, tuned to 31Hz, -3dB at 49Hz.
* Beyma 15K200, 300w, tuned to 27Hz, -3dB at 62Hz.
* Eminence Kappa 15LF, 600w, tuned to 39Hz, -3dB at 47Hz.

Of these, the only one that can take 500Watts without hitting X-max is the Kilomax 15 Pro (600w). The next best is the Beyma 15k200 with 300w, closely followed by the Kappa 15LF with 279 watts. The Beyma 15G350 can only take 139w. The worst performer is the Kappa 15c with a mere 39 watts.

I haven't run any simulations on these. All this info is straight off Bgavin's excellent spreadsheet.

Yeah, the data is great... but "the crux of the biscuit" is knowing how to use it. So... how do you calculate power handling before hitting Xmax??

 

[Petebass]

Yeah, the data is great... but "the crux of the biscuit" is knowing how to use it. So... how do you calculate power handling before hitting Xmax??

I didn't calculate it, Bgavin's spreadsheet did. He's the master, I'm the apprentice. I only found all this x-max stuff out recently and haven't worked the nitty gritty out yet, but I will eventually. I didn't want to ask BGavin until I'd gone and tried to find the answer myself first.......

I do know this. You can use the new WinISD pro to calculate it. The have a new graph called "max power" which didn't mean much to me until the guys at Linearteam showed me how to interpret it. I had been using the "cone excursion" graphs without realising it wasn't taking into accounts the speakers non-linearity caused by the suspension and surround doing it's job. The max power graph does.

 

[PolkaHero]

Thanks Petebass, I cancelled my original order and have settled on an Eminence Kappa 15LF which I will order tomorrow from Parts Express as suggested by porcine. They're located in Ohio so it should be no problem getting the speaker by this weekend.

CB, I think the Bag End speakers are actually made by Electrovoice. Of course, I could be wrong. . .

 

[Petebass]

Thanks Petebass, I cancelled my original order and have settled on an Eminence Kappa 15LF which I will order tomorrow from Parts Express as suggested by porcine. They're located in Ohio so it should be no problem getting the speaker by this weekend.
:

Cool! Next step is to adjust the porting. You said the port is 5.5 inches in diameter.To tune to cab to 39 Hz, the vent will have to be 8.8 inches long.

Out of curosity, how long is the existing port? If it's longer, it's just a matter of cutting it down. If it's shorter, it gets a bit more complicated but it's nothing we can't manage.

 

[PolkaHero]

Ummm, the port is just hole in the back of the cabinet. There's no tube sticking inside or anything like that. I don't really think there's room to put a tube in as it would touch the speaker magnet pretty quick.

 

[Petebass]

Ummm, the port is just hole in the back of the cabinet. There's no tube sticking inside or anything like that. I don't really think there's room to put a tube in as it would touch the speaker magnet pretty quick.

We may have to get someone to knock up a tube out of PVC that has a elbow.

Have a look at the attachment. The green line is your frequency response with a 8.88in port. It's flat and smooth.

The orange line is your frequncy response with that speaker with the porting as is. I've assumed the timber is about 3/4in thick. See how there is an unruly hump at about 80Hz.

Quite frankly the green line should sound much better.

 

[PolkaHero]

Petebass,

I just discovered a cool feature on Parts Express where you type in the dimensions of your cabinet, impedance, etc. and the Selenium WPU1505 keeps coming up as the ideal speaker. It's not real pricey and handles 450 watts.

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Let me know what you think of this speaker. Thanks again!

 

[Petebass]

Petebass,

I just discovered a cool feature on Parts Express where you type in the dimensions of your cabinet, impedance, etc. and the Selenium WPU1505 keeps coming up as the ideal speaker. It's not real pricey and handles 450 watts.

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Let me know what you think of this speaker. Thanks again!

Interesting. I played through a custom made cab on the weekend that had the two of 12in version of that speaker. I liked it.

The 15 looks OK but it has a problem in the "max watts before x-max" departmant. The 12 actually outperforms the 15. The 15 is only good for 104 watts, the 12 was closer to 200w.

 

[BruceWane]

CB, I think the Bag End speakers are actually made by Electrovoice. Of course, I could be wrong. . .

Nah, they're made by Eminence to B-E's specs. You can tell by looking at the frame of the speaker - it looks like every other cast frame speaker built by Eminence.

By the way, there are reasons that some speakers are made with somewhat low power handling capabilities. High power handling requires a larger voice coil to handle the heat. Larger = heavier, which translates to lower efficiency (less volume per watt). So even though one speaker may handle a lot more wattage than another, it may only get marginally louder. So in $$$ per decibel total, you are often better off with a speaker that handles a bit less wattage and is more efficient, since the high wattage speaker will cost more, PLUS you gotta have the watts to drive it (bigger power amp = more $$$). Of course, there's situations when the high wattage stuff is the only way to get what you're after, but the lower wattage stuff (like your B-E's) definitely has it's place, too.

 

[BruceWane]

Interesting. I played through a custom made cab on the weekend that had the two of 12in version of that speaker. I liked it.

The 15 looks OK but it has a problem in the "max watts before x-max" departmant. The 12 actually outperforms the 15. The 15 is only good for 104 watts, the 12 was closer to 200w.

Careful with PartsExpress and their specs. I once found that they had reversed some of the specs between one of their 10" models and one of their 12" models, so the 10" looked impossibly good on paper and the 12" looked kinda crappy, which struck me as very strange within the same speaker line. Downloaded the PDF spec sheets and all became clear.

 

[Petebass]

Careful with PartsExpress and their specs. I once found that they had reversed some of the specs between one of their 10" models and one of their 12" models, so the 10" looked impossibly good on paper and the 12" looked kinda crappy, which struck me as very strange within the same speaker line. Downloaded the PDF spec sheets and all became clear.

I used Selenium's website so all is good.

It's not impossible that speakers will vary in quality within the same speaker range. Have a look at the Eminince deltalites. The 10's spec up nicely, the 12's and 15's are junk in comparison.

 

[The Clap]

I have a custom built Nahas cab with the 15" Eminence Delta Pro in it and it's fantastic (Highpass at 30Hz, lowpass at 700Hz). It is in a box that's a good bit larger than yours, however, maybe 60% bigger. You may like it, and it certainly won't sound bad, but you may be better off with a less efficient driver that can work in a smaller box like what you have.

 

[Brad Johnson]

I have a custom built Nahas cab with the 15" Eminence Delta Pro in it and it's fantastic (Highpass at 30Hz, lowpass at 700Hz). It is in a box that's a good bit larger than yours, however, maybe 60% bigger. You may like it, and it certainly won't sound bad, but you may be better off with a less efficient driver that can work in a smaller box like what you have.

I was at Joey Nahas' new shop yesterday. Very cool.

I use Bag End, Nahas and Euphonic Audio cabs. I'm just trying to imagine how loud Polkahero must be playing his BE 15 to damage it. I have an S15-D, a coax 15 and a 210 coax. Use all of them with some pretty serious fives and sixes, with 400 and 650w amps. One of my Nahas, a cab similar to an S15-D but deeper (18 x 18 x 18"), pumps hard with no signs of distress.