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Warning.... Kappalite 3015 NOT designed for Bass!


skidder652003
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[quote name='Bill Fitzmaurice' timestamp='1380630582' post='2228069']
One would not expect Aston Martin to honor a warranty replacement claim should one drive it into a grove of trees.
[/quote]

It depends if the steering column snapped beforehand... I'm sure the insurance company would come knocking at their door pretty swiftish.

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well thats whats weird cos i promise you there was absoloutely no distortion, it just stopped midway through the gig while the "crappy" ashdown 15 kept on going (and still is BTW). I guess Ford Mondeo's arent fast or glamorous but at least they dont Fri88ing cost 10 times as much and break after 11 months!

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Guess Im sc*wed... :(
We have given you an explanation of the reason this driver has failed, and this is not covered under warranty.

There are a number of factors which have led to the failure, and it is not purely down to operating frequency or power. It is a combination of factors which has caused the driver cone to move further than its design limitations, which are specified on the website:

Maximum Linear Excursion (Xmax) 5.9mm
Maximum Mechanical Limit (Xlim) 11mm

The driver has been used BEYOND its designed parameters, and we accept no liability for the failure of this driver and we will not be providing a refund or a replacement speaker. [color="#666666"]1 Oct 2013 2:45 pm
[color="#000000"]From: [b]Blue Aran[/b][/color][/color] In answer to one of your other points, it is not feasible for us to list every possible application for such a product, and how it will perfom in any given situation. The information regarding a 5 string bass was purely as an example of how it might be possible to overload the speaker.

There are numerous possibilities, including the fact that the speaker simply was not compatible with the cabinet you put it in.

The failure has been caused by over excursion of the driver beyond its designed limitation, and not any manufacturing defect.

We have been selling and installing Eminence speaker for 18 years, and as a company we have over 50 years combined experience amongst our staff of using these products. It is very easy for us to ascertain what is and what isnt a warranty failure.

Anything that is a warranty failure is promptly replaced by us, and both Eminence, and their European distributor have 100% faith in us to do this to the point they allow us to disassemble and assess warranty failures ourselves as we have the skills in house to do this. In fact we have more experience an expertise in this that Eminence's European distributor.

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[quote name='skidder652003' timestamp='1380655076' post='2228594']
There are numerous possibilities, including the fact that the speaker simply was not compatible with the cabinet you put it in.[/quote]That sums it up. How did you choose this driver? There's far more to be considered than just inches and watts.

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Guest bassman7755

Interesting that there was a thread on here a while ago about how "easy" it was to just whack an upgraded driver in some commodity cab and thereby avoid having to pay big $ for a "proper" high end cab. Well this just demonstrate the folly of doing that. A cab and driver is a tuned mutually resonant system, a bit like the spring-and-damper system on a cars suspension. Having said that it might be possible to re-tune the cab to the new driver by adjusting the internal volume and/or the port area and depth but youd certainly need to run some equations.

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[quote name='bassman7755' timestamp='1380707873' post='2229172']
it might be possible to re-tune the cab to the new driver by adjusting the internal volume and/or the port area and depth but youd certainly need to run some equations.
[/quote]

don't need to run equations, its convenient to do so, but the cab can be tuned using rice grains and an adjustable frequency sweep. Its advisable to do this anyway, since the calculations miss out of a few factors and can be a bit off.

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[quote name='bassman7755' timestamp='1380707873' post='2229172']
Interesting that there was a thread on here a while ago about how "easy" it was to just whack an upgraded driver in some commodity cab and thereby avoid having to pay big $ for a "proper" high end cab. Well this just demonstrate the folly of doing that. A cab and driver is a tuned mutually resonant system, a bit like the spring-and-damper system on a cars suspension. Having said that it might be possible to re-tune the cab to the new driver by adjusting the internal volume and/or the port area and depth but youd certainly need to run some equations.
[/quote]

I think that must have been the post i read! :)

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[quote name='Mr. Foxen' timestamp='1380712949' post='2229281']
don't need to run equations, its convenient to do so, but the cab can be tuned using [b]rice grains and an adjustable frequency sweep[/b]. Its advisable to do this anyway, since the calculations miss out of a few factors and can be a bit off.
[/quote]

Please do explain! Never heard of that one. Will brown rice have the same effect as, let's say, a basmati?

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[quote name='Ghost_Bass' timestamp='1380720176' post='2229485']
Please do explain! Never heard of that one. Will brown rice have the same effect as, let's say, a basmati?
[/quote]

Lay the cab on its back, put rice grains on the cone so you can tell how much its moving, sweep the frequency going into it between 30 and 120hz (cab tuning will be in there, really should be between 40 to 60) and the bit where it moves least is the tuning as the port resonance loads it down. If the port is on teh back, this is a bit harder, need to have it a fair distance from the floor if so.

Edit: and regarding cab tuning in commercial cabs, its pretty much going to be in a limited range, with a Kappalite, you'll probably get more than the stock speaker, but there are still limits, and the stock tuning won't take full advantage of the better speaker.

Edited by Mr. Foxen
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[quote name='Mr. Foxen' timestamp='1380720703' post='2229495']
Lay the cab on its back, put rice grains on the cone so you can tell how much its moving, sweep the frequency going into it between 30 and 120hz (cab tuning will be in there, really should be between 40 to 60) and the bit where it moves least is the tuning as the port resonance loads it down. If the port is on teh back, this is a bit harder, need to have it a fair distance from the floor if so.

(...)
[/quote]

Great tip, thanks for the explanation :D

Learning something new every day!

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[quote name='Ghost_Bass' timestamp='1380720176' post='2229485']
Please do explain! Never heard of that one. Will brown rice have the same effect as, let's say, a basmati?
[/quote]

Light grain weight and high visibility are the main factors, I believe. Avoid cooked rice, especially sauced, or rice puddings, as they rebound less well... :mellow:

Edited by Dad3353
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I just bunged a kappalite 3015LF into an old Ashdown cab and used it for lots of gigs and practises over the course of a year with no problems.
Then I put the same driver into a smaller Flite cab, where it sounded even better and it's been in there about 3 years, again with no problems.
I never did any port tuning with rice, custard or anything else and it's the best sounding cab I've ever had.
I must've just got lucky.......... or perhaps it's about to blow!

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[quote name='skidder652003' timestamp='1380716307' post='2229373']
I think that must have been the post i read! :)
[/quote]

This one probably :) [url="http://basschat.co.uk/topic/190368-barefaced-compact-vs-b-stock-speaker-in-dodgy-ashdown-combo/page__p__1850862__hl__kappa%2015__fromsearch__1#entry1850862"]http://basschat.co.uk/topic/190368-barefaced-compact-vs-b-stock-speaker-in-dodgy-ashdown-combo/page__p__1850862__hl__kappa%2015__fromsearch__1#entry1850862[/url]

And by the way my Kappa is still going strong. Frankly I think you've been unlucky. I think that the majority of people out there in basschat land, who have replaced the speakers in their cabs, have had no trouble whatsoever. Possibly because (purely by accident) their cabs matched the required parameters of the speakers they bought.

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Actually I think Skidder has a point. About the way these and other speakers are advertised and sold.With all their experience Blue Aran are well aware of the popularity of these drivers as the pre-eminent bass guitar speaker of the moment. For them to say they aren't suitable for low frequencies is disingenuous at least. in any case 'full range' includes these frequencies.

These speakers are advertised as handling 450W and 900W music programme by Blue Aran with none of the qualifications which appear on the Eminence website, they are also advertised as being good down to 40hz. There are no notes on their advertising which suggest there are qualifications or conditions to this. Suddenly when there is a problem the amnesia about limitations which clouds their advertising department is swept away and they become Europe's unimpeachable experts.

I believe they have a moral duty of care towards their customers. They certainly have a legal one. It is not reasonable to expect every customer to know the intricacies of cone excursion. It is reasonable to think that a speaker advertised as handling 450W at 40Hz can handle exactly that, even though those of us with any technical will know that claim to be false and misleading.

I want Blue Aran to succeed, I have been a regular customer and in the past have recommended them. Recently I have found their customer service to be increasingly less helpful and less customer focussed. I hope they are following this and offer some help here. At the very least they need to modify their website to more accurately describe the capabilities of their merchandise.

Edited by Phil Starr
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[quote name='Bill Fitzmaurice' timestamp='1380630582' post='2228069']
+1. As is the case with any and all drivers it must be loaded into a cab that is compatible with its specs. If one is to push it to maximum output the amp must at the very least be appropriately high passed, if not limited to the driver's safe operating voltage swing. It must have sounded really bad for quite some time to have sustained the damage that it did. Distortion is the driver's way of telling you that you're pushing it too hard.
In terms of performance the 3015 is on par with an Aston Martin. One would not expect Aston Martin to honor a warranty replacement claim should one drive it into a grove of trees.
[/quote]

I like Bill's analogy with the Aston Martin, however to me in this particular context it would be a bit more like pimping up your Aston Martin by going to the nearest Car Parts Dealer, buying some random engine components and fitting them, and when the engine blows up, passing the blame to the car parts dealer for not teaching them how to be a mechanic.

In many cases it is possible to swap out a driver in a bass cab, and achieve good results, many drivers have a reasonable tolerance for being used in different cabinets with different tuning and the end results being without incident, this does not mean it will always be the case.

There are a few key points you should be aware of if swapping out a bass driver:

1. Box tuning, your cab will almost certainly be tuned to a specific frequency, the ports in the front baffle work to complement the driver for which the box was designed. Around the resonant frequency of the box, cone excursion is reduced, and there is an increase in bass output. Without going into too much detail, the resonant frequency of the driver should be appropriate for the cabinet design, a wildly differing resonant frequency to the original can cause undesirable results.

2. With a reflex box, it is strongly advised to use a high pass filter just below the box tuning frequency, so if your box is tuned to 55Hz, you would want a high pass filter, preferably 4th order, to remove frequencies 54 Hz and below. Why? It's one of the side effects of tuning a box, at resonant frequency and just above you get a reduction in cone excursion, but BELOW the box tuning frequency and resonant frequency of the driver you get a MASSIVE increase in cone excursion, therefore it is imperative to remove the damaging low frequencies.

3. Replace with a driver thats suitable for your application, whilst all 15" drivers are capable of reproducing bass frequencies, some do it better than others, and some 15" drivers are tweaked for bass heavy applications, some are tweaked for general purpose application. A general purpose full range 15 is usually designed for use in a 2-way system in conjunction with a HF devices to run in a box for playback of prerecorded music and/or live vocals, etc where there is a mix of bass and mid evenly spread across the frequency spectrum. General purpose 15s are usually not designed for bass only applications. In this instance it would bhe prudent to note that there exists a Kappalite 3015 and a Kappalite 3015LF, the LF signifying Low Frequency suitability. The 3015LF has a maximum mechanical excursion of 17mm against 11mm of the 3015, this is significantly more distance before the voice coil/cone reach their limits. It is also normal in a LF model to have a stiffer suspension, which can reduce the cone movement for a given level of input power. A very lightweight cone, with high sensitivity and lighter suspensions as found in the 3015 is more suited to mid and high frequencies, the lighter cone and stiffer suspension can move quicker and faster, usually giving a cleaner sound and less distortion in vocals and mid frequencies. However, a lightweight cone will also be very responsive to the dynamics of live music, and the twang of a bass guitar will send the cone flying forwards very fast to the point it can easily go past its mechanical limitations. So in this instance you should be aware there is a significant difference between the 3015 and the 3015LF which is more than just a serial number.

Edited by AndyKos
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Signs of overexcursion: In the picture you can see creasing just inside the edge of the cone, this is caused where the cone is trying to move forward, but the edge suspension has reached its limit and wont let the cone move any further, initially the cone will flex a little to accomodate the additional forward movement, but ultimately will crease and fold as the forward pressure overcomes the mechanical strength of the cone.

Edited by AndyKos
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Additional signs of overexcursion:

In the picture you can see where the coil former is breaking up from having hit the back plate of the driver, this is caused by excessive excursion towards the back of the driver. This is ultimately the cause of the driver failure, as the mechanical stability of the voice coil has been compromised.

Additionally it is possible to see blackening of the voice coil, although this did not cause the driver failure, it is very likely it will have failed to the thermal overload in the not too distant future. The blackening is where the enamel on the copper is overheating and starting to burn. Alll drivers are rated to a certain power when used within their intended operating parameters, using the driver within its mechanical limitations is part of this. The blackening is a clear indication that the duty cycle of the drivers movement has resulted with the voice coil being outside the magnetic gap for a considerable part of it's operation. Keeping the voice coil within or near the magnetic gap is a very important part of the cooling process of a driver, an overexcurting driver will be moving in free air instead of within the magnetic gap. Close proximity to the pole piece, and other metallic components in the magnetic gap is a critical to ensure sufficient cooling. If the voice coil is forced out of position due to over excursion, it can not cool properly. A DC Offset (amplifier fault) can also contribute to problems like this.

My conclusion is that the driver in these two pictures failed due to over excursion, most likely due to incompatibility with the cabinet in which is was being used. However in addition to this, significant power would have been applied in order to cause the voice coil to blacken.



Edited by AndyKos
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[quote name='gjones' timestamp='1380735011' post='2229781']
This one probably :) [url="http://basschat.co.uk/topic/190368-barefaced-compact-vs-b-stock-speaker-in-dodgy-ashdown-combo/page__p__1850862__hl__kappa%2015__fromsearch__1#entry1850862"]http://basschat.co.u..._1#entry1850862[/url]

And by the way my Kappa is still going strong. Frankly I think you've been unlucky. I think that the majority of people out there in basschat land, who have replaced the speakers in their cabs, have had no trouble whatsoever. Possibly because (purely by accident) their cabs matched the required parameters of the speakers they bought.
[/quote]

purely by accident may well be significant here. If you actually took a look at the level of science involved in trying to achieve perfect speakers and match them up with the correct cabinet to get the best possible results you would perhaps have some idea of the time spent designing speakers and why some speakers cost as much as they do. Doing the R&D on a new speaker design is labour intensive and can be costly, money that has to be recouped in the sale of cabinets.

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[quote name='redstriper' timestamp='1380734246' post='2229763']
I just bunged a kappalite 3015LF into an old Ashdown cab and used it for lots of gigs and practises over the course of a year with no problems.
Then I put the same driver into a smaller Flite cab, where it sounded even better and it's been in there about 3 years, again with no problems.
I never did any port tuning with rice, custard or anything else and it's the best sounding cab I've ever had.
I must've just got lucky.......... or perhaps it's about to blow!
[/quote]

Kappalite 3015LF is a much better choice than Kappalite 3015 for a bass guitar cab. The two drivers are quite different, and intended for different applications.

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[quote name='AndyKos' timestamp='1380831543' post='2231374']
Kappalite 3015LF is a much better choice than Kappalite 3015 for a bass guitar cab.
[/quote]

Not if you want some top and definition in your sound, and don't want to eq out a weird mid bump from using a driver outside its intended passband.

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well thank you all for the informative contributions everyone has taken the time to place on this post.
I've made Blue Aran aware of whats going on here and i hope they may take the time to reflect on whats been said.
I would hope that in time they might like to add a small caveat to their website about the importance of matching cabs to speakers for all us non techie types who assumed from advice given here on earlier posts that replacing speakers with upgrades wasn't a risky (and expensive) business!
For my part I don't think I'll go through all the hassle of a speaker replacement and it's associated risks in future and just get a 2nd hand cab with speaker from a well known brand on here that at least should be matched.
A bit bitter about the whole thing to be honest, as my ashdown and warwick cabs are still going strong, but hey ho, you live and learn. ... :rolleyes:

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