kappa build problems

[cicatriz63]

Well i finally finished my kappa build a few weeks ago and wow, amazing is all i can say. Unfortunately while watching a movie one night i ran into some problems.

First off, i built mine using a kappa perfect 12.1 instead of a vq and the amp is an o audio in its own box. I had the gain at about 12 oclock and hi pass at 20 and while watching a movie one night i noticed this horrible cracking sound during loud boom booms. I took the driver out and noticed that the cone had separated from the spider, from what i could only assume would be from overextension. Luckily my dad had some good 2 part epoxy and we were able to reattach it good, and it works fine now. However when i tested it to make sure, during loud scenes i could tell the driver was struggling - even with the gain at about 11 oclock and the hi pass bumped up to 25.

Now granted, these drivers are probably at least 5 years old. even with it fixed good as new though it seems like its going to blow out again during certain scenes as i can hear the driver bottoming out. Am i just going nuts on the volume or is this just the limitation of using the 12.1? Granted it was fairly loud, but not unreasonably loud. Would it be worth just dropping the cash on a new vq?

 

[WmAx]

Well i finally finished my kappa build a few weeks ago and wow, amazing is all i can say. Unfortunately while watching a movie one night i ran into some problems.

First off, i built mine using a kappa perfect 12.1 instead of a vq and the amp is an o audio in its own box. I had the gain at about 12 oclock and hi pass at 20 and while watching a movie one night i noticed this horrible cracking sound during loud boom booms. I took the driver out and noticed that the cone had separated from the spider, from what i could only assume would be from overextension. Luckily my dad had some good 2 part epoxy and we were able to reattach it good, and it works fine now. However when i tested it to make sure, during loud scenes i could tell the driver was struggling - even with the gain at about 11 oclock and the hi pass bumped up to 25.

Now granted, these drivers are probably at least 5 years old. even with it fixed good as new though it seems like its going to blow out again during certain scenes as i can hear the driver bottoming out. Am i just going nuts on the volume or is this just the limitation of using the 12.1? Granted it was fairly loud, but not unreasonably loud. Would it be worth just dropping the cash on a new vq?

It sounds like the original glue was simply not applied correctly. I have noticed a large variance in some cases, in the application of the glue attaching the spyder. But even though you used epoxy to re-connect it, there may still be loose points deeper at the spyder/VC joint; the entire surface of the spyder slip on point and VC has to be generously covered with the adhesive to get a proper connection. I think the driver is going to have problems for now on. You can replace it with the VQ, or you can even upgrade and go with an extreme output driver, if so desired. The box will work perfectly with JL 12w7 driver, which has twice the linear excursion and twice the thermal power handling. If you find yourself using the sub at such a high output level that you are constantly exceeding the xmax by appreciable amounts, the JL driver is an option worth considering. The JL driver will get 2x as loud with equal SQ to the Kappa Perfect. Of course, the O Audio will never push the JL anywhere it's limits.

-Chris

-Chris

 

[lsiberian]

Well i finally finished my kappa build a few weeks ago and wow, amazing is all i can say. Unfortunately while watching a movie one night i ran into some problems.

First off, i built mine using a kappa perfect 12.1 instead of a vq and the amp is an o audio in its own box. I had the gain at about 12 oclock and hi pass at 20 and while watching a movie one night i noticed this horrible cracking sound during loud boom booms. I took the driver out and noticed that the cone had separated from the spider, from what i could only assume would be from overextension. Luckily my dad had some good 2 part epoxy and we were able to reattach it good, and it works fine now. However when i tested it to make sure, during loud scenes i could tell the driver was struggling - even with the gain at about 11 oclock and the hi pass bumped up to 25.

Now granted, these drivers are probably at least 5 years old. even with it fixed good as new though it seems like its going to blow out again during certain scenes as i can hear the driver bottoming out. Am i just going nuts on the volume or is this just the limitation of using the 12.1? Granted it was fairly loud, but not unreasonably loud. Would it be worth just dropping the cash on a new vq?

Another option is the Shiva-x from Exodus Audio. Still It's sounds suspicious where did you get the 12.1 from?

 

[just-some-guy]

i have/had the 12.1. low volume they are pretty good. high volume, not so much. these are fragile drivers.
my css are much better. and the shivas are comparable.

had i to do it again. 15's AT LEAST.

YMMV

 

[WmAx]

The SHIVA-X; while I'm sure it's a nice driver, I highly doubt it is anywhere near the performance level of the W7 unit.

The failure listed above is very unusual.

I have the 10" versions currently in use(I also have the 12" versions, but the are not being used right now), and 650 actual watts per unit can not over-drive them.

The Kappa Perfect .1 and VQ, it should be noted, have a very linear motor strength from 0, to well over the x-max point (14mm being xmax, I estimate 17-18mm where the motor is still retaining relativity high BL). But when you go past 20mm, into the mid 20 range, you suddenly hit CRITICAL FAILURE point. This differs from most subs, as most drivers start to audibly distort and have other problems well before they reach a point of critical failure, so you know to turn it down. On one hand, this is good, as the driver remains pristine SQ at even high level(most subs fall apart in SQ after medium drive levels), but it's also bad, in that you have no good warning to let you know you are about to destroy the driver. This is a common scenario with this driver when driven to mechanical failure.

But the above scenario, using only 450 watts, and a high pass protection filter, simply does not meet a scenario where the driver should have a chance to ever become over-driven to the point of mechanical failure. At 500 watts, with 2nd order 25Hz subsonic filter, in the avaserfi box, the maximum excursion I can calculate as possible is 14mm. With it set at 20Hz, the maximum is 17mm. This is radically under the mechanical limit, and well within the linear limit. Any problems at all here are due to DEFECTIVE driver or defective amplifier. And in this case, it's clear the driver is the problem due to poor quality control construction, assuming you purchased the driver new/unused. If it was used, then there is no telling how much abuse the driver could have been subjected to prior to your purchase.

-Chris

 

[WmAx]

i have/had the 12.1. low volume they are pretty good. high volume, not so much. these are fragile drivers.
my css are much better. and the shivas are comparable.

had i to do it again. 15's AT LEAST.

YMMV

Or you can go to 12" drivers with far higher output while retaining SQ, such as W7. A normal good quality 15" sub is not likely to match the output of a 12" W7 in the real world. The 8" W7 produces more output than most good quality 12" drivers in actual use.

As far as your statement that the 12.1 did not work well at high volume; under what conditions was this happening? Can you provide the actual SPL(and distance and room conditions), actual power supplied to the unit and the frequency and slope of the subsonic filter used? Was this the avaserfi design? I am simply curious.... thanks. Note: Haloeb uses on a regular basis, over 1000RMS per Kappa Perfect 12VQ(very similar to the 12.1, except the VQ has a variable motor design) with no issues (yet).

-Chris

 

[lsiberian]

The SHIVA-X; while I'm sure it's a nice driver, I highly doubt it is anywhere near the performance level of the W7 unit.

-Chris

Of course, but the Shiva models better than the Kappa Perfect VQ in the upper ranges. at 20hz they are identical. The 12.1 is also identical in it's max volume to the VQ as far as I can tell. I don't see it as an upgrade. The shiva would be better on higher stuff(than the VQ, but the 12w7 is certainly the better in that box.

It's too bad the Axis sale is over. That driver was less than the JL Audio 12w7 for a while.

But for 600 bucks you could get a single driver. 118db in that box at 20hz. Plus the mounting depth is shorter. He was talking 15" so I thought it would only be appropriate to suggest the 12" Axis. You can even make payments of 112 a month for it.

A pair of those would be extraordinary.

 

[cicatriz63]

Thanks guys, lots of info. Im not sure where the driver came from tbh as like i said they are at least 5 years old and have been in a car box the whole time. I think they were bought new off of ebay. I do have another one that i could use but ill wait and see how this one works first, like i said it works fine from what i can tell after the fix. I guess ill see if the second driver has any problems and if its the same ill just throw down for a new vq. A w7 would be nice if not overkill but i dont think i can drop that kind of cash right now hehe

 

[lsiberian]

Thanks guys, lots of info. Im not sure where the driver came from tbh as like i said they are at least 5 years old and have been in a car box the whole time. I think they were bought new off of ebay. I do have another one that i could use but ill wait and see how this one works first, like i said it works fine from what i can tell after the fix. I guess ill see if the second driver has any problems and if its the same ill just throw down for a new vq. A w7 would be nice if not overkill but i dont think i can drop that kind of cash right now hehe

I'd seriously consider the Shiva-X over the VQ unless you can get the VQ for around 180. They are comparable drivers. But the Shiva may be cheaper and has a bit more push it can take.

 

[WmAx]

I'd seriously consider the Shiva-X over the VQ unless you can get the VQ for around 180. They are comparable drivers. But the Shiva may be cheaper and has a bit more push it can take.

With only 450 watts available, he will not gain anything with the Shiva-X. The only thing the Shiva-X offers over the Perfect is more excursion capability; useful for sealed applications, but no advantage whatsoever in this guy's scenario. The VQ is typically available for well under $180; $180 (roughly) is typically the price WITH shipping. In the real world, much more power than 450 watts will not push the VQ to any danger zone. People usually use much more power than 450 on this driver for home use.

If the OP wants to go with an economical driver for sealed, then the Shiva-X woudl be a good option, but he should get much more than 450 watts, because substantial EQ is needed to get a flat LF response with sealed applications using these drivers.

But if a serious sealed sub is the point, I would go with something better than a Shiva-X. Maybe JL W7, or even a LMS Audio Pulse driver (you can still get 12" from Sound Splinter for $410 each; though these require massive power).

-Chris

 

[lsiberian]

With only 450 watts available, he will not gain anything with the Shiva-X. The only thing the Shiva-X offers over the Perfect is more excursion capability; useful for sealed applications, but no advantage whatsoever in this guy's scenario. The VQ is typically available for well under $180; $180 (roughly) is typically the price WITH shipping. In the real world, much more power than 450 watts will not push the VQ to any danger zone. People usually use much more power than 450 on this driver for home use.

If the OP wants to go with an economical driver for sealed, then the Shiva-X woudl be a good option, but he should get much more than 450 watts, because substantial EQ is needed to get a flat LF response with sealed applications using these drivers.

But if a serious sealed sub is the point, I would go with something better than a Shiva-X. Maybe JL W7, or even a LMS Audio Pulse driver (you can still get 12" from Sound Splinter for $410 each; though these require massive power).

-Chris

I hadn't thought about the fact he's limited by his plate amp.

Still his driver appears to be in great shape now.

Don't fix it if it's not broken. You will have enough headroom IMO.

 

[Tulsajj]

With the O Audio 500 watt plate amp, how high could you turn the gain up? I know the speaker could take 100% of the power but would that be hard on the amp? Is it recommended not turning a amp of that calibure more than 75%?

 

[lsiberian]

With the O Audio 500 watt plate amp, how high could you turn the gain up? I know the speaker could take 100% of the power but would that be hard on the amp? Is it recommended not turning a amp of that calibure more than 75%?

I suggest you put your sub amp at 50% and then calibrate it that way with your receiver. If you want to turn up the volume use the gains in your receiver instead of on the sub.

If your not getting enough bass. corner load the sub or do a crawl test.

I like corner loading. It gives a nice boost to the LFE.

 

[just-some-guy]

Or you can go to 12" drivers with far higher output while retaining SQ, such as W7. A normal good quality 15" sub is not likely to match the output of a 12" W7 in the real world. The 8" W7 produces more output than most good quality 12" drivers in actual use.

As far as your statement that the 12.1 did not work well at high volume; under what conditions was this happening? Can you provide the actual SPL(and distance and room conditions), actual power supplied to the unit and the frequency and slope of the subsonic filter used? Was this the avaserfi design? I am simply curious.... thanks. Note: Haloeb uses on a regular basis, over 1000RMS per Kappa Perfect 12VQ(very similar to the 12.1, except the VQ has a variable motor design) with no issues (yet).

-Chris

guys, i am out of the "loop" right now. i started my shower rebuild, and i am doing research/work on that. tile and plumbing forums are where i am at these days.

anyway

yes, those high end drivers would be nice, but are costly.

my 12.1 issues. they could take test tones well. but during movies, any good lfe would make em pop. at first they were great, but they went down hill. i am wondering if i wore out the surrounds, reducing their dampening,
or maybe i just overdrove them. idk

they were in the kappa build box's, kinda. i build mine a little narrower, and somewhat longer. otherwise the same. and box shape doesn't matter, Chris, you said so yourself(in another thread). so i highly doubt it was my box, specially since they worked good at first.

i had a inline HP @20hz. ep2500. pioneer vsx01txh.

btw. i now have REW. i set it up just before the shower rebuild. but have not done anything with it. i am renting not action movies for now, as to not get into any damage with what i have now.


so, if you will please excuss me. i have to go order my kerdi, so i can, hopefully, install that this weekend.

 

[WmAx]

guys, i am out of the "loop" right now. i started my shower rebuild, and i am doing research/work on that. tile and plumbing forums are where i am at these days.

anyway

yes, those high end drivers would be nice, but are costly.

my 12.1 issues. they could take test tones well. but during movies, any good lfe would make em pop. at first they were great, but they went down hill. i am wondering if i wore out the surrounds, reducing their dampening,
or maybe i just overdrove them. idk

they were in the kappa build box's, kinda. i build mine a little narrower, and somewhat longer. otherwise the same. and box shape doesn't matter, Chris, you said so yourself(in another thread). so i highly doubt it was my box, specially since they worked good at first.

i had a inline HP @20hz. ep2500. pioneer vsx01txh.

btw. i now have REW. i set it up just before the shower rebuild. but have not done anything with it. i am renting not action movies for now, as to not get into any damage with what i have now.


so, if you will please excuss me. i have to go order my kerdi, so i can, hopefully, install that this weekend.

That is interesting. I bet you liked to run you LFE pretty hot, over flat, too. I have specified in the past, describing the Kappa Perfect, in that it's linearity is also it's downfall... I'm sure you remember. It remains too linear, actually, in that it gives no obvious distortion or other sound problems when you are about to run it out of it's gap and mechanically destroy it. This is the most common failures I have read about, in fact. Most drivers have substantial distortions/noises well before you reach the point where you are about to damage them; so in this respect, the Perfect's motor is too linear vs. stroke, vs. the suspension system limits. The VQ has far less reported damage scenarios like this, and I suspect that the VQ's suspension was revised to take more abuse. This was one of my fears when other people started recommending the 12.1 over the VQ because the 12.1 was discontinued and could be found used for very good prices; so I always specified the VQ, personally. You can see my warning in the original avaserfi thread for the project when the 12.1 was initially brought up:
http://forums.audioholics.com/forums/showpost.php?p=504084&postcount=140

I reluctantly went along with this, as I have used them, but I also have warned in the past how they failed without warning due to the motor being too linear/capable vs. the mechanical limit, via a substantial number of reported failure cases in the car audio world. In any case, for very high SPL on a regular basis, I usually recommend drivers like JL W7, AP AXIS or LMS, etc.

-Chris

 

[jambam]

Hi I'm new here , and have been reading the thread on the kappa build for awhile and In fact I just completed one last weekend..

If I run the kappa w/out a 20hz HP filter but do not exceed 400 watts , am I in danger of damaging the driver?


Thanks

 

[lsiberian]

Hi I'm new here , and have been reading the thread on the kappa build for awhile and In fact I just completed one last weekend..

If I run the kappa w/out a 20hz HP filter but do not exceed 400 watts , am I in danger of damaging the driver?


Thanks

Yes you wil blow the driver.

Always use a subsonic filter.

Regardless of your power.

 

[lsiberian]

That is interesting. I bet you liked to run you LFE pretty hot, over flat, too. I have specified in the past, describing the Kappa Perfect, in that it's linearity is also it's downfall... I'm sure you remember. It remains too linear, actually, in that it gives no obvious distortion or other sound problems when you are about to run it out of it's gap and mechanically destroy it. This is the most common failures I have read about, in fact. Most drivers have substantial distortions/noises well before you reach the point where you are about to damage them; so in this respect, the Perfect's motor is too linear vs. stroke, vs. the suspension system limits. The VQ has far less reported damage scenarios like this, and I suspect that the VQ's suspension was revised to take more abuse. This was one of my fears when other people started recommending the 12.1 over the VQ because the 12.1 was discontinued and could be found used for very good prices; so I always specified the VQ, personally. You can see my warning in the original avaserfi thread for the project when the 12.1 was initially brought up:
http://forums.audioholics.com/forums/showpost.php?p=504084&postcount=140

I reluctantly went along with this, as I have used them, but I also have warned in the past how they failed without warning due to the motor being too linear/capable vs. the mechanical limit, via a substantial number of reported failure cases in the car audio world. In any case, for very high SPL on a regular basis, I usually recommend drivers like JL W7, AP AXIS or LMS, etc.

-Chris

well considering the price of the drivers I think it's resonably a good option. These aren't 200 dollar drivers. So in essence they are budget drivers. I've stated many times not to push the drivers too hard. They are the budget option for the VQ which is why I bought them in the first place. I must ask what type of filter you are using JSG.

I suggest using a Reckhorn, ED or DCX. For safety you can push the HPF up to 25hz. this is still comparable to most 1000 dollar and under subs. Make sure your HPF is a 2nd order filter. Also don't feed this sub more than 400watts. If you do that you will be fine. I suggest not turning your gains more than halfway on your EP2500.

I'd just save for a couple JL w7s if I were you JSG. Or save for a couple Axis 12"s

 

[cicatriz63]

That is interesting. I bet you liked to run you LFE pretty hot, over flat, too. I have specified in the past, describing the Kappa Perfect, in that it's linearity is also it's downfall... I'm sure you remember. It remains too linear, actually, in that it gives no obvious distortion or other sound problems when you are about to run it out of it's gap and mechanically destroy it. This is the most common failures I have read about, in fact. Most drivers have substantial distortions/noises well before you reach the point where you are about to damage them; so in this respect, the Perfect's motor is too linear vs. stroke, vs. the suspension system limits. The VQ has far less reported damage scenarios like this, and I suspect that the VQ's suspension was revised to take more abuse. This was one of my fears when other people started recommending the 12.1 over the VQ because the 12.1 was discontinued and could be found used for very good prices; so I always specified the VQ, personally. You can see my warning in the original avaserfi thread for the project when the 12.1 was initially brought up:
http://forums.audioholics.com/forums/showpost.php?p=504084&postcount=140

I reluctantly went along with this, as I have used them, but I also have warned in the past how they failed without warning due to the motor being too linear/capable vs. the mechanical limit, via a substantial number of reported failure cases in the car audio world. In any case, for very high SPL on a regular basis, I usually recommend drivers like JL W7, AP AXIS or LMS, etc.

-Chris

the 12.1 only has an xmax of 14.15mm whereas the vq is 16.75mm, so im sure this has alot to do with it. just doesnt seem like a whole lot of a difference, but im sure they must have beefed up some other internals as well (obviously just looking at the power handling.) Oh well, if i manage to blow this one i will just go for a vq or one of the other recommended ones. For now though I havent ran into any other issues with it, but its doubtful i will watch any action movies again without first turning down the gain a tad.

 

[lsiberian]

the 12.1 only has an xmax of 14.15mm whereas the vq is 16.75mm, so im sure this has alot to do with it. just doesnt seem like a whole lot of a difference, but im sure they must have beefed up some other internals as well (obviously just looking at the power handling.) Oh well, if i manage to blow this one i will just go for a vq or one of the other recommended ones. For now though I havent ran into any other issues with it, but its doubtful i will watch any action movies again without first turning down the gain a tad.

I suggest rasing the HPF to 25hz It will safely protect the driver from overdriving. IMO