With Power Comes Respect (Not Pretty)

[Bing Fung]

What a crappy night.... :M :M

After supper I decide I'm going to unwind a bit and play some music, SEAL IV on DVD-A.

Settle down to some music listening. So I'm getting into it and after 2 tracks, I start to push the system a bit hard to work out my kinks.... All of a sudden on Track 10 "Heavenly... (Good Feeling) I notice this Bass note that was simply awesome, but scared the SHIT out of me... I was impressed :twisted: But then in about 10 seconds later I hear another awesome bass note and then this loud BZZZ, BZZZ, BZZZZ




FUBAR'd

:M :M :M :M :M

Autopsy







I suppose with power you have to treat it with respect.

For those curious minds..

This was a home built sub based on a the Infinity Kappa Perfect Sub 12.1

Specifications
-Aluminum cone
-Singlel 4-ohm voice coil
-High-roll butyl-rubber surround
-Recommended power range 75-400 watts RMS
-peak power handling 1,400 watts
-Frequency response 18-200 Hz
-Sensitivity 96 dB

I was driving it with a Bryston 3B Bridged into Mono (~600Watts)

This thing sounded awesome, even in it's last moments. :twisted:

Added:

Another Forum member said it best...

With great power comes great responsibility :E

Thanks Bent!

[ThomasW]

Oops........ :cry:

-peak power handling 1,400 watts

Obviously not.

Before they disappear, grab a BP-1203 They can handle 1000 watts, and your 600 watt Bryston will play them to VERY high output levels.

[Bing Fung]

Hey Thomas!

Oops........ :cry:
Obviously not.

:laughat:

I don't know what I'm laughing at.... :nonod:

I plugged the Blueprint driver into Winisd. Based on it's calculations, it doesn't look like my enclosure is a suitable size. My enclosure is 110 L, My 4x15" port it doesn't like either..

Image not available

Blue = Blueprint
Green= My Kappa Perfect

What do you think, can the blueprint be tuned to this enclosure. I really can't begin building a new one right now.

[Sithlord]

Subwoofer

Bing stop playing with toys and buy an SVS B4+ :f>

[Bing Fung]

It's not an option right now Sith


Thomas, the Titanic driver looks like a fairly decent match, however the Port has problems... How critital is this? (Qes/Pe)

Image not available

[Bam!]

Bing! sorry to hear that man.....however Peerless makes great drivers.....Garreeeeaat!

[Bing Fung]

Thanks Steve, have a link?

[Andrew Pratt]

Peerless doesn't offer what you need. The titanic is a nice driver and appears well suited to your box as is...for the blueprint decrease the volume and see how it does...its easy enough to remove volume from your box just buy glueing in some wood blocks etc.

[Kevin P]

Bummer dude Bing. Looks like the voice coil overheated. I wonder if your amp was clipping and running DC through the coil during peaks. That's the only way I can think of where a 600 watt amp could toast a driver that can handle 1400 watt peaks. The other thing is, the recommended power range was 75-400 watts, so maybe 600 watts in a more continuous mode is too much for the VC to dissipate.

I would tend to lean toward clipping as the cause of death.

I'd probably try the Titanic next. Ports can be tweaked.

Oh, another question... on the Bryston, what's the power rating and minimum impedance, unbridged? When you bridge, you double the power but you also double the minimum impedance. An amp rated for 4 ohms minimum unbridged is only suitable for 8 ohms bridged. But if the Bryston can handle 2 ohms unbridged, you should be fine with 4 ohms bridged.

If the 600 watt bridged rating is into 8 ohms, with enough reserves it could have pushed up to 1200 watts into 4 ohms, enough to toast the driver if it clipped.

[David Meek]

Bing, that well and truly sucks. At least you are in the right place to get all the help you need, eh? Good luck fella.

[Bing Fung]

Andrew, I'll try the decreased volume for the blueprint. What about the "Qes/Pe" for the Titanic in the ported config?

David, you're right

Kevin, the Brytson is 122 Watts per channel (tested specs) @ 8 ohms. Bridged it becomes 244 watts (mono) Seeing as the Infinity driver is 4 ohms, that made the Bryston 488 watts (guess) as the Bryston doubles it power at the impedance changes. It is rated for 4 ohm bridged operation.

So it may have been clipping, however I don't suspect it was, as the LEDs on the amp did not indicate it was in clipping. Brystons Power LEDs switch from green to red when clipping occurs.

[Kevin P]

So we're talking roughly 500 watts into 4 ohms, bridged then. That shouldn't have toasted the VC. The driver got DC somehow, either due to heavy clipping or an amp malfunction.

Another possibility is the driver bottomed out hard enough to damage the VC. You would have heard a loud pop or clank in that case. Looking at the pics though, it looks more like the VC got too hot and deformed.

As for the Qes/Pe thing, I have no clue. Hopefully one of the speaker experts can chime in on this.

Can you get another Kappa driver?

[Andrew Pratt]

The reason you're seeing the error for vent air speed is that the PE value is zero in that input database so its trying to divide by zero which obviously results in an error. Any of the high xmax drivers are going to generate a lot of air movement though a single 4" vent even when flared so you may hear some chuffing when all hell breaks loose

[aud19]

Ouch Bing :cry: I'm sure the DIY twins, Andrew etc will be able to advise as to your best route though...

On a good note... It's kind of a "grunt, grunt" guy thing but in a way it's kind of cool that you were cranking it so hard you blew that %^%$ up! :twisted:

Jason

[Bing Fung]

Kevin, Im sure it must have got some wicked spike as thats what gave this gutteral wrenching bass that i have never heard before. :E :E :E I have to admit, I have been driving the system hard of late, and i just Boosted the Sub up +3dB just to see how it responded, I then backed it down to 0dB and hit the volume a bit harder :P

The Voice coil is loose from the sypder and from the cone. The pictures show it loose from the spyder, however it's totally broken from the cone as well.

Andrew, think it will be OK to run the Titanic anyway with the chuffing? Maybe the best solution is to get another Infinity Kappa driver for the time being?

I like the look of the Blueprint Driver and would like to use that, however I would have to build a new enclosure most likely, and if I was to do that I may as well start from the ground up and go 15". I just really can undertake that right now... ops:


Jason, your right, I have never blown up a speaker and this does serve as a Tim Toolman moment in some stranage way. "Arruh, Arruh, arruh!" :rofl:

[Kevin P]

That must have been some serious bassage to make the VC detach like that. Maybe it didn't clip/overheat after all. Maybe it's a weak link in the Kappa drivers, or a defect in your driver, or it bottomed out and broke off.

Port chuffing will only be a problem at high levels/high excursions, when a lot of air is going through the port. This will happen no matter what driver you use. The beefier the driver (higher Xmax), the greater the chance of chuffing being audible.

A friend of mine has a spare 12" driver out of an original SVS 20-39CS if you're interested. From what I've heard it has similar T/S parameters as the Shiva, so plug those into WinISD and see how well it would work in your box.

[Pat]

Bing, bummer about the driver...now you can build somthing really wicked :twisted:

From the pictures, it looks like the voice coil ripped away from the spider. :E
I guess the excursion was more than the poor little guy could handle

[David R.]

Looking at the infinity perfect in winisd, It's excursion power limit is about 300w's. I think you simply overpowered.. Judging from the damage in the cone (Voice coil pushed through the cone) it makes sense.

Think you need to find a sub that allows for more excursion.. stryke av12,dayton mk3,brahma is the kind of sub you should be looking at.. might need to re-tune the box with a new port maybe..

[ThomasW]

The overheated driver bottomed, that's the only thing that will shove a VC through an inverted (strong) aluminium dust cap

Bing.

Jon posted a Unibox sim of the 1203 in really small box. It's not very hard to convert your box to this design

[Bing Fung]

Kevin, I'll have to have a look at the SVS driver... Thanks

Pat, I wish I had the time to build a new enclosure. It really wouldn't take much effort now that I have the table saw, however I have so many projects that require my attention and building a new enclsoure shouldn't be one of them, however I very tempted Still I have to find a driver for my current enclosure. I can't just abandon it, even if I was to build a new sub wt enclosure. Your right though, the poor little guy just was hammered to death :cry:

David, thanks for your comments, I think your right, I need a higher Xmax driver


Thomas, that is one crazy graph. By the looks of it it looks like the driver requires a lot of power to keep a flatter response in the 35 to 20 Hz range. The port does a good job of bringing it all back up. I would have to take 40 Liters out of my enclosure, thats nearly 40% reduction required. I think I should / would build a new sub with a smaller enclosure and footprint if I was to use the Blueprint... Plus If I was to do that I would like to step up to a 15".

What about the AE Speakers (Stryke?) AV 12?

AV 12

It has lots of Xmax (23mm), tunes fairly well with my enclosure, and agrees perfectly with my current port length. It has a slight hump at the lower end, however I find that kind of desireable or I could maybe take that out with the Feedback Destroyer should it be too much. Plus it is less than 3dB difference.

Image not available

I just played that same DVD-A track "Heavenly" on Seal IV, it has a lot of bass even still on my system with out a sub. I can see how it may be a sub killing passage... At high volume levels :W

Is there a program that can be used to see (plot) the frequency profile of that track?

[Andrew Pratt]

The AV12's a nice driver too. The regular SV driver would be about $50US if he asks the typical asking price so its a good alternative to get you going again on the cheap but if you're bottoming out the Kappa the SV driver will as well so its not a long term solution for you IMO. I used the 1203 in Georges sub and for it I went sealed which elimitates the chuffing and still generates a great deal of SPL.

[ThomasW]

Bing.

You can easily decrease the volume of your box by simply putting rigid styrofoam inside it. Also you should just try it as is first.

As far as I know none of the AV series of drivers are actually available. John J is lining up investors. He needs $10K so as to buy $40K of materials since he's going to be building his drivers from scratch.

You'd need a MUCH bigger box for a 15". An example of an optimal design for a high excursion ported 15" is my AS-15 project. If you were to go with PR's instead of a port then the box size could be somewhat smaller.

All of these drivers are power hungery, but since you have 600 watts available that should be plenty....

Spectrum analyzer programs do what you want, here's a link to one

http://www.qsl.net/dl4yhf/spectra1.html

[Bing Fung]

Andrew, what amp did you attach to George's sub, I forget.


Thomas, there is always a catch isn't there....? :blink: Damn, I saw those AV 12s and thought, pretty near perfect...

So I take it then your recommendation is to get the Blueprint driver and work around it?

I'm not really crazy about stuffing my enclosure to reduce volume, thats going to be a lot foam blocks through the hole in front, but it may be worth a shot for a big Xmax driver.

Help me to understand something.. Why is it when ever I load these big excursion drivers into WinISD the roll off seem so high? The BP1203 rolls of @40hz with a vented enclosure. I noticed this when I was modeling the Stryke 15" Driver a year or so back..

Image not available

It's only calling for 15 liters, and nothing you do to the enclsure will extend the driver to the lover end. It only starts to spike the dB if you increase volume size. Are T&S specifications a numbers game for some makers?

Regardless, if you think thats the play in the end then I'll have to pull the trigger, as I need a driver now. There is only 2 drivers in the running, with the AV 12 not available. The Blueprint or the Titanic. The Titanic looks to be a better fit on paper.

[Bing Fung]

The site you linked Thomas has no international orders for the BP-1203. Where else could I find this driver?

[Andrew Pratt]

Bing the 1203 is available from Kyle at Acoustic Visions

As for George's sub I used the 1000 plate amp from Parts Express.

[Bing Fung]

right Andrew, thats the same site Thomas linked, however it states no International orders

7.Can you ship outside of the United States?
No. Because of continued shipping problems we are no longer accepting International orders. I'm sorry.

http://www.acoustic-visions.com/~acoustic/faq/

[David R.]

Bing, I think the titanic mk3 might be a good option.. Its excursion limit is around 550w's which fits your amp.. Might be cheaper to order this through acoustic-visions.. PE charges a ton of shipping to canada.

[Andrew Pratt]

Also how does this driver model in your box? SAE1204 The price sure seems right.

As for Acoustic Visions try calling Kyle and see what he'll do...he might be willing to help you out with a simple order to Canada vs something to europe etc.

[Bing Fung]

David, thats interesting, I didn't look at PE's shipping policy. They must be using UPS :M


Andrew, the SAE models very well. not as good as the Titanic or the Kappa, but pretty darn good for $110.

Image not available

I sent and Email to Kyle.

[ThomasW]

Bing,

The non-XBL^2 high excrusion drivers have a high LE (voice coil inductance) that rolls of their output usually above 70-75Hz.

I won't comment about WinISD plots there are issues with that program and I never use it

As you've noted the link I gave you was to Acoustic-Visions. It shouldn't be a big deal for Kyle to send a single driver up to Canada via USPS.

PE's standard shipping is UPS, that of course means high brokerage fees. I think they will ship USPS if specifically requested to do so.

Also you don't need to fill the box with little pieces of foam. Remember that a ported box is basically tuned to itself not the driver. I posted Jon's plot just as an example not something that needed to be exactly copied.

[Bing Fung]

Thanks Thomas, I think you have eluded to that about WinISD before when I was first building this first sub.

The non-XBL^2 high excrusion drivers have a high LE (voice coil inductance) that rolls of their output usually above 70-75Hz.

I'm not sure I understand the reference to that to the low end roll off.

I'm wanting the Blueprint Driver more, the more I think about it.. I would like to just drop it in and see how it performs. A la carte

I looked at your Arial Stryke Sub (Again), and I have to say again, your craftsmanship is amazing :E

I woul dlove to try and make something simular in the near future, although it would not have the nice cutouts like yours. Damn, you need to have a section of 1" Plexglass to show off all that great work.... :W

[ThomasW]

Stereotypically the issues with roll off is in the high frequencies with high exursion drivers.

Low end roll-off is just that these drivers have a higher Fs. And basically that's not a problem, since room gain fills in the lowest frequencies.

The cutouts in the AS-15 were done with a Jasper router jig, and a hand held jig saw. It was time consuming, but not technically challenging. Fortunately for me the photos are compressed so they hide a myrid of sins ....:wink:

[BrianJD]

Bing,

I have 2 new AV 12s in unopened boxes if you're interested.

[David R.]

The SAE1204 has similar propertys to a shiva (Might as well order from creativesound then).. Both have similar excursion limits as your infinity perfect, that being 300w's.. So while they would be good replacements, you may still blow them like the infinity at high volumes.

one of Brians av12 sounds cool, Or the dayton titanic MK3.

[Bing Fung]

Thomas, we are always our own worse critics hey? :W

OK, I understand what you are saying now about the XBL^2 drivers. I realize now thats a motor structure... I was not understanding it's context.

The high spike @40hz and then total fall off still has me a bit hesitant. WinISd may not be perfect, but it can't be that off, can it?

I contacted Kyle and he sid he would ship to Canda, however he will only ship UPS. That's a bummer, but at least he'll ship.


David, I looked at the Creative Sound, they are in Canada and they sell Adire. I modelled the Brahma driver and it looks pretty good in my enclosure. Takes a ton of power and has the XBL^2 motor structure Thomas was refering to. Now if only they had them in stock... I sent an e-mail asking when they may have them.


Brian, you've got mail.

[David R.]

Bing, Have you checked the cutout and outside diameters of the sub(s).. Need to make sure it fits in your hole , and the flush recess

[Bing Fung]

David, no I haven't, I assumed most would be standard, however that could be a minor problem on the recessed mount if the diameters are off.

The internals bracing, I could just insert my handy dandy Rotozip and carve to fit. :P

These are Autocad drawings I made when I designed the sub. It shows the internal bracing. It looks to have room, and I can check them, however internally should not be a problem. The face plate could be a minor annoyance if the recess diameter is not large enough. Or look funny if not deep enough.

Currently the recess cut-out is 12 .25" dia & 0.75" deep, Actual hole is 11"





Thanks for pointing out a possible overlooked issue :T

[Bing Fung]

Looks like the Brahma is 12.5" Diameter, with a cut-out diameter of 11.125", depth of 7.25"

I'm a bit shy on the diameter by about .25" and 0.125 on the actual hole :M

Sheesh, they don't leave a lot of perch if the cut out is to be 11.125 and the actual bolt pattern is 11.5"

At times like this I think I should just slide another Kappa into this and call it even, just be careful at the high end.....

Then really design and build a "New Sub" from the ground up :unsure:

[aud19]

:lol: You knew it was coming. We knew it was coming. You know you want to. We know you want to. Don't fight it Bing, just build the new one. :lol:

[David R.]

instead of another perfect (Which is a slightly pricey car audio sub, about 400 retail?) i suggest just picking up a shiva from creative sound, there 150.00 bucks. It matchs your hole size perfect, 11" cut out, 12.25" recess, 3/4" deep. Nice fit!.

It seems to match your current enclosure size/tuning good as well. Its excursion limit is similar to the perfect, but its also more efficent so you might just be ok at your listening level..

Only thing is the shivas ugly compaired to your perfect. LOL

cheaper solution tell you build a new one, IF you need to.

[Bing Fung]

Ha, you're funny Jason, I still need to fix this old busted down joint ans have it working, while I design and construct the new one :W (if thats what i'm going to do)

David, you're right the Shiva is ugly compared to the Kappa. I can buy the kappa for about $200 to my door off Ebay. Thats where I got my first one, however at the time the exchange rate was high as ws the price of the 12.1 Kappa Perfect.

They have the New Kappa VQ (Variable Q), it does not model as well as the original 12.1 Kappa, however it has about 50 watts (400) more power handling. I found out my Kappa was only 350w Continuious and not 400W as I thought.

Image not available

What would be a win / win situation is to buy one of Brian's AV 12 (provided it fits), for the time being. It's high excursion, models well with my enclosure.

[BrianJD]

Bing, you got mail.

[Bing Fung]

Thanks for the response Brian.

[Bing Fung]

Andrew or Thomas, do any of you know the size of the 1203 and if it will fit into my enclosure's hole?

Recess cut-out is 12 .25"
0.75" deep,
Actual hole is 11"

Thanks,

Looks like it coming down to the 1203 and experimenting, or the Titanic for plug and play ease. If I go the Titanic route I'll look to redesign a more powerful sub in the future.

[Andrew Pratt]

Sorry I don't have that info any longer and I can't seem to find it online either. Kyle should have it handy though. between the titanic or blueprint I'd go for the blueprint and adjust the internal volume a bit...at least then you'd know you'd be safe xmax wise and you'd have a nice driver to play with later if you did decided to try a new box (which would be very small)