AudioKinesis Cabs V!!!!

[steve_rolfeca]

That is what Kjung is saying. But its just odd that a demension change will not change the tone.

Actually, it's not odd at all. Assuming that two boxes are equally stiff, if they both have the same internal volume, the acoustic damping material is applied correctly, and the ports are tuned to the same frequency, they will sound the same (assuming that the dimensions are kept within reason).

Duke has talked about the differences before, I suggest you do a search for compact and wide. IIRC, the wide was tuned very slightly deeper, but only by a couple of Hz.

Ditto for the wood and composite versions. There was some early discussion that there might be some differences, but since both boxes are exceptionally well-braced and internally damped, thee doesn't seem to be a consensus view of the difference, if one exists.

 

[Bassist30]

OK . So I guess ill assume there isn't any difference so Ill leave it at that. Enough people have said there isn't a difference. That it was basically done with amps in mind. Not a speaker cabinet maker maybe all of you are right. Doesn't really matter to me.

 

[Mike Arnopol]

I probably have more experience with both TC115 cabs than anyone. Duke has seen more cabs but I've played bass through them.

The difference between the wide and compact is slightly noticeable when a/b'ing them at home. Maybe somewhere between slightly and barely noticeable. On a gig I doubt that anyone would hear a difference. Maybe I have to goose the bass on the amp a half a click.

As far as the composites I think that Ken was right when he said that a little more care is necessary. I purposely don't keep mine in bags and beat the crap out of them. Structure wise if you took a sledge hammer the composite would hold up just as well as far as all of the joints. If you really bash an edge of the composite you might get a little chip but that's all. Easy to touch up with Duratex. And---the composite is easier to do a major repair to.

As far as the handles and corners---I have to disagree a bit. All of the corners are held in place with screws, neoprene washers and nuts. The handles have a 1/4" birch plate epoxied to the inside of the cab. And there are thick nylon spacers going through the composite between the handle and the plywood. The screws go through the spacers. This is so that all stress is on the handle and the Baltic birch on the inside. Because of the spacer the composite can't compress and none of the load is on the composite.And all machine screws and nuts on the handles also. The drivers are mounted directly to 1/2" baltic birch epoxied to the back of the baffle.

So--as far as the various components, I feel that the wood cabs hold no advantage. I do feel that if you get a composite cab you should definitely get a bag.While the durability is proving to be fine I also think that the wood cab has a slight edge.

Ken is also right about vibration.It's interesting---they don't resonate, though. It's simple physics---you excite something with a powerful motor---something of lower mass will react more. But with careful planning and manufacture these issues can be completely dealt with. Duke and I have redone the crossovers so that all components are hot melt glued and using wire ties. I now feel very confident on all of the internals---but it has been a learning process. I go INSANE using wire ties, Gorilla tape and hot melt on ALL internal wiring. To be perfectly honest---I tried out Ken's cab using my Doubler. Ken had a few rattling or buzzing issues and I redid his cab. I now realize that I have to test 15 inchers and up with a lot more power. No probs since.

Ken has been very kind in not mentioning the initial problems (all cab makers have problems with buzzes here and there---goes with the turf). But I feel it important to comment on how the evolution of the cabs has progressed. I have built double 12 and double 15 cabs with no problems---and I now pump the crap out 'em.

I'm just saying all of this to try to be honest and objective about my cabs. My goal is to always exceed expectations.


Oh---and Happy Holidays---it's been a gas dealing with y'all and I hope to continue improving!

 

[Bassist30]

Thanks Mike. Happy Holidays. A slight difference. OK. Sounds good. I owe chef a beer.

 

[KJung]

I probably have more experience with both TC115 cabs than anyone. Duke has seen more cabs but I've played bass through them.

The difference between the wide and compact is slightly noticeable when a/b'ing them at home. Maybe somewhere between slightly and barely noticeable. On a gig I doubt that anyone would hear a difference. Maybe I have to goose the bass on the amp a half a click.

As far as the composites I think that Ken was right when he said that a little more care is necessary. I purposely don't keep mine in bags and beat the crap out of them. Structure wise if you took a sledge hammer the composite would hold up just as well as far as all of the joints. If you really bash an edge of the composite you might get a little chip but that's all. Easy to touch up with Duratex. And---the composite is easier to do a major repair to.

As far as the handles and corners---I have to disagree a bit. All of the corners are held in place with screws, neoprene washers and nuts. The handles have a 1/4" birch plate epoxied to the inside of the cab. And there are thick nylon spacers going through the composite between the handle and the plywood. The screws go through the spacers. This is so that all stress is on the handle and the Baltic birch on the inside. Because of the spacer the composite can't compress and none of the load is on the composite.And all machine screws and nuts on the handles also. The drivers are mounted directly to 1/2" baltic birch epoxied to the back of the baffle.

So--as far as the various components, I feel that the wood cabs hold no advantage. I do feel that if you get a composite cab you should definitely get a bag.While the durability is proving to be fine I also think that the wood cab has a slight edge.

Ken is also right about vibration.It's interesting---they don't resonate, though. It's simple physics---you excite something with a powerful motor---something of lower mass will react more. But with careful planning and manufacture these issues can be completely dealt with. Duke and I have redone the crossovers so that all components are hot melt glued and using wire ties. I now feel very confident on all of the internals---but it has been a learning process. I go INSANE using wire ties, Gorilla tape and hot melt on ALL internal wiring. To be perfectly honest---I tried out Ken's cab using my Doubler. Ken had a few rattling or buzzing issues and I redid his cab. I now realize that I have to test 15 inchers and up with a lot more power. No probs since.

Ken has been very kind in not mentioning the initial problems (all cab makers have problems with buzzes here and there---goes with the turf). But I feel it important to comment on how the evolution of the cabs has progressed. I have built double 12 and double 15 cabs with no problems---and I now pump the crap out 'em.

I'm just saying all of this to try to be honest and objective about my cabs. My goal is to always exceed expectations.


Oh---and Happy Holidays---it's been a gas dealing with y'all and I hope to continue improving!

+1 That initial vibration issue was trivial, and you took care of it quickly and all is well. Zero issue there, and the additional stuff you put in your production (per our discussions) versus the very earliest cabs seems to have totally taken care of it. Since I got one of the very early models, I felt I was part of the 'testing out' process, and it seems to have resulted in a totally solid build!

The cabs do 'vibrate' a touch more at a very low frequency, and I have experienced some vibration inside a couple of heads that I don't hear with other cabs (this was actually the point I was making above, not internal cab vibrations, which are not an issue with your build). I found the same thing with my composite fEARful made by Aon. I think this is due to the composites vibrating at a much lower frequency. Minor issue, but just pointing out that these cabs, while sounding pretty much the same, do 'behave' a bit differenly.

I have had to tighten a few screws over the last 6 months (primarily on the feet) after lots of gigs and lots of cranking. Not an issue at all (I agree they are solidly attached, meaning they won't break, etc.), but again just pointing out that these cabs are just a bit different in how you have to approach them. Worth it to me, and I'm totally happy with it!

Again, just posting up these slight 'differences' with the composite build in the spirit of Bassist30 and my discussion over minor differences in all these builds.

 

[rpsands]

Composites are stiffer and should resonate at a higher frequency.

* Btw, pretty much every amp I have ever had has buzzed when on top of a cab without some kind of pad in between it. I use a poly foam mat from Costco most of the time.

 

[KJung]

Composites are stiffer and should resonate at a higher frequency.

* Btw, pretty much every amp I have ever had has buzzed when on top of a cab without some kind of pad in between it. I use a poly foam mat from Costco most of the time.

In 40 years of gigging, and 30 of those 40 years being a 'gear head', using many different head and amp combinations, I have only had the situation where something inside the head significantly buzzed three times:

- An awful 'Flite' cab, that was an early attempt at composite construction in the 80's.
- A fiberglass composite fEARful 15/6
- My composite TC115.

Other than these three executions, I have never used anything between the head and cab.

My guess that it was lower frequency resonance was just that, so +1 there. The key is, these cabs 'vibrate' quite differently than a wooden cab. They are a different thing altogether and are quite 'unforgiving' with anything 'loose' or 'buzz prone' sitting on top. Interestingly, I've had very light heads move around on the top of a wooden cabs before if I was really cranking the volume and low end, but no buzzing or rattling. Again, different dynamic going on there IMO and IME.

I LOVE my TC115 composite, and +1, on the heads that have the issue, putting any sort of padding under them (in my case, one of my F500 heads) totally solves the issue. Had a Genz Max 9.2 that didn't like the fEARful composite. Not a huge deal, but another indicator (again, in context to Bassist30's posts) of how the composite cabs are a bit of a different experience IMO and IME.

 

[Passinwind]

Composites are stiffer and should resonate at a higher frequency.

Yep, therefore they don't dampen lower frequencies quite the same way a wood cab does, unless you build in a mechanism to do so.

 

[KJung]

Yep, therefore they don't dampen lower frequencies quite the same way a wood cab does, unless you build in a mechanism to do so.

Ah, that is what I was trying to communicate. Makes sense. I was using 'lower resonant frequency' incorrectly to describe this, which would explain the bit more strain on closely placed components within some amp heads with these composite builds that also happen to wump out some nice low end.

Again, zero issue with most heads, and minor issue in the case of a 'buzz' issue that is easily fixed, as RPSANDS suggests, with some sort of minimal padding.

 

[astack]

I did some basic static flexural stiffness testing when I did my composite build (I'll post the data eventually). I found the composites were soft relative to ply. But because resonant freq goes like stiffness / mass, it ends up being an even trade. For DIY, I think I'm done with FG, but if I was buying something with the option I wouldn't hesitate. This stuff is TOUGH.

 

[KJung]

I did some basic static flexural stiffness testing when I did my composite build (I'll post the data eventually). I found the composites were soft relative to ply. But because resonant freq goes like stiffness / mass, it ends up being an even trade. For DIY, I think I'm done with FG, but if I was buying something with the option I wouldn't hesitate. This stuff is TOUGH.

The weight/performance ratio is stunning on the TC115 composite. Again, very pleased with mine, and the positives far outweight the few minor issues with the super-lightweight builds for me

 

[Passinwind]

Ah, that is what I was trying to communicate. Makes sense. I was using 'lower resonant frequency' incorrectly to describe this, which would explain the bit more strain on closely placed components within some amp heads with these composite builds that also happen to wump out some nice low end.

Hey Ken, all this esoterica depends completely on the specific composite build method. Most of my experience is with sailboards, where your ankles and knees become the damping mechanism if you get too carried away with making the composite structure really stiff. Compromises and tradeoffs, same as it ever was...

 

[rpsands]

So it's not that the panels are resonating at that frequency, it's that they're letting it all right through the panels into whatever's above?

 

[Passinwind]

So it's not that the panels are resonating at that frequency, it's that they're letting it all right through the panels into whatever's above?

Maybe, but also maybe there's just more lows coming from the speaker and/or port and exciting the amp. BFM used to reference this a lot in regard to the other direction, the floor.

 

[Mike Arnopol]

My experience sonicly with composites

Vibration and resonance are different things. As I said before---you physically excite something of lower mass and it will tend to vibrate more. So---even though the panel stiffness is high the mass is very low. So I think that the composite cabs can transfer vibration more than a wood cab.

Where I notice the difference is that---all cabinets resonate. We brace the panels to bring the resonant frequency higher. Problem is---when you you hit a resonant point on a wood cab it will "sing". Which is why we try to get those frequencies high enough that they are either inoffensive or can be damped with internal damping material.

With composite cabs they can be excited to resonance even more than wood cabs due to the low mass. But---my experience is that the foam in the structure damps the resonance so that the cabs don't "sing" I've found in A/B'ing wood and composite that the mid and upper bass are a bit more transparent. I think that this is due to the self-damping nature of the composite.

I think that there is a difference but it is subtle.

 

[Mike Arnopol]

So it's not that the panels are resonating at that frequency, it's that they're letting it all right through the panels into whatever's above?

I think so

 

[Mike Arnopol]

I did some basic static flexural stiffness testing when I did my composite build (I'll post the data eventually). I found the composites were soft relative to ply. But because resonant freq goes like stiffness / mass, it ends up being an even trade. For DIY, I think I'm done with FG, but if I was buying something with the option I wouldn't hesitate. This stuff is TOUGH.

The tests that I've done I found that the panels are very stiff in the overall deformation of shape of the entire panel in relation to force applied. I did find that the surface is slightly flexible---if you put a panel between two chairs and stand on it it will hardly flex at all. But if you press really hard with your thumb you can find a little "give".

So again---tradeoffs.You get less resonance but at least theoretically the panels can eat a little of the energy put in. The slight flex of the skin can theoretically absorb some of the energy that can be transferred into sound. But while I've heard that the composites have more bass clarity I haven't noticed any less impact of the bass energy.

 

[steve_rolfeca]

Ukiah Bass asked for plans to build the speaker stand I made for my TC 112AF.

I did it as an album in Photobucket, and thought other people might like it, if only as inspiration for something different.

The top is angled at about 10 degrees, which makes it easier to hear the yourself when standing close to the cab. The side panels are angled and braced with a center shelf, in order to stiffen everything up.

I swiss-cheesed the stand because I built it out of left-over 5/8" birch ply, which made it a bit porky. After drilling over 40 holes, the finished stand came out out at 8lb 9oz. It's very stiff and doesn't walk around, even when the TC is driven to max rated power on a bouncy, resonant stage.

On the plus side, it draws compliments. OTOH, I don't recommend cloning it, as the extra labour to drill the holes, touch everything with a roundover bit, and then sand all those edges, is just ridiculous...

If I was doing it over, I would have probably used a thinner ply for all panels except the base, and not bothered to drill them out. Not quite as stiff, I suppose, but much quicker to build.

Anyway, Merry Christmas!

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Steve R.

 

[Jazzdogg]

Well done!

 

[Bassist30]

Ukiah Bass asked for plans to build the speaker stand I made for my TC 112AF.

I did it as an album in Photobucket, and thought other people might like it, if only as inspiration for something different.

The top is angled at about 10 degrees, which makes it easier to hear the yourself when standing close to the cab. The side panels are angled and braced with a center shelf, in order to stiffen everything up.

I swiss-cheesed the stand because I built it out of left-over 5/8" birch ply, which made it a bit porky. After drilling over 40 holes, the finished stand came out out at 8lb 9oz. It's very stiff and doesn't walk around, even when the TC is driven to max rated power on a bouncy, resonant stage.

On the plus side, it draws compliments. OTOH, I don't recommend cloning it, as the extra labour to drill the holes, touch everything with a roundover bit, and then sand all those edges, is just ridiculous...

If I was doing it over, I would have probably used a thinner ply for all panels except the base, and not bothered to drill them out. Not quite as stiff, I suppose, but much quicker to build.

Anyway, Merry Christmas!

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Steve R.

Does look good.