AudioKinesis Cabs Part VI...

[Kirk Bryant]

Wait....did I just taste something funny in my coffee........

 

[Basically Bob]

I have had one of the original compact TC115 (composite) for several years now ... love that thing. It handles anything I do on its own quite nicely.

Just wondering if anyone could give me an idea of how its volume would compare to a new C1533?

 

[DukeLeJeune]

I have had one of the original compact TC115 (composite) for several years now ... love that thing. It handles anything I do on its own quite nicely.

Just wondering if anyone could give me an idea of how its volume would compare to a new C1533?

The Changeling 115 is generally louder than your TC115 but has less bottom end. In particular, the Changeling has more going on in the upper-mid region, ballpark 1.4 - 2 kHz, with the bottom switch in the "up" position. And from up close to the cab, you can hear your overtones better with the Changeling's open-format mid chambers.

So if we compare their tonal balances, your TC115 will have more energy south of about 200 Hz relative to the rest of the spectrum, and especially so from about 100 Hz on down.

If we compare how loud the cabs actually are, your TC115 will be about 1/2 dB louder from 100 Hz on down, but then north of about 200 Hz, the Changeling 115 will probably average about 2.5 dB louder.

The "in the pipeline" Tall version of the Changeling 115, which will be 31 inches tall instead of 25 inches tall, results in pretty much equivalent actual loudness below 100 Hz, so it has a slightly bigger bottom end than the normal version.

Subjectively, I always felt like the bottom end on the first-generation TC115 was a bit loose unless you plugged two of the ports. In fact that observation is one of the things that made me think I could get away with the higher efficiency, less-bottom-end Kappalite variant that I'm using now. All ports open on the Changeling 115 and Changeling 115T are reasonably close to 2 ports plugged on your TC115, with the Tall version coming closer.

 

[fourstr00]

Data point.

Finally had a chance to take the Hathor 1203 to a club date with a rock band. FOH support, but using it as a monitor with drums, keys, violin, sax, guitar, and three singers.

I’ve never been able to hear myself so clearly. Pulled the ports, both switches down, and got big open bass with no strain and no mud. Loading off the stage was a single trip and my entire rig fit underneath a chair.

Just an unreal cabinet. Thanks Duke.

 

[shwashwa]

Hey everybody! I recently picked up a used V1 TC112 and I really love the sound. My main band uses IEM's but I like to have an amp on stage so everyone can feel it a little bit. I have gotten quite a few compliments on the stage sound since I started using the TC!

So, I got back from this weekends travels and I noticed the cab had developed a rattling or buzzing sound (for lack of a better term). The sound gets worse as the volume is increased and it seems to center around a particular note (B flat on the E string), but it will occur on any note with enough volume. It's been a while since I blew a speaker so it could be that, but I run it at such low volumes, it would be hard to imagine. I did a search and all I came up with was loose screws, so I went through and tightened all the screws I could access. Unfortunately, this did not help. I also tried different amps, basses, cabs, cables, rooms, power situations, eq, etc...

Does anyone have any ideas of what this could be? It has sort of a blown speaker sound, but it is volume and (somewhat) frequency dependent. I really didn't want to bother the Duke because it was bought second hand. Thanks for any advice!

just wondering if you ever sorted this out as i seem to be having the same issue centered around the note D. its also a V1 TC112.

 

[MarkA]

just wondering if you ever sorted this out as i seem to be having the same issue centered around the note D. its also a V1 TC112.

I followed a bit from the post you quoted and saw these. Perhaps one or more will help yield some insight. The one time I can for sure recall dealing with an air-leak (not on one of Duke's cabs), I thought the midrange driver or tweeter in the cab was damaged -- I'd get a buzzy, farty sound at relatively low volume on certain notes. Not saying that's what's going on with yours, but might be a possibility. Good luck!

Could be a blown woofer, but here are a few other possibilities:

Might be wires rattling against one another, against the inside flare of the port, or against the crossover board. Wrap wires in duct tape wherever they look suspicious. My wire-securing technique sucked way back then, improved as I went along, and I now try to err on the side of too much tape securing the wires.

Are the ports secured with 4 screws each, or 8 screws each? Some of my early cabs only had 4 screws per port, but after one cab came back a noise issue I started drilling 4 more holes in the flange to make sure there was no air passage underneath the flange.

If you have to remove the ports for some reason, if they have 8 screws, mark the top of each port with bits of tape. This is because there's a fair amount of variation in my four hand-drilled screw holes, so this makes returning to the proper orientation for each port much easier.

When removing the woofer mounting screws, use strong downward pressure ONLY for starting the process. Once the screw turns easily, use ONLY ENOUGH downward pressure to keep the tip securely engaged. What you want to avoid is, pushing out the "hurricane nuts" (variation in the T-nut theme) that the screws go into. Same thing for the screws holding the grille tabs in place. When replacing the screws, same principles apply - only ramp up the downward pressure at the very end. Always use a manual screwdriver instead of an electric so that you can stop immediately if something binds, and back out. You don't want to either spin or push out the hurricane nuts. It's not the end of the world if you do, but it is a hassle.

Feel free to call or e-mail me with any questions, 504-251-2311 and audiokinesis at yahoo dot com.

Air leak

I've been in email contact with Duke and he is getting my issue all sorted out. I just want to take a moment and say the level of service he is giving me is extremely high. I bought a used cabinet and he is going well beyond the call of duty to get this sorted out. This is how you earn a customer for life. I will be buying a new AK cab or two in the near future!

I had the same issue and it turned out to be a fried motor.
Duke sent me a new driver the next day. I also bought the cab used. Folks it doesn't get any better when it comes to service after the sale. Way after the sale.

 

[DukeLeJeune]

just wondering if you ever sorted this out as i seem to be having the same issue centered around the note D. its also a V1 TC112.

My guess is that it's either loose wires, or the woofer itself. I replied to your message with woofer removal instructions, anyway we'll get it sorted out.

 

[LeonD]

My TC115 developed a rattle. It ended up being the tilt back handle/stand on the bottom of the cab.

No rattle when using it; rattle when not using it.

So I use the handle/stand. Beautiful cab. Beautiful sound.

 

[Ken Lloyd]

View attachment 2983171
Just an unreal cabinet. Thanks Duke.

My turn for a gig rig pic. From last night's gig.
My main gig rig now is shown: Lakland 55-02 (8ish pounds); Mesa D800; AK Changeling 112 (one port plugged; grind switch on; treble switch off; rear firing speaker switch off for this gig).

For high powered, fabulous sounding, lightweight and portable rig, this must be right up there with the best there is.

The Mesa head is new to me (got used here on TB); maybe six gigs and a couple rehearsals in big rooms. The Acoustic Image heads I've raved about for many years are still as perfect as ever for what they do, that uncolored response across the 20 to 20KHz frequency range. Powerful, durable, lightweight, reliable, versatile for keys or vocal or anything.

The Mesa D800 surprised me in that it upgraded my sound from what I thought was pretty darn good to even better. Punchier. Sounds bigger. Great tone across the multiple genres we play. I'm digging every tune and every variation of the tone controls (on the bass), and I'm one of those who varies tone often.

Consider: good lead singer; friendly; attractive; gets lots of attention on breaks and after last song. Still, after greeting her and offering their kind words, some of the well-wishers make it a point to find me and say things like, "what a great sound", "you've got great tone" and so on.

It's a great time to be a bass player. So many great options to sound like a pro at reasonable cost.
Looking ahead, I plan to add a Hathor 1203T.

 

[Lowendtech]

Seems rather familiar to some extent.
At the great Caledonia Chili Cookoff yesterday.

 

[nutdog]

We need pics of friendly, attractive singer and chili.

 

[Ken Lloyd]

Seems rather familiar to some extent.
At the great Caledonia Chili Cookoff yesterday.
View attachment 2993043

What's the riser under your cab? Useful?

 

[Lowendtech]

What's the riser under your cab? Useful?

Link Removed
I never go anywhere without it. Extremely useful.

 

[DukeLeJeune]

Last week there was a thread with this title:

"any chance of cabs getting smaller and powerful like guitar cabs in recent years?"

So I hope you guys don't mind me posting my thoughts on the subject here. My response uses one of my cabs as an example to illustrate my points, and imo that be out of place in the other thread.

Here is the primary tradeoff involved: In order to keep the same low-end extension while shrinking the box size, we must trade off efficiency. So we need higher power handling (and a more powerful amp) to get back to the same max SPL. If we want to cut the box volume in half, we would expect to give up 3 dB in efficiency, and in return we would want TWICE the power handling (and obviously we'd need twice the amplifier power to take advantage of that higher power handling).

Woofers which can do that are available today. The 12" Faital 12HP1060 woofer can handle 1000 watts, and it would theoretically work pretty well in a cab HALF the size of the little Hathor 1203!! So, what's stopping me??

Well, here are some of the considerations that, in this case, separate "theoretical" from "practical":

1. The port dimensions needed to tune to the mid-50's and not chuff at high power, especially given the small box size, would be quite difficult to shoehorn into a small box. Chuffing considerations set a lower limit on the port cross-sectional area, and then the smaller the internal volume, the LONGER the port must be, for a given tuning frequency. At the opposite end of the spectrum, you may have seen big vented cabs of yesteryear wherein the port was simply a rectangular hole in the cabinet? In such cases, the internal volume was large enough that a 3/4" long port was long enough to hit the target tuning frequency.

2. The moving mass of the woofer cone, combined with the motor strength, would almost certainly make the cabinet vibrate severely. The cone weighs almost twice as much as the cone of the Kappalite 3012LF, and the motor is a little over twice as strong. By way of comparison, the Hathor 1203 is right at the edge of having a cabinet-vibrating issue: If that cab was a little bit shallower, it would probably happen because the "base" front-to-back would not be great enough to prevent the cab from rocking rapidly back-and-forth. I prototyped a shallower cab with the same 12" Kappalite woofer and it had vibration/rocking issues.

3. The 12HP1060 has weak midrange north of about 400 Hz, so that implies we'd need a very beefy midrange driver to go down that low, given that we want the cab to handle a kilowatt. Finding a place to put that midrange driver makes the box either taller or wider than needed to meet our internal volume target. If we then make the box very shallow in keeping with our "half the size of the Hathor 1203" target, it won't just vibrate, it will bark at you and chase you off the stage and out the door.

4. The 12HP1060 weighs almost twice as much as the Kappalite 3012LF, plus the weight of the beefy midrange section, and so our theoretical ultra-compact kilowatt 112 cab would probably weigh several pounds more than the Hathor 1203. But as we saw from the last couple of points, it's probably not going to be any smaller than the 1203 anyway given the midrange driver requirement and the need to make the cab deep enough that rocking is not an issue. So it could easily end up weighing ten or twelve pounds more. And in this particular case, with the Faital 12HP1060, we start to get a mild dip in the upper bass region as the box size approaches that of the 1203. Not good!

5. In this example, taking the beefy mid into account, the parts cost would be more than three times as much as for the Hathor 1203.

6. [This point turns out to be based on false assumptions on my part, but I'm leaving it in here so you guys can see that I'm still learning too! See Passinwind's post below.] I'm not an amplifier designer, but at some point real-world amplifier power is going to bump up against the limitations of how much wattage can be pulled from a 120-volt, 15-amp (1800 watt) outlet and converted into amplifier output. So while my example above doesn't bump up against that limitation, if my example had been one of my 212 cabs, we'd have to use a 240-volt outlet to get sufficient amplifier power for our theoretical "half-the-size, twice-the-power" cab. [EDIT: Or, not! See Passinwind's post below - he IS an amplifier designer!!]

So... while it's THEORETICALLY possible to trade off 3 dB of efficiency and replace it with twice the power handling and thereby halve the box size, in practice, imo that's not yet practical. The day may come, but imo it's not here yet.

 

[Al Kraft]

Last week there was a thread with this title:

"any chance of cabs getting smaller and powerful like guitar cabs in recent years?"

So I hope you guys don't mind me posting my thoughts on the subject here. My response uses one of my cabs as an example to illustrate my points, and imo that be out of place in the other thread.

Here is the primary tradeoff involved: In order to keep the same low-end extension while shrinking the box size, we must trade off efficiency. So we need higher power handling (and a more powerful amp) to get back to the same max SPL. If we want to cut the box volume in half, we would expect to give up 3 dB in efficiency, and in return we would want TWICE the power handling (and obviously we'd need twice the amplifier power to take advantage of that higher power handling).

Woofers that can do that are available today. The 12" Faital 12HP1060 woofer can handle 1000 watts, and it would theoretically work pretty well in a cab HALF the size of the little Hathor 1203!! So, what's stopping me??

Well, here are some of the considerations that, in this case, separate "theoretical" from "practical":

1. The port dimensions needed to tune to the mid-50's and not chuff out at high power, especially given the small box size, would be quite difficult to shoehorn into a small box.

2. The moving mass of the woofer cone, combined with the motor strength, would almost certainly make the cabinet vibrate severely. The cone weighs almost twice as much as the cone of the Kappalite 3012LF, and the motor is a little over twice as strong. By way of comparison, the Hathor 1203 is right at the edge of having a cabinet-vibrating issue: If that cab was a little bit shallower, it would probably happen because the "base" front-to-back would not be great enough to prevent the cab from rocking rapidly back-and-forth. I prototyped a shallower cab with the same 12" Kappalite woofer and it had vibration/rocking issues.

3. The 12HP1060 has weak midrange north of about 400 Hz, so that implies we'd need a very beefy midrange driver to go down that low, given that we want the cab to handle a kilowatt. Finding a place to put that midrange driver makes the box either taller wider than needed to meet out internal volume target. If we then make the box very shallow in keeping with our "half the size of the Hathor 1203" target, it won't just vibrate, it will bark at you and chase you off the stage and out the door.

4. The 12HP1060 weighs almost twice as much as the Kappalite 3012LF, plus the weight of the beefy midrange section, and so our theoretical ultra-compact kilowatt 112 cab would probably weigh several pounds more than the Hathor 1203. But as we saw from the last couple of points, it's probably not going to be any smaller than the 1203 anyway given the midrange driver requirement and the need to make the cab deep enough that rocking is not an issue. And in this particular case, with the Faital 12HP1060, we start to get a mild dip in the upper bass region as the box size approaches that of the 1203. Not good!

5. In this example, taking the beefy mid into account, the parts cost would be more than three times as much as for the Hathor 1203.

6. I'm not an amplifier designer, but at some point real-world amplifier power is going to bump up against the limitations of how much wattage can be pulled from a 120-volt, 15-amp (1800 watt) outlet and converted into amplifier output. So while my example above doesn't bump up against that limitation, if my example had been one of my 212 cabs, we'd have to use a 240-volt outlet to get sufficient amplifier power for our theoreticaol "half-the-size, twice-the-power" cab.

So... while it's THEORETICALLY possible to trade off 3 dB of efficiency and replace it with twice the power handling and thereby halve the box size, in practice, imo that's not yet practical. The day may come, but imo it's not here yet.

Nice discussion of how one defines and navigates conceptual design trade-space Duke!

 

[DukeLeJeune]

Nice discussion of how one defines and navigates conceptual design trade-space Duke!

Thank you Al!

Not obvious from my post above is the fact that I DO like Faital's 4" voice coil motor used in their "HP1060" series. Imo the 18" version is the most promising. In a big cab like the 18HP1060 calls for, a beefy midrange driver doesn't drive the cab into the "impractical" end of the spectrum.

 

[Passinwind]

6. I'm not an amplifier designer, but at some point real-world amplifier power is going to bump up against the limitations of how much wattage can be pulled from a 120-volt, 15-amp (1800 watt) outlet and converted into amplifier output.

Assuming a 33% duty cycle for bass guitar playing demanding program material (which typically implies substantial distortion and/or compression), something in the rough ballpark of 4000 watts with a decently efficient Class D amp.

 

[Type-55]

Duke,
You should write a book and charge for your knowledge.
Seriously.

 

[DukeLeJeune]

Duke,
You should write a book and charge for your knowledge.
Seriously.

I DO charge for my knowledge. Have you seen the prices on my cabs??

Seriously, this stuff is my hobby as well as my business. At the end of a long day of dodging tablesaw blades and inhaling solder fumes, I like to unwind by designing imaginary speakers. Occasionally I stumble across something that seems promising, but mostly it's just entertainment.

 

[DukeLeJeune]

Assuming a 33% duty cycle for bass guitar playing demanding program material (which typically implies substantial distortion and/or compression), something in the rough ballpark of 4000 watts with a decently efficient Class D amp.

Wow! Okay, I'm editing my post!