AudioKinesis 112 Cab

[John D Harris]

Actually the key is often to tune LOWER if one wants to achieve what some define as "tight". I've talked about it in my threads, and a little bit here too: http://www.talkbass.com/wiki/index.php/Shelf_extension . Some real time and understanding in a cab sim program will illustrate what goes on... Once you get to a certain threshold in size for any particular driver it's difficult not to have a boomy midbass, but I believe Duke is well south of that, as am I with the fEarfuls in stock tuning, and even more so when you lengthen the porting (which I personally do).

With commercial cabs of too small size for the driver, it becomes apparent, because even when you roll off the lowest bass EQ they will tend to boominess still, and if you do not, are more prone to driver farting because of tuning too high relative to the incoming content's energy distribution.

But with the right driver, enclosure size, and tuning it is possible to have good bass extension and yet a perception of deeper bass. Of course in bass player circles it is very hard to discuss this stuff since many are still convinced they are hearing primarily fundamentals when in fact they are hearing an octave or more above the fundamental and calling that "deep".

Thanks for clearing up my confusion.
Seems counter-intuitive to me, but I know zilch about this area of science.

 

[rpsands]

Thanks for clearing up my confusion.
Seems counter-intuitive to me, but I know zilch about this area of science.

Port tuning basically gives you a bump just above the frequency you tune to followed by something like a 24db/octave rolloff under the frequency. The awesome part is this bump can counteract the early rolloff you'll see if you look at free air driver charts...most of them start rolling off above 100hz.

But, add a big boost above 45hz and a fast rolloff after that, you sacrifice nothing and gain a bunch of volume from 45 to 100hz.

The down side is that if you tune a box too low you don't get in the sweet spot which makes it superior to port vs. seal the enclosure. Add a big bump at 30hz to a driver that's down 20db at 30hz and you're not adding anything of value.

The other downside is under your tuning frequency you have a phenomenon where the driver will "unload" -- that is, excursion increases dramatically.

So while tuning your cab to 70hz might look good in Winisd, you have to look at the excursion chart, and you'll see that your driver's now working crazy hard under 70hz...so play an open B and watch the driver light up like a roman candle (figuratively speaking)

There're other big problems with tuning too high too, like insane boom potentials.

Anyway, that's not really a very good sciency explanation but I hope it helps give a little bit more info if you're interested.

 

[John D Harris]

Port tuning basically gives you a bump just above the frequency you tune to followed by something like a 24db/octave rolloff under the frequency. The awesome part is this bump can counteract the early rolloff you'll see if you look at free air driver charts...most of them start rolling off above 100hz.

But, add a big boost above 45hz and a fast rolloff after that, you sacrifice nothing and gain a bunch of volume from 45 to 100hz.

The down side is that if you tune a box too low you don't get in the sweet spot which makes it superior to port vs. seal the enclosure. Add a big bump at 30hz to a driver that's down 20db at 30hz and you're not adding anything of value.

The other downside is under your tuning frequency you have a phenomenon where the driver will "unload" -- that is, excursion increases dramatically.

So while tuning your cab to 70hz might look good in Winisd, you have to look at the excursion chart, and you'll see that your driver's now working crazy hard under 70hz...so play an open B and watch the driver light up like a roman candle (figuratively speaking)

There're other big problems with tuning too high too, like insane boom potentials.

Anyway, that's not really a very good sciency explanation but I hope it helps give a little bit more info if you're interested.

Thanks!

 

[greenboy]

The best expanation to all this stuff is to spend a lot of hours operating cab sim programs and building speakers and re-tuning them. It clears up so many misconceptions, and pokes holes in the majority of marketing materials found in the bass cab sector.

 

[John D Harris]

The cabinet tuning I'd really like to do would be a vented box tuned so that its response approximates a good sealed box, but goes considerably deeper. The Thunderchild is fairly far removed from that ideal, but the characteristics of the stock 3012LF woofer will allow the 212 will come a bit closer.

That sounds interesting!

 

[greenboy]

That sounds interesting!

I've gone down that lane. That's what happens when you plug one side of the shelf port on the 15/6 or 15/6tube. But I've found it a lot easier with non-tube heads jsut to roll off the bass if one's EQ facilities are relatively decent, and in most gigging situations a closed box response sounds pretty gutted.

In smaller rooms though, it's still worth considering. If anyone can do it well, it'll be Duke.

 

[John D Harris]

Actually the key is often to tune LOWER if one wants to achieve what some define as "tight". I've talked about it in my threads, and a little bit here too: http://www.talkbass.com/wiki/index.php/Shelf_extension . Some real time and understanding in a cab sim program will illustrate what goes on... Once you get to a certain threshold in size for any particular driver it's difficult not to have a boomy midbass, but I believe Duke is well south of that, as am I with the fEarfuls in stock tuning, and even more so when you lengthen the porting (which I personally do).

...

It would be interesting to experiment with your adjustable port-shelf and see what kind of low-end tuning works best for you!

 

[Jazzdogg]

This cab is intriguing, and the port plugs are a great idea.

When two of these cabs are stacked, does coupling effect perceived frequency response?

I keep wondering if the port plugs could be placed beneath the front edge of the cabinet baffle as a tilt-back device when the'ye not being used to "seal" the cabinet.

 

[DJ Bebop]

 

[lookiel]

Bepop you seem to have an EA CXL-112 in that pic,
I used to own one and would be curious to know how they compare!
I imagine the Thunderchild has a lot more bottom end and is more balanced?

 

[KJung]

This cab is intriguing, and the port plugs are a great idea.

When two of these cabs are stacked, does coupling effect perceived frequency response?

I keep wondering if the port plugs could be placed beneath the front edge of the cabinet baffle as a tilt-back device when the'ye not being used to "seal" the cabinet.

Stacking two of these would be the same as stacking any two identical cabs. Again, this cab was really designed as a stand-alone solution, but I guess if you have a head that can safely do 2ohms, or a 'dual mono' head like the Shuttle Max 12, that would be an option.

I guess to maintain the beautiful midrange dispersion, you would stack the top cab 'upside down' if you went with two.

The beauty of this cab IMO is that you get 'almost 212 performance in a small box with a moderately powered head. If you need more wump than that, I'd just do with a bigger box. IMO there!

 

[IntrepidCellist]

Stacking two of these would be the same as stacking any two identical cabs. Again, this cab was really designed as a stand-alone solution, but I guess if you have a head that can safely do 2ohms, or a 'dual mono' head like the Shuttle Max 12, that would be an option.

I guess to maintain the beautiful midrange dispersion, you would stack the top cab 'upside down' if you went with two.

The beauty of this cab IMO is that you get 'almost 212 performance in a small box with a moderately powered head. If you need more wump than that, I'd just do with a bigger box. IMO there!

Duke says you can stack them at 90 degrees to each other for near 180-degree dispersion.

 

[KJung]

Duke says you can stack them at 90 degrees to each other for near 180-degree dispersion.

I would assume that would also be true of any stack of two identical cabs (i.e. increased midrange dispersion if you pointed them away from each other).

 

[kringle77]

Would that mean stacked vertical with the top cab turned at a 90 degree angle or place on the ground next to eachother facing apart at 90? I guess that it could be done either way.

 

[KJung]

Would that mean stacked vertical with the top cab turned at a 90 degree angle or place on the ground next to eachother facing apart at 90? I guess that it could be done either way.

I would guess at that extreme angle, it shouldn't matter, and with them stacked with the top one upside down, or both on the floor, the horns would still be in that 'same vertical plain' that the EE guys talk about.

 

[babebambi]

Can a Shuttle / Shuttle Max 6 drives this cab to its full potential?

 

[KJung]

Can a Shuttle / Shuttle Max 6 drives this cab to its full potential?

IMO, yes. It is 4ohm, and has both the mechanical and thermal specs to easily handle (and quite frankly, need) 400-600 or so watts. I'm driving mine with a Markbass F500 or LMII, and it takes it all, but handles it all too!

 

[babebambi]

THX Ken.
But my question is actually backward...
I mean whether the GB has enough juice ...

IMO, yes. It is 4ohm, and has both the mechanical and thermal specs to easily handle (and quite frankly, need) 400-600 or so watts. I'm driving mine with a Markbass F500 or LMII, and it takes it all, but handles it all too!

 

[KJung]

THX Ken.
But my question is actually backward...
I mean whether the GB has enough juice ...

I guess I kind of answered backwards, but the gist is the same... yes even though Genz uses that different, more 'forgiving' type of power spec, the 600 rated watts of the Shuttle 6 or Max 6 should be plenty to drive the Thunder Child. The Max 6 would be much better IMO than the 6, given its fuller low end voicing and MUCH better EQ, although it might be a bit large to sit on top of that amp. If you were sold on the Genz stuff, the Shuttle 9 would probably be the best choice, and the 9 doesn't seem to put out massively more wump than most of the other micro's (like the GK or F500, etc.).

IMO though... have not had the chance to try a Genz head with this cab. Should sound nice though.

 

[JxBass]

I guess I kind of answered backwards, but the gist is the same... yes even though Genz uses that different, more 'forgiving' type of power spec, the 600 rated watts of the Shuttle 6 or Max 6 should be plenty to drive the Thunder Child. The Max 6 would be much better IMO than the 6, given its fuller low end voicing and MUCH better EQ, although it might be a bit large to sit on top of that amp. If you were sold on the Genz stuff, the Shuttle 9 would probably be the best choice, and the 9 doesn't seem to put out massively more wump than most of the other micro's (like the GK or F500, etc.).

IMO though... have not had the chance to try a Genz head with this cab. Should sound nice though.

I'll be wringing out the Shuttle 9 with my Thunderchild soon, hopefully in the next 10-12 days. I'm very interested in comparing it to my LMII, which Ken said goes very well with this terrific cab. So far the S9 has relegated my beloved LMII to backup status; we'll see if that continues