[Passinwind]

Duke, how about a little rundown on all the new pieces you showed up in Seattle last weekend? Hearing violin through a couple of your cabs was especially cool, and of course I always really enjoy getting to try out my DIY electronics through your stuff as well.

Edit: since this thread is already getting quite a few views, here are a couple of the new cabs:

Thunderchild 118



Hathor 1203

[Duke]

Wow, thank you, Charlie! 

I've been meaning to do a thread like this, always seemed like something else needed to be done first, so thank you for getting it started. 

I have two series of bass cabs:  The Thunderchild series, and the Hathor series.  The Thunderchild cabs are of the more hi-fi variety, some have said "studio-monitor like", and are more readily adaptable to a wide range of musical instruments (just about everything other than electric guitar, which usually calls for speakers with particular characteristics that are not compatible with reproducing bass energy at high volume). 

Most of my cabs are designed with the first overtone of low-B, 62 Hz, very much in mind.  Being able to deliver the first overtone of low-B at approximately full power (down no more than 4 dB) is, in my mind, sort of a required threshold for a high-end bass cab. 

The original Thunderchild series is now in its Version 2 incarnation, wherein the original rectangular horn has been replaced with a square "baby butt cheeks" style horn (and crossover tweaked accordingly).  This gives better dispersion in the vertical plane for situations where you're very close to the cab on a tight stage. 

Let's take a look at the current Thunderchild series:

Thunderchild 112, available in 4 or 8 ohms.  Dimensions 22" tall by 14" wide by 14" deep; 30 pounds; 95 dB in 4 ohms and 94 dB in 8 ohms; -3 dB in the upper 50's in 4 ohms, and -3 dB in the lower 50's in 8 ohms, 500 watts.  The Thunderchild 112 in 4 ohms was my first bass cab, and is what put me on the map (well, on some maps anyway).  $800 + shipping.  The one on the left is a 4-ohm cab, and the one on the right is an 8-ohm cab (I can tell by the color of the bugscreen on the compression drivers):


*  *  *  *
Thunderchild 115, now in its third version, is switchable between 4 and 8 ohms, and uses the custom Kappalte-based woofer developed for the Hathor 1505 (see below).  As a result, this is the first Thunderchild cab that has a usable "growly" mode.  Dimensions 25" tall by 17" wide by 15" deep; 38 pounds; 98 dB; -3.5 at 62 Hz (the first overtone of low-B); 500 watts.  This cab and the Thunderchild 112 are being used for home audio by some of my customers, among other roles that are unorthodox for a bass cab.  $1000 + shipping:


*  *  *  *
Thunderchild 212, 4 ohms.  Dimensions 34.5" tall by 14.5" wide by 14.5" deep; 47 pounds; 97 dB; -3 dB in the mid-50's; 900 watts.  This cab offers a lot of sound in a fairly compact footprint, and some have said that it's my best bass cab.  It's also currently tied for most expensive, at $1200 + shipping:


*  *  *  *
Thunderchild 118, 8 ohms.   Dimensions 30" tall by 20" wide by 15" deep; 43 pounds; 97 dB: -3 dB in the upper 40's; 600 watts.  This is a relatively new cab, which distinguished itself in Seattle a little over a week ago by winning over a bass player and his wife, who plays electric violin.  Not bad for a two-way with an 18" woofer!  Introductory price is $1000 + shipping, so it's serious competition for the Thunderchild 115:


*  *  *  *
Any of the Thunderchild cabs can be fitted with the rear-firing "acoustic friendly" tweeter for another hundred bucks.  This tweeter is covering the same part of the spectrum as the front-firing horn, but at a lower SPL.  This is mainly useful if you're going to be amplifying acoustic instruments like upright bass or cello or violin, or if you're going to be standing behind the cab for some reason (it helps you hear the overtones), or for your drummer (so that he has a better chance of being able to tell what note you're playing).   Here's a shot of one of these rear-firing tweeters, on the right:


This is the backside of the two Thunderchilds 112 you saw above.  The 8-ohm one has the rear-firing tweeter.  It also has two switches instead of just one; both cabs have a top-end rolloff switch that rolls off the top end of the compression driver north of 3.5 kHz or so (all of my Thunderchild cabs have this switch), but the 8-ohm cab has a second switch that toggles between smooth and just a little growly in the upper mids.   The TC115 and 212 also have this midrange smoothy/growly switch, but the 118 does not. 

And last but not least you see both ports plugged in the 8 ohm cab.  Let me tell you a bit about method and the madnesss to my porting:

I use flared ports by Precision Ports, and the flares help to delay the onset of chuffing relative to other port shapes.  The ports are positioned right smack behind the woofer cone, so that midrange energy escapes through the ports.  Imo this is desirable with the flares, as a second benefit of the flares is low coloration of the midrange energy that comes through them.   In the acoustic friendly versions, this output combines with the tweeter's output to give you essentially fullrange energy behind the cab, albeit at reduced level compared with what's happening out in front of the cab.

The ports are positioned symmetrically behind the woofer cone, so that the cone doesn't see an asymmetrical airload.  With long-voice-coil woofers in small boxes, an asymmetrical airload can result in enough cone-rock to cause the voice coil to click against the sides of the magnetic gap, which is a distraction we can do without. 

Notice that one port is higher than the woofer magnet, and one port lower.  This facilitates a bit of chimney-effect cooling, as hot air exits the top port, drawing cool air into the bottom port.  The idea is to delay the heating of the magnet, as hot magnets lose strength (temporarily), and you don't want the cab to come up short on SPL for the last song of the set.  The reason the ports are on a diagonal is packaging; not enough room to align them vertically - the inside of that cab is pretty busy.

My 115 and 118 cabs have four ports in a square behind the cone, and my 212 has three ports in a vertical line.  In any of my Thunderchild cabs you can plug some or all of the ports and tighten up the low end accordingly, which can be useful for that once-a-year gig in that superboomy room.  Or if you want to crank in some aggressive low-end EQ, the ability to choose different tuning frequencies can come in handy.  I recommend port-plugging geometries that maintain a symmetrical airload as much as possible, so if we're going to plug two of the four ports on a 115 or 118, do it on a diagonal.

My wattage claims are both thermal and mechanical, and I use high-quality long-excursion woofers from Eminence and Faital, but my cabs can theoretically still be farted out by excessive low-end boost.  My efficiency claims are calculated from the woofer's T/S parameters, and my -3 dB claims are based on modeling software.  My weight claims are rounded up to the nearest pound.  My dimension claims make allowance for the pooch-outness of the grilles. 

I work just as hard on the crossovers of the Thunderchild cabs as on my home audio speakers, but I do give higher priority to power handling and total parts cost because those are more important considerations for the musical instrument cab market.

My Thunderchild series cabs are imo legitimately multi-role cabs, or light-duty PA cabs with enough excursion for bass guitar.  But I really haven't tried campaigning them in other markets.   At some point in the not-too-distant future, a pair of TC118s may be moonlighting as keyboard cabs for an electronica project.

[G Georgopoulos]

Hi

after spending many years designing ported and sealded box speakers
one thing is for sure mount a driver to ob speaker,no box acoustics just
plain driver specs

it works perfectly,and is simple!

i dont claim to be a speaker expert by the way...

[Duke]

Hi

after spending many years designing ported and sealded box speakers
one thing is for sure mount a driver to ob speaker,no box acoustics just
plain driver specs

it works perfectly,and is simple!

i dont claim to be a speaker expert by the way...

That's a perfectly valid suggestion, and I looked into open baffle bass cabs at one point, but it didn't seem practical.

Aside from open-back guitar cabs (most of which are actually high-tuned ported cabs), I don't recall seeing many open-baffle prosound cabs.

One of the problems with open baffle is achieving high SPL at low frequencies, and another is delivering chest-whumping impact.  Doing that in a relatively compact, portable open baffle cab is a long shot.  Doing it at a competitive price and weight is an even longer shot because of all the woofers you'd need for adequate displacement.  My thousand-dollar. 43 pound 118 can do 125 dB at 60 Hz without exceeding its thermal or mechanical limits, no EQ needed.   How many woofers (of your choice) and how big a baffle would you need to match that?   What would such a cab cost and weigh? 

Placing the ports right behind the woofer cones, like I do, gives my cabs a little bit more of the openness in the midrange that characterizes a good open baffle speaker.  In my next post I'll talk about my Hathor series of cabs, which comes even closer to behaving like an open baffle in the midrange. 

[G Georgopoulos]

Aside from open-back guitar cabs (most of which are actually high-tuned ported cabs), I don't recall seeing many open-baffle prosound cabs.

One of the problems with open baffle is achieving high SPL at low frequencies, and another is delivering chest-whumping impact.  Doing that in a relatively compact, portable open baffle cab is a long shot.  Doing it at a competitive price and weight is an even longer shot because of all the woofers you'd need for adequate displacement.  My thousand-dollar. 43 pound 118 can do 125 dB at 60 Hz without exceeding its thermal or mechanical limits, no EQ needed.   How many woofers (of your choice) and how big a baffle would you need to match that?   What would such a cab cost and weigh? 

Placing the ports right behind the woofer cones, like I do, gives my cabs a little bit more of the openness in the midrange that characterizes a good open baffle speaker.  In my next post I'll talk about my Hathor series of cabs, which comes even closer to behaving like an open baffle in the midrange.

Box dynamics have pro's and con's ,if you have ob you bypass those, it's not having too much bass
with ob speakers just as the signal requires,mids and highs are not and insue only bass and if you
want more than a bigger baffle can do that...and it's all simple!!!

[Duke]

All of the Thunderchild cabs use high quality PA-style horns, which are quite good for some things (like accuracy and clarity) but not the best choice for others (like reproducing an intentionally distorted signal).  So we also have the Hathor series, which uses cone midrange drivers and no horns (at least not yet - I may do a three-way with a horn one day).   This series is "voiced" specifically for bass guitar, though it looks like I'll be including "smoother switches" on most models so that people can get a smooth voicing out of them if they want.   

The super-cool feature of the Hathor cabs is an open-format mid-chamber.  The cone midrange drivers are in a chamber that is open on the top and sides, which allows the backwave energy to escape in those directions, giving a more open sound.  And in particular the upfacing openings allow some of the backwave energy to bounce upwards, where you can hear it if you're jammed right up on top of the cab on a tight stage, so you can still hear your overtones. 

The native voicing of the Hathor cabs includes emphasis in the 1-2 kHz octave, followed by some dippage in the 2-4 kHz octave.  The 1-2k emphasis gives us a bit of a growly voicing, and the 2-4k dip keeps us from fighting with the electric guitars in the region where they have a major peak.   

Hathor 1203, 8 ohms.  Dimensions 18" tall by 14" wide by 13.5" deep; 25 pounds; 95 dB; -3 dB at 63 Hz.  This is a lot of cab in a small, fairly lightweight package.   With the smoother switch engaged it's viable, though not ideal, for upright bass.  An obvious selling point is that you can just use one for small gigs, and two for large gigs. so to make that point, my marketing department wanted me to show two stacked.  Notice the openings in the top and sides for the midrange energy to escape.  500 watts (same woofer as the 8-ohm TC112), regular price $650 + shipping.  If you don't want the midrange smoother switch, you can save 1.6 pounds and $50:


*  *  *  *
Hathor 1855, 4 or 8 ohms.  Dimensions 28" tall by 20" wide by 15" deep; 50 pounds; 96 dB; -3 dB @ 46 Hz (first overtone of low F#).  This cab has a powerful subwoofer with 3 dB more air-moving capability than the TC118, and it survived an encounter in Seattle with what I think would be called a "sub-contra bass" whose lowest open string was about 13 Hz (G#00)!  No my cab didn't reproduce the fundamental, and didn't really even reproduce the third harmonic, but according to the luthier who built the bass, it aquitted itself better than any other cab he's tried.  $1200 + shipping.

The twin 5" mids give a very nice, open presentation, especially in their open-format mid chamber.  The bottom end is quite authoritative.   There are two switches on the back, one to smooth out the upper-mid emphasis, and the other to take down the top end a bit (it kind of stands out once you smooth the mids).   



*  *  *  *

Hathor 1505, switchable between 4 and 8 ohms, 25" tall by 18" wide by 14" deep; 98 dB; 38 pounds; -4 dB at 62 Hz.  The Hathor 1505 uses a custom 15" woofer based on the Eminence Kappalite motor, and a new 5" midrange by Eminence.   Imo the bottom end sounds bigger than some of my bass cabs that go lower on paper, not sure why.  The custom woofer has a bit of built-in growly, which can be smoothed via a switch on the back.  Another switch toggles between "4 ohm" and "8 ohm" modes, but the difference isn't a great as those numbers suggest - the cab starts out as a "high 4 ohms" cab, and the switch adds just enough series resistance for the cab to qualify as an "8 ohm" cab so that it can safely be connected in parallel with another 8 ohm cab and driven by a 4-ohm rated amp.  500 watts.  $900 + shipping. 



The width matches the height of the Hathor 1203, making them easy to stack for a loud gig:

[Duke]

Box dynamics have pro's and con's ,if you have ob you bypass those, it's not having too much bass
with ob speakers just as the signal requires,mids and highs are not and insue only bass and if you
want more than a bigger baffle can do that...and it's all simple!!!

I will agree with you on one point: Open baffle cabs are simple.

I know of one manufacturer who set out to develop an open-baffle bass cab specifically for upright bass, taking advantage of the dipole null to the side to minimize feedback.  Upright bass isn't nearly as demanding in terms of SPL as electric bass, so this seems like the ideal application for an open-baffle bass cab.  Well that was several years ago and apparently he has abandoned the project.  Presumably it proved impractical for some reason, as taking advantage of that null is very creative and would have been a strong selling point. 

[G Georgopoulos]

I will agree with you on one point: Open baffle cabs are simple.

I know of one manufacturer who set out to develop an open-baffle bass cab specifically for upright bass, taking advantage of the dipole null to the side to minimize feedback.  Upright bass isn't nearly as demanding in terms of SPL as electric bass, so this seems like the ideal application for an open-baffle bass cab.  Well that was several years ago and apparently he has abandoned the project.

Hi Duke!

after many years of diy speakers i have come to two conlusions either ob speaker are
good and sealed speakers are good,now tell me what is your best

cheers...

[Duke]

Hi Duke!

after many years of diy speakers i have come to two conlusions either ob speaker are
good and sealed speakers are good,now tell me what is your best

cheers...

The short answer is, it depends on the application; that is, what the goals and limitations are.

I'd rather not go into the long answer here, as this thread is about my musical instrument cabs, all of which use bass-reflex enclosures that offer the user a choice of tuning frequencies and/or the option of plugging all the ports and converting the enclosure into a low-Q sealed box. 

[Passinwind]

Wow, thank you, Charlie! 

I've been meaning to do a thread like this, always seemed like something else needed to be done first, so thank you for getting it started. 

Heh, just got you to do most of the needed updates for your website...

I'll just mention that I personally played through five of the new designs in Seattle and was deeply impressed by every one of them. I am a multi-purpose user, so for me the TC118 has extra appeal on the strength of its extreme versatility. That waveguide/compression driver combination is just exceptional in my book.

[coolhandjjl]

Been looking at some lighter gear, I am a rock and roll electric bass player. Just can't lug and haul the old iron amps and huge cabs anymore. Looking at the Demeter VTBPM800D amp for starters. Lots of cool AudioKinesis cabs presented here. I see the TC212 may be a contender. For the ease and weight of carrying two 1 woofer cabs and stacking them, I see the TC112. What's the difference between the Hathor 1203 and the TC112 aside from price?

[Passinwind]

Hey Duke,

Sounds like the hi-fi side is blowing up in a really good way for you these days, but it's been a while since we've seen any updates here on the MI cab side. Care to expound a bit?

I recently purpose-built a new bass amp with a form factor meant to sit on my Thunderchild 112AF cab without the much dreaded T/overhang syndrome that a full rack width brings. It makes around 650 watts @ 4 ohms and is my favorite so far with this cab.

[James Romeyn]

Hey Duke,

Sounds like the hi-fi side is blowing up in a really good way for you these days, but it's been a while since we've seen any updates here on the MI cab side. Care to expound a bit?

I recently purpose-built a new bass amp with a form factor meant to sit on my Thunderchild 112AF cab without the much dreaded T/overhang syndrome that a full rack width brings. It makes around 650 watts @ 4 ohms and is my favorite so far with this cab.

Very nice amp! 

Have you auditioned a Hypex NCore amp driving Duke's TC?  I sell Duke's speakers, own many, and my friend/bass player owns a TC.  NCore and TC were separated at birth IMO.  Power DIY NC400 400/600W @ 4/2 Ohm, 1 Ohm minimum....NC400 BTL bridged 800/1200W @ 4/2 Ohm, 1 Ohm minimum.  NC500 is unfortunately not DIY, OEM only: 550W/600W @ 4/2 Ohm, 1 Ohm minimum.  (All 1/3rd duty cycle, not RMS.)  I suspect if you heard NCore > TC you'd not be able to part with it.

In the bass range, especially in dynamics, NCore takes on all high end comers.     

[Passinwind]

Have you auditioned a Hypex NCore amp driving Duke's TC?  I sell Duke's speakers, own many, and my friend/bass player owns a TC.  NCore and TC were separated at birth IMO.  Power DIY NC400 400/600W @ 4/2 Ohm, 1 Ohm minimum....NC400 BTL bridged 800/1200W @ 4/2 Ohm, 1 Ohm minimum.  NC500 is unfortunately not DIY, OEM only: 550W/600W @ 4/2 Ohm, 1 Ohm minimum.  (All 1/3rd duty cycle, not RMS.)  I suspect if you heard NCore > TC you'd not be able to part with it.

In the bass range, especially in dynamics, NCore takes on all high end comers.     

James, Hypex power amp modules have been on my radar for several years, but I only have heard the UcD400 and UcD700 ones thus far. I had been planning on doing a UcD700 based build last year until someone at ICEpower saw my 500ASP based build thread on Talkbass and asked me to try doing an amp with their new 700ASC module, which is also rated for 33% duty cycle rather then the 12.5% ratings on their older modules that were commonly used in many commercial bass amps for the last several years. The built in SMPS with a decent aux power supply for my preamp made that a pretty appealing option while I continued to refine my board layout chops, work on CAD skills for the enclosure design, and so on. I'm still looking at quite a steep learning curve there, but I tend to thrive on that.

 Hypex has historically been a very DIY-friendly company, so naturally I am going to be  inclined to try to do something with the OEM NC500 rather than the DIY'er-centric NC400. I'm fairly well connected, but I've pretty much blown my budget for this year already and still have quite a lot of work left to do on my onboard bass preamp design that I showed in a few booths at NAMM this year.

Thanks for your thoughts, and also for your kind words. And of course I concur that Duke's speakers deserve nothing but the best in peripheral gear.

.........................Charlie Escher

[James Romeyn]

I'm still blown away by how good TC works.  My friend bought the "Acoustic Friendly" version w/rear firing tweeter.  One of it's best qualities is wide dispersion, broader than all or most bass cabinet.  My friend w/the TC owns over a dozen basses including two uprights, one of which is vintage.

I was digging his playing for several minutes in his living room, then I looked down and saw I faced TCs back side.  When I turned TC around so the front faced me it didn't sound that much different.   I'm sure other band members hear the bass more with TC than with lesser cabinets. 

[G Georgopoulos]

The short answer is, it depends on the application; that is, what the goals and limitations are.

I'd rather not go into the long answer here, as this thread is about my musical instrument cabs, all of which use bass-reflex enclosures that offer the user a choice of tuning frequencies and/or the option of plugging all the ports and converting the enclosure into a low-Q sealed box.

plugging port(s) converting to high-q sealed box if it's a reflex box?...