MOAK: The Mother of All Karlsonators (aka The Magnificent Monster)

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Hi guys

I had an idea for a subwoofer. I posted the original idea in the Mini Karlsonator (0.53X) with Dual TC9FD's thread. Here is my original post:

Hi guys

I am sorry to come into this thread sideways, but I would first like to hear if my idea is viable at all before I start a whole thread on it.

I want to build a pair of high quality subs for home use. The drivers I am going to use for this sub are the 13" Leak Sandwich bass drivers. I already have 1 pair of ceramic bass drivers and 1 pair of alnico drivers. I am going to get another pair of each for the sub idea I have in mind. Each box will have two ceramic and two alnico drivers in. I will be quad-amping each sub. One of the main box design ideas for I have in mind is a mega-Karlsonator, and I want to know if it will work.

The boxes that I am planning to build will be 188cm (1.88m/74"/6.16ft) tall x 57cm (22.44") wide x 55cm (21.65") deep. The internal measurements will be 182cm (71.65") x 51cm (21.08") x 49cm (19.29"). With that height it will be a real mega-Karlson to start with, but I want to make it a Karlsonator (Karlson crossed with TQWP) design. I estimate with the height of the box that this design should go down low, very close to 20Hz at the bottom end. The problem is that I don't have any TSPs for any of the drivers, but I will also be buying the Dayton measuring suite, and I will be measuring each individual driver. But before I even start that, I want to know if such an idea will work at all. If the Karlson experts give the green light for this idea, I will create a new thread on the Subwoofer forum. Here is a pic for my idea:

An externally hosted image should be here but it was not working when we last tested it.


Thanks,
Deon

The end result will look something like this, but just much larger:

361253d1374324503-mini-karlsonator-0-53x-dual-tc9fds-completed-pair.jpg


I do not have any TSPs for the Leak Sandwich drivers yet, so I suggested xrk971 (our forum Karlsonator guru) use some Acoustic Elegance drivers to sim the result:

How about doing a sim with either of the following Acoustic Elegance drivers, just as a proof of concept. I would love to see the results.

Acoustic Elegance Lambda Series TD15H-8ohm:
T/S Parameters:
Fs: 21 Hz
Qms: 4.23
Vas: 467 Liters
Cms: 0.45 mm/N
Mms: 129 grams
Rms: 4 Kg/S
Xmax: 14 mm (peak)
Xmech: 20 mm (peak)
Sd: 855 cm2
Qes: 0.27
Re: 6.5 ohms
Le: 0.3 mH
Z: 8 ohms
Bl: 20.1 T/m
Pe(max): 500 Watts
Pe(transient): 1000 Watts
Qts: 0.26
"no": 1.51 %
1W Spl: 94dB
2.8V SPl: 94.84dB

Acoustic Elegance Lambda Series TD12H-8ohm:
T/S Parameters:
Fs: 26.7 Hz
Qms: 3.72
Vas: 160 Liters
Cms: 0.4 mm/N
Mms: 88.6 grams
Rms: 4 Kg/S
Xmax: 14 mm (peak)
Xmech: 18 mm (peak)
Sd: 530 cm2
Qes: 0.25
Re: 6.5 ohms
Le: 0.3 mH
Z: 8 ohms
Bl: 19.7 T/m
Pe(max): 500 Watts
Pe(transient): 1000 Watts
Qts: 0.23
"no": 1.18 %
1W Spl: 92.9dB
2.8V SPl: 93.77dB

Freddi also suggested trying an MCM woofer:

hey X - I've got a cheap pick for this project - it not a huge air pump and qts might be somewhat low - got to test mine

MCM 55-1465 Dual Voice Coil Woofer

this driver was used by Marshall Leach in a sub - sat system.

they're $40.99 each 4 and up

MCM Audio Select 12'' Dual Voice Coil Woofer | 55-1465 (551465) | MCM Audio Select

Poly treated paper cone
Rubber surround
Stamped steel basket
2" voice coil
42.6oz. magnet

Specifications::
Power Capacity: 100W/200W RMS/peak (per coil)
Sensitivity: 93dB (W/M)
Impedance: 8ohm (per coil)
Re: 5.8ohm (per coil)
Le: 0.59mH (per coil)
Frequency response: 25Hz~3KHz
Fs: 25Hz
Qts: 0.30
Qes: 0.32
Qms: 3.13
Vas: 203.81 (liters)
Xmax: 5.0mm


in a cluttered room mounted in Karlson 12 with its vents sealed - mic 20inches from aperture - its really pretty punchy - IIRC, qtc in the little K12 is around 1.05 with no fill. This woofer in a sealed K12 might make a F.A.S.T. system that is compact.

An externally hosted image should be here but it was not working when we last tested it.

xrk971 told me that this is actually more of a tapped horn crossed with a Karlsonator, not a TQWP/Karlsonator cross. xrk971 also said he is a bit tied up at the moment, but he will sim the results as soon as he has a chance. He also suggested posting the results in the Subwoofer Forum, hence me posting all these details here. I am looking forward to seeing what the results will be.

Enjoy,
Deon
 
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there should be some drivers to make this work well in 1-2-3-4 x12"/whatever size works driver versions.

The original Karlson 15" enclosure developed in 1951 when tuned ~1/2 octave lower than normal as Exemplar, does make imo a very good sounding subwoofer using Altec (I've only tried 416A) - the downside is that the low end response is pretty much dependent on rear chamber bulk and system tuning so a skinny tapped pipe might have a lower cutoff for the same bulk.

Exemplar
An externally hosted image should be here but it was not working when we last tested it.


here's my lone K18 that's not much bulkier than K15 - it has typical Karlson punch and is good as a 2-way with the slotted K-tube tweeter.
An externally hosted image should be here but it was not working when we last tested it.


it will be interesting to see what X says the Karlsonator's arrangement can do
 
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the Karlsonator by Greg B should be an improvement over a simple 1-fold pipelike the one I made with one 4'x8' sheet of plywood loaded with a 295-070 15" woofer. That pipe had tuning ~30Hz, F3 half space ~40, F10 half space ~30, and relatively flat response in a corner to 32Hz

this idea was suggested by "nineleaves" - the "inverted T" or mini-K aperture may have some virtues other than looking cool.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 

GM

Member
Joined 2003
xrk971 told me that this is actually more of a tapped horn crossed with a Karlsonator......

Greets!

Hmm, this is a bit of a hybrid since it's an expanding horn mass loaded by a short vent [MLhorn] loading a reverse taper line [TQWT/P].

As such, with a vertical driver array I'm concerned about the potential for an uneven enough acoustical loading to cause some drivers to 'hog' the power with disastrous results.

I'm not sure that any speaker program can sim this pressure differential accurately enough, so 'caveat emptor' applies.

GM
 
As such, with a vertical driver array I'm concerned about the potential for an uneven enough acoustical loading to cause some drivers to 'hog' the power with disastrous results.

GM

Hi GM

I am planning to use a 4-channel amp for each speaker, so each driver will have it's own amp. Will this help for the uneven power distribution? If necessary I could separately adjust the power to each driver as well.

Thanks,
Deon
 
After some of the replies, I decided to throw another few designs in for further discussion.

Here is the first. It is the same as the original design, except that it is a full horn (not a ML-horn) + Karlsonator design:

An externally hosted image should be here but it was not working when we last tested it.


Next is a design similar to the original (ML-horn = Karlsonator), except that the slot is not at the bottom:

An externally hosted image should be here but it was not working when we last tested it.


And the last is the same as the previous one, but is also a full horn design:

An externally hosted image should be here but it was not working when we last tested it.


Let the comments begin. :D

Deon
 

GM

Member
Joined 2003
I am planning to use a 4-channel amp for each speaker, so each driver will have it's own amp. Will this help for the uneven power distribution? If necessary I could separately adjust the power to each driver as well.

I don't see how, drivers draw current based on the signal and acoustical loading with the signal of course dominating, so one driver could be overheating trying to excurse the amount the signal demands [extremely over-damped] while another can be severely under-damped, so while the former is burning up, the other is 'flapping in the breeze' so to speak and I've learned the hard way that at high power, the differential required to become disastrous can be quite narrow.

Ditto WRT the variance between driver specs, which I forgot to mention earlier.

GM
 
I was thinking about something that xrk971 and other said. I already have two pairs of drivers, so maybe this design will work well enough for my needs (for now). Not that I want to take away from the discussion of the other ideas, but here is my idea for just two drivers per side:

An externally hosted image should be here but it was not working when we last tested it.


It still uses a Karlson slot in front of the drivers for that wonderful Karlson slam, and the rear wave loaded into a full standard TH, so it remains a TH/Karlson(Karlsonator?) hybrid. What do you think? xrk971? I am still very curious to see what you sims will reveal. :)

Enjoy,
Deon
 
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Founder of XSA-Labs
Joined 2012
Paid Member
Sorry I have been really busy with another project so have not had a chance to model this. For 4 drivers along the length you will have a phase issue as GM points out. Two may still work but 4 large drivers are too far apart to be able to excite the same part of the wave unless they were phased differently somehow. It is not as simple as scaling a regular Karlsonator because the profile you are looking for is so different. However, maybe the first thing to try is to take a regular Karlaonator and scale it with a sivglenor maybe dual drivers to see how it looks.
 
sivglenor?

Sorry I have been really busy with another project so have not had a chance to model this.....However, maybe the first thing to try is to take a regular Karlaonator and scale it with a sivglenor maybe dual drivers to see how it looks.

Hi there X: Tried Google, Bing, Ebay to find a description of a "sivglenor", without result. ...regards, Michael
 
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I've always thought Karlsonator the mini version of this tallboy K18...

Nope, never actually built it (lack of space and time and money).
Who will be first to throw good wood at pure untried madness?
 

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Sorry I have been really busy with another project so have not had a chance to model this.

No problem. Thanks for taking the time you have to reply already. :)

For 4 drivers along the length you will have a phase issue as GM points out. Two may still work but 4 large drivers are too far apart to be able to excite the same part of the wave unless they were phased differently somehow.

That is why my suggestion for the horn + Karlsonator with just 2 drivers, but here are all my 2-driver ideas.

First up my original 2-driver idea:

An externally hosted image should be here but it was not working when we last tested it.


Next up is the same as above, but this is a true TH + Karlsonator design. The rear drivers are connected out of phase with respect to the front drivers, creating a force-cancelling type of set-up:

An externally hosted image should be here but it was not working when we last tested it.


Lastly is the standard Karlsonator, but the height has been increased by 2.5x. Width and depth the same as the standard Karlsonator:

An externally hosted image should be here but it was not working when we last tested it.


I don't quite get the form and location of your Karlson slot, could you add a sketch of the front view, and some even very general dimensions?

Here is a basic sketch of how the slot will look. It will be the same as the standard Karlson slot, just stretched. This holds true for all the designs suggested in this thread:

An externally hosted image should be here but it was not working when we last tested it.


I hope that answers all questions. :)

Deon
 
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hi Deon - just showing what that simple type does - hopefully we'll get a nice response with the large Karsonators

+10

I am really hoping for some nice figures here. I understand that the 4-driver version might not be suited to something like a Karlsonator or TH style Karlson because of the delay, but how about a standard Karlson-like reflex? Here is a tall 4-driver Karlson idea:

The driver lay-out with the slot removed:
An externally hosted image should be here but it was not working when we last tested it.


The slot design:
An externally hosted image should be here but it was not working when we last tested it.


Here is the full design:
An externally hosted image should be here but it was not working when we last tested it.


Deon
 
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