Friday, July 20, 2012, 17:17
Posted by Anders

After much iterating and many hours swapping data between hornresp and cad screens a THAM18 proposal is here, as per previous designs the THAM18 uses the now rather familiar THAM folding but in a another form, hence the name.

The design of the THAM18 posed challenges not previously encountered, preferring small yet capable designs I would have liked to see a more compact THAM18, but the laws of physics dictated differently, also taking into account that the relative cone stiffness is somewhat decreased when using lager drivers.

The goals set for the THAM18 was that it should provide something the previous THAM designs could not offer, but as always there are no free lunches, the price in this case is size.

Any revisions or alterations that may come along for this documentation (drawings) will most likely not change very much from what is presented here as far as the new concept folding goes, there might also be some detail drawings turning up within short, brace positions in side view and driver baffle are some examples of this.

Since the THAM18 is a new creation in progress there are still some areas of uncertainty, the front coupling between driver and horn, and the rather long rear horn segment along the height of the enclosure,
only a build will answer if these areas pose any real issues, my current thinking that they don't, but i feel it only fair to let you know.

The default driver of chosen for the THAM18 proposal is the FaitalPro 18HP1060, as usual questions regarding other drivers will not be answered, no offence intended but I would be doing little else if that was the case, instead i refer you to the hornresp software, all the data you need is already provided.

This is the THAM18 development proposals it stands right now (not the final release) :

Simulation input :

Simulation result :

Being a work in progress what you see here might not reflect the final result, but it should be pretty close.
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Simulation comparisons of the THAM family models. 
Saturday, March 31, 2012, 12:48
Posted by Anders
Thought I'd better sum the sims up, below you'll find comparisons between simulations of the all the current THAM models including external volumes.

The THAM15 (187 l) and THAM12 (96.25 l) :

The THAM10 (60.75 l) and THAM12 (96.25 l) :

And just for fun, why not compare David and Goliath :)
The THAM6 (42.18 l) and THAM15 (187 l) :

If I could figure out how to overlay the THAM10, 12 and 15 graphs you would see that these is a method to the madness, each models differs by approx 10Hz in response depth.

And finaly a comparison in size to a fairly standard 218 subwoofer, choosen for it's comparable sensitivity and familliar size :

Here are the different THAM series direct links

Professional application designs :





Home application designs



Simply choose, print, build and be amazed :)

oh, and yes, there is something else in the works, as always, the TPAM10HTL, meant as an as a alternative to the TPAM10HT where the "L" stands for "light" as it uses a 30Hz tuning for home cinema use instead of the 20Hz used in the TPAM10HT.
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Thursday, March 15, 2012, 21:02
Posted by Anders
It's roughly half the size of the THAM15 (35x50x55cm) but is still granting useful 50Hz response with a 100dB/W/m sensitivity flat on open ground, the driver chosen as default example is the Beyma12LX60V2.

Once again Johannes Rodin is to blame for yet another new THAM design seeing the light of day, his first words where "- it's tuned to low and the enclosure is to big" but eventually he came around to seeing it my way :)

If you csn not find your driver below and have questions like "will this driver work?" then please try yourself using the data provided above and simulate it using hornresp, if it works, please let me know, all the info you need to find out if your driver will work is already provided here.

The drawings will be updated, and the original Beyma 12LX60 will be added to the simulations, I have seen it and it looks just fine.

The designproocess :

Frontview :

Internal dimensions :

Braces and their postions :

Driver Baffle (note that the cutout is driver dependent) :

Assembly control dimensions :

Hornresp dimensions :

Default driver example Beyma 12LX60V2 :

hornresp simulation input data :

Flat on open ground 1W 1m Beyma 12LX60V2 :

Along a wall 1W 1m Beyma 12LX60V2 :

In a corner 1W 1m Beyma 12LX60V2 :

Max SPL Beyma 12LX60V2 :

Groupdelay Beyma 12LX60V2 :

System volume :

Phase :

Impedance :

Cone excusrion :

Please note that I do not judge the following simulations, this should be left to the potential DIY'er, but it goes without saying that some simulations shows better results then others.

Some designer notes - This design prefers high BL (about 20 or higher) and low QTS, but i guess thats a given to anyone visiting this page, right!* :)

*/ I try to make it a point that not only hell bent speaker nerds should be able to DIY a decent tapped horn.

Other driver examples all simulated in 1PI environment :

B&C 12PS100 :

B&C 12NDL76 :

B&C 12NW76 :

B&C 12BG100 :

Beyma 12P80Nd :

Faitalpro 12FH500 :

Faitalpro 12FH510 :

Fatialpro PR300 :

Faitalpro 12HP1020 :

RCF MB12N407 :

RCF LF12G301 :

RCF LF12N301 :

RCF LF12N401 :

18sound 12NLW9300

18sound 12W500 :

18sound 12W700 :

Beyma 12LX60 :

BMS 12N804 :

BMS 12N630 :

Eminence Kappalite 3012LF :

Eminence Definimax 40012HO :

JBL 2204H :

JBL 2206H :

JBL GTi1200 :

JBL 2020H :

Precision Devices PD 121 :

Precision Devices PD 122 :

Precision Devices PD12SB30 :

Precision Devices PDN12MH25 :

And finaly some build pictures that i got sent to me :

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odd couple 
Tuesday, January 10, 2012, 22:21
Posted by Anders
So I ordered myself a pair of 2" Tangband "fullrange" speakers thinking that I could make something nice and inconspicuous looking system for my office computer, but that's not exactly what happened.

It just so happened that I had a couple of JBL 2386 2" horns collecting dust in the storage room, I realized this was not quite an obvious match, rather the opposite in fact.

Well, needless to say this unholy union needed some tweaking...

This did the trick, these horns are very fun to listen to, the resolution they provide crossed over at 140Hz to the THAM6 residing under the tv rack is just amazing, although the frequency response is not exactly "ruler flat" :)

Not scoring very high in the WAF category, but then again, I don't have that problem :)

They look like good old stadium horns they use at the tracks :)

Not that far off actually, these horns, the JBL 2386's where actually intended for clustering applications in arena type environments, their dispersion pattern being 40x20 (HxV).

So they sound nice and clear with great resolution down to approx 300Hz, they are more then loud enough for apartment use, and they cost me a whooping 230sek each :)

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TPAM10HT (see also the TPAM10HTL) 
Monday, September 5, 2011, 21:13
Posted by Anders
Upon request i have now designed my first true sub intended for home theater use, or as a complement to stereo speakers typically reaching down to approx 50Hz.

If this design and application is something you are looking for I strongly recommend that you take a look at the TPAM10HTL, which was developed shortly after the TPAM10HT, it offer significant benefits apart from not reaching the 20Hz marker.

As usual I got a lot of help from my friend Johannes Rodin who also helped me out on the THAM series designs.

The TPAM10HT design principle, lovingly referred to as "tapped pipe" allows for relatively compact outer dimensions while still reaching it's goal of simulated in room 20Hz reproduction.

TPAM10HT contains a lot of compromises in order to reach it's performance with approx 80 liters of system volume, one of which is the driver depth (max 120mm), the other is the sound pressure level, even if i believe it should be sufficient for most users.

The TPAM10HT has been simulated in all positions and with two drivers i found to be of interest, but there might be more suitable drivers out there.

Please note that I can't answer questions regarding the suitability of these other drivers, no disrespect intended but I simply do not have the time, instead please use hornesp. and the data provided here to find your best candidate.

This is the TPAM10HT :

The cutout geometry shown in the drawings above is tailored for this driver :

Product Line: Peerless Gold
Model Number: XLS-P835028

Be aware of this if you choose to go for another driver.

TPAM10HT system volume and principle :

Simulation results for the Peerless XLS-P835028 at 1W & 1m :

XLS-P835028 When positioned in a corner:

XLS-P835028 When positioned along a wall:

XLS-P835028 When positioned freely on the floor:

XLS-P835028 Electrical impedance:

XLS-P835028 Cone excursion:

XLS-P835028 Group delay:

XLS-P835028 Impulse response:

I also found the B&C 10NW64 to be a candidate, below you will
find the simulation results for the B&C 10NW64 at 1W & 1m :

B&C 10NW64 When positioned in a corner:

B&C 10NW64 When positioned along a wall:

B&C 10NW64 When positioned freely on the floor:

B&C 10NW64 Electrical impedance:

B&C 10NW64 Cone excursion:

B&C 10NW64 Group delay:

B&C 10NW64 Impulse response:

These are my recommendations for now, they will both fit in the TPAM10HT but please note that the cut out geometry specified in the drawings are tailored for the Peerless XLS-P835028, so some adjustments might be necessary if you go for the B&C 10NW64.

If the driver of your choice (outside of those above) can't be fitted within the 120mm depth restriction the box may be widened, but doing this will void any of the results above and I would strongly recommend a simulation prior to build.

This design has not been built and tested in real world conditions yet, results will be posted when this has been done.

Finally some build pictures :

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