Tapped Horns

While reading the forums, I got aware of someting called "tapped horns". It is an old enclosure principle which was rediscovered lately and now better understood and interpreted by Tom Danly. Here is his very interesting whitepaper white paper on his companys web site: Danley Sound Labs

The Eminence Horn

After reading this thread I was wondering if I could use one of two 15" I had left over from the Klipschorn. After some back and forth, an obsolete Eminence type EPS15-500 (Xmax 6,4mm) looked most promising. Even though the Xmax is limited I gave the following simulation a try (Note: as a direct replacement you can also use the current Eminence Kappalite 3015LF (Xmax 9,6mm), Eminence DEFINIMAX 4015LF (Xmax 9,0mm) or the MTX Audio T7515-04 (Xmax 16,5mm). Many others will work as well - just give them a try with hornresp).

 

The predicted response:

EPS15-500_v3_SPL

 

The parameters of the simulation:

EPS15-500_v3_PAR

 

The excursion simulation:

EPS15-500_v3_EXC

 

Regarding the room gain I like the idea of EQing the response down and gain some headroom.

The Eminence I'm using will reach Xmax with only a little above 15V @ 20Hz (115dB should be fine anyways).

 

This gives you an overview on the folding:

th_v1

 

And this is what it looks like during building:

TH_innen_1

 

Except the inner bracing, which were 16mm, the thing is made from 22mm MDF. All connections are glued and screwed. It took me a weekend to build it.

TH_innen_2

 

Here is the baffle cutout for the 15" speaker.

TH_innen_3

 

This is before sanding:

TH_zugeschraubt

 

This is my old Eminence EPS15-500 in place. As I pointed out, the Kappalite 15LF will fit also (very similar response, more max SPL due to higher xmax - 9,6mm insted of 6.2mm).

TH_speaker

 

When I brought it into my room first, I thought: Oh my god, this thing is big.

TH_liegend

 

Here it is in my room. After errecting it in the corner it still looks large but not as bad as before, when it was laying in the middle of the rool. Paint will be applied in spring and of course, If I still like it then. The mouth points toward the left hand side.

TH_aufgestellt

 

In the evening I did some testing. I heared some music and watched a movie. It sounds very effortless and goes deep down. Great for HT and music.

 

I also made a less lall version of the TH (230 vs. 244cm). Low end is just a little compromised. Here is the comparison of predicted responses:

EPS15-500_v3_SPL_230_vs_244cm

 

Both plans can be found in the download section.

 

 

The Tangband 30Hz Tapped Horn

I listened a lot to the first tapped horn I built for the 15" Eminence I had laying around. What I must say is that I like the bass of the unit a lot. Is sounds very accurate and precise. The sound is what I would decribe as effortless and easy. The best bass I had in the system. That's for shure.

After listening some evenings with my friends, one of them wanted to know if it would be possible to build something like that but smaller (better WAF, what the one for the 15" doesn't have). I serarched a lot for possible drivers, and to make a long storry short, I ended up with a 6.5" Tangband. Since they are so cheap and to have some more headroom and flexibility in regards to placement I built two units for this guy (and for my pleasure):

Mini-TH_1

Note: Access panel to cover the speaker is not installed on this picture (it will be mounted on the aluminum rails).

 

For testing I placed them simply in between my mains, right next to them. Especially compare them (65l net) to the 15" TH (430l net) in the right hand corner:

Mini-TH_2

 

I was very curious on what they are capable of. And after a weekend of listening I have to say that the result is way beyond my expectations. Sure, the big one goes deeper and louder, but they just sound great. Very well controlled and smooth, down to the lowest registers. I found myself several times not believing that only the two small TH's were running (but the big one and the Klipsch were disconnected). They are able to produce very remarkable volumes, much more than usually required for listening music as well as HT. They are capable to keep up with my mains in every way.

 

Here are the input parameters:

Mini-TH_PAR.jpg

 

Here is the predicted response:

Mini-TH_SPL

 

This is the theoretical SPL in quarter space at 20V where Xmax (11.5mm !) will be reached.

Mini-TH_max-SPL

 

As I said, I built these two for a friend of mine. Since I fell in love with the Tangbands, I already ordered another 4 of the speakers to built some more TH's like that.

Finally an incredible bang for the buck (at least in my eyes and for my purposes). Very easy to build (I glued them togeter in my living room) and a lot of fun. For an amp I used the unused rear center amplifier from my HT amp. The xover is a 30 Reckhorn unit. Total investment for the speakers, the MDF (16mm) and the xover approx. 150 Euro.

 

The plans as well as a design util can be found in the download section.

 

The Tangband 38Hz Tapped Horn

I simply could not withstand to build another pair of TH's with the remaining 4 drivers I'v got. This time the goal was to build some TH's which will extend a little further up match to the conical midbass horns. Therefore I choose to make the horn shorter and crossing at 100Hz will hopefully be possible.

Here are the input parameters:

Tangband W6-1139G, 38Hz TH_PAR

 

Here is the predicted response:

Tangband W6-1139G, 38Hz TH_SPL

The response starts to rise at 100Hz with approx. 18-20dB/oct. The irregular peaks at 180Hz and 250Hz are predicted not to be stronger than the range below 100Hz. Others who built TH's also reported that the predicted peaks were not as bad in real life. My guess was to xover at approx. 100Hz and so to be able to get an usable response to maybe 100Hz or even a little beyond. Note that the design includes the use of 4,7mh coils to even out the response. I will use these:

coil

They are wound from 1,32mm dia. copper wire and have a Rdc of 0,26 ohm.

 

 

Some pics of the TH's I took while building them:

Tangband_38Hz_00 Tangband_38Hz_01

I had to make the mouth opening a little larger than initially desired because I wanted to be able to install the driver without a removable panel as I did on the 30Hz TH further up. I changed the simulation accordingly in Hornresp but the difference in response was neglectable.

This time I also used a little thicker MDF (19mm for all panels) and additional bracing. Actually I was surprised how much the 30Hz TH's flex when turning up really bad. I simply did not believe that this could happen with such small driver.

 

Tangband_38Hz_02

This is how I folded to get the 15cm longer S12 (over S34) into the box.

 

Tangband_38Hz_03

Note the braces I installed to avoid vibration and flexing of the panels. The top of the box has also a brace connection it to the inner divider.

 

Tangband_38Hz_04

Done. Sanded and wired with terminals and speaker installed.

 

Tangband_38Hz_05

A close-up of the driver which fitted perfectly.

 

The plans can be found in the download section.

 

In the meantime the 4,7mH coils are installed and I must say that I like the small ones a lot. Actually, now my Klipschorn moved out of my living room. Integration is much easier with the TH's compared to the Klipsch corner horn.

Later I also built a double folded version of the 38Hz Tangband TH because it better fits into my room:

Tangband_38Hz_klein

Here you can see it compare to the initial single folded version. An advantage of it is the stiffer enclosure.

Tangband_38Hz_single_and_doublefold

Parameter wise it is completely identical but it is double folded. The plan for this TH is also in the download section.

 

The Tangband Cinema Sub Tapped Horn

At the end of 2010 I felt some itching in my fingers. It was already some time ago that I had built some boxes. You have to know: For me the experience to actually "manufacture" someting is a great deal in the overall effort. Just DIY!

By accident I found a sale on the Tangband's W8-740P. I ended up buying four of them (you never know...). Later I realized, that there is a commercial product which uses just two of them in a home cinema type TH. More over, enough detailed information of this design was available on the web. All this qualified it for me to be a nice DIY project for the next weeks and months.

On the design I liked the concept of two drivers mounted in opposite directions wired out of phase. This can help to cancel out speaker suspension system non-linearities. Last but not least I was curious to see what a design of the "inventor" Tom Danley - or at least a close clone - is all about.

I never did a Hornresp simulation of these TH's, however I'd like to have on. I'd appreciate any input in this regard!

Following you will be able to see how I actually built these TH's:

TH-SPUD

 

After the plans were finished, I made some thoughts on how to make the built somehow efficient. I decided to prepare a template to transport the design to the sidewalls. Later this template was also used to drill holes for the screws into the sidewalls as well as for milling the openings for the access panel and the mouth opening with a router.

TH-SPUD

 

With the holes drilled for the screws it is quick and easy to position the pieces on the sidewalls.

TH-SPUD

 

Fist one

TH-SPUD

 

one more picture of it...

TH-SPUD

 

With the aid of the template you can drill both sidewalls. You just have to flip it over.

TH-SPUD

 

I also added the openings for both access panel and mouth into the templates. Here the template is visible from the bottom side (one side is white, the other is brown).

TH-SPUD

 

With the help of the ring for the router I was able to make the stepped opening for the access panel with my template.

TH-SPUD

 

one more pic of the router details... (I have to get a better router btw. This cheap Chinese thing consumed most of my time for setting it up correctly.)

TH-SPUD

 

One more pic of the open TH.

TH-SPUD

 

The sidewall with the access and mouth opening put in place (not yet glued)

TH-SPUD

 

Detail of the access opening:

TH-SPUD

 

And one more picture...

TH-SPUD

 

Painting the inside: You can regard it as a waste of time, but I wanted it like that :)

TH-SPUD

 

And another picture.

TH-SPUD

 

Some final sanding before applying the the first layer of paint with a roll.

TH-SPUD

 

Both TH's closed and ready for the fist layer of paint (rolled on).

TH-SPUD

 

And another picture.

TH-SPUD

 

And another picture.

TH-SPUD

 

This guy is me preparing the paint for the first layer to be rolled on.

TH-SPUD

 

I decided to use Warnex to coat the TH's. Warnex is a professional loudspeaker enclosure coating. It is water based and can therefore very easy be handled. Warnex can be applied with a simple automotive under body coating gun. The paint is actually like pudding and must not be thinned in order to achieve the surface structure. I mixed white and grey RAL7016 in a ratio 1:2.

TH-SPUD

 

Detail of the can and the mixing ratio I used.

TH-SPUD

 

I needed approx 2Kg to paint both TH's.

TH-SPUD

 

Here you can see the surface structure.

TH-SPUD

 

Access panels:

TH-SPUD

 

Detail of the access panels:

TH-SPUD

 

Another detail of the surface structure. After only a day the paint is entirely dry.

TH-SPUD

 

Backside of the connection panel. I used two speakons out of phase. So you can easily alter the polarity if required and you can also run both TH's in parallel on a single channel of your amp. I will run them as stereo subs on my Yamaha P2500S amp.

TH-SPUD

 

Access panel in place.

TH-SPUD

 

Both TH's almost ready. Only the grills of the mouth are missing.

TH-SPUD

 

And another picture.

TH-SPUD

 

And another picture.

TH-SPUD

 

Here are the grills: Laser cut from stainless steel and painted with Warnex.

TH-SPUD

 

Detail of a grill with Warnex structure.

TH-SPUD

 

Finally in my room: Left channel.

TH-SPUD

 

Here you can see the grill installed.

TH-SPUD

 

And another picture.

TH-SPUD

 

Last but not least the right channel.

TH-SPUD

 

This is how they measured in my garden. Both of them running in parallel, standing next to each other. Mouths facing towards the microphone. Buildings were more than 10m away. Microphone was on ground level on a concrete plate approximately 8m away. Measurement was taken at uncalibrated level and with some "serious" SPL, not only 1 watt".

TH-SPUD

 

The Klipschorn and the Eminence TH are gone now. Currently the new TH's run crossed over to my conical midbass. Even if the xover adjustment capabilities of my current setup are limited (old Albs Sub25BB) but with some EQ applied, integration to the midbass fits better than before. Even though I think this is a point which could be further improved in the future. Besides this, the sound of these TH's is relaxed and effortless down to the lowest registers with in my eyes insane headroom.

Please note: I built these TH's based on information one can find on the web. In addition I made changes and modifications to the design so it fits my personal taste. These TH's are neither copy's nor aren't they meant to be copy's of the original product. Finally I will not make any plans available.