TH-Micro - a 6,5" tapped horn

[martinsson]

Hello

I want to share a small DIY project with you, small being the big thing about it






More info and pictures can be found here :

Martinsson`s Blog

Best regards // Anders Martinsson

[Brian Steele]

Looks great. Did you account for the shading effect of the driver's structure when mounted in the horn's mouth like that? Some quick experiments with my POC suggest that the frequency response can be significantly impacted for a small-mouth design if this isn't taken into consideration.

Also, if a removable panel is included on the left side, this would make it a bit easier to mount the driver.

[j.michael droke]

Hi there: Fabulous job on the TH subs and appreciate your sharing the dimensions, Hornresp inputs, graphs. Would you comment on the Xmax of the simulations and the driver Xmax specifications? Your listening observations are valuable also. ...regards Michael

[FlipC]

Pretty sweet mate.

[martinsson]

Thanks for all the comments, I'm still learning about how they work, how they should be processed and what their strengths and weaknesses are.

This far I have not detected any major drawbacks of this design, but is is small and as such it's performance is limited accordingly.

The small cone area does bring along a bigger difference both in time and spl between the path loaded and direct radiating part of the sound generated, this characteristic manifests itself more at greater listening distances.

I goes deep enough for most types of music, and it does a good job as a movie sub where it adds nice distinct impacts and atmospehre.

In music it does roughly the same thing, it makes small speakers sound bigger, and if you give it enough power it can even give the listner a physical sensation, not bad of a single 6,5" driver.

The soundquality is very nice, they have a distinct, thick and organic sound that I think is the signature of TH designs.

The usefull response i would say is roughly 35-120Hz, wich i think is ok when looking at this little box on the floor, there might be (should be) dips and peaks in the frequency response that my RTA messurement can not detect.

I right now I was asked the question "can you live with this on a daily basis?" then the answer would be - yes!

Did you account for the shading effect of the driver's structure when mounted in the horn's mouth like that?

Sort of, you can see on the drawing that the last step of the folding takes a bigger leap areawise, this step is rougly equal to that of the projected area of the magnet structure.

But there still is a local compression at the driver, and maybe your sugestion would improve the design.

Would you comment on the Xmax of the simulations and the driver Xmax specifications?

Having oserved the cone excursion during program playback this does not seem to pose a problem, i regard the spl capacity as suficient for most occasions, but thats just my happy amateur opinion.

I do recomend a high pass filter at ~28Hz 24dB/Oct when listening at higher levels.

If someone decides to build one of these, please let me know.

[d to the g]

What would be the effect of having the driver turned the other way? Less susceptible to little fingers that way.

[martinsson]

What would be the effect of having the driver turned the other way? Less susceptible to little fingers that way.

If you look at the drawings you can see that the depth required for this type of mounting is not enough, unless you put some distance rings in there, but even so i fail to see how this would make the driver more protected, maybe i misunderstood you.

My suggestion would be to put an acoustically transparent protective grille in the opening instead, i intend to do so sometime in the future.

Due to it's small size this sub finds it self equally at home in in the car, at the computer or even in the kitchen, needless to say the WAF is rather high.

[ThyDntWntMusic]

i might have to make a couple of these and see how they go

alternatively I'll just design my own

either way, I've been meaning to try some small tapped horns for a while now!

[Circlomanen]

http://www.hififorum.nu/forum/topic.asp?TOPIC_ID=79615

Its in swedish but there is always pictures.

[Havoc08]

Very nice !

I might duplicate that, but was wondering if the peerless sls 6,5 would work in your horn or if it fits?

Europe Audio

Also, the insane frequency response above 100hz is inherent to horn designs as I have understood it (or the pattern at least). Could you dampen it with wool or similar for a more smooth response up to maybe 150-200 hz?