tapped horn design

my mate and I did our first folded bass horn design, a tapped horn around the pd 186/2 and from our first tests we can conclude that it well outperforms a pd186/2 loaded super scooper.







smoothing 1/12, green is scoop, gold is tapped horn.
As you can see the scoop has an odd dip around 50Hz.. we're not sure; could have been the room (large woodshop) but the tapped horn didn't have this at all.

This is just a prototype; we need to re-do the dimensions because it barely goes through a door.

The fold for now is done with best sound quality and the least volume loss in the corners and smooth transitions. Next design we will try to maximize use of space.

The sound quality is superb. It goes deep down to 35Hz -5 dB! incredible warm, rounded yet punchy sound. The upper bass region from 70-100 Hz isn't as heavy as a scoop but we only want to use it from 30-80Hz anyway. That's what is was designed for.

The scoop sounds really harsh compared to the tapped horn. The upper bass is stronger as stated by the first measurements but when you A/B the two cabs when playing music through them there is an incredible difference! The tapped horn in one word is smoooooth and pretty fast. The scoop is harsh and slowy but has a bit more detail in the upper bass (but at the some time more fatiguing to my ear).

In stacks of 4 I can only imagine this thing will go down to 30 flat easily which is incredible, I couldn't believe horn resp and couldn't believe the measurements.

This tapped horn effect gives us double sd and excursion at around 40-50Hz which is the problematic region for this specific driver.

Overall I'm very impressed with the sound coming from this thing... and the crazy thing is that the prototype was built out of mdf :p

Proper measurements will be up when we get to measure it outdoors.


So one advice: if you want to try out tapped horns yourself.. just do it! Sounds really good!




Edited by hond - 05 September 2014 at 1:11pm

looks good but that's a lot of wasted space. IMO rounding the corners does absolutely nothing useful in subs and wastes volume too. the larger the volume of your horn the lower it will go. the only frequencies that the rounding will help are high frequencies i.e. distortion that you don't want a sub horn to transmit.

Also for a TH that is quite a short horn.

Back to the drawing board. Longer horn with no wasted space and a smaller mouth

Yeah sorry about that. Not sure if it's being negative though. After all this is the real world and we don't live in Disneyland 

Maybe I just don't like wasting wood

Hond, your measurements are the typical response of a Scoop so there is nothing-peculiar taking place there. A gentleman on this board offered outdoor measurements and, had the same decline @ 50 Hz. I have literally carried my laptop to outdoor events and measured such bins in which the cabinets began to decline below 51.7 Hz.

There is a big difference measuring a box in real-time versus using a simulation software as a means of reference.

Your low midrange will just need to work a little harder to make up the loss from 70 Hz onwards that your design does not offer with great efficiency as a Scoop.

Best Regards,