Melbourne members: Collaborative Tapped Horn Project

Melbourne Members:
Collaborative Tapped Horn Project

I'm planning a collaborative sub project for Melbourne members. Since tapped horns can't currently be simulated and the design is based on driver size and tuning, it's well suited to a group project.

This is my draft design:



Here's the idea:

I build the box, then we get together to try out different drivers, measure and listen, as well as have a BBQ.

BYO drivers (probably 400mm max diameter)
BYO food to share for a BBQ
BYO reference tracks (music & movies)

Each person who brings a driver will need to bring a mounting plate of 360 x 360mm size with a hole cut for the driver. The driver should be mounted in this plate. On the day I will drill holes in these plates so they can be quickly and easily screwed onto the baffle. This will make it quick to try out many different drivers.

Here's how I propose we run it for each driver:

1. Assemble
2. Measure response outside (probably do all of them outdoors one after another)
3. EQ with Ultracurve to get it flat
4. Listen to reference tracks chosen at the start (music & movies)

We'll probably start with some setting up and getting things ready, then lunch, then measuring, then trying them out indoors. We'd probably do it on a saturday from say 11am til say 6pm or so. At the end we'd probably open it up and play tracks people have brought along, or just have a good yak.

Date: TBA (I'm aiming to run this day in about 2 months around May.)
Time: Probably 11am - 6ish pm

Please post here to register your interest in attending, and please also mention which driver/s you are able to bring. If we don't have too many attending with drivers then I'll also open it up to others who don't have drivers they'd like to bring.

Background info:
Current DIY tapped horns:
http://www.diy.cowanaudio.com/th.html
http://www.speakerstore.nl/index.php?l=en&pg=12&prjID=33

Danley Sound labs white papers and spec sheets:
http://www.danleysoundlabs.com/knowledge baSE.htm
DTS20 tapped horn
http://www.danleysoundlabs.com/DANLEY_dts20.htm=

G'day Richard, how'd I know you'd want to fit in a 15"! The difference is that it can't be done with 2 sheets, and suddenly goes up to 3. Unless I do a bit of a hack job and keep the width the same, but squeeze the 15" in. I've thought of a way, it's a bit ugly and awkward, but workable.

Where did you find those suggestions on parameters?

Hi guys! To keep this thread short and to keep it about the praciticalities of organising the day, I've started a new thread:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=97674

Please use the new thread for discussing technical aspects of tapped horns. I want to avoid this becoming a long thread that anyone who wants to come will have to read through.

Here we can discuss:

* who is coming
* organising stuff - details of how we run the day
* issues like drivers you want to try, if they will fit in the box and so on

There may be some overlap with the two threads.

any other takers?

any other takers?

Richard, definately interested in a reference. I have a Rythmik single 12" sealed kit which should arrive in the next 2 weeks and was going to use that as a reference. I have a crappy 70L box (unbraced) which I can use. The only problem is that I also wanted to try the Rythmik in the tapped horn. This would prevent an AB comparison.

Considering it's just one sealed 12" it's not a fair horse race, but I figure it's a hard one to beat in terms of SQ being a servo sub. My particular objective is actually to match the SQ of the servo with an otherwise lesser driver so that I can use my existing subs WITH the Rythmik.

If you'd like to still build a reference as well, by all means go ahead. We could have fun comparing it to the Rythmik, or we could use them together as a reference to get more juice to compare with the beastly tapped horn. Or we could use it to AB compare each tapped horn.

Your thoughts?

BTW if you do build a reference with 2 x XLS, the simplest option would be to push pull mount them in a single box (one magnet facing out and drivers on opposite sides of the box). Volume picked to get Q of either 0.7 or 0.5 depending on how big. Then we use Ultracurve to get it flat. Saves you building two boxes, the opposed mounting will mean a simple 18mm unbraced or moderately braced box will be fine and you won't have to build a LT. I've found that two drivers mounted in this way have an acceptable amount of vibration in a box that vibrates too much with just one driver. You just make the box tall and slim (probably just one sheet of 1.2 x 2.4m)