"Enhanced" Anarchy tapped horn project.

Status
Not open for further replies.
Jump to Latest
A

aceinc

Member
Joined 2007
#1
I started another thread "Tiny Array of Ripoles" and in the discussions most people were trying to convince me to build lilMike's Anarchy based tapped horn.

I am considering that approach. For two main reasons I would like to change the design slightly;

  1. I would like a bit more SPL/efficiency per cabinet.
  2. Since this is a hobby, I would rather not just use cookie cutter designs.

In order to somewhat intelligently tweak the design, it would be useful to get the hornresp info for the existing design. Where can I most easily get this?

My thoughts on how to achieve my 1st goal is to either add another driver or use a 6" x 9" driver.

My goal SPL wise is 92 db for two cabinets side by side at 1 watt. If my seat of the pants calculation is right I need each cabinet to put out ~89 db. Based on my reading, the current design is 86 db, so an additional driver should get me to ~89 db.
 
#6
bullittstang said:
6db comes from --- +3db for added speaker, and another 3db from lowering the ohm load. i.e. from 8 ohm to 4ohm by connecting them in parallel.
Click to expand...

My intention was to use two four ohm "cabinets" in series to yield an 8 ohm load. I suspect that were I to use two 8 ohm "cabinets" in parallel it would increase the sensitivity, but not change the total SPL available before max-ing out.
 
#7
If you're wiring in series, you won't change the voltage sensitivity. ie, if the amp put out 2v and that made the sub do 85dB, put another one in series and you've doubled the cone area (+3dB) and halved the current flow (-3dB).

Chris
 
  • Like
Reactions: NBPK402
#8
chris661 said:
If you're wiring in series, you won't change the voltage sensitivity. ie, if the amp put out 2v and that made the sub do 85dB, put another one in series and you've doubled the cone area (+3dB) and halved the current flow (-3dB).

Chris
Click to expand...

To me that means the only benefit is that you can double the SPL at twice the power, without increasing the sensitivity.

So one cabinet with 2 - 4 ohm drivers wired in series will yield the same sensitivity as one driver in the same cabinet, but will have an additional 3 db of "headroom", correct?
 
#11
FWIW, I built a pair of these Anarchy TH's, and after a little domestication, I'm happy with how well they work in my system. Attached is a picture of one. Sitting on top is a bookshelf speaker and a plate amp.

I used a minidsp as a low pass, cutting off the wild peaks above 100 hz or so. Each one is powered by its own class D plate amp, with variable gain, phase, and crossover freq.

Good luck on your variation. 🙂
 

Attachments

  • system.jpg
    system.jpg
    38.7 KB · Views: 579
#13
OK, it's been a long time since I worked with Hornresp. I downloaded v42.40 was able to get the file from AudioKarma loaded. It yields a plot similar to what I expect, a sway back horse with a low peak at 205hz and a larger peak at 75 hz, and all kinds of noise above 100 hz.

I see how I can add additional drivers, but how do I place them in the horn so they are side by side?
 
#16
Here are a couple of shots of actual (near field) measurements for my Anarchy TH's.

The raw (un-filtered) measurement shows the huge swings above 100 Hz.

The next shot shows the measurements with the plate amp set at min and max crossover frequency settings (40 hz and 200 hz). Closer to what would be usable, but the nasty peaks above 100 hz were still audible.

That's when I decided to add the minidsp as a low pass, with 48 dB/octave rolloff. Took a lot to tame it, but now the bass is clean, and more enjoyable. 🙂
(sorry, but I never made a measurement with the minisdp in the equation.)

Moral of my story is that the hopelessness at the outset was only temporary.

Sounds like the 70 hz peak in your model is different than what I measured on my system. You might run through the thread with the hornresp file and see if there were any updates or refinements. Also, see Brian Steele's comments above regarding the syntax.
 

Attachments

  • SPL_raw.jpg
    SPL_raw.jpg
    63.4 KB · Views: 501
  • SPL_Fx.jpg
    SPL_Fx.jpg
    49.9 KB · Views: 482
#19
aceinc said:
To me that means the only benefit is that you can double the SPL at twice the power, without increasing the sensitivity.

So one cabinet with 2 - 4 ohm drivers wired in series will yield the same sensitivity as one driver in the same cabinet, but will have an additional 3 db of "headroom", correct?
Click to expand...

It will yield the same voltage sensitivity but at twice the impedance or half the power the
pair is 3dB more efficient. Woofers do not act like resistors due to the acoustics involved.
Headroom should be +6dB due to twice the VD and the relation to power is VD^2.
 
Status
Not open for further replies.
Top Bottom