Friday, April 23, 2010

Good Times, Bad Times, part III

As most of you know I am finally getting close to something resembling a finished speaker. After literally ten years of all types of horn "sculptures" (see VSAC 2008 for an example of something built on site), I am feeling like I can see the end... I might even put binding posts on something one day...

The line is planning to run from Exhilaration I through V. I still have some work to do on which compromises are best for each price and size point, but here is some work done on what I think will be EX III.

So here is some of the good: The horn shown above (it is now 1.25" thick all the way around) went into the system about midnight last night. I hooked it to the 304TH and just threw in an old Nick McKinney signed Lambda Acoustics Apollo 15". Awesome! I love bass horns.. that snap.. and the clarity... so far, so good..

And then some BAD came along. My ancient (I think 15 year old) laptop crashed. Ugh. No more measurements for me. (They don't make any decent software for Mac. Parallels and such have not loaded properly. Anybody have a junker PC based laptop they want to trade? It can be as old as Windows '98.. or have any ideas on where you source something like that?)

Anyway, so then I just got out the signal generator. My ears told me it was playing very low. I had only simmed as 65Hz. The sweeps had me scared at first. I heard a very light dip around 120. I was afraid it was going to drop. Back to full tilt at 100Hz... still strong at 80... 70... 60!! 50!!! and then straight down... WOW.. dude... 50 Hz... so then I juiced the volume.. I had to... shaking the walls... screws on shelving rattling.. awesome...

and then I realized it was past one AM... man, time for bed...

The next comparison will have to be straight versus backloaded JBL scoop style cabinets. The footprint is *much* smaller for the scoops, but the sound? I dunno.. maybe.. it is an eight or nine foot path curled up inside there..


  1. Very nice work.

    Big horns rock!

  2. Very cool! What is the depth of that big horn?

  3. Hey Josh...

    It is a 65Hz tractrix - 47" long horn and a 9" deep back chamber. I am still stunned by the output below Fc. Maybe I need to run my numbers again? (ha!) It was modeled for a 515B, but as we all know, a good horn is a good horn.. and you learn when you put a driver on it..


  4. man, that's SO cool...
    you are the man... again...
    i ran numbers for months on a 65Hz tractrix, on i forgot how many drivers, using something else, sim sez falling off @ 20db/oct from ~70Hz!
    and you got 50Hz! way cool!

  5. Hi Me,

    I really keen to try building something like this for my 15" woofers to replace the 360L onken cabinets they are currently in. Would something like this horn play from 50hz? to about 300hz well? Is there any chance you would be willing to share with me measurements/design of the horn?

    Best Regards,


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