Reed Exodus Anarchy 25hz Tapped Horn - Page 2

There's a patent pending. Post #1260 here:

http://www.avsforum.com/avs-vb/showt...6#post17552206

I don't know if the idea is legal or not, but it's worth checking into methinks. Better safe than sorry.

Measurements? They're still on my laptop, which is still in the car....

I left radman12's place after 1 AM Friday night (we did the last outdoor measurements around 10:45 ), but was busy with lectures and travel all day yesterday so I did not get anything posted. After an hour of prep, 3 hours of speaking, another hour or two talking to people afterwards, and 5 hours of driving, I got home last night after 8, had a beer, and pretty much fell asleep in the chair.

Will try to get things cleaned up and posted shortly.

While a flatpack is a nice idea, to be honest - this one is not a complicated build. The cuts are all rectangular and most of the joints are square. Skilsaw and straightedge territory.

There is no internal bracing (there is no need). For this reason alone, this is a SIMPLE build.

Yeh, I don't think this design falls within any legal issues. But I do believe the guy(s) that did this particular design should be compensated though as part of the purchase.

If anyone thinks there's interest in flat packing something like this, I'll call around next week and see what I can come up with. If i found the right company, maybe we could get a bunch of different models built. maybe dual 6.5's, a single 8" design, the 12" shiva, etc.

I have plenty of room to store all the kits and ship out as needed.

I think it's simple for a decent amount of us, but not for many other people. Heck, most sub boxes are pretty simple to build.


A cabinet maker might be able to buy the wood cheaper to cancel out some of the shipping charges.

It will sound OK if the driver will fit inside, but it is not a perfect fit.

The low corner is not quite as low (30 vs 25), and the excursion is not nearly as controlled.

Without knowing the Xmax of the driver, it is hard to predict when the bad noises will start, but if you're not planning to drive it too hard, you should be OK.

It would be awesome to see what the actual size of an 8" or dual 6.5" would be and what the performance would come out at. I am looking to try my hand in building some subs, just to build as I have always had an interest in wood working. Brings me back 20 years to building things in my grandpa's basement.

It appears the single 6.5" is a sub $200 sub, perfect to start out as you describe it to be a "Simple" build.

I'm hoping you'll load the Tang Band W6-1139SI in your own build and measure so we'll have comparative data....

Ask and ye shall receive.

Measured 1W 1M SPL is blue, modeled is red.



We measured outdoors over a driveway, so this was not a perfect 2pi measurement by any means. Ambient noise was ~50 dB, so >25 dB down from the measurement levels. This measurement is certainly adequate to verify the performance of the design. We are essentially flat (+/- 3 dB) from 25 Hz to 100 Hz. 2.83 V yields about 86 dB at 1M, which is very close to the prediction.

Drive voltage from amplifier was set at 2.83V into an 8-ohm resistor with my most accurate voltmeter. My equipment is probably accurate to a dB, and should be flat within the area I have presented. Measurements were made with REW using the equipment I have described elsewhere.

I also did a little experiment with HolmImpulse.

Measured SPL and THD:



2nd Harmonic:



3rd Harmonic:



Hmmm, it is a 25 Hz tapped horn design and the THD takes over below that, pretty much as I expected, and exactly as theory predicts. I did not bother with the higher harmonics - they were buried in the noise.

Planning to do exactly that. They are not a bad fit at all, but do run out of excursion a touch sooner.

Radman12's Tang Bands were currently deployed (and sounded great, they measured pretty good too), so we did not want to tear anything apart as a science project.

That graph's looking pretty sweet to me

Those are impressive graphs!

What is the Max SPL?

Well, the driver is rated at 100 watts, but hornresp tells me that 75 is a safe limit.

I measured a 1 W/1M SPL of ~86 dB in a quasi 2pi environment.

Putting on my thinking cap.....

75 -1 = 74 watts remaining
Log (74 watts) = 1.869
1.869 * 10 dB SPL per log cycle of power increase = 18.69 dB

So - after a little head scratching, the theoretical maximum SPL for a 2pi environment is about 105 dB at 1 meter, though in reality there will be some losses due to power compression and voice coil heating.

Add in corner loading and room gain, and it will do significantly better, but I am NOT going to pull that number out of my nether region and present it to anyone as a fact.

Remember - I chose "low" and "small".

GREAT now I have another sub to build for my current living room.

I have 4 NHT plate amps that have been waiting for a project. This is perfect for them considering they are 80watts each.

Be sure to get the NHT amps modded correctly. The factory highpass of 30 Hz might leave a little on the table.

Yeah, I will have to find the direction on that again.

Big, low, high SPL

lil mike, I believe those were the three characteristics with tapered horns you mentioned as picking two.

You mentioned that the anarchy's were wonderfull drivers. Does doubling them up do anything when you were running models? It would completely change the design around though, but can it go higher and deeper with a larger box?

Sure, it can. This would be a totally different design though.

The targets were ~85 dB 1W, below 30 Hz, and under 2 cubic feet. I got the first two, but definitely missed the third.

Multiple cabinets is the only answer to loud with the Anarchy or similar drivers if that's what you're after. Consider that 4 cabinets would only take up 12 cubic feet total, but in four pieces. This would provide considerable output with a lot more flexibility in placement when compared to a single large sub enclosure.

Are you saying we can not just put two drivers in the same cabinet? The cabinet size would have to double when we double the drivers?

The cabinet would have to be designed all over again around two of them.

The cabinet and folds would most likely have to be redesigned.

Pennygray have you played around with hornsrep yet? Its a complete time waister with the new sliders trying to optimize your design.

Someone over at diyaudio modeled a DTS-10 sized cabinet with two JBL car woofers
http://www.diyaudio.com/forums/subwo...n-2x12-th.html

I have too many things to waste my day. I will not be bothering with hornsrep too soon

With most other horn designs at least if the drivers are placed side by side and the cabinet width is doubled the end result is the exact same as building 2 separate enclosures. I don't see any reason why 2 drivers couldn't be placed in a double wide enclosure.
That being said I still think it's better making individual enclosures for added placement flexibility.

I should have my 4x8 CNC setup here in a week or two. I've got the completed gantry and rails right now. Just need some limit switches and time to run the wire harness.

i agree with z. the prior art is compelling. here is a patent from 1962.

t.d. claims that he was unfamiliar with the pruden horn when he made his filing. that's cool, but not a reason to grant t.d. a 17-year right to the design.



ok, now first image is busted, reattaching.

Prior art never stood in the way of Bose.
Whether or not a patent stands up ultimately depends on who has the better lawyers and the deeper pockets.

Found my first DIY project I'll be building two/possibly three, one for me and another/possibly two for my brother. I plan on using mine for a two channel system and my brother will use his for a HT setup. My brother has all in ceiling speakers and needs a sub that can hang with them. I think this will do nicely. I'll have to convince his wife to let us build a second sub for their HT eventually. Thanks Radman12 and Lilmike. This looks like an easy first build and I appreciated all your combined effort in putting this all together. Quick question, can this be built out of 1/2" MDF instead of the BB Ply?

i'm a little lost. what is the advantage of this design?

this design seems to do quite well for a low cost driver in a complex build of modest size.

is the target the skilled woodworker with no money (the amish, lol)?

i'm honestly not understanding what frontier this build is hitting on.

bfm, sadly, i agree with you about 95% on the patent matter.