Collaborative Tapped horn project

'Splitting hairs'? How? Medite [Medex] doesn't get its different properties [stiffer, more dense, moisture resistance] without consequence.

That said, I haven't cut any form of particleboard other than cabinet grade HDF since the late '70s IIRC, so I guess they could have come up with some formulation to improve its work hardness.

GM
 
Hi Y'all,

For me the main reason for using plywood over MDF/OSB/Particle Board is the weight (I'm talking about a test box).

As to the front loaded horn, you can build one with the driver exposed; you can also build it with the exposed driver offset to the side of the horn. These can all be easily simulated in Hornresp.

Regards,
 
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..A front loaded horn, now that sounds interesting too, although I'd have no idea how to model it..

Hi,

Prepare for this type of acoustic sum if you plan to copy the Trio12 FLH. 😱

b🙂
 

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Hi,

Prepare for this type of acoustic sum if you plan to copy the Trio12 FLH. 😱

b
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I usually just sit back and watch this thread.

But on what grounds is the eek there?

I have posted the outside ground plane measurements. They really even up when measured inside. The sub is a minimum of 94db/watt real world in the middle of the room efficient.

And quite a few have been built to raving reviews.

Where's the eek?

Measure any sub in a room and see if you end up with anything even remotely as flat as what has been posted.

Sims are one thing, a ground plane measurement outside is another. But the sound we actually hear in our listening rooms is anything but flat. I have measured and posted in room response graphs that are flatter than that. The benefits of horn loading and very controlled directivity.

Preaching to choir to be sure bjorno. This is nothing you do not already know.

But please be fair.

You post a whole bunch of well designed Tappered Quarter Wavelength designs.

I'm guessing you have build just a few (😉) over the many years I have known you. They have their own attendant sonic anomalies. I have built and listened to them as well as demonstrated them at an audio show. Comparing them head to head with front loaded horns there is a definite difference. As a musician I prefer the clean sound of the front loaded horn. It simply has less distortion and cleaner more accurate attack. It sounds closer to real life. People who listen primarily to pop and processed music prefer the sound of a resonant system. It sounds closer to a vented box type of sound. In particular one where the driver and vent are not properly matched in size.
 
Hey guys.
I'm "back", the attempts previously posted here have been scrapped mostly because I don't have a lot of money for this (love being a student).
Well, since my friends have grown extremely sceptical of a horn sub sounding good, or even reproducing any sound, I sort of have to prove it to them that TH's (hopfully) do work.
I have my eyes on a driver, the tangband w8-740e. It's cheap (50e) over here and it has a nice +-12mm xmax 🙂
I've recently moved into a small flat, and the main criteria for this build are:
Cheap and good sounding, while being small and going low and efficient 🙄
I've chosen to go for a 30hzish tuning, with a sort of low efficiency (2pi 2.83V ~93db) resulting in a ~65l box, absolutely acceptable!
Here's the sims, if you have something you would change, fire away!

An externally hosted image should be here but it was not working when we last tested it.


Now I'm reading about a plan bjorno simmed for a small tapped pipe thingy 🙂 http://www.diyaudio.com/forums/subw...mendation-please-tb-w8-740-a.html#post2229283
It looks really cool (I would need more amp power, expensive) but I don't think it's physically possible to fit a driver that needs 20cm x 15cm in a cross section of "even" 100cm^2.. I can't get my head round how it would be possible, unless the last portion of the tube was made large enough for the driver? (simmed it and made the bottom end drop too much)

So if you have recommendations or anything of the sort I'll gladly listen to them, and hopefully I'll have some pictures of a finished sub up here at some point 🙂
 
..Now I'm reading about a plan bjorno simmed for a small tapped pipe thingy 🙂 http://www.diyaudio.com/forums/subw...mendation-please-tb-w8-740-a.html#post2229283
It looks really cool (I would need more amp power, expensive) but I don't think it's physically possible to fit a driver that needs 20cm x 15cm in a cross section of "even" 100cm^2.. I can't get my head round how it would be possible, unless the last portion of the tube was made large enough for the driver? (simmed it and made the bottom end drop too much)...

Hi,

IMO it's possible to fold my suggestion..I reworked the simlation by adding a chamber...

b🙂
 

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Can I presume the green response is after filtering?
What filters are used?
What is the red response?

27Hz from a 23litre box !!!!!

Four of these little boxes spread around the room and each fed from a 150W amplifier gets one up to 109dB @ 27Hz. Mighty impressive.

edit,
now I am wondering with 4boxes being fed a total of 600W, is the SPL really only 109dB, or does the extra cone area boost the SPL in the low frequencies?
 
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Can I presume the green response is after filtering?
What filters are used?
What is the red response?

27Hz from a 23litre box !!!!!

Four of these little boxes spread around the room and each fed from a 150W amplifier gets one up to 109dB @ 27Hz. Mighty impressive.

edit,
now I am wondering with 4boxes being fed a total of 600W, is the SPL really only 109dB, or does the extra cone area boost the SPL in the low frequencies?

Hi Andrew,

To answer:

1. The filters in use are 30Hz High-Pass Butterworth 4:th order and a 4:th order LR Low-Pass filter.

2. The red response is of the Filters in use.

3. 27Hz from a 23litre box is IMO only safe at an sustained input power of ~ 50 W(<= 6000 Pascals)... ~ Passband level of 116 dB/0.5Pi or ~ 104 dB /2Pi.

The CSA is only ~~ 3.6-3.7 x ~ 21 cm and must be multifolded to lower the off-band peaks as there is no place for adding damping material.

Youre right, 4 boxes in 2Pi are at ~~ 110 dB but in 0.5Pi= close to 122dB,more in line with the eventual use.

b🙂

PS: Warning: My spell-checker is out of order..🙁