Collaborative Tapped horn project

[otto88]

Thanks muchly GM!

(due to new & still unresolved home network problems, still unable to download/ install Hornresp)

Not sure I understand all of your posts correctly, but as it reads to me (in this 40! degree C local heat ~105! F, brain semi meltdown):
you simmed the Focal in Hornresp (the 1st screen dump) and it's clearly a bit too ripply.

You then simmed the PHL "using ML's math", and in Hornresp(?)
If I understand you correctly -
With series R compensation, the 320 Hz TH was smoothed; but in the 615 Hz TH, efficiency was lowered without any smoothing; and a 615 Hz PHL TH was the better damped = smoother, and much smaller than the 320 Hz TH.

TH 101: what is the physical horn difference between THs of different upper cutoffs, ie 615 Hz and 320 Hz - eg a different length/ flare rate??

The best option looks like a PHL in 615 Hz without R compensation - do you have a screen dump of it's FR, and the assumed physical dims (line length, tap point, mouth, etc)?

> How do you build a tapped horn without a fold

My bad English. Instead of saying "initially without a bend, and one added later", I should have said "initially with 'box' corners, and smoothing of bends done later"

Cheers

[otto88]

GM,

Rather than max BW or bottom end (I'll use a sub below) the aim is minimal distortion and colorations

> You can fold a FLH too.

Very good point - over the same broadly midbass 90 - 360 Hz range (with the PHL) how would a folded FLH be likely to compare with a TH??

I also need to have construction KISS, which is what attracted me to THs . .

Thank you

[GM]

Greets!

You're welcome!

Oooh! I've worked/suffered through such heat and it can literally be a killer, so keep yourself well hydrated, protect skin, etc..

Correct. Apparently, the wider BW's smaller throat to a smaller mouth damped it enough to negate the electrically added damping alignment.

On a TH, 'Fh' sets the driver's location along its length.

OK, a good plan considering we're not sure if we want the extra HF output a smooth bend implies. I know in simple pipe horns we keep the bends 'crude' and sometimes even add damping in the bend(s) to tone down its HF output and if I ever get to build any TH's, I'll be experimenting with damping to smooth less than optimum alignments.

GM

[judtoff]

Just thought I'd add an experience of mine.

I was testing out my LM3875 chipamps bridged into my tapped horn. I am very impressed by the sheer efficiency of tapped horns. My amp has 25V rails, and was putting out 20Vrms into a 4R load. So only about 100 watts or so. It was pretty impressive. It would be very easy to make your own DIY active subwoofer, right down to the amp and everything. The thing I like the most about my TH is that it can keep up with the full range speakers, with the same power.

[Brett]

Originally posted by otto88
The best option looks like a PHL in 615 Hz without R compensation

Why? Even if you want a lowest useablr F of an octave below that, a simple conical will likely have less artifacts from the horn. See Adrian Mack's A6 conical for example.

[Killjoy]

Hello GM:

I really appreaciated you taking the time to run some sims on my sub. I am still trying to get my head around the s1 - s4 thing. I read Buzzy's post and the replies and I think I got it. Once I figure out how to post an image I will send you what I think it looks like. Thanks agiain.

[otto88]

> On a TH, 'Fh' sets the driver's location along its length.

Fh is a setting within hornresp? (I should be able to get hornresp going on the weekend)

Posted by Brett
Even if you want a lowest useable F of an octave below that, a simple conical will likely have less artifacts from the horn. See Adrian Mack's A6 conical for example.

I wanted something that won’t take too long to build. That’s what attracted me to the TH. I’d expect a straight conical to be cleaner, but by how much; and a TH vs a folded FLH . .

Originally posted by otto88
The best option looks like a PHL in 615 Hz without R compensation

Posted by Brett
Why?

I wasn’t sure that I understood GM correctly. I thought that amongst the TH options canvassed, that was what *he was saying - am I wrong?

Thanks

[Brett]

Originally posted by otto88
Posted by Brett
Even if you want a lowest useable F of an octave below that, a simple conical will likely have less artifacts from the horn. See Adrian Mack's A6 conical for example.

I wanted something that won’t take too long to build. That’s what attracted me to the TH. I’d expect a straight conical to be cleaner, but by how much; and a TH vs a folded FLH . .

All the TH sims have a ton of artifacts up high, as you would expect from something summing the front an rear waves of the same driver's radiation within an enclosure. Good at long wavelengths.

But let's be realistic; how is a conical flare any more difficult to make than a TH?

[GM]

Originally posted by otto88

.......the aim is minimal distortion and colorations

........over the same broadly midbass 90 - 360 Hz range (with the PHL) how would a folded FLH be likely to compare with a TH??

Thank you

Greets, part deux!

You're welcome!

Probably no comparison. As I noted at the beginning, I wouldn't use a TH in this BW based on what little I currently know about them. I'd have to be desperate for a compact system to even consider it and have plenty of digital EQ available to tame it if I couldn't do it with internal damping without a major loss of efficiency.

That said, an 'ideal' T/S max flat BP alignment yields the best performance AFAIK, but the driver has to have the 'right' specs for the desired gain BW and it will be huge since the only thing controlling its performance is the sheer mass of air 'trapped' in the horn.

For example, changing the Focal's Fs, Qes to an 'ideal' driver for a 56.56 - 320 Hz alignment with loading to 80 Hz requires 365.625 L net according to Hornresp, but you get what you 'pay' for:

GM

[GM]

You can 'cheat' by cutting it off at 80 Hz and it's only 138.069 L: