Collaborative Tapped horn project

[JSS]

I was browsing Audio Asylum and found a link to this very interesting thread. After reading it for a few days I'd say I am ready to inhale some sawdust. I have the driver below for a few months now doing nothing, I thought I'd put it to use.

Do you think this would work in William's 30Hz horn?

Eminence Magnum 12HO (8ohm, 600W)
Fs 43Hz
Qts 0.29
BL 19.4
Xmax 4.8mm
Xmech 22.35mm
Accordian surround

Thanks,
Jeff

 

[JSS]

This is what I get, quarter space. I tried tweaking the length and area, does not seem to make much difference. Any ideas to make it flatter? Or is this good enough?

 

[Samuel Jayaraj]

Tapped Horn with Eminence Drivers??

I have 4 huge horns with EV's 15" EVX150A drivers.

I also have 4 Tuba 24s with Eminence's 10" HL10s. To give Bill Fitzmaurice credit, I should say that the Tuba 24s when splayed at right angles (with the mouths firing into each other at 90 degrees) sound phenomenal. Having built Bill's mid-high cabs called DR300, I can vouch for the performance of his designs.

However, I have some ply cut for both the Tuba 36 and Lab subs but am reluctant to assemble the box for the sheer reason of size and weight.

I do have a pair of Lab12 drivers for over a year now.

Question is, Is there any Eminence driver that can be successfully used in a Tapped Horn design for outdoor use?

Thanks,

 

[djk]

"just step the areas to approximate the desired expansion."

36"x36"x24" (external), 96" air path (35hz).

Angled board has modified K-slot for mounting driver, and clearance for magnet structure (Eminence 3015LF).

 

[GM]

Or is this good enough?

I guess that's up to you. I got this on the first pass, but it's ~700 L.......

GM

 

[GM]

Hmm, what's '0.0 x Pi' equate to? Ground plane outdoors? If so, the one I just posted looks pretty good to me:

GM

 

[Samuel Jayaraj]

Tapped Horn with Eminence Drivers??

Thanks DJK for that folded design or is it actually a Tapped Horn?

What is posted is the same outer dimensions as that of the Tuba 36. However, will I get more output SPL than the Tubas?

It is said that with a pair of Labs or Tuba36s, when driven to maximum power, the sound can be heard at a distance of nearly 2kms!!!

I am looking for something which has more efficiency and goes flatter in the lower frequencies, say 30 to 35 Hz upto about 90 to 100 Hz. All of the Tubas have higher efficiency around 100 Hz but tend to drop off for lower frequencies. The problem with the Labs or Wayne Parhams 12Pi (modified Labs) is that atleast 4 boxes or ideally 6 need to be used together, ie., per side or in the centre. While this may be possible for big venues and live performances, this arrangement may not always be possible for outdoor dance programs - the stage and venue is generally smaller.

So to repeat myself, DJK would this design go louder and lower than the Tuba 36s?

Does anybody have any more inputs on Tapped Horns using Eminence drivers?

Thanks again,

 

[SpeakerBob]

Could I ask what sort of driver specs I should look for if I wanted to do a tapped horn that is flat from 10Hz - 30Hz ?

I've got a feeling I'll be glueing some weight onto a lab12 / car audio type driver ?

Cheers,
Rob.

 

[judtoff]

"just step the areas to approximate the desired expansion."

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

36"x36"x24" (external), 96" air path (35hz).

Angled board has modified K-slot for mounting driver, and clearance for magnet structure (Eminence 3015LF).

Is their any disadvantage to stepped horns?

 

[JSS]

Post #726

Thank you GM. I believe 0xPi is a horn that goes forever,infinite, better than corner loaded? That response looks perfect, can I please get a screen shot of your input params?

Thanks

 

[GM]

Could I ask what sort of driver specs I should look for if I wanted to do a tapped horn that is flat from 10Hz - 30Hz ?

Greets!

FWIW, I calc a ~17.32 Hz Fs/~0.408 Qes as 'ballpark' figures for a simple end loaded conical pipe horn like the two I recently posted, but assuming a LABhorn driver's Vas, then at ~107 ft^3 I doubt you'll be hauling it out of the workshop in one piece. Even then it's too small to be flatter than ~ +/- 3 dB. Since the DTS 20 is about the same down to < 20 Hz in a drastically smaller bulk though, so apparently it's no simple conical pipe horn as I understand them, making my calcs moot for an optimum alignment.

GM

 

[GM]

Thank you GM. I believe 0xPi is a horn that goes forever,infinite, better than corner loaded? That response looks perfect, can I please get a screen shot of your input params?

Greets!

You're welcome!

Thanks, I'd been up for ~24 hrs when I posted that, so between having a 'senior moment' combined with sleep deprivation, I couldn't 'wrap' my mind around the obvious that zero pi = infinite.

Yeah, ~'infinitely' better.

It's not perfect since in theory it should be smoother over a wider BW, but plenty 'good enough' IMO for HIFI/HT apps once EQ'd ~flat in-room.

GM

 

[Fast1one]

Such a wealth of information in this thread, i downloaded the program mentioned on Cowan's site and began playing with a driver I have laying around...


*Power Handling: 80 watts RMS/120 watts max
*Le: 1.2 mH
*Impedance: 8 ohms per coil
*Re: 3.00 ohms
*Fs: 28 Hz
*SPL: 89.0 dB 2.83V/1m
*Vas: 39.1 Liters
*Qms: 3.40
*Qes: .47
*Qts: .41
*Xmax: 6 mm

Just for fun I put it in the 30 hz horn, but I don't know where to go from there. I'm guessing I need to tune lower because of the FS of the driver, any suggestions for this driver? It will be crossed over fairly low (50hz ish) and used primarily for movies, turned off for music.

 

[SpeakerBob]

Greets!

FWIW, I calc a ~17.32 Hz Fs/~0.408 Qes as 'ballpark' figures for a simple end loaded conical pipe horn like the two I recently posted, but assuming a LABhorn driver's Vas, then at ~107 ft^3 I doubt you'll be hauling it out of the workshop in one piece. Even then it's too small to be flatter than ~ +/- 3 dB. Since the DTS 20 is about the same down to < 20 Hz in a drastically smaller bulk though, so apparently it's no simple conical pipe horn as I understand them, making my calcs moot for an optimum alignment.

GM

Thanks GM, I'm going to have a browse through some car audio drivers to see if there are any that fit the bill.

Rob.

 

[djk]

Hope this is clearer as to my intent:

 

[JSS]

It's not perfect since in theory it should be smoother over a wider BW, but plenty 'good enough' IMO for HIFI/HT apps once EQ'd ~flat in-room.

GM

It's long but Wow, I did not think it would be possible to get flat to 18Hz. There is a 7db rise from 50hz, I have to cross at 80, do you recommend an 80Hz XO on this horn? Or is it too much to eq?

Thanks

 

[GM]

Thanks GM, I'm going to have a browse through some car audio drivers to see if there are any that fit the bill.

Rob.

Greets!

You're welcome! I doubt there will be any in the car audio crowd, this is more a HT spec sub driver, though of course if you can find the right specs to mass load to these 'ideal' specs.......

GM

 

[SpeakerBob]

Your post here is saved as inspiration, so I guess I'm looking at ways to use the tapped horns smaller footprint with the benefits of the 'custom' driver.

I've been fairly busy with real life stuff so not had time to mess with building much recently, but plan to get back into building some stuff next summer. Am focusing on something small enough to squeeze into my room to fill in beneath my labsubs.

Cheers,
Rob.

 

[GM]

There is a 7db rise from 50hz, I have to cross at 80, do you recommend an 80Hz XO on this horn? Or is it too much to eq?

Thanks

With a usable XO BW out to ~300 Hz, none of this is a problem with digital EQ and XOs and there's room gain to consider, so just dial it in in-room as required, just make sure you can adjust TD/phase too for best results.

GM

 

[zobsky]

Hope this is clearer as to my intent:

I had a similar folding idea a few months ago, ... never bothered to follow up on it. Ignore the dimensions.

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