A Tapped Horn Experiment

[bcpballer64]

You guys remind me of an ancient member forevrbumpn, who has been MIA for several years now, good read thus far, I'm always interested in the 'other' types of enclosures

[Triticum Agricolam]

Thank you Patrick but I think you have proven my point for me quite well. You were able to match the efficiency of my horn around 30 Hz, but you weren't able to match the frequency response at all. Above 45 Hz your ported box is 3 db or more below my horn so over the majority of its useful bandwidth that ported box is less than half as efficient.

[mrd6]

BOOM! This thread is awesome.

So, has anyone ever tried a really big horn in a vehicle? I have this bfm tuba HT sitting around my garage and I've always wondered how it would sound in the back of a Tahoe...different style horn but still super efficient

[Patrick Bateman]

Thank you Patrick but I think you have proven my point for me quite well. You were able to match the efficiency of my horn around 30 Hz, but you weren't able to match the frequency response at all. Above 45 Hz your ported box is 3 db or more below my horn so over the majority of its useful bandwidth that ported box is less than half as efficient.

If anyone wanted to invest a LOT more effort and quite a bit more money, you can raise the SPL by about 3dB using a front loaded horn instead of a tapped horn. Admittedly, this is really chasing that last 10% of performance, but if someone had the motivation, they could do it.

Lately I've noticed that Danley has largely been pushing their front loaded horns instead of their tapped horns, and I'm guessing that's because they can go a little bit louder.

Here's your tapped horn versus a front loaded horn of identical size. There are a few reasons the FLH gets louder:

1) In a vented box and a tapped horn, the woofer unloads below the tuninq frequency. In a sealed box or front loaded horn, it does not. Due to this, the low end rolloff is shallower, and that means you can tune the front loaded horn a little bit higher while still achieving the same F3

2) Due to the fact that the front loaded horn is tuned higher, the excursion is lower. Due to the excursion being lower, you can feed more power into the horn. The front loaded horn can take 1050 watts; the tapped horn can take 525 watts.

Another cool thing about FLHs is that the horn raises the impedance a bit. IE, if you have a 4ohm woofer in a vented box, it's a 4ohm woofer. A 4ohm woofer in a horn has it's impedance raised a bit, generally to about 5ohms. So that means you can potentially squeeze more power out of the amp.

If anyone wants to try making a FLH, I am using "Eazy Horn" to make these designs. You just plug in the F3 and it spits out the parameters for you.

[ShadeTreeMechanic]

Quick question: Are the walls of the horn at a constant taper, or does the angle get bigger as it gets farther from the driver? Also would a slot ported box benefit from having the port angled? Thanks!

[Triticum Agricolam]

Thanks for the front loaded horn example Patrick. Would you mind posting the HornResp input so I can pla around with it a bit?

I'll have to play with the EasyHorn spreadsheet when I get a chance too.

[baron_of_bass]

Great little debate you guys had. Good stuff fellas.

[Patrick Bateman]

Thanks for the front loaded horn example Patrick. Would you mind posting the HornResp input so I can pla around with it a bit?

I'll have to play with the EasyHorn spreadsheet when I get a chance too.

EazyHorn is great. Back when I used to design horns by hand, it would literally take 2-3 hours to do all the math. There's a TON of variables. With EazyHorn, you literally click one button and it generates everything for you. (You still have to cut and paste the numbers into HornResp; the beauty of EazyHorn is that it eliminates the guesswork.)

Here's the Front Loaded Horn for that E10:

ID=39.00

Ang=2.0 x Pi

Eg=64.81

Rg=0.00

Fta=2.40

S1=55.00

S2=55.00

Par=40.00

F12=0.00

S2=55.00

S3=250.00

Par=186.00

F23=0.00

S3=250.00

S4=500.00

Par=86.00

F34=0.00

S4=500.00

S5=682.00

Par=47.00

F45=0.00

Sd=333.30

Bl=16.32

Cms=1.88E-04

Rms=4.63

Mmd=118.73

Le=1.55

Re=3.80

OD=1

Vrc=8.60

Lrc=30.00

Ap1=0.00

Lp=0.00

Vtc=337.00

Atc=333.00

Pmax=100

Xmax=5.0

Path=0.0

Fr1=0.00

Fr2=0.00

Fr3=0.00

Fr4=0.00

Tal1=100

Tal2=100

Tal3=100

Tal4=100

Comment=Mobile T-5 - Sundown E-10v2 D2 - 3.5cf FLH

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FILTER

0 0.00 0.0 -11 0 0.00 0.0 0 0 0.00 0.0 0

0 0.00 0.0 0 0 0.00 0.0 0 0 0.00 0.0 0

19999 0 31 0

0.50.50.50.5

0.50.50.50.5

SSSS

1111

1111

2242

1111

112

000

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[bassfreak85]

how does it sound? got some cancellation issues?

It sounds great. Probably my favorite car audio sub thus far.

I'm sure I do have some cancellation issues with it in the vehicle. I just threw it in there for testing and haven't put any effort into dealing with cancellation or reflections.

Its finally nice to see someone who like this stuff as much has me and has some real knowledge. you used to compete in the early 2000s by chance? i used to travel all over and when i could afford to compete(was a teen up till i was in my early 20s). i used to live in the forums but everyone i used to know seem to be long gone.

[Kevin Miller]

Wow, amazing write up, over my head, but amazing. I like how with the finished product you can see the sub RIGHT there...

EDIT: when these get more common, or easier to get a design for one, the question/debate will come from people like me who own a full size SUV and I am looking at a small set up but have room to fit a box like that horn. With a proper design I can easily assemble it myself, and would save money buying only one (or perhaps 2) drivers instead of 2 or 3 or even 4 if the output was the same. Depends on IF* the output was comparable though, and if time meant nothing to me (box building aspect) or how easy it would be to acquire a design. so cost vs output vs time vs etc. etc. Kind of interesting. I love the science behind all aspects of car audio, I don't understand very much of it though, thinking about some aspects make my head dizzy, lol.

Same here, Very interesting. If you were to do one of these boxes in a SUV, How big would it need to be and what size sub or (subs) would you use to really get down ?