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160db in the low 20hz range


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My home theater subwoofer, a folded horn (Tuba HT) with 10.8 volts or 29 watts of power can do a calibrated 130+ DB's in a 10,000 sq foot room @20hz.

110db 1 watt/1 meter sensitivity. You do the math with 500 watts :)

Below 20hz down to low teens (13hz) it will do 125dbs all day long, again in a room that is 10,000 sq feet.

Put it into a van/truck, and who knows what it does. I gotta think cabin gain would boost it up 10 - 15dbs

Keep in mind the Radio Shack Digital SPL meter reading at frequencies below 25hz are -8db below actual calibrated mics.

To compare, the 14 cu foot enclosure to the left of it in the video which is a traditional EBS/LLT ported alignment tuned to 14hz with a Mach5Audio 18" IXLi 1/4 as loud. Horns are a force to be recon with. They'll eat up sealed/ported for lunch all day long at the expense of size.

Distortion measurement:

Music:

Movie:

Inside:

IMG_5875.jpg

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take that rat shack meter and throw it out hte window.

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take that rat shack meter and throw it out hte window.

Why? Given the correction tables, it's been proven 100x over to be quite accurate. Unless you know of another solution costing < $50? Maybe we should all just fork out $650 for a TermLab?

http://forum.audiogo...86&openflup&1

http://www.danmarx.o...on/rsmeter.html

http://www.gti.net/w...55/33-2055.html

http://www.etfacoust...AnalogueSPL.zip

http://www.audioc.co...stcd/testcd.htm

http://www.hometheat...ion-values.html

http://www.audioxpre...ia/koya2811.pdf

http://www.svsound.c...faqs-rscomp.cfm

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this thread was previously discussed, iirc it would cost around $100,000.

so....

good luck.

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lots of time spent in box design youd have to build a box that most likely would peak in that area. so tuning your box really stupid low.

like probly 15 hz.

have ALOT of Port.

and alot of power..with more power and probably some more.

oh did i mention power.

and after all that you wouldnt be able to hear it. because humans cant hear below 20 sumthing hz

oh and dont forget the 10s of thousands of dollars youll probly spend

Low end of the human hearing range is supposed to be ~20Hz but some people can't hear that low some can hear lower

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I would start with 4 400a alts, 15-20 D3100s and about 6 9k amps. Then I would look into maybe 12 18s. Oh yeah and someone crazy and smart enough to build it.

Here are just some guesstimates on prices:

Alts- $2500

Batteries- $7000 $10500

Amps- $12000

Subs- $7500

Misc supplies and Materials- $6000

Labor- $25000+

Total- $63500+

I think that should about do it.

EDIT: Thought about it and 20 D3100s just wouldnt cut it for 54000w. I think 30 should do the trick.

You may need more batts actually. And more money.

Thing is, youd have to choose a suitable vehicle, and you cant just pick a random number of woofers like 12 18s.

You have to design around the vehicle being used. The cabin airspace is basically like a chamber of the enclosure, and cone area and displacement would have to be matched to that. So there is a chance 8 18s would get louder or perhaps 16 15s depending on the vehicle.

Then there is the question as to whether or not the vehicle would hold up to the sympathetic vibration.

The best thing to do would be to build a large extreme vehicle tuned to that range. So you are looking at even more money in the build and money to support hauling and storing it.

I'd estimate around $150,000

But ya know, there was a vehicle that once did a 170 at 7hz.

It was Richard Clark's bread truck with the custom 60" woofer he built run off an electric motor system. I believe he had well over $100,000 in it and he only played it 3 or 4 times before it was trashed.

Ed Lester

ShowtimeSPL Host

Showtime Electronics Video Marketing

My old Build Log
http://www.stevemead...08/#entry511451

http://www.youtube.com/showtimespl



TeamDeadlyHertz-HHREd.png


5 time dB Drag Finalist
Last ride 2007 HHR, current dB 153.5 and bass race 149.4 dB. 153.0 dB on music

New Ride, 2008 HHR SS. Build under way.
Loudest score ever = 171dB
2009 dB Drag Racing, North American Points Champion

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My home theater subwoofer, a folded horn (Tuba HT) with 10.8 volts or 29 watts of power can do a calibrated 130+ DB's in a 10,000 sq foot room @20hz.

110db 1 watt/1 meter sensitivity. You do the math with 500 watts :)

Below 20hz down to low teens (13hz) it will do 125dbs all day long, again in a room that is 10,000 sq feet.

Put it into a van/truck, and who knows what it does. I gotta think cabin gain would boost it up 10 - 15dbs

Keep in mind the Radio Shack Digital SPL meter reading at frequencies below 25hz are -8db below actual calibrated mics.

To compare, the 14 cu foot enclosure to the left of it in the video which is a traditional EBS/LLT ported alignment tuned to 14hz with a Mach5Audio 18" IXLi 1/4 as loud. Horns are a force to be recon with. They'll eat up sealed/ported for lunch all day long at the expense of size.

Distortion measurement:

Music:

Movie:

Inside:

IMG_5875.jpg

Are you trying to estimate SPL based off of the sensitivity rating and a weighted measurement from a non accurate mic type meter that is easily thrown off calibration?

If so, throw all those numbers out the window.

Ed Lester

ShowtimeSPL Host

Showtime Electronics Video Marketing

My old Build Log
http://www.stevemead...08/#entry511451

http://www.youtube.com/showtimespl



TeamDeadlyHertz-HHREd.png


5 time dB Drag Finalist
Last ride 2007 HHR, current dB 153.5 and bass race 149.4 dB. 153.0 dB on music

New Ride, 2008 HHR SS. Build under way.
Loudest score ever = 171dB
2009 dB Drag Racing, North American Points Champion

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Are you trying to estimate SPL based off of the sensitivity rating and a weighted measurement from a non accurate mic type meter that is easily thrown off calibration?

If so, throw all those numbers out the window.

Nope. The designer, Bill Fitzmaurice speced the 110DB sensitivity for this folded horn. Which is directly inline with other folded/tapped horn designs out there.

Have you guys seen Tom Danley's TH-221 and TH-812 Tapped Horns? All of these measurements are measured in half-space. Outside basically on single plain (ground) :) If they are capable of doing 150's outside, imagine what they can do in an enclosed cabin with transfer function.

http://www.danleysou...pec%20sheet.pdf

http://www.danleysou...pec%20sheet.pdf

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