Modeling the MTX 22" Jackhammer for fun!

Hello all,

I decided to model the MTX 22" jackhammer subwoofer just to see how it preforms, for those that are unfamiliar with it, it is basically the biggest car sub ever made, it is about 3 feet tall, weights 200kg has 3 inches of mech Xmax and can handle 6,000 watt RMS, and 12,000 peak!

I chose a 30 cubic foot box and a 13Hz tune, a real SLLT! input power 6.5Kw, high pass at 10Hz, to keep port speed in check, the port diameter has to be 16":eek:, thats almost big enough to crawl into!

There is the simulated output:

10Hz-113db.
13Hz-125db!!
20Hz-120db.

And flat at about 122db from there on, considering the sub costs around 5,000 dollars, you could have 4 Mal-X 18"s for the same price which would almost equal the MTX at 13Hz and kill it by about 6db from 20Hz on.

So there you have it, if you have a spare 5K to spend on woofers you know what to get!:thumbsup:
 

Member 639844

Former Advertiser
for 5k, I would be looking at either the Maelstrom 21" woofers, or more likely the TC sounds LMS Ultra 18" driver. You could have 4 21's or 2 of the 18's, and still have plenty of change for a lovely amp.
 
Four 18"s would be pretty amazing, the LMS ultra is designed so well, its a shame you can't just use it free air, because it looks this a piece of art!

It's funny how no one on his site has gone for a Tapped horn design, i would build one if i had the skills, but i do not, for the price of a Dayton DVC 15", a couple sheets of ply/MDF and a 200-300 watt amp, you can get €1500+ performance.

You should put one on build list!:D
 

Member 639844

Former Advertiser
Ive looked at them, but I would need to understand the designing part really, which is one of those things I may get round to one day (I want to do speakers at some point when time and funds allow). The only issue I have with horns, is that Ive yet to ever hear one that I didnt feel had some colouration to its sound, which really puts me off, not to mention the sheer size of a good one using a high quality sub driver. I could go with a kit, but then whats the point in that :D
 

micb3rd

Novice Member
As I have said before T&S params are for small signal analsys and any guestimated DB levels from sofware is to be taken with a *very* large pinch of salt. Plus Winisd is akin to 1m values and most ground plain measurements are 2 meters so you can minus 3db of them straight away ;)

The Jackhammer is only impressive in sheer size and weight. I have seen and felt 2 of them. I have yet to hear one. There is one at Bassjunkies in Brum and that should be going in a customers car.

It has a 6 inch coil and from all the tests I have seen is very very inefficient, a decent pair of 18's would walk all over in output.

It is a show case woofer and not really pratical at all.
 

micb3rd

Novice Member
Ive looked at them, but I would need to understand the designing part really, which is one of those things I may get round to one day (I want to do speakers at some point when time and funds allow). The only issue I have with horns, is that Ive yet to ever hear one that I didnt feel had some colouration to its sound, which really puts me off, not to mention the sheer size of a good one using a high quality sub driver. I could go with a kit, but then whats the point in that :D
Tapped horns are very different kettle of fish to a regular horn.

Even regular folded horns can actually have less distortion to the ear than a ported or sealed enclosure as in some designs the driver sits deep inside the horn and the mouth filters any direct distortion artifacts from the cone.
 
The thing about the Jack Hammer is, its a publicity stunt. I had never heard of MTX, but when i saw that episode of "pimp my ride" i went straight to the website to check the spec!

The output from these things is very impressive, even if it is just sine waves for SPL contests.

I was watching an episode of Mythbusters this evening and they were using a car with Dual 22" MTX's to try and set off a rifle with a floating firing pin, anyway, they output nearly 160db!! in the car, thats something even with cabin gain!

What sub/subs do you use yourself micb3rd? planning a Horn build?
 

micb3rd

Novice Member
The thing about the Jack Hammer is, its a publicity stunt. I had never heard of MTX, but when i saw that episode of "pimp my ride" i went straight to the website to check the spec!

The output from these things is very impressive, even if it is just sine waves for SPL contests.

I was watching an episode of Mythbusters this evening and they were using a car with Dual 22" MTX's to try and set off a rifle with a floating firing pin, anyway, they output nearly 160db!! in the car, thats something even with cabin gain!

What sub/subs do you use yourself micb3rd? planning a Horn build?
The Jackhammer is not even that good for sine wave SPL compertitions it is too inefficient. No one has any SPL records from using Jackhammers.

I have been involved in the majority of the SPL formats over the last 10 years in the UK. These range both from extreme high tuned single note wonders 160db plus to the loudest bass systems which can play music (over 152db at 20hz).

I sold my audio car last year. I was using Fi Audio SSD 12's. I still have all the equipment The SSD's would be fantastic in home. When I upgrade my home set-up later in the year I'll have to have a play with them.

I currently run in home 2 x RE Audio SR 10 inch subwoofers in a 25hz ported enclosure.

I am tempted to build a single or a pair of Tapped horns but untill I do some room strenthening there is little point in going much louder than what I currently have as I get wall complaints at higher levels (105db plus).
 
Those RE SR 10"s look nice with good Xmax/power handling, an efficiency of 85.3db @ 1 watt at 1m ain't that good thought, compared to the mighty Jack Hammer:laugh:.

Why would you need to reinforce your room, would you worry about the tapped horns cracking the plasterboard? what one would you go for a tuba HT or maybe even the DTS-10! or design one yourself?
 

swiftpete

Distinguished Member
I can't believe this thing weighs 160kg. Blimey, it would take 2 strong men just to lift it. Putting one of these in your car would slow it down.
 
In pimp my ride, they used a forklift to mount it in a custom built steel frame. can you imagine the damage it would do in a crash if unsecured!:eek: not too mention how it would crush your fingers to a pulp if it slipped.
 

micb3rd

Novice Member
Those RE SR 10"s look nice with good Xmax/power handling, an efficiency of 85.3db @ 1 watt at 1m ain't that good thought, compared to the mighty Jack Hammer:laugh:.

Why would you need to reinforce your room, would you worry about the tapped horns cracking the plasterboard? what one would you go for a tuba HT or maybe even the DTS-10! or design one yourself?
Yeah, my plasterboard creaks like crazy, if I went for a tuba or an upgraded DTS10 i'd get bad noises.

Ha Ha that is a sensitivity value you quoted is not efficiency. It means absolutely nothing to subwoofers.

It can be measured in many different way and is not comparable. The box dominates the majority of the efficiency in a subwoofer ;)
 

Prize78

Well-known Member
The thing about the Jack Hammer is, its a publicity stunt. I had never heard of MTX, but when i saw that episode of "pimp my ride" i went straight to the website to check the spec!

The output from these things is very impressive, even if it is just sine waves for SPL contests.

I was watching an episode of Mythbusters this evening and they were using a car with Dual 22" MTX's to try and set off a rifle with a floating firing pin, anyway, they output nearly 160db!! in the car, thats something even with cabin gain!

What sub/subs do you use yourself micb3rd? planning a Horn build?
I'm sure i read somewhere that 165dB+ can stop your heart if you're not careful!!! :laugh:
 
What confuses me is the difference between db(A) and db(C), music seems to be measured in db(C), but db(A) is much "louder". 165 db(A) would definitely cause instant eardrum collapse and permanent hearing loss, it would be like standing beside a rocket launch, and there is normally a 10 mile "safety zone" around the launch area partly because of the SPL levels!

Also is there a db(A) to db(C) conversion, I would like to know that the listening levels i use are not damaging my hearing.
 

micb3rd

Novice Member
I'm sure i read somewhere that 165dB+ can stop your heart if you're not careful!!! :laugh:
No that is not true. As far as I have seen there have been nothing like that occur from .

It is a falacy which comes from the heart problems seen from an impact, when a object impacts hard on the chest 15-30 microseconds before the heart T-wave, there is a chance of causing ventricular fibrillation (electrical activity becomes disordered from the chambers pumping in a rapid unsyncronised way).

It is very unlikly to happen, but in sports like bassball/cricket a high power strike has a small possibility of it occuring.

I very much doubt in car bass has specific force to impact hard enough.


What confuses me is the difference between db(A) and db(C), music seems to be measured in db(C), but db(A) is much "louder". 165 db(A) would definitely cause instant eardrum collapse and permanent hearing loss, it would be like standing beside a rocket launch, and there is normally a 10 mile "safety zone" around the launch area partly because of the SPL levels!

Also is there a db(A) to db(C) conversion, I would like to know that the listening levels i use are not damaging my hearing.

Have a read of this.

What are Frequency Responses and A, C and Z Weighting Curves? - Castle Group Ltd

From personal experience bass can be listened to a fair bit louder than midrange or trebble before causing damage or pain.
 

The latest video from AVForums

Panasonic HZ2000 OLED TV Review: The best OLED for movie viewing in 2020
Top Bottom