EAW 18" driver specs

[Graydon]

EAW 18" driver specs

Hi guys,

I am building some _very_ large permanent installation subs. Does anyone have specs for the EAW L18 851 18" drivers?

Thanks,

 

[BillFitzmaurice]

I don't have specs off hand, but since EAW is a pro-sound company make well sure before you start that they are appropriate; the average pro-sound sub has an f3 a full octave higher than the average HT sub, irrespective of driver size.

 

[Graydon]

Thanks, I'll check into that. I have an email into EAW right now but haven't heard back from them just yet.

 

[BillFitzmaurice]

Check the RCF website, that's where EAW used to source most of their drivers.

 

[OMNIFEX]

fs = 38.7

Qes = 0.38

Qms = 6.00

Qts = 0.35

Vas = 200 liters

Re = 5.7

Xmax = 5.1 mm


Have Fun!

 

[BillFitzmaurice]

As I suspected these specs indicate an f3 of 45 Hz, which is quite acceptable for pro-sound, not worth much for HT. At 25 Hz I can blow this puppy away with an eight in a 3.3 cu ft folded horn.

 

[Zero Cool]

fs = 38.7

Qes = 0.38

Qms = 6.00

Qts = 0.35

Vas = 200 liters

Re = 5.7

Xmax = 5.1 mm


Have Fun!

Check out that Xmax, thats less then 1/4" of cone travel! these babies just dont move a lot of air compared to a home or car type woofer!

Zero

 

[Graydon]

Thanks guys.
I'll post a new thread to ask you what you might recommend for my enclosures. I'll post pics of what I have so far too. Later...

 

[Zero Cool]

Just for fun comparison, here are the specs from the Aura sound NRT18-8:

FS: 25Hz
Qes: 0.28
Qms = 4.4
Qts = 0.26
Vas = 475 liters
Re = 5.6 ohms


Xmax = 18 mm

That right Kiddies! 18MM Linear max excursion!!!! Now thats a sub!!!! For us in the USA lets put that into perspective, thats 3/4" of one way travel!


Zero

 

[OMNIFEX]

Why would anyone try to reproduce 25Hz with the RCF?

You want a sub, you use a McCauley 6174 (fs = 15Hz)

 

[Zero Cool]

And if you really want some fun, get a pair of these!!!

http://www.servodrive.com/basstech7.html

THE WORLD'S MOST POWERFUL SUBWOOFER

Amplifier Capacity
Continuous Power (per modified AES procedure, 24 hrs.) 400 Watts RMS

Musical Peak Power Capacity (<15 seconds) 800 Watts RMS

Power Compression
Full power after 15 minutes <1.5dB
2x full power after 15 seconds <2dB

Nominal Impedance 4 Ohms

Sensitivity
Spectrum (28-125Hz) (1/2 space, groundplane)
2 units - 107.5dB (1W, 1m)
4 units - 110.0dB (1W, 1m)

Sound Pressure Level
Full Rated Power (28-125Hz) (1/2 space, groundplane)
2 units - 136dB
4 units - 142dB
(Peak SPL: +3dB)

Low Frequency Corner (-3dB)
2 units - 30Hz
4 units - 28Hz

Distortion, Full Rated Power
Second Harmonic, 28-125Hz <1% typical
Third Harmonic, 28-125Hz <1% typical


Radiators

2-15" pistons

Maximum Excursion/Driver

>1" peak-to-peak linear excursion +3dB excursion headroom at 400 watts/30 Hz

Crossover Slope
Recommended
>18dB per Octave @ <125Hz

Dimensions & Weight

45" x 45" x 22.5" - 230 lbs.
Enclosure Construction

•14-ply Baltic Birch with extensive bracing
•27 Hz Hyperbolic Flare T=.55
•Horn Length 10.6 feet

Horn Throat Compression Ration
3.4 to 1


We put 4 of these into a stretch limo van for a joke at a car stereo competition and literally ripped the sheet metal on the roof, broke the tops of the doors, broke ALL the glass, and in general damaged the structural integrity of the body so badly the van had to be towed home!

Zero (likes BIG subs!)

 

[OMNIFEX]

The only problem with them is they handle only 400 watts.

If you are looking at Servo's you more than likely have a huge
bass amp on the sidelines.

Well, at least I do 😀

Give me the Bassmaxx B Zero's, McCauley loaded, and, let
the party begin

 

[Zero Cool]

Yeah the Servos are only good down very low, as subs really, i never run them up past 60Hz...

I know there are others out there. but then thing that makes the servo's so good is little power compression and little distortion!!


Zero

 

[mike.e]

This is off topic ,but to continue in this trend-

Give me the Bassmaxx B Zero's, McCauley loaded, and, let

I like loudspeakers -not musical instruments that add distortions to the audio signal. -A scoop with only one side of the cone horn loaded will result in assymetrical waveforms and harmonic distortion. Perhaps you listen to reggae,which is meant for scoop usage,but i dont 🙂

Wireless World march 1974
J Dinsdale ,M.A, M. Sc
"Mention has already been made of distortion resulting from the non linear expansion/compression characteristics of air. This effect is accentuated when a loudspeaker is horn-loaded on one side only, [ie scoop/bassmaxx] because the constant resistance characteristic of the throat acts only against excursions of the cone in the forward directio.when the cone moves back it is agaisnt a far lower load and hence the excursion will be larger.

'an alternative solution favoured by many designers is to load the rear of the loudspeaker by a sealed compression chamber,the effect of which is to provide a loading similar to the horn.The compression chamber thus reduces the effects of nonlinearity due to uneven loading on each side of the loudspeaker diaphragm, and also presents a better resisitve load to the diaphgram because a closed chamber on the opposite side of the diaphagm to the horn itself acts as an inductive reactance which tends to balance the capacitive reactance presented by the mass reactance of the throat impedence at low frequencies."

 

[mike.e]

Just for fun comparison, here are the specs from the Aura sound NRT18-8:

That right Kiddies! 18MM Linear max excursion!!!! Now thats a sub!!!! For us in the USA lets put that into perspective, thats 3/4" of one way travel!

Zero

But how much does it cost? Could i buy four 18"s of 1/4 the price and get the same Vd and more Sensitivity

 

[OMNIFEX]

This is off topic ,but to continue in this trend-


I like loudspeakers -not musical instruments that add distortions to the audio signal. -A scoop with only one side of the cone horn loaded will result in assymetrical waveforms and harmonic distortion. Perhaps you listen to reggae,which is meant for scoop usage,but i dont 🙂

Hold on there kimosabee 😀

Have you Actually Heard A Bassmaxx B Zero, loaded with
a McCauley 6174?

Do you know side to side comparison Bassmaxx -vs- Lab Sub,
that the similarites are so close you can't decide which one to
choose?

Thanks for the literature, but, it doesn't mean anything.

Thats just one mans technical view of the matter. Maybe he should listen to Bassmaxx B Zero loaded with a McCauley 6174, and, let his ears decide.



Rock On!!!!

 

[OMNIFEX]

But how much does it cost? Could i buy four 18"s of 1/4 the price and get the same Vd and more Sensitivity

Ha Ha!!!!!

Dude, if you are so intrested in this driver, you might as well,
listen to Bassmaxxx. They use that driver in their boxes as well. 😀



Rock On !

 

[Zero Cool]

We seem to have traveled far of the path here!

I was only poking some fun! I like RCF drivers, but they are very stiff! and just dont work very wee as true subwoofers!

There are LOTS of drivers out there there are great! have better specs, cost more/less, etc etc.

When i saw the Xmax spec posted i thought to my self "that cant be right, could it?" 5mm thats it???? so for fun i made the post about the Aura's, YES there darned expensive!!! and im sure there are other solutions as well.

Consequently the McCauley Drivers was what my 2nd choice was going to be to post! I like th MC's, i have used them on every installation that the budget would allow me to put them into!!!

Sorry I didnt mean to fire up a yours is bigger then mine post!

Zero

 

[OMNIFEX]

Zero Cool, we answered the original poster's question, why not have some fun talking high excursion woofers


You are like Zero Cool Dude 😀


No argument on my part, just pure fun. Learning can be fun!!

Right???



Rock On !

 

[Graydon]

Hey Guys,

Thanks for the comments. They have all been interesting and informative. I am not spending $800 each on drivers... yet. I've been checking out those McCauleys though. They _are_ nice.