The Ariel as never seen before (incorporating Stig Erik Tangens Almighty subwoofers)

Having seen the enormous interest for the Ariel I thought it was time that I gave back some to the DIY community. I first read about the Ariel back in 1998 and I was rather impressed with the thought going into the whole project. Lynn Olsen’s philosophy also appealed to me regarding what Hifi is all about.
What I did not find appealing however was the bass performance of the Ariel, Lynn Olsen recognises this and offers some advice on improved bass performance using scan-speak speaker elements. On his website he also suggests the Almighty Subwoofer for people demanding the best. The Almighty uses a $600 15-inch JBL Pro element.
This really set me off thinking, which ultimately resulted in my “Petit Filou” Loudspeaker.
I like large speakers and I also like speakers that are visual statements, Jamo’s Oriel and Dynaudios Evidence are probably the most beautiful speakers out there. There are some obvious similarities between Dynaudio top of the line speaker and the Petit Filou, I don’t think you can regard it as a copy, visual inspiration would probably be more appropriate.
My Petit Filou speaker incorporates the Ariel ME2 and the Almighty subwoofer into one 200kg box. However for convenience reasons I have chosen to divide the box into segments. The problem is that the subwoofer requires a 220 litre box; this does get problematic when you chose to make the speaker no wider than 30 centimetres.
Also the width of the baffle in conjunction with a tweeter mounted in the centre, gave rise to some nasty diffraction phenomena. I hence chose to make the box in which the tweeter was mounted more organic in shape, thus minimizing diffraction problems.
If there is interest out there in this project, please let me know and I will write a more extensive column on the project.
The images included show the speaker without the JBL drivers mounted.

Active Filter
http://www.behringer.com/DCX2496/index.cfm?lang=ENG

The Almighty Subwoofer
http://member.newsguy.com/~stigerik/almighty/index.html

Ariel
http://www.nutshellhifi.com/Ariel.html

[IMGDEAD]http://www.ninfendo.com/speaker/speaker1.jpg[/IMGDEAD]

[IMGDEAD]http://www.ninfendo.com/speaker/speaker4.jpg[/IMGDEAD]

[IMGDEAD]http://www.ninfendo.com/speaker/speaker5.jpg[/IMGDEAD]

[IMGDEAD]http://www.ninfendo.com/speaker/speaker6.jpg[/IMGDEAD]
 
I was a little shocked to see that you live in the UK as initially it looked like a barmy Yank design to fill a ranch with music! :D (no offense to you or our time-delayed friends of course).

I find the subwoofer most intriguing, I've never tried designing one but employing a woofer with an Fs of 40Hz seemed like an odd choice for getting bass to 20Hz. It just goes to show how much I DON'T know about sub design. :)

The look you have gone for does indeed manage to make the speaker rather discreet and svelte like the Dynaudio behemoth. As I tried telling my mother as kid, she didn't need to get rid of my dad's gutsy B&W speakers just because they were big, black, ugly boxes. Black blends into any room and is actually quite unobtrusive IMHO. She went ahead and fell in love with the silver slimline 'BBC mike' B&W VM1 wall-mount speakers anyway, and the twin 10" woofer sealed-box maestros that were my audio education still reside in the loft back home.

Still, I digress. One thing I've got to ask you! About your Ariel baffles, what are the two small holes outside each woofer? They seem too small (and too sealed!) to be ports, yet too large to allow recessed fixings or grille mount holes etc. I'm curious. :xeye:

Ben
 
Vifa midrange etc...

Hi there!

Yes these small holes are the ports, the vifa midrange is tuned to 74Hz. The internal box volume for each element is 5.15 litre. The vents are 2.55 cm in diameter and 3.6 cm long.

Regarding the size of the speakers, with a love for music I don't really see to many obstacles for not having large loudspeaker. If I were a pianist, would I go for a small keyboard in my home, or would I chose a Steinway. The answer is of course obvious. However using 15-inch subs does require a large room and in all honesty my current bedroom is much too small.

The elements are currently flushmounted
 
Furthermore

Regarding the Baffles,

The ports for the Vifa midrange has not yet been varnished as the rest of the baffle, hence they look very bright on the first image, and they can appear to be sealed.

I am currently buying the Behringer DCX2496 crossovers. Does any people have any opinions on this crossover? Are there other brands I should check out?
The subs and the mids are crossing over at 80Hz. The subs uses a filter with a 24db slope while the mids are doing ok with a 12db slope as they fall off around 80Hz anyways.
 
Mounting a subwoofer on the side will inevitably cause problems with time delays. However, as you all know the human ear isn't particularly sensitive when it comes to placing low bass sounds. There are normally no problems with sidemounted woofers up to around 150Hz. Just to be on the safe side the crossover was set to a very low 80Hz.

The frequency range of the speaker is 20Hz - 30kHz (+/- 3dB.)
 
Shaping the Baffles

richie00boy said:
Looks like somebody had many hours ahead of them with a chisel and sandpaper on those real wood baffle faces!


All in all the both baffles took a total of 12 hours work. I did not use a chisel. Since it can easily crack the wood. The baffle is made of laminated scandinavian brichwood (I actually bought them in my native in northern sweden). So after carrying them back to the UK I really did not want to take any chances.
The tool I used to shape them was a Dremel MultiPro.

I began by using a highspeed cutter . All the work was done very carefully in order to avoid cutting too deep.


Once the rough cutting was done I sanded the surface with a Sanding Drum.

The image posted show one of the baffles after sanded with the sanding drum.

I finally took a belt-sander and fine sanded the baffles, the result I believe speaks for itself.
 
ultrachrome said:
I'm currently shopping for a crossover for my new project. dbx Driverack comes highly recommneded but has no digital input. My favorite so far is the Rane RPM26z which has a digitial input and an easy to implement volume control.

I think that a digital input is a must. There really isn't much point converting the signal from the CD-Player into analog and then converting it back again. The Rane seems like a good choice, any view of the DAC quality compared to the DCX2496?
While we are at it, I have read a lot about Digital room correction. Speakers such as Canton Digital and Bang & Olufsens BeoLab 5, can be optimized with digital Equalizers nad microphones. Behringer's DEQ2496 appears to be a very cheap alternative, and since we already have a Digital signal adding another component should not degrade the sound. Are there any other products out there I should consider if I want room correction?
 
Ninfendo said:
Mounting a subwoofer on the side will inevitably cause problems with time delays.

Given the proximity of the drivers i don't think you will have an issues at all... what you might well find is that stuffing the ports (making the boxes aperiodic) will allow a more seemless transition to the woofers.

dave
 
Ninfendo said:
I think that a digital input is a must. There really isn't much point converting the signal from the CD-Player into analog and then converting it back again.

In my case, where vinyl is the primamry source digital input is a don't care.... i've pretty much managed to skip the whole Cd debackle (duck) :)

dave
 
planet10 said:


Given the proximity of the drivers i don't think you will have an issues at all... what you might well find is that stuffing the ports (making the boxes aperiodic) will allow a more seemless transition to the woofers.

dave

Putting all the woofers as close together as possible was intended at minimising the Time Delay.
Can you explain the point of stuffing the ports a bit more?
 
Ninfendo said:
Putting all the woofers as close together as possible was intended at minimising the Time Delay.
Can you explain the point of stuffing the ports a bit more?

Generally a bass reflex doesn't usually cross-over well to something below it . Making the ports resistive by stuffing them (polyfill blanke rolled up probably works best in this istance) makes the box look more like sealed, but with a flatter impedance curve (and a flatter 1st derivative of the impedance curve). This usually gives you a better transition to the lower frequancy device.

ie your P13s are midranges and bass reflex for a midrange is rarely a good idea.

As to the woofer on the side, it is omnidirectional below about 4500/w where w is the width of your baffle in inches (in this case the side of the box), and well under a 1/2 wavelength distance drom the P13s (just under 70 inches at 100 Hz) at crossover.

dave
 
planet10 said:


Generally a bass reflex doesn't usually cross-over well to something below it . Making the ports resistive by stuffing them (polyfill blanke rolled up probably works best in this istance) makes the box look more like sealed, but with a flatter impedance curve (and a flatter 1st derivative of the impedance curve). This usually gives you a better transition to the lower frequancy device.

ie your P13s are midranges and bass reflex for a midrange is rarely a good idea.

As to the woofer on the side, it is omnidirectional below about 4500/w where w is the width of your baffle in inches (in this case the side of the box), and well under a 1/2 wavelength distance drom the P13s (just under 70 inches at 100 Hz) at crossover.

dave

Once I get the digital crossover I can easily start experimenting with the falloff of the sub. Stuffing the ports would cause the fallof of the mids to start earlier, hence yield a flatter fallof. Using 24 dB/octave filters for the sub might then not be a good idea, with a flatter falloff for the midrange, however I really don't want the subs to play above 100Hz.

I will use active highpass filter for the mid, currently the plan is to set the crossover frequency at 80Hz (as described earlier).
 
Noksukau said:
I was a little shocked to see that you live in the UK as initially it looked like a barmy Yank design to fill a ranch with music! :D (no offense to you or our time-delayed friends of course).

Ben

Hmm, I think it's time that we once and for all get rid of some common misconception. North American designs do tend to be larger than their UK counterparts. I do think there is a good reason for this, as it all boils down to living standards. In the US living rooms tend to be larger, and sound absorbing carpets on the floor are quite common. These living rooms can thus accommodate large speakers.

I come originally from Northern Sweden but live in the UK since three years. Property in the UK is dreadfully expensive and flats and houses are miniscule in size. In the UK I pay something like US$ 2000 per month in rent. Back home we have bathrooms (including the Sauna) which are the size of my current house.

I really don't think we can rightfully criticize the size of some American speaker designs, as it is the relatively low living standards in the UK which are to blame for Ben's prejudice.