"Shadow of The Colossus" build thread

[Legis]

Something to consider: going to an active system with DSP crossover. Active with DEQX transformed my horn system...

I have had active systems, last one was battery powered spdif in/spdif out Nanodigi + separate dacs and amp modules for each band with my 2-way synergy horns + TH woofers. Liked them passive (electrical + acoustical) xo'ed much more. Direct coupling to an amplifier is not always the best, horns seem to like some electrical losses (series connected woofers feeding the same horns instead of parallel connected, series res attenuation/level matching, high-ish output impedance amp like tubes etc.).

Colossuses should be very simple speakers acoustically, no need for delays, notch filters and only 6-12db/oct electrical slopes. Need for level matching should be also minimal. Very passive compatible speaker, dsp goes to waste and only adds complexion. The "purist approach" works best in simple speakers. A speaker system needing more electrical tayloring the dsp-active approach quickly becomes the lesser evil, when applied correctly.

 

[Legis]

Couple pics of the raw mid modules before they start to look like something else.

Material is 25mm MDF, front baffle also has 12mm plywood laminated behind it. The edges are "miter cut"/45deg except at the center hole in which the horn is mounted. The braces are quite hefty 40mm thick and 30mm wide plywood and there are plenty of them supporting the already narrow areas that need to be braced.

I wonder how does the box's standing wave spectrum look like with this geometry.

 

[Legis]

Lots of acrylic mass to glue the felts. Might damp some hf panel resonances a bit. Acrylic mass has good price to inert mass ratio, it's quite like chewed bubble gum when dried.

 

[Legis]

Little progress. Tomorrow the lining will be ready (phew).

 

[xrk971]

Very cool and very impressive manly man speakers!

 

[Legis]

Thanks xrk! I also drew a synergy/unity mid modules (only a crude picture) but did not want to go that route again, too much hassle to get it right. Instead I chose this synergy/point source emulation with direct radiators with much more Sd and way less hassle. Back to basics.

Btw. does anybody know how to sim the inner air space of the box when it's not rectangular? I suppose the O-ring box shape like this dampens the systemic resonance at least somewhat. The back wave sees approx. 3m long (lined) pathway until it reaches the back of the cone again or sth like that. I didnt fully realize this, but now they have the lining almost done the inner space seems very damped regarding the standing wave behaviour when speaked/beatboxed inside the cabinet. Sounds good, but I dont wanna loose too much sensitivity in the upper bass region due to very damped systemic resonnace. Hopefully this is not the case and it dampens/spreads only the standing waves but the air springs stays non-lossy at system resonance. If the impedance peak is at 80-100ohm the guild of the kick bass is happy.

 

[Legis]

Just finished lining the first enclosure.

 

[Legis]

Little progress. Couple more layers to go for the front baffle. I might opt not to polish the surface as it highlights all the hours of not doing any prework and in-between sandings

After first wood oil/wax (nice matte):

An externally hosted image should be here but it was not working when we last tested it.

After second layer and mechanical wet-polishing:

 

[Legis]

Found this nice clear coat wood oil/wax (Osmo Color TopOil) that can be applied like a regular laquer, it evens out very smoothly when applied with a "short hair" microfibre roller and a medium-thick coat and it leaves very nice satin finish with only one coat (on top of Osmo Color Woodwax). And it is durable even though it is not a plastic coat but more natural. Quite ideal stuff for a diyer to get close to commercial grade finish, the best one I have ever tried.

I still don't have the M6 inserts and inner cabling that were ordered 1,5 weeks ago from france.

 

[Ro808]

Snoop will be jealous...

Btw, I assume the cutouts in the horns once accommodated the diamond dome tweets?

 

[phase_accurate]

Don't think so ! IIRC the Augspurger uses 4 15" woofers. And the optional subs are 18".

I once read that they developed this giant monitor because some studios were fed up of having to change defective woofers often when they had clients form the hip-hop scene.

Regards

Charles

 

[manninen]

Drivers are maybe not gonna rip thru the Augspurgers baffle, bolted down with 10 bolts.

10000Watts? amp PMPO and driver power handling summed together?

 

[Legis]

Finally standing, tall and fat (big bones), like a fake wall.

Progression thus far (thank you for noticing the zinc plated bolts but I'm aware ):

 

[Legis]

Snoop will be jealous...

Btw, I assume the cutouts in the horns once accommodated the diamond dome tweets?

Nice find Should thump nicely, like a member of the guild of the kick bass, regardless the ported box's gd

Yep the horn in the pic is Usher D3's horn which has the cutout for the diamond tweeters. Just for demonstration, the Colossus will get it's own Yuichi horn, machined in Hungary out of from birch ply and slightly thicher lips than in original.

 

[Legis]

Here's the L/R response of the mid modules from the listening spot. This time with full sand electronics, no tubes anywhere. Mic not calibrated and the amp is not "reference" and has little less than 1dB of attenuation already at 20Hz.

 

[Legis]

Here's a short video of the midmodules without xo/full range from yesterday. Different songs with different bass sounds, many have wide bw "fast" kick bass components and pressure transients (also the Madonna has) which is the territory ruled by the guild of the kick bass.

Time for headphones: Mid-matrix testing - YouTube

Nice dry kick also with these 12" Fanes and well behaved cones. Not identical feeling due to carbon fibre cones but on average very similar and recognizeable Fane sound how they seem to voice these kind of 12-15" midbass drivers.

 

[Ro808]

Nice find Should thump nicely, like a member of the guild of the kick bass, regardless the ported box's gd

Closed box bass is better, but requires a lot of Sd, which you have in abundance.
An optimised/critically damped BR - with foam ports > semi-aperiodic, or a bit more complicated: a matrix BR (see attached image) may be an acceptable compromise.

Yep the horn in the pic is Usher D3's horn which has the cutout for the diamond tweeters. Just for demonstration, the Colossus will get it's own Yuichi horn, machined in Hungary out of from birch ply and slightly thicher lips than in original.

The horns are made by the company located in Szombathely?

Even Joseph Crowe's 150Hz Arai horns would probably fit in your cabs.

 

[Legis]

Yes the br could be taylored to have even 2nd order rolloff, but would it give any more efficiency vs. sealed then, 1-3dB maybe? Fully aperiodic (which needs very large leak vent area to be very non-resonant) would be less sensitive than sealed.

Also leaking systems cannot pressurize the room so no room gain below the time constant of the leak/tuning freq. Sealed system on the other hand goes to DC in a ideally sealed room. Pressure transients are very nice from a big sealed Sd!

Also I'm sceptical towards transforming sound to heat mechanically in any form let it be silicone damped surrounds/spiders, rubber surrounds, conductive voice coil formers or air flow resistance. Kills the dynamics and the tactile quality (feeling on the skin) of the first wave front or something imo. Maybe the "breaking" is not linear, the faster the mechanics try to move the harder the breaking effect is? I like the sound of high Qms/low Rms woofers and making them into aperiodic (or stuffing the sealed box fully) would just add the same thing ie. mechanical damping and the high Qms goes to sh*t Can also be formulated that the location of the voice coil is ideally determined by the motor's driving current, and not the mechanical non-linear friction imposed by said things on the moving parts.

Just thoughts in the current state of knowledge and experience. And of course I'm pro-sealed (and pro low-loss mechanical systems) after making these, so no objectivity here whatsoever Lots of ways to skin the cat and in reality almost everything can be made to sound good.

Yes the Athos Audio makes the horns. I have never used them before.

 

[Ro808]

Yes the br could be taylored to have even 2nd order rolloff, but would it give any more efficiency vs. sealed then, 1-3dB maybe? Fully aperiodic (which needs very large leak vent area to be very non-resonant) would be less sensitive than sealed.

Fully aperiodic doesn't help sensitivity, true.

My idea is more along the lines of oversized vents, in which the actual (open-cell) foam ports are mounted.

Also I'm sceptical towards transforming sound to heat mechanically in any form let it be silicone damped surrounds/spiders, rubber surrounds, conductive voice coil formers or air flow resistance. Kills the dynamics and the tactile quality (feeling on the skin) of the first wave front or something imo. Maybe the "breaking" is not linear, the faster the mechanics try to move the harder the breaking effect is? I like the sound of high Qms/low Rms woofers and making them into aperiodic (or stuffing the sealed box fully) would just add the same thing ie. mechanical damping and the high Qms goes to sh*t.

Some say material/shape/weight of the cone and suspension don't matter much, as long as the motor is strong enough.
Like you, I don't think this is the case (at all).

Currently I'm using 15" woofers with Qms: 13.000 and Rms: 1.332 Kg/s.

Speaking of Fane, I still have a pair of these laying around:

 

[tmuikku]

Hi, what is high Qms value? Checked some random pro woofers and they seem to be around Qms 6 +-1 as well as your 12" and 15" Fanes in this project. Are all pro woofers high Qms? Doing some coffee break reading. Thanks!