Crossover design for subwoofer with Orca speakers

[Hank Murrow]

Dr.Bob;

I have a Marchand XM-9 fourth-order X-over that uses a four resistor block which fits in a socket to alter the X-over frequency. Perhaps you could devise a mod for the simpler Marchand unit to improvise easy interchangeability of the X-over frequency.

Cheers, Hank in Eugene

[Grainger49]

Hank,

I'm toying with some things... can you post a link to the passive crossover?

Thanks! ! !

[Clark B.]

Paul, yes the Thrasher shrank recently.  It is now around 1cu ft and tuned to 45/50 hz.  And a new feature for 2014 is that the spray painted logo is now "optional" rather than "standard."

The exterior dims are almost the same exact size as a standard bankers box. This smaller cabinet gives a slightly leaner, tighter bass response and therefore better transition into midrange.  The "new" GRS bofu drivers are much less obvious to simulate than the original pioneers, but they come out well, sonically speaking, once they are broken in and in a decent enough cabinet.  The tweeter x/o is a 2 ufd cap for a slightly bright response.  Thinking small venue PA on that X/O point.  But i usually offer to customize this crossover point depending upon the application.   

I thought on it some more last night and I am definitely going to put together some beefy buckets and mess around with them some.  Its too cheap of a project to pass up.

Cheers,

Clark

[Paul Joppa]

Thanks, Clark!

I was curious just on principle - now that I see the picture I am wondering about a quad of them with a Tode and a bass guitar...

[Hank Murrow]

Hey Grainger; Long time no see! I think it was the Vancouver VSAC and that wonderful final Jacqui Naylor concert.

My Marchand X-over is the 3-way XM-9, which is a solid state 24 Db/octave active design. Dead silent, I think it has done a good job in every application in which I tried it. Prices for these have gone up some since I purchased mine, and I got the kit version sans casework, which I fabricated myself.       http://www.marchandelec.com/xm9.html

That said, I think I would have Paul Birkeland build a tube X-over for me some day if I get System-antsy again.

Cheers, Hank in Eugene

[Clark B.]

Thanks, Clark!

I was curious just on principle - now that I see the picture I am wondering about a quad of them with a Tode and a bass guitar...

I'll try and set that up some time for you at our shop.  You bring Tode and bass guitar, I'll serve up the thrashers and a nice beverage for you.

[pboser]

Clark,
Any thought of a knocked down (assemble it yourself) version of the Thrasher?  It would save you some labor, might make shipping across the country cheaper, and would add some fun for the buyer. 
Pete

[Clark B.]

Good news: I just got budgetary re-approval from my friend Ryan Spence who helped design and build this vert ramp to upgrade the previous generation (big) Thrasher speaker system that is currently installed with a pair of Mini Thrashers standing atop a pair of bucket subs.

Footage of the sound at lowish volumes of the current sound system in this video:



Footage of some really good skating in this video (tip: loud heavy metal sound track you might want to turn the volume down before watching)



This is the largest vert ramp in washington state, privately owned and housed in lush, forested land owned by Grindline skates, who is a "design and build" skatepark company (they've done most of the city's skateparks). 

The issue we were having is that the current speakers are essentially being hung in free air (its a canvas tent), so they are not getting any of their intended bass reinforcement from being in a room.   Even in the free air setting, they still make plenty of bass when they are warmed up and playing loud volumes, but the skaters, ironically, are asking for a system that plays nicer and has more bass presence at lower volumes.  Its a privately owned ramp, so alot of the sessions here are actually just one or two folks trading turns and mentally keeping themselves totally "in the zone," which means lower volumes. 

So the new bucket sub/ mini thrasher combos are instead going to be placed in the corners on top of one side of the ramp (that the skaters hang out on), and then toed in to make a nice stereo field across the ramp (where the spectators hang out).  This will at least give them some sort of platform from which to get 1/2 space reinforcement, and also will be at ear level and toed in to be heard very nicely on the spectator's side of the ramp.  The ramp is almost 50 feet long, so that will give a huge, wide stereo field as well, which is great with Jazz music.  The ramp was just completed last year and has been broken in heavily over the winter, so this summer the owners are expecting alot of visitors.

Fun times,

Clark

[docbob52]

Clark, 

The Bucket sub, from what I have read, was designed to resonate and reverberate like a musical instrument:  much like your Orca's-- and not to have a cabinet dead quiet.  It would be interesting to all of us that you build it as suggested, and the compare it to your highly upgraded form.

[Clark B.]

I'll take your advice on that, then.  Thanks for the heads up! 

Btw, the orcas aren't necessarily designed to resonate much at all...just that they do so in a "natural sounding" manner that is not "parasitic" to the music.  Some subjectivity here, but overall we are going for a very rigid enclosure.

Clark

[bernieclub]

Getting back to the original topic, I notice that Parts-Express recently ran a sale on plate amps, and a pair of 25 watters would come in at about $50.   Is it a viable idea to use the amps as a crossover only, maybe by loading the output with a 50 ohm or so resister, and feeding that signal to a better and more powerful amp?   If crossing at 100 hz, is the quality of the amp even audible? 

[bernieclub]

OK, I promise not to ask any more rhetorical questions!

[Clark B.]

Bernie,

The bucket sub appears to be geared towards high power input levels. They are claiming that the higher the power/ greater current drive the amp, the better. 

[bernieclub]

Clark,

Thanks for clarification on the bucket.   Like the original poster, I also thought for some time about building a sub crossover to power an old but decent SS amp.   I even pondered modding my old FPII into the crossover, but it proved to be too challenging for my limited knowledge.   So....when I saw the low price of a low powered plate amp, I envisioned daisy chaining the plate amp into the powerful SS amp, using the plate as the crossover.   I guess it will be one of those "try it and see" experiments.