the ancient urge to build a dual-woofer three-way

Pat McGinty

Senior Member
We’ve been building modular systems like Kite/Predator and Black Bird/Kingfisher and liking it a lot.


But one guy recently picked a nit that there can be too many wires with the modular idea. He likes the point that a bookshelf guy can add a bass system later on, but what about the guy who knows from the get-go that he wants a big boy rig, can't we clean that up a little?

I'm not sure I agree that the extra power cords and signal cables are a problem, especially compared to the tangle at the back of a conventional rack system. But, anyway, OK, let's figure. Right away the idea has three positives:

1) Less cabinet cost. Labor is the dominant cost; building a small six sided box with some holes in it, veneered, coated and populated takes pretty much the same amount of time as making a larger one. Building two boxes takes about half the time as four.

2) Hypex’s dandy new three channel N-Core based plate actually costs a bit less than the two plates we’re now using in the two box idea. There's no question about the quality and they're made in Denmark, so the strong dollar against the Euro really does the trick. 100Wx500x500W.

3) The combined labor and amp savings more than cover the cost of adding an additional Satori 9.5". I figure we can come in below Kite/Kingfisher's cost and do twice as much work in the bass. So if the aim is value, duh.

Since we already know the optimal air volumes for each driver we can easily work out the choices for cabinet dimensions. Looks like 11Wx16Dx47H will work including a bay below the amp for the streamer. Ideal tweeter height. Modest size. Potent.

Whaddya think? Make a prototype and see what happens?

DWTW v2.jpg
 

Prime Minister

Site Owner
Staff member
Damn. I'm outdated already! :)

Knowing what the Kites can do, I can't think that this new big brother would be anything but a very good thing.

Can I upgrade mine to the Hypex? :)
 

Pat McGinty

Senior Member
Yeah, as expected, the tech is accelerating. Audio is accustomed to a mature and stable tech so applecarts will fly.

As more players enter the field it could get pretty wild.

Remember PCs in the 80s?

I faked the idea with Kites and two pair of Kingfisher and it was quite yummy.
 

Pat McGinty

Senior Member
I'll bet it was. But I think I'd likely still prefer a distributed bass setup in my own room.
Here's the bottom octave enthusiast's solution for properly timed arrival, correct image placement - which IS important - and flat into the teens at stupid amplitudes with snappy rise and settle times. Each driver should be barely working, so nice dynamics. One 1KW plate will do the trick since the N-Core is happy with 2 ohms.

I'll admit that this idea will have the faint whiff of divorce for some guys ;-)

DWTW+LF.jpg
 

Ernie

Activated
So, technology has caught up to the idea of 'No compromise'.

About ten years ago, I listened to Joe D'Appolito describe the process of designing Snell's latest flagship, the name of which escapes me. (Reference A7?) I do remember them being $35K, and being released with the new Marantz Reference gear. The primary point he made dealt with choosing what you had to have, and what you would settle for giving up, in order to bring a design to market. When asked what it would take to build his dream speaker, no compromise, he talked of driver capability, amplification, crossover problems, room response. He summed it up by saying that every fundamental was a compromise, but he saw the possibility of, one day, being able to build that speaker, and it would be a shift from the 'norms' of the day. I wonder if this is what he had in mind, back then.
 
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Build em you won't regret it.
I did build these before we were married and she married me anyway. Love me , love my speakers. Over 40 years later she has developed an addiction to opera and is looking forward to multichannel BlueRay hi rez performances in the great room.

Speakers Front.jpgWoofers Rear View.jpg
 
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No I built them in 1977. The guy that I built them with became my instantaneous best friend. He was a guy that would build a pair of speakers to sell when he needed cash. Somebody introduced us when I was looking for someone to help with the "boxsmithing". He had a roomy workshop and a squared up , zeroed in table saw.

After we sketched them out I said "How much do you think you will need to help me build them" His answer, "Nothing, I just want to hear them" We were best friends from then on, for 17 years, until he deceased in 1994, which is when I turned away from the hobby for about 25 years.

The tweeters are Yamaha Be domes from the NS500 which had a larger magnet than the NS1000 tweeters. The MidRanges are from The NS1000. If one looks closely there is a slight finish mismatch, the NS500 having a shiny lathe turned finish on the top plate versus the NS1000 having a duller nonglare "camera" finish.

The woofers are JBL LE14A. The midbass an LE10A in a sub enclosure.

I was working in the bidness and got everything at dealer cost but they still cost close to US $6,000 in 1976-77. Not including the not inconsiderable labor of constructing them.
 

Pat McGinty

Senior Member
No I built them in 1977. The guy that I built them with became my instantaneous best friend. He was a guy that would build a pair of speakers to sell when he needed cash. Somebody introduced us when I was looking for someone to help with the "boxsmithing". He had a roomy workshop and a squared up , zeroed in table saw.

After we sketched them out I said "How much do you think you will need to help me build them" His answer, "Nothing, I just want to hear them" We were best friends from then on, for 17 years, until he deceased in 1994, which is when I turned away from the hobby for about 25 years.

The tweeters are Yamaha Be domes from the NS500 which had a larger magnet than the NS1000 tweeters. The MidRanges are from The NS1000. If one looks closely there is a slight finish mismatch, the NS500 having a shiny lathe turned finish on the top plate versus the NS1000 having a duller nonglare "camera" finish.

The woofers are JBL LE14A. The midbass an LE10A in a sub enclosure.

I was working in the bidness and got everything at dealer cost but they still cost close to US $6,000 in 1976-77. Not including the not inconsiderable labor of constructing them.
There's nothing like a line array. If you're going all-out there really is no other path.

I could write a term paper on the advantages, there are so many, but suffice it to say that the radiation pattern alone seals the deal. You do hafta throw some dough at it, though.

Here's a 'pic-story' of the design, build and installation of one of our most fun arrays that used forty inches of Mundorf AMT next to six SB 17s. One amp channel for each sub, one for each pair of SB 17s and one for the tweeter. So twelve amps. Deqx for DSP. That thing could lift you out of your seat. We trimmed peak output by 13dB so the owner's kids couldn't hurt themselves. Nifty digs, hexagonal room entirely poured concrete and glass, so the line array was the only solution:

 
As we say in my family, "Whether you're rich or poor, it's nice to have money.";)

My late friend built his own solution immediately after we built mine. All JBL , O75, 375 with slant plate disperser, LE12 mid bass and LE15 with PR15 on the back. JBL later made a studio monitor with exactly this complement but I don't think they had it in the lineup in 1977-78 when he built his. Sort of an S8R + the plus being the LE12. He "merely" triamped it and I helped him accomplish that and designed and built a crossover for him. They sounded great too but we never had them in the same room because all of them weighed as much as refrigerators.

My recollection is that we used KorPine 80 which was the densest one inch thick particle board you could buy at the time. We built the boxes in his third floor studio and carried them down a very long straight stairway. Drivers installed on final site. We had a lot of fun "playing stereo".
The cabinet has struts between the side walls about three of them to discourage vibration. The Exxon NevaMar (Formica ) helps too making it a composite. I considered installing some on the interior but that seemed a little crazy.

I do like line arrays and Be Domes.
 
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Pat McGinty

Senior Member
As we say in my family, "Whether you're rich or poor, it's nice to have money.";)

My late friend built his own solution immediately after we built mine. All JBL , O75, 375 with slant plate disperser, LE12 mid bass and LE15 with PR15 on the back. JBL later made a studio monitor with exactly this complement but I don't think they had it in the lineup in 1977-78 when he built his. Sort of an S8R + the plus being the LE12. He "merely" triamped it and I helped him accomplish that and designed and built a crossover for him. They sounded great too but we never had them in the same room because all of them weighed as much as refrigerators.

My recollection is that we used KorPine 80 which was the densest one inch thick particle board you could buy at the time. We built the boxes in his third floor studio and carried them down a very long straight stairway. Drivers installed on final site. We had a lot of fun "playing stereo".
The cabinet has struts between the side walls about three of them to discourage vibration. The Exxon NevaMar (Formica ) helps too making it a composite. I considered installing some on the interior but that seemed a little crazy.

I do like line arrays and Be Domes.
That guy started with nothing, married his high school sweatheart and, apparently, had a knack for understanding risk. Funny as heck: seems that rig was his first descent stereo; he sat down for a first listen and was surprised by (what we used to call) the stereo effect - that phantom images appeared across the stage. A new experience! I was dumbfounded. Anyway, funny, and certainly the biggest in-walls I've ever seen.

Never could figure out how those JBL slant lens thingies were supposed to work, but they sure looked cool. Used to drive past their nice, big plant all of the time, but never went in; regret it now.

But, yeah, enormous and heavy speakers, ugh. When you have to move them first and then populate you know you've gone off the deep end. Am thinking that, hence forth, and being a tad on the old-and-worn-out side, the tall arrays need to be broken down into several modules.

Back in the Infinity Ref 5 days, Arnie Nudell realized that an LF enclosure could actually be quite flimsy. He reasoned that, even though a panel might want to ring like crazy at, say, 250Hz, if you're only activating it below 100Hz you're perfectly fine. I use that principle to excellent result - move the panel resonances into the stop band and forget about 'em. Saves a ton of weight. And since subresonant systems already are edging toward the small size, the problem kinda fixes itself.
 

Pat McGinty

Senior Member
Now we get to find out how these perform. 100x500x500W, so we oughta be able to do some damage. Haven't listened to the N-Core in a while, hope reality lives up to memory. Can't beat the selection of inputs, hope "autodetect" works as promised. It appears that you can input SPDIF to the first unit, then send AES to the following units. That would be nice - to run 110ohm AES wire with XLRs rather than 75ohm RG59 with RCAs (blech!) We'll see.....

I will say that the software is not for the uninitiated.

20190815_134808.jpg
 

Prime Minister

Site Owner
Staff member
Now we get to find out how these perform. 100x500x500W, so we oughta be able to do some damage. Haven't listened to the N-Core in a while, hope reality lives up to memory. Can't beat the selection of inputs, hope "autodetect" works as promised. It appears that you can input SPDIF to the first unit, then send AES to the following units. That would be nice - to run 110ohm AES wire with XLRs rather than 75ohm RG59 with RCAs (blech!) We'll see.....

I will say that the software is not for the uninitiated.

View attachment 15854
Among other things, the autodetect seems very good. Can't wait to hear your impressions.
 

Pat McGinty

Senior Member
Any update on this build, Pat? Love your build threads. So much skill.
Sorry....summer here in the north country is just like floating thru a dream. I've been playing a shamelessly imprudent amount of hookie. 😄

A fake is running and sounds great, but we've yet to actually pull the trigger on a build. Meagan needs to evaluate and sign off, but she's been fiddle faddling too. I figure next week. Thanks for keeping after us.
 

Audio Refugee

Senior Member
Cool! Enjoy your summer. Plenty of time to spend indoors shortly. Was pleased to see the birdy on the enclosure rendering. Inconsequential maybe... but I like it.
 

Pat McGinty

Senior Member
Did stop dilly dallying around the yard with pooch Louie, down in the woods by the stream, and came in for a listening critical session today. There's a mossy spot shaped perfectly for dozing off. A place where the air smells like flowers and fairies come out at dusk. Yeah, soon enough buried in snow.

Up until just now I've been getting ever so slightly softer transients than I'm shooting for. That's a real hot-button issue with me: to qualify it must be capable of swift violence in addition to all of the other qualities that we all hold dear. Frankly, I can be a real pita on that particular issue, or should I say p in my own a? Killer transient tracking is also the key to resolving the fine inner details of timbre. Once you've become accustomed to excellent, it ain't easy to go back.

Anyway, time to dig into the issue. I'd been focusing on filter design, but it turns out that there are also numerous combinations of settings for how the DAC operates - which is a new idea for me - normally you get no control, those settings are baked in by the DAC designer. So kudos to Hypex. I was elated to discover that I'd been merely using a combination of settings that didn't quite suit my reqs.

Click, click, click and hit the right combo. Yes, indeed, the N-Core can serve up the kind of viciously quick signal tracking that we've been accustomed to with minidsp pwr-ice. Sweet and effortless. Much mo' power. It's really hard to believe at the price.

Just for giggles, I dragged out a couple of twin 20-30 Hertzers, applied FA252s - 2x250 bridged to 1x500 and relieved the twin 9.5" Satoris of that bottom duty. Dandy!

Now I just gotta get Meagan over here. She's at least as much of a pain as I am, worse actually, and we don't go forward without her blessing. Kid's got the chops.
 
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