Adire Audio HE12.1 towers

[mike stehr]

I burned my mere pittance of a income tax check on a pair of Adire Audio HE12.1 coaxial speakers. With DIY tower speakers, port tuned to around 35Hz I guess.

These were kits based on the Eminence Beta 12CX woofer, with the APT50 phenolic tweeter driver.

 

http://www.eminence.com/speakers/speaker-detail/?model=Beta_12CX

 

Adire did some modifications to the tweeter for better linearity or WTF ever...(note the little pieces of foam around the phase plug)

Adire Audio sold the coaxials with two four inch ports, all the crossover parts, and some terminal cups. The user had to come up with enclosures/cabinets. There were two different options for enclosures, a smaller sealed version, (w/LF roll-off at around 45-50Hz) and the ported bass reflex tower versions like these.
I haven't measure the F3, but it's claimed to be 35Hz...I'll find out...

 

Turned out I knew the guy from over ten years ago, he built these as a project when he was in college. The Force Audio days...some serious bass fanatics...

He knocked 50 bucks off them because he remembered me...good thing...these enclosures were done with LineX bed liner coating. Which can look excellent, but in this case it was a rushed job, which IMHO was botched. Uneven, with this goofy metallic looking shine, and rough as 30 year old pavement.

You know ten years go by, the guy gets married, has a kid with one on the way, so his hobby now is restoring a foreclosed home.

 

The speakers sit in the basement forgotten, until the wife says flog them.

 

When I picked them up, he had a couple dogs. No biggee...A minute or two later two cats materialize from out of nowhere. Barb is allergic to cats...oh boy...
When I got them in my place, Barb instantly noticed cat on them, and immediately started to wipe them down. She was rather repulsed by the finish as well.
One of them kitties clawed a speaker cone as well. (may be visible in pic)

 

I coated the 12" cones in Dammar mixed with turpentine, to make the cones look better.

 

So out comes the palm sander, 100 grit, and labor. These are nice cabinets, with bracing...3/4" Birch plywood. But once I started knocking down the bed liner coating, I soon find weird gouges, cuts, holes...
Even the terminal cups and ports were done in bed liner coating. The passive crossovers weren't spared either.
I pulled a port and the coating started to peel off...I thought cool, I can just peel the crap off...until I started peeling a couple layers of plywood as well. Oops! Thank goodness for wood bondo. That was a 10 dollar mistake...

 

I sanded, used spackle to level things out, and fill holes. Sanded everything smooth again. I then hit them with semi-gloss black latex, using a 3/8" knap roller.
Two coats...
And they still need to be smoothed out with more spackle, sanded, and re-painted.

 

I told Barb f*ck it, they can hang until I'm more flush and do it later when it's warmer.

 

His passive crossover layout/soldering work was okay, good enough to get the job done. But too much silicone caulk/sealer for me, and with rotted dry solder joints caused by said silicone. Plus Adire provided this lousy thin through hole fiberglass board to lay parts out on...about 1/32" thick junk.
Adire provided decent passive parts, (Clarity Cap, Solen inductors) except resistors, which are the usual sand cast boat jobs.

 

I have some 3/4" plywood painted red that I'll layout and solder the parts onto, and have the crossover networks mounted outside the cabinets for now.
He had no padding of any sort in the enclosures...I'll start with polyfil, but may have to line the sides with foam or some sort of padding.

 

Then I'll break out the signal generator, and the VTVM, and run some sine waves to determine the low-end roll-off, and listen for any weird peaks/nulls, and figure how to address them.

 

And I thought they would be plug and play...oh well...

 

I've been wanting tower enclosures so the coaxial is more at ear level.
These are perfect for the task...it would cost what I paid in plywood alone to build these. And I got the speaker drivers as well.
Pretty much source point sound with a coincident type speaker, set up right, they are like headphones in a way.

 

I have a pair of CDK/AMK 12" coaxials I want to use/try, but will take some work with drilling, and affixing T-nuts...

 

Mike

 

[JL Sargent]

Looking around I found this guy and the pair he built. Interesting speakers and even more interesting if you pull off the coaxial swap.

 

http://cognitivevent.com/av_he12.html

Edited March 1, 2015 by JL Sargent

[mike stehr]

Looking around I found this guy and the pair he built. Interesting speakers and even more interesting if you pull off the coaxial swap.

 

http://cognitivevent.com/av_he12.html

 

Yeah, I'm glad that website is still around...it helped out a bit. Unfortunately, there is no schematic of the HE12.1 crossover floating about online. There is the HE10.1 build manual and schematic, but it's not even close to the HE12.1.

 

Between this guy and his explanations of the HE12.1 crossover from his site, and backwards engineering the crossovers I have, there may have been an error in the xover from the person I bought them from.

 

 

Sorry about the lousy image, but it gets the point across. According to the guy with the website, the 20 ohm resistor and .18 millihenrie inductor are in parallel before the tweeter.

(keep in mind the guy has a typo error when he explains this, describing the differences between the HE12.1 crossover, and the Mark II version.

 

The builder had the inductor/resistor bridged together, and series wired. I would think they would be in parallel.

 

These are the CDK coaxials I would like to eventually try in the enclosures. They drop in, but the basket flanges are a bit wider. The looks of the CDKs make the Eminence appear cheesy. But the enclosures are likely optimized for the Beta 12CX woofer. I'm gonna try the CDKs, however. 

 

[mike stehr]

Up and going, for a first take with the crossovers lashed-up on the floor.

 

They had no padding inside them at all, and had a hollow ring when tapped on the speaker. So I put about 3/4 of a pound of polyfil inside the middle chamber, and behind the driver in the upper chamber, layered around the sides in each tower.

 

I didn't think it would, but that killed the hollow ring sound when tapped on the cone.

 

With regard to the .18mh inductor and 20 ohm resistor before the tweeter, I went ahead and connected them in parallel. I can't see why they would bridge a inductor across a resistor, (or visa-versa) and connect them in series?

The networks are the stock Adire parts, Clarity cap and Solen inductors. Except I swapped out the 22uF non-polar Bennic for a Jantzen 22uF metal polyprop in the zobel network.

 

They sound rather nice so far. I still need to measure the low end roll-off, but they seem to get down in the lower registers from listening...not loud, but there. Not quite as sensitive as a Cornwall, but still boogies very well with a HK 330B receiver.

 

I may shorten a port, and up the F3...but I need to determine where it's at first, and listen for peaks before I go hog-wild.

 

The crummy pics make them look better...but they still have flaws...

 

Edited March 2, 2015 by mike stehr

[JL Sargent]

They look good. You might just listen to them as is for a while.

[Deang]

I like reading about your projects and I really like coaxials - it's a great sound.

[mike stehr]

Thanks there...Uh, CSM...

 

I really like coaxials as well. They have their compromises like all speakers, but for imaging they are tough to beat. At least in my smaller LR with a semi-nearfield situation.

The Cornwalls aren't going anywhere, they have that big sound about them that I like and don't want to give up on. They can image well, but in a smaller living room I can't get back away from them enough to really get the imaging they can do.

 

And I have heard Cornwalls in a room roughly 25' X 30'. They were out more in the center of the room, about 12 feet apart, and the LP is around at 12-13 feet. (roughly)

Then they could image rather nicely.

 

Once I kick the Cornwalls out of the LR, I can set the coax speakers back further, and get them closer together.

 

Just to make ya wince a bit, here is a Adire HE12.1 xover network lashed up on a phonebook w/clip-leads. One can never have enough clip-leads...

Other than rectifying the crossover problem, I've taken the advice of Mr. Sargent and have been just listening to them.

 

I've been meaning to measure them, but when I go about it the GF fires up the stereo.

 

But from listening, they sound like they are getting down into the upper 30Hz region I would guess. I do have the pair of SVS 16/46 subwoofers if I want to get all sloppy with bass. If I recall, the coaxials I've listened to in the past have always seemed to mesh better with the SVS over the Cornwalls. I usually listen to the Cornwalls alone with music. 

 

 

Mike

Edited March 6, 2015 by mike stehr

[mike stehr]

These are better than the phone book and clip-lead option, and will get me by until I'm more flush. The existing boat resistors (w/hokey leads) will then be changed out for Mills.

I may experiment with the padding resistor value first...

 

Nothin' fancy...Cheap ghetto style...couldn't afford black paint or stand-offs. Definitely better that what they were.

 

 

[Deang]

Nice build actually - pretty much how I build when I'm building for myself. I don't give myself the anal retentive builds my customers get. I did Jordan's Jubilee networks just like that - I ran buss wire between two barrier strips on an 18" painted piece of wood and just started laying the parts out. The layout usually figures itself out, I think you know what I mean!

[mike stehr]

The layout usually figures itself out, I think you know what I mean!

 

Yup. I'll look at the schematic, and then sit down and draw the layout, trying to make things as simple as possible.

In this case however, there was no schematic. I had to figure it out from looking over the original networks.

[mike stehr]

^{Over the weekend I dug out the HP 400H VTVM and a Heathkit audio signal generator, for a quick and dirty way to determine the vent tuning frequency of each enclosure. (not F3)}

^{Watching the VTVM needle for a null between two peaks, the port/vent tuning frequency of the enclosures are around 33-35Hz...like the guy who sold them said. Listening to sine waves at 35Hz, they can really growl. So it seems so, I suppose.}

 

^{At 30Hz and below, things really drop quickly. The second peak on the VTVM meter tops out at 58-60Hz, with a slight blip at around 100Hz. I figured there would be a loud peak at around 60Hz when doing sweeps listening for said peaks} 

 

^{Then I connected the audio generator to a amplifier to do sweeps on the LF to listen for any objectionable peaks. At 60Hz, things sounded fine...the peak is around 100-103Hz.}

^{This may be room gain contributing to the peak.}

 

^{I took some more polyfil and stuffed another 1/4 pound or so in the lower chamber around the port, but not blocking it.}

^{It helped a bit more, but I think I'm going line the insides of the enclosures with some sort of padding, they still have that bit of hollow sound. (though much better than before)}

^{As far as shortening the port, I'll just leave it alone or get another pair of 4" diameter ports to experiment with down the road.}

 

^{They have a surprising amount of low-end bass, actually.}

 

^{I found a couple of 20 ohm 12 watt Mills resistors stashed away, so I put those in the tweeter padding spot. The 2.4uF (measured 2.2uF) Clarity cap was swapped out for a Jantzen Silver 1.0uF cap, with a Bennic 1.5uF cap bridged across the Jantzen Silver cap. (still measure out at 2.2uF)} 

 

^{I dunno if I'm into Clarity capacitors...}

 

^{That made the top-end sound better and less grainy...I think it's the resistor that helped most...who knows...it sounds better.}

^{Next, I'll swap out the 4.7uF Clarity Cap for something, and use a 11 ohm Mills in the Zobel position.}

 

^{Things are sounding a little nicer as I go...the stereo imaging is great.}