New Project - Kickin' A-- and Taking Names!

[toddalin]

I am working on a new build that should kick butt over most systems, is maintenance free (i.e., no foams to ever replace or magnets to recharge), and uses no horns that can be peaky or honky, yet provides all the volume and dynamics you could want.

At this point I've assembled the components, and only lack for making new cabinets for the mid-range woofers (~0.75 cu ft).

The system starts with 2241H as the basis. These are mounted in custom made cabinets (to JBL specs) just under 7 cu ft and tuned to ~32-33 Hz. The cabinets are 24" x 21" x 30" deep. These were used in a church and are in absolutely perfect condition without a scratch on them. The cabinets look absolutely JBL, complete with JBL logos and handles that say 2241H, and even "tilt-back" wheels for easy moving. These will go out to ~250 Hz. They can be used horizontally or vertically (21" wide x 24" tall) to reduce edge diffraction with just 1-1/2" to either side of the woofers.

The mids are 2251Js and will be in their own smaller cabints that perch on the 2241s (ala Wilson and a bunch of other high end models). Use of the small cabinet will allow it to be positioned/aimed independant of the woofer and will not take volume from the woofers cabinet. Testing shows these are extremely smooth from ~200-2,500Hz.

From there the system will cross over to a set of modern Heil AMTs.

The system should be very dynamic.

https://images.craigslist.org/00E0E_dBNejnATdas_1200x900.jpg

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[grumpy]

Cool. I bought a pair of those mids as well, with not entirely dissimilar thoughts :)
Would be fun to see/hear when ready!

[toddalin]

Of course all will be invited.

Whole thing (both sides) should be <$1,500 complete when done. Should be lots of bang for the buck!

[SEAWOLF97]

From there the system will cross over to a set of modern Heil AMTs.

I love the Heil AMT's . Most of the ESS systems are 2 ways, the amt handles both
mids & highs.

[toddalin]

I cut out the face plates for the 2251Js. I cut the squares on a table saw, "radiused" three sides (L,T,R) on the table router, and roughed out the speaker holes on a CNC router at the Urban Workshop. The speaker holes were done small and I had to "sneak up" on the speakers' OD with a file. The 2251Js have VERY LITTLE lip on the sides, top, and bottom so the hole has to be fairly accurate. These, at approximately 9-3/4", are too small to fit in a typical 10" speaker's hole.

The 2251J actually serves as a "horn driver" and the factory application mounted them to the rear of a large midrange horn.

The "2241H Series" woofer cabinets are a bit of an enigma. The owner said that they were custom made to JBL specifications. They appear as factory JBL, complete with the "series designation." The thing is, I can find no reference to a "2241H Series" so this would infer that they even went to the trouble to come up with a "factory appearing" badge and even handles. :confused:

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[1audiohack]

Cool sub.

JBL has, or had a custom shop on the Pro side. I have some product from them, slim line array stuff with non production custom horns.

Barry.

[gdmoore28]

"The "2241H Series" woofer cabinets are a bit of an enigma. The owner said that they were custom made to JBL specifications. They appear as factory JBL, complete with the "series designation." The thing is, I can find no reference to a "2241H Series" so this would infer that they even went to the trouble to come up with a "factory appearing" badge and even handles. :confused: "

Hmm. Any chance JBL simply provided those with the woofers? An update to older cabs? Just curious. Can you ask the original owner?

GeeDeeEmm

[toddalin]

Was a C/L find and I don't have the phone # anymore. Also, he was very hard to communicate with (Vietnamese I believe).

When I asked about the woofers, to be sure they were 2241s, he did say that he saw them being installed and that is what the foilcals noted they were. So I asked him to google pics of 2241s and the cones and dust caps are correct. (I expected a 4" dust cap like a 2245 but that's not the case with these.)

[toddalin]

I set up an A/B between the 2241 cabinets and the AlNiCo 2235s in the enlarged L200 cabinets. Obviously, the 2241s are more efficient. But they also bring out lower midrange frequencies, including lower vocals, that the 2235s don't get. I am convinced that the foam edge has to do with this and always missed those frequencies when I replaced the 130As with the 2235s.

Also, the L200s are tuned a bit lower and the 2241s have a nice bit of bass "punch" that comes through.

[toddalin]

Last weekend I cut the faces for the 2251Js and routed the corners round to reduce edge diffraction. These are actually fiberboard. The raised sides/top from the router will be taken down in final sanding.

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Today I cut the top, bottom, and sides out of red oak and glued one together. I only have two big clamps so have to do one at a time. I wanted to do a 45 degree mitered edge, but a straight edge is easier so that's what I settled on. Also, the boards were 4 feet long, so I probably would have come up a hair short in the long run by the time I got the angles in there. I haven't had wood shop in over 50 years (7th grade), and we never got this far
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I also did up acrylic stands in CAD for the Heils, but wanted to check the clearances before wasting a nice piece of acrylic on the laser cutter. A piece of scrap 1/4" ply shows that my calculations were right on and I can cut the acrylic with confidence. I did cut the acrylic feet.

Actually, the clear acrylic is very apropos because Heil's Trademark is "Sound as Clear as Light."

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[gdmoore28]

Hurry up, Todd! We want to see more!

GeeDeeEmm

[bldozier]

:coolness:

[toddalin]

I completed the four sides of both cabinets now and need to do lots of sanding to get everything to mate up, then make the backs.

I won't be able to get back to the workshop until later this week, but that will give the glue a chance to dry. Don't you just hate it when partially dry glue gums up your sand paper?

I peered into the 2241H cabinets with a flashlight and I can see that they put NO INSULATION on the walls. I have the system set up so I can A/B the 2241H cabinet against the modified L200 cabinet, with the "AlNiCo 2235", (both using the 2420/long horn and 2405) and the 2241 cabinet sounds a bit hollow/boxy. I think the insulation should take care of this.

BION, the 2241H brings out the vocals so much better than the 2235. I attribute this (and always have) to the foam edge and heavy cone in the 2235. The 2235s give a "heavy chestiness" compared to the 2241s that just seems unnatural and like it shouldn't be there (and is not with the 2241s) and omits some of the lower midrange with singers like Joni Mitchell just on acoustic guitar or Wurlitzer electric piano.

Of course, I've complained of this since swapping out the 130As to the 2235s over 10 years ago. If I ever had the AlNiCo 2235s redone, I would have them leave out the mass ring (ala, 2234), and run a sub, which I do anyway.

[toddalin]

I ordered 12 rolls of denim insulation and a can of spray adhesive to to the woofer cabinets. Made from recycled jeans, this is not itchy like fiberglass and at 1.8" thick, should line the cabinets nicely without blocking any ports.

https://images.homedepot-static.com/productImages/e152495b-7cea-4268-b6b3-9b944e93e555/svn/ultratouch-denim-insulation-60306-16482-64_1000.jpg

[1audiohack]

.... I can see that they put NO INSULATION!.

They play louder with no insulation. They sound better with. :)

Barry.

[toddalin]

I finshed making the sides, tops, and bottoms and sanded them out.

I need to sand the fronts to mate with the faces and will probably re-route the face curves to go to the edge rather than sand the cabinets back and sanding off the "lip" on the face. Had never used a table router before, and I hope I don't screw up the re-do. The backs will be inset.

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[SEAWOLF97]

.
came for for audio accessories. Was telling me about his 8+ pairs of Klipsh's and some
expensive set that I've never heard of (or remember the name) and 2 pairs of L100's.
He was asking about my bookshelves sitting in living room chairs.
told him they were ESS with the AMT high/mid driver , played a quick demo.

"Those are so clear, and the bass is better than the Century's"

[toddalin]

I finished sanding out the cabinets and primed the faces. I'll glue the faces to the cabinets then sand them flush together.

My wife thinks I should use a black stain rather than an oak or pecan. I decided to use flat head hex screws in black oxide. I'll cut a gasket out of cork on the laser.

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[toddalin]

I roughed out the backs today and will file/sand them for a nice fit.

I also cut cork gaskets for the 2251Js on the laser. There is a real trick to cutting cork in that it curls back on itself, blocks the beam, fouls the arm, etc. I ended up cutting the rings in two passes. In the first pass you erase the outter cut line from the file, cut out the center, and remove it from the machine without moving the cork.

Then you unerase the outter cut line and erase the inner circle to cut the gasket. Even this curls the thin cork a bit so the cut is not exact, but it still makes a nice gasket and will entirely be covered by the woofer frame.

I also tried to cut out a base for the Heils but found that my "acrylic" was actually 3/8" "polycarbonate" and this just made a mess, lots of smoke, and soot in the laser and the beam never even got through the material (60-watt laser run at "3 out of 100"). I'll have to get a piece of acrylic to do these.

[toddalin]

I fit the backs today. One was so tight that it chipped coming back out. I filled it with glue and sanded it out.

The backs will get primer/black, so it shouldn't show..., and it is on the back. If it bothers me, I'll make another before I glue them in place.

[Doctor_Electron]

Toddalin announced:
New Project - Kickin' A-- and Taking Names!

Do you really care WHO they are ?

-D_E-

[toddalin]

Toddalin announced:
New Project - Kickin' A-- and Taking Names!

Do you really care WHO they are ?

-D_E-


You're right! Names..., We don't need no stinkin' names!

[badman]

It's not as bad as it could be because of the small panel size relative to the driver, but some substantial bevels/roundovers would be valuable on that midrange enclosure. Implementing waveguides for the heils would be a strong option too to help match the midrange directivity more closely. This is possible with a tablesaw, 45 degree cuts on the end, and kerfcuts for bending. How's your woodworking layout?

[toddalin]

The edge was run through a 3/4" router on the sides and top. (May be hard to see.) I have routers to 1", but this will probably remain as is now that it's primed.

The faces glue onto the front of the box so the rounded edges stay. The backs are recessed into the boxes.

I'll have to see what happens with directivity.

I picked up some 3/8" acrylic today to make the Heil stands.

[ARMED]

where did you get the denim insulation?

[toddalin]

Home Depot, on-line sells it. If you buy two boxes of 6 rolls, it is enough $$$ to qualify for free shipping (saves $9.95).

But word on AudioKarma is that this is not good for use in speakers because it is too dense and ends up taking up too much cabinet volume.

So, yesterday I took my two boxes, unopened, back to the local HD and they refunded my credit card for the two boxes, and I still didn't pay the $9.95 shipping charge.

The original yellow JBL fiberglass is still available (not from HD), but in 100 square foot rolls.

I'll probably end up using the "pink stuff."

[toddalin]

The UltraTouch all got taken back to the local Home Depot. There is a lesson to be learned here!

Want free shipping from HD on-line??? Order enough stuff to quality for the free shipping, then take back what you don't really want to the local HD. Sure you're are inconvenienced by one trip, but if it's close, it's cheaper than the shipping costs.

Anyway, I cut the 3/8" acrylic bases and feet for the Heils today. Will be totally unique and not bad for $5 worth of materials with leftovers. http://www.audiokarma.org/forums/styles/default/xenforo/clear.png

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I also cut the preliminary vanes for the enclosure but had no 1/16" acrylic so did them from wood. The front vanes need to have a bit of curve removed so they don't hang over the stands and the mount points need to be a little wider for better support. That's why we do up a prototype. These will be stacked like a fence to protect the Heil and an open top plate will be cut with a grill cloth attached to protect the Heil from dust.

Ya gotta love the CNC lasers and what they can do! :)

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Also painted the faces and backs in satin black today.

[toddalin]

These turned out way cool! http://www.audiokarma.org/forums/styles/default/xenforo/smilies/smoking.gif

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[turnitdown]

Kickin' ass and taking initials because names take too long.:dancin:

[1audiohack]

The UltraTouch all got taken back to the local Home Depot. There is a lesson to be learned here!

Want free shipping from HD on-line??? Order enough stuff to quality for the free shipping, then take back what you don't really want to the local HD. Sure you're are inconvenienced by one trip, but if it's close, it's cheaper than the shipping costs...

Really? That’s just shitty.

If you’re going to make a trip to HD anyway, just order what you want and have it shipped to the store, that’s free. And go pick it up.

The added value is you don’t have to wrestle with your conscience.

Barry.

[toddalin]

I glued the faces on and finished the rough sanding for the two cabinets. I'll need to repaint where the material that was removed from the sides/faces (~1/8" all around plus that portion of the box that extended beyond the faces). That's a lot of sanding and my hands and arms haven't been this tired since I was a teenager. http://www.audiokarma.org/forums/styles/default/xenforo/smilies/naughty.gif


I also need to stain the cabinets. I am trying to decide if I should do the paint up, or stain first. Probably stain. Opinions?


We are currently having strong Santa Ana winds, and any painting will have to wait.


Meanwhile, I think that I will mount the speakers and see if there is anything to be gained by going with open baffles. (Could be an epiphany!) This might be the better way to go with the Heils.


I can either just use a capacitor to block the bass, or set my speakers as "small" and let the Yamaha roll them off below 200 Hz and run them full range. Could be interesting.


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[toddalin]

Ready for some A/B between open /closed back performance. http://www.audiokarma.org/forums/styles/default/xenforo/smilies/music.gif


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[toddalin]

OK..., got some RTA screen shots showing the open vs closed back with the 2251Js in ~1/2 cu ft cabinets. The only filtering being used is a 33.6 mfd cap inline with the positive terminal and the speaker is set to "large."

The microphone was placed inline between the two speakers at a distance of 2 meters on a tripod sitting on the couch cushion (legs in). "Close" micing was not performed because this defeats the purpose of the open back. No eq of any type is being used. Of course this does include the effects of the room.

The intent is to run these from ~250 to ~2,500 Hz.

Note that with the closed back, the frequency response "falls" as the frequency is reduced such that between 250 and 2,500 Hz there is a span of about 16 dB (i.e., -83 to -67 dB).

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But with the open back, the frequency response remains fairly flat dropping substantially below the crossover point, which is essentially what we want here. The span is reduced to about 9 dB (i.e., -74 to -65). The overall volume is also louder.

It is interesting that even though the closed back sounds like it has more bass, the open back must by responding with things/reflections in the room causing more deep bass. I am simply switching between the two speakers and recording the results without any provisions to equalize their volume. What you see is what the mic hears.

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[toddalin]

I have found that while no back is better than having a full back..., having some back can produce a flatter bass response than no back. Therefore, I'll cut both backs down to two strips to go along the bottom to hold the terminal cup, and the top to match, leaving about 31.5 sq in in open. This is also roughly the area of the cone so we'll see how that goes.

Meanwhile, I pulled the back off the other one and have each sitting on an L200/300 cabinet. These are wired with 35 mfd in series with the positive lead to the "B" speaker output though my speaker switcher that allows for volume matching. I actually have these turned down by ~8 dB according to the panel markings.

I'm loving it! If you look at the RTA plots you will see that the 2251Js have a nice little "bump" that fills in the gap left by the crossover between the 2235 and 2420. Then you get a near perfect natural rolloff to the 2405 with no electrial filter necessary! Vocals and cymbols become so much clearer, or there where they weren't before. I should have done this years ago.

Actually, I'm betting that the 2251J could easily replace the 2420/horn all together, go much lower, and would be smoother doing it. May just need to turn off the horns and give this a try.

[toddalin]

Go Big or Go Home!

http://www.audiokarma.org/forums/styles/default/xenforo/smilies/cuernos.gif

Oh wait a minute..., we are at home. Never mind.

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[toddalin]

Work goes on.

Review of the Heil spectrum revels that the "hole" in the midrange associated with the ESS AMT series is due to the fact that the Heils have a natural roll-off well above their crossover point. I find that you really don't want to take the Heils below ~4KHz.

You can't make a driver do what it can't do without compromising the sound, so rather than try to make the Heil reach down to ~2,500 Hz, we will run parallel band pass filters into the 10".

One filter is between ~210 and 4,500 Hz. This protects the woofer at the lower end, brings the ~4K peak down to that a 1K, and meets the Heil on the top end (47 mfd/~0.4mH). Graphic shows a sealed cabinet. I've found that if I port the cabinet, I can increase the low end to make the 210 crossover point.

The other filter is between ~1 and 3.5 kHZ. This will smooth out the dip which looks to be pretty much "1st order." (~6 mfd/~1 mH). Mills resistors will be used to balance the two circuits.

It's time consuming winding coils, substituting lots of cap values, and analyzing and comparing results, but we'll get there.
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[toddalin]

Well, the parallel bandpass filters, coupled with the cabinet port idea works like a charm. This may now be oine of the flattest speakers within its range, which is quite large.


Your crossover will make or break your design.


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[toddalin]

I've been working out the crossover and decided that based on the characteristics of the drivers, the parts on hand, available part values, and costs, I would set the crossover points at 160 Hz from the 2241H to the 2251J, and 3,340 Hz to the Heil AMT. I was trying to work this out to avoid L-pads, but the ear is too sensitive to small changes and readily available discreet components provide too course of changes.


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[toddalin]

https://www.youtube.com/watch?v=bxpa-8U6j_8&amp;feature=youtu.beJBL does Aja.

Stereo SACD

Oppo 95 though Yamaha RX-Z9, both in "pure direct" mode.

JBL 2241 18", 2235 15", 2251 10", 2420 Driver/2312 Horn, 2405 Slot Radiator, Heil AMT.

No digital processing, subwoofers, room correction, or eq added. Room is ~16.5' x 26' with a 7.5' - 15' sloped ceiling.

Recorded on a Nikon D750.



Last edited: A moment ago

[toddalin]

Black Cow


https://www.youtube.com/watch?v=UnWt8iTbVB8&amp;feature=youtu.be

[badman]

I've not seen an issue running the heils below 4k- in fact, one of the best attributes about them is their upper midrange/lower treble capabilities- the folded diaphragm has as much surface area as an 8" (but one with minimal xmax capability). With care they can readily crossover well below traditional domes, in the 1500hz range, or even lower if you can give them the right acoustic environment (a waveguide bumps the bottom end up, I've run them happily at 1300hz and up)

Don't use acoustic rolloff alone, particularly on a compression driver. Excursion increases for most of these drivers faster or as fast as the inherent rolloff of the driver/horn combo, as frequency decreases.

With this many drivers to work with, you might consider a transient-perfect design- duelund described it, possibly others, where a 12dB rolloff on either end of the passband for a mid, with clean 12dB lowpass below and highpass above, and the phase inverted on the mid. You get a nice flat phase response if you can align drivers well.

With respect to open vs. closed back bass, the ultimate enclosure for most mids is a damped line. Basically a TL, but without intending to grab output from the backwave, just damp it. This damps the drivers fs peak and makes crossover work much easier (and more effective at power limiting at Fb vs. a conventional box, unless you include an impedance trap).

You're welcome to drop by, I still do have the multichannel amp and XO you're welcome to borrow as you're working through this. I took two days off thurs 2/15 and fri 2/16, and may have an open house to get rid of gear, if I can get it all tested, photographed, etc., in the next couple days. I want to cash out on a lot of my old efforts and reclaim my garage for the wife's new ride.

[toddalin]

You're welcome to drop by, I still do have the multichannel amp and XO you're welcome to borrow as you're working through this. I took two days off thurs 2/15 and fri 2/16, and may have an open house to get rid of gear, if I can get it all tested, photographed, etc., in the next couple days. I want to cash out on a lot of my old efforts and reclaim my garage for the wife's new ride.

Thanks, looking forward to it.

At this point I've gone all passive. This allows me to use the speakers all together with the L200/300 or in two separate sets. The 18"/10"/Heil is actually about 3 dB lower than the L200/300. I can balance this through my system when used simultaneously, but if I do, the 10" becomes too "present." I have L-pads on the way (currently discreet values), that will allow me to adjust the volume to the 10" and the Heil independently to better dial in the system.

You are welcome to come by and hear this any time. Hey you need a break!

[toddalin]

An update.

I'm still working on the crossovers (very close) and have yet to address the lack of any padding in the 18" cabinet, and to reduce their tuning frequency a bit. Hear you can hear them when compared to the L200/300. I've been trying to get that dark cloud off Joni's voice for years. This seems to do it.


https://www.youtube.com/watch?v=J5g4RVRLCO0&t=2s

[Sootshe]

Great effort......you sure do have some patience......must sound great.

[toddalin]

Today I cut out the faces for the crossovers. These will be stained in black and the white lettering will stand out. Note that the lettering was printed inverse to show through. The pots will get new clear backings with their functions in white.http://www.audioheritage.org/photopost/data//500/medium/DSC_00023.JPG

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