A DAC-off? Kind of funny, I just unwrapped a new DAC this afternoon.

Yeah, come on up, Donnie! Show off your hardware! (er, realized who I was saying this too) Show off your DAC!

You're welcome. The tested and selected from Steve sound as good, another alternative . . . . I've moved to Amperex Holland 6DJ8 in the ZTPRE now .  .  . just a different texture, I'll switch back to the 6N5P in the future.

Palo,
I bought a Grace Design M900 DAC/pre/headphone amp. Just a inexpensive little DAC. It sounds pretty OK so far.
I'm upsampling everything into DSD X2 right now with pretty good luck.
I also discovered that the latest version of JRiver was holding me back by 10 Db because of a setting that I hadn't noticed. I was blaming the DAC, thinking that the output voltage wasn't the 6 volts as advertised. Well I now have the weight and volume that I craved. You have to pay attention to your software settings!
Anyway, things are working out fine down here in the middle of the cornfields.

Greetings Palomino -

First off, thanks for posting so much detail in this thread!

I own a pair of Hawthorne Augie bass drivers, and I'm interested in a project like this.

I spent the entire morning reading, and joined the forum to ask a couple questions (I tried to send a PM but it seems I need a minimum count of 5 posts before I can do that - hence I'm posting here.)

If I understand correctly, you're still using the Tangbang 1808 along with the Dayton AMT, with just a capacitor on the AMT and an inductor on the Tangbang, is that correct?

If so, can you please share the values for the cap and coil that you're using?  It seems the cap may be 25uf?  I saw no info for the coil value.

Thanks in advance!  :)

Thanks Palomino!

I need to gather materials and cut new baffles, so this project will take a little time to implement.

All the info you provided in this thread gives me the confidence to take the plunge on the 1808/AMT combo.

Unfortunately looks like the Betsy WOW driver is no longer available.  But thanks for describing your set up maddog!  I'm really intrigued by the "full-range driver along with an AMT" concept.

My current setup is Hawthorne Sterling Silver duets ... Augie on the bottom, Hawthorne Sterling Silver Iris coaxial on top.  The coaxial is an Eminence 15" driver with a Radian compression driver tweeter.  They make pretty much any recording sound good, but I'd characterize them as relaxed and lacking low-level detail.  Not sure if the lack-of-detail is due to the 15" driver, or the crossover, or both.

My goal is more low level detail, more energetic sound, without being overly clinical (I realize this is very subjective  :) )

Looks like Palomino experimented with the Eminence Alpha 8a as an alternative to the Tangbang.  I wonder if I should consider the 8a.  My Hawthornes use an Eminence 15" driver so I'm concerned that the 8a might not be an improvement.  Still leaning heavily toward the Tangbang for this reason.

jdaun,

I too have a pair of the 15" Hawthorne coaxials and their associated passive xover.  I have the the SI version not the Sterling SI that you have.  And.... when the SI drivers were installed in my Trio's, it sounded as if someone had thrown a blanket over my speakers compared to any full-ranger that I've experimented with.  To say that "life", dynamics and micro detail were MIA with the Hawthorne SI coaxials, is a huge understatement.

Don't assume the Betsy W.O.W. drivers are not available.  Check with Randy in Caintuck.. http://www.caintuckaudio.com/.  He has all the inside scoop on Wild Burro Audio.  I have a pair of the regular Betsy drivers with whizzers too.  For the $$, I would suggest you give them a try.  They are very musical transducers, and will not ever get "in your face" IME.  Most folks likely dismiss the Betsy's because they are so inexpensive.  I guarantee you they punch way above their price point - way above it.  And they possess nearly none of the Lowther shout.  With a Torii 3, and it's treble shunt control, you can control this completely.  However, I run the Torii's treble shunt wide-open (no attenuation) with the Betsy's and also use more "vivid" sounding tubes.  The Betsy's are a bit forgiving (a good thing most of the time).  For $110 - you've not got much to lose.  The Betsy's need some break-in, they will be a bit flat, dull and lifeless sounding out of the box, but they bloom extraordinarily well over about the first 50 hours.

I have also used Audio Nirvana SCF drivers (www.commonsenseaudio.com) with good results.  Fifteen inch ferrite magnet versions and 12 inch Alnico magnet versions.  The ferrite need quite a bit of taming when used in a box, but with the Torii, they are very good in an open baffle.  The Alnico drivers worked great in a big ported box and are notably smoother and softer sounding than the ferrites when used in an OB or a box.

I see that ESS has all 3 sizes of the Heil AMT on sale right now for $140 each ...normally $350 each.  http://esslabsusa.com/heil-amt/

This intrigues me because the smallest size, the "Heil AMT Air-Motion Transformer III" has a much shorter form factor than the Dayton AMTPRO4 (the Heil measures a bit over 3" high x 6" wide), so I could create an adapter plate and fit both the Heil and aTangband 1808 below it, into the 15" cutout in my existing baffles where my Hawthorne coaxials currently reside.

Specs on the Heil website say:

Impedance: 4 ohms, Re: 2.9 ohms
Power: 40 watts RMS, 160 watts max
Response: 1000 Hz – 30 kHz
Sensitivity: 96 dB, 1 watt, 1 meter

Trouble is, I can't find a frequency response graph for the Heil AMT 3 anywhere, so I have no idea how, or if, it could reasonably be crossed over to the Tangband.  

It's 96db efficiency compared to the ~93db of the Tangband implies that an Lpad would probably be required, but beyond that I have no idea.

Nor can I find an impedance chart, the Dayton AMTPRO4 has a flat impedance across the entire frequency spectum, not sure about the Heil.

Anyway, wanted to share in case any of you have curiosity about Heil's AMT offerings.  I sent an email to ESS asking them to supply those graphs, I'll post back if they send them.

Wow, that looks like a great price on the AMT! I don't remember those being available when I researched them a couple years ago. I had a pair of speakers that had original 80s vintage AMT on them, and they sounded pretty amazing.

That looks like an amazing setup for "away from home" listening!

I installed the latest DirectStream OS, so we should have another meet soon!

I'm off all next week too BTW.


I'm surprised you're not streaming from my NAS over cell booster, ya bastard! LOL

Tablesaw is cleared off. I need to polish and wax the top, but beyond that we're set.

I'm off all week if you want to work on them. I'm going to be working in the garage/shop starting tonight. I'm building a new bench for the chopsaw and storage, and trying to fit the FJ in the garage.

Beyond that, I'm open for cutting some pieces for you.

Ok thanks Raven.  I forgot my brother is coming starting tomorrow.  He may go out on his own so I’d have some time.   I am going to do some designing tomorrow.

I got a couple new Clarity cap CSA 25uf capacitors which I think have helped the sound of my speakers.  Clearer, richer and more air.   The one I had before were cheap parts express caps.   These are mid priced but supposed to punch above their weight.  So far so good.

Since I am not using the crown amps for the Auggies right now I am trying to figure out how to combine right and left input from the Rachael and run in bridge mode out to the sub.  Either that or combine left and right out of the crown to the single input of the sub.   Plate amp did that before.

Raven and I were busy on Black Friday.  He helped me build a new pair of experimental baffles.  

We also had a quick listening session to hear his modded ZMA.  It really sounded outstanding and perhaps the best I have heard his system/room sound (without room treatments BTW – he is remodeling).  Big open sound.  Room filling.  Some impressive bass too but that may have been the Direct Stream update.

Anyway, I had three things I was trying to accomplish with the new baffles:

1.  Bring the AMT down closer to ear level (it was kind of tacked on the top of my old baffles).  Randy had advised me that these drivers don’t have the best vertical dispersion.

2.  Open up the soundstage.  I felt that the large baffles were blocking information from getting back to me at the listening position.   Also, this blocking was keeping some instruments on certain songs glued to the speaker and ruining the illusion.

3. Make some baffles out of Baltic birch.  I have heard a couple of pairs of speakers made from baltic and they sounded faster to me.  I like the tone of the ply versus MDF.

The whole idea of the stepped baffle shape is to have as little baffle as possible for each driver in order to allows as much sound to come around the baffles.  This shape is probably not everyone's cup of tea, but the proof is in how they sound.

I took the wood to Raven’s place for precision cutting.  As usual, his big saw cut through it like butta.  We did have to do some work with the cross-cutting against the grain using a band saw and even a jig saw.  

We probably wouldn’t have needed to use the latter two saws if we’d cut against the grain first.  Raven saw how it could be dangerous to cut against the grain after we had already done the with the grain.  Nobody wants a chunk of wood in the face.  Anyway, it was no big deal as Raven has a steady hand and I had to do very little sanding afterwards to true everything up.

I cut the driver holes back at home and glued it up and attached the stand hardware.  

I listened last night and was pretty impressed.  A little more detail coming through via better on axis with the AMT but the big gain was on the openness of the soundstage.  A lot was being blocked by the big baffles.  The Baltic seems a little more lively as well.  Some help with the instruments glued to the speaker phenomenon.

Some pics:

QRD7 (outside) and QRD13 (inside running vertical and top running horizontal).

The black ones running horizontal on top of the outside QRD7s are purchased painted foam fractals.

The QRD7 are made from the cheapest plywood I could find at Menards, poplar and slotboard (pre-routed board for the fins).

The QRD13 running horizontal is MDF with some kind of subflooring material for the fins.  It was a prototype that worked and I kept it.

The vertical QRD13s are made of Baltic birch and I am somewhat proud of the build.

I typically slap black paint on everything to hide my shoddy wood/glueing work.  They all work though.

I also have QRD23s on the sides (not shown) made from poplar, 1" insulation foam and subfloor material (it is pretty straight and works for fins).  These are my best diffusers.

The rear wall has 5 fractals hung on the wall and two more QRD (both experimental prototypes).

Raven got me going and I can't stop.

It was a good quick listening session - and Pal, since I was having issues with the DirectStream volume, we were listening to the TEAC. So just imagine how that's going to sound once I get the DS sorted out!  

It was TEAC via XLR to 25th Modded ZMA with Mullard CV2492 input tubes, and the KT8C output tubes to the unfinished El Camino speakers.

It was some good sound!

Once Bad Wolf get's his 25th Anniversary Zen, we'll definitely have to have a CDApS meet!  See if we can get some other locals to join us maybe?

Ha!  As you know too well, lots of time goes into these.

Randy, I noticed you use ply or hardwood.  Do you think they sound "different than MDF?  To me, MDF does not sound as lively.

BTW Randy, I have a whole new appreciation for your work on the Betsy Baffles.  Cutting cross grain can produce some splintering!

Thanks Show.  

I do intend to put a finish on them but that will probably wait until Christmas break.   I won't have time till then but also I don't know if I want to endure the downtime.  I spent about 4 hours last night listening to my playlists and everything sounded really good.

Donnie,

After seeing your build I did my big blackies with tweeter and mid offset from the woofer.  I thought about doing that on this pair, but wanted to see how everything lined up sounded.

We'll just have Bad Wolf's 25th at the official December CDApS meeting, assuming his is finished.  I'll have to check the build list but I think parts were being pulled or it was on bench last time I looked.

Quote:


Hi Palomino,

I know that veneer covered MDF is a mainstay of the "box" speaker industry, but I have never made a pair of Betsy baffles from that material.  I know that it's heavy .....  

Of all the baffles I have made, I hear a slight difference between Baltic birch and all of the other plywoods used.  As you know, the construction of BB is unique.  It sounds a little more detailed and "tighter" to me than the other plywoods ..... which sound a little "warmer" to my ears.

As to the hardwoods, most of them sound pretty much the same to me with the exception of Bubinga (African rosewood) and Purpleheart.
With a revealing front end and amplifier, these two hardwoods definitely have a more detailed and controlled sound than the other hardwoods I have used.

I'm presuming that it has something to do with the density and weight of these woods .....

It is apparent when picking up a baffle made from one of these hardwoods that they are "heavyweights" .....

Once again, your baffles turned out very nicely ..... well done !!!

Happy listening,
Randy

Today's project was to flare the driver hole in back for the Tang Band.  I am telling myself it did some good.

Are you going to do any wind tunnel testing?  

Any word from AA about his 25th yet?

That looks really nice and smooth! How much of that was router, and how much was sanding, sanding, sanding?  LOL

I've almost got the FJ out of the garage, so I hope to be back to woodworking this next weekend! YEY!