Info about Avalon clone project

**JonMarsh** · 05 November 2002, 17:33 Tuesday

Yes, this is a fun thread!

The woofer is an Eton 11-581.

The mid is an Accuton C79.

The tweeter is an Accuton C12-6 (in the standard Eidelon).

Personal opinion ON:
Warning: Neil Patel often engages in somewhat colorful prose which borders on hyperbole to describe the technology behind current Avalon models.
Personal opinon OFF

With regards to the claims for comparable transient response with the ported system as the older sealed Q of 0.5 (critically damped) Avalon systems, I have to say, No Way Jose.

However, with the right techniques, one can make a ported system with extended output capability over the sealed system, and render it very clean and tight "sounding". The specific tuning of the cabinet alignment and damping is quite important; as with the M8 bookshelf, a slightly overdamped alighment due to the driver characteristics, box size, and acoustical damping works well. Additionally, when Niel refers to electrical networks, this is using a conjugate zobel to neutralize the impedance rise of the speaker and make it look like a resistive load externally. This provides a measure of damping independent of the power amplifier (and it's feedback loop, if present). This does sound better, but requires large inductors and capacitors, though they don't have to be low resistance (since there's an explicit resistor anyway in an LCR network).

Still, I think think that with the swept Sd and intended output of the 11-581 (or two M8a's), a four inch port is a better choice than a three inch. The M8 bookshelf uses a flared three inch port. The smaller bookshelf's I've done (with 7" Scanspeak drivers) used 2-1/2" ports.

The rest of the "solidity" and impact in the bottom end comes from having enclosure walls that don't talk or flex.

I agree with Dennis that laminating 3/4" MDF with 1/2" particle board seems like a rather odd choice. My first reaction is why not two layers of MDF, or a layer of MDF and baltic birch ply, for example.

Still, it's good taste in his choice of speaker to emulate!

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**JonMarsh** · 21 February 2003, 17:59 Friday

Time passes, but the idea of Avalon Klone's hasn't died.

Trond-Eirik shared his concept for a Avalon monitor klone, based on a re-working of the M8 design, and we've worked on an AutoCAD drawing (he started, I tweaked) which I think has turned out pretty nicely. It's certainly a bit neater looking than the "plain old boxes" I've built, and I think they're be pretty cool to see when built.

With the planned box size, the internal working volume will be about 39 liters. With a moderate port length, fairly good LF extension is possible-

With the Avalon style grilles planned, they'll look pretty classy....

But I think they look pretty cool even without the grills... :B

This project of Trond-Eirik's continues to tickle my fancy- to the extent that a floor standing M8ta is on the drawing board- or rather, in AutoCAD.... :W

-Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Andrew Pratt** · 21 February 2003, 21:07 Friday

Jon I see the XT25 is no longer off centre and the baffle is now different...what effects on the XO does that have?

**JonMarsh** · 22 February 2003, 11:45 Saturday

The mirror image off center location used for the box M8's is deisrable/necessary to distribute the edge diffraction effects over a wide a range of frequencies as possible (which reduces the amplitude at any one frequency), so that combined with the suggested front panel damping with soft felt, edge diffraction can be minimized in the on axis response, as well as off axis.

The Avalon style faceted baffle design was something Bill Kennedy and I first tried out in the late 70s, and it greatly reduces baffle diffraction edge effects, and and also distributes them over a wide range of frquencies. However, it has some other complex behaviors- reducing the baffle support in the lower range of the tweeter above the design axis, while maintaining strong response in the lower part of the tweeter range on the main forward axis and slightly below it. The actaul crossover of the M8 should require little or no modification with this different cabinet, maybe a slight adjustment in the balance of the low range of the tweeter to the upper range, but possibly not.

I gave one of our early larger systems (actually a double 10" four way) to Charles Hansen in '84- (Charles used to work for me when he was a physic student at CU) those cabinets used constrained damping multi-layer construction as well as a faceted construction.

The biggest "disadvantage" to these type of cabinet construction, of course, is that they're much harder to build then ordinary boxes, seeing as there aren't hardly any 90 degree angle cuts.... and the veneering if you want a pretty version is not trivial.... :roll: There's a ton of work in an Avalon speaker... but then, skilled DIY is about substituting "sweat equity" for bucks, so with the right skills and tools, it's an interesting proposition.

The tower version of this design which I'm playing with in bits and bytes right now will still have basically the same crossover, but will be about 40-42" tall, have a bottom firing port, a tripodal spiked floor support, an internal volume of about 65 liters, and be tuned for about 23 Hz. They'll way about a hundred pounds each, as the laminated up front panel (prior to cuting) is 4" thick. Needless to say, this is about as far as the M8 concept can be taken! Oh, and the one's I build for myself will use Hales Transcendence tweeters, an aluminum dome long travel tweeter which by a wonderful quirk of fate has about the same nominal impedance as the Vifa XT25, and the same resonant frequency- so, very minimal xover mods.

This cabinet tuning combination should result in a smooth slope in the response between about 100Hz and 22 Hz of 6 dB, which with proper positioning and normal room gain, should put it close to flat in room at 22-23 Hz. 8) Still, it's only an 8" driver, so a single cabinet is limited to about 100 dB output in the LF range (25 - 50 Hz). Double that for a stereo pair. In comparison, a smaller boxed M8 tuned to 32 Hz will output more max SPL above 40 Hz. (Higher output on rock and roll, hootchi koo!)

But that only requires 25 watts per channel to hit. So a 100 to 150 watt amp should do quite nicely as a full range system with plenty of transient head room in the upper range- just as for the standard M8.

Calculated M8ta Tower LF response

When I get the tower drawing finished, I'll post some pics in case anyone's curious. For me, this tower project will probably be my "bed in and learning" project for when I get a new saw (originally planned for Xmas, delayed by my back. Maybe late March?)

Best regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Kevin U** · 23 February 2003, 13:48 Sunday

Jon,

consider me one of the "curious". I've always thought the Avalon cabinets are very handsome.

You are certainly right, the Avalon style of cabinets will require alot of work, especially veneering. Lots of opportunity for mistakes.

Kevin

**JonMarsh** · 23 February 2003, 14:42 Sunday

You are certainly right, the Avalon style of cabinets will require alot of work, especially veneering. Lots of opportunity for mistakes.

No kidding! But mistakes endured and fixed = experience. :LOL:

I've been putting a lot of thought and notes into how I'll go about this, and fortunately I've had a couple of personal tours of the Avalon factory in the old days when in was in Charles Hansen's hands. That experience yields some useful clues and insights... :W

At least I'm doing something relatively "simple", unlike their top of the line system, which would be a major nightmare to build!

-Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**JonMarsh** · 24 February 2003, 01:40 Monday

In the spirit of baby steps before falling on your butt, here are the
renderings of the cabinet design I've decided on, which conforms to the volume and tuning above.

What I'm not decided on yet is the veneer- I keep going back and forth between doing something sort of conservative, like birdseye maple (a real Avalon "classic")

and something a little more flamboyant, like Tibor's M8 MTM's, which I really liked in appearance, using Zebrawood.

My long time favorite, which of course makes me feel guilty, is roswood; a good Santos Brazilian rosewood would be lovely....

Veneer images are courtesy of http://www.tapease.com.

Now, here's the surprise- the maple in a good two ply veneer would be about twice the cost of the other two. :E

Another possiblity, teak, flat cut or quartered, would be half yet of the Zebrawood or Rosewood. (less than $200 for two 4X8 sheets.)

Decisions, decisions.... :W

Best regards.

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Brian Bunge** · 24 February 2003, 22:21 Monday

Jon,

Might I specifically recommend the NBL style veneer from Tape-Ease? I've used it and some of the paperbacked stuff and I feel that the quality is definitely above and beyond that of the paperbacked.

**PMazz** · 25 February 2003, 08:23 Tuesday

I too really like the NBL veneers, but maybe not for this project. There are quite a few edges that would give you that tell-tale look that the thick veneers give on an edge. If you want it to look like a single block of wood, I'd use the thin stuff. You may be able to get away with just folding over some of the facets with thin veneer, depending on the species.

Pete

**JonMarsh** · 25 February 2003, 11:54 Tuesday

Interseting inputs from both of you. My inclination was to try the NBL veneers also. I've been trying to figure out (in my head) the best order for veneering to minimize problems with the edges; if they aren't quite perfect, then they aren't quite perfect. I really didn't want to use paper backed veneer, because of the typical difficulaties with them. I'll probably give Chas a call and see if I can prod his memory about what they used at Avalon when he was there! I suppose that may also influence my choice of which veneer to use. Thomas is still badgering me about cherry, so I'm taking a second look at the types available, though I think on a big cabinet a more figured veneer like the zebrawood would be more interesting.

Best regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Tibor** · 26 February 2003, 18:54 Wednesday

8) Hi Guys

Well where talking about veneers okay let me add my 2 Cents .

First no waterbased glue , second let the veneer acclamate to the room and to the climate .
I used paperpack Zebrawood veneer reason more stable and the less chance of the glue bleeding out .
I let the veneer acclamate to the shop or room then cut it to rough size , 2 coats of glue on the MDF 1 coat on the veneer .
The I glued the pieces toghter , used a roller and got out air bubbles. Then used a plastic wallpapper scraper to smooth out the veneer . The it sat in the shop for about 3 to 4 days to dry and the glue to set up fully . The got sanded and finished .
Most veneers are presanded so go easy on sanding 120 to 150 should be it nice and easy . The 3 coats of sealer 1 coat lacquer and let it sit for 1 to 2 days so it can harden .
Rosewood and someother exotic woods give off oils sometimes hard to finish must take special care when finishing .
Some Veneers you can do tight bends with others you can all has to do with the way they are cut and what spices it is .
Remember wood do get darker with time cherry and oka and many others will go dark .
Thats it guys take care .
Tibor

P>S working on the cennter channel for the MTM8 " Suber Size" :LOL:

Well hope that gave some more info

**JonMarsh** · 26 February 2003, 23:41 Wednesday

Thanks for the hints and tips, Tibor. I'm familiar with how teak doesn't take to a lacquer finish, better with an oil type finish. Rosewood I've usually seen lacquered, though I've been curious about trying out some other things on a small swatch. I've used clear Watco in multiple coats with very fine sandpaper (like Hank's methods) with very good results on Walnut and Oak, but I don't know if it would work on something like Zebrawood or Rosewood- any comments from you about what zebrawood is like? Is it fairly hard, or a bit softer than teak or rosewood? I like how your MTM's turned out, so I'm really trying to figure out whether to go with Rosewood or Zebrawood. I was a big Rosewood fan in the 70's, but maybe it's time to "move on". :W

Any additional opinions or tips would be welcome!

-Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Brian Bunge** · 27 February 2003, 01:51 Thursday

Jon,

Hank used the Watco oil finish on his rosewood towers, so I assume it's ok to do. I haven't tried it myself yet.

Brian

**PMazz** · 27 February 2003, 07:52 Thursday

Regarding finishes, remember we're only talking about veneer. Veneer doesn't retain enough natural oils to really cause problems. Solid wood, on the other hand......

Pete

**Hank** · 27 February 2003, 08:22 Thursday

Jon, my method that I e-mailed to you (Danish oil) is what I've used mainly on rosewood veneers. Brian has seen my rosewood towers in person and liked them. Enough hours invested equals a smooth finish that is almost glossy, but obviously is not a cheapo polyurethane - it has *depth* and richness. The advice on letting veneer acclimate is good, as well as letting it sit for a couple of days after appying it to the cabinets. A cabinet maker said that contact cement takes two days to reach maximum strength.

**JonMarsh** · 27 February 2003, 12:00 Thursday

The aclimating recommendations and "setting time" for contact cement jib with my own experience. Heck, I let "fast dry" paint on the cabinet backs and fronts set two days before I do any more work on them! There's a big difference in hardness and finish durability.

I'm also considering a homemade clamping press and more conventional glues (alphiatic resin) instead of contact cement- I did this in the 70's for some stuff- though I've not had problems with the good, nasty industrial grades of contact cements in years past. Avalon doesn't use contact cement, but uses clamping presses instead. Any comments or experience going that way?

And thanks for the reminder that you did your rosewood stuff with the Danish oil method!

Best regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**Tibor** · 27 February 2003, 13:42 Thursday

"Any comments from you about what zebrawood is like?"

I would say its not hard or soft it sand very nicely and takes finish great . When you finish Zebrawood you can see they Sealer just being soaked up by the veneer . Zebrawood is porous .

.
" Is it fairly hard, or a bit softer than teak or rosewood?"
Teak is hard and so is Rosewood

Well if I am building my first DIY Speakers they will not be like anything you can buy in the Store . I was going to go with
Rosewood but I liked the Zebrawood ,and the price was right .
I look at my MTM's like they where furniture pieces .
Tibor

**Pete** · 27 February 2003, 19:25 Thursday

Jon

How about doing the glue & iron way, a few coats of glue let dry
and iron with some cloth down first. This way you can cut the pieces to size hold in place and iron. Just another way to consider.
-Pete

**lbkwhitney** · 21 July 2016, 05:31 Thursday

Hi Jon. I just discovered this site an hour ago and joined. I really don't know how to manuever the site yet it so please pardon my intrusion.

I joined to find if there are ways that I can replace the original tweeters on my Avalon Radian HCs. I know that the original MB Quart tweeters are not available

I have heard that Avalon has some ceramic tweeters from the Idea that they can install. Good Idea?

I love these speakers - bought them new in 1997 - and wish to preserve them 'till the bitter end.

I have reserved one of the packing crates for use as my coffin. Avalon seems to have no interest in preserving these old speakers, so any suggestions for preservation will be very much appreciated

I promise to learn the proper way to communicate on this website.

Best regards,
Larry Whitney

**JonMarsh** · 21 July 2016, 09:06 Thursday

HI Larry,

To the best of my knowledge, the original Avalon Radian HD used a metal dome version of this MB quart tweeter. In some senses you're lucky, because it's a three way system, and the demands on the tweeter aren't all that heavy- my suggestion frankly is that if Avalon has a replacement that is form factor compatible, change out both tweeters is a good idea. The Avalon Idea does use a Ceramic tweeter in this form factor, and if the impedance curve and sensitivity are compatible (I presume they are since Avalon is recommending them) then I would urge "going for it" before those tweeters are no longer available.

There could be a variety of tweeters that are electrically and acoustically compatible, especially for a three way (narrower frequency range), the problem is the unusual faceplate format of those tweeters. Replacing round tweeters isn't usually too hard; many use very similar sized faceplate diameters, and if needed, it's not hard to open up an existing tweeter rebate hole with a router (if you're skilled in the arts, so to speak). But a rounded corner square faceplate makes things very, very specific.

**Renron** · 30 July 2016, 12:02 Saturday

Whoa, talk about Necro posting...........13.5 years has to be a record! Damn!
Welcome to the Nut house LBK. Great group of guys here.
I just read this thread, I hadn't realized that TEK was the trouble maker all along. I'll blame him. Manning too, just 'cause. :W
Ron

**Steve Manning** · 30 July 2016, 13:25 Saturday

Originally posted by Renron

Whoa, talk about Necro posting...........13.5 years has to be a record! Damn!
Welcome to the Nut house LBK. Great group of guys here.
I just read this thread, I hadn't realized that TEK was the trouble maker all along. I'll blame him. Manning too, just 'cause. :W
Ron

Why thank you Ron ...... I feel honored :B

**TEK** · 30 July 2016, 20:57 Saturday

Originally posted by Renron

Whoa, talk about Necro posting...........13.5 years has to be a record! Damn!
Welcome to the Nut house LBK. Great group of guys here.
I just read this thread, I hadn't realized that TEK was the trouble maker all along. I'll blame him. Manning too, just 'cause. :W
Ron

Jup - I'm the one to blame. Check out the intro to this M8t thread... http://www.htguide.com/forum/showthr...a-Fun-or-Work-)
I think that was the first "Jon Avalon inspiered build" on this site - triggered by those initial questions. Now, as you probably know, it took 13 years before I actual got my "Avalon inspiered" speakers completed ;-)

**Renron** · 01 August 2016, 13:24 Monday

Tek,
if that's the case then I'm in no rush.

Your Welcome Steve.

Info about Avalon clone project

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