The German folks selling tractrix horns for Altec drivers on eBay are on summer holiday. Does anyone know of a source of something similar to play with? I've come up dry in a couple of days of googling. Thanks!
taudo
Printable View
The German folks selling tractrix horns for Altec drivers on eBay are on summer holiday. Does anyone know of a source of something similar to play with? I've come up dry in a couple of days of googling. Thanks!
taudo
Yeah, it's called DIY.
GM
GM,
Care to expand on that? I came across about a half dozen different DIY methods and really don't care to try them all. [Frankly, I'd rather buy a pair, if anyone knows of a source]
taudo
GM,
Thanks for those links! It appears that Sierra-Brooks has already done the experiment I wanted to try and made a commercial product out of it. I love the look of those 32" horns - but suspect that if I drop $3500 on pair of them for an experiment, I'll be exiled to the barn!
Given that Avantgarde, Galix, Acapella and others are all advertising speaker systems with similar looking plastic horns, I'll bet there is some OEM turning them out by the boatload.
taudo
What's to elaborate on? I mean all you need to know is on the net. This site is just one of many: http://www.volvotreter.de/ so if you need further clarification on something, you will have to ask specific questions.
WRT different ways to make them, either carving them from a solid block of wood on a lathe or casting them in concrete is the ideal, but two flat sides and two curved sides made from 3/4" 13 ply BB or Appleply works well also. FWIW, I prefer conical over tractix for loading compression drivers, but the tradeoff for the lowest distortion/better off axis response is an increase in size for the same usable BW.
http://www.sierra-brooks.com/
GM
Mike,
Thanks for that input - it appears to be just what I found with the exception of the above mentioned German folks who _were_ selling inexpensive plastic or resin tractrix horns specifically for Altec drivers. I hope they decide to sell 'em again after the "summer break".
If worst comes to worst, I may try building one up using the "concentric rings of wood" method.
Thanks!
taudo
I guess I wasn't clear enough the first time, the sonic difference between a round and square version using a 800 series CD is so minor that I can't justify the extra work required to make it round unless you just want it round for round's sake. The only caveat is that the square throat must be smoothed/tapered to a round termination, which is easily done with Bondo or similar and the mouth be a square equivalent to the round horn's diameter instead of the 1WL circumference rule.
If you want to further reduce any possibly perceived difference, then shape a small Bondo applicator to make a rounded corner and fill/round off the internal joints. This has the advantage of covering up the gaps when simple joinery is used by lazy woodworkers like me.
A point rarely mentioned is the need for a non-porous, slick surface to ensure good performance since wave propogation is moving back n' forth at ~13,560"/sec, so using a good sealer and waxing it with racer's wax or similar polymer is required if made from wood, though the 511/811s benefit from it also, especially so if all the usual tweaks are done.
GM
I looked into this a couple of years ago when I rebuilt my Model-15's. I wasn't DIS-satisfied with the horn on the Model-15, but I had heard so much about the tractrix horns that I looked into them.
Most if not ALL the production tractrix horns that you can buy are made of these exotic hand carved woods that I just couldn't justify the experiement. Companies like Klipsch use Tractrix horns which are made of some polymer or resin. But as far as I know they don't have one for the Altec 800 or 900 series compression drivers.
taudo
I saw those horns also on Ebay. Do you remember which models you were looking at??? They seem to offer a few different models for the 800 series. I didn't know what the differences are between the different models.
Let me know if you do end up getting them. I'd be very curious as to what the sound expereince would be like. Maybe I'll rebuild my 15's AGAIN...Oh my wife will really love that.
they basically have three models one with a >1000 cut off one with a >400 cut off and another with a >180 cut off, you can order with different driver sizes 1"-2"...you can see them on ebay now; http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW
or visit the web site;
http://www.stereo-lab.de/
I have no relation with the sellers nor have tried these horns,
best of luck, tony
Yup, those are the ones.
I was kind of surprised to see them back on the bay so soon as they had told me just a few weeks ago that they were off on summer holiday. Nonetheless, I'm glad to see it.
I've ordered a pair of the 1"/400 Hz horns and will play with them using an extra set of 800 Altec drivers I have laying around. I expect them to be somewhat "beamy", but who knows.
I'll post a report here when I can. Thanks for the feedback!
taudo
Taudo, Was that you? I could not find any ID on the email. Thank you for sending that email. I was interested until I just blew my wad on a pair of 1005Bs with two 288c on each one. Just by chance, the guy I bought the 1005 from has 16 2245s he got from an Alabama tour so I reserved two of his. Cheers.
>1"/400 Hz horns
====
Hmm, can't find any dims, but assuming they're a typical tractrix design, these should only load to ~566Hz so you need to take this into account when choosing the XO point/slope.
GM
GM,
I plan on crossing them over at 800+ in any event - so as to compare them to my Altecs. That active crossover with its infinitely variable crossover points sure makes that a breeze!
taudo
Igor,
Yup, that was me. 'Sorry that it arrived anonymously!
So, your source has _14_ 2245's left? I think we could make some serious bass with those!
taudo
my diy attempt: http://home.tu-clausthal.de/~tpa/VotT/index.html
tilpape,
I came across your website earlier while looking for horns, and was very impressed! I even printed out a copy to add to my "scrapbook". I think you may have the answer for diy-ing the MR wood horns in 825/828 enclosures. If I get crazy enough to build another set, I think I'll try your method.
Thanks - and glad to see you here!
taudo
Taudo, if you don't mind, how much did you give for them and how much of that was shipping? Thanks.
Igor,
Actually, I'm still waiting for the exact figures, but the horns are $221/pr [179 euros] and shipping was initially quoted at about 30 euros. So, for about $300 US, I'll have a couple of tractrixes to play with.
[But I'm still lusting after those Le Grand 32 inchers!!]
taudo
BTW, did you get my private message about the 2245's?
A pair of 1" 400 Hz tractrix horns from the German firm of Stereo-Lab.de arrived at my door last night. They appear very well made, constructed from about a quarter inch thick, dense acrylic/resin or somesuch. Very nonresonant. They're finished nicely in a black crinkle-finish - but come in a range of colors. They are about 11.25 inches across the mouth, and about 11 inches from mouth to mounting flange (perhaps someone here has the equations to analyse these dims)
I had only a few minutes to give a quick listen, but initial impressions are favorable. The dispersion seems to be about 60 degrees, with fairly rapid fall-off outside that. I would describe their sound as quite bright and forward when compared to my 511's. I used just GPA'd 802's for my quick test.
I bought these to experiment with - and they appear to be very good material with which to do so. They cost only about $260 with shipping and took a bit over a week to arrive. You can't beat it!
taudo
Taudo,
Let me know how they are when you give them a long(er) test. I'm very interested. I do like the horns on my model-15's, but would like to hear about how the tractrix design works with the 802 (i have the 802-8g). From what I've heard they should sound GREAT.
They sound best on conical if a 1 kHz XO is acceptable.
GM
Taudo
It looks great. Don?t forget to report your listening test.
It let me remember to the Zingali wooden horns.
HiFiPlayer
Hi, tillpape
There is a great homepage. I appreciate to your ideas.
BTW, Is it yours completed plan?
my opinions are :
1. to reduce the opening mouth size can makes the bass flat down to 32Hz, 2H x 12W. Of coz, 828 cab?s inside also need some modification.
2. though TAD 1601a mounted on 828 cab can provide deepen bass than the Altec 515s, but as I known that 1601a just has 97db.
Anyway, it stills a great job that I?ve ever seen.
Just a lot of blah. http://www.hostboard.com/forums/
HiFiPlayer
Just for fun.
To beware some tractrix horns reproduce sounds as battle signals ?Woooooo? when playing music http://www.hostboard.com/forums/
HiFiPlayer
-----------
as simple as best
Taudo
Will you consider to adding horn lens? I think it can improve to the diffuseness.
HiFiPlayer
-----------
as simple as best
GM,
> They sound best on conical if a 1 kHz XO is acceptable
====
Just so happens that's exactly where I have them XO'd!
taudo
MikeinNH,
> Let me know how they are when you give them a long(er) test.
=====
Will do, Mike. Unfortunately I've got only one day off in 9 or so - it will be Sunday before I can even listen to them again.
This working sure interferes with one's hobbies!
taudo
HiFiPlayer,
> Will you consider to adding horn lens?
====
I'll demonstrate my ignorance (once again!)and admit that I don't know what you mean. Please explain. Thanks!
taudo
Taudo
Round horn mouth would provide round diffuseness as fulgurite lightening. So I think add a lens will get some improvement.
HiFiPlayer
----------
as simple as best
Taudo
Have you ever seen some vintage model of JBL? The one that mounted on the front of the horn open mouth looks like an engine?s heat sink.
i.e. JBL 175, 275, 375, 376 and also Hartsfield.
HiFiPlayer
----------
as simple as best
HiFiPlayer,
I remember seeing a vintage JBL horn that had a number of plates on the front, each looking something like the letter "W", and angled down at about 45 degrees. Is that what you are talking about?
taudo
Taudo
Yes, that is. It helps for the wave diffuse. Usually made of plastic or aluminum. you can try to replica one with wood if you like. It also makes your horn becomes smart. I have seen some of online shops selling so cheap.
Other kind of JBL made looks as round potato masher, place it on speaker top would light up your nostalgic moods. http://www.hostboard.com/forums/
HiFiPlayer
------------
as simple as best
Arrrggg!
I haven't had time to play with the Stereo-Lab tractrixes yet, then this shows up on eBay! http://www.hostboard.com/forums/
http://cgi.ebay.com/ws/eBayISAPI.dll...720310910&rd=1
taudo
And, just to add insult to injury, I stumble across this:
http://www.diy-systems.com/
It ain't fair, I tell ya!
taudo
It seems has its own sound characters but anyway, I still believe that Altec is unbeatable in my experiences.
A fresh one doesn?t mean as better?right? http://www.hostboard.com/forums/
HFP
---
as simple as best
Hi - if anyone is interested, I build solid hardwood hors replicated from Altec 311, 511, 811, JBL 2397 and Westlakes as well. I can be contacted at [email protected] and would be happy to send anyone interested some pictures of my work. Kind Regards, Dean
For those of you who may be interested, I wanted to update my experiences with the tractrix horns from Stereo-Lab in Germany. These horns are sometimes seen on the English language version of eBay [where I got mine] and are apparently always available from the company?s German-language eBay store. These horns are promoted as being for Altec 1? drivers [although I imagine that any 1?, two bolt compression driver would work]. There are also versions for 1.4? and 2? throats. They are also available in several sizes corresponding to different lower frequency limits. The ones I bought were the 1? 400 Hz design.
Before I tell you more about my evaluation of these horns, I have to make a disclaimer of sorts. I bought my first set of 802/811B?s some 33 years ago. I have been listening to Altec systems for most of that time - and loving them! Therefore, I think that the ?Altec sound? of the 800 series drivers coupled to 811?s or 511?s is etched rather deeply into my auditory system and serves as a reference for me - with all their imperfections. I judge everything else I hear in relation to that standard - a sound all of you on this board are well acquainted with. To me, the sound of the aluminum horns is ?bell-like? and very pleasant. I?m well aware that others would say I?m nuts, but there you have it.
With that said, I have now had a number of listening days in which I compared my 511B?s to the Stereo-Lab tractixes. My 511?s are the later model with the RTV in the vanes. I have them mated to 802 drivers that have just been redone at Great Plains Audio. The have the aluminum diaphragms in them. They sit atop my 828 cabinets that have 416 midranges, 2235 woofers, and all the recommended mods. I drive them with a tri-amped setup consisting of a Rane AC23B and a trio of Hafler rack-mount amps, the HF amp being a P1500. I?ve found that I like to set the HF crossover frequency at 1 kHz rather than lower. To compare the horns, I simply switched out the 511?s with the tractrixes, leaving everything else just the same. It should also be noted that I like to listen at very moderate volumes, so I cannot comment on how these horns would sound at 100 dB.
One of the initial tests I did was to switch only one of the horns, giving a comparison of the 511 on one channel and the tractrix on the other. This is what lead me to initially characterize the tractrixes as ?bright? and ?forward?. I think this was a byproduct of the tractrix?s narrower angle of dispersion and not at all what I would say now. I listened to a bunch of my favorite music with the 511?s in place, then switched both horns and played it all again. I think this is a better test, and what my current comments are based upon.
As I mentioned in that earlier post, I had expected the tractrixes to be beamy and somewhat megaphone-like in character. I was pleasantly surprised on both accounts. The angle of dispersion seems to be about 60 degrees and very uniform within that angle. It falls off fairly rapidly outside that 60 degree cone, but 60 degrees is plenty for home use. There is not the slightest hint of a ?megaphone? coloration to these horns.
In fact, a lack of coloration is probably the single biggest thing about these tractrixes. The ?bell-like? quality of the metal horns - that I like and which others hate - was completely gone. The resinous material of the tractrixes is completely nonresonant and seems to have little coloration at all. If anything, I would characterize them as nonresonant in something like the way MDF is nonresonant. The result was that the tractrixes seemed to ?blend? with the sound of paper woofers and MDF boxes much better than the 511?s. After a bit, it seemed that the 416?s and the tractrixes subjectively blended together and it became more difficult to tell which driver a sound was coming from.
For those of you who don?t like the ?ringing? coloration of the Altec aluminum horns - here is a possible answer for you. Certainly, the difference in coloration was the biggest thing I noticed in my listening.
The tractrixes also seemed somewhat more defined or articulate than the 511?s. There seemed to be a sharper line between instruments and tonalities. Perhaps this is what the pundits call ?etched? - the word does seem somehow appropriate. Again, because I?m so accustomed to the Altec horns, I found this quality to be just slightly unpleasant, but I can easily see how another might find this a very attractive quality. Certainly, it seems to increase the lines definition.
Stereo imaging was excellent. It seemed that images between the speakers were smaller and more localized than with the 511?s. The ?soundstage? projected seemed a bit narrower also, but was satisfyingly deep and surprisingly ?high?. By this, I mean that some images seemed to be projected closer to the ceiling by a little bit. Perhaps this is a consequence of the 20 degrees or so of increased vertical dispersion that the tractrixes have. In any event, it was interesting.
All in all, I found the Stereo Lab tractrix horns to be very good, indeed. Another purchaser left feedback that he liked them better than the much more expensive Brooks-Sierra horns - so I assume he made that direct comparison. The Stereo-Labs horns? lack of coloration is excellent, and their dispersion very good. They are also quite small when compared to other horns - a little under a foot in diameter. I would certainly recommend them to anyone who just hates the ringing of Altec horns, or who needs a small horn with big performance. I purchased them with such a project in mind and I think they will excel in that use.
They will not replace the 511?s atop my 828?s, however.
taudo