Bottlehead Forum
Other Gear => Speakers => Topic started by: xcortes on August 25, 2012, 11:35:31 AM
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A "reprint" from my post at the HE forum:
he WE 755As are the most amazing speakers I've ever heard. They are not extended. They don't play loud. They struggle with complicated music (more later). Yet they suck you into the music and transmit you its soul.
I set up a pair in 2 cu ft boxes with 2A3 amps. Cheap Monster cable between them. Quoting my friend: "Even if you play complicated music through them they are so intelligent that they extract the part they can play well". And they excel at doing so. No, you don't hear every instrument from a symphonic. But you get the spirit from it and you get the composer's.
JSB's cello sonatas through these speakers have been the grandest audio (and probably musical too) experience in my life.
I may try 300Bs and see if I can get an extra couple dBs. And OBs at some point in time.
If I had to choose between my tetra-amped horns with field coils RCAs on the middle and Ionovacs on top and the WEs... Well, I don't so who cares.
These paging, cheap, elevator speakers live to its fame.
For disclosure: No, I'm not a WE speakers dealer. Just a (very) satisfied customer. Oh, and of course this is just my opinion and yours may differ.
Saludos
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The last 24 hours my spirit has been struggling after a very interesting listening session. I concluded I enjoy the WEs more than the horn system. I guess simplicity has its benefits. I am about to put the big horns in storage. Along with the karlsons, three pairs of Paramounts, the restored tube rca power supply, etc, etc. Nope I have no plans to get rid of such system. I'm sure at some point in my life I will get the system back together. But right now I'm switching to the WEs. They are that good.
As for amplification I have an unbuilt Paramour 2 set along with Co opts and Co plate chokes, grid chokes and I think I will go overboard with caps, wire, etc. Easier to do when its one pair vs three. Stay tuned
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Aren't you glad that you didn't sell those WE's :)
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:)
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Please put the new toy in the big system before breaking it down. I would like to know how it sounds full range and all :)
I hope to someday hear a pair of those WE's.
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Tryng to take advantage of PJ's how-to-break-speakers-iron-law by taking advantage of SETs low damping and after running some models I had these 4 cu fts (twice the WE recommended volume). For these we went with solid alder on the front to allow for back mounting. The rest is plywood with very nicely matched alder veneer. Removable back panel.
In the pic Master Speaker Gerardo (who has been building keto's and my own crazy ideas for close to a decade).
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Sweet!! We all want to hear you impressions when done and broken in :^)
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There's a pair of 755As that aren't broken in yet?!?
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There's a pair of 755As that aren't broken in yet?!?
Haha - my bad, can't imagine why i said that. Must be the gin talking. :^)
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They are sounding amazing. -3dB at 60hz (per keto: the low C on the cello).
The flatest response and best sound so far is in the corners. Of course the soundstage is pretty extended but you can always imagine being at the first row at the club.
Gonna find hard justifying going back to the horns. Or maybe not when the excitement all goes away?
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Corners ???
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The room looks completely different now :)
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After a long listening night I ended up disliking the new boxes.
This morning measured them outside vs the old WE design. The yellow is the big box. The other two the WE design (did both speakers to compare, man this IS a matched pair). Of couse the WE design works much better.
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So back to the room in the WE boxes. An in room measurement:
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Both channels combined from 40 hz to 2k.
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Awesome exercise. I learned a lot. Clearly there's resonances in the big boxes that need to be tamed. I out the speakers back in them (again) and will continue moddin them to tame them without killin them.
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I was reading an artice on the 755 today where people prefered the resonant 618C cab over the stock WE cab which was very solid. They felt the resonance of the cab added to the 755 sonic signature.
http://junkyardjukebox.blogspot.com/2012/10/wealtec-755a-thinking-inside-box.html?m=1
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Yep, those are the ones I have. My big boxes were made resonant on purpose and they're even more resonant. Like a big cello. But a tad too much. The good thing is resonance can be tamed little by little 'til one find the sweet spot. Right now they're colored.
Having said that, they suck you into the music. The music has soooooul.
All this reminds me of Mr Sakuma who has a lowther pm6 in a beer barrell. And legend says Sakuma brought tears to the unbreakable and alway very tough Doc B when he heard his "concert" at VSAC (no with the beer barrell though).
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Now I know why Joe Esmilla loves them so much. Of all the things they do and they don't they just shine with a violin. The Oistrakh TP album and the WE are a match made in heaven. The orchestra behind is a mess but Oistrakh....
Time to play my old 2 track tapes where the orchestra is a mess anyway!
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Violin concerti
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Loose the orchestra, and get some more string quartets :-)
Late 60's Guarneri Quartet playing Beethoven? Or, Szeryng playing Bach?
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Yes Tom,
Chamber music is "la neta".
Not as spectacular as big scale symphonic and not an audiophile genre per nature but, in my opinion, more sofisticated and profound.
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But we disgress. Allow me to go back to my big PJ style boxes. I reviewed the outside taken measurements at higher resolution and two things became obvious.
I'll focus first on the "valley" at around 3khz. When analyzed at higher resolution it is clear that there's a profound null at 2.7khz, with a 180 degree phase change and a lot of energy delayed 72msec.
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Phase
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Delayed energy
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72mSec is 25 cm.
The inside side to side is 28cm. So it looks like there's a large resonance at that frequency that creates cancellations.
Additional resonances at 3.0, 3.1, 3.4 and 3.8 khz.
Lots of resonances to tame.
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Now, if I analyze the other valley at around 200 hz. A detailed view shows that the situation here is different. Here we don't have a null but a slow decrease in response. Also no phase change.
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So my theory here: the boxes are poorly sealed and the response is more like an ob response. And a mess below.
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Are you taking these measurements outside and away from walls? If not, it's very difficult to get accurate measurements down around 200Hz and lower.
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Outside and away from walls indeed.
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Xavier,
I just got 2 sets of Altec 755c's and I'll send the person who gave them to me a set of these installed in cabinets in order to earn the second set for myself...
Was also thinking of presenting the same offer to the person who is willing to purchase 2 sets of Feastrex D9 Monster Alnico drivers and give me one set of them in return for some absolutely awesome cabinets for the owners' pair. Word on the street is that this particular model is very affordable right now as the permanent magnet versions are being discontinued in favor of an all electromagnet product lineup. I, however, am privy to the fact that these MA's are really really good sounding. And I also already own an electromagnet 5," so why not round out the stable a little?
I bring it up to you though as if you like the 755, then a 9 inch Feastrex will just flat blow your socks off. (but hopefully not your budget). They too get right to the heart of the music, but they just have immensely greater resolution, dynamics, and are also non fatiguing. The 755 actually served as inspiration for the Feastrex designers, so much to the point that their "Type I, II, or III" electromagnet circuits are almost the same shape as the 755 electromagnet.
I worked with the Line Magnetics 755 electromagnet last year and it was alot of fun, actually. My initial impressions were somewhat luke warm in terms of their price to performance ratio, (and lack of high frequency extension/refinement, and minor hiccups at 3k)...(however...don't get me wrong I VERY much enjoyed the musical things that those drivers did well!!!) And you are so right - that they make themselves easy to listen through their faults. Good points that outweigh the bad. And it seems that the speakers I built have improved greatly anyways after a full breakin process. Enough so that I've reconsidered the situation that I probably owe it to the driver model to give them another chance.
So we'll be making an aperiodic for the 755c's we've gotten in. Should be a fun project. I like classic audio sound very much. It is so important as a designer for me to keep one ear turned back to history in order to effectively shape the things to come in single driver technology. So I've embarked on these classic speaker cabinets in the manner that I am definitely looking towards the future - to do justice to the Feastrex 5"s and 9"s.
Cheers!
-Clark
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Hi Clark,
I've never heard the Line Magnetics one but I have had several pairs of Es and Cs in the past. To be very candid with you there's no comparisons between the E/C and the As. My As are WE and have not really heard the Altec As. The E and Cs are nice but they are not magical as the As. Neither they go as "high". They need a tweeter. Two different ball games imho.
I've never heard the Featrex either. So i can't comment. Hopefully the good pricing moment lasts for a few months and I may be able to think about it.
Saludos
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Xavier, I think the 200Hz dropout is a ground reflection - unless you tested these 20 meters into the air at a test distance of 2 meters!. An experimental test is to turn the speakers upside down and see if it goes away (or moves to a higher frequency).
The combination of speaker rolloff, ground reflections, and baffle step effect makes it difficult to easily interpret what you see below 500Hz. All of these effects are calculable, and can even be done in a spreadsheet, but it's a pain in the backside to actually do it. I have not done so myself, because you still have the effects in a real room, with the addition of all the wall and ceiling reflections - a.k.a. "room acoustics"!
72mS is 25 meters, not centimeters. Is there a house 12.5 meters away that might produce a reflection?
Other possible causes are edge diffraction (look for the shareware "edge" program to explore this more easily), or the back-mounted speaker. That short wide tube in front of the speaker is amazingly effective at coloring the sound.
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PJ and I have set cabinets up on a step ladder to shift the ground reflection around a bit. IIRC we got some amazingly smooth bass response curves with that method. Shoot it once at regular height, then raise the cabinet on something that is "acoustically skinny" like a ladder and shoot it again. Check to see if the suckout shifts position.
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Thanks PJ and Dan!
Thinks are starting to make sense. The 200hz dropout absolutely has to be a floor reflection. If I input to this calculator:
http://mehlau.net/audio/floorbounce/
the parameters of my speaker and measurement distances I get a first cancelation at 277hz!
On the high end one there's my kids slide and playhouse just behind where the mike was and very likely around 12.5 m behind.
And yes, these big boxes are more colored than the good old WE slant boxes partly maybe from the wave in front of the driver and partly from being more resonant. And I'm really not gaining bass.
Still a lot to learn!.
Saludos!
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Last night I put the speakers back in the WE slanted boxes.
No measurements now. Just listening. First, they are much less colored. As Paul suggested the wave in front of the rear mounted driver does color the sound. I don't think I was getting much benefit from the big boxes since there's no hump on the response on the "small" ones and there was not perceivabable nor measured increase bass with the big ones. In could front mount the speakers on the big ones but I think the experiment is over.
I have a cool new experiment to try. I just remembered John Swensons old posts about a high impedance amp, he suggested 2 times vas. I have a pair of Lowther dx3 that has a vas of 45 liters. I can jusr drop them in this 100 liters boxes and connect them to the big pre that has 50, 200 and 500 ohm taps at around 1.5 watts. More fun!
Another finding. I believe that with the WE the Paramount 300b sound thin compared to the 2a3 ones. I'll put the 2a3 in today to confirm the observation.
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Only two moths lasted my life without horns. Yesterday I put them back. They are sounding amazing after initial adjustments. The good thing is that the WE can jump in anytime without taking the horns back.
Taking the horns out allowed me to rearrange the room and to do a few other adjustments that altogether were worth the effort of taking everything off and back again. I did learn a lot and it's reflecting in the sound.