GM said:
Yep, Honolulu's like that. Traffic even worse than Atlanta - but not as fast.
Couldn't believe how dark it was when we moved over to Maui. We live "in town" and can sit in the yard and clearly see the Milky Way. Go down to the beach and it's super dark. Skies are amazing. I ride my bike home from work at Midnight everyday, the night sky is always a treat.
For the comb filtering, are you talking about the multicell horns? I've always wonder about that, how do those darn multicell things work? In my experience with them, I sure didn't notice any comb filtering. In fact, they were the best sounding horns I've ever heard. The 1505s, that is. My experience with the big 1803 is limited. It certainly has its fan, tho.
The Mod!
Oops...I guess I might be the hi-jacker that Geof refered to when he started this thread! Maybe it would be best to explain the circumstances, so I don't look like a rebel with no respect....
I would never, never destroy a fully functioning classic in order to make something new. This was more of an "organ donor" situation.
I came across this pair of Altec Lansing 508 towers at an estate sale about 7 or 8 years ago.
Now the 508s are not the horn loaded beauties from years before. But they are still beauties in thier own right. They utilized two carbon fiber 8" woofers and shiny, crome-silver domes for midrange and tweeter.(I mistakenly told someone here, just yesterday, that they were 6 1/2" woofers ...Sorry, it's been about 4 years since I have worked with them and I simply forgot the correct size.)
The moment I pulled the grill off one of the units, I flashed back to myself as an 11 year old boy, flipping through the pages of my dad's latest issue of Stereo Review, and being enchanted with the Altec ad for the very speaker now before me. I remember the ad's text had me totally convinced that a carbon fiber woofer was absolutely the height of audio perfection! "One day", I imagined, "these speakes will be mine, along with the Marantz receiver on back page". Well, I eventually got the Marantz receiver (albeit a much newer version), but by the time I could afford such things, the Altec 508s were long gone, and other speakers had struck my fancy.
So here was my chance to have the 508s, even though I really knew nothing about them at all. Still, I couldn't resist.
The first unit that I pulled the grill off of looked to be in pretty good shape; a little foam rot, but that was easy to repair. My heart sank when I pulled the grill off the second unit. It was like the abused twin. All of the surrounds were totally rotted away, and the domes were in bad shape. It was like they had been attacked by some maniac bent on totally destroying all shiny orbs. They were smashed and cracked beyond repair. Of course, I bought them anyway.
First I ordered the foam repair kits, then set about finding the replacement domes...No luck. I repaired the woofers, figuring I'd eventually find the domes for the abused twin. Still not finding the domes after quite some time, I let the project go. The 508s sat neatly in my garage, for years.
When I first repaired the woofers, I was actually suprised by the sound quality of the undamaged 508. I hadn't expected it to be as good as it was. It had nice, full midrange and a great midbass/bass that was detailed, warm, tight, and..."fast"! ...Really fast!! I suspose it was right then that I got the idea that these woofers might make an excellent match with an Air Motion Transformer.
(You see, AMTs are hard to pair with cone woofers. AMT's respond to the source signal so quickly that you can actually hear the "sluggishness" of the cone woofer in compairison. There are all kinds of unique designs using AMTs that try to compensate for this difference, usually by placing the woofer at an extreme ange with the AMT litterally suspended inches above the rearmost edge of the woofer cone. I believe more technically sophisticated people refer to this difference as a phase difference. It more or less boils down to a difference in speed...one driver is producing a given sound part more quickly than, or before, the other.)
Fast forward to about 4 years ago. I was in the mood to build something with a couple of AMTs that I had laying around, just for the fun of it. I decided, to use the woofers from the 508s as sort of an experiment. After all, I had actually heard the sound character of these woofers. In my other projects, I had orderd the woofers sight unseen (unheard). I wasn't being very serious about this project, since I had no technical information on the woofers except for the impeadance and some unsophisticated measurements that I had taken.
I copied the cabnet dimensions of the 508 exactly, placing the two woofers stacked, at the top of the front baffle, and mounting the AMTs on the cabnet top. I also took a chance and designed a variation of a crossover that I had seen only once, in a very early ESS Heil AMT system that had sounded quite unbelievable. So I had a 6db/octive low pass, and a L-R 12db/oct high pass: A trickey thing to pull off correctly...I probably messed it up! I also used flat ribbon inductors and really fancy (expensive) caps, again just for fun.
Once "the experiment" was done and I had played with it awhile, I'd just put the 508 woofers back, and recycle the other parts in a new project.
Thing is....somehow I had blundered my way into the best sounding speakers I have ever made, and among the best I have ever heard (which is saying something because I used to sell high-end audio). The blend between the Altec woofers and the AMT was practically seamless! They have been part of my best sound system ever since.
I finally did find replacement domes for the abused 508 twin. Now they sit, patiently waiting for thier woofers to return, which I'm sure one day they will. The new Tymphany LAT "air motion transformer" woofer will assure a future project that will hopefully outmode "the experiment"s (as soon as they make one available with the right specs).
Meantime, to honor the Altecs, I have used the 508 grills with the Altec nameplate, for the front grill of "the experiment"s (with a matching "box" grill sitting on top to house the AMTs). When people ask about them, which they usually do upon hearing them, I say "the bottom part is Altec Lansing, the top part is ESS, and the crossover is...well... it's me!
Oops...I guess I might be the hi-jacker that Geof refered to when he started this thread! Maybe it would be best to explain the circumstances, so I don't look like a rebel with no respect....
I would never, never destroy a fully functioning classic in order to make something new. This was more of an "organ donor" situation.
I came across this pair of Altec Lansing 508 towers at an estate sale about 7 or 8 years ago.
Now the 508s are not the horn loaded beauties from years before. But they are still beauties in thier own right. They utilized two carbon fiber 8" woofers and shiny, crome-silver domes for midrange and tweeter.(I mistakenly told someone here, just yesterday, that they were 6 1/2" woofers ...Sorry, it's been about 4 years since I have worked with them and I simply forgot the correct size.)
The moment I pulled the grill off one of the units, I flashed back to myself as an 11 year old boy, flipping through the pages of my dad's latest issue of Stereo Review, and being enchanted with the Altec ad for the very speaker now before me. I remember the ad's text had me totally convinced that a carbon fiber woofer was absolutely the height of audio perfection! "One day", I imagined, "these speakes will be mine, along with the Marantz receiver on back page". Well, I eventually got the Marantz receiver (albeit a much newer version), but by the time I could afford such things, the Altec 508s were long gone, and other speakers had struck my fancy.
So here was my chance to have the 508s, even though I really knew nothing about them at all. Still, I couldn't resist.
The first unit that I pulled the grill off of looked to be in pretty good shape; a little foam rot, but that was easy to repair. My heart sank when I pulled the grill off the second unit. It was like the abused twin. All of the surrounds were totally rotted away, and the domes were in bad shape. It was like they had been attacked by some maniac bent on totally destroying all shiny orbs. They were smashed and cracked beyond repair. Of course, I bought them anyway.
First I ordered the foam repair kits, then set about finding the replacement domes...No luck. I repaired the woofers, figuring I'd eventually find the domes for the abused twin. Still not finding the domes after quite some time, I let the project go. The 508s sat neatly in my garage, for years.
When I first repaired the woofers, I was actually suprised by the sound quality of the undamaged 508. I hadn't expected it to be as good as it was. It had nice, full midrange and a great midbass/bass that was detailed, warm, tight, and..."fast"! ...Really fast!! I suspose it was right then that I got the idea that these woofers might make an excellent match with an Air Motion Transformer.
(You see, AMTs are hard to pair with cone woofers. AMT's respond to the source signal so quickly that you can actually hear the "sluggishness" of the cone woofer in compairison. There are all kinds of unique designs using AMTs that try to compensate for this difference, usually by placing the woofer at an extreme ange with the AMT litterally suspended inches above the rearmost edge of the woofer cone. I believe more technically sophisticated people refer to this difference as a phase difference. It more or less boils down to a difference in speed...one driver is producing a given sound part more quickly than, or before, the other.)
Fast forward to about 4 years ago. I was in the mood to build something with a couple of AMTs that I had laying around, just for the fun of it. I decided, to use the woofers from the 508s as sort of an experiment. After all, I had actually heard the sound character of these woofers. In my other projects, I had orderd the woofers sight unseen (unheard). I wasn't being very serious about this project, since I had no technical information on the woofers except for the impeadance and some unsophisticated measurements that I had taken.
I copied the cabnet dimensions of the 508 exactly, placing the two woofers stacked, at the top of the front baffle, and mounting the AMTs on the cabnet top. I also took a chance and designed a variation of a crossover that I had seen only once, in a very early ESS Heil AMT system that had sounded quite unbelievable. So I had a 6db/octive low pass, and a L-R 12db/oct high pass: A trickey thing to pull off correctly...I probably messed it up! I also used flat ribbon inductors and really fancy (expensive) caps, again just for fun.
Once "the experiment" was done and I had played with it awhile, I'd just put the 508 woofers back, and recycle the other parts in a new project.
Thing is....somehow I had blundered my way into the best sounding speakers I have ever made, and among the best I have ever heard (which is saying something because I used to sell high-end audio). The blend between the Altec woofers and the AMT was practically seamless! They have been part of my best sound system ever since.
I finally did find replacement domes for the abused 508 twin. Now they sit, patiently waiting for thier woofers to return, which I'm sure one day they will. The new Tymphany LAT "air motion transformer" woofer will assure a future project that will hopefully outmode "the experiment"s (as soon as they make one available with the right specs).
Meantime, to honor the Altecs, I have used the 508 grills with the Altec nameplate, for the front grill of "the experiment"s (with a matching "box" grill sitting on top to house the AMTs). When people ask about them, which they usually do upon hearing them, I say "the bottom part is Altec Lansing, the top part is ESS, and the crossover is...well... it's me!
matt28sr, be assured, you were not the culprit. 'Twas me!
Interesting story about your 508s. I think all floor standing Altecs have a sound of their own. And those that know it, remember it. Like you, my current main system is not Altec, but Altec inspired.
No, they're not mine. They are in this interesting article.
http://www.gtaust.com/filter/04/09.shtml
http://www.gtaust.com/filter/06/08.shtml
http://www.gtaust.com/filter/05/07.shtml
Interesting story about your 508s. I think all floor standing Altecs have a sound of their own. And those that know it, remember it. Like you, my current main system is not Altec, but Altec inspired.
No, they're not mine. They are in this interesting article.
http://www.gtaust.com/filter/04/09.shtml
http://www.gtaust.com/filter/06/08.shtml
http://www.gtaust.com/filter/05/07.shtml
Attachments
Hi all, my experience with Altec started about mid 1975. My system then was a pair of 3 way Peerless based on the 12" woofer, 5" sealed back cone mid, and the 1" soft dome tweeter. This system was reported to be fairly good. After I assembled the cabinets, I couldn't work out why. Nice top end. The mids were restrained. The bass was empty.
It didn't make any difference connected to my Revox G36 Tape deck, my Layfayette tube amp (PP 6BQ5s), or my Playmaster 10+10.
Somewhere, I had heard "Funeral for a friend" (Elton Johns band) being used to set up the sound in a venue. The ARP synth sounded fantastic. Why couldn't I have that at home. I didn't know what they were at the time, but I remembered the horns on top of the bass boxes.
So the search began. I had a friend that was starting in out in speaker manufacturing. So as well as listening to a lot of "big stuff", I got to listen to his creations, based on Philips drivers. They were better than the Peerless in many ways, but not what I was after.
I bought a pair of Wharfedales from my father, had some cabinets made, and gave them to my mother in law. Hooked them up to her crumby Sanyo console, played a Daily Wilson Big Band LP, then went outside to kick my self. But it wasn't that bad, I was in the process of building a 50W/chan amp.
My mate became an agent for Altec, and suggested I drop in and have a listen. I must have gotten rather picky. The Model 9's weren't good enough. The Santanas were nice, but the Barcelona's did it.
The big problem with the Barcelona's was that they wanted a big room to sound right. I concluded that Americans had lounge rooms much bigger than ours. The bass was fine, just the top end.
So it was organised that I could have a pair of the 411-8As. I figured starting with those I could work on the top end.
I didn't know it then, but I was to embark on a frustrating excersize. How to get that clarity and presence in a typical Australian lounge room.
The first attempt consisted of 4 4" drivers in a verticle array. Plenty of spread, with about 10 deg verticle beem, with plenty of ping pong effect about the crossover. That lasted a week.
2nd try, I mounted the same drivers in an enclosure with 4 baffles, angled so the polar plots would provide a good spread over the room. Much better. But still didn't do sax. Let's try bia-amping. A crossver was quickly built, and an Eroica power amp purchased for the high side.
While I was testing this combo, a neighbour out walking his dog knocked on the door. Ready to grovel about the noise, I opened the front door, and to my surprise, he was just courious. I explained the situation, and he offered to bring some drivers around that he imported from England. They turned out to be Jordan Watts units.
Very clean and crisp. Almost clinical. Showed up a problem in the Eroica amp. It may have been transient intermodulation. That term didn't wasn't known then. And still didn't pass the sax test.
I still had a pair of Richard Allen 10 in widerange units. Let's try them, standing beside the 411s. I felt as though I was getting somewhere. Had to try some Wharfedales. Even thought of swapping them over with my mother in law's. Low and behold, a pair was advertised in the paper. Secured those, and started to plan an enclosure to sit on top of the bass boxes.
Now, somehow I managed to cook the voice coils in the R-As. Getting those repaired led me to the gentleman that modified my Wharfedales, and are still in use today. The v-c's were rewound to 8 ohms, and shorter. He suggested to replace the alloy domes and whizzer cones with larger units, and treat the cloth surrounds.
They were then mounted on baffles, and a lined terra cotta pot glued over the back. A simple 6db/octave xo at 500. Too bright! Off to Tandy to get some attenuators. Pulled them back 10db, and enjoyed.
Altec inspired. Lounge room friendly. At last. Then the pots came off. OBed using fibro cement baffles. I had 15 years out of that setup.
Geoff
It didn't make any difference connected to my Revox G36 Tape deck, my Layfayette tube amp (PP 6BQ5s), or my Playmaster 10+10.
Somewhere, I had heard "Funeral for a friend" (Elton Johns band) being used to set up the sound in a venue. The ARP synth sounded fantastic. Why couldn't I have that at home. I didn't know what they were at the time, but I remembered the horns on top of the bass boxes.
So the search began. I had a friend that was starting in out in speaker manufacturing. So as well as listening to a lot of "big stuff", I got to listen to his creations, based on Philips drivers. They were better than the Peerless in many ways, but not what I was after.
I bought a pair of Wharfedales from my father, had some cabinets made, and gave them to my mother in law. Hooked them up to her crumby Sanyo console, played a Daily Wilson Big Band LP, then went outside to kick my self. But it wasn't that bad, I was in the process of building a 50W/chan amp.
My mate became an agent for Altec, and suggested I drop in and have a listen. I must have gotten rather picky. The Model 9's weren't good enough. The Santanas were nice, but the Barcelona's did it.
The big problem with the Barcelona's was that they wanted a big room to sound right. I concluded that Americans had lounge rooms much bigger than ours. The bass was fine, just the top end.
So it was organised that I could have a pair of the 411-8As. I figured starting with those I could work on the top end.
I didn't know it then, but I was to embark on a frustrating excersize. How to get that clarity and presence in a typical Australian lounge room.
The first attempt consisted of 4 4" drivers in a verticle array. Plenty of spread, with about 10 deg verticle beem, with plenty of ping pong effect about the crossover. That lasted a week.
2nd try, I mounted the same drivers in an enclosure with 4 baffles, angled so the polar plots would provide a good spread over the room. Much better. But still didn't do sax. Let's try bia-amping. A crossver was quickly built, and an Eroica power amp purchased for the high side.
While I was testing this combo, a neighbour out walking his dog knocked on the door. Ready to grovel about the noise, I opened the front door, and to my surprise, he was just courious. I explained the situation, and he offered to bring some drivers around that he imported from England. They turned out to be Jordan Watts units.
Very clean and crisp. Almost clinical. Showed up a problem in the Eroica amp. It may have been transient intermodulation. That term didn't wasn't known then. And still didn't pass the sax test.
I still had a pair of Richard Allen 10 in widerange units. Let's try them, standing beside the 411s. I felt as though I was getting somewhere. Had to try some Wharfedales. Even thought of swapping them over with my mother in law's. Low and behold, a pair was advertised in the paper. Secured those, and started to plan an enclosure to sit on top of the bass boxes.
Now, somehow I managed to cook the voice coils in the R-As. Getting those repaired led me to the gentleman that modified my Wharfedales, and are still in use today. The v-c's were rewound to 8 ohms, and shorter. He suggested to replace the alloy domes and whizzer cones with larger units, and treat the cloth surrounds.
They were then mounted on baffles, and a lined terra cotta pot glued over the back. A simple 6db/octave xo at 500. Too bright! Off to Tandy to get some attenuators. Pulled them back 10db, and enjoyed.
Altec inspired. Lounge room friendly. At last. Then the pots came off. OBed using fibro cement baffles. I had 15 years out of that setup.
Geoff
Re: that's fun ...
Very infrequent poster, but I had to add my 2cents to Charles post. I own a pair of A7s with the same drivers, 511 horn, but with aftermarket x-overs that I was not happy with at all. Sound best described as muddy or indistinct!
Knowing that I likely had all the components needed to assemble a 1st order x-over, poked around the spare part bins and pulled out a 1mh inductor and caps, all Solen, and quickly put together a x-over with a crossing point of 1.2khz then install it.
What a dramatic improvement over the original x-over. Initially the high frequency. were a bit overpowering, but after trying various resisters, settled for 12ohms in serious which gave a fair balance between the low and high frequencies.
I cannot wait to get home tonight to make some further tweaks to the x-over. I'll keep people posted on my little audio adventure.
Cheers
PS Must thank Charles for the inspiration
Hello allCharles said:... I'm just listening to my mono Voice.
I love the sound.
I have 416 bass, 808 HF driver with a radian replacement diaphragm.
Clicke here and scroll down for a pic:
http://www.mother-of-tone.com/mother.htm
I operate this Voice with a 6dB crossover, just a coil and a cap. Many of the more proficient Altec owners have complex crossies, but I happen to enjoy the simpler sound
Take a look at the spruce horn. This is the biggest improvement to the Voice that I can ever imagine.
I have a 2nd pair of original voices with aluminium horns and I keep the alu horns there, just to switch back and forth and realize how good the spruce horn sounds in comparison.
Fun ...
Charles
Very infrequent poster, but I had to add my 2cents to Charles post. I own a pair of A7s with the same drivers, 511 horn, but with aftermarket x-overs that I was not happy with at all. Sound best described as muddy or indistinct!
Knowing that I likely had all the components needed to assemble a 1st order x-over, poked around the spare part bins and pulled out a 1mh inductor and caps, all Solen, and quickly put together a x-over with a crossing point of 1.2khz then install it.
What a dramatic improvement over the original x-over. Initially the high frequency. were a bit overpowering, but after trying various resisters, settled for 12ohms in serious which gave a fair balance between the low and high frequencies.
I cannot wait to get home tonight to make some further tweaks to the x-over. I'll keep people posted on my little audio adventure.
Cheers
PS Must thank Charles for the inspiration
Hi Cal, what I was thinking with your stacked horns, was to try shelving the the lower horn at 1200, rather than rolling it off.
Seems a shame to have that horn only covering a bit over an octave.
See the rough sketch attached.
And what is this "Bench Racing"? Sounds intriging.
Grasshopper, I found with my 411s, off the shelf inductors were "sad"
The 2.5mH ones I bought muddied up the sound. Found they had 1.5 ohms as well. I hand wound a pair of 2.6mH using 16 AWG. Huge difference. Only 6db/oct. The high side was a bank of 20 x 2 uf AEE al foil - not much sereis inductance in that.
Cheers,
Geoff
Seems a shame to have that horn only covering a bit over an octave.
See the rough sketch attached.
And what is this "Bench Racing"? Sounds intriging.
Grasshopper, I found with my 411s, off the shelf inductors were "sad"
The 2.5mH ones I bought muddied up the sound. Found they had 1.5 ohms as well. I hand wound a pair of 2.6mH using 16 AWG. Huge difference. Only 6db/oct. The high side was a bank of 20 x 2 uf AEE al foil - not much sereis inductance in that.
Cheers,
Geoff
Attachments
Re: Re: Re: that's fun ...
Thanks for posting that. I suppose it's for the A7-500?
Alas a lot of the values are hard to read (common problem with 1 bit gifs).
I can personaly attest to the fact that Mr. Hiraga builds a great sounding crossover. Though I haven't heard this one, IIRC.
Zen Mod said:
Thanks for posting that. I suppose it's for the A7-500?
Alas a lot of the values are hard to read (common problem with 1 bit gifs).
I can personaly attest to the fact that Mr. Hiraga builds a great sounding crossover. Though I haven't heard this one, IIRC.
Hi Geoff,Geoff H said:
Right now I have just fooled around with fixed L-pads but I hear something a bit strong and I think it's around 1-3K so I'll experiment with some notches and see if I can tame it a bit.
Isn't a shelving network just another name for a fixed (non-variable) L-pad where you have incoporated the frequency of shelving independent of the XO? If so, that's not quite what I wish. I just wish to rework the padding so I am able to get more off each end of the midrange and cut back the middle a bit.
600 - 5K is what it covers
Thank you.
What we used to call "race car sets" Another member is heavily into it and our beloved GM has been involved in the past. He can correct me if that's wrong.
Shelving, as I understand it, ie on the Barcelonas (Altec network #30904) attenuates the lower end of the horn, without as much, if any, on the top end. Just flattens out the response. On the 411 based systems, there is a big difference in sensitivity, 8 or 9 dB from memory.
FWIW, when I have played with that sort of thing, found it easier to disconnect the top end, run the "mid" on high pass only. Once that's sorted, work on the top end.
Wouldn't life be easier with 2-20 uf variable caps?
Don't take the values on that drawing as gospell. They're calculated on 8 ohms resistive.
Bench racing sounds like what we call slot cars. Most of the thrills, no bruises or panel shop expenses. You big kids! When's the next meet?
Geoff
FWIW, when I have played with that sort of thing, found it easier to disconnect the top end, run the "mid" on high pass only. Once that's sorted, work on the top end.
Wouldn't life be easier with 2-20 uf variable caps?
Don't take the values on that drawing as gospell. They're calculated on 8 ohms resistive.
Bench racing sounds like what we call slot cars. Most of the thrills, no bruises or panel shop expenses. You big kids! When's the next meet?
Geoff
Cal Weldon said:
Greets!
Ah, OK, my comments assumed combining them over a wide BW to take advantage of the smoother, more robust response of the larger combined mouths. FWIW, using an 811 as a tweeter will in theory sound more cohesive with it positioned between the 511 and woofer, but never having heard the combo either way AFAIK............. with your nifty tie bkt. it shouldn't be hard to try though.
Interesting about the Seleniums, seems to me these were discussed awhile back on the HE forum and the consensus was that they wouldn't mate well enough with the 511/811 to make extended, high SQ HF.
GM
Cal Weldon said:GM,
A matter of respect. I'll call you G from now on.
With that aside, this has been a fun little project. I like this kind of thing.
Greets!
OK, thanks for that. FWIW, I'm so used to 'GM', both written and spoken, that anything else in a casual environment seems kind of strange.
Anyway, understood, you're apparently as easily amused as I am
and good to know it works well enough.GM