I have found 2 sets of Specta speakers for sale in the Anaheim area I would like to purchase but the women who owns them (husband has passed) doesn't know how to take off the interface and base for shipping. Anyone in the area who could possibly help? Compensation available. Please pm me if interested. Thanks!
Thanks for the helpful comments. Fortunately, I found a pair of Spectra 6600's for sale and bought them this morning! I will be flying out to get them- will take them apart and ship back.
Really excited!
Curious as to why the serial number is blank on these??? How do I tell which is left and which is right?
Thanks!
Really excited!
Curious as to why the serial number is blank on these??? How do I tell which is left and which is right?
Thanks!
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On the top plates green or red holes with dots on mine I have also put the side designation by masking tape on each of the interfaces. Can also note a designation on the wood on the very bottom of each panel P.S. I will be having to downsize over the next year or two at which time they will be available for sale along with a model 1+1 pair and a single model 1. The interfaces for the 6600 have been updated with all new old stock circuit boards and transformers 2 years ago
I'm excited about your acquisition of a pair of Spectra 6600! I would estimate only about 25 pairs were made.
I don't know why the serial numbers are blanked out - I'm quite sure it didn't leave the factory that way. My only thought...and it's not a good one, is that the speakers were stolen and the thief blanked out the SNs to avoid identification. Let's hope that's not the case! (And this makes one ponder how one would steal a pair of speakers that big...not impossible, but challenging!) I also note that the box below the serial number has also been blocked out - this field on the label indicates whether the transformers are wired for 4 panels or 6 panels. Also, what are the white squares on the top surface of the interface? And finally, the power-on indicator appears to be a green or blue LED with a bezel around it - Acoustat always used a red LED here, without the bezel. Perhaps this was part of the "recent service".
There are physical ways to tell left from right, but over time, the colored dots may have fallen off, or the top plates may have gotten reversed. The best way to tell is by listening. The high frequencies will seem to be coming from near the inner edge of each speaker. That is, from the right edge of the left speaker, and from the left edge of the right speaker. This is easy to hear with music, and with your ear close to the speaker. Only the panels are left/right oriented. The bases and interfaces are identical.
I think I have a Spectra 2200/3300 manual in my archives - it has the procedure for assembly/disassembly, which is basically the same for the larger speakers. I will send it if I have it. Disassembly prior to shipping, or even moving the speaker (other than sliding it a short distance on the floor) is ESSENTIAL. The frame cannot withstand the twisting that would result from moving the speaker with base and interface attached. And when sliding the speaker on the floor, grip it by the base and/or interface. Do not handle it by the frame. I speak from experience on this last subject. I bought a pair of used Spectra 4400s that had, prior to my acquisition, been picked up with the interfaces and bases attached. I had to do a fair amount of repair to the frame as a result. The bases were also water-damaged, but that's another story. The speakers now look and sound great, and I will never part with them! I joke (?) with my wife that I want them playing at my funeral. Good Luck!
I don't know why the serial numbers are blanked out - I'm quite sure it didn't leave the factory that way. My only thought...and it's not a good one, is that the speakers were stolen and the thief blanked out the SNs to avoid identification. Let's hope that's not the case! (And this makes one ponder how one would steal a pair of speakers that big...not impossible, but challenging!) I also note that the box below the serial number has also been blocked out - this field on the label indicates whether the transformers are wired for 4 panels or 6 panels. Also, what are the white squares on the top surface of the interface? And finally, the power-on indicator appears to be a green or blue LED with a bezel around it - Acoustat always used a red LED here, without the bezel. Perhaps this was part of the "recent service".
There are physical ways to tell left from right, but over time, the colored dots may have fallen off, or the top plates may have gotten reversed. The best way to tell is by listening. The high frequencies will seem to be coming from near the inner edge of each speaker. That is, from the right edge of the left speaker, and from the left edge of the right speaker. This is easy to hear with music, and with your ear close to the speaker. Only the panels are left/right oriented. The bases and interfaces are identical.
I think I have a Spectra 2200/3300 manual in my archives - it has the procedure for assembly/disassembly, which is basically the same for the larger speakers. I will send it if I have it. Disassembly prior to shipping, or even moving the speaker (other than sliding it a short distance on the floor) is ESSENTIAL. The frame cannot withstand the twisting that would result from moving the speaker with base and interface attached. And when sliding the speaker on the floor, grip it by the base and/or interface. Do not handle it by the frame. I speak from experience on this last subject. I bought a pair of used Spectra 4400s that had, prior to my acquisition, been picked up with the interfaces and bases attached. I had to do a fair amount of repair to the frame as a result. The bases were also water-damaged, but that's another story. The speakers now look and sound great, and I will never part with them! I joke (?) with my wife that I want them playing at my funeral. Good Luck!
From my manual for the 6600 "Spectra arrays are MIRROR IMAGE. Each is identified by a small hole located in the TOP METAL CAPTURE PLATE, as well as a coloured dot on the bottom surface of the bottom surface of the array. Red for right and Green for left. The hole is on the LEFT side of the Left Array and the Right side of the array when viewed from the listening side"
Attached is the Spectra 22/33 owner's manual, which will help with assembly/disassembly. Also attached is a preliminary copy of the Spectra 4400/6600 owner's manual (text only, no diagrams). Also attached are some of the missing diagrams for that manual, schematic, board layout, etc. Have fun!
@AcoustatAnswerMan Thanks again for all the documentation- it will be very useful!
I have a general questions about amplifiers that may be of interest to others...
I have a pair of model 3 Acoustats I picked up a few weeks ago. They have the mk-121-c interfaces with the medallion transformers. My question regards amplifier power...
I have a class d Hypex nc1200 amp rated at 1200/700/400 watts into 2/4/8 ohms. This is peak, not rms power. When I used this amp with the model 3's, I was getting an average speaker level output of around 70dB with 85db peaks at about -20dB on my volume control. This is about as loud as I would normally listen, typically I would listen at around -25dB. I have been told that the transformers in the interfaces are rated at 200Wrms. The rms or continuous power output of the amp is probably about a third to a quarter of the peak power output values listed earlier. Further, the actual impedance of the model 3 only dips down to 1 ohm or so at high frequencies where there is little musical energy. Am I correct to assume that I will not be saturating the transformers at these listening levels? How would I know when the transformers are saturated?
Thanks for any input.
I have a general questions about amplifiers that may be of interest to others...
I have a pair of model 3 Acoustats I picked up a few weeks ago. They have the mk-121-c interfaces with the medallion transformers. My question regards amplifier power...
I have a class d Hypex nc1200 amp rated at 1200/700/400 watts into 2/4/8 ohms. This is peak, not rms power. When I used this amp with the model 3's, I was getting an average speaker level output of around 70dB with 85db peaks at about -20dB on my volume control. This is about as loud as I would normally listen, typically I would listen at around -25dB. I have been told that the transformers in the interfaces are rated at 200Wrms. The rms or continuous power output of the amp is probably about a third to a quarter of the peak power output values listed earlier. Further, the actual impedance of the model 3 only dips down to 1 ohm or so at high frequencies where there is little musical energy. Am I correct to assume that I will not be saturating the transformers at these listening levels? How would I know when the transformers are saturated?
Thanks for any input.
I have a chance to buy a pair of 1+1 with medaillon IF that are in good optical condition (bases are black piano finish, looking ok for the age, socks are more dark gray than black but have no stains and holes). I had less than half an hour's worth of listening yesterday as I was driving back from vacation. Would have to go again with an empty car anyway.
Here's my question: are these line sources all the way into the highs? from what I've read so far, they seem to have two identical panels on top of each other with no filtering applied - correct?
When I was standing about 2 m from the panels, there were almost no highs. Sitting down about 3 m away, they were there, and maybe a tad too much. I went back close to one of the speakers, and it was very evident that the highs stopped mid-speaker or about at the end of the bottom panel. I didn't test in the lower half of the bottom panel, and in my recollection, the top panel was producing mids and lows fine. From what I've read, this is near impossible. If the top panels were past their prime, they should have reduced volume throughout, right?
Bonus questions:
Here's my question: are these line sources all the way into the highs? from what I've read so far, they seem to have two identical panels on top of each other with no filtering applied - correct?
When I was standing about 2 m from the panels, there were almost no highs. Sitting down about 3 m away, they were there, and maybe a tad too much. I went back close to one of the speakers, and it was very evident that the highs stopped mid-speaker or about at the end of the bottom panel. I didn't test in the lower half of the bottom panel, and in my recollection, the top panel was producing mids and lows fine. From what I've read, this is near impossible. If the top panels were past their prime, they should have reduced volume throughout, right?
Bonus questions:
- Acoustats have been known for their pronounced Venetian blinds effect. If they are full range line sources, what causes this (other than a faulty panel)? Is it that white plastic grit that does it? My auditory impression was not a comb filter effect but really a treble source that was limited in height.
- What are those gray felt crosses that I saw in a picture posted by Answerman? They would seem to limit highs to the left, right, top and bottom of each panel?
- How does one remove the bases and boxes on a 1+1? That was one of the reasons that kept me from buying those speakers right away.
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The 1+1 has two 48" panels stacked one on top of the other. There should not be much output along the edges of these panels as there is very low diaphragm movement, unlike a cone driver, where the entire cone is moving... The majority of the panel output is in the inner center area where the diaphragm is able and free to move...
My guess is you were in a null node in that room, and may not be replicated in your listening room..
My guess is you were in a null node in that room, and may not be replicated in your listening room..
Thanks, cab and John.
Cab, in the mean time, I have read up on the dual transformer setup. The LF and HF part are joined inside the interface box. My assumption is the panels are simply paralleled. So how would highs get to the bottom panels but not to the top panels? There was this thread where someone had one top and one bottom panel that were playing the highs. It was never fully resolved but may have been down to degraded sensitivity in the panels that appeared not to be playing highs:
https://www.diyaudio.com/community/threads/acoustat-1-1-high-frequency-output-from-panels.381340/
John, I don't think I was standing in a null node, and there should not be any null node at several kHz. I had this distinct impression of no highs from the top panels right about a foot from the speaker, moving my head along the panel, standing 2 m from the speakers and sitting and getting up at 3 m. I am not sure if the mids and lows were also attenuated. I could kick myself for not checking.
I am confused about radiating areas in those panels. First of all, do we agree the panels in the 1+1 are paralleled electrically? If the stators are evenly spaced, all of the area of each panel should be radiating. Of course, the parts near the edges run out of excursion, but this should be mainly a low frequency thing.
This gets me to those felt crosses (see picture lifted from MrAcoustat's flickr and link to post by AcoustatAnswerMan)
https://www.diyaudio.com/community/attachments/randall-02-jpg.388637/
I am not sure if those crosses live on the rear side, front side or both. If the felt is very dense and they live on the back only, I could imagine they serve as a reflector in the center region, maybe more so for highs if they have a foil or coating of glue where they are connected to the grit.
If so, this would result in a bit of comb filtering symmetrical to the border between the top and bottom panel, but again not what I heard.
Cab, in the mean time, I have read up on the dual transformer setup. The LF and HF part are joined inside the interface box. My assumption is the panels are simply paralleled. So how would highs get to the bottom panels but not to the top panels? There was this thread where someone had one top and one bottom panel that were playing the highs. It was never fully resolved but may have been down to degraded sensitivity in the panels that appeared not to be playing highs:
https://www.diyaudio.com/community/threads/acoustat-1-1-high-frequency-output-from-panels.381340/
John, I don't think I was standing in a null node, and there should not be any null node at several kHz. I had this distinct impression of no highs from the top panels right about a foot from the speaker, moving my head along the panel, standing 2 m from the speakers and sitting and getting up at 3 m. I am not sure if the mids and lows were also attenuated. I could kick myself for not checking.
I am confused about radiating areas in those panels. First of all, do we agree the panels in the 1+1 are paralleled electrically? If the stators are evenly spaced, all of the area of each panel should be radiating. Of course, the parts near the edges run out of excursion, but this should be mainly a low frequency thing.
This gets me to those felt crosses (see picture lifted from MrAcoustat's flickr and link to post by AcoustatAnswerMan)
https://www.diyaudio.com/community/attachments/randall-02-jpg.388637/
I am not sure if those crosses live on the rear side, front side or both. If the felt is very dense and they live on the back only, I could imagine they serve as a reflector in the center region, maybe more so for highs if they have a foil or coating of glue where they are connected to the grit.
If so, this would result in a bit of comb filtering symmetrical to the border between the top and bottom panel, but again not what I heard.
Attachments
The Model 1+1 is easy to disassemble, which is highly recommended before transporting the speaker. Note the black box at the rear, called the "interface". After the speaker has been thoroughly discharged for several hours, remove the (4) allen head screws (2 on each side) of the interface chassis. Then lift off the chassis and disconnect the (3) groups of wires connecting the interface to the panels. This leaves the sides plates as the connection from base to panels. Remove the 4 large bolts inside to detach the panel from the side plates. Be careful - this is a two-person job. Then from the bottom side of the base, remove another 4 large bolts that secure the side plates. For transporting, it's a good idea to temporarily reinstall the sides plates to the interface chassis, to protect its innards.
The 1+1 consists of two vertically stacked, identical panels. Both panels are driven the same at full range. Due to the radiation pattern and large area of the speaker, one really can't judge its output at close range. This must be done from somewhere close to, or at the normal listening position. Being a narrow line array, the "sweet spot" is fairly narrow (but oh so SWEET!), with a noticeable drop-off in highs outside that area. It's the nature of the beast.
The felt blocks are present on the rear of the panels only, so they do not affect the highs radiated from the front of the speaker. Their purpose is to damp unwanted resonances and are a feature of every model produced by Acoustat. Nearly all ESL panels use some form of resonance damping, this is just Acoustat's way of doing it. If the felt pads are coming loose (it does happen), they can be re-applied to the panels using a spray contact adhesive, applied to the felt (only). Once the adhesive becomes tacky, just press the felt back into place.
I've heard talk of the so-called "venetian blind" effect, but frankly, I've never experienced it. The taller models (like the 1+1) exhibit remarkable uniformity in vertical dispersion, and they sound pretty much the same either sitting or standing. The shorter models, of course, have more limited vertical dispersion, and with these models, the height of the listening position becomes more important.
The 1+1 consists of two vertically stacked, identical panels. Both panels are driven the same at full range. Due to the radiation pattern and large area of the speaker, one really can't judge its output at close range. This must be done from somewhere close to, or at the normal listening position. Being a narrow line array, the "sweet spot" is fairly narrow (but oh so SWEET!), with a noticeable drop-off in highs outside that area. It's the nature of the beast.
The felt blocks are present on the rear of the panels only, so they do not affect the highs radiated from the front of the speaker. Their purpose is to damp unwanted resonances and are a feature of every model produced by Acoustat. Nearly all ESL panels use some form of resonance damping, this is just Acoustat's way of doing it. If the felt pads are coming loose (it does happen), they can be re-applied to the panels using a spray contact adhesive, applied to the felt (only). Once the adhesive becomes tacky, just press the felt back into place.
I've heard talk of the so-called "venetian blind" effect, but frankly, I've never experienced it. The taller models (like the 1+1) exhibit remarkable uniformity in vertical dispersion, and they sound pretty much the same either sitting or standing. The shorter models, of course, have more limited vertical dispersion, and with these models, the height of the listening position becomes more important.
As stated above, both panels are driven equally and full-range. If a panel works at all, then it should be producing all frequencies equally. If one panel has no output, one of the wires connecting it to the interface may have come loose. The panels pretty much work, or they don't, and there isn't really any mechanism (or fault) whereby a panel would produce lows and not highs. (this comment applies only to pre-Spectra models). In the Spectra models, not all panel area is driven full-range.