I once called Acoustat with a question about my 1+1's.
I got xfered to Jim Strickland. I had a good long talk with Jim. I was impressed that he would take a call from a neurotic audiophile asking weenie questions. I bet questions he has answered hundreds of times before.
I just finished rebuilding my Spectra 6600's with all new frames and bases. For the bases, I did something a bit different in an effort to add strength...
First, I had a plate of 1/8" steel cut an inch shorter in width and length than the finished base. I had tee nuts welded to this plate. Then I had a second, smaller plate of 1/8" steel cut with a hole pattern that matched the tee nut locations. I bolted the small plate to the bottom of the interface. I then cut a solid, 3/4" oak plank, made up of strips of oak, to the finished base size, drilled holes to match the tee nuts. I placed this oak plank on top of the large steel plate then put the smaller steel plate with the interface attached on top of the oak plank, sandwiching the oak plank between the steel plates, then bolted them together. I ended up cutting the oak plank about 1" shorter in length and width, and planing it to 5/8" before sandwiching it. I then glued on strips to the back edge and sides which where L shaped to cover the top and side edges of the bottom plate. I did the same for the front edge except I used several neo magnets countersunk into to oak strip so that I could remove it if I have to de attach the speaker itself from the interface in the future. Worked out great and the steel plate slides easily on the concrete floor.
Those who are observant will notice the 1/4" thick angle brackets I added to each side of the interface, made from cut sections of 6"x6" 1/4" steel angle.
First, I had a plate of 1/8" steel cut an inch shorter in width and length than the finished base. I had tee nuts welded to this plate. Then I had a second, smaller plate of 1/8" steel cut with a hole pattern that matched the tee nut locations. I bolted the small plate to the bottom of the interface. I then cut a solid, 3/4" oak plank, made up of strips of oak, to the finished base size, drilled holes to match the tee nuts. I placed this oak plank on top of the large steel plate then put the smaller steel plate with the interface attached on top of the oak plank, sandwiching the oak plank between the steel plates, then bolted them together. I ended up cutting the oak plank about 1" shorter in length and width, and planing it to 5/8" before sandwiching it. I then glued on strips to the back edge and sides which where L shaped to cover the top and side edges of the bottom plate. I did the same for the front edge except I used several neo magnets countersunk into to oak strip so that I could remove it if I have to de attach the speaker itself from the interface in the future. Worked out great and the steel plate slides easily on the concrete floor.
Those who are observant will notice the 1/4" thick angle brackets I added to each side of the interface, made from cut sections of 6"x6" 1/4" steel angle.
Attachments
As a former cabinet builder, carpenter, etc. I have some experience with wood. If you seal the wood before it warps with a couple coats it is much less likely to warp or crack. Oak is pretty stiff so may not warp even under the conditions described. If you have a choice go with thicker wood as even 1/4" (6mm+) more makes it a LOT stiffer.
Also let the piece of wood acclimate for a couple weeks before you do much with it. If it was locally sourced, not shipped in from a different climate, then you could plane it if needed and cut it to size, as these actions sometimes lead to an immediate warping, which you want to know sooner. Then I would lean it against an interior wall so that it gets air with your home's moisture content on both sides of it. But not near a bathroom or kitchen, and not where sunlight hits it.
I would be more cautious if you change climates such as from desert Southwest to a humid climate or vice versa. Over time it will absorb or give off some moisture which might lead to cracking or warping especially if one side is not exposed and the other is. I suppose you could put strips of wood such as 1x2 under it to prop it up for a couple months if you move.
Hope this helps.
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Loving them! I am using a set of subwoofers for some really impressive bass, crossing them over at 60Hz. I am adding room treatments and plan to dial everything in with dsp, both the crossovers as well as speaker and room correction. I also plan to add 2 more subwoofers to get some distributed bass benefits. Not there yet but working on it. Hopefully by the end of Spring! Thanks for all of your help!
Andy,
I know loose diaphragms affect Acoustats' low frequency response. It seems that would also reduce the high frequency response, as tight diaphragms can be higher pitched, but does it actually?
I know loose diaphragms affect Acoustats' low frequency response. It seems that would also reduce the high frequency response, as tight diaphragms can be higher pitched, but does it actually?
Do you (anyone) have a full, clear frequency response graph of a fully functioning Medallion model? I am especially interested in Model 3 and 2+2.
I want to see the high frequency roll off, and the low frequency roll off too.
I want to see the high frequency roll off, and the low frequency roll off too.
Hello Acoustat enthusiasts!
Way back in the day (1993?) I had a pair of Spectra 2200s. Enjoyed them for a few years, regret selling them. I've got the ESL bug again after recently hearing a friend's Quad ESL63s.
So I recently acquired a pair of Acoustat 1+1s in good working condition. One bottom panel has attenuated treble, so looking to replace/repair/refurbish as needed. Since the upper panel in that same speaker seems to be fine, I'm assuming the electronics are in good working order. Specific hardware details shown in included pics.
I'm assuming I need to scare up a fully functioning panel to get these working properly as a stereo pair. I do have the option of buying another set of Acoustats (can't remember the model) from the same seller, condition unknown, on the gamble that at least one of the panels from them is good.
I also would like to replace the grill socks, which are in good shape (no tears or holes), but just really grungy. Washing them is an option. They are the ivory color. But if I'm going to the trouble of removing them anyway, a new spandex set would be nice.
Question: Are the Acoustat panels germane to all models? That is, will a panel from a different Acoustat model work properly in the 1+1s?
Question 2: What are the typical, known issues with the electronics for this specific variant?
Any tips on the best resources for acquiring/refurbishing/repairing the electronics and the panels in particular would be greatly appreciated. I'm hands on with servicing or refreshing the electronics, but am unfamilar with working on the panels themselves.
TIA
Steve in NM
Way back in the day (1993?) I had a pair of Spectra 2200s. Enjoyed them for a few years, regret selling them. I've got the ESL bug again after recently hearing a friend's Quad ESL63s.
So I recently acquired a pair of Acoustat 1+1s in good working condition. One bottom panel has attenuated treble, so looking to replace/repair/refurbish as needed. Since the upper panel in that same speaker seems to be fine, I'm assuming the electronics are in good working order. Specific hardware details shown in included pics.
I'm assuming I need to scare up a fully functioning panel to get these working properly as a stereo pair. I do have the option of buying another set of Acoustats (can't remember the model) from the same seller, condition unknown, on the gamble that at least one of the panels from them is good.
I also would like to replace the grill socks, which are in good shape (no tears or holes), but just really grungy. Washing them is an option. They are the ivory color. But if I'm going to the trouble of removing them anyway, a new spandex set would be nice.
Question: Are the Acoustat panels germane to all models? That is, will a panel from a different Acoustat model work properly in the 1+1s?
Question 2: What are the typical, known issues with the electronics for this specific variant?
Any tips on the best resources for acquiring/refurbishing/repairing the electronics and the panels in particular would be greatly appreciated. I'm hands on with servicing or refreshing the electronics, but am unfamilar with working on the panels themselves.
TIA
Steve in NM
I just got a Hafler Xl-600 and all the labels are from Rockford.
Xl-600 was released in 1989
The Xl-280 was released in 1987
Was the Xl-600 designed by Jim or Erno ?
Xl-600 was released in 1989
The Xl-280 was released in 1987
Was the Xl-600 designed by Jim or Erno ?
The Hafler XL600 was an outgrowth of the original DH-200 which was largely designed by Erno Borbely. However, credit should go to Harry Klaus, who brought-to-market all of the Hafler amplifiers prior to the Transnova series. Several of the amplifier models, including XL280 and XL600, continued under the "Hafler Div of Rockford Corp" banner until the introduction of the Transnova models. These were designed by Jim Strickland and were outgrowth of the original Acoustat TNT200.
I am not aware of any possible fault in the panel that would cause diminished high frequencies. These panels either work or they don't, the most common faults being extraneous noises caused by loose tension in the diaphragm or dirt caught in the gap. I would look towards the electronics instead. Since only one speaker is having an issue, this is easy to verify by swapping interfaces between panels. If the problem moves with the interface, then the problem is with the interface. Please report back with your findings. You may have a bad capacitor in the HV blending circuit, or a faulty bias supply. The latter is fairly common and easy to fix. Although a low bias voltage should affect all frequencies equally, it is possible to perceive this as reduced HF output.
If you instead verify that the panel is at fault, we can discuss panel replacement further.
I cannot answer your question. Since this is a theoretical question not unique to the Acoustat product, raising this question as a separate post may gain better traction. My involvement here is to help extend the life and enjoyment of Acoustat loudspeakers. And regarding your second question about frequency response graphs, I do not have anything that is not already publicly available from published reviews. Furthermore, I have little faith in such graphs, as it is extremely difficult to obtain accurate in-room response from large area radiators. I am not aware that Acoustat ever published such information.
Andy,
That's very interesting, thank you for the analysis and guidance, much appreciated!
Okay, will do and I will report back with my findings.
Best regards,
Steve in NM
Someone mentioned that the XL was designed by Dick ( Richard Marsh ), did he work for Hafler at some point ?
Andy, et al.,
I have the interfaces open and have found several things from close visual inspection. The diaphragm wire connection to the output PC board on one speaker was badly degraded at its pin colar and just broke off when I tried to pull the pin out of the socket. I'll have to resolder that, easy. The HF attenuation resister (+2, 0, -2 dB) exposed windings are blue with oxidation. The third main difference is the audio input fuses are very different, and one looks like its element is barely intact.
Anyone have the schematic for the 1+1 with Medallion transformers? I've tried searching diyaudio.com, but its search engine is next to useless, apparently.
TIA
Steve in NM
I have the interfaces open and have found several things from close visual inspection. The diaphragm wire connection to the output PC board on one speaker was badly degraded at its pin colar and just broke off when I tried to pull the pin out of the socket. I'll have to resolder that, easy. The HF attenuation resister (+2, 0, -2 dB) exposed windings are blue with oxidation. The third main difference is the audio input fuses are very different, and one looks like its element is barely intact.
Anyone have the schematic for the 1+1 with Medallion transformers? I've tried searching diyaudio.com, but its search engine is next to useless, apparently.
TIA
Steve in NM
I wanted to thank you for your thoughts on this, please excuse how late I am doing so! I have decided that a plywood with veneer of choice would be best way to go. Do you agree?
**
As an aside, my interfaces (set of 2+2's and 1+1's) have been with Russ Knotts for a going over. Turned out, when I looked him up, he is close by to where I live, how great is that!? Drove them out to him and visited, just a great guy and a wealth of information. He is a bit older now, like all of us lol, and has not been as active with work but he is still kicking! He had some health issues he's been working on and he is on the mend.🙂
I have read here that upgrading the binding posts is a good thing, can anyone recommend what to use that isn't exorbitant? Would like to have Russ do that while he has them. Anything else while they are in his hands to consider? They're both red medallions.
Attached is the schematic for the MK121C. Note there is nothing different about the schematic for the Medallion transformers - they are different internally than the earlier non-Medallion transformer but are connected the same. However, the "C" designation indicates the improved HF primary circuit, which is shown on the schematic. The schematic covers all the models that used the MK121 interface. For your 2-panel Model 1+1, you'll want the LF transformer tap set to the RED position. Other positions (for 3 and 4 panel systems) will offer less bass boost, which you may prefer. There's no harm in trying other positions.
Failure of the connection at the pin plugs and hook terminals is not uncommon after many years of handling. After resoldering, a reinforcement of heat shrink tubing will help ensure the integrity of the connection.
Likewise, corrosion on the exposed winding of the HF Balance resistor is not uncommon. It can be cleaned with some fine emery paper.
Failure of the connection at the pin plugs and hook terminals is not uncommon after many years of handling. After resoldering, a reinforcement of heat shrink tubing will help ensure the integrity of the connection.
Likewise, corrosion on the exposed winding of the HF Balance resistor is not uncommon. It can be cleaned with some fine emery paper.
Not directly. I recall he might have had something to do with the "tuneability" (distortion null) of the XL feature and may have been compensated for his efforts. Not sure. Nevertheless, the XL series was still another evolutionary step from the original DH200. It was certainly not a brand-new design.