I already have the MK121C interface with the AirMod. I just wondered why replace a fuse with a resistor on the primary of the HV transformer?
In that case, why not ask the man to whom you paid money for this modification? Having paid for it, you deserve an explanation. I won't attempt to figure out what is being done here, and quite frankly, almost all aftermarket mods I've seen do nothing or actually degrade the performance. I'm NOT saying this is one of those cases. It's your money and you take your chances buying a modification without an explanation.
Apologies didn't realize it would be a problem asking. I bought the speakers with the interfaces already completed. The guy who did the mods is now retired and not taking questions . I guess no answer.
No problem, didn't realize you bought the mod second-hand. Since I don't know what was done, I can't begin to comment on it. What do YOU think of the mod, listening-wise?
Hello to Andy Szabo the @AcoustatAnswerMan
It’s a great honor to get the opportunity to directly speak with a designer of these amazing Acoustat speakers!
I was fortunate to pick up a pair of Spectra 3’s which I think sound amazing and know you are were one of the designers. If you have the time I have some questions for you.
Unfortunately these speakers make the ultimate scratching posts for my cats. Do you think if I wrap some plastic spikes around the speakers like these that it will affect the sound?
My next question is about the high and low crossovers all the speakers. Do you ever recommend disabling either of them? Is biamping required to do so? With or without using the crossovers do you think that biamping can improve the sound? I know that people say to use an active crossover but also know that is not easy to implement properly. I’m using a Hafler 500 high wattage amp that I have heard is stable down to two ohms. If I were to biamp then I believe I would choice to use an additional Hafler 500. I could even use four as monoblocks to biamp the two speakers but assume that would be overkill.
My last question is about using an external sub. Do you think it improves the sound and if it does is it best to switch off the Spectra sub or leave it running? I realize the answer may be different for stereo music vs surround and the LFE channel.
I greatly appreciate if you get the time to provide your input on these things! Thanks.
It’s a great honor to get the opportunity to directly speak with a designer of these amazing Acoustat speakers!
I was fortunate to pick up a pair of Spectra 3’s which I think sound amazing and know you are were one of the designers. If you have the time I have some questions for you.
Unfortunately these speakers make the ultimate scratching posts for my cats. Do you think if I wrap some plastic spikes around the speakers like these that it will affect the sound?
My next question is about the high and low crossovers all the speakers. Do you ever recommend disabling either of them? Is biamping required to do so? With or without using the crossovers do you think that biamping can improve the sound? I know that people say to use an active crossover but also know that is not easy to implement properly. I’m using a Hafler 500 high wattage amp that I have heard is stable down to two ohms. If I were to biamp then I believe I would choice to use an additional Hafler 500. I could even use four as monoblocks to biamp the two speakers but assume that would be overkill.
My last question is about using an external sub. Do you think it improves the sound and if it does is it best to switch off the Spectra sub or leave it running? I realize the answer may be different for stereo music vs surround and the LFE channel.
I greatly appreciate if you get the time to provide your input on these things! Thanks.
I doubt the proposed plastic spikes would have much effect on the sound. The effects on appearance would be cat-istrophic, pun-intended.
If I remember correctly, the original Spectra 3 has the ability to have the woofer powered either by the main amplifier, or from a separate amplifier. Clearly the latter arrangement would have some advantages. This would be using the internal passive crossovers already in the speaker.
I generally don't recommend bridged amplifiers for Acoustat speakers. When you bridge an amplifier, each channel is presented with only half the load impedance. Since the speaker is already very low impedance at some frequencies, this presents a very difficult load. In addition, I don't feel there is much advantage in using more than 250 watts per channel, and one runs the risk of damage from overdriving. Therefore, using two stereo amps would be my recommended best practice.
If I remember correctly, the original Spectra 3 has the ability to have the woofer powered either by the main amplifier, or from a separate amplifier. Clearly the latter arrangement would have some advantages. This would be using the internal passive crossovers already in the speaker.
I generally don't recommend bridged amplifiers for Acoustat speakers. When you bridge an amplifier, each channel is presented with only half the load impedance. Since the speaker is already very low impedance at some frequencies, this presents a very difficult load. In addition, I don't feel there is much advantage in using more than 250 watts per channel, and one runs the risk of damage from overdriving. Therefore, using two stereo amps would be my recommended best practice.
Thanks for your input! The appearance will be better than the torn to hell look, ha.
There are high and low crossovers that can be switched on or off. Are there any bias adjustments to be made on this model? Can a subwoofer pair well for stereo and surround sound?
There are high and low crossovers that can be switched on or off. Are there any bias adjustments to be made on this model? Can a subwoofer pair well for stereo and surround sound?
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Re post 3396
If you study the "air.jpg" photo carefully, you'll see that the fuses are intact and there's a pair of black wires going from them to the high voltage Transformer. The diode and the resistor coming off the right side of them feed the blue wires going towards the rear in the picture, probably to an LED.
Re post 3396
If you study the "air.jpg" photo carefully, you'll see that the fuses are intact and there's a pair of black wires going from them to the high voltage Transformer. The diode and the resistor coming off the right side of them feed the blue wires going towards the rear in the picture, probably to an LED.
Anyone biamp Spectras using an active crossover opposed to the passive one built into the speakers?
I have a pair of model 3's that I use with a pair of stereo subs. I actively biamp with a dsp crossover to feed the low frequencies to the subs, those above 80Hz to the Acoustats. Not sure what you mean about the "passive one built into the speakers"- if you mean the Acoustats with a cone bass driver or those with a built it passive crossover for a sub, I think the use of an external crossover for the bass frequencies would be easy to facilitate. If you are referring to the transformer network used to shunt different frequencies to different panel sections in the Spectra panels, I doubt that is possible with an active external crossover.
@cab
Thanks for your input. My Spectra 3 have both a high and low passive crossover which can be bypassed. My thought was that having a basic active crossover to match the same frequencies would allow the amp more power but I have a beefy amp and any extra load of the passive crossover is probably minimal anyway.
If I had the proper skills to EQ then I would use a DSP to fine tune all the frequencies.
Thanks for your input. My Spectra 3 have both a high and low passive crossover which can be bypassed. My thought was that having a basic active crossover to match the same frequencies would allow the amp more power but I have a beefy amp and any extra load of the passive crossover is probably minimal anyway.
If I had the proper skills to EQ then I would use a DSP to fine tune all the frequencies.
@AcoustatAnswerMan A quick question-
Are the Spectra panels uni-directional? What I mean is, do they have a front/back, top/bottom, or can they be installed in any orientation? I ask because I am reconstructing a set of frames for my Spectra 6600 panels and would like to mount two of the panels back to front from the original orientation so that all the bias wires exit the panels facing the inside of the frame. I would remove the felt pad on the "back", flip the panel, remount the felt pad on the new "back". I want to be able to run the bias wires from all the panels down the two center vertical supports. Any issue with flipping two of the panels back to front?
Thanks as always for your time.
Are the Spectra panels uni-directional? What I mean is, do they have a front/back, top/bottom, or can they be installed in any orientation? I ask because I am reconstructing a set of frames for my Spectra 6600 panels and would like to mount two of the panels back to front from the original orientation so that all the bias wires exit the panels facing the inside of the frame. I would remove the felt pad on the "back", flip the panel, remount the felt pad on the new "back". I want to be able to run the bias wires from all the panels down the two center vertical supports. Any issue with flipping two of the panels back to front?
Thanks as always for your time.
@AcoustatAnswerMan or anyone with input
One of my Spectra 3’s is intermittently crackling and going muffled but then goes back to regular sound and volume. I have ruled out the speaker wire connections and amplifier. Any feedback from is appreciated!
One of my Spectra 3’s is intermittently crackling and going muffled but then goes back to regular sound and volume. I have ruled out the speaker wire connections and amplifier. Any feedback from is appreciated!
Check Bias wire and the 4 other stator wire connections are connected to the Interface PCB.
Be careful - make sure interface is unplugged from amp and power outlet, and stator wires are shorted to ground - so no voltage on panels...
Be careful - make sure interface is unplugged from amp and power outlet, and stator wires are shorted to ground - so no voltage on panels...
@john65b
Thanks for your input! Can you please give me info on how to short the stator wires to ground? How do I check the bias wire and stator wires are connected to the interface PCB? I would think if they weren’t all connected then I wouldn’t get the full sound at all but I may be incorrect. Thanks again!
Thanks for your input! Can you please give me info on how to short the stator wires to ground? How do I check the bias wire and stator wires are connected to the interface PCB? I would think if they weren’t all connected then I wouldn’t get the full sound at all but I may be incorrect. Thanks again!
Unplug power and amplifier to interface. Open interface, you will see five wires from panels to PCB - the red wire is bias, Carefully pull red wire out of its socket and touch it to the interface metal case. You may see a spark. Once finished, return to its socket. Do the same for all five wires one at a time.. Do not touch the wire tips as you will get a nice shock.
In its basic form, the Acoustat panel does not have a front or rear, or top or bottom. The only thing that determines “front” and “rear” is the position of the felt blocks, and the position of the bias wire attachment. Therefore, it is possible to move the felt blocks to the other side of the panel to reverse the orientation front-to-back.
I’m not sure I understand why you need to reverse some of the panels front-to-back, as it seems you could accomplish your goals by merely reversing top-to-bottom, without messing with the felt blocks. But perhaps I don’t fully understand what configuration you are attempting.
Of course, if you do reverse front-to-back, this will also reverse the wiring of the front and rear stators, so wire accordingly.