HH Scott , I had a feeling Mr Winer wasn't going to show up. Yeah Paul should narrate children's books when he retires at a hundred. What I would like to see is him do that show where he looks into the camera and see's us and calls out our names. Oh, wait, your too young to remember that aren't you?
@@SJMessinwithBoats1 Are you talking about Mr Rogers? Or Captain Kangaroo? I watched both of those, but don't remember that much from that age. I'll be 47 in April. I'm not that young, unfortunately.
Yeah, blew my mind, it was a lady and I was 3 or 4 years old, so 1965 or 1966. Dude, really thought it was real!! I was in Maryland, used to go crabbing on the Chesapeake. Slow day at Paul's place. Today😒
@@SJMessinwithBoats1 That's funny. You've got a great memory my man. I grew up in Newport RI. So I know all about going crabbing, and clamming. I'd still be going if I didn't have gout. Nothing like going out, and getting it yourself, then going home and cooking it up. It tastes way better, then when you buy it at the store
That's exactly why I have a Rythmik. For the price they simply can't be beat. And that Rythmik sub will probably match very well with your new speakers Paul ;)
i have a ton of Rythmik coils and have been playing with them in custom drivers , the design actually works very well , both can achieve very good results to where the design of driver , enclosure and placement become a larger aspect to getting desired results
I got an el cheapo el pipe-o - goes below 20Hz for less than $200 - www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjKk8X739jnAhXW7HMBHdFHDe8QFjAAegQIAxAB&url=http%3A%2F%2Fwww.firstwatt.com%2Fpdf%2Fart_elpipeo.pdf&usg=AOvVaw06mZA6XPqLqUGA0VFoMNL8
@@michaelbliss3337 I think they call sound below 20Hz infrasound. Although humans generally don't hear below that, if it is produced with enough intensity you will feel it. And so will your house and everything in it. Seismologists are the ultimate bass heads.. They look for earth bass way down to 1Hz and below for earthquake detection. So. If you're into earthquake movies or music then you'll be interested lol.
From @5:50 Paul will leave no doubt by telling you twice in less than 5 seconds that your phone has an accelerometer 😊 listening to Paul is always so pleasant because he is very spontaneous and natural.
Yeah, can you imagine Romper Room, Mr. Rogers, and the Captain all on the same set agreeing to how to present to all the little boys and girls a good educational haopy time? I heard your active port thing, now here's mine, Sealed box ok, then inside is a port to another chamber like an expansion chamber. That's it! That all I got! So the woofer is free to do what it wants and then as things get pressured it has the resistance of the port to the other chamber! Its a free flowing but not boomy, hopefully!
Servo subs work well with anything, including Magnepans. Magnepans require a little extra bass help, but that's ok, all speakers do, just a little more with Magnepans. I have two pairs of Maggies, and they work fine with a B+W ASW-750 12" sealed sub. However, I believe that a servo sub is theoretically "better" in many respects to a non-servo sub. Which Magnepans are you using?
Quite enjoyed this explanation of servo subs but it raised more questions for me than it answered... The accelerometer (or secondary coil as you mentioned) is obviously a laggong indicator... How do you use that feedback loop to adjust amplifier power if the motion you wanted to correct had already happened? Is it some kind of predictive logic or is it straightforward? Lets say a kick drum (or explosion in a movie) happens... Big inputs decaying down quickly... How does the servo avoid overcompensating?
If it happens with electricity, it is a physical system that moves at the speed of light, or very near it. So the measurement and correction happen nearly simultaneously.
You build what in control systems is called a predictor - a mathematical model that takes into account key parameters to allow predicting where the system (in our case speaker) will be in some point in the future if no changes are made to any inputs. eg take speaker cone position, velocity and acceleration along with mass and damping factor (Q) and create a predictive formula. This information is then used in an algorithm to adjust the current excitation or voltage applied to the speaker such that the future predicted error between predicted and desired position is reduced to zero, or near to it. This way undershoot and/or overshoot are vastly reduced.
I deal with servos every day because they position all the axes in my CNC machines. I have built servo systems, both electronic and purely mechanical. I understand them pretty well. In a servo speaker system where does the feedback go? Is there an amplifier in the servo speaker? Or does the servo system attenuate the signal from the main amp and then ask for more depending on the cone position? Following error in a servo system must be kept to a minimum so your speakers must be pretty stiff in positioning at the frequencies desired. Anyway, just curious, this kind of technical stuff really appeals to me. Eric
Yes, amplifier power is adjusted based on the servo feedback. I'm not an engineer but I would imagine that the signals are summed or subtracted to create the ideal amp signal.
@LD Blake Don't let Ethan catch you or it will be fifty lashings with home depot 16 gauge speaker wire while reciting the mantra all amplifiers sound the same.😦😜
Well I have 40 years experience with DIY Speakers. I will say this, and I'm sure people will call me out into a public debate. (hopefully) "Having an add on subwoofer is like putting big wheels and tires on a pickup truck and expecting it to be a win win situation"
Paul, since we are on topic for servo woofers, I have a pair of Infinity KAPPA 8 Reference speaker columns, and was wondering can it's 12 inch woofers/sub-woofers be modified in any way to be servo controlled for better response??
So how Yamaha maneged to do a servo system with only 2 wires going to the speaker box. like on my YST-C10? This little Yamaha mini component pushes tons of air and the little 3" subwoofer barely moves. Bass reaches faraway.
Great video as always. Thanks! Could you give us your opinion about the Yamaha YST II . I mean is this another way of making a servo woofer? And generally speaking does servo woofer sound "faster" than the non servo ones?
I remember I had a little subwoofer from...Mirage, I think it was. It had a long tube where all the air came out in the back, and when I played a heavy bass track it would blow so much air out that you could hear this muffler kind of whistle louder than the actual bass.
The input signal to the speaker, the voltage indicates how the amplitude is to vary with time. The transducer measures the actual motion generating an electrical signal that is compared to the input signal. The difference is distortion and the voice coil in a servo amplifier is driven by the negative difference between the two correcting for the dostortion. There are three generic types of motion sensors. Each has many ways to build them. The first one measures the actual position directly. It's called a strain gage. A second type is called a velocimeter. This type measures the change in position with time. Clearly it can't be directly compared to the input voltage, it's apples and oranges. The signal must first go.thtough a circuit called an integrator. It gets you back to position as a function of time. The third type is called an accelerometer. It measures the change in velocity as a function of time. It's signal must be integrated twice to.get to position as a function.of time.
Yeah but what about the idea I had of an active control system of controlling the pressure inside the cabinet. The cabinet can control the overhang automatically and you can reduce pressure automatically just by using the natural energy of the driver.
I don't really know how the corrections work, but I dont think an accelerometer is the best choice. An accelerometer measures acceleration and acceleration only. If it is not accelerating it outputs nothing. So if you are trying to get the current possition of the diaphram (which is what I assume you need), you will need to do some fancy math stuff to calculate the position based off of what the accelerometer has read over time. This is called an IMU and it works great for navigation in all sorts of vehicles including boats, planes, and even satelites. But for movemnt this high of frequency I highly doubt the accuracy you could get out of an IMU. I personally think you really should be using a laser or some other system to directly measure the position of the diaphram. I do think you could do the corrections in a way where it doesnt need to know the actuall position of the diaphram, just the acceleration, but I dont think it would be as accurate as if you knew the actuall postion. I am not saying the way it is already done is bad, but it could possibly be better. And once again I don't really know how the corrections work.
I used to love my dads AR towers in 1980, had a passive. But there is nothing great about it. I know Andrew does it but its a less than the best situation for top line.
Question.. What is the best home cinema/hi-fi sub out there.. Paul never mentions Paradigm.. JL Audio.. Velodyne.. All make pretty mean beasts. SVS another big hitter!
I enjoyed becoming knowledgeable about the topic., which made me happy not to have ever sensed I have a problem with my sub (JBL B-380 powered by a Sony TA-N80ES). It sounds right. I think the bigger problem for most folks is sub integration, since the sub is not treated as a channel but instead a crossover matter. Of course with stereo material it will always be a crossover matter, unless amplification makes use of DSP to extract a sub channel. And that's what I'd like to see, DSP added to stereo integrated amps and preamps to make integration of passive subs a cost/effective solution to the sub chaos we have now.
I keep watching these servo videos in the hope of finding out how this signal from the accelerometer actually does anything. Great you have this signal, now what? None of my amps have an accelerometer input, so what magic transpires between the accelerometer and the amp to make this timing correction happen?
The accelerometer generates a small voltage in response to movement. We take that voltage and integrate it in an integrator (an op amp with a capacitor in its feedback loop) to get acceleration. The output of that integrator is then fed into a difference amplifier that compares the input signal of the power amplifier with the output signal of the integrator (accelerometer). The difference between the two is then used to adjust the final output signal feeding the subwoofer amplifier. The result is what drives the woofer. There are no accelerometer "inputs" as you suggest. Typically these are closed loop systems.
@@Paulmcgowanpsaudio Thanks I think I've got it, the output of the integrator is then compared against the source signal, and small changes are made to the output signal to realign the driver to the amp signal in the form of a correction. That sounds like a lot of error correction processing going on in the back end. Would I be right in assuming that the servo woofer would typically be used with a plate amp where you can tap into and make the necessary signal changes? Could you make the necessary mods to a regular amp, or is it a too hard basket?
@@DodgyBrothersEngineering Yes, you have it exactly. In the servo amps we built for Genesis on the separate subwoofer it was all contained on a plate amplifier. For the original servo system found in the IRS, the accelerometer had its own cable that fed an external crossover box. In the Genesis 1 and other speakers with an external amplifier there were dedicated cables connecting the amps and servo system. Lastly, in the IRS Beta from Infinity, there was an external crossover box that required the addition of a user supplied external amplifier for the subs.
@@Paulmcgowanpsaudio Thanks again, sounds a little out of my electrical league to do a DIY on my upcoming 18" TC Sounds LMS Ultra 5400, 2 x 18" VMP PR's box. Hopefully the PR's lack of any real air resistance, along with a gigantic motor can keep it all under control. I'm driving it with a Crown IT9000 HD, so not that easy to do a servo conversion.
I have a Velodyne FSR-15 with a frozen woof-woof (and I'm not sure if there is anything else wrecked). It died while given to someone else, and they said it just died one day (not under abuse). AFAIK, there's nothing that can be done with it - fishing for any suggestions.
CHECK ENGINE I think it is because a small or large driver can oscillate to low frequencies. Also, I believe the strong neodymium magnets enabled the much small size.
Small drivers in a small space will compress the air, it helps that headphones are usually sealed. Put your phone in a shoe box and you'll get more bass, same principle. And the opposite is true with a large venue, that's why you will see multiple very large woofers stacked on stage.
Sometimes it seems like speakers have been invented to death, but all we really need are a new set of variables to work with. Here's one. A semi-active port. One woofer, dual voice coil. Second woofer where the passive radiator would go but driven by the unused voice coil of the first. Here's another. A woofer with a parabolic efficiency curve to counter that caused by the suspension.
@@SJMessinwithBoats1 As are many ported solutions in general. However if you impose some control over them including how the primary woofer is imposed upon by the box it seems like a more wholistic approach to porting. In other words use the output from the secondary coil to impart a fuller equation onto the port (would be passive element) It seems to me you should be able to get the advantages of a ported solution while spreading out the response without so much of the one-note-wonder effect. I long for and look forward to the return of the days where I might be able to go Wally Woodshop on it and find out myself. I also want to make a voice coil that couples more loosely at zero excursion than it does toward either extreme like some kind of stretch wound config.
Wow that's a lot! I have to go word for to try to understand. I'm just two Pa drivers inverted and getting an omnidirectional pattern and I can't get off it and jammed all summer, many people heard it and many enjoyed.
@@InsideOfMyOwnMind Yeah, a secondary coil? Do you build woofers from scratch? I think when you try something new that you have to have something to present because words and final product is two different things most the time. I have my best guess going on and I will start with the final working prototype. I'm looking at spring with my design.
@@InsideOfMyOwnMind I understand what your saying, for me , I use my system outside a lot and and small main driver just doesn't have the balance in proportion that the EV 15 driver does. My expermentation accidently lead me to reducing the recommended box size in half and mounting the driver face down in the shallow box. All of a sudden,. Drums hit hard and bass was so pleasing as nothing much below 50 hz. It only needed a few db up around 5 k and 8 k. But l have Phillips dome mids that match the output of the LF 15in driver. I just got a mic but you can actually hear what I'm talking about now. Would you like to hear? I can post a video this week.?
@@SJMessinwithBoats1 Granted the output from dvc coil2 by itself won't do much to the 2nd driver. My line of thinking was you could extract the signal from dvc coil2 to impart the unwanted characteristics onto the 2nd driver which remember used to be completely passive. You could put some amplification between dvc coil2 and the I guess you could now call it a pseudo-active radiator. Play around with phase, frequency response and levels to "port" the box according to what the music requires based upon the errors between the native input and the output of dvc coil2. This should impart the box as reflected into the dvc driver as well as dvc shortcommings onto the port. This should give you some stuff to play with that you didn't have before. Be careful with the gain so that inherent aberrations don't flip the feedback polarity and end the little Jenga blocks game that we're playing. You may have to have some pretty tightly defined (high order)polls in the network of this new part of the signal path to prevent it..
I went along with all of that ... but I have to say this .... servo systems are and always will be a kind of necessary evil to correct another unavoidable evil so produced by inferior loudspeakers. I STILL maintain that a LF driver with a very stiff and low Mms ( diaphragm mass) also with a low Vas ( restoring force given by a given volume of air ) mounted in a well controlled potted enclosure will outperform any servo system ! The amplifier must have a very high damping factor and the bass driver must equally have a very high Bl ... PS audio should seriously consider this in their new speaker designs ...
He's in love with those servos because of Arnie. He knows not of what he does other than following Arnie because Arnie pulled it off before. ok, if had his system I would go all active, go paper or carbon, I suppose for the woofers and have an amp channel for every last driver. 25 wpc on each driver. But in the end its just too big to take home. I also feel that those ribbon mids are most likely to "machine like" sounding. He's got those crossed too low. Its just a full on mess in my thinking. You don't have to like or dislike. Just airing out. Hope I'm not bothering, its pertaining to your satatement. You have been so focused on that IRS!!
Brian David Loveless ~ yes there is an element of truth in what you say about Arnie... I thought of that too. To suddenly set out to manufacture high end speaker systems from scratch requires a lot of experience ( without falling back on copying previous associated designs ) PS Audio must adopt broader thinking in order to pull this off otherwise people will assume they are just reinventing Infinity speakers . The secret to a really good speaker system lies in the quality of the drivers .. I have already seen one woofer that Paul was using .. I must say one thing it did look very impressive.. good general specs ( I'd love to see the full set of Theile-Small parameters) .. so let's sit back and wait for the first production models to arrive !
i think the biggest reason why ps audio is going with servo woofers is that they want the build the subwoofer in the cabinet with the main speaker, some serious eq have to be done to make this sound good, paul knows that subwoofer placement and speaker placement is not the same for best result. be he want to make a simple all in one product. but then my fears is that no one wants it, people that want proper bass want a separate subwoofer and people that dont want subwoofer will have one built into the tower speakers......
Janina Palmer, when you say "potted" maybe "ported" or plotted? What is the surround on this desired driver in your thoughts? Doesn't voice coil size have more to do with power handling? 4 inch seems large. My puppys are just 2.5 inch and that seems large enough. I'm not sure what bl is, looks like I have studying to do. I did come up with a pleasing solution this summer with combining the DL15x with a 10 inch softly sprung rubber surround drier. Guaranteed phase correct. Most likely would never fly in the commercial market, but that's not what I'm after. I have no plans for money making. Only to live out my grey years having a good musical time.
I think I'm going to unsubscribe because of this..Paul has gone over all of these points before and many other questions it's just repetition, he's getting old dear love him, and he wants an easy life so why not just answer again the questions of the past instead of answering something new..Does he just do this because he couldn't be bothered or is his memory getting a little well less so. I'm really done here and it's sad but I really couldn't be bothered
This is the first time that I have felt compelled to comment on something as unkind, self- indulgent, and just plain low class as your post. Did it ever occur to you that the reason Paul does repeat some subjects is because he does not want his viewers to feel that he is ignoring them? Paul is something that you most certainly are not, namely a gentleman and a kind person. Please, do us all a favor, UNSUBSCRIBE!
@@galenzellars6971 Another idiot if you read my comment it is not unkind but factual...A pity this site has many stupid people including the idiot below To The Max
Who else thinks Paul should write, and narrate a children's book? "The Little Power Amplifier That Could" 🤣🤣🤣
HH Scott , I had a feeling Mr Winer wasn't going to show up. Yeah Paul should narrate children's books when he retires at a hundred. What I would like to see is him do that show where he looks into the camera and see's us and calls out our names. Oh, wait, your too young to remember that aren't you?
@@SJMessinwithBoats1 Are you talking about Mr Rogers? Or Captain Kangaroo? I watched both of those, but don't remember that much from that age. I'll be 47 in April. I'm not that young, unfortunately.
Yeah, blew my mind, it was a lady and I was 3 or 4 years old, so 1965 or 1966. Dude, really thought it was real!! I was in Maryland, used to go crabbing on the Chesapeake.
Slow day at Paul's place. Today😒
@@SJMessinwithBoats1 That's funny. You've got a great memory my man. I grew up in Newport RI. So I know all about going crabbing, and clamming. I'd still be going if I didn't have gout. Nothing like going out, and getting it yourself, then going home and cooking it up. It tastes way better, then when you buy it at the store
@@amb3cog Oh Hell, I remember Romper Room.
That's exactly why I have a Rythmik. For the price they simply can't be beat. And that Rythmik sub will probably match very well with your new speakers Paul ;)
i have a ton of Rythmik coils and have been playing with them in custom drivers , the design actually works very well , both can achieve very good results to where the design of driver , enclosure and placement become a larger aspect to getting desired results
I have a Rythmik sub. It’s great, especially for the cost. Goes below 20Hz for less than $1k.
I got an el cheapo el pipe-o - goes below 20Hz for less than $200 - www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjKk8X739jnAhXW7HMBHdFHDe8QFjAAegQIAxAB&url=http%3A%2F%2Fwww.firstwatt.com%2Fpdf%2Fart_elpipeo.pdf&usg=AOvVaw06mZA6XPqLqUGA0VFoMNL8
@@garethsmith7628
This would look awesome in my living room!
Once you go Rythmik, you never go back to anything else!
can you hear below 20Hz?
@@michaelbliss3337 I think they call sound below 20Hz infrasound. Although humans generally don't hear below that, if it is produced with enough intensity you will feel it. And so will your house and everything in it.
Seismologists are the ultimate bass heads.. They look for earth bass way down to 1Hz and below for earthquake detection.
So. If you're into earthquake movies or music then you'll be interested lol.
From @5:50 Paul will leave no doubt by telling you twice in less than 5 seconds that your phone has an accelerometer 😊 listening to Paul is always so pleasant because he is very spontaneous and natural.
I would imagine that there must be a frequency that the accelerometer starts to become ineffective.
Yeah, can you imagine Romper Room, Mr. Rogers, and the Captain all on the same set agreeing to how to present to all the little boys and girls a good educational haopy time?
I heard your active port thing, now here's mine, Sealed box ok, then inside is a port to another chamber like an expansion chamber.
That's it! That all I got!
So the woofer is free to do what it wants and then as things get pressured it has the resistance of the port to the other chamber!
Its a free flowing but not boomy, hopefully!
servo subs a good fit for magnapans?
I hear the open baffle subs are a good fit for Maggies.
Servo subs work well with anything, including Magnepans. Magnepans require a little extra bass help, but that's ok, all speakers do, just a little more with Magnepans. I have two pairs of Maggies, and they work fine with a B+W ASW-750 12" sealed sub. However, I believe that a servo sub is theoretically "better" in many respects to a non-servo sub.
Which Magnepans are you using?
Channeling Borat here Paul,
I Am Power Amplifier, Look at my powerful chair, I am King of Castle!
Just another form of a feedback loop in an amplifier to reduce distortion. Only further down the food chain.
Quite enjoyed this explanation of servo subs but it raised more questions for me than it answered... The accelerometer (or secondary coil as you mentioned) is obviously a laggong indicator... How do you use that feedback loop to adjust amplifier power if the motion you wanted to correct had already happened? Is it some kind of predictive logic or is it straightforward? Lets say a kick drum (or explosion in a movie) happens... Big inputs decaying down quickly... How does the servo avoid overcompensating?
If it happens with electricity, it is a physical system that moves at the speed of light, or very near it. So the measurement and correction happen nearly simultaneously.
You build what in control systems is called a predictor - a mathematical model that takes into account key parameters to allow predicting where the system (in our case speaker) will be in some point in the future if no changes are made to any inputs. eg take speaker cone position, velocity and acceleration along with mass and damping factor (Q) and create a predictive formula.
This information is then used in an algorithm to adjust the current excitation or voltage applied to the speaker such that the future predicted error between predicted and desired position is reduced to zero, or near to it. This way undershoot and/or overshoot are vastly reduced.
I deal with servos every day because they position all the axes in my CNC machines. I have built servo systems, both electronic and purely mechanical. I understand them pretty well. In a servo speaker system where does the feedback go? Is there an amplifier in the servo speaker? Or does the servo system attenuate the signal from the main amp and then ask for more depending on the cone position? Following error in a servo system must be kept to a minimum so your speakers must be pretty stiff in positioning at the frequencies desired. Anyway, just curious, this kind of technical stuff really appeals to me.
Eric
Yes, amplifier power is adjusted based on the servo feedback. I'm not an engineer but I would imagine that the signals are summed or subtracted to create the ideal amp signal.
People need to check out Winers home theatre setup....all will become clear.
@LD Blake LD what are you doing over here? Is watching snake oil video's one of your guilty pleasures?😝
@LD Blake Don't let Ethan catch you or it will be fifty lashings with home depot 16 gauge speaker wire while reciting the mantra all amplifiers sound the same.😦😜
@@mag-wp6yt And, a Picasso and Monet are just paint...
Yeah man I did and looks like a dogs breakfast, but liked the projector screen
Well I have 40 years experience with DIY Speakers. I will say this, and I'm sure people will call me out into a public debate. (hopefully) "Having an add on subwoofer is like putting big wheels and tires on a pickup truck and expecting it to be a win win situation"
Paul, since we are on topic for servo woofers, I have a pair of Infinity KAPPA 8 Reference speaker columns, and was wondering can it's 12 inch woofers/sub-woofers be modified in any way to be servo controlled for better response??
So how Yamaha maneged to do a servo system with only 2 wires going to the speaker box.
like on my YST-C10?
This little Yamaha mini component pushes tons of air and the little 3" subwoofer barely moves.
Bass reaches faraway.
Great video as always. Thanks! Could you give us your opinion about the Yamaha YST II . I mean is this another way of making a servo woofer? And generally speaking does servo woofer sound "faster" than the non servo ones?
I remember I had a little subwoofer from...Mirage, I think it was. It had a long tube where all the air came out in the back, and when I played a heavy bass track it would blow so much air out that you could hear this muffler kind of whistle louder than the actual bass.
Port noise is what it's called
@@adamtolbert3279 Oh, okay. Not a big fan.
thegrimyeaper ~ that's because the port tube was to narrow and probably wasn't flared at both ends
The input signal to the speaker, the voltage indicates how the amplitude is to vary with time. The transducer measures the actual motion generating an electrical signal that is compared to the input signal. The difference is distortion and the voice coil in a servo amplifier is driven by the negative difference between the two correcting for the dostortion.
There are three generic types of motion sensors. Each has many ways to build them. The first one measures the actual position directly. It's called a strain gage. A second type is called a velocimeter. This type measures the change in position with time. Clearly it can't be directly compared to the input voltage, it's apples and oranges. The signal must first go.thtough a circuit called an integrator. It gets you back to position as a function of time. The third type is called an accelerometer. It measures the change in velocity as a function of time. It's signal must be integrated twice to.get to position as a function.of time.
Yeah but what about the idea I had of an active control system of controlling the pressure inside the cabinet. The cabinet can control the overhang automatically and you can reduce pressure automatically just by using the natural energy of the driver.
Nice one Paul.
I don't really know how the corrections work, but I dont think an accelerometer is the best choice. An accelerometer measures acceleration and acceleration only. If it is not accelerating it outputs nothing. So if you are trying to get the current possition of the diaphram (which is what I assume you need), you will need to do some fancy math stuff to calculate the position based off of what the accelerometer has read over time. This is called an IMU and it works great for navigation in all sorts of vehicles including boats, planes, and even satelites. But for movemnt this high of frequency I highly doubt the accuracy you could get out of an IMU. I personally think you really should be using a laser or some other system to directly measure the position of the diaphram.
I do think you could do the corrections in a way where it doesnt need to know the actuall position of the diaphram, just the acceleration, but I dont think it would be as accurate as if you knew the actuall postion.
I am not saying the way it is already done is bad, but it could possibly be better. And once again I don't really know how the corrections work.
What is that power amplifier is it a pass labs?
The next logical question will be on passive radiators...pros and cons to relieving sealed sub box pressures thus sub inertia?
I used to love my dads AR towers in 1980, had a passive. But there is nothing great about it. I know Andrew does it but its a less than the best situation for top line.
Question.. What is the best home cinema/hi-fi sub out there.. Paul never mentions Paradigm.. JL Audio.. Velodyne.. All make pretty mean beasts. SVS another big hitter!
Funk Audio, Seaton Sound, JTR, JL Audio, Deep Sea Sound, Rythmik, HSU, depending on output/size/budget weight needs.
Cool information
"The problems we face with woofers". LMAO!
Philips did it ?
I enjoyed becoming knowledgeable about the topic., which made me happy not to have ever sensed I have a problem with my sub (JBL B-380 powered by a Sony TA-N80ES). It sounds right. I think the bigger problem for most folks is sub integration, since the sub is not treated as a channel but instead a crossover matter. Of course with stereo material it will always be a crossover matter, unless amplification makes use of DSP to extract a sub channel. And that's what I'd like to see, DSP added to stereo integrated amps and preamps to make integration of passive subs a cost/effective solution to the sub chaos we have now.
I keep watching these servo videos in the hope of finding out how this signal from the accelerometer actually does anything. Great you have this signal, now what? None of my amps have an accelerometer input, so what magic transpires between the accelerometer and the amp to make this timing correction happen?
The accelerometer generates a small voltage in response to movement. We take that voltage and integrate it in an integrator (an op amp with a capacitor in its feedback loop) to get acceleration. The output of that integrator is then fed into a difference amplifier that compares the input signal of the power amplifier with the output signal of the integrator (accelerometer). The difference between the two is then used to adjust the final output signal feeding the subwoofer amplifier. The result is what drives the woofer. There are no accelerometer "inputs" as you suggest. Typically these are closed loop systems.
@@Paulmcgowanpsaudio Thanks I think I've got it, the output of the integrator is then compared against the source signal, and small changes are made to the output signal to realign the driver to the amp signal in the form of a correction. That sounds like a lot of error correction processing going on in the back end. Would I be right in assuming that the servo woofer would typically be used with a plate amp where you can tap into and make the necessary signal changes? Could you make the necessary mods to a regular amp, or is it a too hard basket?
@@DodgyBrothersEngineering Yes, you have it exactly. In the servo amps we built for Genesis on the separate subwoofer it was all contained on a plate amplifier. For the original servo system found in the IRS, the accelerometer had its own cable that fed an external crossover box. In the Genesis 1 and other speakers with an external amplifier there were dedicated cables connecting the amps and servo system. Lastly, in the IRS Beta from Infinity, there was an external crossover box that required the addition of a user supplied external amplifier for the subs.
@@Paulmcgowanpsaudio Thanks again, sounds a little out of my electrical league to do a DIY on my upcoming 18" TC Sounds LMS Ultra 5400, 2 x 18" VMP PR's box. Hopefully the PR's lack of any real air resistance, along with a gigantic motor can keep it all under control. I'm driving it with a Crown IT9000 HD, so not that easy to do a servo conversion.
I have a Velodyne FSR-15 with a frozen woof-woof (and I'm not sure if there is anything else wrecked). It died while given to someone else, and they said it just died one day (not under abuse). AFAIK, there's nothing that can be done with it - fishing for any suggestions.
Is it a Watt or a Watt Puppy behind you maybe?
Curious about that as well! Pass designs are so far from PS’ ones. I wonder why there is what looks to be a pass in the background
is your audio book finished? thanks Paul
The writing of it yes, and now we're finishing the audio reading and the publishing of it. I really hope we can have it available in January.
Criticizing Houston and Dallas while defending Austin? Very interesting.
How does a servo subwoofer motor work?
No difference in the motor.
How can my headphones produce low frequencies when they are so small ( the headphone )
CHECK ENGINE I think it is because a small or large driver can oscillate to low frequencies. Also, I believe the strong neodymium magnets enabled the much small size.
Small drivers in a small space will compress the air, it helps that headphones are usually sealed. Put your phone in a shoe box and you'll get more bass, same principle. And the opposite is true with a large venue, that's why you will see multiple very large woofers stacked on stage.
Bad to the bone speaker piled up behind him.
Austin? Lol, Heck no! Too Lib for me
Paul power amp animator
Sometimes it seems like speakers have been invented to death, but all we really need are a new set of variables to work with.
Here's one. A semi-active port. One woofer, dual voice coil. Second woofer where the passive radiator would go but driven by the unused voice coil of the first.
Here's another.
A woofer with a parabolic efficiency curve to counter that caused by the suspension.
@@SJMessinwithBoats1 As are many ported solutions in general. However if you impose some control over them including how the primary woofer is imposed upon by the box it seems like a more wholistic approach to porting. In other words use the output from the secondary coil to impart a fuller equation onto the port (would be passive element) It seems to me you should be able to get the advantages of a ported solution while spreading out the response without so much of the one-note-wonder effect.
I long for and look forward to the return of the days where I might be able to go Wally Woodshop on it and find out myself.
I also want to make a voice coil that couples more loosely at zero excursion than it does toward either extreme like some kind of stretch wound config.
Wow that's a lot! I have to go word for to try to understand. I'm just two Pa drivers inverted and getting an omnidirectional pattern and I can't get off it and jammed all summer, many people heard it and many enjoyed.
@@InsideOfMyOwnMind Yeah, a secondary coil? Do you build woofers from scratch? I think when you try something new that you have to have something to present because words and final product is two different things most the time. I have my best guess going on and I will start with the final working prototype. I'm looking at spring with my design.
@@InsideOfMyOwnMind I understand what your saying, for me , I use my system outside a lot and and small main driver just doesn't have the balance in proportion that the EV 15 driver does. My expermentation accidently lead me to reducing the recommended box size in half and mounting the driver face down in the shallow box. All of a sudden,. Drums hit hard and bass was so pleasing as nothing much below 50 hz. It only needed a few db up around 5 k and 8 k. But l have Phillips dome mids that match the output of the
LF 15in driver. I just got a mic but you can actually hear what I'm talking about now. Would you like to hear? I can post a video this week.?
@@SJMessinwithBoats1 Granted the output from dvc coil2 by itself won't do much to the 2nd driver. My line of thinking was you could extract the signal from dvc coil2 to impart the unwanted characteristics onto the 2nd driver which remember used to be completely passive. You could put some amplification between dvc coil2 and the I guess you could now call it a pseudo-active radiator. Play around with phase, frequency response and levels to "port" the box according to what the music requires based upon the errors between the native input and the output of dvc coil2. This should impart the box as reflected into the dvc driver as well as dvc shortcommings onto the port. This should give you some stuff to play with that you didn't have before. Be careful with the gain so that inherent aberrations don't flip the feedback polarity and end the little Jenga blocks game that we're playing. You may have to have some pretty tightly defined (high order)polls in the network of this new part of the signal path to prevent it..
I don't wanna be an asshole, but how come a company that specializes in high end audio has such terrible voice recording quality on their videos?
I went along with all of that ... but I have to say this .... servo systems are and always will be a kind of necessary evil to correct another unavoidable evil so produced by inferior loudspeakers.
I STILL maintain that a LF driver with a very stiff and low Mms ( diaphragm mass) also with a low Vas ( restoring force given by a given volume of air ) mounted in a well controlled potted enclosure will outperform any servo system ! The amplifier must have a very high damping factor and the bass driver must equally have a very high Bl ... PS audio should seriously consider this in their new speaker designs ...
He's in love with those servos because of Arnie. He knows not of what he does other than following Arnie because Arnie pulled it off before.
ok, if had his system I would go all active, go paper or carbon, I suppose for the woofers and have an amp channel for every last driver. 25 wpc on each driver. But in the end its just too big to take home. I also feel that those ribbon mids are most likely to "machine like" sounding. He's got those crossed too low. Its just a full on mess in my thinking.
You don't have to like or dislike. Just airing out. Hope I'm not bothering, its pertaining to your satatement. You have been so focused on that IRS!!
Brian David Loveless ~ yes there is an element of truth in what you say about Arnie... I thought of that too.
To suddenly set out to manufacture high end speaker systems from scratch requires a lot of experience ( without falling back on copying previous associated designs ) PS Audio must adopt broader thinking in order to pull this off otherwise people will assume they are just reinventing Infinity speakers .
The secret to a really good speaker system lies in the quality of the drivers .. I have already seen one woofer that Paul was using .. I must say one thing it did look very impressive.. good general specs ( I'd love to see the full set of Theile-Small parameters) .. so let's sit back and wait for the first production models to arrive !
i think the biggest reason why ps audio is going with servo woofers is that they want the build the subwoofer in the cabinet with the main speaker, some serious eq have to be done to make this sound good, paul knows that subwoofer placement and speaker placement is not the same for best result. be he want to make a simple all in one product. but then my fears is that no one wants it, people that want proper bass want a separate subwoofer and people that dont want subwoofer will have one built into the tower speakers......
@@janinapalmer8368 🆗🆒
Janina Palmer, when you say "potted" maybe "ported" or plotted?
What is the surround on this desired driver in your thoughts? Doesn't voice coil size have more to do with power handling? 4 inch seems large. My puppys are just 2.5 inch and that seems large enough. I'm not sure what bl is, looks like I have studying to do. I did come up with a pleasing solution this summer with combining the DL15x with a 10 inch softly sprung rubber surround drier. Guaranteed phase correct. Most likely would never fly in the commercial market, but that's not what I'm after. I have no plans for money making. Only to live out my grey years having a good musical time.
I think I'm going to unsubscribe because of this..Paul has gone over all of these points before and many other questions it's just repetition, he's getting old dear love him, and he wants an easy life so why not just answer again the questions of the past instead of answering something new..Does he just do this because he couldn't be bothered or is his memory getting a little well less so. I'm really done here and it's sad but I really couldn't be bothered
unsubscribe already and less of the farewell speech.
@@mag-wp6yt I dislike stupidity and your are.....
This is the first time that I have felt compelled to comment on something as unkind, self- indulgent, and just plain low class as your post. Did it ever occur to you that the reason Paul does repeat some subjects is because he does not want his viewers to feel that he is ignoring them? Paul is something that you most certainly are not, namely a gentleman and a kind person. Please, do us all a favor, UNSUBSCRIBE!
You're an idiot...good riddance
@@galenzellars6971 Another idiot if you read my comment it is not unkind but factual...A pity this site has many stupid people including the idiot below To The Max