Lewinski,
Of course I look at all the references posted here, yours included. Keep it up. Yes I plan on doing something commercial, something I have been working towards for a long time since leaving the Pro-audio side of things with PA designs. That does not mean that all this information is not for the diy person, it is here for free exchange of anything that is posted.
Vacuphile,
I understand the issue of using a 16bit limit to control volume, that was discussed and shredded over in the Blowtorch thread for days.
Overkill,
Thanks for keeping things in perspective, I agree that to ignore digital at this point in time would be silly, we aren't taking about the early attempts with 8bit chips trying to do audio. The ESS site is one I have looked at myself multiple times. It would be simple to just use one of the dac implementation that has a 2v output, I'm sure you know which one I am talking about, but I think things need to move a bit farther along to do this to a great level. I just wish I had half of your understanding of all of this, I will get there but it will take some time. You have set the path that I am going to follow. Perhaps some day someone will have a system using both of our designs in combination.
ps. A friend and he is not the first told me to just take my speaker designs and tech and just sell it to someone else, I just can't do it. I really believe in what I am doing, I need to finish this for my soul, I don't want to see it corrupted by those companies who would be interested.
Of course I look at all the references posted here, yours included. Keep it up. Yes I plan on doing something commercial, something I have been working towards for a long time since leaving the Pro-audio side of things with PA designs. That does not mean that all this information is not for the diy person, it is here for free exchange of anything that is posted.
Vacuphile,
I understand the issue of using a 16bit limit to control volume, that was discussed and shredded over in the Blowtorch thread for days.
Overkill,
Thanks for keeping things in perspective, I agree that to ignore digital at this point in time would be silly, we aren't taking about the early attempts with 8bit chips trying to do audio. The ESS site is one I have looked at myself multiple times. It would be simple to just use one of the dac implementation that has a 2v output, I'm sure you know which one I am talking about, but I think things need to move a bit farther along to do this to a great level. I just wish I had half of your understanding of all of this, I will get there but it will take some time. You have set the path that I am going to follow. Perhaps some day someone will have a system using both of our designs in combination.
ps. A friend and he is not the first told me to just take my speaker designs and tech and just sell it to someone else, I just can't do it. I really believe in what I am doing, I need to finish this for my soul, I don't want to see it corrupted by those companies who would be interested.
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Good for the soul
Hi Stephen,
I totally empathise with you are seeing your core ideas developed into a finished system....when that day comes it will be beautiful!
There are several good options on the DAC front, flagship ESS and AKM DAC's and A to D convertors are all very good indeed.
Also given another 6 months or so R&D I think the R2R board from Soren could be a very good option....It eventually will be able to offer some crossover / Eq functions as well as DAC. It wont have huge number crunching ability but will offer a very low cost way into high end active systems.
On power amplifiers, N Core for bass and First One for mid / top.
On power supplies I have two strong preferences :
(1) Use globally certified high performance switch mode supplies like Hypex.
(2) Use the ultimate solution....The one that electron microscopes use.....LiPo batteries.
Not only is a totally "off the grid" system immune from all the mains pollution and ground loop issues that plague high end audio systems, but there are no huge fees to get your power supplies certified as safe and legal.....From my point of view this is a major factor.
The way I look at audio systems is focus on the weakest link in the chain and make sure its performing at a very high standard, and then design every other link to exceed this level.
In most systems the loudspeaker is the weakest link, I am delighted with the performance of my own driver / loading / cabinet and now the hunt is on to feed them with the very highest quality signal delivered in the most user friendly manor I can achieve.
I feel you have similar goals and I am sure we can help each other as well as lots of other DIY members and a much wider audience out in the "real world".
One good example is £££ savings: If we can pull together a spec for the right components I believe we can secure a good 100 plus group buy participants to get things going.
Just taking vacuphile's example of the cost of the ESS chip, with 150 orders I can secure a £ well below what most DIY guys pay via DIY IN HK or similar web shops offer.
When you multiply up the savings through the whole system the cost becomes affordable to a much wider audience.
Must dash, taking the kids to see the new Jurassic Park movie...great picture at our local cinema.....Shame about the sound!
Cheers
D.
Hi Stephen,
I totally empathise with you are seeing your core ideas developed into a finished system....when that day comes it will be beautiful!
There are several good options on the DAC front, flagship ESS and AKM DAC's and A to D convertors are all very good indeed.
Also given another 6 months or so R&D I think the R2R board from Soren could be a very good option....It eventually will be able to offer some crossover / Eq functions as well as DAC. It wont have huge number crunching ability but will offer a very low cost way into high end active systems.
On power amplifiers, N Core for bass and First One for mid / top.
On power supplies I have two strong preferences :
(1) Use globally certified high performance switch mode supplies like Hypex.
(2) Use the ultimate solution....The one that electron microscopes use.....LiPo batteries.
Not only is a totally "off the grid" system immune from all the mains pollution and ground loop issues that plague high end audio systems, but there are no huge fees to get your power supplies certified as safe and legal.....From my point of view this is a major factor.
The way I look at audio systems is focus on the weakest link in the chain and make sure its performing at a very high standard, and then design every other link to exceed this level.
In most systems the loudspeaker is the weakest link, I am delighted with the performance of my own driver / loading / cabinet and now the hunt is on to feed them with the very highest quality signal delivered in the most user friendly manor I can achieve.
I feel you have similar goals and I am sure we can help each other as well as lots of other DIY members and a much wider audience out in the "real world".
One good example is £££ savings: If we can pull together a spec for the right components I believe we can secure a good 100 plus group buy participants to get things going.
Just taking vacuphile's example of the cost of the ESS chip, with 150 orders I can secure a £ well below what most DIY guys pay via DIY IN HK or similar web shops offer.
When you multiply up the savings through the whole system the cost becomes affordable to a much wider audience.
Must dash, taking the kids to see the new Jurassic Park movie...great picture at our local cinema.....Shame about the sound!
Cheers
D.
I would be interested in whether any sort of goalposts should be set for any of the final 'products' - how will any of them be assessed for how good they are, how you would explain to someone on the outside that what this activity has produced is "better", say for the money, than something else that had been around for some time, that is conveniently available right now.
What it simply be to say, look, we were able to do this!? Would it be as simple as, this is as good as we can do it, and we reckon it's pretty good!? What would the promotional hook be able to say, with a clear conscience ... ?
What it simply be to say, look, we were able to do this!? Would it be as simple as, this is as good as we can do it, and we reckon it's pretty good!? What would the promotional hook be able to say, with a clear conscience ... ?
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Compared to what Frank and in what context are you asking this question? Like comparing this to a Behringer DSP xo or something like that? I'm not aware of all that many self powered speakers that are doing what Overkill and I want to do. Perhaps you think this is pie in the sky but I don't think so.
Since this is an all-in project, things like what are the projected SPLs that the unit would produce at a certain level of cleanness; peak, especially at the bass end, and some sort of RMS rating - for some standard(?!!) drive signal, music related hopefully, what is the maximum level that the unit can continuously sustain without audible degradation, measured however you wish to do so.
IOW, if I want to put on an pipe organ recital, and symphonic works at realistic levels, will this unit do it for me?
IOW, if I want to put on an pipe organ recital, and symphonic works at realistic levels, will this unit do it for me?
Frankly, I have no profit motive whatsoever. This board is trolled daily by outside interests that are just waiting to take over and copy whatever people are working on that looks remotely exploitable for their own use.
My point is that we should be looking to what the market wants to figure out what is reasonable to build. A screen door fit for submarine use is only useful for a small subset (0.0001) of potential interested parties.
Just like the tablet market, once people started to stop caring when the technology companies would build it and said "screw it" we're building it.
What happened 2 years after a very public build of a working alpha unit? The !phad happened.
A lot of people who put a lot of time into that unit got nearly 100% of nothing for their work. But what did happen, was good for everyone in nearly any field you can think of.
"we can rebuild him...we have the technology...he will be..."
I digress.
I'm just sharing my vision. And I have a background to understand the confluence. I was one of the first people, and still the only person I know in my little part of the world who uses a home-built HTPC to record tv, stream internet video, family compute and listen to music with a nightly backup, from a dedicated server that I also built from parts.
I'm not a visionary - I'm a crazy nerd, who just happened to obsess enough about some of these things to see them come together and do something with them, before people even coined the term "HTPC". Because I'm cheap and couldn't stand the idea of forking over 100 bucks of my own money over for a phone line, internet and premium video programming.
So join in, nobody is saying "yes" or "no". I'll shut up now.
Best,
No. Why?
Because for you, I have no yes answers.
Except for this.
Yes, I still have you on my /ignore list.
I very specifically mention this, because a fellow member up the road has assembled, and tweaked a fairly ambitious, fully active dipole using a DEQX unit to do the splitting, etc. He has adjusted the overall gain so that he can never overcook his speakers, and the downside of that is that recordings with excellent dynamic range, or that are overall low in level hit this bumpstop - the average level then heard from these is about that of a TV set, not exactly that breathtaking!
Because the listener may want to hear emotionally moving reproduction, 🙂 - just like you get in a concert hall, or church. That's how you convince people to climb on board, and put more into getting better sound in the home.
Too much hifi audio is basically TV sound, with a major chunk of walloping bass impact added on - that's not what the real thing is like, and I believe that aiming for the latter is the right path to take ...
No, he was very conscious of getting an extremely flat response, he went to a great deal of trouble to get that calibrated, by others - a chap from DEQX, in fact - designed locally, in Sydney - went to his house, did the procedure. And listening to a frequency sweep, very well done - using twin sealed subwoofers, no sense of any bass anomalies.
The sense of big organ sound requires very clean reproduction, not just ability to handle deep bass notes - and he has that now, but needs to be able to increase the gain so that the levels are closer to the real thing.
The sense of big organ sound requires very clean reproduction, not just ability to handle deep bass notes - and he has that now, but needs to be able to increase the gain so that the levels are closer to the real thing.
He's an audio nut! -- so, is he happy?!!! Noooo, silly question 😛 - there's always the next thing to try, another tweak to implement - what a shame the rest of life has to be put up with !!! ... 😉
Frank,
Any device has an upper limit before the distortion get objectionable. In my case what you have to realize is that the cone surface area is equal to what you would find in most 7" drivers. Where I have an advantage is with much higher linear excursion than a normal speaker, I would say at the extreme once the surround is optimizes 3X the typical linear excursion. What this has done is people seem to just keep turning them up to stupid levels, not distorted but just so loud that it is just not what most people would normally do with this size speaker. As far as playing an organ, go ahead but don't expect a 16hz fundamental wave, that isn't going to happen. I happen to be more than happy with the 35hz bottom end I get from the ported enclosures I have the original prototypes in. You can feel it in your belly, it is hard hitting bass and very clear bass, no mud. I can't speak for Overkill on his speakers, I don't know if he is building a raw frame driver or not. I am sure you would be more than happy with the sound. As far as output goes I think by about 110db I've had enough level in a typical room. I have some other cabinets that will take two of these cone drivers but have never completed them as I just didn't need another 3 to 6db of output. The bass sounds like it comes from a much larger cone, most people blindfolded would say it was a 15" bass driver they were listening to.
The question becomes how much level do you really need to listen to music or a soundtrack? If you wanted lower bass you would have to add a subwoofer, that would only need to handle one octave at most unless you wanted to cut the speaker higher and go for more output. The voicecoils are just cruising along, they are rated for much more power than the speaker needs, a burned voicecoil is not something I want to have to deal with. I considered a way to limit the absolute input voltage but don't know that this wouldn't cause other problems. A limiter in effect.
I also have in my cad files a second design that will look similar, but will have a smaller cone driver for those who want a smaller system and don't listen as loud. I actually built a 3" cone driver using the same motor design, just smaller and put so much power into it I was sure I would fry the coil, I didn't, it was amazing.
On the speaker I have shown many audiophiles will instantly say oh your going to have terrible doppler shift but in reality I don't think you can hear that at all. Perhaps Richard Marsh, he seems to be able to hear a snail slithering!
I also have a 10" version of the speaker but have spent no time optimizing it. That could be used for a subwoofer later if I offer that for home theater use. At some point I will probably offer a complete set of raw frame drivers for the diy crowd and for professional use. That is not on my current list of things to do right now.
I do have about 25 pairs of round raw frame drivers that I can assemble for people who want to build their own speakers, I just don't know what I would charge for them. I was thinking about $300.00 for a pair, they would be hand built, so cosmetically they don't look perfect as the adhesives I am using are so fast it is hard to use manually, but functionally they would be excellent. The speakers have 48 MgOE neo magnets and the newer pieces I am working on have 52MgOE magnets. I don't think most anyone would notice any difference, the efficiency would just be slightly higher.
Any device has an upper limit before the distortion get objectionable. In my case what you have to realize is that the cone surface area is equal to what you would find in most 7" drivers. Where I have an advantage is with much higher linear excursion than a normal speaker, I would say at the extreme once the surround is optimizes 3X the typical linear excursion. What this has done is people seem to just keep turning them up to stupid levels, not distorted but just so loud that it is just not what most people would normally do with this size speaker. As far as playing an organ, go ahead but don't expect a 16hz fundamental wave, that isn't going to happen. I happen to be more than happy with the 35hz bottom end I get from the ported enclosures I have the original prototypes in. You can feel it in your belly, it is hard hitting bass and very clear bass, no mud. I can't speak for Overkill on his speakers, I don't know if he is building a raw frame driver or not. I am sure you would be more than happy with the sound. As far as output goes I think by about 110db I've had enough level in a typical room. I have some other cabinets that will take two of these cone drivers but have never completed them as I just didn't need another 3 to 6db of output. The bass sounds like it comes from a much larger cone, most people blindfolded would say it was a 15" bass driver they were listening to.
The question becomes how much level do you really need to listen to music or a soundtrack? If you wanted lower bass you would have to add a subwoofer, that would only need to handle one octave at most unless you wanted to cut the speaker higher and go for more output. The voicecoils are just cruising along, they are rated for much more power than the speaker needs, a burned voicecoil is not something I want to have to deal with. I considered a way to limit the absolute input voltage but don't know that this wouldn't cause other problems. A limiter in effect.
I also have in my cad files a second design that will look similar, but will have a smaller cone driver for those who want a smaller system and don't listen as loud. I actually built a 3" cone driver using the same motor design, just smaller and put so much power into it I was sure I would fry the coil, I didn't, it was amazing.
On the speaker I have shown many audiophiles will instantly say oh your going to have terrible doppler shift but in reality I don't think you can hear that at all. Perhaps Richard Marsh, he seems to be able to hear a snail slithering!
I also have a 10" version of the speaker but have spent no time optimizing it. That could be used for a subwoofer later if I offer that for home theater use. At some point I will probably offer a complete set of raw frame drivers for the diy crowd and for professional use. That is not on my current list of things to do right now.
I do have about 25 pairs of round raw frame drivers that I can assemble for people who want to build their own speakers, I just don't know what I would charge for them. I was thinking about $300.00 for a pair, they would be hand built, so cosmetically they don't look perfect as the adhesives I am using are so fast it is hard to use manually, but functionally they would be excellent. The speakers have 48 MgOE neo magnets and the newer pieces I am working on have 52MgOE magnets. I don't think most anyone would notice any difference, the efficiency would just be slightly higher.
Steven, that sounds an excellent standard to be working with. 110dB in the room is plenty, provided it's totally clean - what are the sensitivities of the units, roughly? And impedance of the voice coil?
I'm not a bass nut, so Xmax is not relevant - far more important would be the voice coil heating from higher levels of input power, and that then changing audible characteristics.
Edit: on the point of wayward excursions, I would very deliberately prevent pointless cone movements - it amazed me when I investigated small studio monitors, that most of them went into a very obvious merry dance when higher levels were being asked from them! The Behringers I got are extremely well behaved in this respect, and I suspect the overall superior performance they provided is in fact partially due to this.
I'm not a bass nut, so Xmax is not relevant - far more important would be the voice coil heating from higher levels of input power, and that then changing audible characteristics.
Edit: on the point of wayward excursions, I would very deliberately prevent pointless cone movements - it amazed me when I investigated small studio monitors, that most of them went into a very obvious merry dance when higher levels were being asked from them! The Behringers I got are extremely well behaved in this respect, and I suspect the overall superior performance they provided is in fact partially due to this.
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Kindhorn, I sometimes use automotive lightbulbs for protecting voicecoils from heating. Change them like fuses. Mostly when testing for SPLmax. And I can see how much power is delivered, as lightintensity raises with power. Is that too simple for you ? Or not good enough soundvise?
Overkill, I was wondering. Have you seen a difference in performance of the DSP implementation you have, that varies in cycles to process depending on the variability of the response?
Said differently, does a speaker with a more linear response curve impact greatly the performance of the unit's ability to correct for it, within reasonable limits.
If the driver is not optimal, does that create a perfomance issue?
Said differently, does a speaker with a more linear response curve impact greatly the performance of the unit's ability to correct for it, within reasonable limits.
If the driver is not optimal, does that create a perfomance issue?
Frank,
The sensitivity is 86db per watt. That is a function of the extremely long gap, there is no focusing of the magnetic energy, this is dependent on the actual magnetic energy of the magnets, you can not change that in my motor design. It is done specifically to create the most linear motion, it is a linear solenoid designed system I have built both 8 ohm and 4 ohm versions. For a passive crossover it was much cheaper to use the 4 ohm coil as the inductors are half the size. There was no real differences in sensitivity as the change in coil mass of the 8 ohm version made up for the doubling of the wire length, perhaps it was just the exact wire diameter and weight that worked out that way.
As far as uncontrolled cone movement that would typically be some sort of low frequency rumble, perhaps a TT or some subsonic or very low frequencies that those cones don't like. It is more likely that the bass port tuning is not correct and the cone is not loaded correctly. I would think that would be visible if you could see an un-smothed impedance plot. The problem is most published FR and impedance curves are cleaned up so you don't see those perturbations. A waterfall plot would show that also but again most manufacturers smooth these to make them look better.
The sensitivity is 86db per watt. That is a function of the extremely long gap, there is no focusing of the magnetic energy, this is dependent on the actual magnetic energy of the magnets, you can not change that in my motor design. It is done specifically to create the most linear motion, it is a linear solenoid designed system I have built both 8 ohm and 4 ohm versions. For a passive crossover it was much cheaper to use the 4 ohm coil as the inductors are half the size. There was no real differences in sensitivity as the change in coil mass of the 8 ohm version made up for the doubling of the wire length, perhaps it was just the exact wire diameter and weight that worked out that way.
As far as uncontrolled cone movement that would typically be some sort of low frequency rumble, perhaps a TT or some subsonic or very low frequencies that those cones don't like. It is more likely that the bass port tuning is not correct and the cone is not loaded correctly. I would think that would be visible if you could see an un-smothed impedance plot. The problem is most published FR and impedance curves are cleaned up so you don't see those perturbations. A waterfall plot would show that also but again most manufacturers smooth these to make them look better.
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