Last night I managed to use some electrical wire to wire up my NaO. It was based on an early NaO plan before John K’s commercial release (http://www.geocities.com/kreskovs/NaO.html and http://www.musicanddesign.com/).
First of all, the whole system includes my own modifications to the NAD542 that is at an entrance level of high-end sound which I am considering it better than any CD players up to $3,500, a 12B4A preamp based on Brett’s circuit that killed a $4,000 Audio Research preamp, Randy Slone’s flagship Optimos power amps – 135W mono blocks for the main panels and 400W mono blocks for the woofers. All used high quality components. All drivers were straight from the boxes. All capacitors in the passive XO are ICW SA Clarity caps. OPA2134s and MKPs are used in the active XO.
What about the sound!
First, what was it compared to? – my own WWMTMWW hybrid (passive and active) speaker I tweaked for nearly 2 years! It has the Dynaudio Esotar T330D tweeter, the most expensive tweeter by Dynaudio. The midrange drivers are Peerless HDS 5’ that many people rate very highly. The woofers are Peerless HDS 8’ that nobody says it is good for bass. Indeed, after 2 years of fine-tuning I found these woofers so hopeless in bass reproduction that it was impossible to get the WWMTMWW sound right so I decided to dump the project (anyone interested in buying the drivers for lower mid frequency range at cheap prices please drop me an email, these drivers are probably fine from 100Hz to 1k). Nevertheless, after zillions of revisions I have made the passive XO between the T330D and the 5’ HDS to sound so good that from 400Hz up it can compare to the very best.
The NaO U-frame woofer.
In an experiment I connected the MTM part of my WWMTMWW to the NaO U-frame woofer. I expected things had to go wrong because I used the existing active XO with no equalization on the U-frame and I crossed high at 200Hz (the first resonance of the U-frame is just above 150Hz from my memory). Much to my surprise, although the response was not ideal, the single 12’ Peerless XLS in the U-frame outperformed 4 x Peerless HDS 8’ in ported enclosures by far, very far. Now I found the solution for my WWMTMWW – get rid of the WWWW (HDS 8’) and replace it with the NaO U-frame with a proper EQ! The My-MTM-plus-NaO-U-frame, I am sure, beats the B&W 801, the JMLab Grand Utopia, etc., in my personal opinion. So I have got a new future project to do.
Now the NaO.
I turned on the system and was initially disappointed – the sound was just DRY! Not much life in the music. Comparing to the My-MTM-plus-NaO-U-frame, there was no comparison. But I totally forgot that all new drivers straight from boxes sound like that!
Slowly, the sound became better and better. 1.5 hour later, the sound was opened up a lot more. Probably the 18W8545 (paper cone) needed a bit of stretches before they could perform.
The NaO sound was quite different from the My-MTM-plus-NaO-U-frame, as the presentations were different. But after the 1.5 hour burn-in, they were at about the same level of performance despite some rather big differences. In some areas, the My-MTM-plus-NaO-U-frame may be better, but in other areas the NaO may be better.
Let me find some words to describe the NaO sound – accurate, low distortion, micro details, no booms, clean, clean and clean from top to bottom.
I played past midnight and I got too excited and turned it louder and louder until the music woke up my 3-year-old kid on the next floor. He was crying and my wife came out of her bed to complain. So after 2 hours listening I had to turn it off.
This morning I listened to it for another 30 minutes before heading to work. I played the Debussy 12 Etudes (Decca the Original) and to be honest, that was the best solo piano music I had ever heard from a Hi-Fi system. The NaO did it superbly. Note that piano sound is possibly the hardest to reproduce due to its rich harmonics. I have never heard a boxed speaker that can reproduce piano music as real as the NaO. I heard the MBL (certainly not a boxed speaker but that one has a boxed woofer and the price tag is 5 digit) previously at a dealer’s room with 5-to-6-digit-price-tag-per-piece equipment driving it and I was quite impressed by its ability to reproduce piano music. There was no A/B comparison, but my impression was that NaO driven by my equipment is just as good, if not better than that particular MBL (not the highest model as I have never heard that one), when playing the piano music.
Wait until my NaO runs in more and after I correct a number of problems I presently have...
I will hopefully upload a photo tomorrow and provide a bit more details.
I am sure that there are many good speaker projects out there. However, given that NaO is this good, I think it should be given a lot more press. I am happy to share here.
More information will be coming in the coming days.
Regards,
Bill
First of all, the whole system includes my own modifications to the NAD542 that is at an entrance level of high-end sound which I am considering it better than any CD players up to $3,500, a 12B4A preamp based on Brett’s circuit that killed a $4,000 Audio Research preamp, Randy Slone’s flagship Optimos power amps – 135W mono blocks for the main panels and 400W mono blocks for the woofers. All used high quality components. All drivers were straight from the boxes. All capacitors in the passive XO are ICW SA Clarity caps. OPA2134s and MKPs are used in the active XO.
What about the sound!
First, what was it compared to? – my own WWMTMWW hybrid (passive and active) speaker I tweaked for nearly 2 years! It has the Dynaudio Esotar T330D tweeter, the most expensive tweeter by Dynaudio. The midrange drivers are Peerless HDS 5’ that many people rate very highly. The woofers are Peerless HDS 8’ that nobody says it is good for bass. Indeed, after 2 years of fine-tuning I found these woofers so hopeless in bass reproduction that it was impossible to get the WWMTMWW sound right so I decided to dump the project (anyone interested in buying the drivers for lower mid frequency range at cheap prices please drop me an email, these drivers are probably fine from 100Hz to 1k). Nevertheless, after zillions of revisions I have made the passive XO between the T330D and the 5’ HDS to sound so good that from 400Hz up it can compare to the very best.
The NaO U-frame woofer.
In an experiment I connected the MTM part of my WWMTMWW to the NaO U-frame woofer. I expected things had to go wrong because I used the existing active XO with no equalization on the U-frame and I crossed high at 200Hz (the first resonance of the U-frame is just above 150Hz from my memory). Much to my surprise, although the response was not ideal, the single 12’ Peerless XLS in the U-frame outperformed 4 x Peerless HDS 8’ in ported enclosures by far, very far. Now I found the solution for my WWMTMWW – get rid of the WWWW (HDS 8’) and replace it with the NaO U-frame with a proper EQ! The My-MTM-plus-NaO-U-frame, I am sure, beats the B&W 801, the JMLab Grand Utopia, etc., in my personal opinion. So I have got a new future project to do.
Now the NaO.
I turned on the system and was initially disappointed – the sound was just DRY! Not much life in the music. Comparing to the My-MTM-plus-NaO-U-frame, there was no comparison. But I totally forgot that all new drivers straight from boxes sound like that!
Slowly, the sound became better and better. 1.5 hour later, the sound was opened up a lot more. Probably the 18W8545 (paper cone) needed a bit of stretches before they could perform.
The NaO sound was quite different from the My-MTM-plus-NaO-U-frame, as the presentations were different. But after the 1.5 hour burn-in, they were at about the same level of performance despite some rather big differences. In some areas, the My-MTM-plus-NaO-U-frame may be better, but in other areas the NaO may be better.
Let me find some words to describe the NaO sound – accurate, low distortion, micro details, no booms, clean, clean and clean from top to bottom.
I played past midnight and I got too excited and turned it louder and louder until the music woke up my 3-year-old kid on the next floor. He was crying and my wife came out of her bed to complain. So after 2 hours listening I had to turn it off.
This morning I listened to it for another 30 minutes before heading to work. I played the Debussy 12 Etudes (Decca the Original) and to be honest, that was the best solo piano music I had ever heard from a Hi-Fi system. The NaO did it superbly. Note that piano sound is possibly the hardest to reproduce due to its rich harmonics. I have never heard a boxed speaker that can reproduce piano music as real as the NaO. I heard the MBL (certainly not a boxed speaker but that one has a boxed woofer and the price tag is 5 digit) previously at a dealer’s room with 5-to-6-digit-price-tag-per-piece equipment driving it and I was quite impressed by its ability to reproduce piano music. There was no A/B comparison, but my impression was that NaO driven by my equipment is just as good, if not better than that particular MBL (not the highest model as I have never heard that one), when playing the piano music.
Wait until my NaO runs in more and after I correct a number of problems I presently have...
I will hopefully upload a photo tomorrow and provide a bit more details.
I am sure that there are many good speaker projects out there. However, given that NaO is this good, I think it should be given a lot more press. I am happy to share here.
More information will be coming in the coming days.
Regards,
Bill
Thanks Bill. We can read as much as we want about a particular design but there is nothing like a first-hand report of somebody who has actually built it (apart from the designer of course).
I agree, OB has a lot of advantages over boxed speakers, and piano reproduction is one of them! I look forward to your next report!
I agree, OB has a lot of advantages over boxed speakers, and piano reproduction is one of them! I look forward to your next report!
AndrewT said:
Hi,
By definition the open baffle loss causes reduction in SPL capability
for a driver with a given excursion capability, boxes go a lot louder.
The baffle loss increases 6dB per octave as you go lower, so high
levels of very low bass are impractical, requiring huge excursion.
/sreten.
Here is a photo I look last night. My WWMTMWW is put aside.
I have to say I prefer the look of the WWMTMWW but the sound of the NaO.
When I built it, I wasn't sure about its performance especially its SPL on my large room so I did not invest much in the cabinates. I paid a few hundred dollars for a handyman to make them. Now I regrett that.
I will get a furniture making to make a nice pair of cabinates for the NaO as at this stage I think I will keep the NaO for a very long time if not life time.
I have just arrived at work and will give you my second impression of the NaO when I can spare a few moments.
Most of you guys are on the other side of the globe (or I am on the other side) so while you guys are active in the forums I am probably in bed and while I can write in the forums you guys are possibly in bed.
Regards,
Bill
I have to say I prefer the look of the WWMTMWW but the sound of the NaO.
When I built it, I wasn't sure about its performance especially its SPL on my large room so I did not invest much in the cabinates. I paid a few hundred dollars for a handyman to make them. Now I regrett that.
I will get a furniture making to make a nice pair of cabinates for the NaO as at this stage I think I will keep the NaO for a very long time if not life time.
An externally hosted image should be here but it was not working when we last tested it.
I have just arrived at work and will give you my second impression of the NaO when I can spare a few moments.
Most of you guys are on the other side of the globe (or I am on the other side) so while you guys are active in the forums I am probably in bed and while I can write in the forums you guys are possibly in bed.
Regards,
Bill
Hi Bill,
The NaO is probably one of those "evergreen" speakers that will last a lifetime. It uses classic tried and trusted drive elements, and the amount of engineering behind the design is far beyond what most DIYers will ever be capable, or even thought of.
You should definitely build some pretty cabinets for it.
I'm looking forward to hearing more about your NaO after you've had the chance to run in the drive units (typically loosens up the suspension and spider) and found the optimal speaker placement in your room.
....
Anyway, regarding your own DIY attempt at the WWMTMWW- do you have much in the way of measuring equipment?
The "old text-book passive crossover" or "active crossovers purchased over the shelf" will not allow the speaker to reach anywhere near it's potential. Designing a complex multiway speakers such as a WWMTMWW will invariably need measurement tools. And after being armed with all these tools, we need to do further research and build up experience level with designing crossovers.
A lot of DIYers dive into the deep end, and don't bother too much with measurements ("Trust our ears" we cry!) but if we can't pinpoint the exact problem, how are we going to fix it? We can try tweak after tweak after tweak, and sometimes we go forward other times it takes us a step backwards. But the best we're doing is shooting in the dark.
The NaO is probably one of those "evergreen" speakers that will last a lifetime. It uses classic tried and trusted drive elements, and the amount of engineering behind the design is far beyond what most DIYers will ever be capable, or even thought of.
You should definitely build some pretty cabinets for it.
I'm looking forward to hearing more about your NaO after you've had the chance to run in the drive units (typically loosens up the suspension and spider) and found the optimal speaker placement in your room.
....
Anyway, regarding your own DIY attempt at the WWMTMWW- do you have much in the way of measuring equipment?
The "old text-book passive crossover" or "active crossovers purchased over the shelf" will not allow the speaker to reach anywhere near it's potential. Designing a complex multiway speakers such as a WWMTMWW will invariably need measurement tools. And after being armed with all these tools, we need to do further research and build up experience level with designing crossovers.
A lot of DIYers dive into the deep end, and don't bother too much with measurements ("Trust our ears" we cry!) but if we can't pinpoint the exact problem, how are we going to fix it? We can try tweak after tweak after tweak, and sometimes we go forward other times it takes us a step backwards. But the best we're doing is shooting in the dark.
You guys are spot on! everything you said is right!
Now, the second impression.
I have now played it 2.5 hours more and the sound is opened up more and more. The Seas Excel Millennium tweeter and the ScanSpeak’s 18W5845 mid woofers have now a total run-in time of 5 hours. I guess they should be about 85% run-in. The rest may take another a few weeks.
Remember I said the NaO was very different from the MyMTM-plus-NaO-U-Frame? I should start calling it myMTM now to make the word shorter. Amusingly, after the run-in, the gap between the two has narrowed considerably.
This is because myMTM, also open back (I won’t call it a dipole though), was no lesser than a reference type of speaker from 300-400Hz up and can compare to most of anything else out there. It was run-in and tweaked for 2 years and is close to perfection. It throws out such an accurate, very deep, very wide and tall 3-D image and the sound is very smooth and musical, thanks for the great Esotar T330D and the HDS 5’ doing a good job.
Previously, myMTM was better than the NaO in the openness of the sound / the disappearing act (it may still be the case until the NaO is fully run-in), but the NaO is closing up, as for now, which speaker is better depending on what types of music I play:
NaO (after 5 hours run-in) vs myMTM
Noah Jones’ debut album – hard to say which is better, only small differences.
John Martin Solid Air - hard to say which is better.
Eden of North – Sum of Us – myMTM killed the NaO.
Jennifer Warm – myMTM betters the NaO by a small margin?
Johnny Cash - myMTM betters the NaO by a small margin.
Mozart Violin Concerto – myMTM betters the NaO by a small margin.
Miles Davis – A Kind of Blue – myMTM betters the NaO by a small margin.
Church Organ and Choral – NaO killed myMTM.
Solo piano music – NaO killed myMTM.
Britten’s Stage show – NaO killed myMTM.
William Tell by Telarc – NaO killed myMTM.
Where myMTM is better -
The NaO is limited in SPL of the Excel tweeter. myMTM is significantly better when high SPL is required. It has 94 dB sensitivity and in my 9 metre wide x 13 metre long x high ceiling relatively large and dead room, when live music level is required with high impacts, the myMTM can deliver the power in an awesome, spectacular way without letting you feel fatigue whatsoever. The XO between the T330D and the HDS was nearly perfected. Female voices are super smooth. I can say I prefer the T330D tweeter (from my memory it has the power handing capability of around 200-300W RMS continues and peak over 1000W) over the Seas Excel Millennium tweeter T25CF-002. It seems the sound of T330D is more natural. That is why when it comes to Mozart’s Violin Concerto (Decca Legend) when playing loud David Oistrakh’s violin sounds better from the T330D than from the T25CF-002. I played violin when I was a boy and am familiar with life classical music instrument sound.
In contrast, there is a small hint of grain or edge from 1k up somewhere in the NaO which affects the violin sound as well as human voice reproduction. Does this make me believe the T330D is better than the T25CF-002? Possibly. That is the area where myMTM wins over the NaO by a small margin in Eden of North, Jennifer Warm and Johnny Cash. Another problem with the NaO is that I found somewhere from 80Hz to 150Hz the sound is lacking which gives myMTM a ticket to win. The result is that the myMTM has more impacts for certain music with a fuller sound while the NaO sounds a bit thin. That is why for Eden of North and A Kind of Blue myMTM won. But I have to confess this is not John K’s fault – I was one of the earliest guys who got the free NaO plan and I only had the NaO EQ and the Peerless XLS 12’ EQ schematics hand-drawn by John K. John K at the time recommended using the standard LR4 while I used the 3rd order Bessel for the NaO and probably that ruined the frequency response between 80Hz to 150Hz. I have to say my NaO was not implemented exactly according to John’s plan because I had not had enough time. I simply quickly put them together to test the sound. I hope I have not done the active XO incorrectly. Note that my NaO is not the later, more tested and matured NaO II in John’s commercial release.
Where the NaO wins:
Where details are required the NaO blows the myMTM away. The T330D probably has the details of the T25CF-002 but the 18W5845 kills the HDS 5’ instantly. There was no contest. The HDS 5’ gives a more rounded (i.e. coloured) sound that is quite natural and musical but do not have the details of the 18W5845. If you ask me which one I prefer I say I prefer the 18W5845 without a doubt. The clean sound of dipole also plays a role here. This gives a lot more realism to the music.
In the dynamic department again the NaO killed the myMTM. Is this because of the 18W5848? I don’t know. The myMTM is already a very dynamic speaker but the NaO is still more dynamic.
Transient is excellent with the NaO. So it won on solo piano music, William Tell by Telarc, Britten’s stage show and many other CDs I have.
The 3-D effect is getting better along run-in. Voices sound real (dispite the above mentioned slight problem). Drums were hit fast with might. There are no booms-booms-booms. No bass hung-over.
After 5 hours run-in, if you ask me which speaker is better, I’d say the NaO. I am sure once I corrected a number of problems with my implementation of the NaO, it may sound faultless.
In the coming weekend, I will do some changes to my NaO. When I wired up the passive XO for all the switches I simply chose the mean value and had no time to study what they do. I will experiment with various values to get the best sound. John K said the stuffing material for the U-frame must be either fibreglass or wool. I didn’t know where I could get wool so I temporarily use Polyfill that John had already said useless. There are others, too.
More to come…
Regards,
Bill
Now, the second impression.
I have now played it 2.5 hours more and the sound is opened up more and more. The Seas Excel Millennium tweeter and the ScanSpeak’s 18W5845 mid woofers have now a total run-in time of 5 hours. I guess they should be about 85% run-in. The rest may take another a few weeks.
Remember I said the NaO was very different from the MyMTM-plus-NaO-U-Frame? I should start calling it myMTM now to make the word shorter. Amusingly, after the run-in, the gap between the two has narrowed considerably.
This is because myMTM, also open back (I won’t call it a dipole though), was no lesser than a reference type of speaker from 300-400Hz up and can compare to most of anything else out there. It was run-in and tweaked for 2 years and is close to perfection. It throws out such an accurate, very deep, very wide and tall 3-D image and the sound is very smooth and musical, thanks for the great Esotar T330D and the HDS 5’ doing a good job.
Previously, myMTM was better than the NaO in the openness of the sound / the disappearing act (it may still be the case until the NaO is fully run-in), but the NaO is closing up, as for now, which speaker is better depending on what types of music I play:
NaO (after 5 hours run-in) vs myMTM
Noah Jones’ debut album – hard to say which is better, only small differences.
John Martin Solid Air - hard to say which is better.
Eden of North – Sum of Us – myMTM killed the NaO.
Jennifer Warm – myMTM betters the NaO by a small margin?
Johnny Cash - myMTM betters the NaO by a small margin.
Mozart Violin Concerto – myMTM betters the NaO by a small margin.
Miles Davis – A Kind of Blue – myMTM betters the NaO by a small margin.
Church Organ and Choral – NaO killed myMTM.
Solo piano music – NaO killed myMTM.
Britten’s Stage show – NaO killed myMTM.
William Tell by Telarc – NaO killed myMTM.
Where myMTM is better -
The NaO is limited in SPL of the Excel tweeter. myMTM is significantly better when high SPL is required. It has 94 dB sensitivity and in my 9 metre wide x 13 metre long x high ceiling relatively large and dead room, when live music level is required with high impacts, the myMTM can deliver the power in an awesome, spectacular way without letting you feel fatigue whatsoever. The XO between the T330D and the HDS was nearly perfected. Female voices are super smooth. I can say I prefer the T330D tweeter (from my memory it has the power handing capability of around 200-300W RMS continues and peak over 1000W) over the Seas Excel Millennium tweeter T25CF-002. It seems the sound of T330D is more natural. That is why when it comes to Mozart’s Violin Concerto (Decca Legend) when playing loud David Oistrakh’s violin sounds better from the T330D than from the T25CF-002. I played violin when I was a boy and am familiar with life classical music instrument sound.
In contrast, there is a small hint of grain or edge from 1k up somewhere in the NaO which affects the violin sound as well as human voice reproduction. Does this make me believe the T330D is better than the T25CF-002? Possibly. That is the area where myMTM wins over the NaO by a small margin in Eden of North, Jennifer Warm and Johnny Cash. Another problem with the NaO is that I found somewhere from 80Hz to 150Hz the sound is lacking which gives myMTM a ticket to win. The result is that the myMTM has more impacts for certain music with a fuller sound while the NaO sounds a bit thin. That is why for Eden of North and A Kind of Blue myMTM won. But I have to confess this is not John K’s fault – I was one of the earliest guys who got the free NaO plan and I only had the NaO EQ and the Peerless XLS 12’ EQ schematics hand-drawn by John K. John K at the time recommended using the standard LR4 while I used the 3rd order Bessel for the NaO and probably that ruined the frequency response between 80Hz to 150Hz. I have to say my NaO was not implemented exactly according to John’s plan because I had not had enough time. I simply quickly put them together to test the sound. I hope I have not done the active XO incorrectly. Note that my NaO is not the later, more tested and matured NaO II in John’s commercial release.
Where the NaO wins:
Where details are required the NaO blows the myMTM away. The T330D probably has the details of the T25CF-002 but the 18W5845 kills the HDS 5’ instantly. There was no contest. The HDS 5’ gives a more rounded (i.e. coloured) sound that is quite natural and musical but do not have the details of the 18W5845. If you ask me which one I prefer I say I prefer the 18W5845 without a doubt. The clean sound of dipole also plays a role here. This gives a lot more realism to the music.
In the dynamic department again the NaO killed the myMTM. Is this because of the 18W5848? I don’t know. The myMTM is already a very dynamic speaker but the NaO is still more dynamic.
Transient is excellent with the NaO. So it won on solo piano music, William Tell by Telarc, Britten’s stage show and many other CDs I have.
The 3-D effect is getting better along run-in. Voices sound real (dispite the above mentioned slight problem). Drums were hit fast with might. There are no booms-booms-booms. No bass hung-over.
After 5 hours run-in, if you ask me which speaker is better, I’d say the NaO. I am sure once I corrected a number of problems with my implementation of the NaO, it may sound faultless.
In the coming weekend, I will do some changes to my NaO. When I wired up the passive XO for all the switches I simply chose the mean value and had no time to study what they do. I will experiment with various values to get the best sound. John K said the stuffing material for the U-frame must be either fibreglass or wool. I didn’t know where I could get wool so I temporarily use Polyfill that John had already said useless. There are others, too.
More to come…
Regards,
Bill
Andrew T - "Does the bass go deep?"
Yes the NaO bass goes VERY DEEP. Funny though, one would expect that the NaO U-frame would be bottomed first. I have not found that to be a problem yet or perhaps I was ignorant. I played the famous Cantata Domino CD by Proprius and that church organ did not bottom the NaO U-frame. Neither did the Particia Barber's Cafe Blue. I played it quite loud in my fairly large room.
Seriously, I have a new problem. When the NaO goes deep down a lot of vibration noises came from everywhere in my room - the glasses in the wine bar, windows, and who knows where they come from. The noise are loud and very annoying. When I have time I have to debug the problem and remove those items. I can't remove the windows though.
Andrew T - "Are there SPL limitations that are worse than boxed bass drivers?"
After I got the plan from John K, I had some email exchanges with him. It was a long time ago. I remember John said the SPL was limited to the Excel Tweeter.
As said, the U-frame with a 12' XLS may be fine. I did find limitation on the main panel. With my 9 x 13 metre fairly large and dead room, I wish the NaO could play a bit louder. It is generally loud enough for 80% of my music, but just, or I am pushing it to its limit. If I want to play very loud, the NaO main panel would struggle.
I have to mention one thing - I often play music very loud to live level with myMTM. I stay upstairs most of the time and I just let myMTM downstairs to play loud. That is very loud. If you are not as crazy as me or if you have a smaller room then the NaO may be loud enough for you.
Why Dynaudio stopped making the Esotar T330D? I could image if John K started his NaO design with the Esotar... the NaO would be the ultimate speaker!!!
Yes the NaO bass goes VERY DEEP. Funny though, one would expect that the NaO U-frame would be bottomed first. I have not found that to be a problem yet or perhaps I was ignorant. I played the famous Cantata Domino CD by Proprius and that church organ did not bottom the NaO U-frame. Neither did the Particia Barber's Cafe Blue. I played it quite loud in my fairly large room.
Seriously, I have a new problem. When the NaO goes deep down a lot of vibration noises came from everywhere in my room - the glasses in the wine bar, windows, and who knows where they come from. The noise are loud and very annoying. When I have time I have to debug the problem and remove those items. I can't remove the windows though.
Andrew T - "Are there SPL limitations that are worse than boxed bass drivers?"
After I got the plan from John K, I had some email exchanges with him. It was a long time ago. I remember John said the SPL was limited to the Excel Tweeter.
As said, the U-frame with a 12' XLS may be fine. I did find limitation on the main panel. With my 9 x 13 metre fairly large and dead room, I wish the NaO could play a bit louder. It is generally loud enough for 80% of my music, but just, or I am pushing it to its limit. If I want to play very loud, the NaO main panel would struggle.
I have to mention one thing - I often play music very loud to live level with myMTM. I stay upstairs most of the time and I just let myMTM downstairs to play loud. That is very loud. If you are not as crazy as me or if you have a smaller room then the NaO may be loud enough for you.
Why Dynaudio stopped making the Esotar T330D? I could image if John K started his NaO design with the Esotar... the NaO would be the ultimate speaker!!!
tktran303,
You are absolutely right. For my WWMTMWW I did the XO in the hardest, most stupid way without measuring equipment. I love to have the measuring equipment but I don't know what microphone to get and all the microphones mentioned in the forum seem to be only available overseas but not in OZ. I really want to have it now.
However, from very early on I had abandoned the text book XO formulaes. I entered the FRD and ZMA files manually according to the manufacturers' data sheets into Speaker Workshop and other software provided in the Frequency Response Consortium website. I have to say the data sheets seem to be quite accurate.
All the XOs I tried were first modelled in Speaker Workshop, and I have tried textbook like 1st order, 2nd order, 3rd order and 4th order and more.
I have tried series XO as well and found for the T330D and the HDS 5' the Real Accoustic's series XO sounds very good - of course I don't use their recommended values but SW's. But it was not perfect and there was one problem I could not rectify - that is with series XOs - not easy to alter the FR near the XO. So it was abandoned.
I have tried various XO points from 2k to 9k in parallel networks. Eventually, I got this:
The small dip between 2k to 5k is deliberate as it sounds better (still a lot smaller than the BBC dip). I prefer the HF not too dominant so don't mind the 1dB lower towards HF. Baffle step is at 410Hz and that can be compensated by boosting the woofer by up to 3 dB. Diffraction was not considered.
Note that from 200Hz to 10kHz the variation from SW is only +-1.5dB.
If you see the graph carefully, the XO point is just about 3.1kHz. At about 1.65k it was 24dB down. At about 6.2k it was 24dB down (the HDS should be seen as 6dB higher as the 2 HDS are connected in parallel). At XO point it is close to 6dB down. This is a LR4 network.
I achieved this by this very simple schematic, the result of two years efforts:
Before the final schematic was fixed, I tuned the resistors by increasing / decreasing 0.05 ohms and wind / unwind inductors by 1/3 turn at a time to get the optimal sound. It was extraordinary tedius and I swear I won't do it again in the same way.
For the active XO, I used 3rd order Bessel. I used only 2 opamps for the HF and 2 opamps in the LF. This includes attenuation as well as input buffer.
You are absolutely right. For my WWMTMWW I did the XO in the hardest, most stupid way without measuring equipment. I love to have the measuring equipment but I don't know what microphone to get and all the microphones mentioned in the forum seem to be only available overseas but not in OZ. I really want to have it now.
However, from very early on I had abandoned the text book XO formulaes. I entered the FRD and ZMA files manually according to the manufacturers' data sheets into Speaker Workshop and other software provided in the Frequency Response Consortium website. I have to say the data sheets seem to be quite accurate.
All the XOs I tried were first modelled in Speaker Workshop, and I have tried textbook like 1st order, 2nd order, 3rd order and 4th order and more.
I have tried series XO as well and found for the T330D and the HDS 5' the Real Accoustic's series XO sounds very good - of course I don't use their recommended values but SW's. But it was not perfect and there was one problem I could not rectify - that is with series XOs - not easy to alter the FR near the XO. So it was abandoned.
I have tried various XO points from 2k to 9k in parallel networks. Eventually, I got this:
An externally hosted image should be here but it was not working when we last tested it.
The small dip between 2k to 5k is deliberate as it sounds better (still a lot smaller than the BBC dip). I prefer the HF not too dominant so don't mind the 1dB lower towards HF. Baffle step is at 410Hz and that can be compensated by boosting the woofer by up to 3 dB. Diffraction was not considered.
Note that from 200Hz to 10kHz the variation from SW is only +-1.5dB.
If you see the graph carefully, the XO point is just about 3.1kHz. At about 1.65k it was 24dB down. At about 6.2k it was 24dB down (the HDS should be seen as 6dB higher as the 2 HDS are connected in parallel). At XO point it is close to 6dB down. This is a LR4 network.
I achieved this by this very simple schematic, the result of two years efforts:
An externally hosted image should be here but it was not working when we last tested it.
Before the final schematic was fixed, I tuned the resistors by increasing / decreasing 0.05 ohms and wind / unwind inductors by 1/3 turn at a time to get the optimal sound. It was extraordinary tedius and I swear I won't do it again in the same way.
For the active XO, I used 3rd order Bessel. I used only 2 opamps for the HF and 2 opamps in the LF. This includes attenuation as well as input buffer.
tktran303,
For the WWMTMWW, driver offset was taken into account. From SW text book theories were proven correct - LR4 network is less sensitive to driver offset. With an offset from 0cm to 3.5cm, the on-axis FR is still very acceptable, not an issue here.
Note that the MTM is also OPEN BACK! it has no back panel. Midium to Heavy stuffing was used so the sound coming from the back is a multitude of dBs down therefore it is not a dipole or U-frame. However, box-sound is significantly reduced. Should I call it a tranmission line since it has got this depth? I don't know.
It is perhaps due to the less box-sound, the simple passive XO network with small number of components while achieving almost textbook like LR4 alignment, and only 2 opamps in the signal path for both the HF and LF in the active filter, that make this speaker sound very good.
I didn't design or build it. A friend of mine did it and took it to the CES2001-CES2003 shows selling it for US$15,000. I bought it from him for AUD$7,500 before I started my DIY hobby. That was the last piece of HiFi equipment I bought. At the time, it had a single cap XOed at 9k and a decret FET 2nd order butterworth active XO at 500Hz. The transient was extraordinary good but I could not stand hearing the stress of the T330D near 1k and all the cone break-ups of the HDS. I put in some high quality sound insulation / absorbing materials (used for motor vehicle sound damping) through out the entire internal panels and that made a big improvement. I crossed the 5' HDS to 8' HDS at 200Hz with 3rd order Bessel.
My work has transformed it into a much better speaker. If I took out the WWWW and used the NaO U-frame, I am sure it beats the B&W 801 and the AUD$130,000 JMLab Grand Utopia (I listened to that speaker for 5 times in some very expensive set up!)
For the WWMTMWW, driver offset was taken into account. From SW text book theories were proven correct - LR4 network is less sensitive to driver offset. With an offset from 0cm to 3.5cm, the on-axis FR is still very acceptable, not an issue here.
Note that the MTM is also OPEN BACK! it has no back panel. Midium to Heavy stuffing was used so the sound coming from the back is a multitude of dBs down therefore it is not a dipole or U-frame. However, box-sound is significantly reduced. Should I call it a tranmission line since it has got this depth? I don't know.
It is perhaps due to the less box-sound, the simple passive XO network with small number of components while achieving almost textbook like LR4 alignment, and only 2 opamps in the signal path for both the HF and LF in the active filter, that make this speaker sound very good.
I didn't design or build it. A friend of mine did it and took it to the CES2001-CES2003 shows selling it for US$15,000. I bought it from him for AUD$7,500 before I started my DIY hobby. That was the last piece of HiFi equipment I bought. At the time, it had a single cap XOed at 9k and a decret FET 2nd order butterworth active XO at 500Hz. The transient was extraordinary good but I could not stand hearing the stress of the T330D near 1k and all the cone break-ups of the HDS. I put in some high quality sound insulation / absorbing materials (used for motor vehicle sound damping) through out the entire internal panels and that made a big improvement. I crossed the 5' HDS to 8' HDS at 200Hz with 3rd order Bessel.
My work has transformed it into a much better speaker. If I took out the WWWW and used the NaO U-frame, I am sure it beats the B&W 801 and the AUD$130,000 JMLab Grand Utopia (I listened to that speaker for 5 times in some very expensive set up!)
Now the run-in hours of the NaO has reached 10. The sound is now further opened up. The 3D sound and the disappearing act matched that of myMTM that has run-in for 2 years.
The NaO betters the myMTM in every way except the following:
1. SPL.
2. In the high frequency range above 1k the myMTM is still a bit smoother.
3. The upper bass / lower mid range in the NaO has something missing, making the sound a bit thin hence less musical.
In all other areas, the NaO blows the myMTM away, such as details, clarity, textual, realism, transient, dynamic.
Let me say if the NaO does not have the above 3 issues, it will be pretty much a perfect speaker.
I am now convinced that a very well designed dipole is in a different class.
I sent an email to John K asking some questions about his new active circuit and I got his reply yesterday. John told me that in his NaO II the active and passive circuits were completely changed and there were significant improvements made. I am yet to test that but it seems what John said makes sense. He mentioned that there was a resonance at 3.2k from the midwoofers that was not addressed previously in the NaO that is now addressed in the NaO II. No wonder I found human voices and violins sound slightly better on the myMTM than the NaO! And I was blaming the Excel tweeter! He also mentioned that the new active circuit has better integration between the U-frame and the panel and I certainly hope it has addressed the issue No 3.
That was a bad and good news for me. The bad news is that none of the components in the previous filter networks, especially the passive, can be reused. I lost a few hundred dollars on those big inductors and capacitors! The good news is of course if the new NaO has fixed those problems then I will have eventually got my ultimate speaker (except SPL so I will still persume myMTM-plus-NaO-U-frame in the future, and I hope you guys can help with that new project!).
So I decided to abandon my plan to tweak it this weekend. Yesterday after I got John's email I immediately sent a postal cheque to John K to order the new NaO update (not the full NaO II plan).
I will resurrect this thread and report to you how the new NaO sounds once I build the new NaO filters.
Best regards and Have fun DIY.
Bill
The NaO betters the myMTM in every way except the following:
1. SPL.
2. In the high frequency range above 1k the myMTM is still a bit smoother.
3. The upper bass / lower mid range in the NaO has something missing, making the sound a bit thin hence less musical.
In all other areas, the NaO blows the myMTM away, such as details, clarity, textual, realism, transient, dynamic.
Let me say if the NaO does not have the above 3 issues, it will be pretty much a perfect speaker.
I am now convinced that a very well designed dipole is in a different class.
I sent an email to John K asking some questions about his new active circuit and I got his reply yesterday. John told me that in his NaO II the active and passive circuits were completely changed and there were significant improvements made. I am yet to test that but it seems what John said makes sense. He mentioned that there was a resonance at 3.2k from the midwoofers that was not addressed previously in the NaO that is now addressed in the NaO II. No wonder I found human voices and violins sound slightly better on the myMTM than the NaO! And I was blaming the Excel tweeter! He also mentioned that the new active circuit has better integration between the U-frame and the panel and I certainly hope it has addressed the issue No 3.
That was a bad and good news for me. The bad news is that none of the components in the previous filter networks, especially the passive, can be reused. I lost a few hundred dollars on those big inductors and capacitors! The good news is of course if the new NaO has fixed those problems then I will have eventually got my ultimate speaker (except SPL so I will still persume myMTM-plus-NaO-U-frame in the future, and I hope you guys can help with that new project!).
So I decided to abandon my plan to tweak it this weekend. Yesterday after I got John's email I immediately sent a postal cheque to John K to order the new NaO update (not the full NaO II plan).
I will resurrect this thread and report to you how the new NaO sounds once I build the new NaO filters.
Best regards and Have fun DIY.
Bill
(JPK) I want to thank Bill for is unbiased comments about the NaO. I would also like to state that the version of the NaO he did build was basically the very first generation of the original NaO designed in October of 2003. Over the last two and 1/2, going on 3, years the NaO evolved into the NaO P and the NaO II, and currently only the NaO II, with considerable refinement in all aspects of the design. The original NaO was intended as a quick and simple design requiring an extremely simple active circuit which could be build on a bread board. Since then the speaker has evolved with refinement to the passive midrange to tweeter crossover and with more sophisticated active circuitry. I have tried to make the updates made over the last 2 1/2 years available to all those who have actually built a NaO system, however, it has been difficult to keep track of all those who requested and received the free plans (like Bill) for the original design (now obsolete).
Bill mentioned 3 problems area with the Original NaO. I would like to address each since I believe the updates which he has just received are directed at those areas.
1) Max SPL: The SPL limitations of the current NaO II are primarily associated with the excursion limits of the midrange drivers just above the low frequency cut off. In the design of the NaO II the woofer was switched from a single 12” to either a single or dual 10" configuration. This allowed me to push the mid/woofer crossover some what higher in frequency. This gives the NaO II better than a 4.5dB increase in max SPL over the original NaO in the mid/woofer crossover frequency range. Additionally, the latest version of the passive crossover and active circuits improves the system sensitivity in the upper midrange by as much a 6dB yielding improved dynamic range with a given amplifier power. Since the crossover frequency for the original NaO with 12" woofer must remain somewhat lower than that of the NaO II not all of these benefits will be apparent when the updates are applied to the original NaO.
2) As Bill already pointed out the new version of the passive crossover for the NaO II addresses a resonance associated with the SS 8545 driver above the crossover frequency that was not addressed in the original design. The crossover between mids and tweeter has also been refined. I will be interested to read Bill comments regarding to the smoothness above 1K once he completes his update.
3) The last comment concerned the transition between woofer and midrange and perhaps some thinness in this area. Here I would like to point out that in the original, free version of the NaO design the crossover between mids and woofer was left to the builder with some suggestions presented on my web sight. With the development of the active circuits used for the later versions of the NaO and the evolution into the NaO II the woofer/midrange crossover was designed specifically for the integration of the mids and woofer system. Additionally, the active circuits allow adjustment of response below 200 Hz in addition to a separate woofer level.
Again, I want to thank Bill for is efforts in building the system and also in posting his comments. I am looking forward to reading his additional comments once he completes the updates to the system.
Bill mentioned 3 problems area with the Original NaO. I would like to address each since I believe the updates which he has just received are directed at those areas.
1) Max SPL: The SPL limitations of the current NaO II are primarily associated with the excursion limits of the midrange drivers just above the low frequency cut off. In the design of the NaO II the woofer was switched from a single 12” to either a single or dual 10" configuration. This allowed me to push the mid/woofer crossover some what higher in frequency. This gives the NaO II better than a 4.5dB increase in max SPL over the original NaO in the mid/woofer crossover frequency range. Additionally, the latest version of the passive crossover and active circuits improves the system sensitivity in the upper midrange by as much a 6dB yielding improved dynamic range with a given amplifier power. Since the crossover frequency for the original NaO with 12" woofer must remain somewhat lower than that of the NaO II not all of these benefits will be apparent when the updates are applied to the original NaO.
2) As Bill already pointed out the new version of the passive crossover for the NaO II addresses a resonance associated with the SS 8545 driver above the crossover frequency that was not addressed in the original design. The crossover between mids and tweeter has also been refined. I will be interested to read Bill comments regarding to the smoothness above 1K once he completes his update.
3) The last comment concerned the transition between woofer and midrange and perhaps some thinness in this area. Here I would like to point out that in the original, free version of the NaO design the crossover between mids and woofer was left to the builder with some suggestions presented on my web sight. With the development of the active circuits used for the later versions of the NaO and the evolution into the NaO II the woofer/midrange crossover was designed specifically for the integration of the mids and woofer system. Additionally, the active circuits allow adjustment of response below 200 Hz in addition to a separate woofer level.
Again, I want to thank Bill for is efforts in building the system and also in posting his comments. I am looking forward to reading his additional comments once he completes the updates to the system.
NaO Mini
Hi Everyone,
I'm a novice DIYer and just starting to gather and improve my equipment.
This is the first thread I've seen regarding the NaO's, so I was encouraged to make my first post to this forum. I just finished building some NaO Mini's. John K. redesigned the passive crossovers for use with Vifa XG18's and Seas 27TDFC's and redesigned and built the active circuits for me to use the Mini's with my existing sealed subwoofers.
I have some sub amp problems, so I can't give much of a review at this point, but what I have heard (before amp problems and break in) was exceptional, in my limited listening experience. I can't wait to get the amp problem addressed so I can do some serious listening.
John K. is a pleasure to work with and gives unequaled support. The design of the Mini's make great sound possible for even the beginner, for a modest price, IMO.
Attached are a couple photo's of the Modified NaO Mini on one of the subs, and the MTM's standing alone. I will try to follow up with more info if anyone is interested.
Cheers,
Dan
Hi Everyone,
I'm a novice DIYer and just starting to gather and improve my equipment.
This is the first thread I've seen regarding the NaO's, so I was encouraged to make my first post to this forum. I just finished building some NaO Mini's. John K. redesigned the passive crossovers for use with Vifa XG18's and Seas 27TDFC's and redesigned and built the active circuits for me to use the Mini's with my existing sealed subwoofers.
I have some sub amp problems, so I can't give much of a review at this point, but what I have heard (before amp problems and break in) was exceptional, in my limited listening experience. I can't wait to get the amp problem addressed so I can do some serious listening.
John K. is a pleasure to work with and gives unequaled support. The design of the Mini's make great sound possible for even the beginner, for a modest price, IMO.
Attached are a couple photo's of the Modified NaO Mini on one of the subs, and the MTM's standing alone. I will try to follow up with more info if anyone is interested.
Cheers,
Dan
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Bill,
I noticed you use(d) 200Hz 3rd order Bessel between mids and woofers in your WWMTMWW construction. What model HDS are those woofers, how large cabinets did you use and what tuning frequency?
And what seems to be the primary or few primary problems of that bass solution?
At least your large room doesn't sound like a big problem and it could use some good old fashion grunt.
Jussi
I noticed you use(d) 200Hz 3rd order Bessel between mids and woofers in your WWMTMWW construction. What model HDS are those woofers, how large cabinets did you use and what tuning frequency?
And what seems to be the primary or few primary problems of that bass solution?
At least your large room doesn't sound like a big problem and it could use some good old fashion grunt.
Jussi
Hi,
I just got my customized NaO Mini's partially up and running yesterday (Vifa XG18's instead of the Peerless, and a customized baffle). One of the sub pair is still out, but I hope to remedy that by Monday or Tuesday.
I don't have the equipment yet to take measurements, but will be doing some auditioning over the weekend (with only one sub running)and I will try to give you an idea of what my ears tell me.
My impression so far, without focusing on that aspect, is that they are very good off axis, both horizontally and vertically.
Cheers,
Dan
I just got my customized NaO Mini's partially up and running yesterday (Vifa XG18's instead of the Peerless, and a customized baffle). One of the sub pair is still out, but I hope to remedy that by Monday or Tuesday.
I don't have the equipment yet to take measurements, but will be doing some auditioning over the weekend (with only one sub running)and I will try to give you an idea of what my ears tell me.
My impression so far, without focusing on that aspect, is that they are very good off axis, both horizontally and vertically.
Cheers,
Dan
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