Ziggy said:
In fact 1mm balsa is not heavier than quality printing paper. Here is the CSD of the 2x0.8mm magnetostat:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=80797&perpage=25&highlight=&pagenumber=3
Behaves very much like a DML in the highs. I didn´t try this concept with cardboard, so i can´t say whether transparency of the balsa is worse here, too.
Aluminium decays much faster. I've tried adding the mass to monomorph brass plate and piezo plate but got contraction result to what I have wrote 
Mass on piezo plate == higher modal density, higher first mode
Mass on brass plate == 6db louder
Today I phoned an old mechanical science professor who developed models for Stradivarius type violins and built prototype in 1985. There are two ways of lowering internal damping in wood: cold stretching and chemical modification.
Mass on piezo plate == higher modal density, higher first mode
Mass on brass plate == 6db louder
Today I phoned an old mechanical science professor who developed models for Stradivarius type violins and built prototype in 1985. There are two ways of lowering internal damping in wood: cold stretching and chemical modification.
Attachments
Going off subject here a bit : in my last post, I accused my receiver of possible lack of highs.
I did a blind test with the help of a friend last night and we both eventually agreed that the receiver was not lacking in highs at all.
In fact, it had better highs than a homemade 300B valve amplifier with silver wired transformers !!
So, I take it all back (again!!!
: ).......be careful when you evaluate or ''think'' that you are evaluating sources. It can be very tricky
Of interest also was the Pioneer's sensitivity to interconnects - vastly preferring solid core copper wire to stranded. That was not my imagination!.........fantastic highs from the panels.
This hobby is really ******* me off!!!
I did a blind test with the help of a friend last night and we both eventually agreed that the receiver was not lacking in highs at all.
In fact, it had better highs than a homemade 300B valve amplifier with silver wired transformers !!
So, I take it all back (again!!!
: ).......be careful when you evaluate or ''think'' that you are evaluating sources. It can be very tricky Of interest also was the Pioneer's sensitivity to interconnects - vastly preferring solid core copper wire to stranded. That was not my imagination!.........fantastic highs from the panels.
This hobby is really ******* me off!!!
http://www.diyaudio.com/forums/attachment.php?s=&postid=1831258&action=thumb&stamp=1242679394
Maybe new name: Distorted mode loudspeaker
Maybe new name: Distorted mode loudspeaker
Mor den Siur, your attached image is so small it's useless(as is your posting).............CHOLERA!!!!!!(Polish swear word)
If it attempts to show distortion figures, on/of what?........DML's vary immensely in their design and construction, size, panel material and the way they are implemented : true NXT style or the Podium Loudspeaker approach etc.
Do us all a favor and read up on this technology so that you are aware of what it's all about before posting a meaningless distortion waterfall response.
I can happily say that I have built the real thing and am listening to it every day, loving every minute of it. That does not sound like a very high distortion loudspeaker does it?
jzagaja, ....interesting. The sound of brass and voice is very natural on my panels. Piano is incredible, tympani, drums : very scary
If it attempts to show distortion figures, on/of what?........DML's vary immensely in their design and construction, size, panel material and the way they are implemented : true NXT style or the Podium Loudspeaker approach etc.
Do us all a favor and read up on this technology so that you are aware of what it's all about before posting a meaningless distortion waterfall response.
I can happily say that I have built the real thing and am listening to it every day, loving every minute of it. That does not sound like a very high distortion loudspeaker does it?
jzagaja, ....interesting. The sound of brass and voice is very natural on my panels. Piano is incredible, tympani, drums : very scary
Maybe I'm wrong, willing to see BMR waterfall and built a good model. What I have now is an unbalanced 10 piezo element DML. Best way is to record instrument outdoors and play through DML in a reverberant room so you can really compare the real thing. The opinion comes from prof. Farina who has auditioned Opere Sonore and NXT. I'm afraid that longer decay is considered as highly detailed speaker.
el'OL, as I have discovered and somehow tried to make evident in my last posts is that the panels are very much dependant on your source components in the audio chain.
I have recordings that have acceptable highs when played on a particular amplifier/speaker combination. The panels indicate that this same recording has highs that are totally ****. This has been confirmed with other people's systems(some had lousy highs, some had o.k highs).
The way you position the panels and the size and dampening of your listening room will affect the highs.
On occasion, I have heard CD's and FM broadcasts that had what appeared to be exaggerated highs!........go figure
So to answer your question - yes, I am satisfied with the highs. They are presented to you very differently depending on a few factors mentioned, but when it's all happening, it's great!
The panels will also wow you with the midrange also. Most of the time they sound amazing and revealing - lots of micro detail(radio announcer's studio ''atmosphere'', switching in and out of tracks, equipment noise or hum......it's all there.
In comparison with my two way compression driver/15 inch bass horn system, the panels are far more revealing. Yes........you heard that right
The horns have a tendency to make everything sound the same - especially with valve amplification.Very strange indeed - and this was first noticed when I built a Gainclone to try on the horns.
The panels like solid state, no question. Valves through the panels are far too bass flabby and the top end and midrange seems veiled over.
I don't own the Audionote Ongaku with silver wired transformers so maybe it's not a fair comparison ???
jzagaja, I'm not sure I understand your point in your last post.
When you say longer decay, do you mean reverberation or ambiance?
Either way, NXT exciters on free floating panels has the ability to produce full reverberant effects and the natural decay of instruments played in a concert hall. This is one of the best features discovered with my panel version of NXT.
If you are using 10 piezos on a panel, you will have a very fast but limited bandwidth. Reverberation mainly occurs at lower frequencies to what the piezos will go down to? Correct me if I'm wrong.
I have recordings that have acceptable highs when played on a particular amplifier/speaker combination. The panels indicate that this same recording has highs that are totally ****. This has been confirmed with other people's systems(some had lousy highs, some had o.k highs).
The way you position the panels and the size and dampening of your listening room will affect the highs.
On occasion, I have heard CD's and FM broadcasts that had what appeared to be exaggerated highs!........go figure
So to answer your question - yes, I am satisfied with the highs. They are presented to you very differently depending on a few factors mentioned, but when it's all happening, it's great!The panels will also wow you with the midrange also. Most of the time they sound amazing and revealing - lots of micro detail(radio announcer's studio ''atmosphere'', switching in and out of tracks, equipment noise or hum......it's all there.
In comparison with my two way compression driver/15 inch bass horn system, the panels are far more revealing. Yes........you heard that right
The horns have a tendency to make everything sound the same - especially with valve amplification.Very strange indeed - and this was first noticed when I built a Gainclone to try on the horns.
The panels like solid state, no question. Valves through the panels are far too bass flabby and the top end and midrange seems veiled over.
I don't own the Audionote Ongaku with silver wired transformers so maybe it's not a fair comparison
???jzagaja, I'm not sure I understand your point in your last post.
When you say longer decay, do you mean reverberation or ambiance?
Either way, NXT exciters on free floating panels has the ability to produce full reverberant effects and the natural decay of instruments played in a concert hall. This is one of the best features discovered with my panel version of NXT.
If you are using 10 piezos on a panel, you will have a very fast but limited bandwidth. Reverberation mainly occurs at lower frequencies to what the piezos will go down to? Correct me if I'm wrong.
Ziggy,
Neither of above. For high speed sound low damping DMLs much shorter but still longer than most pistons. Ambiance comes from uncontrolled directivity.
That's the point NXT is good on long decay instruments/recordings, with some CDs they play well and with other quite questionable. My piezo won't play below 2kHz
Neither of above. For high speed sound low damping DMLs much shorter but still longer than most pistons. Ambiance comes from uncontrolled directivity.
That's the point NXT is good on long decay instruments/recordings, with some CDs they play well and with other quite questionable. My piezo won't play below 2kHz
jzagaja said:Aluminium decays much faster. I've tried adding the mass to monomorph brass plate and piezo plate but got contraction result to what I have wrote
Mass on piezo plate == higher modal density, higher first mode
Mass on brass plate == 6db louder
Today I phoned an old mechanical science professor who developed models for Stradivarius type violins and built prototype in 1985. There are two ways of lowering internal damping in wood: cold stretching and chemical modification.
Hi,
What is cold stretching?
Regards,
Peter
Prof. Skalmierski 30 years ago made a hypothesis that efficient and higher modal placement of Stradivarii violin is product of axial pre-load so that soundboard has to be stretched like a skin on a drum. Today violin makers bend wood with a heat that removes any stress. Recommendation is to use Euler elastic curves and cold bending. In his prototype he used recent method but with metal stretchers. He received award from the prime minster but no one was interested in a production. His colleague eng. Jerzy Kowalczuk used chemical treatment for similar results.
So if top plate lies freely or is axially stretched then damping decrement lowers and violins play louder.
Ziggy said:Mor den Siur, your attached image is so small it's useless(as is your posting).............CHOLERA!!!!!!(Polish swear word)
If it attempts to show distortion figures, on/of what?........DML's vary immensely in their design and construction, size, panel material and the way they are implemented : true NXT style or the Podium Loudspeaker approach etc.
Do us all a favor and read up on this technology so that you are aware of what it's all about before posting a meaningless distortion waterfall response.
I can happily say that I have built the real thing and am listening to it every day, loving every minute of it. That does not sound like a very high distortion loudspeaker does it?
jzagaja, ....interesting. The sound of brass and voice is very natural on my panels. Piano is incredible, tympani, drums : very scary
Easy man - peace
This was my comment for picturee, jzagaja posted in Post #222. Lets say bad joke...
I am very interested in this technology, but just waiting for holidays from my studies.
jzagaja said:
Hi jzagaja,
when lower damping is (may be) percepted as "more detailed",
this may be partly a deception of our hearing system ...
On the other hand: It is often stated, even with conventional
midrange drivers, that diaphragm materials with very high damping
can have little detail, especially at low listening levels.
I often wondered, if this is due to mechanical resistance not
being proportionial to the amplitude of diaphragm movement
even in breakup mode.
I believe that nonlinarities in the mechanical resistance of
diaphragm materials and suspension may cause a degradation in
fine dynamics and a loss of fine detail.
This may be the same for some highly resistive Materials
used in DML Panels.
If loss of low level detail is a problem with some highly
resistive materials it is difficult to have
fine dynamics + detail + short decay alltogether.
Maybe this is why lots of composites and structures are tried and
discussed in this area: Requirements are conflicting. There is no
obvious "best" solution.
To me personally one attractive approach seems to be combining
a flexible (non resistive) diaphragm material, which is capable
of linear movement, with a selective damping which is applied
to suspension and strategic points/areas of high velocity on
the diaphragm. This may be a way to introduce the required damping
with a minimum of nonlinearity.
Kind Regards
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