You know........this is weird, but the balsa wood lattice did cross my mind a while back
Reading up on it's use with guitar making, I think that this idea is definately feasible
It will be a lot of work and there is still the decision of what to laminate to the front and back, but WOW...........this is promising
!!!!
Reading up on it's use with guitar making, I think that this idea is definately feasible
It will be a lot of work and there is still the decision of what to laminate to the front and back, but WOW...........this is promising
!!!!jzagaja said:
I measured the mechanical linearity of a balsa board and it was perfect at least withing my measurement precision. I doubt this is very much different in other woods. As the other Oliver argued some posts above a non-linear behaviour of the damping could lead to a loss of fine dynamics (additional to the harmonic distortion).
LineArray said:
This correlates with my own experience that the German Physiks with titanium diaphragm is clearly ahead of the BMR with its synthetic diaphragm in this respect.
My horn compression drivers, enormous and expensive use titanium for the diaphragms(as do most).
Regardless of non linearities and sound resistance, there is no mistaking that you are listening to TITANIUM.........that I can assure you. It's a damned pain in the *** withi t's easily recognisable metalic tonality........even the best and most expensive drivers.
Aluminium and even phenolic diaphragms sound much more natural in my opinion. Paper has the edge over all materials......even old fashioned paper tweeters have been known to sound more real than soft dome/fabric/metal/kevlar etc.
Have a read of the attached link and then think about our analog world, make up and sounds around us and decide if we have ''tin ears''
Some of the best sounds Ihave heard have come from non-metallic drivers - they have no place in audio IMHO
It is important to remember, and I will repeat this once again..........we are not dealing with normal drivers.........these are DML panels where some rules just do not apply to normal cone type drivers
http://www.altmann.haan.de/byob/mother.htm
Regardless of non linearities and sound resistance, there is no mistaking that you are listening to TITANIUM.........that I can assure you. It's a damned pain in the *** withi t's easily recognisable metalic tonality........even the best and most expensive drivers.
Aluminium and even phenolic diaphragms sound much more natural in my opinion. Paper has the edge over all materials......even old fashioned paper tweeters have been known to sound more real than soft dome/fabric/metal/kevlar etc.
Have a read of the attached link and then think about our analog world, make up and sounds around us and decide if we have ''tin ears''
Some of the best sounds Ihave heard have come from non-metallic drivers - they have no place in audio IMHO
It is important to remember, and I will repeat this once again..........we are not dealing with normal drivers.........these are DML panels where some rules just do not apply to normal cone type drivers
http://www.altmann.haan.de/byob/mother.htm
No I have not heard these drivers. As good as they may be, they will still be forward radiators - not where I want to be which is why I started this thread.
Yes, there is a slight loss of detail in horns. The funny thing is that the NXT panels make this loss of detail more obvious. In other words, DML's can produce amazing detail - especially distant ambient detail which is lost on some other speaker systems.
Go figure............strange beasts for sure
Yes, there is a slight loss of detail in horns. The funny thing is that the NXT panels make this loss of detail more obvious. In other words, DML's can produce amazing detail - especially distant ambient detail which is lost on some other speaker systems.
Go figure............strange beasts for sure
The second lightest that is easily available is Abachi. I also tried this (1mm board) with piezos and it is not much better in transparency than balsa. Göbel use a 9 layer sandwich (just 1mm thick and I mean to remember that one step in the processing even needs a vacuum), I am sure they tried simpler structures with worse results, so I think that wood thing is out of reach for DIYers.jzagaja said:
??????jzagaja said:
Ziggy said:
Yes, there is a slight loss of detail in horns. The funny thing is that the NXT panels make this loss of detail more obvious. In other words, DML's can produce amazing detail - especially distant ambient detail which is lost on some other speaker systems.
Go figure............strange beasts for sure
@ziggy:
Some thoughts on that, i agree with your observations and i
am fairly puzzled too ...
Hi there,
summarizing what i have heard about the
possible virtues of DML, including the experience
with my own design, i can see these few points,
which can be achieved:
- good imaging, listener envelopment, sound
stage has realistic depth
- awareness of detail even at large distances
of the virtual sound source(s)
- crisp and fast impulse response
- sound can be "unobtrusive" in the best sense
And last but not least:
- Integration and placement in the listening
room can be fairly uncomplicated.
If you like, put "auditively" or "subjectively"
as prefix in front of each point.
All in all i would say this is how we want a
speaker to sound like. Maybe DML is a technology
which should be payed more attention to, even in
the high end scene.
I have some assumptions how a well designed DML
achieves these virtues:
- Detail is achieved because the spectral
fingerprints of indirect sound(s) bouncing
from the room walls resemble(s) the spectral
fingerprint of the direct sound. The DML
radiates in a diffuse manner but does not
beam at higher frequencies. The polar
radiation pattern varies rather
smooth with frequency. Copies of
sounds bouncing from the wall can be
identified as copies of the direct sounds,
thereby possibly emphasizing
the notion of reality and detail with adequate
energy in the upper octaves.
- Envelopment, depth and realistic sound stage
may be supported by the diffuse soundfield,
which is especially radiated off axis.
The diffuse structure of the indirect sound
field excites the (normally small) listening
(living) room in a way to affect room
acoustics better as it is.
Common dynamic multiway speakers are more
revealing concerning the fact,
that we usually hear in rooms which are simply
to small to have good room acoustics.
This is because diaphragms of dynamic multiway
speakers are smaller compared
to wavelengh and more pistonic acting
than DML.
- Subjectively a "crisp" flavour of a drumbeat
or a piano attack may not be achieved solely
by an acceptable step/impulse response in an
anechoic chamer alone.
In a good concert hall (and a good recording
resembling that hall) there is the direct
sound with the typical steep transients,
then there are early and later reflections
which typically have smoother slope.
A common multiway speaker may create
reflections in the listening room, which
are early and rather steep, especially when
naked walls are in proximity to the speaker.
Those reflections do not contribute to the
original sound perceprively, but are
disturbing, especially when the spectral
fingerprint of the reflections is deformed
due to a strongly frequency dependent
radiation pattern of the speaker.
My preliminary conclusion:
While not superior obviously compared to
conventional dynamic multiway systems
concerning transient response and phase coherence,
the DML has acceptable behaviour in these areas
when constructed properly. Polar radiation pattern
and diffuse off axis sound field contribute to an
acoustic integration into the common living room,
which is superior to most dynamic multiway designs.
The subjective qualities of clarity, spatial
image and depth can be achieved in astonishing
quality with a system which is far from beeing
perfect from a measurement point of view.
A well built DML may be a very "physiological"
system, producing little disturbance when
evaluated physiologically and in terms of
room acoustic measures.
Best ,
Oliver
Endgrain balsa is stiffer than parralell grain in a laminate.
The crushing strength of the end grain is much much higher, and that is what is important here.
If you try to bend a laminate with parralell grain balsa in it, the balsa will be crushed easily compared to the endgrain wich resists crushing.
The lack of transparency you have experienced might be caused by the softness of the balsa parralell to the grain direction.
Sound transmission in wood is much better along the grain, so more energy is going to reach the other side of the panel using the end grain.
If you want the stiffest possible laminate the most important parameter for the skins is the resistance to stretching, and in the core- resistance to crushing is the most important.
A lattice made of end grain balsa covered with a thin layer of carbon fiber seems like a good option for light weight.
Peter
The crushing strength of the end grain is much much higher, and that is what is important here.
If you try to bend a laminate with parralell grain balsa in it, the balsa will be crushed easily compared to the endgrain wich resists crushing.
The lack of transparency you have experienced might be caused by the softness of the balsa parralell to the grain direction.
Sound transmission in wood is much better along the grain, so more energy is going to reach the other side of the panel using the end grain.
If you want the stiffest possible laminate the most important parameter for the skins is the resistance to stretching, and in the core- resistance to crushing is the most important.
A lattice made of end grain balsa covered with a thin layer of carbon fiber seems like a good option for light weight.
Peter
LineArray.......Oliver,
YOU HAVE HIT THE NAIL RIGHT ON THE HEAD .....so to speak.
I agree with you 100%.
The DML sound is exactly as you have described. I find myself forgetting that I am listening to electronics and just concentrate on the music.........that's what it's all about
When the DML panels so clearly establish that a kettle drum is made of copper with a skin stretched accross it, and hit by felt beaters, your jaw just drops to the ground in amazement.
The horns have NOT been able to do this. I suspect that this is due to a ''crossover network''
that is only simple but destructively audible! Secondly there is a transition between a large and slow 15 inch high guauss woofer to a titanium domed driver - can never really blend together with any coherence.
Anyone who thinks that combining two different types of materials to realistically reproduce sound tonalities and important tonal clues are only fooling themselves
YOU HAVE HIT THE NAIL RIGHT ON THE HEAD .....so to speak.
I agree with you 100%.
The DML sound is exactly as you have described. I find myself forgetting that I am listening to electronics and just concentrate on the music.........that's what it's all about
When the DML panels so clearly establish that a kettle drum is made of copper with a skin stretched accross it, and hit by felt beaters, your jaw just drops to the ground in amazement.
The horns have NOT been able to do this. I suspect that this is due to a ''crossover network''
that is only simple but destructively audible! Secondly there is a transition between a large and slow 15 inch high guauss woofer to a titanium domed driver - can never really blend together with any coherence.Anyone who thinks that combining two different types of materials to realistically reproduce sound tonalities and important tonal clues are only fooling themselves
Hi ziggy,
i have not read the whole thread, but is there a brief description
of your horn system, which you use to compare the DML with ?
From my experience i see no problem in combining diaphragms
of different material in a multiway, not in itself.
But choosing X-over frequencies wisely (not only technically,
but also physiologically) and keep the radiation angle at X-over
as constant as possible is important for a speaker to sound
homogenously.
I know e.g. from a developer using a larger dome tweeter
as neccesary, to get more homogeneity in a 2-Way, even when
loosing brillance at the top end.
Is your tweeter horn loaded too ?
Oliver
i have not read the whole thread, but is there a brief description
of your horn system, which you use to compare the DML with ?
From my experience i see no problem in combining diaphragms
of different material in a multiway, not in itself.
But choosing X-over frequencies wisely (not only technically,
but also physiologically) and keep the radiation angle at X-over
as constant as possible is important for a speaker to sound
homogenously.
I know e.g. from a developer using a larger dome tweeter
as neccesary, to get more homogeneity in a 2-Way, even when
loosing brillance at the top end.
Is your tweeter horn loaded too ?
Oliver
Hi Line Array. There is a photo of my horn system next to the panel prototypes on page 4, post 79 in this thread.
The crosssover is a simple 6db choke and capacitor(large polypropylene in oil) crossed over at about 800hz.
The fibreglass horn is made by AZZURA HORNS here in West Australia and are designed by Le Cleach.
The compression drivers are huge : Selenium D400 TI(8 inchhes diameter!!).
The bass bins are a Fane front horn/reflex design but are an Altec knock off (can't remember the cabinet model number). The 15 inch drivers are old Australian made ETONE 805's that are no longer manufactured. Unfortunately the bass bins are not correct for the bass reflex ports and the Etone's - there is a mismatch there(the Etone's require a very small enclosure to work as bass reflex).They operate with the back's off for that matter alone.
I have tried every crossover point, attenuation,positioning, phasing,using complex crossovers, simple crossovers,you name it and I've been there.
Don't get me wrong they can and do sound great at their current configuration which I have settled on - the crossover frequency and 9 db attenuation of the mid/high horn.
I have found that they do not require a tweeter on the Le Cleach horns which are 24 inches in diameter and only about 12-14 inches deep due to the 2 inch coupling and the design of the flare.The high frequency output is more than adequate on such a large 4 inch diaphragm - surprisingly linear.
Any attempt to add a super tweeter or just a tweeter of any kind never had any positive effect(maybe a bit more ''air'', but that was debatable) and I can hear to 16k !
What sorts the men from the boys as far as I'm concerned is the ''full range coherence'' that the horns don't have but the DML's do. Not just that, but as I mentioned, the DML's have a realism and lightening fast transient detail reproduction that just isn't there with the horns. The horns sound muddy and fake in comparison.
Add to that the DML's ability to place you inside the recording venue and dissappear as if there were no speakers at all - irresistable!
This is very noticeable in my room. Even el-cheapo full range drivers can sound amazing in there.
The crosssover is a simple 6db choke and capacitor(large polypropylene in oil) crossed over at about 800hz.
The fibreglass horn is made by AZZURA HORNS here in West Australia and are designed by Le Cleach.
The compression drivers are huge : Selenium D400 TI(8 inchhes diameter!!).
The bass bins are a Fane front horn/reflex design but are an Altec knock off (can't remember the cabinet model number). The 15 inch drivers are old Australian made ETONE 805's that are no longer manufactured. Unfortunately the bass bins are not correct for the bass reflex ports and the Etone's - there is a mismatch there(the Etone's require a very small enclosure to work as bass reflex).They operate with the back's off for that matter alone.
I have tried every crossover point, attenuation,positioning, phasing,using complex crossovers, simple crossovers,you name it and I've been there.
Don't get me wrong they can and do sound great at their current configuration which I have settled on - the crossover frequency and 9 db attenuation of the mid/high horn.
I have found that they do not require a tweeter on the Le Cleach horns which are 24 inches in diameter and only about 12-14 inches deep due to the 2 inch coupling and the design of the flare.The high frequency output is more than adequate on such a large 4 inch diaphragm - surprisingly linear.
Any attempt to add a super tweeter or just a tweeter of any kind never had any positive effect(maybe a bit more ''air'', but that was debatable) and I can hear to 16k !
What sorts the men from the boys as far as I'm concerned is the ''full range coherence'' that the horns don't have but the DML's do. Not just that, but as I mentioned, the DML's have a realism and lightening fast transient detail reproduction that just isn't there with the horns. The horns sound muddy and fake in comparison.
Add to that the DML's ability to place you inside the recording venue and dissappear as if there were no speakers at all - irresistable!
This is very noticeable in my room. Even el-cheapo full range drivers can sound amazing in there.
Hi Ziggy,
from my gut feeling i would say that a 15 inch driver
cannot load a horn properly up to 800 Hz due to
cone breakup and narrowing of radiation.
Not to mention the overlap region up to N octaves above
X-over frequency.
When using 6db slope:
Is the driver's voice coil inductivity compensated ?
I guess what happens in that horn - beginning in the throat -
is pure chaos in upper midrange, no chance to address that
with a crossover. Every crossover would be wrong, no chance
to compensate those effects.
What happens at lower X-over ? At least 1 octave lower would
be desirable IMO , but i don't know the limitations of your
tweeter/horn combination. I guess you've "already been there" as you said.
Furthermore i would experiment with lining the bass
horn/throat with a soft material, maybe some kind of carpet,
and shape the driver/throat section in a way to avoid discontinuities in the cross sectional area.
Maybe dividing the bass horn into separate sectors or some
kind of phase plug could help.
I know, this is normally not the kind of things horn purists want
to hear ...
Another question: Do you really need a high compression ratio
in the tweeter horn's chamber ? I never felt, that high ratio compression chambers deliver good sound.
An old friend of mine and myself were tweaking and reengineering
a pair of Klipschorns over a decade before he gave them away,
these are some experiences from that.
Best,
Oliver
from my gut feeling i would say that a 15 inch driver
cannot load a horn properly up to 800 Hz due to
cone breakup and narrowing of radiation.
Not to mention the overlap region up to N octaves above
X-over frequency.
When using 6db slope:
Is the driver's voice coil inductivity compensated ?
I guess what happens in that horn - beginning in the throat -
is pure chaos in upper midrange, no chance to address that
with a crossover. Every crossover would be wrong, no chance
to compensate those effects.
What happens at lower X-over ? At least 1 octave lower would
be desirable IMO , but i don't know the limitations of your
tweeter/horn combination. I guess you've "already been there" as you said.
Furthermore i would experiment with lining the bass
horn/throat with a soft material, maybe some kind of carpet,
and shape the driver/throat section in a way to avoid discontinuities in the cross sectional area.
Maybe dividing the bass horn into separate sectors or some
kind of phase plug could help.
I know, this is normally not the kind of things horn purists want
to hear ...
Another question: Do you really need a high compression ratio
in the tweeter horn's chamber ? I never felt, that high ratio compression chambers deliver good sound.
An old friend of mine and myself were tweaking and reengineering
a pair of Klipschorns over a decade before he gave them away,
these are some experiences from that.
Best,
Oliver
Hi LineArray.
Thanks for your input and suggestions.
I think that the front horn on the bass driver is one of many problems including the giant resonant cabinet it sits in.
Having now discovered what a boxless speaker sounds like, and still have at times(with the right amplifier and source material) retained frightening dynamics, it's very hard to go back to the horns and wooden boxes, throat interactions etc.
To me, it's a waste of effort for non guarenteed improvements. I can make them sound different and go crazy by going overboard with dampeneing and other means as you suggest, but unfortunately I have gone down this road and found snake oil In other words, what should have made a difference(including crossover designs especially designed for horns), never did after long sessions on the work bench.
To this day, I can connect the horns up and play music, whether FM radio or CD while reading a magazine or article, and find myself being constantly distracted and questioning my crossover point or whatever.......allways feeling that something is not right.
This does not happen with the DML's.
The only time I look up or take note of the sound is when I am amazed or stunned by how good the recording at the time sounds.
I now tap my foot listening to music of any kind.........a good sign that indicates musicality and not electronic simulation
Thanks for your input and suggestions.
I think that the front horn on the bass driver is one of many problems including the giant resonant cabinet it sits in.
Having now discovered what a boxless speaker sounds like, and still have at times(with the right amplifier and source material) retained frightening dynamics, it's very hard to go back to the horns and wooden boxes, throat interactions etc.
To me, it's a waste of effort for non guarenteed improvements. I can make them sound different and go crazy by going overboard with dampeneing and other means as you suggest, but unfortunately I have gone down this road and found snake oil
In other words, what should have made a difference(including crossover designs especially designed for horns), never did after long sessions on the work bench.To this day, I can connect the horns up and play music, whether FM radio or CD while reading a magazine or article, and find myself being constantly distracted and questioning my crossover point or whatever.......allways feeling that something is not right.
This does not happen with the DML's.
The only time I look up or take note of the sound is when I am amazed or stunned by how good the recording at the time sounds.
I now tap my foot listening to music of any kind.........a good sign that indicates musicality and not electronic simulation
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.