Can "second harmonic distortion" be judged from the frequency response graph?
or any measurement data that can be seen
How to judge from the data?
Thank you so much for sharing~
Because I use DSP to do frequency crossover
If the "ears" and "irregular" shapes can increase the smoothness of the "low-mid frequency"
That would be a good way too
I saw the tweeter of "Bertagni" was also placed in the corner (2-way)
I just found out that it has some holes in it
So are they using these holes for some kind of correction?
Does anyone know the purpose of the big hole in the lower right corner?
Last edited:
The only way to judge is with your ears. The common misconception is that distortion is bad and that is usually true only if the distortion levels are high. But at low levels of distortion there is only a slight discernible difference and then it comes to personal preference.
For example a phonograph/record player has more distortion then a laser disc player but some prefer the sound of the phonograph.
For example a phonograph/record player has more distortion then a laser disc player but some prefer the sound of the phonograph.
I've been discussing this with my friends for a while now.
Similar curves have the same sense of hearing in the general direction
But different materials, magnetic circuits, circuits
It actually sounds a little different
In the case of low distortion, of course, it depends on personal preference
I've been thinking about this for a while
High quality tweeters seem to be of the film type
Mainly to do micro-vibration in a small area
If it is to be used on DML, it seems that it can only be ultra-thin, ultra-light and ultra-hard
In fact, the end result is the same as other types of tweeters
I think the advantage of DML is only in the low and medium frequencies
So Yamaha directly replaced the treble part with a tweeter
Instead of using Bertagni's approach
What are your thoughts on the above?
Welcome everyone to reply and share thanks
High quality tweeters seem to be of the film type
Mainly to do micro-vibration in a small area
If it is to be used on DML, it seems that it can only be ultra-thin, ultra-light and ultra-hard
In fact, the end result is the same as other types of tweeters
I think the advantage of DML is only in the low and medium frequencies
So Yamaha directly replaced the treble part with a tweeter
Instead of using Bertagni's approach
What are your thoughts on the above?
Welcome everyone to reply and share thanks
The holes you circled in red are weights. The weights can help lessen the degree of intermodulation between the two exciters. The big hole you circled in blue acts like a bass port releasing stored up energy and or redirecting the stored energy away from the high frequency exciter.
Correct. Instead of using a second exciter for the high frequencies like Bertagni, Yamaha just utilized a conventional tweeter as its way more easier to implement in ones design.
DML's strong suit is the midrange and midbass. From 100hz-2khz. A powered sub can be used for frequencies below 100hz while a conventional tweeter can be used for frequencies above 2khz.
Promotion of Technology utilising a modern concept for design that creates a range of products that are requiring wood to be used, is very Valuable to Tree Population. If the Industry takes off to produce such designs more TREES are required to be grown and sustainably managed.
Densified Woods are most likely to supersede many roles that Ore and Mineral Materials have been required to be mined for, to extract the base materials for the products in use today.
Densified Woods are most likely to supersede many roles that Ore and Mineral Materials have been required to be mined for, to extract the base materials for the products in use today.
Thanks Christian,
I do have sparse outlines of the materials I first used, but not too much detail.
I was using 15mm, 17kg/m3 EPS, skinned with ordinary brown Kraft paper (the real stuff with a 'K', not a 'c'.) The paper is approximately 0.065mm thick and 64g/m2.
The EPS panel by itself has areal mass of 255g/m2.
After being skinned and glued (with ordinary cold wood glue, slightly diluted to make the glue spread easier) the cured mass of the laminate was 38kg/m3, with a final areal mass of 574g/m2.
Doing the arithmetic, it turns out that the cured mass of glue is about 220g per side (wow that's a LOT!!
)Here's the FR of the above in a 500 x 760mm panel, secured hard around the long edges, with a Tectonic driver (TEAX32C30-4) in the classic position.
The reasons I did not continue with this design are primarily because the Tectonic drivers were rubbing and buzzing at this stage, and I had to continuously take them apart (they are serviceable) and re-glue their supports. Also, as mentioned, those drivers were quite expensive, although I think they have come down a bit in price.
I also did not want to use paper/EPS in a robust, road-based touring environment where things get chucked around quite freely. I'd rather use harder materials and rely on multiple drivers and brutal wattage to get the SPL I want.
Last edited:
Not generally, no.
Since distortion is generally very low in a good loudspeaker, (less than 5 parts in 1000 for a good loudspeaker), it's unlikely that you would pick up the distortion in an FR graph.
Of course there are those who claim that distortion is good in hifi 🤦♂️ but that's probably because they have never heard a really good system at play, and they probably think that their personal tastes carry more weight that that of experienced recording engineers. Or maybe they're just blown away by their little Bluetooth USB speakers.
That's actually one of the problems with really good systems: Amateurs are so used to cheap sound that they will choose the worst, most distorted option almost every time in blind tests.
Different things are popular in each age
There is no good or bad, each has its own preferences
There was a period of time when "vinyl records" also declined
But recently, some people have begun to collect and use
The past memories are the best
So to some people their preferences are "stuff in memory"
Which curve is the best to listen to is still inconclusive among headphone fans
The curves of each brand are very different
So then I think the owner of the speaker likes itThat's the best
Of course, we like to play with measurement tools and think this is the best
But I think it's a joy of the learning process
At every stage of life, you are free to play and learn whatever you want
So it doesn't matter whether it's good or bad, just be happy
Thank you for sharing~
Last edited:
I think high frequency is micro vibration
It cannot produce large area micro vibration
Excluding AMT (Air Motion Transformer, Heil Tweeter)
So it should be right to install many Exciters
More coils allow more areas to generate high-frequency sound
But when listening closely
I found that the coil was slightly noisy when it was reciprocating at high frequency
So it should be more perfect to use the tweeter
Having one coil responsible for too much of the frequency range would seem to be slightly noisy right?
So I'm also hesitant to try multiple coils!?
This is my current thinking
Welcome everyone to share your experience
Thank you for sharing and replying~
Last edited:
I'm not sure what you mean by micro vibration.
The voice coils have a maximum excursion of around 3mm. This would be for max SPL at, say, 100Hz depending on your panel dimensions.
Only a fraction of this excursion would be required to generate the same SPL at 1khz and even a smaller fraction at 10khz. ALL frequencies are micro-vibrations depending how loud you want to go. And the whole panel vibrates in a quasi-random fashion if there's no damping involved. The better the positioning of the exciter, the more parts of the panel will vibrate.
You will most certainly not get better HF simply by using more exciters. You will get more power handling, and more SPL, and if you get the positioning right then maybe a flatter response curve, and maybe a bit more HF. But not as a rule.
If it's not mounted to a panel, then the voice coil should be absolutely dead quiet when driving any frequency, except for a little bit of HF air action coming from the spider suspension, and also a little bit from the flat glue ring that sticks to the panel. At high power you might also notice some distortion but which is usually hidden by the SPL coming from the panel.
If you want to use a cone tweeter then you are going straight back to the problems inherent in cone speakers, i.e. beaming, lobing, dead spots, hot spots, bad imaging, shallow sound stage and a very small sweet spot. Of course, you will also need a cross-over and you need to try keep the cross-over frequency away from the 1khz-4khz band.
A tweeter on a DML panel is not a very elegant solution. (Yes I know Tectonic have used a planar tweeter (or is it a dipole ribbon?) in some of their panels, and I would concede that's an okay-enough compromise. But it still needs a cross-over!)
I would like to know what is meant by "noisy" noise. I see this word is used a lot on the forum. Is this what is meant instead of distortion? Or is it mechanical buzzing and rattling? Rubbing? Over-excursion?
Is fiberglass and resin part of your DML cookbook?Hey teacher, leave them trees alone.
Distortion is not an information of the FR curve by itself as the FR is the linear aspect of the transfer function but tools like REW thanks to the logsweep measurement has the capability to mesure it. You can add easily the different distortion orders or the total distortion upon the FR;
Not really linked to DML but I remember a paper from Jean Hiraga in the french magazine "L'Audiophile" trying to make a relation between the distortion spectrum and how an amplifier is appreciated. The reference was a 300B one with a regular decrease in the distortion spectrum including a high level of H2 (second order distortion).
Which Yamaha model is this loudspeaker? Seems the "DML" and the tweeter are firing in same direction (not the case of other models being 3 ways as other Yamaha models with such "natural sound" or ear speakers).
I don't think there are specific needs for a tweeter because used with a DML..
The tweeter introduces :
- a crossover with the question linked to that (phase, distance between the source center...)
- a big difference in the radiation pattern. No HF to the rear side, a reduction of the radiation angle when the frequency increases.
Seems additional weights are in most of the commercial DML. One of their role is to modify the modes and smooth the FR.
Audiofrenzy,
You have deeply studied the Bertagny and used their solutions.
What is the reason of the additional tweeter? Is its band limted because of the optimisation of the bass/mid despite the high density EPS?
We often see the back of the speaker to show what is inside. Is it a true open back speaker or is there some damping/attenuation material?