XXHighEnd

Ultimate Audio Playback => Your thoughts about the Sound Quality => Topic started by: PeterSt on August 14, 2007, 10:41:12 am



Title: What have I done ...
Post by: PeterSt on August 14, 2007, 10:41:12 am

Theory became practice, that's the least I could say. Man, what have I done.

Usually I leave it to you out there to rave (or not) about something, but this time I happily do it myself;
If I counted right, this now is the fifth time in the year of development of XX that the improvement on sound quality is so huge, that it now is 5 times in another leage or however to say that (the first version was already better than CD players).

My Q1 slider is at 7, Absolute Phase is normal.

Okay, what were my theories hence what to achieve with this 0.9i version ? Eliminate horn resonance.
As it appears now (I am almost certain of that), the "horn resonance" as a property of front loaded horns might exist by itself, but as with more anomalies in life, you have to wake it up to let it bother you.

Horn resonance my *ss I say now, and obviously I must have thought that already when I started this little project last saturday (also see http://www.phasure.com/index.php?topic=159.0 which was the base for it).

A typicle characteristic of a front loaded horn is its relative enormeous efficiency (the ones I use are 115dB). Although I must be careful not to express things I know nothing about, one of the reasons a horn can be so efficient is because of its "beaming" characteristic. So, it beams the sound towards you instead of spreading it around, so all the energy goes towards you instead of to your walls. But there is a kind of drawback (and please note these ar MY words and not official, but anywone going against my words just has a disagreement with me) :

The mouth (actually the throat) of such a very efficient horn is very small. It depends on the horn of course, but mine are 2 inches diameter I think.
Depending on the frequency the horn is allowed to carry, such a small diameter is prone to various problems, thinking of the wavelength exceeding that diameter and blablabla, but my point with the "horn resonance" is about the reflections in that small throat.
The throat has a length, and throughout the that length the waves have to pass, not disturbing eachother. Well, I can tell you, there's even turbulence in there ...

Now I fall back to a by now more known explicit principle of mine : the standing waves. I do this on order to "visualize" what is happening really;

Those withg fine playback systems know what makes XXHighEnd benefit most : the low frequency (only those ? :nea:) will disappear from the room. No matter how untreated and "lousy" your room is to this aspect ... they disappear. But do they really ?
No, they do not, because they still can be measured. But without XXHighEnd they are so much profound, that they make more music than your music. So there is a tolerance level. So with the "standing waves" inside the horn's mouth ...

One of the things happening in a horn, will be the "pushing" of the sound waves. Remember, they can't go anywhere but straight forward. In my horns anyway, there is a 6 inch (15cm) or so with paralell walls before the throat gets wider. Of course, the speed of sound remains the same always (I mean, it's not depending on frequency or volume (better : SPL)), but still we can imagine that the previous sent out wave is just ahead of the next, and theoretically there will be some "pushing". Compare this with a normal 180 degrees radiating driver (diaphragm) into free air, and you can feel it's different.
Because of the waves bouncing onto the wall of the throat, they will theoretically slow down, bounce against the opposite wall and form a barrier for the next wave coming up, that possibly not bouncing the walls - so trying to catch up with the previous.

Some would say the principles of this are wrong ...
and again : these are *my* descriptions, and I really don't care what others say or how it supposedly really is; I "work" with my descriptions

But things appear to be different for results ...
Like with the standing wave thing, and the bass traps etc. that should remove them, instead we can also not wakeup the beast. :clapping:

When listening closely, or with much attention if you like, you can hear when things go wrong with music playback from a horn. And I say it in advance : with any speaker really. It goes wrong when the sounds are squary. Ha ! good one ! not. Because what we perceive is squary just because of the distortion !

So now it is a matter of what comes first : the squary sound creating distortion, or the distortion making the sound squary.
I can tell you, they work together ...

Let's first define the distortion we are talking about.
This is very very difficult to "make up", and let's say it took me 5 minutes to perceive it, but another year to make it clear to myself.

- A trumpet becomes more trumpet like;
- Timbre is more expressed;
- Highs from cymbals become more expressed;
- More detail is perceived;
- More fresh sound in general.

But wait a minute Peter, you didn't mention distortions here ...
Hahaha, yes I did ... :grazy: Read again :

- A saxophone sounds like a trumpet. I fact all metal blown instruments with sibilance do.
- Male voices have unreal square timbre;
- At higher volumes and specific frequencies cymbals are perceived as pure distortion;
- Unbalanced fresh highs.

So here we are. Distortion all over the place.
But mind you, this "distortion" is very much acceptable in most cases, with which I mean that in most cases you won't know the difference with real life. A male with "unreal square timbre" ... how to tell if you don't know the man ? and worse : how to tell if you heard him singing through speakers only anyway ? Yes, think about that.
There is more in this than you might believe, and only few people will have ever heard the difference by explicit tweaking. I did, at working at the xover of horn speakers (well, out Bert did, but I was there), and just by tweaking the xover for better or for worse, a thing like timbre changes all the way. From completely gone to full square.
So, once you know the differences which can be made, you have learned how all can be attacked.

But also you have learned to hear it. And in the end you hear it everywhere. But also it is still perceived as rather normal, because it can't be different anyway ...

So what happened with 0.9i for results on this ?

The obvious :innocent: the distortions have gone.
The result is creepy;

First of all, now there is balance balance and more balance. This can be sensed all over.

Then I had to create a new phenomenon for myself on audio playback : fragile. Fragile not in the sense of breakable (or just not broken) but with a finesse where "finesse" is far too rough.
The freshness what I was used to as coming from a horn speaker has changed into sprankling. The harmonics of bells etc. now are not overwhelmed by the over freshness of a cymbal.

Square natural tones (what about negro males) do not destroy the "background tones" like form a cymbal singing at the same time.

There's one phenomenon coming over me each other minute : water like. The horns seem to drool water now. Hard to express better.

There is a stiffness in the silky tones. This one is difficult too. Silky would be true, but silk also is weak. Now the silk is not weak anymore.

There is a so much "founding" bass now. With this I mean that you visualize the bass underneath everything, the further sounds not riding on that bass, but floating above it. The bass now can separate from the rest. It makes it all "deep down earth" bass. Bass can have color.
Individual bass vibes are inifitly better expressed now.

Generally, it now seems that all music creates tears in your eyes. Okay, mine;
Where before you had to have the mood of getting into the music, including the music had to allow for it, now you can't get DEtached anymore. Okay, me.
All is so much homogeneous, that with each and every song you realize that someone has been thinking that song over for many days or more. This is so strong that even right now I have tears in my eyes only because of thinking of last night (no music plays currently). Wow.

Already before (earlier version) I noticed that a distorting guitar would not destroy the complete somg anymore, because it would be in its own corner from then on, not disturning its neighbour players. Now here a major change has happened :
The distorting guitar, producing square waves (!) is now not destroying its own sound anymore. Like the example of the square male voice  who could destroy cymbals.
Rough heavy synthesizers before layd a grey sound over everyting. Now it's just their own square waves you hear (nos-DAC only !!).

In gerenal you can say that not any instrument can smash out the other. I did not know this really, but it now appears this was so. Any ferm drum hit would destroy its surrounding at the moment of the hit. Not so anymore.

The for me best of all is this :
Where I listened to versions of XXHighEnd with so much crazy detail that it became unbearable, now all that detail is back or there is even more.
It is very hard to explain what went wrong with an earlier version, because detail is detail and detail is good. But it was not. It was a version that let fall apart the instrument, as Gerner could describe it so beautifully. We listened to the individual strings of a guitar (interesting) but not to the guitar anymore.
In this version with my setting all the detail iss there, but not over expressed. Again hard to explain how it now is better, but strangely enough there is even more detail than ever before, but now it is good detail. Most probably because the detail now is accompanied with "body". A sort of : the detail has a base tone, and the harmonics of it let you perceive the detail as a whole; in the earlier version the base tone was lacking, and the harmonics were the only tones coming to you. I don't know really.

Horn speakers only ... No !!!

I did not change the properties of the horn speaker. They remain as is, just like the room remained as is, but standing waves disappeared anyway.
Again I say that obviously I knew this in advance, at starting this small but ever so important project. All in other words : this has few to do with horn speakers. But in there is a beast that can be awakened. Don't.

The obvious question is how do we wakeup that beast then.
The answer is more simple than applied :

With digital sourced music we deal with squares. Yeah yeah, you know.
Ha ! no you don't. Not what I mean. :no:

What you probably *do* know, is that the digital data is comprised of volume steps, lateron applied to Volts. It really is volume only, that implying frequency (combined with the time domain -> time proceeds, and volume changes, for CD data 44100 times per second).
What you also (or even better) know, is that the possible volume steps are 65536 for normal CD data. Half of that is for plus Volts, half for minus. When time proceeds, this creates the "wave". This wave really looks the same on the computer screen in digital form, as it would look on a scope in analogue form. If really 1:1 applied, it is.

What you most probably don't know, is how jitter impeeds square waves. Or more square then original. Oh, maybe you knew it, but not me, and that's what came to me in creating 0.9i.
Jitter is the skipping (or repeating) of (in our case) audio samples. When time proceeds, a next volume step is applied. Let's say that for a certain (composed) tone the step rises with 50 (out of the total of 65536). So from one sample to the other, the volume rises with 50. Now, since this coincidentally is a squarish tone like from a trumpet, and where we *know* that squares tend to rise very steep (a real square would try to do it in 0,0000ms which physically nor electornically does not exist) at the next sample another 50 would be added. what is jitter to this respect ?

As said, the skipping and repeating of samples. Hmm ... what happens to our volume steps ?
They want to rise with 50-50-50-50-50, but instead they go like 50-0-100-0-100
So what really happened is that we created a double sized square. Thanks very much.
(note that in practice my sample is a bit overdone, because jitter acts more randomly than I proposed).

Now things become VERY important and quite a few properties add up, most probaly in a more than lineair way :

1. Squares have more energy than a sine (probably the most important aspect).
2. Squares create aliases. This means a square can be found back audibly somewhere else in the spectrum (not good !). Do note that for a trumpet this is just real life. So, the harmonics of it (hence aliases !) will appear in mid air. This is how we appreciate a trumpet !
3. Squares in the analogue domain scratch echother, unlike sines which slide along eachother.
4. In a horn the additional energy can't escape and will bounce to the horn wall.

Mind number 4 : Additional energy ...
But also think of the diaphragms where the additional energy was already put to ... Don't forget, it emerges in the DAC ...
So possibly (or most probably) a horn is more prone to these anomalies than a normal radiating speaker, but a normal speaker would suffer form the exact same in the base ...

By eliminating the additional squares, you loose the anomalies. Simple !!
So, that's it.
:lol:

It is not all *that* easy of course, because the only physical property to "manipulate" would be jitter. Yeah, well, that's exactly what XXHighEnd attacks. Jitter.

:bye:

Lastly, a bit off topic, but for you good to recognize things. I learned them from perceived better or worse playback throughout times;

When the accuracy is better, one of the first things you'd notice is flanger. The more flanger, the more accurate the playback is.
Flanger is the slowly overall increasing and decreasing of volume. The Leslie (organ) became famous for it.

When accuracy is better, detuned voices become obvious.
This is a very very strange phenomenon, but just true. Like with the flanger, it is just my own notices;
When an instrument is detuned, and then merely *temporarily* detuned (like a singer seeking for the right key), this suddenly becomes VERY obvious.
In the end the principle would be the same as with flanger, because it is about slowly changing ... ALWAYS VOLUME. Haha. Think of what I said before : the only thing really changing is volume. Frequency (tuning) is just a derival of that, implied by proceeding time. So that both flanger and detuning come together seems logic.

:bye: Peter :bye:



PS: Didn't feel like looking for typos in here. Sorry.


Title: Re: What have I done ...
Post by: Gerner on August 14, 2007, 11:06:11 am
Ha ha ha Peter...

One could beleive we syncronized our posts. But we really didn't.

So with the same observations at "even" the same Q setting, it's twice as objective what we write compared to the past where nothing were written. Jihaaaa

Gerner  8)


Title: Re: What have I done ...
Post by: PeterSt on August 14, 2007, 11:11:07 am
No, I really did not read your post !
So we both landed at 7 he !?

I'll respond to your post soon.


Title: Re: What have I done ...
Post by: BertD on August 14, 2007, 11:28:26 pm
Congratulations Peter....never heard a digital source sounding soooooo smooth without loosing any detail and without adding any edges.

Another reason to crank up the volume a bit more...  ;)

Bert


Title: Re: What have I done ...
Post by: Chris V on August 15, 2007, 12:16:13 am
Well done Peter, with the release of 0.9i, XXhighEnd is really cooking :veryhappy: :veryhappy:.

My life is too busy at present to sit for prolonged periods evaluating what is happening to frequency responses, sound staging etc, but I do really appreciate those people that give us the details.

My main criteria at present is to engage emotionally with any music I listen to, whether it is by tapping a foot, wanting to dance, sing, or by having the music affect the mood I am in.

Early days, XX satisfied all the necessary Hi-Fi criteria enough to make me part with a pretty expensive CDP.

Version 0.9i allows me to dial-in maximum emotional involvement. I have never enjoyed home Hi-Fi this much in the 35 years I have been in the hobby. :drinks: :drinks:

Rear loaded Lowthers (DX4s) are wonderful drivers when operated in their optimum window, turn them up too loud and the sound goes from magic to confused. For the first time I can play loud without feeling as if I have been 10 rounds with a heavyweight boxer.

Here is the final testament. The sound of CD now comfortably exceeds the sound of vinyl using my Linn Sondek, Ittok etc. By the end of this year the record deck, phono stage and all vinyl will be gone.
It don't get much better than that. :goodjob: :goodjob: :goodjob:


Title: Re: What have I done ...
Post by: SeVeReD on August 15, 2007, 12:17:41 am
I am having loads of slider fun with this player... is there a correct setting? maybe... maybe not... I think I may as well be asking, Is there an absolute correct recording?