Orelo MKII Sub-low Specs

[PeterSt]

This is a first post in this new forum board for the Orelino and Orelo MKII loudspeaker, designed and produced with huge effort by BD-Design (Bert Doppenberg), me being there to push all to the limits of the very very best.
The new forum board is here because Phasure officially represents the speakers. And, it has been - and it will be my share that all is tuned for the very best indeed with underlaying design features allowing for just that (I am sure I drove Bert crazy).
This post is just introductionary to so much more to come.

What you see below is many days of "tuning" work on the low frequency output of the new Orelo MKII speakers (3x 15"), hereby introduced to you.

Orelo MKII assumes a playing level of 88dBSPL to sustain distortion free in the sub-low region with the notice that 86dB already really is loud enough for me and my room of 12x8x3m / 36x24x9ft; halve the size of the room and expect ~6dB less output to sound as loud.

Distortion free means : No audible harmonics, and that requires the THD (Total Harmonic Distortion) to be better than 3.8% in the range under 100Hz.
Audible harmonics : For example a 20Hz tone which is totally inaudible to us humans, but now showing a profound audible 40Hz tone because of a 2nd harmonic (40Hz) being too high (worse than 3.8% THD).

This is the Orelo MKII, super-straight up to 19Hz (less than 0.5dB "ripple").

The roll-off slope you see never shows audible THD anywhere on that "line". So for example, where the line crosses the 55dB point (which is at around -12.5dB related to the output signal level) THD will still be under 3.8% and the 17Hz which is in order there will still be just that (and will not become an audible 34Hz because of too much distortion on the 2nd harmonic or 51Hz because of a third harmonic etc.).

We can also say that 18Hz plays at -2.5dB (look where the line crosses the -65dB point). Or 17.6Hz or so when the very common spec "at +/- 3dB" would be used.
Thus, when this would be a normal speaker with commonly accepted specs it would be rated "straight to 17.6dB +/-3dB".

However, 3dB is quite a lot, and especially in the sub low frequency range this matters. And thus I make it :

Straight to 19Hz - period.
Playing levels of 88dBSPL assumed.

Of course playing louder is possible and nothing will break, but now under around 21Hz harmonics will become audible and while you might not even notice it, won't be reality.
The tuning has been done such that all the way down to the 9Hz you see, the distortion will be the same (as low) over the whole frequency range of 21Hz to that 9Hz (and even beyond). On this matter see the small (leftward) bend in the line at the 17Hz point (which is where the line crosses the 55dB point) and notice that under there (16Hz) somewhat more output is given because 16Hz does better on the distortion than 17Hz (than 17-17.6Hz to be exact).
This may come across as too much nit picking, but while the speaker can do what it does, I just tried to squeeze out all of it. And let's say it was worth it after all the super hard work of Bert the past 6 months and I don't want to count out my own either.


Both the Orelino and Orelo MK-II speaker can be auditioned here at Phasure's.
I hope you will be shocked ...

Please ask questions in this forum board when you wonder about something, need customer support etc.
Or when deemed necessary for any reason or for making an appointment for auditioning, send an email to sales - phasure com.

Peter

[manisandher]

Hey Peter, no offense, but is this really the best photo you could take of your Orelo MkII speaker? Satty (my wife) just saw it and immediately said "Darth Vader". Perhaps that was the response you were looking for?

Daa da da daa, daa da daa, daa da daa...

Mani

[rutger21]

Yo P1

So I can finally talk about Orelo MkII properly then?  lol   
Yea more pics more pics please.
Looking forward to this thread developing!
And of course all the juicy details to cum Mr 1
 

P4A(petieboy)

[PeterSt]

Hey Peter, no offense, but is this really the best photo you could take of your Orelo MkII speaker?

Actually yes.

Here you see a picture which is OK for the left half, the right half already making you wonder what you see. Left is matte, right is piano black with the notion this piano black is the nose only (you will see later).

[PeterSt]

A detail like this looks rather nice :

but here you see how things can get difficult :

Really not fotogenic ...

But beautiful !

[Nick]

Peter hi,

Im doing some work on room matching my Orelos IIs, I'm very pleased with results so far. I have always had significant bloom in bass due, I think, to rear wall / corner interactions. I have appiled some simple DSP adjustments that have vastly improved bass reproduction. I will post the method used in case it is of used to anyone else when I'm satisfied with the results.

Doing this has raised a question if you could help.

When you generated the bass response curve for the Orelo IIs, that you put up in the graph in the first post in this thread, were use using your NOS1 and audio PC to generate the sweep signal that was sent to the speakers or did you use another device such as your DScope to create the sweep input to the speakers ?

The reason I ask is that with my current setup I am getting some significant driver excursions at  20 to 30 hz when I am playing sweep files through my NOS and when playing a few tracks with very low bass effects dubbed into the track. Im trying to work out where to focus attention to deal with this and it would help to understand how the the origional calibration took place.

Thanks and regards,
Nick.

[PeterSt]

When you generated the bass response curve for the Orelo IIs, that you put up in the graph in the first post in this thread, were use using your NOS1 and audio PC to generate the sweep signal that was sent to the speakers or did you use another device such as your DScope to create the sweep input to the speakers ?

Hi Nick - Question of the year !

The answer is, No, it is not allowed to use the NOS1 for this. This is because you wouldn't be using XXHighEnd to play the signal (well, you could, but using e.g. REW would be more logical and intuitive) ... and then the reconstruction filtering would lack, which the NOS1 requires (well, in my own thinking of course and I suppose every NOS1 owner happily agrees).
I fell in that pitfall myself after noticing the relatively heavy roll off of the highs. Never looked at the bass because I didn't get round to that. I just started using the output of my ADC (which is also a DAC).

What you could have observed is the relative more pronounced signal, the lower the frequency. Thus, the roll off with "genuine NOS" is there right from the start (lower frequency), increasing more and more towards the highs. Thus any swept signal would be loudest in the bass ...

Best regards,
Peter

PS: You might also want to consider the pandora's box when you realize that playing through XXHighEnd and its diverse settings and various Operating Systems for that matter, will let (physically !) feel the woofers different in each situation. Take distance of that or you will get mad. Thus, this signal generator you will be using (like from REW or hardware etc. etc.) WILL express only one of these 100s of situations only, and you can not change that. It will never represent your playback reality ...

[Nick]

Peter hi,

Thanks, for all the very useful information.

I assumed that you would not have used the NOS and XX as the calibration signal source for some of the reasons you gave but just needed to double check. But very good to get it confirmed so I can cast my attention back towards my room and pc setups and trust the DSP curve.

In another answer where I spoke about relativly large bass cone deflections you mentioned that these large excursions generate second harmonics. In the real time FFTs of low frequency sweeps Iv been looking at, and just as you said, when cone excursjons are large those second harmonics are present ! This is not too much of a concern whilst listening though as the bass sound quality is still superb.

On a happy note, its very difficult to overstate the transformation in bass sound quality that the dsp tweeks to compensate for rear wall and corner reinforcements have made. So as not to go off topic in this thread I will start a new thread on the tweeks, it just may help other owners.

Regards,
Nick.

[PeterSt]

Hi again Nick,

In the real time FFTs of low frequency sweeps Iv been looking at, and just as you said, when cone excursjons are large those second harmonics are present !

Yes, but it is to keep in mind that calibration takes place (has taken place) under the strict condition of 89dBSPL (no more but also no less in order not to fool ourselves). And *then* the excursion is within range in such fashion that no audible distortion occurs (and excursion is maybe 0.5cm (but I forgot)). Thus, 20Hz remains that (no 40Hz audible). 19Hz remains that. 18 ... all the way down. This is all arranged for in the DSP (per my preset of course). It could be a good idea not to mangle there and take very good care of understanding the principles first (which is exactly whay you asked of course !).

Kind regards,
Peter

[vrao]

Oops ... didn't read the dates of the thread 

[PeterSt]

Oops ... didn't read the dates of the thread 

So what's up ?
All seems fine to me.