How flat is flat?

[daftcombo]

DSP active speakers of even the smallest variety hit 50Hz flat. iLoudMM being the smallest, but there is also Vanatoo Transparent Zero as well as larger options like the JBL LSR305. The port tuning on a speaker may need to be adjusted in some cases, but if you put a sharp cut (48db/octave or more) after 50Hz you can get just about any speaker to play flat to 50Hz with a good amount of headroom left.

If a speaker can't do the job of playing to 50Hz flat at the volume that I need, then it's not really a complete speaker IMO.

Without correction, the 305p mk2 is not really flat down to 50 Hz, since output is already -3dB.

same thing for the Neumann KH80, with -6dB:

not to speak about passive speakers like the Aria 906:

or even all the Revel 2-way that were measureed here, like the M105:

By the way, with a sharp cut at say 45 Hz, a lot of what is in electronic music goes away.

 

[NoAudiophile]

All of the active examples you offered can be corrected with 6dB or less of EQ to get the to 50Hz flat. 12dB or less for passive speakers.

Here is the smallest powered speaker I've tested that does it out the box.
http://noaudiophile.com/IK_Multimedia_iLoudMM/

It is possible, and it is bare minimum for me to accept a speaker as tonally neutral.

As for parts missing under 50Hz, that is true, but not as common as you would think. Try adding a filter to your current speakers to cut below 50Hz, it's only a handful of songs that I can think of off hand that would be obviously affected. On the other hand, starting rolling off at 80Hz makes the whole speaker sound thin regardless of the rest of the extension.

 

[daftcombo]

All of the active examples you offered can be corrected with 6dB or less of EQ to get the to 50Hz flat. 12dB or less for passive speakers.

Here is the smallest powered speaker I've tested that does it out the box.
http://noaudiophile.com/IK_Multimedia_iLoudMM/

It is possible, and it is bare minimum for me to accept a speaker as tonally neutral.

As for parts missing under 50Hz, that is true, but not as common as you would think. Try adding a filter to your current speakers to cut below 50Hz, it's only a handful of songs that I can think of off hand that would be obviously affected. On the other hand, starting rolling off at 80Hz makes the whole speaker sound thin regardless of the rest of the extension.

Ok let's try this correction for Aria 906 today:

 

[daftcombo]

Hmm... not a success for the moment. It started well, for the right speaker (the left being in the corner produced insane bass congestion) with deeper notes.

But, that right speaker playing alone now struggles to deliver the bass lines of Donny Benét, even at moderate volume:

It is one of my personal test tracks so...

 

[daftcombo]

I re-measured one of the Aria 906 at 10 cm (4 inch) from midway between the woofer & the port. Then corrected to flat down to 50 Hz. I ended with something in RePhase very similar to what I posted before, just less sharp.

I also measured the distortion at moderate volumes and there is nothing bad about it.

It now goes deeper and there is a very positive effect: what I thought was a room mode at 110 Hz is now very less audible. That room mode was also the exact climax of the FR, whereas it is now just a point on a rather flat line between 50 hz and 20 000 Hz. So it seems like a slope just before a room mode makes it more audible (and annoying). Interesting.

 

[dasdoing]

It will not only depend on Q but also on the frequency. you can do one funny exercise to find out how strong magnitude changes are. use a DAW or Audacity. import a song two times. invert polarity of one. every eq you throw on now will be isolated

 

[Rja4000]

I guess answer is the same than with SINAD:
We don't know for sure that 120dB SINAD is required.
Probably not.
But, for sure, you can't hear distortion and noise at that level.

Same applies for EQ: Use 0.1dB and you're safe.
At least for electronics.

For loudspeakers, well, it doesn't make much sense, since moving in the room will have more impact than that, anyway.