According to the equal loudness contours, a ~10dB difference <40Hz sounds like a 20dB difference, so I would say that’s too much. I usually see -6dB, which seems good as speakers use a 6dB deviation window (+/-3dB) as well.
Subwoofer low frequency extension:
What's a useful spec for the usable frequency range?
-3dB?
-6dB?
-10db?
None of those numbers are useful. The only meaningful specification for a subwoofer/bass-system is spl output capacity in the frequency range it is meant to reproduce. Frequency response in itself does not matter.
I have repeatedly explained why and how and what, even wrote an article on this specific subject, I do believe I have posted links to that article also on this forum. For someone with a technical background, this is not very difficult to understand.
Can you link me?
+/-3dB rating on this baby ...
• https://www.paradigm.com/en/sealed/seismic-110
SPL output capability, not many manufacturers mention that spec.
...And for each frequency covering the low three octaves.
Best is to measure them in our own rooms.
* Kvalsvoll, you have a link please to your article on this specific subject?
There are ... total number of posts, and ... total number of threads here @ ASR.
If we were to read them all it would take ... number of months (perhaps years).
I sincerely hope my previous reply was not taken as criticism for asking the question, nor discussing the matter. Any question must be welcomed and replied to in due respect, it is just that sometimes, well, you get the idea..
I found the article: https://www.kvalsvoll.com/blog/2018/02/25/specification-for-subwoofers/ (It is on my web-site, but it does not promote any of my products or tech solutions, as far as I can remember.)
And now I am going to read it myself. Because this was written 2 years ago.
None of those numbers are useful. The only meaningful specification for a subwoofer/bass-system is spl output capacity in the frequency range it is meant to reproduce. Frequency response in itself does not matter.
I have repeatedly explained why and how and what, even wrote an article on this specific subject, I do believe I have posted links to that article also on this forum. For someone with a technical background, this is not very difficult to understand.
I would have a hard time finding those posts myself.
+/-dB window doesn’t matter much, but how deep the response digs does matter, and at what SPL.None of those numbers are useful. The only meaningful specification for a subwoofer/bass-system is spl output capacity in the frequency range it is meant to reproduce. Frequency response in itself does not matter.
I have repeatedly explained why and how and what, even wrote an article on this specific subject, I do believe I have posted links to that article also on this forum. For someone with a technical background, this is not very difficult to understand.
I think the original question is 'at what frequency does the output of a subwoofer no longer contribute meaningful information?' At least that's how I read it. As I said, there is no standard for this that I am aware of. I don't interpret the question as asking what makes a good subwoofer, just a query regarding the point at which any output is no longer meaningful.
I think the original question is 'at what frequency does the output of a subwoofer no longer contribute meaningful information?' At least that's how I read it. As I said, there is no standard for this that I am aware of. I don't interpret the question as asking what makes a good subwoofer, just a query regarding the point at which any output is no longer meaningful.
+/-dB window doesn’t matter much, but how deep the response digs does matter, and at what SPL.
Amir has asked how he should measure subs, as a 2.83V Spinorama is not very useful. My vote was for CEA-2010 at minimum, with the addition of group delay (which should give the same info as a waterfall and spectrogram) being highly requested. Data-bass remains the best website for subwoofer measurements, and I know Amir is not willing to put in the work to be as extensive. Another issue is Amir being able to do a CEA-2010 test without disturbing his family, but more importantly, not pissing off neighbors.
The Dayton sub-1200 and BIC F12 are the most popular decent subs. Polk makes the most popular budget subs.A simpler test may still be useful, as long as it shows capacity, perhaps distortion. A simple compression sweep set could do the job.
It also makes sense to test smaller subwoofers. Because that is what many actually buys, and not everyone needs demolition-spl.