Interpreting CEA-2010

[alfarn]

Hi,

I have a couple of questions about how to interpret CEA-2010 results when making a purchasing decision on subwoofers.

The budget subwoofer selection in my area is very limited, but I've narrowed my options down to the Jamo C 912 and Polk HTS 10. The plot below shows their CEA-2010 results that I obtained from the subwoofer comparison spreadsheet by @sweetchaos.

Question 1: Assuming the system will be equalized with UMIK-1/REW, can I more or less ignore the stock frequency response of a subwoofer and instead look at its max SPL at low frequencies?

If yes, then based on the CEA-2010 results I would conclude that the Polk is better for 30 Hz and above. So for a target frequency response that is flat down to 30 Hz, then Polk would be the choice. But if the target is flat down to 25 Hz, then the Jamo might be better. Or is this an over-simplification?

I'll be listening to music in a fairly small room, 22.3 m^3 or 785.8 ft^3, with the subwoofer placed 1-2 m (probably corner loaded) from my listening position. Therefore, I assume that the max subwoofer output at my position will be several dBs higher than what is reported in the CEA-2010 test. I haven't measured my typical listening volume, but I would say it's around 60-70 dB (a normal-conversation kind of volume).

Question 2: Would the Jamo's 95.5 dB or even the Polk's 92.7 dB max SPL @ 25 Hz (based on CEA-2010) suffice for my use case, if my target frequency response is to be flat down to 25 Hz?

Again, this might be an over-simplification on my part. I would love to hear some insights. Thanks!

 

[Curvature]

1. Subs work in the modal region of the room. The room is in charge there, not the sub. So as you say the stock frequency response doesn't matter unless there is evidence of resonances or woofer breakup above 100Hz. Usually not an issue since you should be high passing the output.

1.5. The CEA-2010 measurements capture peak burst output, rather than continuous, which will be lower and more representative of listening SPL.

2. You are choosing between small subs. You will not get useful output below 30Hz. 95dB SPL at 25Hz is very quiet (equivalent to about 30dB SPL at 1kHz), and this number describes max instantaneous output here. Better to apply a high pass filter and decrease IMD and reduce strain on the sub. The Polk is unquestionably better than the Jamo.

2.1. If you want useful output at 25Hz or lower, you will need to spend more and get at larger sub. Preferably 15".

2.2. Make sure you have a plan for integration. It is not simple. You'll need a reliable, calibrated measurement microphone and equipment capable of PEQ and/or autoEQ. Work that into your budget if you haven't done so already.

I haven't measured my typical listening volume, but I would say it's around 60-70 dB (a normal-conversation kind of volume).

Think spectrum. 70dB SPL at what frequency? It's a meaningless statement otherwise, as are manufacturer specs which state max SPL as one number without adding the appropriate context.

Without thinking about spectrum vs. level, you likely underestimate your requirements and real use. Speakers and sub sound terrible at max or close to max output. One reason is distortion, and another is compression.

As long as you're realistic about what these small subs can do, go for it.