I am interested in a subwoofer for my KH 80 and am not interested in high volume listening. Some people say: "The KH750's performance is not impressive at all for its price." That may be true but I do not see it being backed up by measurements. I am having a hard time finding comparable measurements that I understand.
The SB-1000 Pro is plenty loud and goes low enough for me.
The group delay for the KH 750 at 30Hz is 16ms. For the SB-2000 Pro it is 39ms. Can I hear that? How about distortion?
Is the quality of the sound of the SB-1000 pro really comparable to the KH 750?
Here are measurements for each sub you mentioned:
All things considered, ignoring cost and features, sub performance should be judged with these priorities:
- Maximum output
- Extension (how low or high it can play)
- Distortion
- ... somewhere very far down, group delay
If you don't want to take my word for it, your best bet is to look at a bunch of measurements to get a sense of what's impressive engineering. Knowing and being comfortable with the numbers will give you a sense of what you can reasonably expect. Look through these reviews, for example:
https://data-bass.com/
For group delay audibility I have attached a paper with some compiled research. From everything I've read, for low frequencies, there is no sense trading lower group delay for worse performance elsewhere.
For (nonlinear) distortion it helps to understand what it is: extra sound by the sub in addition to the signal. The main effect is how subjectively loud the sound will seem, all else being equal. Lower distortion figures will mean comparatively cleaner and less obtrusive playback even at high output. The more distortion is allowed, the louder playback will seem (it's part of what leads to listening fatigue). This is because, again, higher distortion means there is more sound generated by the sub itself along with whatever signal you are feeding it. More energy is being produced than you've asked for, in other words. Distortion is rarely high enough to be perceived separately. That will usually happen only if some part of the signal chain is clipped (likely severely). In terms of audibility there are studies that show thresholds, but those vary a lot by signal and playback level. Like with group delay, more useful to look at what's available on the market. Lower distortion is better, but it's not something to obsess about if your budget is limited.
Judging distortion is somewhat simplified through CEA 2010 measurements, which give the highest SPL figures a sub can output without breaching a defined distortion level per frequency (perceptually based). Unfortunately we don't have CEA 2010 figures for the KH750, but we do have maximum SPL figures. Keep in mind that CEA 2010 measurements are based on transient/burst signals, while other max SPL measurements are long term.
From the measurements, KH750 delivers less output than either SVS model, can't play as low (but does play cleanly much higher) and is significantly more expensive.
So why buy it? The biggest pain with subs is correct setup. The KH750 has a crossover and EQ built in and is designed to work perfectly with other Neumann monitors, including phase and group delay correction. That's reason enough to buy, given how much sweat is needed to integrate subs and mains manually. And then the costs pile up more than they would otherwise if you want to use a multisub KH750 setup often recommended here.
At some point you may decide you need more output. That's the major limiting factor here. I moved to a small apartment and the KH80s were enough for the living room and a 2 meter listening distance. Later moved to a bigger apartment and found them definitely insufficient at 3-5 meters. Since I'm comfortable with measurements and DSP I bought an Arendal Sound sub, which delivers a lot more output than the KH750 and was about 30% cheaper. At some point I'll get bigger active mains, but the sub is a keeper. If I had bought the KH750 I'm sure it would have been fine, but if I ever changed speakers I would lose the main reason for using the KH750, smooth integration with other Neumann speakers, unless I shifted the whole system to a bedroom or something.
