new KEF KC62 dual 6.5" subwoofer

[waynel]

So it's bigger and has no DSP? Yeah, that's the same.

I think the problem here is people trying to single out one feature and then find another sub.

But it's the combination. As small, as low and with the DSP (and the build). I doubt it would come any cheaper from any of the companies you're mentioning.

yes , the kef is tiny and usable to ~30Hz at low volume , but if one has just a little more space the SVS SB 1000 pro is better in every way.

Here is a size comparison with the svs in green and the kef in red, while the svs looks much bigger, it’s still tiny

 

[KMO]

Not immediately obvious why you'd compare the SB 1000 Pro to the KEF KC62. They're different size classes.

The KEF KF92 is the comparable model by dimensions. (Same width, 0.5" less deep, 0.4" taller).

I agree that most people could fit a KF92/SB 1000 Pro-sized sub - they're pretty compact - and shouldn't have to go down to KC62. I have a KF92 myself, and had no reason to take the KC62.

 

[waynel]

Not immediately obvious why you'd compare the SB 1000 Pro to the KEF KC62. They're different size classes.

The KEF KF92 is the comparable model by dimensions. (Same width, 0.5" less deep, 0.4" taller).

I agree that most people could fit a KF92/SB 1000 Pro-sized, and shouldn't have to go down to KC62. I have a KF92 myself, and had no reason to take the KC62.

Because it’s the smallest halfway decent(at low volumes and/or nearfield) sub that I could find. Any smaller leads to big compromises.

 

[killdozzer]

yes , the kef is tiny and usable to ~30Hz at low volume , but if one has just a little more space the SVS SB 1000 pro is better in every way.

Here is a size comparison with the svs in green and the kef in red, while the svs looks much bigger, it’s still tiny

So, just as I said. Not quite as small, which is in relation to how low it can go, not quite the build quality and not quite the DSP. At least I hope you're not trying to say that if KEF opted for a bigger size, it still couldn't go lower? Of course you're not, which implies that SVS wouldn't go as low if it was made as small. And perhaps SVS couldn't even make it as small if KEF patented the coil within coil (development of which would affect the price in itself).

See what I'm getting at? if it's the mix of features that make it what it is, you can't really say well if it's a bit bigger it could go lower, since no one doubted this in the first place.

Or to put it another way, if SVS was to be proven better, it would have to match all the restrictions and achieve all the results.

And that red/green image says to me; double the size. This could even portray SVS as playing "poor for the size".

 

[killdozzer]

My biggest objection to kc was the 11Hz claim. If the message was it can do usable 20Hz, it wold still be very impressive. This was it just comes off as dishonest. IMO, that was a mistake.

 

[Deleted member 48726]

Hang them from the ceiling.

Yeah but then you get a lot of crying noise I suspect. And in due time you will have the authorities knocking on your door..

 

[waynel]

And that red/green image says to me; double the size. This could even portray SVS as playing "poor for the size".

11dB at 20 Hz is 3.5 times the output.

here is a plot I made a few years ago using all the small and medium sided subs on data-bass. If I have time I’ll repeat it with the sweet chaos subwoofer comparison data. At the time JL were the highest output at 20 Hz for the size. I don’t think the kef would be above this trend line.

Also here is the plot for all the commercial subs on data-bass Including the large ones. For bigger subs, JTRs did particularly well in output for a given size.

 

[3125b]

I don’t think the kef would be above this trend line.

At about 0.55 cubic feet (what a terrible unit of measurement) and 80dB SPL capability it would not. It's not too bad however, only 1dB less output than that REL down there that's four times the size.
Updating that graph would not be a bad idea though, more modern DSP subs way outdo everything in there.

 

[kemmler3D]

Just set up my 2x KC62s and the subjective impression is honestly quite good. I have neighbors on each wall so I'm not going to be playing even moderately loud very often, and my room is only about 20 x 20 x 10 feet. They do what I want them to do - cleanly fill in nulls and help the LS60s maintain an authoritative sound full-range.

We're talking 12 ~6.5" drivers handling bass in this room (with pretty high excursion) and so I think it actually does really well. The KC62s are more to even things out than carry the team in this setup, but it works well.

Just as importantly, they are unobtrusive in the room and easy to set up with wireless transmitters. Again, poor value for dollar if you want max. output... the primary design target was obviously size, not SPL. IMO a great option if you have strict decor requirements (you can really just shove one behind an armchair or under a side table or something) and you still want a relevant amount of output below 30hz and you manage to get a killer deal on them.

 

[killdozzer]

11dB at 20 Hz is 3.5 times the output.

There it is again. Apples to pears. I really don't understand why is this simple concept so difficult for you to grasp. I'll start thinking you're just trolling.

Here it is once more:
kc62 = 0.55 cubic feet / 15,625 cubic cm
sb 1000 pro = 1.4 cubic feet / 39,830 cubic cm

It is even more than double the volume as I first said judging by the image alone. It is so funny how in my comment number 538 I said people keep neglecting certain aspects and keep comparing kc62 out of its class only to have you keep neglecting certain aspects and keep comparing it out of its class.

In order to be able to compare the performance of a half a cubic foot sub, you need another half a cubic foot sub. Not foot and a half, not foot, not three feet. It has to be half a cubic foot.

Hope this helps.

 

[sifi36]

11dB at 20 Hz is 3.5 times the output.

here is a plot I made a few years ago using all the small and medium sided subs on data-bass. If I have time I’ll repeat it with the sweet chaos subwoofer comparison data. At the time JL were the highest output at 20 Hz for the size. I don’t think the kef would be above this trend line.
View attachment 314391
Also here is the plot for all the commercial subs on data-bass Including the large ones. For bigger subs, JTRs did particularly well in output for a given size.
View attachment 314392

I had a quick and dirty play with sweetchaos’ sheet and it appears to me that the relationship between volume and spl at 20Hz is possibly logarithmic or quadratic (the difference in r-squared isn’t massive though), which makes sense to me as at 0cuft you would get 0dB. On that basis, the KC62 would be slightly above the line.

 

[VintageFlanker]

I guess the KF92 should be a lot better,

The review is now on YT.

 

[waynel]

The review is now on YT.

I'm not too impressed. The SVS SB-1000 pro is a much better sub for less than 1/3rd the price and is the same size. It's 5dB better at 20Hz and even better from 25Hz-100Hz

 

[waynel]

I had a quick and dirty play with sweetchaos’ sheet and it appears to me that the relationship between volume and spl at 20Hz is possibly logarithmic or quadratic (the difference in r-squared isn’t massive though), which makes sense to me as at 0cuft you would get 0dB. On that basis, the KC62 would be slightly above the line.

View attachment 314505
View attachment 314504
View attachment 314507

Thank you for for doing this! I think the linear fit is appropriate as the dB scale is already a log scale. Also, If you look at similar lines of subs such as sealed boxes from the same manufacturer or ported boxes from the same manufacturer, linear fits very well.

 

[VintageFlanker]

I'm not too impressed. The SVS SB-1000 pro is a much better sub for less than 1/3rd the price and is the same size. It's 5dB better at 20Hz and even better from 25Hz-100Hz

Told you...

He already shared the KF92 CEA-2010-A data on his Patreon. IMHO, it is clearly not impressive at that price point.

 

[3125b]

Underwhelming for a medium sized sub with two 9" drivers (should have slightly more area than 1 12"). And the SB-1000 Pro is smaller.
The efficiency/sensitivity of this design must be terrible, not sure how they managed that. Three times the power should give it a 5dB advantage given the same effciency.

 

[bodhi]

About what I expected. For me this confirms that the room matters a lot: I compared the KF92 with Arendal 1S in my room and there just wasn't a difference even playing at volume far greater than I could normally use. And the Arendal seems to be almost 15+ dB across the frequency ranges.

Who knows, I might ask the store if I could get a good deal exchanging the Kef for something stupidly too powerful. Just for fun.

 

[BrokenEnglishGuy]

Well, that also fit with the in room measurements shared from kf92/kc62
You at least won 20dB from 20hz
So its 100dB 20hz+

Now my question is, there is more measurements? What about at THD and resonances?

 

[kemmler3D]

Anecdote here, but the extension these things provide (at least at lower SPL) is real and beneficial. I checked with my go-to sub-bass check song, which opens with a swept tone down to 16hz and back up. I guess it's more of a test tone that happens to be on Spotify. Anyway, the KC62s passed the test. Most systems do not pass this test. YMMV.

Nobody is suggesting these are going to beat larger, traditional subs. I think the point of these is that if you can only fit very small boxes in your living room, for whatever reason, you still have a path to full range at moderate levels.

If you can fit bigger boxes, there are certainly cheaper ways to go about it and go louder at the same time.

 

[sifi36]

So I've had another go at the chart comparison. I had a better look at the data (thank you for compiling and maintaining the sheet @sweetchaos) this time and removed:

• In-walls (as volume comparisons become tricky)
• Anything over 0.4m^3 in size (as there are few measured options and their performance relative to size is all over the place.)

This yields the below chart:

I tried a linear model but the r-squared was significantly lower than with a logarithmic one. One could make the argument that mixing sealed and ported subwoofers, plus ones with single vs multiple drivers muddles the comparison, though if the goal is to rate a subwoofer relative to it's size then I don't think it matters so much.

I then calculated each subwoofer's variance from the model, the pdf file attached lists each subwoofer in order of how much output they have more or less than the model would indicate. I am not a data scientist, so will happily take feedback on my approach, it's probably terrible. The KC62 lands at around 4.4dB more than the model would indicate, the KF92 4.3dB less.