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new KEF KC62 dual 6.5" subwoofer

stren

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Is this data written up anywhere or only presented in the video?
 

phoenixdogfan

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By way of comparison, the all time best seller of SVS, the OG SB 2000 with its 12" woofer capable of playing 100 db at 20 hz has been selling at their outlet store for $500. It's possible to buy three of those for the price of a single KC 62, of course you would need your own dsp, but it has a high/low pass built in.
 

waynel

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By way of comparison, the all time best seller of SVS, the OG SB 2000 with its 12" woofer capable of playing 100 db at 20 hz has been selling at their outlet store for $500. It's possible to buy three of those for the price of a single KC 62, of course you would need your own dsp, but it has a high/low pass built in.
From the Sweetchaos sub comparison spreadsheet the SB 2000 measured by Brent Butterworth achieved 95.1dB at 20Hz so 15dB better than the Kef.

 

kemmler3D

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Definitely not the sub you'd get for maximum output, but if you have strict design requirements for your living room, it can be the best option. There is a lot to be said for a small, nice-looking, wireless sub that doesn't get any objections, vs. a large, powerful sub that ends in divorce.

I got a steal of a deal on 2 of them and they should be here tomorrow, I will post impressions / measurements not too long after.
 

Ron Texas

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I'm skeptical that a pair of 6.5" drivers could go very low no matter how many engineering tricks were used.
 

Vacceo

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I'm skeptical that a pair of 6.5" drivers could go very low no matter how many engineering tricks were used.
They do. Not loudly, but they do.

That said, KEF should update their line of subwoofers with something more conventional in 10 or 12 inch drivers.
 

waynel

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I'm skeptical that a pair of 6.5" drivers could go very low no matter how many engineering tricks were used.
They do. Not loudly, but they do.

That said, KEF should update their line of subwoofers with something more conventional in 10 or 12 inch drivers.
Not loudly enough to matter at 20Hz. 80dB at 20Hz sounds like 5dB SPL at 1kHz
 

YSC

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Not loudly enough to matter at 20Hz. 80dB at 20Hz sounds like 5dB SPL at 1kHz
Well it’s body shake that feels 20hz, and practically at least with room gain I bet it could do like 85db at 20hz.

This is strictly for really tiny room where typical “small sub” measuring ~35cm square footprint don’t fit especially in Asian space (see Japan and Hong Kong prison cell sized rooms and apartments). Say in my personal room, I have to put any sub under desk, and preferably with a high pass, anything past like 25cm in depth will seriously interfere with my leg room so back then the options are this, genelec 7040 and the opposite dual woofer dynaudio sub 18.
End up considering price and slimness I chose the 7040, which in room does like 30hz lowest, provide me with enough low bass without neighbours coming in to discuss about his issues, this kc 62 if cheaper, would do even better with similar footprint
 

KMO

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By way of comparison, the all time best seller of SVS, the OG SB 2000 with its 12" woofer capable of playing 100 db at 20 hz has been selling at their outlet store for $500. It's possible to buy three of those for the price of a single KC 62, of course you would need your own dsp, but it has a high/low pass built in.
You could, but they wouldn't work so well after being installed into the same space as the KC62. You'd have to crush them down quite tight!

You're paying for retained functionality after size reduction.
 

stren

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They do. Not loudly, but they do.

That said, KEF should update their line of subwoofers with something more conventional in 10 or 12 inch drivers.
"should" - KEF's marketing strategy has always been to be a little different to most audio companies and to focus on products that perform well within a small footprint/package. Realistically they have more of a lifestyle bend to their products. There are plenty of 10/12 inch sub products from other companies - what would they really be adding? The KC62 was a different product that adds unique capabilities not found anywhere else. At most I can see them extending the unicore sub tech to a larger model and making a smaller "big" sub, but I can't imagine them ever doing a sub that would hit 20Hz at decent output in large rooms. I'd rather them continue to innovate with products like the LS60 and improve longterm reliability rather than doing a "me too" sub.
 

kemmler3D

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I'm skeptical that a pair of 6.5" drivers could go very low no matter how many engineering tricks were used.
It's all a matter of volume "enclosed" by the range of motion of the drivers. I think they've really pushed the reasonable limits of xmax on these with the folding surrounds and concentric voice coils. I guess the dual opposed design also allows high excursion without unwanted vibrations. And then apparently they have a motion feedback system to reduce distortion, which probably allows them to push excursion a bit more without excessive distortion.

So, I mean, no, a 6.5" is not going to equal the displacement of 15" or even 11" with any kind of sane design. But, I have some optimism that they've pushed the envelope with LF extension and small woofers noticeably.

You're paying for retained functionality after size reduction.

A good way to put it. If I had more space and no constraints on aesthetics, the KC62 would be a bad choice. It's expensive and doesn't put out a lot of SPL for the money. If you're in a situation where ANY sub is already a hard sell, then it starts to look like the only choice. Wireless (with the kit), tiny, and has real LF extension, albeit at unimpressive SPL? Well, it beats the hell out of nothing. A dealer basically threw two of them in with the LS60s so why not?
 
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Puddingbuks

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Just for reference and getting a feeling of numbers and spl differences, here is the KC62 compared to a monoprice monolith 15, which is about the same price but about 10-15x the size.

It’s 29db difference @20hz and 24db @40hz.
 

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kemmler3D

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Just for reference and getting a feeling of numbers and spl differences, here is the KC62 compared to a monoprice monolith 15, which is slightly more expensive but about 10-15x the size.

It’s 29db difference @20hz and 24db @40hz.
Oof. No replacement for displacement, as they say. On the other hand, >90dB at most frequencies would be a fast way to make enemies with my neighbors. In my current place I would like to avoid that... so there's not much call for a bigger sub anyway.
 

3125b

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Looking at the 16" Monolith that's a whopping 38dB SPL capability @20Hz over the KEF, meaning it would take 80 of the KEF subs to reach the output of one 16" Monolith that is "only" 16.7 times the size and 2 times the price of the KEF.
 

stren

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That is pretty hilarious 16" = 6*6.5" by area of the driver - so you'd think it would be 3 KC62 to equal it- but I guess the xmax of the 16 would be more? Even still big difference of 80 vs 3 lol.
 

BrokenEnglishGuy

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Looking at the 16" Monolith that's a whopping 38dB SPL capability @20Hz over the KEF, meaning it would take 80 of the KEF subs to reach the output of one 16" Monolith that is "only" 16.7 times the size and 2 times the price of the KEF.
As far as i know it's 3dB per sub/speaker added.

20Hz -> 80dB -> x2 Subs -> 83dB.
38/3=>12.6 KC62.
Edit: Fixed numbers
That is pretty hilarious 16" = 6*6.5" by area of the driver - so you'd think it would be 3 KC62 to equal it- but I guess the xmax of the 16 would be more? Even still big difference of 80 vs 3 lol.
6.5''x2 => 8''
8''x2 => 10''
10''x2=12~''
12''~x2 =>15''
3 KC is not even close to the area to that monolith.
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If double the distance is a decreasse of 6dB, and add a speaker is 3dB. Why i remember it was an inverse? like 6 and 6? or im missing something?
 
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