KEF Unicore

[bo_knows]

Well the sub make a big difference there, i hear a little more the sub in the left side of my speakers xD
10:47, after a little i hear the subs notes in both speakers, maybe its the song i dont know im a little confusing xD

I'm using my laptop and Sennheiser HD660.

 

[BrokenEnglishGuy]

I'm using my laptop and Sennheiser HD660.

do you find the bass in 10 47 are fine in both channel ?
forget it, i just have a one speakers a bit more far than the other

 

[raistlin65]

Why listening to YouTube video demos for speakers (and subs) is a bad idea

 

[Bear123]

I can see the point, somewhat, of actually being able to hear the difference in bass extension between tiny bookshelf speakers vs pairing them with a sub. But yeah, listening to recordings of speakers on you tube on your speakers or headphones, and imagining it sounds anything remotely like the actual speakers.....I don't understand how anyone could think that. A few guys on AVS speaker forums are always gung ho about suggesting people listen to speakers on Crutchfields speaker comparison tool over headphones........one poster did so and was like.....ummm....I couldn't really tell the difference between a Revel Salon 2 and a Dayton speaker. Said his wife couldn't really tell the difference either......what a joke to think you can tell how speakers sound in such a way.

 

[napilopez]

For a comparison, here is how that would stack up against a few different options ranging from large ported to small sealed:
1) Rythmik FV15HP 6.5ft^3 ported 15" $1400
2)Rythmik F18 sealed 18" 5.6ft^3 $1670
3)JL Audio E110 sealed 10" 1.8ft^3 $1650
4) SVS SB12-NSD 12" 1.8ft^3 $599(probably *about* the same as any of their current smallest sealed subs i.e. SB1000,2000)

View attachment 107989
If the KEF does 80 dB at 20 Hz, that puts it one line up from the bottom on this comparison graph, for perspective. For me, it would be REALLY hard to justify that over the much cheaper SVS, or the JL Audio for similar price to the KEF but higher performing than the SVS. Both of those subs are pretty diminutive in size, IMO.

I thought the first three were an interesting comparison because it shows you what similar money gets you from large ported, large sealed, and small sealed. And last, what inexpensive small sealed gets you. Tiny sealed, one has to visualize based on 80 dB at 20 Hz. 10 Hz from the KEF would be completely imperceptible unless wearing as headphones.

Here's my attempt at estimating the KEF. I don't claim a high level of accuracy as the CEA2010 numbers posted for the four subs are 2m RMS which are 9 dB lower than 1m peak figures which are commonly used. So I think where I placed the KEF trace is probably a very generous absolute best case scenario in terms of comparison:
View attachment 107991

These estimates seem likely to track right! 92dB at 30Hz is the number I got from KEF. Of course this says nothing of distortion and other parameters, but still, clearly nothing crazy is happening in terms of max output. The good news is that I expect I'll be able to get my hands on a KC62 soon, so I'll be running what tests I can!

Assuming the results track, we return to the question of whether that is enough bass for the size and price. It's a topic worthy of its own thread, really: How much bass is enough for what purposes. I feel like there's a lot of confusion over loudness curves and peak loudness requirements (some of it my own!).

Of course, the proof's in the pudding and all that, so we'll see. Might as well compare it to the SB-1000 in both objective and audible metrics while I'm at it too.

 

[sweetchaos]

The good news is that I expect I'll be able to get my hands on a KC62 soon, so I'll be running what tests I can!

Excellent news!

 

[napilopez]

Excellent news!

Yeah, might be a while before I can get something useful out of the measurements though. Gotta find somewhere I can do ground plane measurements in the city as I expect the Umik-1 will start clipping at the SPLs I'd need to test... Still, will be interesting to start with in-room measurements at different SPLs.

 

[sweetchaos]

Yeah, might be a while before I can get something useful out of the measurements though. Gotta find somewhere I can do ground plane measurements in the city as I expect the Umik-1 will start clipping at the SPLs I'd need to test... Still, will be interesting to start with in-room measurements at different SPLs.

When you're done, can you send to Erin for full CEA2010A/B testing?

J/K, we'll take any measurements over Kef's marketing talk anyday.

 

[pjug]

Yeah, might be a while before I can get something useful out of the measurements though. Gotta find somewhere I can do ground plane measurements in the city as I expect the Umik-1 will start clipping at the SPLs I'd need to test... Still, will be interesting to start with in-room measurements at different SPLs.

You can open the Umik-1 and lower the amplifier gain. I guess there will be a limit where the microphone element saturates too; I have no idea what that is. Some photos here: https://www.avsforum.com/threads/massively-clipped-umik-1.1797489/

 

[napilopez]

You can open the Umik-1 and lower the amplifier gain. I guess there will be a limit where the microphone element saturates too; I have no idea what that is. Some photos here: https://www.avsforum.com/threads/massively-clipped-umik-1.1797489/

well well, you learn a new thing every day! I still think i'll try to find somewhere for ground plane as I've been meaning to compare ground plane and nearfield measurements for some time, but this is great to know!

 

[whazzup]

Yeah, might be a while before I can get something useful out of the measurements though. Gotta find somewhere I can do ground plane measurements in the city as I expect the Umik-1 will start clipping at the SPLs I'd need to test... Still, will be interesting to start with in-room measurements at different SPLs.

Isn't the umik-1 rated to go down to 20hz only? Or I thought wrong?

 

[napilopez]

Isn't the umik-1 rated to go down to 20hz only? Or I thought wrong?

I have a CSL-calibrated Umik-1, which is calibrated down to 5 Hz

 

[whazzup]

I have a CSL-calibrated Umik-1, which is calibrated down to 5 Hz

Aw man, can't wait for you to get the KC62. How long do I need to hold my breath for?

 

[Kachda]

Yeah, might be a while before I can get something useful out of the measurements though. Gotta find somewhere I can do ground plane measurements in the city as I expect the Umik-1 will start clipping at the SPLs I'd need to test... Still, will be interesting to start with in-room measurements at different SPLs.

If I still had my house in the 'burbs, I would have offered you my backyard to do the testing...for purely unselfish purposes of course

 

[Senior NEET Engineer]

92 dB at 30hz... even a Sonos Sub can do 99+ with higher WAF form factor

 

[Juhazi]

UMIK-1 has 1% distortion at 133dB https://www.minidsp.com/images/documents/Product Brief - Umik.pdf
it's rated 20Hz up, but performs consistently even lower

 

[killdozzer]

Since it's a BS product, naturally you can't find any spec on the said 11Hz (even after waiting awhile, and I did). But taking what was apparently confirmed; 20Hz at useless 80dB:

And we see the membrane should travel almost 4cm (3.83) - ONE WAY!!!! What exactly are we hoping to measure? What do you think is the unknown here?

And in the video of the little driver dying in front of our eyes it doesn't do 4cm and it is already visible by naked eye it is not pistonic.

This is a huuuge portion of reputation of once respected number-based company down the toilet only to be able to charge 60% more then they should for a dumb lifestyle toy. Ah, yes; but it's tiny, and that somehow makes it alright, I forgot about that.

All the while; they might've said; "this little thing will do a usable and audible slightly below 30Hz in a room up to max 30 square meters and it would still deserve a gold medal.

 

[napilopez]

Since it's a BS product, naturally you can't find any spec on the said 11Hz (even after waiting awhile, and I did). But taking what was apparently confirmed; 20Hz at useless 80dB:

View attachment 108723
And we see the membrane should travel almost 4cm (3.83) - ONE WAY!!!! What exactly are we hoping to measure? What do you think is the unknown here?

And in the video of the little driver dying in front of our eyes it doesn't do 4cm and it is already visible by naked eye it is not pistonic.

This is a huuuge portion of reputation of once respected number-based company down the toilet only to be able to charge 60% more then they should for a dumb lifestyle toy. Ah, yes; but it's tiny, and that somehow makes it alright, I forgot about that.

All the while; they might've said; "this little thing will do a usable and audible slightly below 30Hz in a room up to max 30 square meters and it would still deserve a gold medal.

Just a small note: a 6.5-inch woofer typically has a pistonic diameter of about 5 inches, though im not sure if the calculator takes that into account. A smaller diameter of course increases the xmax further, about 5mm rather than 4.

Edit: just reread your post. The xmax value is in millimeters not centimeters. Also, the wobbling you see in the video is due to the camera's rolling shutter not the woofer.

 

[voodooless]

And we see the membrane should travel almost 4cm (3.83) - ONE WAY!!!!

I don't want to be a party pooper, but it says mm, not cm.. I'm guessing the those KEF woofer will have at least 12mm one way, probably a bit more. I suspect it can do about 90~93 dB at 20Hz. The 80dB at 11 Hz would also fit the 12mm one way. It pretty much tracks https://www.audiosciencereview.com/forum/index.php?threads/kef-unicore.19376/post-647560

 

[BDWoody]

Since it's a BS product

You've made your point over and over.
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