KEF T301C Review (Ultra-thin Speaker)

[GWolfman]

Preference Rating
SCORE: -0.7
SCORE w/ sub: 3.5

A negative score?! Yikes!

 

[Vladimir Filevski]

That could also be marketing misinterpreting what "2.5 way" means.

Measured wide horizontal directivity support 2.5-way claim, single crossover frequency more likely is a marketing blunder.

 

[ThatM1key]

I would like to meet the person that voted "great" on this.

 

[KMO]

As I recall, these are tuned for wall mounting, and they supply (supplied?) stands which have a passive filter to adjust them for free-standing use. (You pass the speaker connection through the stand). Could that explain the bass/treble offset?

 

[respice finem]

That could also be marketing misinterpreting what "2.5 way" means.

Like two-way, half-way usable

 

[Dennis_FL]

I had a similar speaker. The Martin Logan SLM X3 and I ended up selling it for a significant loss months after I got it. The voice dialogues were especially bad. Must be the slim design.

After a move, my high end speakers didn’t fit In the new “open concept “ room. I auditioned quite a few active and passive “slim” center channels and eventually settled on the Sonos Arc. I also now have two separate rooms for music and TV.

 

[vkvedam]

@amirm I still remember the T series home theatre demo they gave at the Manchester Sound & Vision (Circa 2011), it did sound bright to my ears. This particular line from KEF is I am not keen on apart from the looks to impress your better half

 

[anphex]

The directivity balloon looks like a braided yeast bun. So at least there is that

 

[dasdoing]

that's a wife factor dream

I wonder how much sense it makes to meassure the FR/horizontal while vertical on axis, since the user will be always verticly above it

 

[Vladimir Filevski]

I wonder how much sense it makes to meassure the FR/horizontal while vertical on axis, since the user will be always verticly above it

Typical user positions are vertically above center channel loudspeaker and in a wide horizontal arc, so both horizontal and vertical measurements are necessary.

 

[KMO]

That could also be marketing misinterpreting what "2.5 way" means.

Well, no, a 2.5-way design has only one crossover frequency, otherwise it would be 3-way. Rather it's one crossover, and one low-pass-filter.

The huge asymmetry measured here seems to confirm that is indeed 2.5-way, with maybe a 600Hz LPF on the second woofer?

 

[tecnogadget]

I knew from the start the overall response of this speaker would not be perfect because of thin profile and enclosure limitations.

Limited anechoic bass response doesn’t come as a surprise since they are meant to make use of boundary gain by wall mounting.

Still, the low distortion is nothing short of amazing. I was thinking about the little brothers (only one woofer) T101 & T101c, first to try an T101c as a single back surround channel, and if the measured response suits my needs, then replace my surround with T101 and gain space in my room (no speaker stands for surrounds). Of course I would go full FIR correction with this ones, I believe that for surround purposes all those errors (once DSP corrected) won’t be very noticeable (from audibility stand point) vs a regular small bookshelf.

It would be great if we get more In-Room measurements with wall-mount configuration from members, ideally with Umik microphone. And to get vertical vs horizontal placement in-room frequency response. By the way, thanks @bobopich for your contribution.

 

[KMO]

Typical user positions are vertically above center channel loudspeaker and in a wide horizontal arc, so both horizontal and vertical measurements are necessary.

Given that they are intended for wall mounting, an on-axis freestanding measurement is inappropriate in two-ways. All 5 speakers when mounted flat on the wall would be "horizontally" off-axis to the listener (the L+R even more than the centre), and be getting wall bass reinforcement.

So I'm not surprised to see them having anechoic on-axis high treble to offset both of those factors. And the "Selecta-mount" stand reduces the treble.

Wouldn't touch this myself, except maybe I could see it as a ceiling Atmos top speaker. I've seen a few people using T301 or T101 for that.

But this is 11-year-old, totally passive tech (pretty much the oldest thing in KEF's current range). DSP like that Ikea/Sonos thingy seems more promising...

 

[Vladimir Filevski]

Well, no, a 2.5-way design has only one crossover frequency, otherwise it would be 3-way. Rather it's one crossover, and one low-pass-filter.

Well, that might be semantic, but if we define the crossover as a circuitry which splits input signal in two or more frequency ranges, than 2.5-way crossover splits input signal in three frequency ranges.
3-way crossover splits input signal in three frequency ranges also, but one range of them is bandpass.
So, 2.5-way loudspeaker must have two crossover frequencies - one for both tweeter and midbass. and one for the woofer.

 

[Vladimir Filevski]

Given that they are intended for wall mounting, an on-axis freestanding measurement is inappropriate in two-ways. All 5 speakers when mounted flat on the wall would be "horizontally" off-axis to the listener (the L+R even more than the centre), and be getting wall bass reinforcement.

So I'm not surprised to see them having anechoic on-axis high treble to offset both of those factors. And the "Selecta-mount" stand reduces the treble.

I concur the freestanding measurement is inappropriate for wall-mounted speakers, but when speaker is mounted on-wall it is easy to calculate horizontal and vertical angle to the listener, so horizontal and vertical measurements show all you need to know about the mid-high frequency response at the listener point.

On the contrary, "Selecta-mount" reduces the bass, making the prominent treble even worse:
https://us.kef.com/explore-kef/kef-innovation/selecta-mount

 

[Madjalapeno]

This is the only picture I could find with the grill off.

Bookshelf Speakers | Accessories4less

www.accessories4less.com

 

[dasdoing]

Typical user positions are vertically above center channel loudspeaker and in a wide horizontal arc, so both horizontal and vertical measurements are necessary.

you didn't understand. the horizontal should be meassured while veriticly off axis (above)

 

[PeteL]

you didn't understand. the horizontal should be meassured while veriticly off axis (above)

Amir likes standardized tests for all speakers, that can be debated but in what you ask finding one correct height above that represent listener position is a bit arbitrary. It is measured at all position, this give the general behavior on all axis, I know you'd like a 2D graph with numbers, but:

 

[Vladimir Filevski]

you didn't understand. the horizontal should be meassured while veriticly off axis (above)

You can find frequency response at any point in 3D space, combining both measured graphs - horizontal and vertical.

 

[dasdoing]

Amir likes standardized tests for all speakers, that can be debated but in what you ask finding one correct height above that represent listener position is a bit arbitrary. It is measured at all position, this give the general behavior on all axis, I know you'd like a 2D graph with numbers, but:

that graph is hard to read, and limited to frequency. it seams to be wider above the axis (where it would matter more).

the thing is I think it is a little counter-productive in this case. If I buy this I want the manufactor to dail it in in a way it will be used. If you dail it in like the Klipple meassures it gives you a better preference, but it wont translate

You can find frequency response at any point in 3D space, combining both measured graphs - horizontal and vertical.

that's not true. if you have 2 slices only, you cant recreate the whole 3d response from it

EDIT: here, the in-wall is put into it's usage context https://www.audiosciencereview.com/forum/index.php?threads/revel-w990-review-in-wall-speaker.25954/