Kef T101 vs T301 for front LRC speakers

[Rocketrazor]

Hi All,

So were decorating the lounge and one option that has come up is to replace my current Mission M74 floor standing speakers with Kef T wall mounted speakers. This would give the room a better look and most importantly allow me to fit in a projector, something I can't do keeping the Mission's! I have a sub to take care of the bass duties but I'm wondering if I'm better off considering the 101's or 301's for the front LRC?

A few things I've considered

• My lounge is only 3.27 mtrs wide so I'm not that far from the speakers.
• I'm aware that the Kef's use the wall to help them out, but these will be mounted on the wall to next door to help hide their noise! I don't really want to start a 'sound war' with them so I'm a little concerned about the effect on them.
• I'm planning Kef T101's for rears.
• It's an open plan lounge/dinning room/kitchen as an L shape and these will sit on the long wall between lounge and dinning room meaning sound could 'escape' into the dinning room.
• I'm trying to avoid ordering both, trying them out and returning one of them as it will lose the retailer money doing this.

Any advise as to if the T101's or T301's would be better would be appreciated.

Cheers

Rocket

 

[Gasp3621]

If you look older threads you will find out that T301 and T301C is highly recommended over T101 for the LCR! People who has heard have said there is noticeable difference. This is not hard to believe as they are ultra slim speakers with small driver(s).

Do you have space for normal sized center channel below screen? You could then consider Dali Oberon On-Wall and Oberon Vokal.

 

[Rocketrazor]

I believe I have found the thread you referred to, thank you.

I was looking at the Dali Oberon originally but the idea is to have a UST projector and either a drop down or raising UST ALR AT screen drop/raise in front of the TV and speakers. The Oberons were just too large to enable this to happen as they are 12 cm's deep against the T301's at 3.5 cm's.

Cheers

 

[ShanePJ]

The T-305/T205 system is a much better solution T-105, do be aware that all the speakers really need to be wall mounted as I have found them to be poor on the t-series stands which alter the crosser going to the speaker. I was always told by the Kef engineers that wall mounting them allowed the speaker to use the wall for more of a sound stage.

Now I can see you're also looking at a UST projector and I'm not 100% sure whether you can gain the height required to mount the T-301c below the screen as I feel the projector will be in the way of the centre channel. So would you be ceiling mounting the UST?

 

[Rocketrazor]

Hi,
The UST screen will not be fixed, it will be an Acoustic Transparent one that drops down or raises over the TV and speakers if I go for on wall speakers.

I am confused with all the frequency notes for different speakers though. My current setup is

M74 fronts
Recommended Amplifier: 25 - 150 Watts
Frequency Response: 44Hz - 20kHz
Sensitivity: 91dB
Nominal Impedance: 8 Ohms

M7C center
Recommended amplifier: 25 to 100 watts
Sensitivity: 87dB
Nominal impedance: 8 ohms
Frequency response: 75Hz - 20kHz

M7D
Frequency Response: 75Hz - 20kHz
Sensitivity: 89 dB
Crossover Frequency: 2.8kHz
Effective Volume: 4.2 Litres
Nominal Impedance: 8 Ohms (min. 4.2 Ohms)
Recommended Amplifier Power: 25 - 100 Watts

And a BK P12-300SB Sub.

My Marantz sets the cross over at 80Hz for M74 and M7C, 100Hz for M7D.

The T301's are spec'd at

Amplifier Requirements: 10 - 150 W
Sensitivity: (2.83V/1m) 88dB (floor stand mount)
Impedance: 8 Ohms
Frequency Response: 80Hz - 30kHz
Crossover Frequencies: 1.7kHz

I don't understand the Crossover Frequency, if my M7D says 2.8kHz but the Marantz has decided 100Hz?
I understand that the Sensitivity is how hard they need driving, so the Kef's will need driving harder than my M74's.
My main concern however is the Frequency Response.

M74: 44Hz - 20kHz
M7C: 75Hz - 20kHz
T301's: 80Hz - 30kHz

I read somewhere that the human ear can't hear above 20kHz, so why do the Kef's go to 30kHz? I read somewhere else going higher can sometimes improve the lower performance!

There is a difference of 36Hz from 44Hz to 80Hz in the fronts comparison. This means the cross over would be higher meaning the Sub would have to work harder, but also I don't always turn the Sub on for TV, or when something is 2 channel only, but how much is in the 44Hz to 80Hz, i.e. what would I miss using the Kef's over the M74?

I'm starting to toy on seeing if I can keep the Missions, see if I can get a screen above them, can't put them to the side of the screen, just to wide for the lounge. It would be a little high but I'd get used to it. The center channel would sit below the screen and projector, again not ideal, but I might have to compromise somewhere. Oh the joys of the home cinema hobby

 

[Conrad]

The crossover listed against a speaker will be the internal crossover between the mid driver and the tweeter. The crossover that the AVR sets is the low end crossover when the speaker hands over to the sub.

Usually that low end crossover should be an octave or so above the speakers lowest frequency. So if the fronts are good down to 44Hz, an 80/90Hz crossover is fine. Where the speakers lowest frequency is higher, like the center, you'd probably want a higher crossover - about 120Hz in that case. This is so that you're not asking the speaker to play frequencies that would stress it or make lead into distortion.

Sensitivity is just that, it's how much output you'll get from a given input power, in this case 2.83v (which I think is 1w). In your case the fronts will play louder than the center for the same given input. Don't worry too much about that though, the AVR will take care of the levels - which involve distance as well as sensitivity (the further away they are the quieter they'll be). You don't really need to worry about sensitivity until you see figures in the low 80s or very high 90s and 100s, but this is uncommon.

80Hz is a pretty high lowest frequency for a speaker. I'm not familiar with them but they must be quite small. I wouldn't want to run them without a sub.

 

[Rocketrazor]

Thanks Conrad, I was particularly interested in your below comment

"Sensitivity is just that, it's how much output you'll get from a given input power, in this case 2.83v (which I think is 1w). In your case the fronts will play louder than the center for the same given input."

This explains why on my previous amp with no room correction I had to set my Centre 3-5 db higher than my fronts as I felt it was being dwarfed by them, I never knew why!

As part of the room redecoration we have changed the set up temporarily to get a feel for what we are proposing, I haven't run room correction yet as I don't have the rears and sub plugged in, but I was surprised at just how much lower I now need the sound, on the same setting as before it's just too loud and gives me ear ache. We only moved about 1 mtr closer. Given I'm now potentially going to listen at a lower level do I have a possible issue where some sounds wont be heard, i.e. you need the volume louder for the speaker to produce them/you hear them? I know when I played with the sub on first setting it up I found a scene in Transforms Age Of Extinction where the Dinobots hold the bridge. There is a part where if I turned the sub down too much I couldn't hear it, so I set the volume just above this sound. I'm a little worried that listening lower will mean I don't pick up everything I currently do with the exact same setup?

 

[Conrad]

this shouldn't be an issue, but its something to watch/listen for.

By sitting 1m closer the sound is less dispersed, it has less air to move before it gets to you, so less movement by the speaker results in the same level at your ear. I think it's 6dB per 1m, but that might be outside, I think it's about 3dB a meter in room. Anyway, the point is that it'll be louder if you sit closer.

In theory, turning the volume down will drop the levels at all frequencies equally. Combined with you moving closer the resulting sound should be the same. But I don't know that it works that way in practice. Some speakers need to be fed a good level for them to really "come alive", mine are a bit like that. They're good at low levels but they really show their stuff when you turn things up a bit.

My theory here isn't great, but I agree that there might be occasions where you'll lose some detail because the level of that detail is so low. I guess test it? Things like a quiet place are good soundtracks for little details. Find a passage that you can hear details in, turn things down and sit next to a speaker, see if you still hear the same level of detail.

 

[Rocketrazor]

Thanks for the clarification, it's nice to bounce these thoughts off someone else!

On another note, found out the screen I was looking at is only AT at the very top, not all the way through (not surprised given it's only £50 more than a none AT). This rules out putting them on the wall so just have to worry about my existing ones now and if to upgrade to a smaller floor stander like the Dali Oberon 5's (which the better half hates the look of anyway!)

Thanks again

Rocket