SpeakerTalk Forum Index SpeakerTalk
This forum has been set up to facilitate discussion of 1970s KEF speakers and drive units. The owner of the Forum has no connection with KEF Audio.
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

KEF 105 question
Goto page Previous  1, 2
 
Post new topic   Reply to topic    SpeakerTalk Forum Index -> KEF Speakers from the 1970s
View previous topic :: View next topic  
Author Message
rx7rotary
Intermediate Contributor 50+


Joined: 20 Feb 2012
Posts: 59

PostPosted: Mon Mar 25, 2013 7:54 pm    Post subject: Re: Quad protection Reply with quote

proffski wrote:
I'm lost guys, anybody seen the KEF 105 forum?


I started reading this yesterday and thought , perhaps I dont understand the lingo Wink
Back to top
View user's profile Send private message
proffski
Über Contributor 1000+


Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Mon Mar 25, 2013 8:08 pm    Post subject: Re: Quad protection Reply with quote

THe lingo is easy, now back to those 105s... Smile
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill
Back to top
View user's profile Send private message Send e-mail
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Mon Mar 25, 2013 8:27 pm    Post subject: Re: Quad protection Reply with quote

proffski wrote:
I'm lost guys, anybody seen the KEF 105 forum?


Well the 105 should be pretty protected by the big input cap from dc? Maybe not from rail to rail unstable oscillation though... Exclamation
Back to top
View user's profile Send private message
SaSi
Senior Contributor 200+


Joined: 24 Aug 2008
Posts: 223

PostPosted: Thu Mar 28, 2013 2:28 am    Post subject: Reply with quote

I'm currently driving my pair using a Technics SE-9200 power amp, rated at around 70 W per channel. I listen to them in a medium - small room and the sound output seems to nicely fill the room with plenty of headroom. Even at an average of 10W on average, they sound loud enough.

These are rated at 200W so a more powerful amp would provide more headroom than a 70W amp, if only by a few dB.

When I overcome my laziness, I have plans to drive them using a pair of bridged SE-9060 amps that would provide 180W/ch. I think that should be plenty enough.

I haven't cleaned the fuseholders and the banana plugs to the heads need some cleaning also. And I haven't recapped the crossovers. But they still sound awesome as they are.
Back to top
View user's profile Send private message
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Thu Mar 28, 2013 2:25 pm    Post subject: Reply with quote

Let's say the 105 is 86 dB/W at 1 m anechoic.
Room reflections generally accepted to add around 4 dB to the total sound.
So 1W gives now 90 dB in room.
Listening distance 2 m reduces to 84 dB, 4 m (pretty common listening distance) reduces to 78dB with inverse square law.
A second speaker adds 3 dB so now 1 W produces 81 dB in room.

Ten times power to 10 W gives 91 dB in room which is twice as loud.
So 100 W gives 101 dB in room.
Another 3 dB acoustic power in room (a small volume increase of 20%) is double amp power to 200 W for 104 dB.

All approx of course, but gives an idea of peak amp power required.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SpeakerTalk Forum Index -> KEF Speakers from the 1970s All times are GMT + 1 Hour
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group