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 

A mix of cs-9 and pl301
Goto page Previous  1, 2, 3, 4  Next
 
Post new topic   Reply to topic    SpeakerTalk Forum Index -> DIY with KEF drive units
View previous topic :: View next topic  
Author Message
gforse
Junior Contributor 20+


Joined: 25 Jan 2010
Posts: 24

PostPosted: Wed Feb 03, 2010 11:24 pm    Post subject: Reply with quote

bud what is now the advantage of a box type of that?

is the 107 a bassreflex? where does the sound come out? out of the bottom?

and i have 1 pair of b300 and ma by soon a complete pair of 105/2 ( tops and woofers)

i would like to see B300B in the front and the b300 inside the chamber.

bud what is the best box with the most output bud still digs deep in the bass!?
Back to top
View user's profile Send private message
Lee in Montreal
Senior Contributor 200+


Joined: 22 Aug 2009
Posts: 203

PostPosted: Thu Feb 04, 2010 12:17 am    Post subject: Reply with quote


_________________
Kef Calinda - since 1979
Kef Cantata - since 2009
Kef 105/2 - since 2009
Evo 105/2 - in the build
Back to top
View user's profile Send private message
gforse
Junior Contributor 20+


Joined: 25 Jan 2010
Posts: 24

PostPosted: Thu Feb 04, 2010 9:49 am    Post subject: Reply with quote

so the theory of the 107 is that is a bass-reflex and its in isobaric so the sound and the bass will go deep with good output?

But i found it a shame that i cant see a B300B any more...is there maybe another box type that get the max out of it? and it has the b300B in the front and the b300 inside?
Back to top
View user's profile Send private message
Lee in Montreal
Senior Contributor 200+


Joined: 22 Aug 2009
Posts: 203

PostPosted: Thu Feb 04, 2010 2:31 pm    Post subject: Reply with quote

gforse wrote:
... and it has the b300B in the front and the b300 inside?


Why don't you try that and report? Wink
_________________
Kef Calinda - since 1979
Kef Cantata - since 2009
Kef 105/2 - since 2009
Evo 105/2 - in the build
Back to top
View user's profile Send private message
gforse
Junior Contributor 20+


Joined: 25 Jan 2010
Posts: 24

PostPosted: Thu Feb 04, 2010 2:55 pm    Post subject: Reply with quote

because i don't now how to begin. bassbox doesn't now a box type like that. i have also LinearX leap 5 bud that's way to difficult for me...

So how do i design a box type like that?
Back to top
View user's profile Send private message
Lee in Montreal
Senior Contributor 200+


Joined: 22 Aug 2009
Posts: 203

PostPosted: Thu Feb 04, 2010 4:34 pm    Post subject: Reply with quote

gforse wrote:
because i don't now how to begin. bassbox doesn't now a box type like that.


Maybe there's a reason, buddy...
_________________
Kef Calinda - since 1979
Kef Cantata - since 2009
Kef 105/2 - since 2009
Evo 105/2 - in the build
Back to top
View user's profile Send private message
gforse
Junior Contributor 20+


Joined: 25 Jan 2010
Posts: 24

PostPosted: Thu Feb 04, 2010 5:11 pm    Post subject: Reply with quote

even linearx leap doesn't know a box type like that...

bud is don't understand the meaning of the 2 speakers that are mounted with the front into a chamber. why do the do that? in stead of mounting them with the fronts to each other?
Back to top
View user's profile Send private message
SaSi
Senior Contributor 200+


Joined: 24 Aug 2008
Posts: 223

PostPosted: Thu Feb 04, 2010 7:16 pm    Post subject: Reply with quote

The 107 is a 4th order bandpass enclosure with a port of substantial size giving output from the top front edge, right below and in front of the mid/high heads. Thus emulates as best as possible a single source on a 3 way loudspeaker.

The 104/2 is again a bandpass enclosure with the port being smaller in length.

WinISD can model 4th and 6th order bandpass enclosures.

Did several models using B139, B200 (several SP variants) and B300s. I am not sure I liked the result. Transfer function was too unstable with even small enclosure volume variations.

I've read that tuning these bandpass enclosures at KEF (matching the drivers with crossover components) was a nightmare. I don't like nightmares and I don't consider myself at the same level the top KEF engineers were when they designed these speakers. Actually I'm way below their level.

A paper on bandpass enclosures was promised for posting here but still hasn't arrived.
Back to top
View user's profile Send private message
gforse
Junior Contributor 20+


Joined: 25 Jan 2010
Posts: 24

PostPosted: Thu Feb 04, 2010 7:59 pm    Post subject: Reply with quote

but if I compare everything, is the closed housing 90L still very beautiful. I think the B300 is meant for a 80-90L sealed enclosure. Other models are made with the B300 are all sealed enclosures.

So I think the best and simplest is to go for a 90L closed housing.

maybe than two b300s in the baffle.

whether you think differently?
Back to top
View user's profile Send private message
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Thu Feb 04, 2010 8:00 pm    Post subject: Reply with quote

[quote="SaSi/]. I consider the T27 a better tweeter than the T52. My pair of T52s are fully working (I think) but the ferrofluid in these tweeters gives them a finite lifespan. Theoretically all existing T52s of the '70s are way past their useful lives. OTOH, all T27s I've listened to appear to be in excellent health. .[/quote]

I disagree, T52's never had ferrofluid, and many commented at the time that they were better subjective tweeters than T27's. They had lower resonance frequency which meant the AB network was not so necessary, whereas the T27 had resonance quite near to crossover which needed the AB network to compensate, T27's had better very high frequency dispersion owing to the smaller diaphragm, but in the 105 adjustable head the T52 was fine and had a smoother subjective sound.
Back to top
View user's profile Send private message
SaSi
Senior Contributor 200+


Joined: 24 Aug 2008
Posts: 223

PostPosted: Thu Feb 04, 2010 9:04 pm    Post subject: Reply with quote

Strange, I was under the impression that T52 were ferrofluid cooled. I'm probably wrong and it was only the T33 found on the 107s that employed ferrofluid.

I need to complete the restoration of the 105s and do some careful listening.
Back to top
View user's profile Send private message
speakerguru
VIP Contributor 750+


Joined: 18 Nov 2005
Posts: 954
Location: Green Hut, Tovil

PostPosted: Fri Feb 05, 2010 4:53 pm    Post subject: Reply with quote

gforse wrote:
so the theory of the 107 is .......... its in isobaric so the sound and the bass will go deep......?

No. There's nothing "isobaric" about any KEF coupled cavity. They are bass reflex boxes with the output from the driver blocked off. You only hear the port output. The port output from a reflex has a bandpass response. The upper cut off is often designed to be around 100-150 Hz.
Back to top
View user's profile Send private message
audiolabtower
VIP Contributor 500+


Joined: 06 Jan 2009
Posts: 544

PostPosted: Fri Feb 05, 2010 5:25 pm    Post subject: Reply with quote

SaSi wrote:
it was only the T33 found on the 107s that employed ferrofluid.


yes, I think I remember T33s started with ferrofluid.
Back to top
View user's profile Send private message
SaSi
Senior Contributor 200+


Joined: 24 Aug 2008
Posts: 223

PostPosted: Fri Feb 05, 2010 7:10 pm    Post subject: Reply with quote

audiolabtower wrote:
SaSi wrote:
it was only the T33 found on the 107s that employed ferrofluid.


yes, I think I remember T33s started with ferrofluid.

Now I have to correct you Wink

The first T33 was conventional. The R107 use a newer generation of B110 and T33.
Back to top
View user's profile Send private message
ColinR
Über Contributor 1000+


Joined: 31 Jul 2004
Posts: 1175
Location: Staffordshire

PostPosted: Fri Feb 05, 2010 7:18 pm    Post subject: Reply with quote

Very poor gentlemen Evil or Very Mad .

You've been reading to many sleazeBay adverts or sniffing snake oil.

Read this

http://www.kef.com/Resources/KEFUnits/A%20History%20of%20Kef%20Drive%20Units.pdf


and stop talking utter bollocks about ferrofluid T52s and T33s.

It only went in 4 Ohm SP1210 and 1191 - R1197x T33mkIIs and the "fat" KM1 tweeter.
_________________
This post or any other information supplied to this website or any other by myself is not available for any form of commercial purpose i.e. to hi-fi magazines or as sales and marketing material for sleezeBay or Audiodogging pimps and the like.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SpeakerTalk Forum Index -> DIY with KEF drive units All times are GMT + 1 Hour
Goto page Previous  1, 2, 3, 4  Next
Page 3 of 4

 
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