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 

JR-149
Goto page Previous  1, 2
 
Post new topic   Reply to topic    SpeakerTalk Forum Index -> Other speakers
View previous topic :: View next topic  
Author Message
David



Joined: 11 Jun 2003
Posts: 90
Location: Canada

PostPosted: Fri Jun 29, 2007 2:34 pm    Post subject: Reply with quote

Sorry I wasn't more specific on re routing the LPA, but ran out of time. The LPA crossover appears to rob the dynamics, frequency response, depth and imaging from the satellites. The volume setting on my pre goes down appreciably when the LPA is not connected through the speaker outs. Having heard both set ups, I would never go back to using the LPA crossover with the satellites. It is like night and day. The sub works fine through the tape outs and a receiver, although every time you adjust the volume on the satellites, you have to balance the sub separately.

Colin you are right, Rogers didn't put too much effort into the LPA. He could and should have done a lot better, but then, when he did it how many subwoofer systems were around.

David
Back to top
View user's profile Send private message
Micromegas73



Joined: 18 Jun 2007
Posts: 14
Location: FRANCE

PostPosted: Fri Jun 29, 2007 5:39 pm    Post subject: Reply with quote

David wrote:
Outboard means that they are in a separate box, outside the enclosure.

David



ok, because originally they are yet outside the wooden enclosure just below the metallic "lid" where it is written "JR". Mines are gold logo by the way.
Back to top
View user's profile Send private message
David



Joined: 11 Jun 2003
Posts: 90
Location: Canada

PostPosted: Fri Jun 29, 2007 6:36 pm    Post subject: Reply with quote

Yes mine are the gold logo as well. They are the later version, and have a slightly different crossover than the red logo.

Mine are rosewood with leather inlays. The sub is yew, which is a very distinct look. I got the foam surrounds from Graham, to get the real JR look. Talk about obsessive.

David
Back to top
View user's profile Send private message
Cloth ears



Joined: 11 Aug 2007
Posts: 8
Location: Barcelona

PostPosted: Sat Aug 11, 2007 6:20 pm    Post subject: Reply with quote

Hi David,

My first post.

I am not very technically minded, but Im learning Very Happy

I have an interest in JR149s. I have one pair of JR150s, three pairs of JR149s, an LPA MK3 and the JR Sub. (I intend to kit out a home cinema ).

The woofer in the sub was updated to a SEAS CA25RE4X/DC, a 10" unit.

I have some notes from JR regarding the LPA with specs and a Data sheet showing roll off at 80Hz. I can scan these for you if you wish.
The notes state:- "frequency response 20HZ to 100HZ and 24 octave slope. Slope control +8DB at 20HZ. Power out put 30 Watts into 8 ohms Suitable for bass loudspeakers 4 to 16 Ohms."

I connect the sub through the LPA to the 8 Ohm speaker terminals of my Rogers/Audio-Note E40a tube amp. It does not detract from the main speakers as you seem to be experiencing.

By the way, one of my sets of JR149s seems a little peculiar, they dont have the JR logo on the bottom (front) but they do have a proper JR sticker on the bottom (underneath). Also the wooden tops are a little thinner that my other 149s Shocked Can anyone shed any light?

Great site guys, glad I found you. I will be posting a couple of queries soon in the right places once I learn to navigate my way around.

Regards
_________________
Simplest Hi-Fi tweak is to syringe your ears.
Back to top
View user's profile Send private message
ColinR



Joined: 31 Jul 2004
Posts: 1175
Location: Staffordshire

PostPosted: Sat Aug 11, 2007 8:44 pm    Post subject: Reply with quote

Quote:
By the way, one of my sets of JR149s seems a little peculiar, they dont have the JR logo on the bottom (front) but they do have a proper JR sticker on the bottom (underneath). Also the wooden tops are a little thinner that my other 149s Can anyone shed any light?


I had this discussion with Graham Hartle some time ago.

The Aluminium side walls in both 149 & 150s became thinner and the tops shrank as Jim drove down costs to maintain profitability.

No idea about the logos though.

Because of his interest in Rogers designs, Graham (a cabinetmaker) produces a stonking powered sub for the little 'uns Smile .

http://www.jr149.pwp.blueyonder.co.uk/JR%20149.htm
_________________
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 Send e-mail
Micromegas73



Joined: 18 Jun 2007
Posts: 14
Location: FRANCE

PostPosted: Fri Sep 28, 2007 7:32 pm    Post subject: Reply with quote

Hello guys,

I'm looking for the right information about the sensitivity of the JR149 model. The documentation from that era seems to indicate 90dB, but some people around me are convinced they are just a little bit better that the LS3/5a on that matter.
I simply don't believe them for many reasons, but 90dB seems to me maybe a little optimistic...then if any of you knows the truth...

Thank you,

David.
Back to top
View user's profile Send private message
ColinR



Joined: 31 Jul 2004
Posts: 1175
Location: Staffordshire

PostPosted: Fri Sep 28, 2007 7:52 pm    Post subject: Reply with quote

Er if you're making up a speaker using drivers with 85dB/Watt and 84dB/Watt sensitivity, crossover losses will reduce this to 83.5dB/Watt at the very least.


The JR149 sesitivity is 83dB for 1Watt at 1 metre Cool .
_________________
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 Send e-mail
Micromegas73



Joined: 18 Jun 2007
Posts: 14
Location: FRANCE

PostPosted: Sat Sep 29, 2007 11:15 am    Post subject: Reply with quote

I was completely wrong then...thank you Colin. Wink
Back to top
View user's profile Send private message
roberte



Joined: 20 Sep 2006
Posts: 51

PostPosted: Sun Jan 17, 2010 5:55 pm    Post subject: Reply with quote

As I've just acquired some 149s I thought I'd re-open this thread.

Firstly: they are gold logo with a fuse in the (circular) cross-over and paper stickered serial numbers in tact on the bases (same 5 digit serial number on both).

As far as I have read so far, this makes them quite late, but not type 24 square circuit board early 90s late.

The drivers look correct - but to get closer to the fronts would mean removing a large number of staples which hold the aluminium grills in place wouldn't it?

Inside I have only looked as far as the cross-over so far.

One thing I hadn't realised is that they use a B110 A.

First question that springs to mind is that without the B139 and the huge cabinet of my KK3s how are they producing that bass?

More technically: how much lower is the B110 going than it would do in a three way?

Next: any advice on the variable resistor for adjusting the tweeter?

Lastly: have had a look through Graham Hartle's site and though I haven't been in touch with him yet I guess it won't be long; can anyone confirm that he is still 'in business'?
Back to top
View user's profile Send private message
proffski



Joined: 22 Aug 2003
Posts: 1168
Location: Tewkesbury UK

PostPosted: Sun Jan 17, 2010 6:07 pm    Post subject: Reply with quote

There is plenty on the Interweb regarding the JR149 and this is a nice one, probably already mentioned on this forum: http://www.jr149.pwp.blueyonder.co.uk/The%20crossover%20to%20149-4.htm

Sorry if you have already seen it. 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
Display posts from previous:   
Post new topic   Reply to topic    SpeakerTalk Forum Index -> Other speakers 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