SpeakerTalk

David · Posted: Fri Jun 29, 2007 2:34 pm Post subject:

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

Micromegas73 · Posted: Fri Jun 29, 2007 5:39 pm Post subject:

David · Posted: Fri Jun 29, 2007 6:36 pm Post subject:

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

Cloth ears · Posted: Sat Aug 11, 2007 6:20 pm Post subject:

Hi David,

My first post.

I am not very technically minded, but I´m 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
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ColinR · Posted: Sat Aug 11, 2007 8:44 pm Post subject:

Micromegas73 · Posted: Fri Sep 28, 2007 7:32 pm Post subject:

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.

ColinR · Posted: Fri Sep 28, 2007 7:52 pm Post subject:

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

.
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Micromegas73 · Posted: Sat Sep 29, 2007 11:15 am Post subject:

I was completely wrong then...thank you Colin. Wink

roberte · Intermediate Contributor 50+ Joined: 20 Sep 2006 Posts: 51

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'?

proffski · Posted: Sun Jan 17, 2010 6:07 pm Post subject:

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

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