SpeakerTalk

David · Posted: Mon Jun 25, 2007 3:01 pm Post subject: JR-149

Anybody have the JRs? I have had a set for a couple of years now and just picked up the LPA sub, that is one of the active sub units, Rogers produced. Any suggestions for set up? I am using a Dyna ST70 amp with a Audible Illusions Mod. 3 pre and Lp12/sumiko mmt/ denon dl103 front end.

Thx

David

ColinR · Posted: Mon Jun 25, 2007 4:22 pm Post subject:

David · Posted: Mon Jun 25, 2007 4:55 pm Post subject:

Colin right now the sub is run from the LPA unit which has a crossover in it as well as an amp to run the sub as a mono unit. The speaker connections go directly to the LPA and are split off to the monitors w/o alteration and then to the LPA to convert to mono and amplified.

Were you suggesting to run the LPA from the pre as opposed to the speaker outs? Would it be enough signal?

Thx

David

ColinR · Posted: Mon Jun 25, 2007 5:06 pm Post subject:

David · Posted: Mon Jun 25, 2007 5:08 pm Post subject:

thx Colin

David · Posted: Wed Jun 27, 2007 3:09 pm Post subject:

Colin, it didn't work running from the pre outs. The gain was too small. Would have to mods to the LPA to operate like you suggest.

David

Micromegas73 · Posted: Wed Jun 27, 2007 3:44 pm Post subject:

Hello David,

I'm a David myself Wink

I have a pair of JR149 too. Great little speakers ! I don't know the LPA sub, maybe a picture could help...
And the ColinR's suggestion should be a good one too: my pair of JR149 had a "tired" crossover, Graham Hartle made me a new one. The man apparently knows very well the work of Jim Rogers.

see you,

David.

David · Posted: Wed Jun 27, 2007 4:04 pm Post subject:

David, I made the Type 24 crossover myself, using the plans on Graham's site. Cost me nearly the same as Graham's but at least I avoided duties. I made them outboard and also kept the old crossovers and made them outboard as well. The sub makes a big difference in bass reproduction, duuh. Just have to be careful not to crank it up too much.

Here is a link to the LPA system. There was also a passive sub and another active system the EX that could be connected to a pre out, and had a separate 60 watt amp.

http://cgi.ebay.co.uk/Superb-JR-149-JR149-subwoofer-with-LPA-amplifier_W0QQitemZ180130515149QQihZ008QQcategoryZ14991QQcmdZViewItem

David

ColinR · Posted: Wed Jun 27, 2007 7:53 pm Post subject:

David · Posted: Wed Jun 27, 2007 8:04 pm Post subject:

thx Colin.

The JR literature indicates that the LPA runs the JR149s throughout their range, that is w/o any frequency shaping. the LF signal is supposedly taken from the speakers from the amp, and extracted for the sub, which is driven by the LPA amp.

Yes I could run another amp into the LPA from my Pre and run my ST70 directly from the pre as well, or

Just look for a sub amp with a line in feature. I have some spare integrateds around that I can play with to see if there is any difference.

I take it you are suggesting the signal would be cleaner for both sub and satellites w/o having to pass both through the LPA.

David

ColinR · Posted: Wed Jun 27, 2007 8:45 pm Post subject:

David · Posted: Wed Jun 27, 2007 8:49 pm Post subject:

Thx Colin,

Will be easy to give it a go. The theory that the original signal can go to the satellites w/o any changes, but that the LF can be channelled off sounds too good to be true.

David

ColinR · Posted: Wed Jun 27, 2007 8:56 pm Post subject:

Micromegas73 · Posted: Thu Jun 28, 2007 5:47 pm Post subject:

David · Posted: Thu Jun 28, 2007 9:39 pm Post subject:

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

I separated the satellites and sub last night as per Colin's suggestion and the change was remarkable. A lot more detail from the satellites.

Thank you Colin.

David