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JR 149s
On Wednesday, June 5, 2019 at 1:12:27 PM UTC-4, Howard Stone wrote:
What are people's experiences with JR 149s? I have a pair being driven by a Quad 520 . The sound is not very satisfactory -- it sounds "amplified" I wonder if people have found a really successful amp for them. Someone I know loves the sound he gets out of them with a leak ST20. Thats 10W per channel. But it turns out that he listens very vert close and very quietly. I want to be able to listen in a smallish room -- 15'x15' -- though not to loud music -- a harpsichord or a handful of voices max or a few string instruments max. And then there's the question of positioning. Does anyone think that the wall brackets Jim Rogers produced are a good idea for the sound? I have mine on stands but close to a wall, 10'apart. Oh my source is an old Deltec Bigger Bit DAC; no preamp. I'm toying with the idea of getting a PASS Aleph 30 clone for them. It may be that these speakers were designed for near-field monitoring and it's just not possible to get a satisfactory room filling sound from them. The JR's are very much based on the BBC LS3/5a design,. It uses the same KEFB110/T27 set of drivers and a somewhat similar crossover. Both of these drivers are VERY good, but especially the B110, it's a 5" mid/woofer, perhaps on the best every made, but it's still only a 5" mid/woofer. Now, as to the design goals for the original LS3/5a, I would refer you to the original design brief, "There is a need to monitor sound programme quality in circumstances where space is at a premium and when head- phones are not considered satisfactory. Such circumstances include the production-control section of a television mobile control-room, where the producer responsible for the overall production of the programme needs to monitor the output from a sound mixer but at levels lower than those used for mixing." Hardwood, Whatton and Mills, "The Design of the Miniature Monitoring Loudspeaker Type LS3/5A", BBC RD 1976/29, pub. Research Dept., Eng. Div. British Broadcasting Corporation, 1976 October So, imagine a large trailer pulled up to a remote venue, and said trailer is divided into several "rooms", one of which is for the final monitoring of the "programme". Said trailer might be 10-12' wide, and the room might be 8-10' long. The producer might be sitting in front of a console, and as a result the producer listening might be sitting all of 5-6 ft away from the speakers, which themselves might be 4-6 ft apart. This is the scenario the speakers were designed for. Your friend's scenario is much closer to the design intent than yours. As to what amplifier is "best", I think that is, at best, a tertiary issue. The venue and use scenario is the dominating set of limiting factors. I would posit, and be willing to back it up objectively, that, used in the right way, it makes little if any difference whether you're using it with a quad 520 (100+ watts/ch), a Leak, a Pass or whatever up to the level common to what all of them can produce without distortion. The point being that the speakers were intended for moderate monitoring in a small venue. What subsequent uses were invented by the high-end, and claims about the suitability in those scenarios, is another question altogether, and, like much in the high0-end, may not be constrained by inconveniences like facts, physics or reality. As usual. |