TheDecameron
Unicorns fart glitter.
Are the crossovers entirely new? If so can you post a pic if it’s not too difficult. I’d love to hear a pair of these! The Falcon LS3/5as are superb.
Revisiting Jim Rogers JR149s
TheDecameron
Unicorns fart glitter.
And I’m not sure how much of a market there’d be for a speaker at such a premium over the already hefty price on the Falcon LS3/5as. You’d expect the JR remake to have a similar price. Does anyone know the comparative prices back when they were current?
ToTo Man
the band not the dog
What does this mean exactly? Hard to imagine a woofer being inserted any way other than the right way?!
I'm curious to know more about this "unbranded woofer". AFAIK there are very few drivers that match the PCD of the B110 so fitting a third-party driver would likely necessitate modifying the baffle cutout or screw holes or using spacers to stand the driver off the baffle a few mm's. This is what I had to do when I tried Monacor SP-135TC drivers in my JR150, and I was unable to get a good enough air seal.
The left/right imaging on your JR149s must've been out quite a bit I'd have thought, especially in the midrange, since the JR149 crossover contains an "anti-quack" notch filter to reduce an upper-midrange resonance in the B110. If the "unbranded woofer" didn't have similar resonances to the B110 then I'd expect the JR149 crossover would make it sound thin/recessed in the mids. Had the crossover also been modified?
Tony L
Administrator
As with any new speaker they relax and open-up with time. I’d recapped my crossovers at the same time so they really were a brand new speaker. I’ve never thrashed them to speed any run-in up and they are sounding wonderful now. I’d say a month of typical use gets a speaker as good as its going to get, i.e. surrounds and spider are nicely bedded-in, caps fully re-formed after sitting on a shelf, in the box or whatever.
As stated up thread after some experimentation I really recommend keeping the crossovers stock, i.e. replace the tired electrolytics like for like, not with modern film caps. Also if yours have been botched about in the past chances are the tweeter level pot is not where it should be. Mine were cranked right up when I got them. I’d advise starting in the middle of the range and adjusting by ear. Confusingly clockwise is cut, anti-clockwise boost. I’ve ended up with a little cut. I’d also be inclined to check every resistor and capacitor value is as it should be, there is a schematic upthread. For some reason I really can’t explain mine had some slight resistor value differences left to right, which I’ve now addressed (I’ve replaced everything, but just with good quality equivalents, nothing ‘fancy’).
Tony L
Administrator
Out of phase I guess.
ToTo Man
the band not the dog
Ah, I was thrown by the "inserted" descriptor into thinking it was to do with the physical orientation of the driver!
If indeed out of phase, I'm surprised this anomaly wasn't obviously audible during listening. Unless the responses of the two woofers were so drastically divergent that wiring one out of phase didn't result in the degree of bass cancellation that would typically be expected?!
retrospective
pfm Member
Having recently purchased some B@W DM5's which were hot on the Jr149's heels in the 70's Hifi for pleasure supertest.
I'm curious to try some 149's and i'm wondering how they differ? If it would be more or less a sideways step?
Tia
I'm curious to try some 149's and i'm wondering how they differ? If it would be more or less a sideways step?
Tia
mandryka
pfm Member
A MONTH!!!! I can’t wait a MONTH!!! I’ve tried to accelerate the process by playing radio constantly for the past two days, at low volume. And I just put some music through there and you know what . . .I think it’s working.
Tony L
Administrator
I remember decades ago buying a brand new pair of Linn Kan IIs and a friend popping round hearing them, and not liking them much. He then popped back about three months later and loved them, asking what the hell I’d done! I’d barely noticed the change beyond I was enjoying the whole system more as for me it was so gradual.
Operajulian
Julian
Having both of these speakers in the home - as mentioned in other posts. Much as I like the DM5 for pushing out the volume - my daily listen speakers are the JR149. Purchased on a whim from a Toronto secondhand dealer ( no longer in business ). I live in a smaller house so the JR149 are also more in keeping with our decor and don't fill the room physically.
The DM5 are in the basement for when I just want LOUD.
Both are really good but the JR149 just is a bit better for me.
I am sure others will come along with their opinions......
Julian
ToTo Man
the band not the dog
Do DM5's go loud? They don't look much larger than the JR149 to me and, being from the same era, I wouldn't have thought the drivers were designed for high excursion and/or high power handling. I wouldn't like to try to push my DM4's much louder than my JR149s or JR150s...
ToTo Man
the band not the dog
I wouldn't have thought an extra 1.3cm of cone diameter would have made that much difference on its own, but the JR149 does use a fair amount of BSC. I don't know how much BSC is employed in the DM5 but I assume it's less than the JR149, which should in theory mean it less excursion than the JR149 to achieve the same SPLs.
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Tony L
Administrator
I remember from my Kan days it is not hard at all to ‘bottom’ a B110, especially with an LP12 and a techno 12”! I have some records that I had to listen to very quietly on that system, though some of that might have been subsonic guff from the LP12’s subshassis etc. I don’t think I’ve ever got even close to upsetting the 149s, though they have a digital source. I don’t recall ever bottoming my first pair of 149s as a teenager either, and that was a vinyl-only system.
ToTo Man
the band not the dog
I've never heard Kan's but folk tend to categorise them as bright and forward, don't they? But Kan's presumably use BSC on the B110? Is it just the upper frequency B110 breakup they don't correct for?
I have a pair of IMF MCR2A cabs with B110s and T27s fitted. These are very bright and forward, perhaps the most bass-shy speaker I've heard. Having previously peered inside one to look at the crossover and finding an extraordinary volume of lambs wool that I tried my best to move out of the way, I could only see a single inductor and cap, which suggests a simple 1st order crossover, but I may have missed the other components. There's no way I could bottom out the B110s on those, even at my loudest comfortable listening levels the cones were barely moving, presumably due to the complete absence of BSC! I really out to dig them out and measure their FR!...
Tony L
Administrator
Mine were Kan IIs, which had a slightly more complex crossover than the MkI, but still minimal compared to a JR149 or LS3/5A. I don’t know the details, but my guess is the Kans have no baffle-step correction and get around it to some degree by requiring hard against back-wall placement.
Kans are one of those speakers most people setup terribly or in entirely the wrong room so they have a real love/hate reputation. Setup well in a small room with a good floor and solid back wall they are great fun, crisp, open, surprisingly dynamic and capable of very articulate and (for their size) surprisingly extended bass. If you think of JR149s as having say a Sennheiser HD-600 balance Kan IIs are the most lively Grados by comparison, but neither is harsh.
The other thing to factor with Kans is they were very much a Linn/Naim system speaker, so they were voiced to sound right on the rather over-warm LP12 of the time and the nice weighty and dynamic chrome-bumper-era Naim amps such as the 32/Hi/250 etc. Move too far from this context and they just won’t work. They are in no way all-rounders like the LS3/5A, JR149, various little Spendors etc which find a context in many near-field systems valve or solid state.
Martyn Miles
pfm Member
I recall Falcon attempted a remake of the JR
149, but decided not to go ahead.
Can't remember if I saw a prototype when visiting Jerry Bloomfield, or a picture somewhere.