dubai2000 Posted September 8, 2004 Share Posted September 8, 2004 Sound advice - thanks for the clarification about this polarity issue. So let my ears rule ! Wolfram Quote Link to comment Share on other sites More sharing options...
ZAKO Posted September 8, 2004 Share Posted September 8, 2004 The way I see you,r picture..... with the 2404 mounted to the side of mid horn... I can see a problem with cavity effect... the 2404 should be mounted on verticle plane to mid horn plus some baffle board around each. Cavity effects can be severe. Now I,m shure this is what,s messing with image. Paul Klipsch warned about this and published it in one of his papers. I tried this side treatment of tweet many years ago, Didnt like it. Image swished around & wouldnt lock in. Tweeter should be centered above or below mid unit. Depending on how long your neck is. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 8, 2004 Author Share Posted September 8, 2004 Yep, Maron, probably quite true. However, I'm not complaining about the imaging, it's just fine. Actually, it's better than fine. The part that throws me is the "apparent" phase reversal when the tweet is turned vertical in the same location - that is a stumper! But you're probably right, there are alot of "unseen" issues going on there, and cavity effect is as likely as any... I didn't know what I was biting off when I got these. I'm sold now, but their "care and feeding" was something that I was not aware of... DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 Well, its been a few weeks, and here's my final review: It's been a long haul, and the main thing that I learned was THESE HAVE A PRONOUNCED BREAK-IN PERIOD... Everyone who has recently listened to my system has agreed that the JBL's are an immediately noticable improvement (from about the first note of listening) to the overall sound. Not one negative comment...everyone agrees that they are bright, but not unpleasantly so (which is good because I'm running them wide open, as I mentioned earlier). They are bright and exceptionally clear, and (this is weird) they also tighten up the bass, and increase rythym and punch. There is no "lag time" that one can discern between the bass and the high-end, it is one seamless extention from one end to the other. Overall the quality of "realism" is definitely increased, in particular on a well-recorded orchestral piece with the original spacial volume of the recording hall seemingly replicated in my listening space. Performers turning pages of music over or setting down bows, etc. are a noticable part of the performance. I get a strong visualization of the layout, like where each orchestra section is placed, where the tympanies are located and how far away they are and the like. I can hear the oboe-ist breathe in certain solo passages. DeutchGrammophon "Ravel - Bolero" cd, for instance - not Bolero itself which gets quite boring IMO, but the other Ravel pieces are superbly recorded and musically delicious (DEAN). It's an easy escape into the music, it requires no concentration...it is simply just "there"; layed out before you, open and unrestrained, effortless, and seemingly as dynamic as reality. Another fun recording is (again) DeutchGrammophon "Ravel - Daphe et Cloe" which also has the Ravel (one of my favs) piece "La Valse". That particular, peculiar little piece can startle you into a heart attack! It never fails to startle me EVEN though I know it's coming! Now that's some GREAT LISTENING FUN! The startling quality of transients erupts from a completely black-space. Absolutely ZERO background noise. From virtually nowhere! Cymbals are cymbals, they shimmer and resonate like they really do, triangles are triangles, bells are, well, right over THERE. They don't waver or wander around, they have the expected substance and weight; they are entirely believable. They are coming from an EXACT point in space - not just from a plane between the speakers, but an absolutely convincing 30 ft away. The effect is so substantial that non-audiophile people ask if my room treatments are speakers... If some of you already have this going on (I had what I now regard as mere INKLINGS of the capabilities of the system, but at the time thought it was pretty good) prior to the JBL's, then you know what I am talking about. But I have to say that it has been a SUBSTANTIAL IMPROVEMENT to the "imaging" and "realism" compared to the previous performance capability which I was used to. I've now become used to a higher level of reproduction, plain and simple. A whole new level. That is saying alot. The ONLY complaint that I have now is the cost involved. That's the only bummer. Glad I got em anyway. I'm running ALK-A's which crossover at 375Hz (6db slope) and 6500Hz (18db slope?) which seem to work fine. I removed the fuses from the networks. Also have run well over +200 watts (possibly 300w) into the speakers for short periods (mainly sound-effects from movies) with no ill-effects. These JBL 2404H things are keepers... John Warren is right. DM Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted September 21, 2004 Share Posted September 21, 2004 Excellent update - if I may say so - and I agree: it's more or less impossible to go back once the JBLs have been installed. BTW: Which DG Ravel discs are you talking about (Karajan, Abbado?)? Wolfram Quote Link to comment Share on other sites More sharing options...
sunnysal Posted September 21, 2004 Share Posted September 21, 2004 thanks for the update, which way did you end up leaving the speakers? cheeks vertical (like a person) or cheeks horizontal? eletrical polatiry? let us know...my 2404Hs are in customs right now, I hope to install them within a week or two and will report back what I hear...warm regards, tony Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 Wolfram, Karajan, of course. DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 Wofram, now that you mention it, let me get back to you. (I'm at work and the cd's are at home)... DM Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted September 21, 2004 Share Posted September 21, 2004 I suppose Karajan has recorded more than one Ravel disc for DG (I guess analogue in the 1960s and digital in the '80s) - so which will it be? Just for the record: in my room the JBLs sound best with the slot being vertical and black connected to minus. Wolfram Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 Tony, mine are setup with the slot horizontal, and the black to + (for forward diaphragm movement according to the documentation which by the way did not come in the box - I downloaded a copy from John Warren's website). Vertical mounting did not work well for me at all. I can only attribute this to the back-lobing pattern of the JBL's being radically different depending on the orientation of the slot. P.S. you're gonna be very happy with these puppies. Like Wolfram said, you won't be able to go back... DM Quote Link to comment Share on other sites More sharing options...
sunnysal Posted September 21, 2004 Share Posted September 21, 2004 thanks! I thought that the "correct" mounting was crack vertical...is that right? that is how I saw this baby cheek type horn mounted on stock JBL speakers. maybe it will different with a baffle...hmmm...tony Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 The "correct" mounting is slot vertical. See John Warren's website for a pic. My particular situation is the exception to the rule, so far... DM Quote Link to comment Share on other sites More sharing options...
sunnysal Posted September 21, 2004 Share Posted September 21, 2004 ok just wanted to have the correct reference as a starting point. regaqrds, tony Quote Link to comment Share on other sites More sharing options...
Q-Man Posted September 21, 2004 Share Posted September 21, 2004 Now try to imagine what the speaker will sound like if you improve the midrange horn and driver to match the JBL tweeter. The Altec 311-90 horn with the Altec 290-16K driver is a combination that improves the midrange like the JBL tweeter improves the highs. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 21, 2004 Author Share Posted September 21, 2004 Q-man, great to hear from you! I have 2 questions: where can I get them and how much? DM Quote Link to comment Share on other sites More sharing options...
Q-Man Posted September 21, 2004 Share Posted September 21, 2004 They are very hard to find lately. I just bought my last needed pair of 311-90 horns. Now I have six of them for my home theater set up. I've had to pay up to $800.00 for a pair and seen them sell for $900.00 a pair. Sometimes you can steel them for $600.00. The 290-16K or L drivers sell for about $150.00 to $250.00 a pair. The drivers are a real bargin and can be repaired at Great Plains Audio, if needed. Bill at Great Plains Audio keeps telling me that he is going to start making the 290 again, but he has been telling me this for over a year now. Maybe I should tell him that there is becoming a demand for them again. I got one pair of the drivers from Jammin Jersey and the other two pairs from ebay. John and I may put our two heads together and experiment with some current midrange drivers and horns to compare with my tops. If we can come up with the right combination before going broke we might and I say might offer a top such as mine as a Klipschorn up-grade. To be honest with you we also don't think that Forum members will be the ones to market these tops to. People here don't seem to be willing to pay for such an up-grade. But we have been doing moods because we love to, so who knows what's going to come of it? I have been thinking of even making the 311-90 horn if I can't find one that sounds as good. Quote Link to comment Share on other sites More sharing options...
dubai2000 Posted September 22, 2004 Share Posted September 22, 2004 Q-Man, a smashing idea.....provided the price is right. Please let us know if some alternative to those Altecs comes up . BTW: could I upgrade my mids by using a different driver on my Cobreflex horns - without altering crossovers? Wolfram Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 22, 2004 Author Share Posted September 22, 2004 Q-man, sign me up, too... DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 22, 2004 Author Share Posted September 22, 2004 Wolfram, I was wrong about the DG Ravel cds - they are both Pierre Boulez! Excellent stuff, check it out! DM Quote Link to comment Share on other sites More sharing options...
Q-Man Posted September 22, 2004 Share Posted September 22, 2004 Wolfram, You could probably find a driver that would come close and sound somewhat better. Once you narrow it down to a driver that you think sounds better then it would most likely require network changes to make it right and better sounding. I guess that means no. It isn't easy to find a 250 Hz driver and horn, and that is what is needed for a 400Hz crossover point. Do you remember all the horns and drivers that I tried? Once I found the ones that made the most improvement then it took John to design and test a network for them. The network made another big improvement. That's why I think that I will be buying about another 6 drivers and horns to play with if I start this all over again. Be happy with the Corbeflex horn for now. It does do some things better then the 400 or 401. Improvement also comes by using a larger throat size then the Cobreflex and 400. Quote Link to comment Share on other sites More sharing options...
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