mustang guy Posted February 1, 2014 Share Posted February 1, 2014 I've owned these LaScalas for a couple years, but until yesterday, I never actually listened to them while close together. What I found was that the bass notes are severely diminished. I actually had the LaScalas sides touching and parallel. The reason I bring this up is I always thought I would be getting gain in all channels. This is not at all true. It seems to me the cancellation starts at about 250hz. I have not tried stacking LaScalas, but I wonder if the same thing won't happen. I think it may have something to do with the shape of the horn. Can someone help to understand why this is happening? Quote Link to comment Share on other sites More sharing options...
Coytee Posted February 1, 2014 Share Posted February 1, 2014 I hate to ask an easy question but are they in correct phase? (Polarity???) I have a pair of mwm's and found more bass when I disconnected a unit....huh?? Seems one of the units had new drivers installed and was wired backward. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted February 1, 2014 Share Posted February 1, 2014 If the polarity is correct try stacking one on top of the other, with the top one upside down so the tweeters are close together. Quote Link to comment Share on other sites More sharing options...
LarryC Posted February 1, 2014 Share Posted February 1, 2014 I hate to ask an easy question but are they in correct phase? (Polarity?) That's the first thing I thought of, too. Putting a pair of speakers next to each other, and listening for loss of bass is a basic test for whether they are in phase. Your result suggests they're not. Quote Link to comment Share on other sites More sharing options...
Schu Posted February 1, 2014 Share Posted February 1, 2014 I've always wondered why a la scala/belle has less bass output and extension than a smaller Cornwall... I never understand that Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 Polarity could indeed be the cause. I was thinking it was comb filtering, but the whole bass frequency range was affected. That tells me the woofer alone is reverse polarity. Good thinking! As for stacking one on top of the other, I will try that some day when I have some help. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 1, 2014 Share Posted February 1, 2014 I've always wondered why a la scala/belle has less bass output and extension than a smaller Cornwall... I never understand that Horn vs ported direct radiator. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 1, 2014 Author Share Posted February 1, 2014 (edited) I've always wondered why a la scala/belle has less bass output and extension than a smaller Cornwall... I never understand that Horn vs ported direct radiator. shorthorn in a sealed enclosure. if the enclosure were ported and/or the horn length extended, then the lascala would produce a lower frequency. lots of people port lascalas, but so far as I know, nobody has tried to lengthen the horn at all. it would be a difficult task, and make the already massive ls even bigger. Edited February 1, 2014 by mustang guy Quote Link to comment Share on other sites More sharing options...
minermark Posted February 1, 2014 Share Posted February 1, 2014 Try running one or more of the audio testing youtube videos I posted just today. tells you a lot of what your speakers can reproduce. Also are you running original crossovers ? Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 2, 2014 Author Share Posted February 2, 2014 Try running one or more of the audio testing youtube videos I posted just today. tells you a lot of what your speakers can reproduce. Also are you running original crossovers ? recapped AL-3's. I bet I have the polarity reversed on one of the woofers. I replaced them in the spring of last year and probably got careless. There is plenty of bass extension (for LaScalas). The problem arose when I had them contiguous and in 2 channel mono. Also, it only happened to frequencies from the bass bin. Either speaker alone had great extension. Together and balanced, the bass tanked by something like -12db (guess) up to about 250hz (also guess). Quote Link to comment Share on other sites More sharing options...
minermark Posted February 2, 2014 Share Posted February 2, 2014 Try running one or more of the audio testing youtube videos I posted just today. tells you a lot of what your speakers can reproduce. Also are you running original crossovers ? recapped AL-3's. I bet I have the polarity reversed on one of the woofers. I replaced them in the spring of last year and probably got careless. There is plenty of bass extension (for LaScalas). The problem arose when I had them contiguous and in 2 channel mono. Also, it only happened to frequencies from the bass bin. Either speaker alone had great extension. Together and balanced, the bass tanked by something like -12db (guess) up to about 250hz (also guess). Reversed cap? we have all done this, some when I was a kid were packaged reversed, that was a learning experience. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted February 2, 2014 Author Share Posted February 2, 2014 Try running one or more of the audio testing youtube videos I posted just today. tells you a lot of what your speakers can reproduce. Also are you running original crossovers ? recapped AL-3's. I bet I have the polarity reversed on one of the woofers. I replaced them in the spring of last year and probably got careless. There is plenty of bass extension (for LaScalas). The problem arose when I had them contiguous and in 2 channel mono. Also, it only happened to frequencies from the bass bin. Either speaker alone had great extension. Together and balanced, the bass tanked by something like -12db (guess) up to about 250hz (also guess). Reversed cap? we have all done this, some when I was a kid were packaged reversed, that was a learning experience. Reversed wires on one of the woofers. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted February 2, 2014 Share Posted February 2, 2014 (edited) I've always wondered why a la scala/belle has less bass output and extension than a smaller Cornwall... I never understand that They don't. The Cornwall has less sensitivity. The top end of a Cornwall is throttled way back so that the woofer can actually keep pace. The Belle and La Scala have just as much output down there as the Cornwall, it's just that it's top end runs significantly hotter to match up with the bass bin horn above Fc. As frequency goes up, the horn response just sky rockets instead of staying flat like a direct radiator. The result is a response that apparently rolls off instead of extending, but the absolute measured SPL down at those frequencies is similar between cabs. You can derate a La Scala or Belle down to the Cornwall in sensitivity by shelving them. They'll end up sounding just as deep. "...from a certain point of view." Reversed wires on one of the woofers. Doh! How do they sound paired-up now? Edited February 2, 2014 by Quiet_Hollow Quote Link to comment Share on other sites More sharing options...
pzannucci Posted February 2, 2014 Share Posted February 2, 2014 I've always wondered why a la scala/belle has less bass output and extension than a smaller Cornwall... I never understand that They don't. The Cornwall has less sensitivity. The top end of a Cornwall is throttled way back so that the woofer can actually keep pace. The Belle and La Scala have just as much output down there as the Cornwall, it's just that it's top end runs significantly hotter to match up with the bass bin horn above Fc. As frequency goes up, the horn response just sky rockets instead of staying flat like a direct radiator. The result is a response that apparently rolls off instead of extending, but the absolute measured SPL down at those frequencies is similar between cabs. You can derate a La Scala or Belle down to the Cornwall in sensitivity by shelving them. They'll end up sounding just as deep. I'm not sure that is quite correct though close. The Cornwalls before the port kicks in, are close to the low bass (frequency wise where horn doesn't work anymore cause it's too small) that the LaScala can put out. Once the port takes over, the LaScala is still dropping though the Cornwall doesn't drop as low in output in the port tuning frequency (one of the reasons for the port loading), until you get past the tuning frequency, then the Cornwall really drops. Theoretically 24db per octave I believe. Quote Link to comment Share on other sites More sharing options...
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