-Russian-Spy- Posted November 22, 2019 Share Posted November 22, 2019 So i'm having some issues with my la scala's bass response. One cabinet has a significant difference in bass response, one cabinet has pretty clean punchy bass, and the other... Well not so much. I am getting sound from the woofer, but it seems pretty thin with a significant drop in percieved volume (the bass does not sound full), maybe 6db. Does this sound like a sealing issue? Any thoughts? Quote Link to comment Share on other sites More sharing options...
MechEngVic Posted November 22, 2019 Share Posted November 22, 2019 Did it just start doing it, did you notice a gradual loss of sound, or has it always been that way? Is there any rattling at volume? It could be sealing, woofer damage to cone, surround or coil, loose mount, crossover failure. Did you try switching channels of wires between amp and speakers to eliminate amp issue? Sounds like you're gonna have to break into that cabinet. Quote Link to comment Share on other sites More sharing options...
-Russian-Spy- Posted November 22, 2019 Author Share Posted November 22, 2019 37 minutes ago, MechEngVic said: Did it just start doing it, did you notice a gradual loss of sound, or has it always been that way? Is there any rattling at volume? It could be sealing, woofer damage to cone, surround or coil, loose mount, crossover failure. Did you try switching channels of wires between amp and speakers to eliminate amp issue? Sounds like you're gonna have to break into that cabinet. They are recently acquired, i purchased them a month or two back. The crossovers are new crites a/4500's, and i did investigate possible amp/channel issues, and it is related to the cabinet. I assumed id have to open them up and investigate, but i could use some direction with type of sealant to use. Is there a sealant i can get from the hardware store? Or would parts express/other online vendor really be the only way to go? Quote Link to comment Share on other sites More sharing options...
garyrc Posted November 22, 2019 Share Posted November 22, 2019 Different locations in the room produce different bass characteristics. Put your right speaker where the left one is now, and vice versa, and see if the bass problem follows the bass-shy speaker. If it does, it may be the speaker. If it doesn't it may be the room's "boundary gain." Paul Klipsch recommended putting La Scalas in corners for maximum boundary gain. If a La Scala is out in the room (where some "audiophiles" put their speakers), away from any walls, and is moved to a position against a wall, actually almost touching the wall, a gain of about 3 dB, mostly in the bass, should happen. If it is then moved into a corner, almost touching, you should get another 3 dB or so. So that's a total increase of 6 dB, mostly in the bass. Since the power demand in music is often greatest in the bass (even if you use a sub below about 80 Hz, there is plenty of bass power needed between 80 Hz and 160 Hz where the leading edge of bass attacks occur) the boundary gain is useful, and as PWK said, it is like exchanging a 100 watt amplifier for a 400 watt amplifier, without extra strain on the speaker. Quote Link to comment Share on other sites More sharing options...
glens Posted November 22, 2019 Share Posted November 22, 2019 Next easiest check is swap the crossovers. After that, if needed, I'd play some gradual tone sweeps and check for rattling, buzzing, huffing, chuffing, etc. Beyond that comes opening to check wire terminations / connections and measure the resistance of the voice coil, both directly and through the wiring. . Your nearby homecenter will have some foam weather seal or such if you think the hatch cover needs it when you eventually go back together. Quote Link to comment Share on other sites More sharing options...
MechEngVic Posted November 22, 2019 Share Posted November 22, 2019 There is no sealant, just the gasket that is mounted on the woofer. If there is a problem with the seal, it's usually the woofer coming loose. Over time the loose woofer can damage the gasket. Quote Link to comment Share on other sites More sharing options...
innerwestsoul Posted November 22, 2019 Share Posted November 22, 2019 FWIW getting access to the bass section is super easy. On the basis that your crossovers are well attached in place, simply flip the speaker upside down and unscrew the base. It’s worth a look in there anyway, if only to admire the big ol driver! Quote Link to comment Share on other sites More sharing options...
DizRotus Posted November 22, 2019 Share Posted November 22, 2019 Are they in phase? Before opening the bass bin I’d confirm all connections at the crossovers. I’d also try the suggestions above regarding swapping networks side to side, as well as swapping the speakers side to side, changing one variable at a time. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 22, 2019 Share Posted November 22, 2019 4 hours ago, DizRotus said: Are they in phase? Before opening the bass bin I’d confirm all connections at the crossovers. I’d also try the suggestions above regarding swapping networks side to side, as well as swapping the speakers side to side, changing one variable at a time. I would think that one speaker out of phase would cause an overall lack of bass, not diminished bass from just one speaker. 1 Quote Link to comment Share on other sites More sharing options...
jason str Posted November 22, 2019 Share Posted November 22, 2019 The bass bin gasket material may have turned to a sticky mush by now, scrape off the old and get yourself some new stuff such as this. Overlap the ends and slice both even, remove the excess material and but the ends up. Quote Link to comment Share on other sites More sharing options...
JohnA Posted November 22, 2019 Share Posted November 22, 2019 Yeah, make sure both have either K-33-Es or K-43s, and both are the same. Listen for scraping/scratching as ONE way to determine if you have a damaged woofer. Quote Link to comment Share on other sites More sharing options...
-Russian-Spy- Posted November 22, 2019 Author Share Posted November 22, 2019 4 hours ago, jason str said: The bass bin gasket material may have turned to a sticky mush by now, scrape off the old and get yourself some new stuff such as this. Overlap the ends and slice both even, remove the excess material and but the ends up. Welp, i opened up the hatch, and the cover was not secured very well, most of the screws were not very tight at all. The gasket is definitely mush, there is deteriorated gasket material on the hatch and cabinet. Will report back soon. I would post some pictures, but i keep getting an error "-200" 1 Quote Link to comment Share on other sites More sharing options...
MEH Synergy Posted November 22, 2019 Share Posted November 22, 2019 Glad you MAY have found the culprit... Russian spy eh....? Hmmmm M. Mmm... Hmhmmmgmhmhmhmhmhhgmg..... Hmhmhmhm Quote Link to comment Share on other sites More sharing options...
jason str Posted November 22, 2019 Share Posted November 22, 2019 28 minutes ago, -Russian-Spy- said: Welp, i opened up the hatch, and the cover was not secured very well, most of the screws were not very tight at all. The gasket is definitely mush, there is deteriorated gasket material on the hatch and cabinet. Will report back soon. I would post some pictures, but i keep getting an error "-200" My apologies, that was my routine on round installs though you could 45 deg. the corners in that fashion with a square. Just make sure you cut the tape tight and straight at the seam so there no chance of a leak. Follow John's instructions and check wiring while you're in there. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted November 23, 2019 Share Posted November 23, 2019 46 minutes ago, jason str said: My apologies, that was my routine on round installs though you could 45 deg. the corners in that fashion with a square. Just make sure you cut the tape tight and straight at the seam so there no chance of a leak. Follow John's instructions and check wiring while you're in there. ALSO, check the machine screws holding the woofer to its motor-board...tighten as necessary! I tend to get them all snug, then, one at a time remove each machine screw, add a lock washer and a flat washer to it, then replace it. This is why: Over time the plywood of the motor-board will actually shrink some in its THICKNESS...but with the addition of a flat washer up against the woofer frame, and then a standard lock-washer between the flat washer and the machine screw head, you will be good to go for defeating this from happening again in the future. Another thing is to be careful when replacing the woofer access panel....with the speaker upside down on a soft surface, apply pressure with one hand to the CENTER of that door panel, while tightening ALL of the screws to where they are SNUG, FIRST...then one at a time, while still applying pressure to the center of the panel, finish tightening the screws...but be VERY CAREFUL to NOT over-tighten them so that the screw-heads sink DEEPER into the wood panel, and especially not to let the point of those screws go thru the bass bin bottom panel so that their points are sticking up into the bass bin, itself. Also, if you over-tighten those wood screws, they may strip-out enough wood so that you will have to make a "wooden match-stick and glue" repair to the holes the screws were in, so that they can get a "new grip" there. By all means, use a hand-screwdriver for this and NOT A POWERED SCREW-GUN or DRILL! TRUST ME! 2 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 23, 2019 Share Posted November 23, 2019 11 hours ago, -Russian-Spy- said: Welp, i opened up the hatch, and the cover was not secured very well, most of the screws were not very tight at all. The gasket is definitely mush, there is deteriorated gasket material on the hatch and cabinet. Will report back soon. I would post some pictures, but i keep getting an error "-200" Try resizing your pictures smaller. Quote Link to comment Share on other sites More sharing options...
ricktate Posted November 23, 2019 Share Posted November 23, 2019 If you have not done this yet I would loosen and re-tighten all connections on crossover. You can use just about any sealing foam...parts express shipping is crazy if you dont order a lot. I also got these for my K-horns when I rebuilt the crossovers. https://www.parts-express.com/erse-super-q-25mh-16-awg-500w-inductor-crossover-coil--266-908 Quote Link to comment Share on other sites More sharing options...
-Russian-Spy- Posted November 23, 2019 Author Share Posted November 23, 2019 6 hours ago, CECAA850 said: Try resizing your pictures smaller. Smaller than 1.2mb? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 23, 2019 Share Posted November 23, 2019 3 hours ago, -Russian-Spy- said: Smaller than 1.2mb? Normally you're ok under 2. Quote Link to comment Share on other sites More sharing options...
-Russian-Spy- Posted November 26, 2019 Author Share Posted November 26, 2019 Some pictures of the gasket... Both gaskets were extremely deteriorated and missing some pieces. Replaced gaskets and put everything back together, performance of both bins have improved. Thanks for the help everybody. Quote Link to comment Share on other sites More sharing options...
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