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105/3 Bass driver or crossover problem

 
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Ahenager
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Joined: 06 Jan 2015
Posts: 3
Location: Memphis, TN

PostPosted: Wed Jan 07, 2015 6:08 am    Post subject: 105/3 Bass driver or crossover problem Reply with quote

New member making my first post and I'm already asking for help! LOL

I recently lucked into ($100 USD) a set of 105/3 loudspeakers but I'm having issues with the bass drivers in both speakers. Both are "dead" sounding (very low output) and have a scratchy buzz. I know that the drivers were all re-foamed at one point but I can't tell if that's the problem or if it's an issue in the crossover. The top end of these speakers sounds incredible so I really want to pinpoint and fix this bass issue.

I have removed the h-m crossover panel and run signal to just the bass crossover to see if I can isolate the problem. On one speaker, if I touch the paper cone from the rear and apply very slight pressure the buzz goes away but the sound is still flat and dead. The bottom driver in the other speaker has a severe flutter and does not seem to move freely. I have not removed the driver assemblies from the enclosure to see if it's a problem with the physical installation of the section.

Any suggestions?
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Ahenager
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Joined: 06 Jan 2015
Posts: 3
Location: Memphis, TN

PostPosted: Wed Jan 07, 2015 7:37 am    Post subject: Update Reply with quote

I ran a full range signal to one of the drivers that was farting out. The speaker responded and played but was still buzzing. However when I applied slight pressure to the back of the cone as before, the buzz disappeared and I got a full signal from the speaker. Here's the kicker - I was able to produce this result ONLY when applying pressure to a certain spot on the cone (there are 3 openings so think 12 oclock) but if I moved my finger to 4 oclock or 8 oclock the buzz remained.
Does this suggest that the re-foam job might have been a bit off-center causing the driver to respond poorly?
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speakerguru
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Joined: 18 Nov 2005
Posts: 954
Location: Green Hut, Tovil

PostPosted: Wed Jan 07, 2015 6:36 pm    Post subject: Reply with quote

You'll only get to the bottom of the problem by completely dismantling the speakers and giving each woofer an individual good look over and a sine sweep. If touching gets rid of a buzz then it is definitely off-centre.
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Ahenager
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Joined: 06 Jan 2015
Posts: 3
Location: Memphis, TN

PostPosted: Thu Jan 08, 2015 3:03 am    Post subject: Reply with quote

Thanks for the help. Sounds like I know what I'm going to be doing tonight! lol
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proffski
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Joined: 22 Aug 2003
Posts: 1296
Location: Tewkesbury UK

PostPosted: Thu Jan 08, 2015 3:33 pm    Post subject: Reply with quote

Good luck and be careful!
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clubsport911
Senior Contributor 100+


Joined: 26 Aug 2012
Posts: 157
Location: Cheltenham, UK

PostPosted: Thu Mar 19, 2015 11:03 pm    Post subject: Reply with quote

This sounds like you need open heart speaker surgery. Relax.

Get to know your speakers, by carefully dismantling them (taking pictures and making notes along the way)

Everything about these great speakers can be fixed pretty easily, except the Uni-q driver and the 2 upper bass drivers. Be careful with those.

I suspect a dodgy voice coil. Forget who did what before... Get some new re-foam kits from oBEy and follow instruction but before doing all that, remove the units and check that voicecoil.

Once you have done the work (take your time, ask questions along the way) you will cherish them.

Sorry.... I do not see a quick fix here from what you describe.
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