Dual 1218 shakes right 12" low freq loudspeaker more than left

Finnetric

New Member
I am truly honored to be on AK, but I am a novice. I may describe something incorrectly by totally botching a technical term, so my apologies in advance. I have found that this site has provided endless amounts of wisdom and has been so much fun for me. I highly respect the opinions and feedback I receive from members.

Here we go...

When I drop the needle on my Dual 1218 TT, the right channel 12" low frequency loudspeaker (I've been trolled for calling it a woofer) on my JBL L100As shakes way more than the left.

I've ruled out loudspeaker movement inconsistencies with other component inputs, ie FM and iPhone input through the receiver (Marantz 2270), but for whatever reason the issue only occurs with the TT. With other components, each 12" loudspeaker is synchronous and the sonics the same from each speaker.

I've explored a few TT options to help resolve as well, but the issue with the right woofer (OK, so I went there) still persists. I've adjusted the anti-skate. Double checked the cart alignment, double checked the polarity of the RCA cables running from the TT to the receiver, and different records. Still more bounce to the once on the right woofer.

Thanks for any direction/help you can provide.
 
Needle / cartridge issue? Internal issue with the table (bad/out of spec resistor/cap/etc)? Sorry, don't know turntables.
 
Most likely that speaker is too close (less isolated) to the TT.

Yes, move things around physically. Also swap cables from left to right on turntable and/or speaker. Swap the speakers themselves from left to right. If it doesn't change sides it pretty much can only be the proximity to the turntable.

And woofer is fine with us. :)
 
Agreed with Montycat, this is an acoustic coupling problem to solve. You've likely got the turntable placed where the lobe of the woofer's output is large. Move around the room to find where those exist - you'll hear/feel the bass levels go up. You want the turntable where the intensity is lowest.

Note from my past: The lobes will _not_ cooperate with where you want to put the turntable!

Cheers,

David
 
Needle / cartridge issue? Internal issue with the table (bad/out of spec resistor/cap/etc)? Sorry, don't know turntables.
I've swapped out the JBLs for Dyanco A35s, but there's not an issue with the woofers on the Dynacos:dunno:
 
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Agreed with Montycat, this is an acoustic coupling problem to solve. You've likely got the turntable placed where the lobe of the woofer's output is large. Move around the room to find where those exist - you'll hear/feel the bass levels go up. You want the turntable where the intensity is lowest.

Note from my past: The lobes will _not_ cooperate with where you want to put the turntable!

Cheers,

David
Thanks, David. I'll reorder the chairs on the Titanic:)
 
Needle / cartridge issue? Internal issue with the table (bad/out of spec resistor/cap/etc)? Sorry, don't know turntables.
TT was just restored and worked perfectly with my Dyanco A35s. Just the issue with the JBLs I'm afraid. They (JBLs) don't like this old machine...
 
I've swapped out the JBLs for Dyanco A35s, but there's not an issue with the woofers on the Dynacos:dunno:
Swap both sets of the positive and negative wires on both speakers and see if the problem appears again. By doing this, you can change polarity of the speakers relative to the turntable.

Think of it as an acoustic feedback mechanism where you can control the positive or negative feedback loop.

Hope that makes sense!

Cheers,

David
 
RESOLVED! I isolated the feet of the TT and the speaker cabs, which I believe was the major issue. I also moved the receiver out from within the entertainment cabinet and placed it on the top. Last, I placed the TT on top of the receiver, which added a bit more isolation, I assume.

Thanks for everybody’s suggestions!

-Eric
 
Probably shouldn't have the turntable (or anything else) on top of the receiver. Usually not a good idea to block vents and such.
 
Probably shouldn't have the turntable (or anything else) on top of the receiver. Usually not a good idea to block vents and such.
I’m going to move the TT to a isolation shelve on the wall. This was only a temporary solution to rule out low frequency feedback from the JBLs. Thanks for your suggestions!
 
  • Glad you solved it. I have set of JBL 100s tied to a Marantz 4270. Have a 2270 being rebuilt. Running a 1229 and a 1010S. Great sounding combination. You have a nice combination.
Eric from Kingston NY
 
  • Glad you solved it. I have set of JBL 100s tied to a Marantz 4270. Have a 2270 being rebuilt. Running a 1229 and a 1010S. Great sounding combination. You have a nice combination.
Eric from Kingston NY
Thanks! I'm having a Marantz 4400 restored by AKer legend @wlhd1610 currently and will eventually pair it to the JBL L100As (Late). The 2270 will then be paired with the Dynaco A35s, which sound AMAZING. I have to upgrade my living situation to handle all my vintage HiFi gear, ha! Your quad 4270 pairing with the L100s must sound spectacular! The 1229 is a great TT as well
 
Wow, a 4400! A beast! Nice. That's a true collectors item! Marantz is going up. The Marantz tax. Not sure where I will put the 2270. The 4270 lives in the livingroom. Sounds great there but it's not my main listening room. My daily driver is in my bedroom as shown in my avatar. Have had many receivers there. Being old I remember model numbers from the 70s. My 2270 dropped a channel. Had a 2245 in its place. Basically it's very similar inside to a 2270. Found a Sanyo built Fisher 301 Quad. Had one briefly in college with Fisher speakers. Not a great combination. Sold it after 6 months. Got this 301 off Eprey for $96 shipped. Nostalga. Have had different speakers in the bedroom. Traded ADS 810 for a pr of JBL Decade 26s. Did not like them in the 70s paired a Kenwood 7100. This time I like the JBLs. They sound great with the Marantz receivers. The Fisher sounds great too. May keep it there for now. It's a sleeper! The seller lost $ on this receiver! Only issue is the FM section isn't great. Hooked a Pioneer TX 500 tuner to it. I have one station I listen to and the Fisher doesn't pull a NPR clearly. All the stations I don't listen to are Ok. The $26 Pioneer works fine. Have a cool Dual 1219 with the German base and cover on top. End the day with a record!

Have not heard the Dynaco A35s. Have a pr of mint A25 though. Live on the Mrs system in the dining room. Good sound there.

Enjoy, Eric from Kingston
 
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