Thrift Store Score 1988 5JR+ lack of bass

nwlierly

I found these at Sally Ann's, opened them up last night to confirm production year.

Some of the discussion threads around them indicate that replacing the crossovers should be step 1 in refurbishment, I think that would follow with the symptoms I'm seeing.

I've hooked them up to three different heads, a Pioneer VSX-D409, Harmon Kardon HK 3270, and a Yamaha RX-360. All three should have more than sufficient power to drive them but all three fail to provide much low end at all. Until I confirmed the series I thought I was dealing with a resistance mismatch issue.

I also need to find some replacement grills, but that's secondary...

pitdogg2

check for air leaks. push in on the passive radiator and see if the mid stays out for like 3-4 seconds if it does not then you have air leaks and that will affect bass response.

codycatalist

I agree with @pitdogg2 also remove the PR and make sure the Dacron is shoved behind the mid driver. It should NOT be down behind the PR.

My Monitor 5s (Granted mine have an 8 inch passive not a 6.5) have low end but you can only ask so much from a Monitor.

nwlierly

I don't think I was clear enough about how severe it is, it's like they're not getting a quarter of the power they need - they appear to by physically intact, but I'll double check

dkfreebird

Have you checked the mids to see if they are siezed?

pitdogg2

dkfreebird wrote: »

Have you checked the mids to see if they are siezed?

this^^^^ push them in carefully and see if the move freely with no scrapping magnet shift is common.

codycatalist

Yeah I agree with @dkfreebird as well. If it is THAT severe then I would figure either the driver is seized or some of the cross over components are fried.

nwlierly

I'll check again, but they didn't show any signs of it

nwlierly

hmm mids could very well be frozen, mid doesn't want to do a thing until volume is near max...

Nightfall

Physically press the midwoofers, gently and evenly, with your finger tips.

nwlierly

magnets are out of alignment uggggfgggfffggfdbdbbdbd

nwlierly

so glad to hear someone will save me from guess work


I managed to just about double output with a quick adjustment, but it's clearly not close to right based on ability to move the speaker freely

lawdogg

Thanks @la2vegas Yeah I can re-center and glue the magnet in place if you like. I offer a free re-centering service to help out Club Polk members who fall victim to magnet shift. Wrapping up some 6501s right now so you're welcome to send them my way for re-centering or to trade out of my current stock of re-centered drivers. Shoot me a PM!