My Monitos 7B Have a Problem With...

Freak When C

My Monitor 7B's Have a Problem With Bass Response.

In my Other 7B thread (in Post # 57) I described hearing flabby sounding bass. Well, when listening to the CD "DIVA" by Annie Lennox, (track #10) "The Gift" I was able to reproduce that distorted flabby bass sound. I removed the grills and it appears that the drivers seem to get "extended" movement when this distortion occurs. Almost like they're going to to pop outwards from the cabinets. I was like wow, and turned down the volume.

Does it sound like my drivers are going or would this issue be more related to the radiators?

In page one of my other thread the following info was posted:

kcoc321 wrote: »

driver needs to be replaced and it will cost $20-$30min for the 'used' MW6502 (Look in the "for sale" section area).

New replacement ones (MW6503's) are available from Polk for $48ea with Club discount, only you would want to replace both.

I would also definitely pull the "correct" MW driver and check to make sure it is right.

Think I should buy new drivers from Polk?

F1nut

What are you driving them with and at what volume level is this happening?

Freak When C

Driving them with a Parasound Zamp v.3. I can also sometime hear bass distortion on certain songs when playing my tuner. It has to be a really heavy bass kind of song though. The Annie Lennox song "The Gift" is one such song and thus, it definitely allows me to reproduce the bass distortion issue. I had it turned up at a pretty good volume but not like ear splitting levels. It wasn't distorted except for the bass and when it does, man do those drivers ever have some extended movement.

vc69

I wonder if the radiator is adjustable and wacked out. Or if your amp is overworked. Those 7's like power and don't get just real loud. I dunno? Somebody here will though.

Freak When C

The drivers are what's having the extended movement. I turned down the volume and all is fine. The drivers still work. But they don't work very well when I want to turn up the music on a song like "The Gift" that has very deep heavy bass and drums. I'm asking if this sounds like a problem with my drivers or could it be something else? I did get these off CraigsList and they're 28 yrs old. So perhaps the drivers are going?

Ya know, in that other thread I linked to, other members suggested I redo my crossovers. Would faulty caps in my crossover be causing these symptoms? I don't want to buy new drivers unless I know that's what needs replaced. Of course if I keep making the drivers distort they're gona need replacing for sure.

Freak When C

Yes, the CD is being played through my Lexicon universal player. The Lexicon has two sets of "front" output jacks as well as side and rear output jacks (all active all the time). I have one set of front outputs from the Lexicon connected to my Z series Parasound gear, the other set going into my Parasound Classic 2100 preamp with HT bypass that's integrated with my HT setup. So what I can do is disconnect my front monitors from my 5-channel amp in the HT setup and connect the Polk 7B's, then test again.

I'm gona wait until tomorrow though, its 10:00 pm and kinda don't want to crank the jams. I'll check back in tomorrow with the results. Hoping its actually not my amp. Thanks for the help guys.

AudioGenics

for your information...
if you decide to replace the driver

I have one original MW6502 available.
New Old Stock
unused excellent condition

kcoc321

It is definitely asking alot of that little amp if you are pushing it. @ 45wpc you need to take it easy. If you got to the point of distending the MW's you are pushing it way too hard. Do as Las said and try it with another source.

F1nut

It's the amp. As kcoc321 stated, you're asking far too much from far too little power. Turn it down or buy a bigger amp. Do not waste money on replacing the drivers.