SDA 2B left and right volume problem

danger boy

This is very odd.. but the left channel 2B is about 10 to 15% louder in volume than the right SDA.

little bit of background and why it's odd. i upgraded the tweeters to the RD0's. and replaced a bad MW6503 with a new replacement from Polk in the left SDA. now the left SDA is louder than the right one.

ok. you're saying, it's because the new MW6503 is new and it needs to break in.. maybe.. but that much of a difference? Plus, it seems that the left SDA with the new MW6503 stereo driver is SOMEHOW pulling volume from the right SDA thru the SDA cable?? weird i know.

I've changed amps, I've switched out sources, and i've changed out SDA's, the lower volume right channel 2B sounds just fine in volume when mated with a left channel SDA 2A for instance.

why is the left 2B drawing volume out of the right 2B? this is freaking me out.. my music all sounds very off.

any suggestions? I guess I can swap the new MW6503 driver from the left into the right SDA and see if it follows the driver in volume. Anyway.. they sound like horse dung right now..

I hooked up the 2A's. and beside the SL2000 tweeters in them, they sound freaking great and balanced in volume. so something odd is happening with my 2B's that just began when I moved the amp about 3 feet to a more permanent place. :mad:

shadowofnight

Could always throw on a test tone cd with the sound meter and see at what frequency it is louder at.....let you know if its the new tweeters somehow.

Also ohm out the new 6503 driver and make sure the correct voice coil is in there...compare it to the other channels pre-existing 6503...it could have gotten an incorrect voice coil and either be more efficient or less accounting for a db gain or loss between speakers ( Also moving the crossover point up/down depending on the voice coils ohm measurement ) .

You did do the tweeters and the new 6503 at the same time correct ?

danger boy

tweeters were done before the new MW6503 if that helps.

F1nut

Al, do as the man suggests, it's good advice.

shadowofnight

Thats actually good...you know its the 6503 causing the issue then....I did have one dual voice coil subwoofer driver come with mis-matched voice coils one time so it can happen. With the different versions of Polk 6.5" drivers out there, I wonder how many different voice coils they actually produced ? Hopefully my spanking new Compendium from Ray will have that info

danger boy

ok. i swapped the new MW6503 from the left SDA to the right SDA. problem fixed now sound is true and balanced again. very odd.. also when I moved the amp this weekend.. ever since then i've had to raise the volume from -36 to -32 to get the same volume I used to get.. now that is back to normal as well.

It could just be the new MW6503 is just that new.. and it puts out more volume than the 20 yr old one. or a crossover part could be going bad. either way.. things are back to normal now.

I guess I just rack it up to gremlins in them for now.
thanks, but since i'm a electronics ****.. i can't measure the ohm level output.

shadowofnight

All that matters is that you are again happy with them....enjoy

danger boy

shadowofnight wrote: »

Could always throw on a test tone cd with the sound meter and see at what frequency it is louder at.....let you know if its the new tweeters somehow.

Also ohm out the new 6503 driver and make sure the correct voice coil is in there...compare it to the other channels pre-existing 6503...it could have gotten an incorrect voice coil and either be more efficient or less accounting for a db gain or loss between speakers ( Also moving the crossover point up/down depending on the voice coils ohm measurement ) .

You did do the tweeters and the new 6503 at the same time correct ?

where could I get a CD with a constant tone on it?

shadowofnight

This one if you want a GUI interface ( DVD based...visual implementation ) I will look where I got my REALLY good cd based tones from later....
http://www.avsforum.com/avs-vb/showthread.php?t=742969

This DVD is killer for home theatre adjusting as well....

shadowofnight

From 10Hz to 1KHz mp3's here along with some full frequency sweeps here...

http://www.snapbug.ws/sinewaves/

http://mdf1.tripod.com/test-tones.html

There are tons of them out there...type test tones as your search in google...I have made like 6 or 7 cd's over the years...some are mp3's...some wav's ...etc Find some that are individual ( Not sweeps ) all the way across the spectrum.

My main uses in the past have been the extreme lower frequency ones ( 5Hz...to 10Hz mainly ) for breaking in subwoofer drivers without driving everybody batty It works the spiders and surrounds very well ...just be careful...and watch your excursion as those frequencies arent audible . The very first time you run a 5Hz signal and SEE your sub go to its X-Max and you dont hear it...is very cool

Then there is the 15Hz to about 100Hz....awesome for checking room resonances ( And in ported speakers port huffing...main reason I went to the newer high capacity passive radiators ) ...you will not believe what vibrates and causes noise....I worked for days silencing all the rooms in my house...from simple thick felt under the lamp shades to rtving down a shower spout cover in the hallway bathroom that was loud as hell with deep bass. Also killer for seeing just how low your sub goes before its -3db point ( With the trusty tripod mounted sound meter )

Above 100Hz is probably where you would benefit most from with your 6503 issue ( Well when you HAD the problem...you said swapping took care of it...which was strange )....using the balance knob...isolate the left channel and make a plot of near field measurements...db levels at all frequencies...the go right and do the same ...see where they differentiate.

As you can probably tell building/testing speakers ( And amplifiers...love power makers ) is the highlight of my audio hobby

In my new house it took at least 3 days for me to get my home theatre dead silent...but at least I know when I hear something in a movie...its not the room.

danger boy

more info on this.. tonight. the right ch SDA 2B was DEAD. DEADDDD except for the slightest volume from the RD0 tweeter. I dropped a heavy book on the floor near the right speaker and it came back to life.. meaning something is bad or loose.

turned everything off.. back on again, same problem. I removed the grill from the right speaker and touched the surround with pressure on the SDA driver.. and it came back to life..

does this mean that driver is going bad.. or is there a possible crossover problem in that speaker? today is the first time it's cut out completely like that.

once the SDA driver comes back on at full volume it sounds just fine..

danger boy

Houston we have a problem.

turned on the 2 ch SDA2B rig this morn.. no audio from the right SDA, ugh. dead.

wiggled the binding posts and it pops in.. then I smell a burning smell.. not good.

turn everything off... now i'm afraid to turn it back on.. sounds like a loose wire in the binding posts or crossover in the right channel.

[Deleted User]

Hello,
It is probably a good idea to examine the inside of your speaker. Probably the easiest way to do that is to remove the grille cover and remove the passive radiator. This should give you the best view of the speaker's inside, you can remove the internal damping material and use a flashlight to take a look inside. Let us know what you find inside.
Regards, Ken

shadowofnight

Oh Oh ....the smoke is never good....and its really hard to get that smoke back in where it came from Pull that sucker apart and take some pics.....

danger boy

Kenneth Swauger wrote: »

Hello,
It is probably a good idea to examine the inside of your speaker. Probably the easiest way to do that is to remove the grille cover and remove the passive radiator. This should give you the best view of the speaker's inside, you can remove the internal damping material and use a flashlight to take a look inside. Let us know what you find inside.
Regards, Ken

will do that tonight.

shadowofnight, no smoke, just a burning smell. luckily i didn't have the volume turned up...or it could have been fatal. :eek:

danger boy

well, good news.. the SDA 2B's are fine.. no fried parts to those.. but for some odd reason, this Pioneer Elite int amp I've been using for the past three weeks on them.. suddenly is now having a problem running them at any volume.

if it wasn't a common ground amp, don't you think it would have had a problem running them right away or at least show some signs of trouble? Three weeks later it seems the amp is shorting out with the SDA's. I'll take the amp in for service this week and see if they can find out what's up.

very odd that this is happening now. But as well all old used gear, sometimes bugs pop up over time. I'm going to try and lessen the load with a pair of Monitor 7's and see what the results are there. I've also just bought new speaker wire. and will replace both runs with 14 guage new wire in case that is the culprit.