momo's overdriven?

sirogenous

I am having an issue concerning my 6 1/2" momo's sustaining damage to the voicecoil. Polk has already replaced one of the 6 1/2" drivers by covering it under their 3 year warranty. However, the other original momo has also begun to exhibit the unmistakable sound of a speaker that has sustained damage to it's voicecoil. I have always been careful not to drive my amp into clipping. Nor, do I listen to my music with more then 1 or 2 db added to the original low bass signals. The manufacture of the amplifier I drive my system with gives a claimed continuous RMS 4 ohm rating of 100 watts per channel. They also claim it's maximum output into a 4 ohm load is 230 watts per. ch. The manufacture also gives other claims such as 1 and 2 ohm specs. and 1 and 2 channel operation as well as specs when the unit is in "high current mode" or "high voltage mode". The amp uses only a single 30 amp fuse for protection so a max output of 230 watts per channel, two channels driven, is questionable. I guess the question I am asking the forum is howcome my 250 watt, 130 watt con. Momo's bass drivers seem to be getting damaged? I had thought about harmonics created within my amp doing the damage. However, usually that requires putting the amp into clipping. Something I am careful not to do. I have always thought that damage to the tweeters would occur and reveal itself before damaging the drivers should an amp begin to introduce unwanted harmonics into the output signal.

dohcmark8

It would help if we had the make and model of your amplifier, and also how are your gains on the amp set?

Dennis Gardner

Full range or filtered?

1996blackmax

Knowing the amplifier that you have would help, as well as the HU's settings (wether or not you have either the loudness or processing on the HU engaged), crossover settings if any, , and if you have the bass boost engaged on the amp.

sirogenous

I apologize for taking as long as I have in getting back to your responses.
The speakers are being filtered via my amplfiers HPF and set @ 50 Hz. My HU also has several HPF settings. However, it's lowest freq. setting is 68 Hz. Using the HU lowest setting I feel too much is lost of the bass freq. since I only am using momo's to speaker my system. Sound is adjustable via the HU 7band EQ. @ 62 Hz, 157 Hz, 396 Hz, 1.0 KHz, 2.5 KHz, 6.3 KHz, 16 KHz. I listen to most music @ 62 Hz thru 396 Hz @ 0 dB. 1.0 KHz @ -1 dB, 2.5 KHz @ 0 dB, and 6.3 KHz @ -3 dB and 16 KHz @ -4 dB. The HU also has what Sony calls their DSO or Dynamic Sound Stage Organizer, but I never use it due to using the HU front speaker line output only. I listen to rock music as well as classical and never do I boost the bass freq.
Amp....Sony XM-1002 HX 1 ohm selectable...high voltage mode/high current mode...set at high voltage mode. 40 Hz bass boost...set @ off. HPF 50Hz to 200Hz set at 50Hz @ 12 dB cutoff.

HU...Sony CDX C8050X ES

Speakers...Polk MoMo's 6.5 components

MacLeod

That amp isnt powerful enough to overdrive your speakers unless youre clipping it.

I ran my Momo components with about 140 RMS for years and never had a problem.

My first guess could be the gain setting. If you have this set to high, its possible youre clipping the amp and that is overheating and eventually damaging the voice coils.

Another possiblity is that you just got a defective set of speakers. Polk has great QC but being one of the largest manufacturers in the world, every once in a while a lemon will sneak thru.

And yet another possibility is that theyre refurbs. If you bought them off of Ebay or an unauthorized dealer there is a good chance theyre remanufactured, repaired or whatever.

sirogenous

Thank you for replying once more MacLeod.
Funny that you mention refurbs...The MoMo that I wish replaced happens to be the replacement that was given to me when I visted Polk's customer care offices here in San Diego. I was handed a speaker and was asked to sign a release stating that the speaker was new. I was shown the plastic bag I was told it was packaged in but I have no way of telling a difference between new and renewed, bagged or unbagged. I certainly am not making any accusations towards any intentional wrong doing whatsoever by any means. I just wonder if by mistake someone could have grabbed from the wrong box possibly. Heck...does Polk even remanufacture damaged speakers? I mean...why would they bother. Not like there is any money to be made from all those Polk speakers out there that will be in need of repair at one time or another for crying out loud. LOL Considering I still listen to my music at home via a pair of Polk monitors that my late dad purchased new for $540 bucks each back in 1978. I even have the receipt and owners manual. Nearly 30 years old and still they impress!

danger boy

are you sure you didn't get "white vanned"? sorry. i know it's not funny. but it sounded like a white van story to me.

good luck

MacLeod

If you got it from Polk and they said it is new, then you can trust that it is new.

Ive been dealing with Polk for a few years now and have even met some of the staff and and trust me when I tell ya, theyd take a loss before theyd screw you over.