Bad Capacitors? (1 Viewer)

[Mike Up]

I've had my Infinity RS1 (previous model year RS 2000.1) bookshelf speakers a long time. They sound smooth, detailed, dynamic, revealing, but also sound reverberant, and very attentuated in the vocal chestiness range while upper end vocals dominate. This making for a very un-natural sounding speaker. Never noticed this before until I recently got the Polk Blackstone TL1600 speakers system. I couldn't believe how much better these Polks sounded than the bigger Infinity speakers, much more lifelike and realistic. I then replaced my Infinity Reference speakers, the RS1s and CC-2, with Polk TSI100s and CS10 and the sound is SO MUCH BETTER. My wife who hated the Infinity Reference RS1 and CC-2 speakers, would rather listen to the TV speakers because they were easier to understand voices. Now that I have the Polk TSI100s and CS10s, she really likes to listen to them as they make voices so much easier to hear.

The Polk Blackstone TL1600 and Polk TSI speakers share a very similar voice and sound very much a like where the bigger speaker are more open and spacious.

My question is that I've read that dried up capacitors in the crossover network make the speakers more chesty, more muddy and with less treble. My Infinity speakers seem to sound the opposite. Is it possible the capacitors could be bad, or has my speaker voicing likes just changed over the years.

My Infinity RS1 and CC-2 speakers were purchased around 1997.

Thanks.

 

[JohnRice]

A lot of stuff can go wrong with old speakers. The surrounds can dry out, the crossovers can go bad and of course the voice coils can get fried from being fed a distorted signal.

It's certainly possible, even common for 20+ year old caps to go bad. At the same time, I have even older speakers and they are still singing, so it's not an automatic. It certainly sounds like something is wrong with them, but I'm not certain anything specific is indicated from what you say.

 

[BobO'Link]

John mentioning "20+" year old caps means, if possible, look at the caps in your speakers. If they're electrolytic type that are bulging and/or leaking that's absolutely an issue.

This image shows leaking and bulging electrolytic capacitors - they're in the process of failing.

A good capacitor of this variety should have a flat top:

 

[jcroy]

Around y2k or so, there was a case of bad capacitors due to corporate/industrial espionage. It turned out they got the stolen formula wrong, which cause such capactors to fail prematurely.

How a stolen capacitor formula ended up costing Dell $300m

Though the American company had nothing to do with the industrial espionage in China in 2002 that led to faulty components, it paid the price with millions of faulty PCs

www.theguardian.com

 

[jcroy]

Capacitor plague - Wikipedia

en.wikipedia.org

 

[JohnRice]

Often the crossover is on the back of the plate with the amp connections. It can be as easy as removing it carefully to look at the caps.

 

[Mike Up]

Thanks everyone. I work on Electronics but the caps can dry out without bulging. Just wanted to know if the sound I'm hearing is the speakers characteristics or the caps failing. The caps aren't bulging but I intend to get rid of these and I don't want to butcher them up if not need be. I want them to have the factory look UNLESS I need to put new caps in them.

Not a big deal to solder in a 6 caps if I need to but as I said, I want them to look factory if I can. Also, If I do put the caps in, I would want to make sure it makes a difference and I'm not just wasting my time when it's the speakers characteristic.



Thanks for the help.

 

[Mike Up]

Around y2k or so, there was a case of bad capacitors due to corporate/industrial espionage. It turned out they got the stolen formula wrong, which cause such capactors to fail prematurely.

How a stolen capacitor formula ended up costing Dell $300m

Though the American company had nothing to do with the industrial espionage in China in 2002 that led to faulty components, it paid the price with millions of faulty PCs

www.theguardian.com

Thanks for the heads up.

I had to replace many caps on some older Dell Process computers back from around early 2000s. Surprisingly not to many HP computers had the issue, just with the Dell computers.

 

[Mike Up]

The more I think about it, the speakers probably need caps. The reverberant sound I was hearing is likely the tweeter and woofer playing the same frequencies but out of time or alignment due to the capacitors. This causing a reverberance.

I had the same problem but to a greater degree also with some frequency gaps in the tower 2000.4 I had. The 2000.4s cabinet cloth was all shredded and they were tipsy and fell a few times so I thought it was just time to rid myself of them. The voicing I heard is probably their natural characteristic that I liked when I was younger due to upper midrange emphasis due to the more detail. Cheaper speakers of the day, where muddy and very chesty sounding so this may have been a more desirable characteristic for me. It's been over 20 years so I can't remember what I thought back then.

I did find with my JBL headphones that I could mimic their tonal quality by adjusting the equalizer in my Samsung Galaxy phone. I found that when I took 125Hz, 250Hz, 500Hz, and 1Khz down to -4 db, everything else being at 0 db, the JBL Headphones on the Samsung phone sounded alot like my Infinity RS1 and for the matter even the 2000.4s.

So I guess tonally the Infinity RS1 could be said to be accurate but with a deficiency in the lower midrange and midrange frequencies. Having lower output in the midrange and lower midrange, they didn't have a life like tonal characteristic that I found in the Polk speakers I have now (TSI100 and TL1s).

Stinks that these capacitors go bad on 20 year old speakers that aren't played constantly or continuously, or with much current, and with such low voltage.

Guess I'll be putting caps in my Infinity Entra .5s in 5 years or so. They do sound pretty good so I don't think they need them yet. The Infinity Primus P143s are only about 7 years old.

I'll likely donate the speaker to salvation army where someone can put the capacitors in if they want. Pricing out the caps and what I was going to sell the speakers for, I wouldn't be getting much for the speakers along with the time and effort selling the speakers along with the time and effort with putting in the caps.

I got those speakers all for 50% off of list so I definitely got my money's worth out of them.

 

[jcroy]

I had the same problem but to a greater degree also with some frequency gaps in the tower 2000.4 I had. The 2000.4s cabinet cloth was all shredded and they were tipsy and fell a few times so I thought it was just time to rid myself of them. The voicing I heard is probably their natural characteristic that I liked when I was younger due to upper midrange emphasis due to the more detail. Cheaper speakers of the day, where muddy and very chesty sounding so this may have been a more desirable characteristic for me. It's been over 20 years so I can't remember what I thought back then.

(This may sound like a silly question).

What does it sound like if the tweeter (and/or midrange) speakers are completely disconnected, with only the woofer without any crossover?

The only possible reference I've heard, is playing a stereo through a stack guitar amplifier. IIRC, there were four speakers per cabinet which were likely 12" or 14" speakers manufactured by Celestion.

The highs are completely missing, and it has a very very muddy + "chesty" quality sound. Not much low end bass either. (This lack of low end is likely due to the fact that guitar amp spakers are designed to handle a lot of continuous punishment from a heavily distorted signal, and not for "fidelity" quality).

 

[JohnRice]

(This may sound like a silly question).

What does it sound like if the tweeter (and/or midrange) speakers are completely disconnected, with only the woofer without any crossover?

The only possible reference I've heard, is playing a stereo through a stack guitar amplifier. IIRC, there were four speakers per cabinet which were likely 12" or 14" speakers manufactured by Celestion.

The highs are completely missing, and it has a very very muddy + "chesty" quality sound. Not much low end bass either. (This lack of low end is likely due to the fact that guitar amp spakers are designed to handle a lot of continuous punishment from a heavily distorted signal, and not for "fidelity" quality).

It would tend to sound like it was in the next room.

 

[Mike Up]

(This may sound like a silly question).

What does it sound like if the tweeter (and/or midrange) speakers are completely disconnected, with only the woofer without any crossover?

The only possible reference I've heard, is playing a stereo through a stack guitar amplifier. IIRC, there were four speakers per cabinet which were likely 12" or 14" speakers manufactured by Celestion.

The highs are completely missing, and it has a very very muddy + "chesty" quality sound. Not much low end bass either. (This lack of low end is likely due to the fact that guitar amp spakers are designed to handle a lot of continuous punishment from a heavily distorted signal, and not for "fidelity" quality).

Back in the 80s it was very common to have inexpensive stereo system with tower speakers that had only one driver that was full range. Sound design brand comes to mind. About as cheap as they come. Look like a full size stereo setup with a chassis that mainly empty but for a very small power supply, amp, switching circuit, and tuner that took up maybe 1/16th of that chassis.

I believe this is the same one I had that made me appreciate better gear but was a nice Christmas gift from my parents.

Those full range speakers sounded really bad, no treble, muddy sound, no articulation, poor soundstage, and poor imaging. Most boomboxes with 2 way speakers sounded much better.

I would guess they would sound as bad when frequency was concerned. Soundstage and imaging would likely be better with a good speaker missing the tweeter.