Help me stop the screeching buzz

[manwell]

I have a very basic (aka: affordable) a/v setup; Panny RX-V650 powering a 5.1 all Infinty Primus system. The problem I'm having is with the ps-12 sub. Everytime I fire up the system I get this terrible screech/buzz, about a second long, out of the sub! It will, on occasion, do this even when the system is powered down and just watching the TV. I leave the power switch on the back of the sub on, which will send the sub into standby after idle. This didn't happen when this system was first put together late 2006. Thanx for u're help.

 

[markw]

Sounds like the sub has major issues. Either replace it or find a tech who knows how to repair them, whichever is more cost-effective.

 

[TLS Guy]

I have a very basic (aka: affordable) a/v setup; Panny RX-V650 powering a 5.1 all Infinty Primus system. The problem I'm having is with the ps-12 sub. Everytime I fire up the system I get this terrible screech/buzz, about a second long, out of the sub! It will, on occasion, do this even when the system is powered down and just watching the TV. I leave the power switch on the back of the sub on, which will send the sub into standby after idle. This didn't happen when this system was first put together late 2006. Thanx for u're help.

Subs seem very prone to power supply failure, and yours is joining the crowd. The unit needs service. Until then unplug it every night and when you leave home. This is important advice for your safety and that of your home.

 

[manwell]

Thanks both markw and TLS Guy. Interesting TLS Guy 'bout the threat to my safety. I do take this seriously and would you please explain in more detail what the danger could be. Looks as though I'm in the new sub market. Any sugestions for an affordable sub to match up well will my system?

 

[TLS Guy]

Thanks both markw and TLS Guy. Interesting TLS Guy 'bout the threat to my safety. I do take this seriously and would you please explain in more detail what the danger could be. Looks as though I'm in the new sub market. Any sugestions for an affordable sub to match up well will my system?

All electronics that is malfunctioning and not taken out of service is a potential hazard. However in your case it sounds very likely that you have power supply capacitors discharging though the dielectric between the plates. Whist this seldom does significant damage to houses, in terns of fire, it can. More often when kept in service it results in a dramatic smoke up. We have had pictures posted here before, of subs doing this.

I'm not the one to ask for commercial subs, I just know when I hear most, I don't like them and so roll my own. Any that have not severely offended me have been quite pricey. In my main system I don't use them at all.

 

[manwell]

Thanks, TLS Guy, for taking the time with a neophyte. Interesting 'bout "smoke out". I certaintly don't need to alarm the wife! I unpluged the sub 'bout ten minutes ago. I find no need for the sub when listening to music but do like to have the sub handle the LFE in the 5.1 soundtracks.

 

[sparky77]

I've had the same problem several times, and every time it was the result of either a bad cable, or coroded connections. Try cleaning the connections with a fine emery cloth, if that doesn't work, try a different sub cable.

 

[manwell]

I've had the same problem several times, and every time it was the result of either a bad cable, or coroded connections. Try cleaning the connections with a fine emery cloth, if that doesn't work, try a different sub cable.

I suspected that I may have had a cable problem, at least that is what I'm hoping it only is. I changed out my Blue Jean to an Impact and it has made a difference in only that the screeching is not as loud as it was, much more subdued. I'll now try the emery cloth and let you know if this helps. The sub is only 3 years old and used only occasionally. Thanks

 

[sparky77]

Sounds like an intermittent ground loop issue. If you live in an old house, try replacing recepticals. For some reason some amps will build up a static charge til builds to a level where it starts buzzing, then hits the level where it can jump the coroded connections and balance out the ground current, and clear out the ground loop.

 

[DJ in TX]

I'm not the one to ask for commercial subs, I just know when I hear most, I don't like them and so roll my own. Any that have not severely offended me have been quite pricey. In my main system I don't use them at all.

So do you mean that you don't use commercial subs in your main setup, or you don't use subs at all?

This is interesting to me because I currently have only 2 bookshelves in my system (no other speakers). While I don't plan to add any other pieces to the mix for at least a year, I think that eventually I will want more bass and therefore may add a sub. So if you don't use subs, then what do you do to hit the lows?

 

[TLS Guy]

So do you mean that you don't use commercial subs in your main setup, or you don't use subs at all?

This is interesting to me because I currently have only 2 bookshelves in my system (no other speakers). While I don't plan to add any other pieces to the mix for at least a year, I think that eventually I will want more bass and therefore may add a sub. So if you don't use subs, then what do you do to hit the lows?

I don't use subs at all in my main system. I use these: -

And these: -

They are aperiodically damped transmission lines, hence my "handle". These lines go right to the low 20 twenties with 12 db rather than 24 db roll off. In their location the 3db point is 20 Hz. Qtc is 0.5 so the speakers are critically damped and free of boom and hangover.

If you click on my signature you can browse the rest of the album.

For my smaller system I use these isobarik coupled cavity second order subs, to augment the last octave of the Qb4 reflex main speakers. Again Qtc of the subs is 0.5, so they are also critically damped.

 

[manwell]

Sounds like an intermittent ground loop issue. If you live in an old house, try replacing recepticals. For some reason some amps will build up a static charge til builds to a level where it starts buzzing, then hits the level where it can jump the coroded connections and balance out the ground current, and clear out the ground loop.

Thank you sparky77 for taking the time. I feel or maybe sense the I have an electrical issue. Where it is coming from I just don't know!? I've changed my surge protector to start and then bought a different sub cable. I've ruled out the receiver. The thing is, after the initial screechbuzz is done it seems that the sub works fine?? But it does on occasion make this annoying noise during use. I've pretty much resigned to the fact that my sub is dying and may, as TLS Guy has warned, blow up! I've done a bit of reading here in these forums and else ware and discovering so much about subs that I don't know where to start. I'm certainly going to take my time and research

 

[manwell]

Where. What. You lost me at "a periodically damped"! This is not a place for me to start...but maybe? End up! WOOD it be a fair guess to to say they look home made? Custom made? See only more questions. My head is going to blow up before my sub! Does being an audiophile mean chasing an elusive sound of perfection? AHHHH

 

[TLS Guy]

Where. What. You lost me at "a periodically damped"! This is not a place for me to start...but maybe? End up! WOOD it be a fair guess to to say they look home made? Custom made? See only more questions. My head is going to blow up before my sub! Does being an audiophile mean chasing an elusive sound of perfection? AHHHH

Yes, the speakers are not commercial. I built the speakers in my friends cabinet shop with his foreman Bob. The speakers are too big to construct with just one builder, it takes two because of the size of the boards and huge weight of the units. I built the little subs in my own shop back in the late eighties.

I have not idea what it means to be an audiophile, on the whole they seem to be obsessed chasing the next loony tweak. I like physics and experience to guide me. Speakers are the sum of compromise and a blend of art and science.

As to your sub. I disagree with Sparky, a bad connection will not consistently malfunction at switch on, but a bad cap will. Your sub needs the power supply of the amp looked at. If you like it, I suspect it will be cheaper than getting a new one. Your other option is to modify to take another plate amp.

 

[DJ in TX]

I don't use subs at all in my main system. I use these: -

And these: -

They are aperiodically damped transmission lines, hence my "handle". These lines go right to the low 20 twenties with 12 db rather than 24 db roll off. In their location the 3db point is 20 Hz. Qtc is 0.5 so the speakers are critically damped and free of boom and hangover.

If you click on my signature you can browse the rest of the album.

For my smaller system I use these isobarik coupled cavity second order subs, to augment the last octave of the Qb4 reflex main speakers. Again Qtc of the subs is 0.5, so they are also critically damped.

Wow! All I can say is, your Title of Audioholic Ninja is well deserved. You're posts make me feel like a moron, which by comparison is true