Safety first

[Sansiiro]

Hello!

I have old XS-305RDS (https://www.hifiengine.com/manual_library/pioneer/sx-305rds.shtml) Pioneer Amp and new Heco Victa Prime 702 (https://www.heco-audio.de/en/downloads/victa-prime-702) speakers.
I use them mainly with chromecast audio. They work together great!

But safety first.
I have no reason to push the volume all the way up when listening to music,
but there are situations where I can not control the usage habits of other people,
and such a scenario CAN HAPPEN.

My question to the forum is: what is the main risk with such a scenario, where the volume is turned way up to
the maximum?

And would the risk of damaging my equipment be lesser if I had more powerful amp with more wattage?

I hope someone can answer me and thank You very much!

24195

[nonuffin]

The biggest risk to any system is not having enough power rather than having too much power. When an amplifier runs out of power, it is called "clipping" which means there is effectively direct current running through the speaker voice coils, which turns them into heater coils and they either burn out or distort the voice coil former and renders the drivers defective. The onset of distortion should not be ignored as that is a good sign the system is in distress.

To a degree you should ignore power ratings of amplifiers and speakers. It is far safer to run a 100 watt amplifier into 10 watt rated speakers, than run a 10 watt amp into 100 watt speakers, as the 10 watt amp is likely to clip.

However, this is not a rule set in stone as some amplifiers rated at less than 10 watts that can kick ass without running out of power :eyebrows:

[Pigmy Pony]

An underpowered amp would probably be worse for your speakers, as if overdriven, the signal will start clipping and I believe that is quite bad for the speakers' voice coils. Some better informed post should be along shortly, just as soon as they get out their lazy beds. :)

Perhaps some kind of 'bump stop' could be stuck on the volume control, that physically stops the knob at a certain point.

[Pigmy Pony]

The biggest risk to any system is not having enough power rather than having too much power. When an amplifier runs out of power, it is called "clipping" which means there is effectively direct current running through the speaker voice coils, which turns them into heater coils and they either burn out or distort the voice coil former and renders the drivers defective. The onset of distortion should not be ignored as that is a good sign the system is in distress.

To a degree you should ignore power ratings of amplifiers and speakers. It is far safer to run a 100 watt amplifier into 10 watt rated speakers, than run a 10 watt amp into 100 watt speakers, as the 10 watt amp is likely to clip.

However, this is not a rule set in stone as some amplifiers rated at less than 10 watts that can kick ass without running out of power :eyebrows:

There you go Veiko, a proper explanation! We've both learned something there.

[walpurgis]

Some NAD amplifiers offer 'soft clipping'. This provides a degree of protection.

[walpurgis]

Clipping: https://www.prosoundweb.com/topics/education/why_should_we_care_about_power_amplifier_clipping/

[Sansiiro]

Thank you Pigmy Pony!

[Sansiiro]

Thank you very much for an educated comment! I would like to ask, what kind of amp wattage would you consider ideal for these speakers?
I have currently 60+60 w amp (see the specs sheet), but the speakers have power handling 170 RMS / 300 Max.
I know that it doesn't just all depend on one figure, as you said yourself, but may be you can give me a little reference? I feel like 60 W is probably not ideal and I am keeping in mind this
problem of clipping.

[Macca]

The Pioneer you have should be fine. Looks like a fantastic vintage receiver.

There's no technical way to prevent someone whacking the volume all the way up and maybe blowing the speakers, that could happen regardless of the amplifier power. Try laying down the law with them before hand, threaten them with torture and death should they go within 5 feet of it. Or disconnect the speaker cables when you are not using it.

[walpurgis]

Your speakers have decent sensitivity, so I think clipping is unlikely. In fact, you would probably be OK with as little as 30 watts per channel, but realistically regard 50 watts as a workable minimum.

Other than that, as the power handling is generous, you could use just about any amp you like. The quoted impedance is 4 to 8 ohms, so it probably averages out at around 6 ohms which shouldn't bother modern amplifiers.

[Mike Reed]

Whereas the above suggestions and explanations are spot on, I'd say that the only way to ensure safety in any hifi kit situation is to ensure that which you say you can't ! Nobody but nobody (except one or two trusted bake-off friends) has touched my kit in over half a century, despite three children and I've not known any other serious audiophile differing from this. For total safety, I think this is the only guaranteed route.:)

[Pigmy Pony]

One sure way to get me to kick off would be to place something (anything) on top of the deck, speakers or any of the kit. Fortunately everyone here knows better. You need to set your stall out from day one, saves a lot of grief later.

[Sansiiro]

Big thanks to everyone. Your great comments are helping me a lot! It's very nice also to hear praise for the receiver - my dad gave it to me alongside with 2 35w Estonia speakers (https://audes.ee/static/estonia_35_as_021.jpg), which were manufactured 1987. Estonia is my home-land, and also a company which was founded in 1935, and it now is called Audes. Also a Piano Factory (http://www.estoniapiano.com/). Anyway, these speakers are kind of rarity and only recently one of them started crackling. My father told me never to sell them so I guess I will give them back to him now when I have new ones. I don't think it helped that the one that failed was closer to the sauna in my house. Back in day, his first speakers my father made himself, I cannot exactly tell you why. Nowadays we also have a company Estelon (http://estelon.com/) here, which makes high-end speakers and has gathered some respect.

I definately will tell the regular-suspects to respect the equipment. Also I have now realised that the old mp3-s don't sound quite as good as the music bought from Google Play Music, as I use chromecast audio as the player. I hear the CC shouldn't be the bottleneck - I also bought decent cables and I hear it is rocking 24-bit / 192kHz. But I certainly need to check the bitrate of these old mp3-s and probably rip most of the cd-s again - being younger I guess we have accepted all-kind-of crap for our listening-pleasure, and only now I am eager to notice the quality.

I have about 5000 songs in Google Play Library, but only about ten albums from Google Play itself, including Jeff Beck "Guitar Shop", Zappa "Freak Out!", Marillion "F e a r", also bunch of estonian music. Thanks again for your comments!

[Pigmy Pony]

"Freak Out" - that's one I haven't heard in a long time, first FZ album I ever heard. "Trouble Every Day" was my favourite track. If you like early Zappa, "Hot Rats" and "We're Only In It For The Money" are worth checking out.

[Sansiiro]

Yeah. Zoot Allures also comes to mind and Broadway the Hard way for comic relief (or was it blessed relief). Also sexual harassment at workplace, and everybody tends to like watermelon-track. I have about 40 albums of zappa, most of them copies, as my dad bought them way back. After copying of course I have ripped them to mp3. My good friend even has been to Zappanale two times, a festival in Germany. I have not had the opportunity to do it, but I'm planning on. And I think one might do a lot worse than Coldplay, believe me :)

[Macca]

. And I think one might do a lot worse than Coldplay, believe me :)

I wouldn't be so sure...

[Pigmy Pony]

Synesthesia sufferers commonly report seeing beige when subjected to Coldplay.

[Sansiiro]

Your speakers have decent sensitivity, so I think clipping is unlikely.

That is good to hear. At first your post got me wondering, because as I understand the regular speaker sensitivity varies from 85 - 105. So I could not see why you would call the sensitivity decent, since it is only 91db.
Later I read, that a high sensitivity might mean very light drivers, which due to that are easier to distort and defect. So possibly You meant by "decent" that sensitivity is NOT too high?

[alphaGT]

They make fuses, or breakers, designed to protect your speakers. I know I’ve seen them in the Parts-Express catalog. Although, it may require some math to decide what size you need to protect your speakers from your amp. If clipping, or just plain amperage, heat the voice coil enough it will trip the breaker, or blow the fuse instead. I had a pair of speakers once that had fuses, I eventually blew them, opened the speaker to discover they existed, and removed them from the circuit. I really didn’t hear any difference whether they were in or out. So adding them shouldn’t hurt your sound quality.

Russell