Underpowered amps vs overpowered amps

[Asit]

Hi dragonxwas,

You and me are not important here. The question is what is written for general consumption. Knowledge from the net can very often be wrong. I just took some pains in explaining the most plausible effects of clipping on the tweeter in as simple a language as possible. And I wanted to make it very clear that the very last point that you quoted again in your last post is very misleading, if not wrong, as far as I understand it. I have not really understood the point in your very last post, except your dissatisfaction.

I understand my previous long post may not be suitable for everybody, because everybody is not analytically-minded. In any case, there is nothing in that post that anybody having gone through just high school wouldn't understand (there is mention of Fourier decomposition there as just a name, but readers did not need to know about it, because I explained everything that readers needed to know). What is needed is actually the attitude and patience of going through a long post where reasonings unfold in a hierarchical manner. Are you trying to say one should write wrong things in a short and simple way because that's easier to understand? I am sure, you are not.

Lastly, as you say you didn't know the level here because you are new, and I accept that and welcome you with open arms (as I did in my previous post also), but is it right then on your part to assume something in the negative way (as you did in your last post: "most posters ...")? I just want everybody to be respectful of each other, and I have said it many times that this is the one major thing that keeps me away from Internet forums and makes me wonder if all this effort is worth anything at all.

You do not have to answer any of these questions. I know you are a knowledgable and enthusiastic new member of HFV, and can share your experience with others very happily so that our community becomes bigger and wealthier. I do not have the attitude that I know more than you do or vice versa, but I do reserve (as everybody else also does) the right to respectfully point out anything that, to my judgement, is not appropriate.

Do have a happy stay here.

Regards.

 

[haisaikat]

Asit da and others,
I was forwarded the following link by my friend mandark on this forum regarding the specs of Onkyo 608 receiver as available under the link Onkyo TX-SR608 - 7.2-Channel 3-D Ready Home Theater Receiver | Model Information | Onkyo USA Home Theater Products which is from the Onkyo USA website.

It is quoted over there that for 608 receiver

Dynamic Power
240 W (3 ohms, 1 ch)
210 W (4 ohms, 1 ch)
120 W (8 ohms, 1 ch

So it seems that even the 120 Watts at 8 ohms is for 1 channel at a time and not for all simulatneously. So even if the input power of onkyo is higher the specs suggest that not all of that is delivered sumltaneously in all channels at peak.

Unfortunately I am yet to find out some similar facts for Yamaha and Denon. I will look for some user manuals as another forum member suggested to me on another thread
http://www.hifivision.com/amplifier...de-side-feature-comparision-3.html#post229500 and see if something can be uncovered from them.

Another thing is that in the SKS traders where we demoed the Aviano 2 and 6, the 2 channel amplifer used for music was CA AZUR 650A (Input around 650 Watts while output per channel is 75 Watts at 8 ohms) and the 7.1 receiver we listened movies with was CA AZUR 650 R costing around 80k and but max input power is 1400 Watts while the specs boast one line produly as below

rated as True power output of 7 x 100 watts rms per channel, 8 ohms all channels driven

The link to the specs is below

Specifications / Azur 650R 7.1 AVR with HDMI 1.3c reception and processing / Azur / Products / Cambridge Audio

 

[haisaikat]

This is a repost of the same post that I had made in another thread...

This Sunday we (me, mandark, subhadeepgayen) finally made the purchase of Denon 1911 for 40K each from profx and speaker we had already ordered Aviano 6 (me and mandark),Avinao 2 (subhadeep), Aviano 5 and 1 (All 3 of us). The total speaker package of 5.0 came down to 69K for me and mandark (with Aviano 6 as fronts) and 50K for subhadeep (with Aviano 2 as fronts).

We took delivery of one set of 5.0 speaker set from SKS and took it to profx (they were co-operative in allowing us to pair and listen 3rd party speakers). Earlier we had listed to them using Yamaha RX-V667 in SKS and now we heard them using Denon 1911 in profx. The Denon sounded better but we must say that tuning plays an important role and we believe that Yamaha could have given a better output if tuned properly.

On the question of power matching I would say that Denon was able to drive the Avianos in 5.1 mode properly in some high bassy scenes at a volume level of -12dB. For 2 channel music the Denons did quite well and at profx they tested it with sound raised to -4dB when it sounded quite loud to us.

However I must say one thing which re-iterated what Asit da had expressed earlier. The 2 channel music sounded quite better when the same speakers were coupled in SKS with Cambridge Audio 650A which is a dedicated 2 channel amp. Also significat amount of bass and overall effect reproduction difference was noticable in 5.1 mode w.r.t Yamaha 667 in SKS when playing Dare Devil using Cambride Audio 650R amp which is a 7.1 receiver with 1400Watts power consumption. But both of them are very high blow to our pockets 650A ~ 60K and 650R ~ 80K. We could not test the same track with Denon since they were not available in profx, auditioned with Avatar BD.

All of us did agree to one fact though that tuning plays a major role in the setup and affects the final delivery of the show so we have to learn first how best to tune our amps to get the best out of them.

My thanks to all for so many important views and suggestions which helped us justify several things before buying which we did not know earlier.

My thanks to mandark (and his broher) and subhadeep for all the support on this sunday in loading and unloading all those heavy speaker boxes several times at different places.

I will post pics a little later once profx does the setup (amp yet to be delivered) and all is in place. Profx will be charging me ~ 800 for installation (cash on site) since I did not take the whole package from them and I was not willing to set up all by myself.

Also the chord cables for fronts are yet to be delivered.

 

[no1lives4ever]

All of us did agree to one fact though that tuning plays a major role in the setup and affects the final delivery of the show so we have to learn first how best to tune our amps to get the best out of them.

Unless you have a specially treated HT room, definitely set the system up using Audyssey auto setup. The speaker level and distance setup done by the Audyssey is quite accurate. This is one area where the auto setup seems to work very nicely.

The Audyssey EQ curves are designed for movie playback and you may not like it for music. So, if you do not like the Audyssey EQ curves, then you can use the manual EQ and start by copying the Audyssey EQ curves. On my 1910, I can flip between the three Audyssey curves, no eq and manual EQ. So you can easily store one set for music and one for movies.

Do note that the Audyssey setup sets up your AVR to play at reference volume when the volume is set to 0. So do your demos at that volume.

In my experience, Audyssey does a very good job with initial setup and tuning and mostly you do not need to change anything after that. The real beauty of the Audyssey Multi EQ comes out when you listen to surround mixes. With most surround mixes, my speakers just disappear. I could never replicate the same level of speaker matching using the manual EQ.

You should also read through batpig's denon guide here: BATPIG'S DENON-TO-ENGLISH DICTIONARY This helped me a lot when I was setting up my 1910.

-- no1lives4ever

 

[Asit]

Saikat, Subhodeep and Mandark,

Heartfelt congratulations to you for your purchases. I wish you all and your families happy listening and watching. Your report reminds me of the day when after months of looking around my wife and I brought home our Canton speakers in Germany. We were really immersed in joy that day, although we did not yet buy anything else at that time to listen to any music.

As I can see, you guys worked pretty hard on the selection, and I truly hope all that work pays off in terms joy of owning your system from now on. Best thing you did was to carry your speakers around for a direct audition with the avr in question. Boy, quite a lot of activity.

I am sorry I was not much help in anything. Firstly, my schedule mostly keeps me away from being a regular visitor to the forum. and then I do not have any direct experience with AVRs.

Just one small word of caution. Use your system carefully. Always turn on your source (DVDP/CDP etc) first. Wait for about 5-10 seconds. Then turn on your amp/avr. Follow the reverse sequence while switching off. That is, first stop whatever is playing from source. Then power off the amp/avr, at last power off DVDP/CDP. Also, before both occasions of powering on and off, first reduce the volume knob of amp/avr to minimum. Lastly, let the amp/avr warm up for at least a few minutes, before you start playing stuff.

Regards.

 

[haisaikat]

Thanks for the link... I will surely go through it.

 

[sunild]

Dear Asit ,

I need some clarification about the speakers and power amplifier ,i am getting Onkyo NR-609 ,which has got power outputs ,100 Watts per Channel at 8 Ohms, 20 Hz?20 kHz, 0.08%, 2 Channels Driven, FTC; 125 Watts per Channel at 6 Ohms, 1 kHz, 0.1%, 2 Channels Driven, FTC.

and i have old SONY MHC-RV900 5.0 speaker which i am going to use it with onkyo NR-609 ,specs of the speakers as follows.
The following measured at ac 120,127.220,240 Volts 50/60 HZ

Continues RMS Power output (reference)

Front Speakers 100 + 100 Wats (6 Oms at 1 kHz,10% THD)
Center Spaker 40 Watts ( 8 ohms at 1 kHz 10 % THD)
Rear Speakers 40 +40 Watts (6 Ohms at 1 kHz 10 % TSD).

As i am not familiar with power ratings ,i need inputs from you ,what precaution i have to take while using this combination of AVR and Speakers.

Thanks
Sunil

 

[goyal.sanchit]

I have bought the denon avr 1311 and planning to buy jbl cinema 300 along with it.

Before purchasing the avr many members told that matching avr and speaker is not an issue and the same was told by every dealer I asked. But this thread I believe talks about totally the opposite thing.


Without getting too technical how important is it and what should I do now?

 

[banumolu]

The underpowered amps are definitely more dangerous to speakers. I know this from practical experience - a friend destroyed one of his speaker drivers by using an underpowered amp. An overpowered amp will control the speakers properly by providing the right amount of current required, so the sound quality will be better as well.

 

[omishra]

The underpowered amps are definitely more dangerous to speakers. I know this from practical experience - a friend destroyed one of his speaker drivers by using an underpowered amp.

This is possible only if amp does not have protection. If amp has protection (for speaker and self) against clipping and subsonic waves then it could have been avoided. I always taken care to add detection against DC, under 3Hz wave as well as clipping in output and disconnecting speakers for that moment using relay based protection.

 

[sanver1971]

which amp is best for vintage pioneer cs 905 speakers

 

[trittya]

An amplifier must be 1.5X times the power handling capability of speaker it is driving. The music signal has very high average to peak ratio with respect to its program content.

Underpower amplifiers clip easily and which can burn the voice coils easily especially tweeters.


Hope this Helps.

Hmmmmm . . . .
Now I know what happened to the tweeters in those 2.5 way floorstanders of mine . . . .

 

[heliumflight]

double post

 

[heliumflight]

An amplifier must be 1.5X times the power handling capability of speaker it is driving. The music signal has very high average to peak ratio with respect to its program content.

Underpower amplifiers clip easily and which can burn the voice coils easily especially tweeters.


Hope this Helps.

Sir,

Can you advise me if I'm safe in regards to power requirements (clipping)? At one point I had connected my Luxman poweramp directly to the computer and felt it was getting strained. Then, I placed a Pre-Sansui in the chain and I feel that the poweramp does not get that hot as it used to get before. I raise the preamp knob to 1 o'clock position and the sound is warm and smooth. Also like to share the Luxman amp has 3 taps for 8/6/4 ohms, so am I safe at high volumes to get room filling sound in room size 150 sqft?

Thank you for your time

--
helium= HTPC Asus Xonar STX + Sansui Au-317 + Luxman M-06a (Class A 55W)+ SMG Magneplanar/ Polk Audio LSi9 /Vintage B&W DM4

 

[kanwar]

Sir,

Can you advise me if I'm safe in regards to power requirements (clipping)? At one point I had connected my Luxman poweramp directly to the computer and felt it was getting strained. Then, I placed a Pre-Sansui in the chain and I feel that the poweramp does not get that hot as it used to get before. I raise the preamp knob to 1 o'clock position and the sound is warm and smooth. Also like to share the Luxman amp has 3 taps for 8/6/4 ohms, so am I safe at high volumes to get room filling sound in room size 150 sqft?

Thank you for your time

--
helium= HTPC Asus Xonar STX + Sansui Au-317 + Luxman M-06a (Class A 55W)+ SMG Magneplanar/ Polk Audio LSi9 /Vintage B&W DM4

Heliumflight,

Are you saying that you are using Integrated Sansui amp as preamp for the LUXMAN amplifier ?

If yes, then its very surprising for me because of many reasons.

Class-A becomes HOT when running with no signal or very low signal.

Am i missing something???:sad:

 

[kanwar]

Sir,

Also like to share the Luxman amp has 3 taps for 8/6/4 ohms, so am I safe at high volumes to get room filling sound in room size 150 sqft?


helium= HTPC Asus Xonar STX + Sansui Au-317 + Luxman M-06a (Class A 55W)+ SMG Magneplanar/ Polk Audio LSi9 /Vintage B&W DM4

Kindly , tell me where are the 3 Taps?

I can only see One pair for each channel. Your model is different ?

 

[AVM]

I have been listening to my Tannoy MG 15 switching between 2 ampflifiers with power rating at opposites of extreme. One is EL84 rated at 10watt push pull and the other is a SS power amp rated at 180 watt with a pre tube. Though the pre power seems to give me a sense of control, its the little 10 watt fella that sounds very musical to me. The speakers just sing beautifully. Infact I have also been blessed with an opportunity to even try them with a more powerful EL34 mono blocks (about 35 watts), but its the EL84 without being pushed over 1 O clock that wins.
Given the discussion on power ratings I am not sure if I should be driving them with minuscle power.

Also, the EL34 has fresh out of the box tubes whereas the EL84 has been around for a quite a long time, so not sure if this could be the reason.

Appreciate the advise.

 

[asliarun]

I have been listening to my Tannoy MG 15 switching between 2 ampflifiers with power rating at opposites of extreme. One is EL84 rated at 10watt push pull and the other is a SS power amp rated at 180 watt with a pre tube. Though the pre power seems to give me a sense of control, its the little 10 watt fella that sounds very musical to me. The speakers just sing beautifully. Infact I have also been blessed with an opportunity to even try them with a more powerful EL34 mono blocks (about 35 watts), but its the EL84 without being pushed over 1 O clock that wins.
Given the discussion on power ratings I am not sure if I should be driving them with minuscle power.

Also, the EL34 has fresh out of the box tubes whereas the EL84 has been around for a quite a long time, so not sure if this could be the reason.

Appreciate the advise.

This seems to be a common pattern. One of the reasons I replaced my monitors (besides other personal reasons) was that it just didn't pair well with my solid state amp (125W - 8ohms, 200W - 4ohms). However, lots of people love the same speakers with much lower wattage tube amps.

I know people say "a watt is a watt", I do feel that for music, tube amps seem to be a lot beefier than their wattage implies. Or at least better suited (musical as many call it).

But conversely, my new speakers pair extremely well with my SS power amp, and they're significantly easier to drive than my old ones.

 

[heliumflight]

Kindly , tell me where are the 3 Taps?

I can only see One pair for each channel. Your model is different ?

It's in front of the panel

 

[heliumflight]

Heliumflight,

Are you saying that you are using Integrated Sansui amp as preamp for the LUXMAN amplifier ?

If yes, then its very surprising for me because of many reasons.

Class-A becomes HOT when running with no signal or very low signal.

Am i missing something???:sad:

Yes, I use Sansui Au-317 as a Preamp and take it all the way to 1 oclock position. Now I find that the Luxman is less hot. Also to let you know the Luxman has attenuatar control which I keep at 50% open.