Auditioned Marantaz PM8003+Quad11L2

[venkatcr]

Of course as long as we don't notice something really bad, maybe it's cool.

- Actually it is quite simple.

Let us take an skewed example. let us say you have an amp that has a maximum capacity of 50 watts per channel. And, let us say, you are driving speakers that can be driven upto 100 watts.

As you go on increasing the volume, the amplifier will reach its limits before the speaker does. As you continue to increase the volume, the amplifier will simply cut off or 'clip' the sound signal. What usually happens is the that low frequencies first and then the high frequencies start getting chopped off from the sound signal. What started as a sine wave will become a distorted square wave.

Unfortunately humans have a great capacity to listen to clipped signals without realising what they are hearing. In hard rock, for example, guitar amplifiers are usually clipped far beyond their capacity as that distorted sound is what the artists are looking for.

Cheers

 

[prash2k01]

- Actually it is quite simple.

Let us take an skewed example. let us say you have an amp that has a maximum capacity of 50 watts per channel. And, let us say, you are driving speakers that can be driven upto 100 watts.

As you go on increasing the volume, the amplifier will reach its limits before the speaker does. As you continue to increase the volume, the amplifier will simply cut off or 'clip' the sound signal. What usually happens is the that low frequencies first and then the high frequencies start getting chopped off from the sound signal. What started as a sine wave will become a distorted square wave.

Unfortunately humans have a great capacity to listen to clipped signals without realising what they are hearing. In hard rock, for example, guitar amplifiers are usually clipped far beyond their capacity as that distorted sound is what the artists are looking for.

Cheers

does it mean that difference between quad at 86db and PM8003 at 70W is the reason of clipping? but I have already stated in my earlier post I saw clipping at 9-10 o clock of the volume knob. ................so does it mean that much before to max 70W it start's clipping? ....means that exactly i can get 63w/channel (70*9/100=63w if 9 o clock volume knob is max)

 

[COOLDUDE7808]

i will try not to get too technical here --

Generally your amp power should be at least 1.5 to 2 times your speaker's continuous output (Or atleast equal) . this will ensure that the amp is able to provide sufficient power to drive your speakers ........ (read specs and match RMS and Impedance of both amp and speakers)

If amp power is less ....then the speakers try to draw more power from the amp ....then the amp is capable of generating .....this will result in the amp sending out a distorted signal to the speaker ........this leads to clipping .......in the worst case scenario .........both amp and speakers may get damaged .....

In case of speakers its mostly the tweeter which goes off .....so you will notice a drastic change in the sound quality ......(Brightness or treble will get reduced , detailing will be less , bass becomes fuzzy)

amps generally have a protective circuit and hence they get saved ....



One more thing is Senstivity --- if speaker sensitivity is more , it will be more loud at a lesser volume .....so you may not turn up the volume button beyond a certain point .........this means less demand on the amp to drive your speakers ....and hence less probability of clipping .........In other words clipping mostly occurs when the system is played at high volumes .........(if amp power is less than speakers)


Now Marantz PM7001 is 70W at 8 ohms and Quad 11L2 is 85W @ 6 ohms ...Sensitivity of Quad at 86db is also low .......

Refer to the link below for detailed explanation

Why Do Tweeters Blow When Amplifiers Distort?

 

[COOLDUDE7808]

so does it mean that much before to max 70W it start's clipping? ....means that exactly i can get 63w/channel (70*9/100=63w if 9 o clock volume knob is max)

how do you do this calculation ? ...any link in the net that you can provide me with to understand this better

 

[prash2k01]

i will try not to get too technical here --

even I dont understand much technical details.............I love listening music.........with good details and at listening level(not loud).

even i did not understand why ppl wants loud, loud and loud.......while their ears has some limits.

 

[panditji]

Please wait for the speakers to burn in properly...I too was disappointed when I heard the speakers right out of the box...But after 100-150 hours the sound just changed....You will not find any listening fatigue after 150 hours and if you do then you need to make changes in the setup/room acoustics...
I would advise you to wait for 150 hours of burn in and then evaluate....

 

[prash2k01]

Please wait for the speakers to burn in properly...I too was disappointed when I heard the speakers right out of the box...But after 100-150 hours the sound just changed....You will not find any listening fatigue after 150 hours and if you do then you need to make changes in the setup/room acoustics...
I would advise you to wait for 150 hours of burn in and then evaluate....

sure pandtji...........I will wait............
even i have not only finalized but also brought the combo at home two weeks back.

sorry for 1 more stupid question..........since or as stated that clipping is because of difference between sensitivity of amp and spkrs ...........so how after burn in ...........this difference will be removed............ I know this is very silly question.

 

[venkatcr]

Prakash, you are confusing too many issues here - clipping, ear fatigue, burn in, and amplifier speaker matching.

At the outset, please remember that irrespective of how much you burn-in speakers, it's specs will remain the same. And if there is a mismatch with the amp, that will also remain.

None of this has anything to do with what you experienced. What you experience was ear fatigue. This means that the amp was able to drive the speakers quite well and at a high amplitude.

Why does one get ear fatigue? It's caused by a combination of TTS (Temporary Threshold Shift) and general fatigue. The condition we call ear fatigue usually occurs after many hours of listening audio at high SPL's. It causes us hear the sound differently. At times there could also be slight pain in the ear.

Since Quad is a good speaker, I can only conjecture that, unknowingly, you have been listening at high volumes. As long as you are not treating yourself to high frequencies (screeching noises), reduce the volume to a level where it is comfortable for your ears.

Cheers

 

[srramanujam]

Excessive use of ....... (or) ------ in the music can also cause a lot of ear fatigue.

In online forum, some see it as indifference to other members, some see it as a natural way of expression.

In music though, it can cause a lot of problems. Repeated use of ....... causes the speakers to demand more current and the amp cannot match upto it. At this point you have clipping. Excessive use of ------ increases SPL and causes ear fatigue.


This phenomenon is more pronounced when listening to british sounding gear - Quad for example.

 

[prash2k01]

Hello venkatcr sir,

you are confusing too many issues here - clipping, ear fatigue, burn in, and amplifier speaker matching.

ya i think so many issues has been mixed here.........let me clarify them one by one.

At the outset, please remember that irrespective of how much your burn-in speakers, it's specs will remain the same. And if there is a mismatch with the amp, that will also remain.

at least the above point I understand very well.

None of this has anything to do with what you experienced. What you experience was ear fatigue. This means that the amp was able to drive the speakers quite well and at a high amplitude.

Why does one get ear fatigue? It's caused by a combination of TTS (Temporary Threshold Shift) and general fatigue. The condition we call ear fatigue usually occurs after many hours of listening audio at high SPL's. It causes us hear the sound differently. At times there could also be slight pain in the ear.

the realized the ear fatigue at the time of audition.......at volume knob at 9 o clock ......just to check ....how far or how loud it can go............and it was only for few seconds.............not for long hours...............and I did not get any pain in my ears.
I usualy hear at 4-5 o clock of the volume knob at my home.

when I asked for the possible reason for the fatigue I found the followng reasons:
1. CDP..........it was CA CD340 at the time of audition.
2. synergy or difference between specification of amp and spkrs.
3. burn in.

so i didnt mixed them up........it automaticlly mixed while finding the reason..................

 

[venkatcr]

From what I have been able to understand, it looks as if you drove the speakers and amp very hard for a short time. Nothing is at fault here, excepting that your ears complained of the loud noise.

Keep the volume at a comfortable level, high enough that all the lyrics are audible, and all the instruments are clearly discernible. If you do not have a SPL meter, one way to judge is to look at other people. Children, in particular, will close their ears with out any inhibition.

If you are able to get your hands on a SPL meter, keep the volume at less that 75dB at your listening position.

Cheers