Sennheiser HD558 impressions / review - Page 5

Quote:

Originally Posted by derbigpr 

You should be able to audition a DAC without buying it, would give you an idea of how good HD558's can sound.

Not many (if any) shops in England that let you do that.

Quote:

Originally Posted by RayleighSilvers 

What formula are you using? P=V*Z? Why do you divide the power by the total Impedance?

Here is how I calculate the voltage on the load (headphone):

  Vload = Vout * |Zload| / |Zout + Zload|

That is because the same current is flowing through the output impedance and the load (as these are serially connected), and the total impedance is the sum of the two impedances:

  I = V / Z = Vout / |Zout + Zload|

  Vload = I * |Zload| = see formula above

Power is calculated by dividing the squared voltage by the impedance.

Finally, the dB difference between the two calculated voltages (for 90 Hz and 2 kHz in the example) is the base 10 logarithm of the ratio of the voltages multiplied by 20.

Quote:

Originally Posted by stv014 

Here is how I calculate the voltage on the load (headphone):

  Vload = Vout * |Zload| / |Zout + Zload|

That is because the same current is flowing through the output impedance and the load (as these are serially connected), and the total impedance is the sum of the two impedances:

  I = V / Z = Vout / |Zout + Zload|

  Vload = I * |Zload| = see formula above

Power is calculated by dividing the squared voltage by the impedance.

Finally, the dB difference between the two calculated voltages (for 90 Hz and 2 kHz in the example) is the base 10 logarithm of the ratio of the voltages multiplied by 20.

 

Had to read your post so many times to get my head round it. I'm doing an electrician's course as well, it's shocking 

I've come across the 3 power formula's but the Vload= Vout*(ratio of Zload to total Z) I haven't come across. I definitely haven't come across the last formula you mentioned. Guess that's that's more to do with sound science than electrics.

EDIT* Silly me. Your talking about Volt drop aren't you? In a circuit the total voltage is spread out to push current along the different resistances.

I.e a 240V circuit that has a current of 24 amps and has 2 resistors in series (one at 7ohms, other at 3ohms for e.g.), volt drop across first resistor will be I*Z1 =  24*7 = 168v and second one will be 24*3 = 72Volts. 

So in the headphone example you gave Vout would be the total voltage, and at 2kHz (60 ohms at headphone), the circuit current would be   V/Ztotal = 1v/(100 + 60) = 0.00625 Amps. The volt drop across the line out (i.e the voltage used to push current across that resistor) would be 0.00625*100 = 0.625v and the voltage left over for the headphones to use would be 0.275v. 

Sorry for the lecture. I wasn't insulting your intelligence, you obviously know your stuff , I just had to type all that out to make sure I had everything right (My brain is slow).

So now the question of amps. I thought voltage doesn't change but looking at the formulas I'm guessing an amp actually increases the voltage rather than the current (since Impedance is a constant at a set frequency)? 

What amp do you guys use/recommend to get over the 558's impedance spike? I tried the fiio e6 and it didn't really do anything apart from increasing the volume. My sansa clip goes more than loud enough for my tastes

Quote:

Originally Posted by derbigpr 

I used mine with Fiio E9, Pro-ject Headbox SEII and Little Dot Mk5.  I liked them in this order, E9 being the worst, Mk5 being the best by far.  But E9 is more than adequate, however, even with proper amp, you can't expect 558's to become bass monsters, you'll just get more punch and more control from that 80-250 hz range.

What is the sound difference between those amps? I think I'm still trying to understand what bass is. I understand there is a difference between bass quality, impact, and quantity. When you say bass monsters what exactly do you mean? I'm just trying to get more impact out of my sound (i.e to feel the bass, the drums being hit, the guitars being strung, Flutes piercing the soul etc...)
 

Quote:

Originally Posted by derbigpr 

The differences between E9 and Headbox are mainly in sound signature, not so much in overall "sound quality". What I mean by that, Headbox doesn't sound like a much better amp, just sounds a bit different.  IMHO,  E9 is slightly warmish, but not very controlled. I found the bass to be slightly boomy with it.  Headbox SEII is fairly neutral with good bass weight and very smooth highs, but somewhat lacks energy.  Now MK5 is clearly in a different league.  Its very accurate, neutral with a hint of brightness, perfect for dark headphones. It has a bigger sound stage compared to other two. Everything sounds very separated and very clear with it, details are more apparent, and obviously, its got much more power than other two, so you don't have to crank it up very high. Its also perfectly quiet without absolutely any hiss whatsoever, even at full volume.  That is after a grounding cable isolation mod though.

 

Now, by bass monsters I mean quantity, punch.  HD558 have a pretty detailed bass, sometimes a bit out of control and loose, especially after a foam removal mod.  Bass has some punch, but it doesn't go very low, and it will never rumble or give you that subwoofer-like deep bass. It works well for drums, not so well for bass, bass guitar or synth bass. Also, the construction of HD558's is not quite as stiff as I'd like, it has some resonance while playing those very low bass notes, so it makes the entire sound seem loose in bass heavy songs.  Thats my biggest complaint about HD558's, they don't sound tight enough.  It might not be evident in most music, and especially if they are your only headphones, but compared to something like HD650, they tend to feel like the driver is held in place by spider webs when playing low-bass heavy music.

Hmm, I'm not getting that loose bass that you mention. Although I am a noob audiophile and my only sources are an onboard soundcard and a sansa clip. If you link the parts to the songs/music you mean (with the loose bass) it would be helpful, plus I can learn a bit about how to describe sounds. Thank you for your time btw 

Quote:

Originally Posted by derbigpr 

No problem, I started this thread, now I gotta be active it in.  

 

As for loose bass,  thats in any song where there are long deep bass notes...any music with for example bass guitar in it played on louder volumes.

 

This comes to mind:   http://www.youtube.com/watch?v=vYSiNyohNG8&hd=1

This sounds very very loose on HD558, and very tight, deep, subwoofer-like on HD650.

On the box of the 558's it says "outstanding Bass and Vocal projection". I'm kind of annoyed now. I'm surprised that the 650 is subwoofer like. Isn't it supposed to be reference level? I thought all reference levels were generally cold/bright, although this is completely from assumption. By subwoofer you mean bone shaking right? 

Quote:

Originally Posted by RayleighSilvers 

On the box of the 558's it says "outstanding Bass and Vocal projection". I'm kind of annoyed now. I'm surprised that the 650 is subwoofer like. Isn't it supposed to be reference level? I thought all reference levels were generally cold/bright, although this is completely from assumption. By subwoofer you mean bone shaking right? 

 

I have both 558's and 650's.  The 650's are far from cold and bright. They sound amazing to me. I love their thick warm sound.   The 558's maybe are a little faster and have better high's but the 650 easily out performs low down through the mids.  Clearer, cleaner and smooth. More detail.  They kindof made my 558's redundant to me.     I have been running my 558's with CmoyBB's and C421 with bass boost on. Really helps flesh them out and get a bit more out of the bottom end.  That was the only way I would listen to them.

 

Quote:

Originally Posted by syphen606 

I have both 558's and 650's.  The 650's are far from cold and bright. They sound amazing to me. I love their thick warm sound.   The 558's maybe are a little faster and have better high's but the 650 easily out performs low down through the mids.  Clearer, cleaner and smooth. More detail.  They kindof made my 558's redundant to me.     I have been running my 558's with CmoyBB's and C421 with bass boost on. Really helps flesh them out and get a bit more out of the bottom end.  That was the only way I would listen to them.

 

 

The 650's sound like a great piece of kit. Do they have much impact? Have you tried them with movies/Games?

Quote:

Originally Posted by RayleighSilvers 

The 650's sound like a great piece of kit. Do they have much impact? Have you tried them with movies/Games?

I wouldn't use impact to define them.. rather super smooth and detailed. I don't need impact or super punchy bass with this sound because its all there anyways. There is a million words written about the HD650's.  I liked my 558's but felt they are lacking a bit lower down, the HD650's give me the sound I want. I think my ATH-M50's still provide more bass but not as clear or smooth. More impact but its not anywhere near as nice. I think that comes with the closed vs open can discussion.  The 650's don't seem to shine until you use a decent amp from what I gather.  Mine seem to run fantastic off my C421. 

Great review.

I have similar feeling about HD558.

Does 558 become better with bur-in or just is me get used to it? I don't really mind.