Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › NuForce Icon HDP question . .
New Posts  All Forums:Forum Nav:

NuForce Icon HDP question . .

post #1 of 9
Thread Starter 

Just ordered the NuForce Icon HDP to pair up with my Ultrasone Pro900.  I'm also planning on ordering a set of desktop speakers - probably the M-Audio BX5-a or AV40's (haven't decided yet).

 

Question:  Can I power either of the M-Audio speakers directly from the Icon HDP (RCA>Speakers)?  . .  Or will I need to connect the HDP to another amp (maybe the NuForce amp) to power the speakers?

 

Thanks

post #2 of 9

It seems that both of those speakers are active speakers, which means that they have their own amplifiers inside the speaker enclosure. So you will not need an amp besides the HDP, which will act as a pre-amp for the speakers to make volume adjusting easier.

post #3 of 9
Thread Starter 
Quote:
Originally Posted by ESCS View Post

It seems that both of those speakers are active speakers, which means that they have their own amplifiers inside the speaker enclosure. So you will not need an amp besides the HDP, which will act as a pre-amp for the speakers to make volume adjusting easier.


Thanks for your quick response and explanation !!  The wife will be happy that I won't buy another piece of equipment biggrin.gif

post #4 of 9

Just to add, gain-match the active speakers to the HDP preamp, that way you can structure the gain to use the HDP as your master volume control, instead of reaching over to the speakers to manipulate the gain settings.

post #5 of 9
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post

Just to add, gain-match the active speakers to the HDP preamp, that way you can structure the gain to use the HDP as your master volume control, instead of reaching over to the speakers to manipulate the gain settings.



I'm still new to this stuff . . .  how do I do this?  Do you mean that I should get certain speakers that work well with the dac/amp?  If so, which desktop speakers would you recommend that would match well with the NuForce Icon HDP?

post #6 of 9
Quote:
Originally Posted by curtisinoc View Post

I'm still new to this stuff . . .  how do I do this?  Do you mean that I should get certain speakers that work well with the dac/amp?  If so, which desktop speakers would you recommend that would match well with the NuForce Icon HDP?


 

Well ideally you should get speakers that match the upstream components, but what I was talking about was for convenience and will apply to nearly any powered speaker or poweramp (with variable gain) and passive speaker. Think of it all this way: a passive speaker will have a gain knob, while most headphone amps have a gain switch. They're not exactly the same throughout but just to illustrate what they're for, the switch on amp lets you use normal gain on an efficient, low-impedance Grado SR325 and switch to high-gain for an efficient, but 300ohm Sennheiser or 64ohm, low-efficiency AKG. The variable gain however lets your speakers work with a wider range of possible sources - it could be an iPod through the earphone out, or the fixed 1-volt line out; or a CD Player with a fixed 2v line out; or a preamp output from a CD Player with an integrated variable output (like a Marantz), an integrated (head)amp (like a Musical Fidelity X-Can V8), or a pro-audio (studio) console. All these have different voltage ranges, whether fixed (like the 1v iPod or 2v CDPlayer) or voltage ranges - my car's Pioneer receiver can do up to 6volts while my Alpine goes up to 2v.

 

Now, a correct gain structure does a few things. First, from a signal fidelity standpoint, it as much as possible prevents clipping as well as distortion, allowing both the incoming variable level signal and the gain on the amp to work together (it's less tricky with a fixed input signal, since you only set one gain to match on the active speaker, but personally it's a pain in the ass if the knobs are on the amp installed at the rear of the cabinet.) The other thing is for convenience - you should only be manipulating one knob when you want lower volume. If for example you go from a normal gain Mahler recording to the Red Hot Chili Peppers' high-gain Californication,* then ideally you should be able to lower the volume on the preamp (since it's the one closer to you). Get the gain structure wrong, and you'd have to reset them again and again, because while you can dial down the volume to your comfortable listening level, dynamics can get too compressed or you get hissing in the background if one of them is set too high.

 

A general, quickie way we used to do it in car audio was to set the receiver's/head unit's volume to 3/4, then increase the amp gain until we hear clipping, then dial it back down to a cleaner level. Those competing for SQ events might whip out more sophisticated measuring equipment even just for the gain, but that's where it all starts, especially when you have a different speaker type handling a limited frequency range each pair of which has its own stereo amp (or mono on the sub.) Get this wrong and when you change the volume, the frequency response can have a drastically difference balance -  the most usual result being the high frequencies might get too loud compared to the rest at lower or higher volume.

 

 

*Given this extreme example though I actually just lower the gain on the media player if I'm listening from my computer

post #7 of 9
Thread Starter 
Quote:
Originally Posted by ProtegeManiac View Post


 

Well ideally you should get speakers that match the upstream components, but what I was talking about was for convenience and will apply to nearly any powered speaker or poweramp (with variable gain) and passive speaker. Think of it all this way: a passive speaker will have a gain knob, while most headphone amps have a gain switch. They're not exactly the same throughout but just to illustrate what they're for, the switch on amp lets you use normal gain on an efficient, low-impedance Grado SR325 and switch to high-gain for an efficient, but 300ohm Sennheiser or 64ohm, low-efficiency AKG. The variable gain however lets your speakers work with a wider range of possible sources - it could be an iPod through the earphone out, or the fixed 1-volt line out; or a CD Player with a fixed 2v line out; or a preamp output from a CD Player with an integrated variable output (like a Marantz), an integrated (head)amp (like a Musical Fidelity X-Can V8), or a pro-audio (studio) console. All these have different voltage ranges, whether fixed (like the 1v iPod or 2v CDPlayer) or voltage ranges - my car's Pioneer receiver can do up to 6volts while my Alpine goes up to 2v.

 

Now, a correct gain structure does a few things. First, from a signal fidelity standpoint, it as much as possible prevents clipping as well as distortion, allowing both the incoming variable level signal and the gain on the amp to work together (it's less tricky with a fixed input signal, since you only set one gain to match on the active speaker, but personally it's a pain in the ass if the knobs are on the amp installed at the rear of the cabinet.) The other thing is for convenience - you should only be manipulating one knob when you want lower volume. If for example you go from a normal gain Mahler recording to the Red Hot Chili Peppers' high-gain Californication,* then ideally you should be able to lower the volume on the preamp (since it's the one closer to you). Get the gain structure wrong, and you'd have to reset them again and again, because while you can dial down the volume to your comfortable listening level, dynamics can get too compressed or you get hissing in the background if one of them is set too high.

 

A general, quickie way we used to do it in car audio was to set the receiver's/head unit's volume to 3/4, then increase the amp gain until we hear clipping, then dial it back down to a cleaner level. Those competing for SQ events might whip out more sophisticated measuring equipment even just for the gain, but that's where it all starts, especially when you have a different speaker type handling a limited frequency range each pair of which has its own stereo amp (or mono on the sub.) Get this wrong and when you change the volume, the frequency response can have a drastically difference balance -  the most usual result being the high frequencies might get too loud compared to the rest at lower or higher volume.

 

 

*Given this extreme example though I actually just lower the gain on the media player if I'm listening from my computer


Very informative.  Thank you for this post.  I've learned a lot from reading this.

 

One quick question on this:

 

"Given this extreme example though I actually just lower the gain on the media player if I'm listening from my computer"

 

When listening from computer/itunes (computer > dac/amp > headphones), Ive been told that the volume level on the computer should be set to max (100%) and then the volume output should be controlled using the dac/amp.  Do you agree with this or are you saying that the computer volume level should be lowered (less than 100%)?

 

 

 

post #8 of 9
Quote:
Originally Posted by curtisinoc View Post


Very informative.  Thank you for this post.  I've learned a lot from reading this.

 

One quick question on this:

 

"Given this extreme example though I actually just lower the gain on the media player if I'm listening from my computer"

 

When listening from computer/itunes (computer > dac/amp > headphones), Ive been told that the volume level on the computer should be set to max (100%) and then the volume output should be controlled using the dac/amp.  Do you agree with this or are you saying that the computer volume level should be lowered (less than 100%)?

 

 

 


Yes it should be 100%; but what I meant by 'extreme example' was that Californication is recorded too loud to begin with. I'm not even sure if it's my ears that can't take it or the hardware was already clipping/distorting. I should have set it when I ripped it, but I rarely listen to it anyway and never got around to tweaking it (although I don't think any of the issues will be completely remedied either way), but when my entire library is on Shuffle switching from Mahler to RHCP could jolt me awake.

 

Other albums are noticeably louder, but not bad, usually just needs a notch less on the preamp/amp volume. Example would be my Epica CDs - the first two albums sound fine, the third's a little louder, then the fourth is a little louder than that. Even if I don't adjust the volume setting I don't hear distortion anyway. Another are my Nightwish CDs; the first three albums sound fine gain-wise, but the first album is just horrible on the dynamics, the re-mix versions of the songs and live recordings in later EP's sound a lot better; the fourth album on the other hand is louder, then the fifth a little louder. I might get the box set though, since it has the remastered first album, and I've scratched up my copy of Once because I used it in the car when my Alpine CD player stopped reading CD-Rs. Kamelot was doing fine and the slight increase in volume on Black Halo might just be me.

 

Read up on it here, I think I only own one that's unbearable, but there are others: http://en.wikipedia.org/wiki/Loudness_war#Criticism

 

post #9 of 9

definitely not your ears, I did a whole paper on the "loudness war" and Californication is one of top offenders heh.  

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › NuForce Icon HDP question . .