Jump to content

 

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Sign in to follow this  
flapjack

Power consumption vs. volume knob

Recommended Posts

flapjack

Stoopid question...

Which uses more power assuming the same amount of sound from the speakers? Is running in one mode "hard" on the system?

a)

ipod volume = 2

stereo volume = 8

sound coming from speakers = X decibels (same as B)

-or-

b)

ipod volume = 8

stereo volume = 2

sound coming from speakers = x decibels (same as A)

Share this post


Link to post
Share on other sites
FastFreddy

Same thing.

However you're making me think

Head unit volume = 20

Amp gain = MAX

Head unit volume = 30

Amp gain = 50%

Which one uses more power based on same speaker volume?

I'm willing to bet $ it's the same too.

Share this post


Link to post
Share on other sites
Earmark Marine

You might have the same output power with either scenario.

But you won't have the same sound quality.

Low voltage at the source creates a need for more voltage from a gain stage down line in the signal path. And that encourages a higher noise floor. So you want as much gain as possible at the beginning of the signal path.

But there is a window.

You don't want any signal compression or distortion coming from the source that would be conducted by every component downstream. So the output of the source must be clean.

Unfortunately, an ipod has very low output voltage.

Whether by ear or by a test instrument, like a handheld scope, you want to determine the maximum clean (non-clipped) output from the ipod. That will be the fixed level that you should always run at.

The head unit will make the volume changes.

David

Share this post


Link to post
Share on other sites
augie09

you're running using the ipod port and not the ipod headphone jack right? Think the headphone jack will introduce noise.

Share this post


Link to post
Share on other sites
flapjack

You might have the same output power with either scenario.

But you won't have the same sound quality.

Low voltage at the source creates a need for more voltage from a gain stage down line in the signal path. And that encourages a higher noise floor. So you want as much gain as possible at the beginning of the signal path.

But there is a window.

You don't want any signal compression or distortion coming from the source that would be conducted by every component downstream. So the output of the source must be clean.

Unfortunately, an ipod has very low output voltage.

Whether by ear or by a test instrument, like a handheld scope, you want to determine the maximum clean (non-clipped) output from the ipod. That will be the fixed level that you should always run at.

The head unit will make the volume changes.

David

Thank you for your answers. For the same output power (at the speakers), do both consume the same amount of power (and generate the same heat)?

you're running using the ipod port and not the ipod headphone jack right? Think the headphone jack will introduce noise.

Thanks for the feedback. In my hypothetical, I'm intentionally leaving the stock RF out of the equation.

Share this post


Link to post
Share on other sites
Earmark Marine

Thank you for your answers. For the same output power (at the speakers), do both consume the same amount of power (and generate the same heat)?

Same power, same efficiency, and same heat regardless. Different sound quality.

The ipod headphone jack is an unsophisticated amplifier intended for earbuds and extending battery life. The bandwidth is limited, particularly at the bottom end. You want to access the true preamp from the bottom port.

Sidenote. If you used nothing but lossless files and used an external DAC with your ipod, you would be shocked.

David

Share this post


Link to post
Share on other sites
wakesetter8796

Thank you for your answers. For the same output power (at the speakers), do both consume the same amount of power (and generate the same heat)? Same power, same efficiency, and same heat regardless. Different sound quality.The ipod headphone jack is an unsophisticated amplifier intended for earbuds and extending battery life. The bandwidth is limited, particularly at the bottom end. You want to access the true preamp from the bottom port.Sidenote. If you used nothing but lossless files and used an external DAC with your ipod, you would be shocked.David

So using the headphone jack and a cable is not a good solution for sound quality?

Share this post


Link to post
Share on other sites
MLA

So using the headphone jack and a cable is not a good solution for sound quality?

Its the lowest SQ.

Share this post


Link to post
Share on other sites
wakesetter8796

How would I play the iPhone 5? USB?

Share this post


Link to post
Share on other sites
Nitrousbird

How would I play the iPhone 5? USB?

30 to 8 pin adapter (genuine Apple one). They work.

Share this post


Link to post
Share on other sites
nyryan2001

Its the lowest SQ.

Lower SQ than wireless Bluetooth?

Share this post


Link to post
Share on other sites
Earmark Marine

Lower SQ than wireless Bluetooth?

I guess it would depend on the particular piece of BT equipment and quality of downloads you are comparing to.

I know this. In a quiet vehcile with a good system and good source material the BT compression is definitely audible. In a boat, not so much?

It would be easy to download pink noise or any number of refences and look at an RTA to at least check the bandwidth. But I know in the case of the phone jack there is a reduction in bandwidth. After all, they didn't expect earbuds to play low. And I wouldn't be surprised to see Class B used on a headphone out to conserve energy.

David

Share this post


Link to post
Share on other sites
wakesetter8796

How would I play the iPhone 5? USB?

30 to 8 pin adapter (genuine Apple one). They work.

So iphone to 8, 8 to 30, 30 to USB?

Share this post


Link to post
Share on other sites
MLA

Lower SQ than wireless Bluetooth?

Tough call. I've heard some poor BT receivers and some decent ones. Most of the decent ones seem to have good quality as long as the range is close, but begins to fall off quickly as you move away. The BT transmitters in phones seem to be ok SQ as long as the phones volume level is no more then half. After that, the quality falls off quickly. Using the 3.5mm is about the same, but the BT seems to fall off at a steeper rate. So its a compromise which ever route you go. If you want the wireless convenience, you need to be willing to live with a little lower quality in some circumstances. Id you can live with being wired, then I would look to going from the data port, then use the 3.5mm as a secondary means.

I also have experienced some good and poor 3.5mm outputs. I have a 2nd GEN nano from 2005. Its only needed a battery and a screen (our fault) and is still functional. Jan of 2012, right before the boat show, I added some Ipod specific gear to the display and discovered it would not work with the old Nano. I sent the wife out to pick up a new one. I told to just get a mid level one as it was just going to be used on the display. Short story long, its sound quality out of the 3.5 is absolutely garbage compared to the 7 year old Gen 2 nano. Most of the cell phones seem to have a decent 3.5MM output as well as the larger Ipods, Zunes and Zens. So, the MP3 one is using has as much to do with the SQ as the rest of the gear.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...