No bass output from Laptop

[Keladrin]

Hi. I'm new to REW
, using a Dell Latitude 7290 laptop running Windows 10 with Realtek Audio selected as the output (Java). but I am getting zero to now bass output below around 200Hz. Bass is around 40 db down in measurement curves, regardless of what I am measuring and proximity of USB mic (which has been calibrated). I have tried various preference setting to no avail. The output above 200Hz looks realistic but below this falls off rapidly then strangely starts to rise again below 10hz. I know my room has a 40hz resonance but am seeing at least 50db down at this frequency. Can't hear any low frequencies in the freq sweep at all. Is it the soundcard?

 

[John Mulcahy]

What is the output connected to?

 

[Keladrin]

Connected to a Cambridge Audio A1 MK3 amp via headphone socket on laptop to phono in. I've tried 2 amps actually, same results.

 

[Kal Rubinson]

Connected to a Cambridge Audio A1 MK3 amp via headphone socket on laptop to phono in. I've tried 2 amps actually, same results.

Don't use phono input! It incorporates unnecessary gain and wildly inappropriate EQ for your application. Don't you have another "line level" input available?

 

[John Mulcahy]

I suspect 'phono' may just mean what you'd call an RCA connector, Kal, I don't think that amp has inputs for MC/MM cartridges.

You can plug some headphones in to check what is being produced. If there is no low end some things to check are the sweep start frequency and whether any audio 'enhancements' are being applied to the headphone output. If you look on the Enhancements tab of the Windows audio properties for the output you are using there should be a check box to disable all enhancements.

 

[ddude003]

The documents I saw on this amp suggest that there may or may not be an actual phono stage in the amp... If it has NO phono stage the docs suggest it is a line-level input... If there is an included phono stage then obey Kal... To be sure one way or another try the CD input...

By the way, what speakers are you using?

 

[Kal Rubinson]

I suspect 'phono' may just mean what you'd call an RCA connector, Kal, I don't think that amp has inputs for MC/MM cartridges

The documents I saw on this amp suggest that there may or may not be an actual phono stage in the amp... If it has NO phono stage the docs suggest it is a line-level input... If there is an included phono stage then obey Kal... To be sure one way or another try the CD input...

I checked and the answer is that it does not have a phono input but it has one that is stupidly labeled "Aux/Phono." So, that is probably not the problem although I agree that trying another input, just to see.

 

[Keladrin]

Hi Guys. Yes I meant the connector type is phono.
Tried various amplifier inputs. I think the problem might reside in the soundcard and it does not have any enhancements applied. Will have to try another laptop I think.

 

[Keladrin]

Tried an SPL meter just to confirm it was not mic related - DB about 40 down starting from 200Hz and lower. Even put the meter at the speaker port output, tuned to 30Hz and virtually nothing at 30Hz. I am hearing nothing as well. Definitely the Laptop/soundcard. Will have to borrow another one I think. The speakers are rated at 25hz - 3db and have really good bass output. Same issue with headphones and computer speakers/woofer. Most annoying!

 

[Keladrin]

Did some online research and it appears its a common issue with laptops. The driver mutes the bass output to prevent the internal speakers being overloaded. The trouble is there does not appear to be any way of turning this off. Tried updating the audio driver and it actually seemed to work for a few seconds then the bass must kicked in and back to normal. Any ideas?

 

[John Mulcahy]

In principle it should be possible to disable it by disabling enhancements on the headphone output's audio properties. It shouldn't really be applied when something is plugged into the headphone jack though, since that should disconnect the internal speakers.

 

[Keladrin]

OK but there does not appear to be this option. There is nothing to click or disable.

 

[John Mulcahy]

Is there an enhancements tab on the Audio properties? There also used to be a place where you could tell Windows what kind of speakers were connected, though it may no longer exist. When I plug anything into the headphone output on my PC a dialog appears asking what kind of device has been connected (headphones, external speakers (small/large)), presumably from the Realtek driver.

 

[John Mulcahy]

Looks like the prompt I get is from Waves MaxxAudioPro, preinstalled on the PC. There is a selector in the playback section to turn its features off.

 

[thothsong]

There also used to be a place where you could tell Windows what kind of speakers were connected, though it may no longer exist.

In the Sound Control Panel, when you use Configure Speakers, you can select which speakers are full-range, if that's what you mean.

 

[Keladrin]

Update. The Dell engineer came and replaced the motherboard and updated the BIOS. We also looked at all the software settings including AudioPro (above). In short nothing worked. The latter would boost the bass a bit but, if disabled, bass cuts off completely at 60Hz. Even with it turned fully up with the MaxBass control I am hearing very little bass (and it measures well down) and what is there is rather distorted. Just as a check I plugged in a calibrated sound generator into the amplifier and this gave full bass as expected. Laptop pretty useless for doing any serious measurements! I will try and install REW on my old PC but this is rather old and still running Windows WP. I don't know it is compatible? I tried installing it a while ago but it would not open.

 

[ddude003]

I would not expect a headphone out / speaker out to work very well when wired directly into the input of a power amplifier... Does anyone know the voltage and ohm spec for that output port in the laptop? This isn't line level out is it? And the amp will want line level in, yea? All I can find is that it is 2 watts... Sounds like a sensitivity or gain structure issue to me... I don't suppose there is a preamplifier mode you can drive that sound card in...

 

[Keladrin]

OK I have managed to install REW on my old desktop, wired everything up and no problem at all with bass levels. Headphone output used here as well. So beware of Dell laptops. Done some great measurement curves.

 

[Tim Dawson]

USB sound device on the Dell, and ignore the internal parts?