First-time poster with questions for audiophiles -- Car audio related

[Razor1973]

My first post here. I registered in order to ask this, as a matter of fact.

I'd like to describe a problem I'm having with my car audio and I'd like to know if there's a technical term for this. I am planning to go back to the car forums I frequent for my car make and ask if other people with the same system are having the same issues. I just don't know what this is called, especially because English is not my first language.

The effect I'm talking about feels as a VERY low bass. So low, it's irritating and when loud, it sort of overwhelms your ears and you can't hear anything else. I am getting it from my stereo when I have a bass rich song, but you can also get a similar sound in a car when only one of the rear windows is open or when you open a moonroof and pull down that piece of plastic in the front edge of the frame that's there to avoid this type of noise inside the cabin.

If you already know what I mean, can you tell me what could cause this in a car stereo system?

I don't think this is very relevant, but this is a new car equipped with a premium Dynaudio system, which most reviewers (car reviewers, not audio reviewers) have absolutely loved.

Thanks a lot in advance and I hope the way I've described this is sufficient for audiophiles to know what I am talking about. Feel free to ask any questions.

 

[Tech HiFi]

Does it happen when you are driving, standing still, or both? My guess is that either way you need your car audio system's freq. response adjusted using some type of installed equalizer. You can get pretty close using a SPL meter from Radio Shack and a CD with test tones or you can pay a professional to do it with a spectrum analyzer.

 

[Razor1973]

I haven't tried this while the car is standing still. But do you know the sounds I am describing? Think of driving over 50 mpg with one rear window open. It's the same sound. I'd actually describe it more as an effect, since it's more than just sound. The frequency is quite bothersome.

The radio does come with a rudimentary equalizer with 4-5 frequency ranges.

SPL Meter? This is the only thing I found on RadioShack.com. Will this do? I hope it comes with instructions, since I'd have no idea what I'm doing. I'm pretty handy and into gadgets, though.

Thanks.

 

[mtrycrafts]

My first post here. I registered in order to ask this, as a matter of fact.

I'd like to describe a problem I'm having with my car audio and I'd like to know if there's a technical term for this. I am planning to go back to the car forums I frequent for my car make and ask if other people with the same system are having the same issues. I just don't know what this is called, especially because English is not my first language.

The effect I'm talking about feels as a VERY low bass. So low, it's irritating and when loud, it sort of overwhelms your ears and you can't hear anything else. I am getting it from my stereo when I have a bass rich song, but you can also get a similar sound in a car when only one of the rear windows is open or when you open a moonroof and pull down that piece of plastic in the front edge of the frame that's there to avoid this type of noise inside the cabin.

If you already know what I mean, can you tell me what could cause this in a car stereo system?

I don't think this is very relevant, but this is a new car equipped with a premium Dynaudio system, which most reviewers (car reviewers, not audio reviewers) have absolutely loved.

Thanks a lot in advance and I hope the way I've described this is sufficient for audiophiles to know what I am talking about. Feel free to ask any questions.

I gather that your audio setup is stock and standard with that car?
Have you tried lowering the bass boost on the radio?

 

[Razor1973]

Yes, it is standard. This is the system. My bass is 3 bars under the center. My treble is one bar from the highest one.

Do you adhere to the idea of purchasing the SPL meter thinking this could help?

 

[Tech HiFi]

This is strange???? There is no way a stock audio system could generate the effect I'm thinking of. The SPL Meter will not help you. I would bring it to the dealer or contact the manufacturer of the audio system.

 

[Razor1973]

Does that effect have a name? How could I describe it in less words and/or more accurately?

 

[kenhoeve]

Let me guess, 2008 S80? Very nice system for stock.

What you are describing is not a well known phenomenon that would be familiar jargon between enthusiasts, unless of course we were gushing over the 90 db 17hz that our DD18 puts out during U571.

If this is happening during bass heavy tracks only, and it is annoying, then there must be some level of distortion going on. The other thing is you really don't know for sure what frequency this is that is bothering you. The SPL meter would be useful for figuring that out.

Personally, if it is that noticeable then I would just go back to the dealer and have them do just that, deal.

 

[mtrycrafts]

... The SPL meter would be useful for figuring that out. .

SPL meter doesn't show frequency, just intensity. A test disk might help in identifying the frequency but that would also need a special disc with selectable frequencies in the low band, most of them.

 

[mtrycrafts]

Yes, it is standard. This is the system. My bass is 3 bars under the center. My treble is one bar from the highest one.

Do you adhere to the idea of purchasing the SPL meter thinking this could help?

I would not recommend an SPL meter as it doesn't tell you the frequency, just level in spl.
I would suggest you doing some experimentation. Find the CD that brings out this condition. Test it when the engine is off, or just idling, and of course parked see if can be reproduced. Also, reset the treble for these tests to the middle just to be on the safe side. Or, vary it at the passages; same with the bass boost and cut. Set it all the way down. and up, see what happens.

Also, how many CDs do this with bass content? Are all these commercial CDs or copies that may have been remastered on the way?

It almost sounds like a low frequency constant feedback or oscillation. Perhaps a car part is resonating and reinforcing this condition? That is why this needs experimentation to isolate its specific condition that will happen under and not others perhaps. Any warranty on it left?

 

[Razor1973]

Let me guess, 2008 S80? Very nice system for stock.

2007. Same system. Yes, it's supposed to be very nice.

Personally, if it is that noticeable then I would just go back to the dealer and have them do just that, deal.

I think I will do that. It's just difficult to show something like this to them. They don't feel a very noticeable problem I have with what seems to be my transmission. It will be even more difficult for them to hear this audio problem.

I would suggest you doing some experimentation.

I will do everything you suggest here.

Also, how many CDs do this with bass content? Are all these commercial CDs or copies that may have been remastered on the way?

This does happen mostly with burnt CD's, but it has happened with 1 or 2 original CD's too.

Perhaps a car part is resonating and reinforcing this condition?

This actually is the case and is causing another problem that sounds like a cracked speaker or rattle inside the door panel, but the effect I am referring to here is not located in a specific section of the interior. It's all over. A friend suggests it could be a blown sub-woofer. It sort of makes sense.

Any warranty on it left?

Tons. I just got the car 2 weeks ago.

 

[mtrycrafts]

I think I will do that. It's just difficult to show something like this to them. They don't feel a very noticeable problem I have with what seems to be my transmission. It will be even more difficult for them to hear this audio problem.

More reason to try and isolate the issue yourself but without voiding the warranty.

This does happen mostly with burnt CD's, but it has happened with 1 or 2 original CD's too.

Then, you may want to play those CDs on another system and see if anything shows up, trying to play at a similar level you used in the car.

This actually is the case and is causing another problem that sounds like a cracked speaker or rattle inside the door panel, but the effect I am referring to here is not located in a specific section of the interior. It's all over. A friend suggests it could be a blown sub-woofer. It sort of makes sense.

If you are careful and able, you may be able to pull the grill without pulling the door panel to see if the cone is visibly damaged or not. A low frequency resonance may be perceived as coming from all over, or at least the low frequency part of it will.

Is the sub mounted in the door or elsewhere? Doors have lots of parts that could be resonating some.

Just thought of another troubleshooting tip. Have a friend sit near the sub and if he hears that noise or if not tell him when, place his hands near the sub area pressing on car parts that is accessible to him to see if any of the hand dampening makes it disappear?

 

[Razor1973]

Then, you may want to play those CDs on another system and see if anything shows up, trying to play at a similar level you used in the car.

These are the same CD's I was playing in my previous Volvo which also had a Dolby Prologic II surround system, just not by Dynaudio. I could crank the volume to the max and no problem.

Is the sub mounted in the door or elsewhere?

Apparently. This is extracted from the Dynaudio S80 page (or click to go to the page for more details and photos if you prefer):

"Each front door houses a sophisticated three-way loudspeaker system consisting of a woofer utilising a powerful motor structure with high power handling for exceptional low frequency reproduction, while the extraordinarily large dome mid-range speaker, featuring a special coated soft-dome, provides crystal-clear clarity for the midrange so vital for intelligibility of vocals. A tweeter with a smaller coated soft-dome, delivering accurate treble reproduction resolving even the subtlest of nuances, augments each of these speaker arrangements. As part of a true Surround Sound System, the S80 comes equipped with a dedicated Dynaudio Center channel loudspeaker system integrated into the dashboard and a speaker system in both rear doors, each of these employing equally sophisticated woofers and tweeters. The Dolby Pro Logic II™ digital Surround processor technology and unprecedented powerful digital amplification, totaling 650 Watts, serve to ensure the ultimate sound experience.

... the bass woofers are equipped with the company’s proprietary extremely light yet incredibly rigid Magnesium Silicate Polymer cone diaphragms. In addition, unique, ultra-light aluminium voice-coils are utilised for increased power handling. The highly refined midrange speakers and tweeters feature a gently curved and carefully coated fabric dome. Not that any of this advanced technology can readily be seen – but within the very first moment of listening to music it becomes very apparent."

I will try and play some more with the stereo and the suggestions you gave me and will come back and report.

Thanks a whole lot!

 

[mtrycrafts]

These are the same CD's I was playing in my previous Volvo which also had a Dolby Prologic II surround system, just not by Dynaudio. I could crank the volume to the max and no problem.


Apparently. This is extracted from the Dynaudio S80 page (or click to go to the page for more details and photos if you prefer):

"Each front door houses a sophisticated three-way loudspeaker system consisting of a woofer utilising a powerful motor structure with high power handling for exceptional low frequency reproduction, while the extraordinarily large dome mid-range speaker, featuring a special coated soft-dome, provides crystal-clear clarity for the midrange so vital for intelligibility of vocals. A tweeter with a smaller coated soft-dome, delivering accurate treble reproduction resolving even the subtlest of nuances, augments each of these speaker arrangements. As part of a true Surround Sound System, the S80 comes equipped with a dedicated Dynaudio Center channel loudspeaker system integrated into the dashboard and a speaker system in both rear doors, each of these employing equally sophisticated woofers and tweeters. The Dolby Pro Logic II™ digital Surround processor technology and unprecedented powerful digital amplification, totaling 650 Watts, serve to ensure the ultimate sound experience.

... the bass woofers are equipped with the company’s proprietary extremely light yet incredibly rigid Magnesium Silicate Polymer cone diaphragms. In addition, unique, ultra-light aluminium voice-coils are utilised for increased power handling. The highly refined midrange speakers and tweeters feature a gently curved and carefully coated fabric dome. Not that any of this advanced technology can readily be seen – but within the very first moment of listening to music it becomes very apparent."

I will try and play some more with the stereo and the suggestions you gave me and will come back and report.

Thanks a whole lot!

And, in the mean time, since those CDs were played before with no issues, that should not be the cause.
One more to check though. Were you playing the Cds in stereo mode or DPLII? If the latter, try it stereo and see.
It also seems that there are 4 door mounted speakers that may need to be checked.
Perhaps calling the Volvo customer service center, not your dealer but the national, and see if you can talk to someone there; it is a long shot.