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        General >> Problems >> Loss of bass at volume
        
(Message started by: BrianT on May 21^st, 2004, 4:38pm)

Title: Loss of bass at volume
Post by BrianT on May 21^st, 2004, 4:38pm

On the 7000rds stereo, I notice that at higher volumes, with the bass set fairly high (over 3), the bass response seems to "cut out", especially noticeable on rock or dance music tracks. It doesn't disappear, but seems to suddenly fade, at very "bass-ey" sections, then return to normal. Anyone else noticed this?

Title: Re: Loss of bass at volume
Post by howiedintheplace on May 21^st, 2004, 5:20pm

BrianT

Possibly speakers out of phase or maybe the main live feed blown so it's running off the permanent feed but not all stereo's can do that. Is there any distortion when it happens & is all the speakers standard.

Title: Re: Loss of bass at volume
Post by Badboytunes on May 21^st, 2004, 7:12pm

Hi m8 , there are 2 reasons for this. Firstly the 5/6/7000 series has a "clip" funtion on it to cut the lower frequency at high volumes. This is to stop the speaker from distorting. The second reason is that the radio will loose the ability to produce low frequencies at high volumes as the unit has a low power rating alongside the speakers. An upgrade is the answer but check the "clip" funtion first.

Cheers Nick ;)

Title: Re: Loss of bass at volume
Post by howiedintheplace on May 21^st, 2004, 7:52pm

Spot on Badboytunes
I forgot all about the "clip" funtion. Sounds a sure thing to me.

Title: Re: Loss of bass at volume
Post by Badboytunes on May 21^st, 2004, 8:38pm

Cheers

Title: Re: Loss of bass at volume
Post by DJWerkz on May 22^nd, 2004, 9:56am

BadBoy is more or less spot on,...many standard car radios lose the lower frequencies at higher volume, you may even notice other symptoms such as flickering or dimming display.
The main reason is that the radio is not designed to drive at high-volume. Problem is really down to the fact that the amplification circuitry is not up to the job and the 12v power supply will also struggle to feed enough power to power an amplifier with a sufficient clean supply.
You may have noticed with some of the more developed ICE packages that owners will use a large cylinder capacitor which stores dc power so that the equipment is not solely reliant on the car battery.
You will just have to opt to leave your 'Bass Invaders' CD at home!!! :)

Title: Re: Loss of bass at volume
Post by JohnJ on May 22^nd, 2004, 8:39pm

Every one is right to a degree.....the system has a circuit inbuilt which can pick up bad responce from the Speakers "Distortion" as soon as it detects bad responce from the speakers it cuts low frequency from the output resulting in a lack of bass.

Bad responce from a Speaker can cause a standing wave on the speaker output wire...this creates a EMF "electro magnetic force" which can be read by a meter.....but is built in to the 7000 series and then automaticly cut bass.

I dont like it...it limits you listing pleasure.

JJ

Title: Re: Loss of bass at volume
Post by DJWerkz on May 22^nd, 2004, 8:50pm

Bad speaker (driver), response (distortion), is the result of poor amplifier and power (in this case DC) in car audio especially. It seems that the 7000 head-unit's in-built circuit protection is only there to control the units 'own' missing capabilities to drive a speaker in the first place.
This is exactly why you will never hear good 'music' in a car audio system and why heavily compressed formats such as mp3 sound ideal in car audio systems.
But then, if you have not heard a real 'musical' two-channel system then you would be inclined to think otherwise about in-car audio!

Title: Re: Loss of bass at volume
Post by DJWerkz on May 22^nd, 2004, 9:16pm

One thing I forgot to mention is that the basic problem does come back to the manufacturer putting together an audio system that is not only musically but highly likely an electrical mis-match.
Every audio system no matter what it's application centre's around being completely balanced (it is worth stating that even some systems that are matched perfectly electrically still sound bad - somethig that even electronic experts still have no explanation for).
Manufacturers match systems on the basis of,...how cheap can we build this but still give the customer the 'illusion' of great sound.
The problem comes when systems need to be driven hard, more volume creates more engery (heat), which the speaker's voice coil must be able to dissipate so that it does not heat up to the degree where it becomes too resistive to allow further current to flow through the coil.
It's the current flow through the coil that causes the cone to drive back and forth.
So to summarize, the head unit is at fault because it creates distrotion having poor amplifier capabilities and the speaker drivers themselves are at fault because of not being able to be driven hard!

Title: Re: Loss of bass at volume
Post by JohnJ on May 22^nd, 2004, 9:24pm

No...I'm not talking of poor amplifiers or anything like that......Ford actually did put these added features into the 7000 series to compensate for disstortion and I do agree that they should have spent a bit of money on better quailty speakers and amps but thats life.

Altimatly all amplifires for on 'DC'....Weather its in a car or in a house running on 230v...they use bridge rectifies and tranformers to get them down to 12 or 24v for...

Class A mosfet for 'true amplification' Domestic not efficiant and very power hungry.

Class B Push pull amps are very effiecnt but do not create a true representation of the waveform therefore not prefered by hifi buffs. But used in cars amps.

Title: Re: Loss of bass at volume
Post by DJWerkz on May 22^nd, 2004, 9:46pm

Regardless of amplifier class the amplifier still needs to be able to drive the load,...and in turn the load capable of efficiently handling the energy!
IMHO,...the whole protective circuitry is a classic case of bolting the stable door after the horse has bolted!
Like you say, Ford should have invested a little more time and money on developing the system properly in the first place.

Title: Re: Loss of bass at volume
Post by JohnJ on May 22^nd, 2004, 10:01pm

Exactly 100% agreed....they fix the bad noise created by bad speakers with more crap making the sound worse than what it was before..

I like the bolting horse explaination.

;) JJ