Mark, since same radio is used for premium and standard, only premium has an external amplifier, fader is controlled by radio not head unit.

John

 

Thank you, now I'm more confused. Isn't the head unit the piece of equipment in the dash containing the radio and all the controls? It's all one device, correct?
I also found Friday the SW (sub woofer) control and is active on my premium system without sub woofers, only woofers.
and I found a POS control sets to All, F right or F left. It is active and sounds best on either setting R or L. All sounds worse. Do you know whst thst adjustment does? It doesn't seem to eliminate either side.
Thank you Mark

 

Hi Mark,

Do you have factory (stock) radio in the dash? Assuming yes.

Some info:
If the car was purchased with standard stereo option, the switch on the back of the radio would be set to standard (position).

All speakers that standard stereo uses will be connected directly to radio.

As I recall, standard stereo option does not use some drivers (a synonym for speaker), tweeters in the "sail" or triangular space front of front window are not used.

Since the radio is connected to the drivers, there is an amplifier inside the radio.

When you press Mode button, radio cycles between 4 options for you to adjust to your tastes:
Bass - boosts or attenuates low frequencies.
Treble - boost or attenuate high frequencies
Balance (Bal) - attenuates either the left or the right channel making the non attenuated channel sound louder. IOW shifting the balance to the right, doesn't make the right channel louder, it makes the left channel less loud. This setting treats Front and Rear speakers as identically.

Example: you press Mode, select Balance, shift the balance to the right so that right channel sounds twice as loud as left. What happens? The Balance control attenuated the signal to all the speakers on the left channel 50%.

Fade - apparently moves the sound forward (front), or rearward (rear) by attenuation the sound in all front or all rear speakers (both left and right channels simultaneously). Want to move the sound to the front? Use fader to "increase" Front level - you're really attenuating or decreasing the signal to rear left and rear right speakers simultaneously.

Mark all of this processing occurs in the pre-amp section before the signal is amplified enough to drive the speakers.

__________________
Got the Premium system?
Switch on back of radio is set to Premium.

Processed signal is sent directly from radio's preamp to the amplifier in the trunk.

Mark I think you mentioned subwoofer as though there is a selection for this on your radio. That's why I asked if you have a stock radio - my Premium stock system has no such option.

This may help us all synch up:

Subwoofer is a term to describe a driver that will reproduce only the lowest frequencies. It is typically connected to its own amplifier. This amplifier is connected to a low pass active crossover that only allows the lowest frequencies to go to the subwoofer amplifier. Typically 20hz to something between 60hz and 150hz (the bandwidth of the subwoofer can usually be selected at the preamp level).

If you're using a subwoofer, you should be using a high pass crossover to send all the higher frequency signals to the other speakers. Matching the -3db points of the low pass and the high pass crossovers should provide a flat response.

Woofer
This term is given to drivers designed to produce low frequencies, but with a much wider bandwidth than the subwoofer. Typically the woofer is an integral part of the full range speaker system. It is driven by the same amplifier that drives midrange and tweeters. BTW, in a well designed speaker system subwoofers augment woofers, they don't replace them.

Mark, you probably knew most of this already, but I hope it helps you get a handle on what you're dealing with, and can help you focus on what's wrong so we can help you.

John

 

Hi John,
I have determined I have the premium sound. I have the head in dash with cassette, all the adjustments, volume, mode...The mode has all the standard plus an active SW Sub Woofer selection it audibly works, plus a POS active selection with All, Fright and Fleft. Each selection sounds different but does not exclude either side. The All selection is the least desirable sound. Either of the other 2 produce a better sound.
It has door speakers and dash speakers. It has the now infamous side rear speakers mounted in the enclosed boxes, no rear tweeters. The rear speakers are woofers, not sub woofers.
Amplifier and CD changer in a rack under the hydraulic device for the convertible top on the passenger side in the trunk. That is my knowledge of my system. I am assuming it does not need a code to reactivate it following power loss as it was made for US and I'm told they dont require a code.
It sure feels like a contradiction having an active Subwoofer adjustment with no Sub Woofer.
Do you know whst the POS adjuster does?
Today the speaker box on rear passenger side has started to vibrate against the metal frame. All mounting screws are tight, so now we have a new issue. Any insight on how to fix that very annoying plastic metal vibration.
That's what my system is. Anything else, crossovers or head buttons I dont know.
Mark



---------- Forwarded message ----------
From: Mark Marlow <beachmark9@gmail.com>
To: Jaguar Forums - Jaguar Enthusiasts Forum <noreply@jaguarforums.com>
Cc:
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Date: Sat, 11 Sep 2021 22:48:02 -0400
Subject: Re: Reply to thread 'Rear Speakers test? XK8 rag top'
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Mark, what kind of radio do you have? Any chance you could post a photo?

John

 

Certainly here it is


passenger speaker and radio

 

Certainly here it is


passenger speaker and radio

 

Ok same as mine. Please tell me how you access the sub woofer selection?

I see POS in your notes and think "piece of ****" is that what you mean by it?

John

 

POSITION

 

Though the faceplate is the same, the system, system operation, and the mode controls are different between 1998 MY and 2000-2002 MYs. That is very important in comparing the behavior of the mode switch and rear speakers, they behave differently by design between 2000-2002 and earlier.

A snippet of the audio manual is shown below. The S.W (subwoofers) in the back is a new behavior for the rear speakers (the only speakers in the back, they act like subwoofers here, they are subwoofers here, there are no others).; POS is programmed delays designed to stage the sound to the driver, to the passenger, or to 'all'.

Note, SW +7 gets pretty 'thumpy'.

As noted earlier, fade is turned off by default in the 2000-2002 MYs. It's clear that they were concerned that the change in operation/design of the rear speakers to subwoofers would be misinterpreted by users if they faded all the way to the year. They also put out an Audio Supplement in 2001 directly addressing this concern that the rear speakers only put out low frequencies, and they put out a TSB addressing the same concern.


2000-2002 Mode controls - Premium. Different than the mode controls before 2000. The system has different design principles and different behavior than for earlier models.

 

under mode is the POS. Yes I did think of p.o.****.

 

How to access Selective Tone Memory? Is that one of the other buttons I dont know what they do? Lol
POS = Left, right or ALL. what ALL LOL the dog in the "back Seat" ? ALL that's funny.

 

How to access Selective Tone Memory? Is that one of the other buttons I dont know what they do? Lol
POS = Left, right or ALL. what ALL LOL the dog in the "back Seat" ? ALL that's funny.

 

After all the help from many, it was definitely the Amplifier that had gone bad in the back. Now I have to decide if I want to upgrade the speakers. Thank everyone who helped along the way.
Mark
still not sure why I dont have tweeters in the back on the sides, with premium, but all good.