Sean DD + Harmon K amp

[HarryM1BYT]

I've just spent a good weeks worth of my odd bits of spare time on this, including lots of trips up the garden path, but the end result has certainly been well worth the effort....

I originally started with my Mk II 75, fitted with all of the separate bits of a Hi-Line system kit, including an Hardon Karmon amp and the 10x HK speaker system, including subs.

On installing a Sean DD, you disconnect 2x separate 8pin ISO plugs (a brown one and a gray one) from a combined twin 8 pin black ISO socket, behind the radio. The brown one feeds audio from the DD directly to the speakers. Its other half, the black socket is/was the output of the HK amp.

The gray 8 pin, which now feeds all of the supplies to the DD, originally was the main supply to feed the items in the boot - via its other half the black socket. Once that plug is unplugged, the HK amp will have no permanent 12v (purple/pink) and no ignition switched 12v (AKA the remote) (purple/yellow). [Edit] I also now have some sort of reception on AM, not good, but reception on the move. Previously it was complete noise, end to end.

For the 4x twisted pairs, for my initial tests, I decided to try to use network cabling. That proved itself to be NOT adequate and caused some terrible distortion. For my final install I used 0.5mm cable red and black, twisted together into wire pairs using a battery drill to put the twist in. Once installed and tested, that sounded fine.

The speaker pairs are as follows:-

Rear right - blk/grn blk/or
Front right - blk/purp blk/blu
Front left - blk/whi blk/slate
Rear left - blk/brn blk/red

For its audio input, the HK amp expects speaker level inputs, such as most standard radios would provide - including the DD. As originally wired by Rover, the input to the HK amp came directly from the radio module, mounted in the wheel well, with the HK amp mounted close to the fuel filler in the boot. The output from the HK ran to behind the radio, to the 2x 8 pin black ISO socket, then via the brown 8 pin plug to each door speaker.

To get the HK amp back into full working order is fairly simple and took around three hours of effort, in the freezing cold and the dark of my drive - once I had satisfied myself what was going on with the wiring of the original system.

Basically you need to run 4x pairs of speaker wires (8 in total) from the back of the DD, to the HK amp in the boot. Ideally these should be 4x twisted pairs, to prevent noise pick up. One pair used per channel, four channels - front left, front right, rear left, rear right.

At the front, if you happen to have a spare 8 pin brown ISO plug, they plug into the socket where the brown 8 pin ISO plug fits on the DD. The brown 8 pin is then plugged back into its original socket in the 2x 8 pin black socket. All you are doing is individually linking each colour of wire, to exactly the same colour of wire at both DD output and the HK amps input plug. The HK amp uses two plugs to connect it to the loom, the one with the fewer number of pins contains all of the speaker input wires. Be aware that EXACTLY the same colours of 8 wires is repeated on the output plug.

Now the easy bit, the power feeds need to be sorted out....

Behind the radio on the original Rover part of the loom, the gray 8 pin ISO plug has a purple/pink 12v permanent live and a purple/pink 12v switched 12v. These need to be individually linked across to the very same colours of wires, on the black twin 8pin ISO.

Basically all that was missing - was the speaker output of the DD needing to go to the HK amp in the boot, to feed it with audio. The output of the HK amp then goes to the front of the car emerging on the twin black ISO socket, so if the brown 8 pin ISO plug is plugged back in the amp will once again feed the speakers. Because th gray power feed plug has been unplugged from the twin black ISO plug to plug into the rear of the DD, you loose all feeds to items in the boot - so you link across the power between the plug and the socket (purple/pink and purple/yellow).

There - if anything seems unclear, please let me know.

Since writing this, something has occured to me....

The feed for the radio antenna amp in the back window is the Purple/yellow switched 12v. As part of trying to diagnose the poor reception of the Sean DD, I tested the purple/yellow to make sure it was live and it did seem to be. A quick check on the radio's reception last night, after getting the HK amp working, seemed to indicate that the reception was very much better than it had been previously, so I'm now wondering if when I checked that purple/yellow it might not have had a proper 12v feed going to it, that what I was seeing on the meter was just a bit of stray pick up. Until now, I have not been able to pick up Radio Aire FM - which is a fairly weak station to try to receive here anyway. After doing the HK amp circuit mods, Radio Aire FM became almost listenable. It might just have been reception conditions last night, but worth keeping in mind I think.

[petergw60]

Hi Harry,
Just received my new DDin unit from Sean and trying to fit into my Hi-line 75. I found your post very interesting and kept a copy in readiness for when I started to do mine!

Have removed the old head unit, radio, TV and nav computer. Looking at trying to get my HK amp working and read and re-read your post! So, a few questions!

You say we have to run pairs of wires from the DDin at the front to the rear. Did you connect in using the now empty plug removed from the radio for these wires at the rear?
At the front you mention a brown 8 pin ISO plug. This is where I am getting confused as I do not have a brown ISO plug. Have fitted the adaptor to the loom so that the supplied lead with the unit can attach to the DDin unit - but nowhere is there a brown ISO connector.

Adding power to the rear (the easy bit!).
You say behind the radio there is a grey 8 pin ISO plug - where exactly is this as cannot see one! There are the 12 pin blue and white connectors removed from the head unit and the steering wheel controls connector. Do you mean the remains of the plug which I unplugged to fit the adaptor (now hidden well out of site way down the bottom!).

Just a thought also on aerials. The diversity amp originally fed two feeds to the radio, one on a standard aerial type plug and one on an SMB type plug. If we were to extend both of these to the front, could we use one for the radio and one for TMC?

[HarryM1BYT]

Originally Posted by petergw60

Hi Harry,
Just received my new DDin unit from Sean and trying to fit into my Hi-line 75. I found your post very interesting and kept a copy in readiness for when I started to do mine!

Have removed the old head unit, radio, TV and nav computer. Looking at trying to get my HK amp working and read and re-read your post! So, a few questions!

You say we have to run pairs of wires from the DDin at the front to the rear. Did you connect in using the now empty plug removed from the radio for these wires at the rear?
At the front you mention a brown 8 pin ISO plug. This is where I am getting confused as I do not have a brown ISO plug. Have fitted the adaptor to the loom so that the supplied lead with the unit can attach to the DDin unit - but nowhere is there a brown ISO connector.

Adding power to the rear (the easy bit!).
You say behind the radio there is a grey 8 pin ISO plug - where exactly is this as cannot see one! There are the 12 pin blue and white connectors removed from the head unit and the steering wheel controls connector. Do you mean the remains of the plug which I unplugged to fit the adaptor (now hidden well out of site way down the bottom!).

Just a thought also on aerials. The diversity amp originally fed two feeds to the radio, one on a standard aerial type plug and one on an SMB type plug. If we were to extend both of these to the front, could we use one for the radio and one for TMC?

It sounds as if your Hi-Line install is very different to mine, so my instructions will not help you that much. Basically, you need to disconnect the link between DD at the front and the various speakers. You then need to connect all four speaker outputs from the DD back to the HK amp - hence the 4x pairs front to HK amp at the back. The output of the HK amp is already connected to the four speakers pairs in the doors and also to the subs.

Removal of the original Hi-Line system at the front, meant that the power was lost at the rear - on my Mk II at least. That lost supply needs to be restored - permanent 12v (purple/pink) and ignition switched 12v (AKA the remote) (purple/yellow). You can check these two at the HK amp itself and if they are not working, you will find the broken link between them, at the rear of your new DD. Just find a live 12v of each colour and link through to its opposite number.

My antenna is the single one, rather than the diversity so I have no experience of it at all. Basically the original radio receiver fed a signal back to the amp, telling it which antenna was best to use for the station it was tuned to. So the amp has only one output, but two inputs. I think someone suggested despite this, it works fine as the radio antnna feed to the DD. Assuming that last is correct, you will still need to find another way to feed the TMC. I can confirm that MarkUK's solution of a separate amp and (in my case) a long length of single core wire hidden in the roof lining gets the TMC working fine.

[EDIT] One extra point to maybe be aware of..

You will need to extend the radio antenna coax, from the original radio position in the wheel well, to the back of the DD at the from. That involves adapting the coax plug from the cars ISO coax plug to a DIN coax plug. The adaptor supplied with the unit has proven to be troublsome. Better to cut the ISO off and fit a male DIN sooner, rather than later.

[petergw60]

Hi Harry,

Thanks for that. Will investigate further, though will probably have to wait untill next weekend now!

Peter

[Mrmanbag]

I have managed to wire the amp as described in the previous posts, however, I appear to have a problem with phase! Does anyone know which wires correspond to which polarity from the hk amp unless anyone knows what I could have done to cause this when wiring the amp as described above?
I'm also confused about the Tmc antenna. I understand that people could use the Tmc on the original hi-line system but on seans unit you have to add an amp?
I understand that I have to extend the lead from the boot to the dd unit (as with the radio) but where do I take the lead from? Is there already a Tmc feed that one can use to extend to the dd unit? Will I have to use a signal amp?
Any help would be greatly appreciated, especially photos or visual aids!!!

[HarryM1BYT]

QUOTE=Mrmanbag

I have managed to wire the amp as described in the previous posts, however, I appear to have a problem with phase! Does anyone know which wires correspond to which polarity from the hk amp unless anyone knows what I could have done to cause this when wiring the amp as described above?

By phase, I assume you mean you have managed to cross the wire pairs over between DD and HK amp? Your best bet is to see if someone can reproduce for you a copy of the HK wiring codes or colours from RAVE.

I'm also confused about the Tmc antenna. I understand that people could use the Tmc on the original hi-line system but on seans unit you have to add an amp?

I think you may be confused on that point...
The Hi-line doesn't have TMC - some models have TM or Traffic Master. That is a very local system transmitted from the roadside, main roads only, giving holdups in the immediate area only. It shows the details in the little display in the dash.

TMC is the system transmitted via the national FM radio stations and carries details of all the problems in the UK. Your satnav then filters that to what might affect the route you have set.

I understand that I have to extend the lead from the boot to the dd unit (as with the radio) but where do I take the lead from? Is there already a Tmc feed that one can use to extend to the dd unit? Will I have to use a signal amp?

Two (or three) methods....

Some of us tried a Y splitter at the back of the DD, so that the one built in antenna could feed both radio and TMC. Several of us then suffered poor radio reception and changed to one of the methods below...

MarkUK tested several amps and found one which worked well. He installed that behind the DD, feeding just the TMC socket and deriving its 12v from the back of the DD. He then ran a DIN coax through to the original Rover amp, stripped the end of the coax and tapped onto the antenna in the rear window where it feeds into the amp. You will find the Mark's post explaining it on the forum.

I found there was still some degradation of reception on the radio, so used a variation, but still using his amp. I installed his amp close to the Rover amp at the rear and looped the 12v feed across from it to feed the new one. To act as an antenna I connected a length of single wire 6 to 8 feet long, pushed up around the roof lining. From the amp to the DD's TMC antenna socket I ran a 6m antenna extension cable.

Like this...

6/8 feet single wire <T amp> 6m coax <TMC antenna input at DD>

[Mrmanbag]

Many thanks Harry,
I really appreciate it, it's so hard to find the info you need when the posts get so long! I'm still trying to find the solution for the steering controls (wired). There seems to be so much conflicting info!
Perhaps a locked thread on the installation of seans dd with definitive info on the fitting of the unit?
Many thanks again, can I call upon you for the inevitable questions that will arise?

Stuart

[HarryM1BYT]

Originally Posted by Mrmanbag

Many thanks Harry,
I really appreciate it, it's so hard to find the info you need when the posts get so long! I'm still trying to find the solution for the steering controls (wired). There seems to be so much conflicting info!
Perhaps a locked thread on the installation of seans dd with definitive info on the fitting of the unit?
Many thanks again, can I call upon you for the inevitable questions that will arise?

Stuart

Yes, no problem. If I can help, I will.

[Mrmanbag]

Ok, getting there very slowly! I have got the Tmc amp from mark, but the radio reception is terrible. At the beginning of this thread there is some discussion with regards to the power to the existing aerial amp. Can anyone clarify where the feed comes from and which colour leads I should use to power the amp?

As always, my eternal thanks

Stuart

[HarryM1BYT]

Originally Posted by Mrmanbag

Ok, getting there very slowly! I have got the Tmc amp from mark, but the radio reception is terrible. At the beginning of this thread there is some discussion with regards to the power to the existing aerial amp. Can anyone clarify where the feed comes from and which colour leads I should use to power the amp?

As always, my eternal thanks

Stuart

Purple/yellow is the wire colour which is switched by the ignition, the one used to feed the original antenna amp and therefor also the one you need to use for your TMC amp. If you read my original submission above, you need to be aware that installing the DD as a replacement for an Hi-Line system, will disrupt that wire - which means your original antenna amp will lose its 12v supply. You need to link it across between the two looms as described.