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#5195 - 21/09/1999 10:30 Hunny
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
I have finally got my empeg installed into my Mini (yes, you read that correctly) as an interim while I get a proper installation schematic sorted out for our main car. The idea was to just get the thing working in any car, so I have shoved it into my daily transport in order to take advantage of the grin factor.

Let me tell you, on the grin scale, it's up around 9.99' out of 10

We have a '91 BRG Cooperised 1000cc; there's lots of wood in there now (Issigonis wouldn't have approved), but the chief benefit is the cockpit-wide wooden dashboard with a convenient radio aperture. This used to house a 4-channel Blaupunkt cassette radio which stopped functioning about a year ago; there's been an empty slot the for a while, so I finally thought "Why not?" and decided to testbed the empeg there first.

Out came the dash and radio to investigate the wiring; out came the Blaupunkt 60W two-way compact speakers. The wiring was pretty weedy, so I went straight out and invested in a lot of shielded phono cables, thick section 17 Amp power wire, insulated spade connectors, heat shrink insulator tubing and good quality thick multi-strand speaker cable.

I (conveniently) had an unused 20+20W Philips slimline car amp hanging around the house I bought years ago; since the output stages were designed for 4 ohm impedance and the Blaupunkts were 4 ohm and were quite reasonable quality, I decided to re-use them with improved cables. I was not looking for a top-notch installation, here; the reasoning behind this installation was that this is more of a test attempt to see how the empeg would sound, and give me a chance to use my new toy in action

To start with, I stripped the speakers to remove the (horrible) original cables, bored out a 1" reflex port into the side of each case in proximity to the bass dome. The cross over remained, and I wired up both speakers with the thick-section unshielded twin-cable. The speakers were mounted on the back parcel shelf; not an ideal location, but then you don't have much choice in a Mini. The cabling was fed down through the shelf, through the boot space and back into the passenger compartment with grommets on the holes.

The Philips amp is a 10-year old twin channel 20+20W/4 Ohm half-height DIN unit, with line in or speaker feed via dropper resistors. Since I had decided to use the front speaker outputs only and feed them to the amp (so I could leave the empeg set for neutral fade and balance to use both in car and home), I knew I would be working with line-out levels, so I dismantled the unit, removed the speaker input cables and droppers from the circuit board (hey, who's worried about guarantees? ;^) and then soldered gold-plated phonos onto the amp's line in lines to replace the horrible cheapy DIN connector that was already on there. The amp has a remote activate line, just right for what I had in mind; the amp fitted just beautifully under the back seat, slightly out of direct sunlight, and not immediately obvious from outside the car. Since it's off the floor, it doesn't get trodden on and has a nice bit of air circulation around the case vents. Additionally, I can turn round in the driver's seat at night and see this ghostly illuminated front panel peeking out from under the seat...

I cabled in the speakers and prepared cable extensions for power and remote on to bring the leads up to behind the dash from around the edge of the car, along the sills. The shielded phonos were connected to the amp inputs, and the whole lot taped down under the carpet edges with gaffa tape after checking the seats, or people stepping into the back, could not crush them. The phono cables were about half a meter too long, but being pre-fab, I didn't want to cut them to fit. Instead of bundling them up, the cables were laid and taped down in a large loop around the outside of the floor area to avoid induction interference problems. Phase one complete.

Phase two was to install the sled in the dash slot. After tidying up the existing cabling behind the dash, I looked at the aerial connector, and decided it was not so hot. The aerial came out, the clamp was cleaned up and the contact surface in the wing was cleaned and greased with vaseline before it was re-inserted and clamped down again. The cable was fed back through and a new connector put onto the co-ax.

At this point I started on the dash. I fixed the sled in place using the locator tabs cut into the sled plates. The metal is damn thick and difficult to bend easily without levering against the plates and warping them; I ended up positioning the sled and punching the tabs down with a mallet and centrepunch. The dashboard was also a bit thick for this (~1cm) which made the grip of the unit marginal. Additionally, the aperture in the dash was larger than the sled, leaving it flopping about. Upon a bit of investigation, it turned out that the empeg sled was not as tall as the previous sled, so I compared it with 3 others I had (conveniently to hand ;^), to find it was definitely the odd one out. I reported this in a previous post in this section (see "Sled dimensions"), and the final solution was to bind the sled casing with tape. While producing a better fit, it reduced the sled flange's ability to grip the dash. All in all, less than satisfactory. The dash went back in OK and I checked the insertion of the empeg. It didn't flap, and connected properly with the floating connector. However, the facia of the empeg is unfortunately not quite generous enough in cut, and doesn't really cover the edges of the sled properly - it's still distinctly visible with the unit inserted and is less than attractive. The solution would be to extend the height of the front panel upwards about 2mm, I feel.

The existing connections for the previous radio behind the dash were good enough and did not need to be disturbed, so I re-used them. The problem with this was that the earthing point was on the front bulkhead, which was the reason why I had to bring the amp's earth lead forward to this common earth point. Not ideal having a long earth lead, but that was why I bought fat section power cable (17A rated) to reduce ground bounce due to the return current from the amp. After cabling, I only measured milliohms between the amp and the earth point across 2m of earth cable - pretty reasonable.

The cable bundle from the back of the sled was conveniently accesible through the glove box aperture on the passenger's side, so I set about feeding the power cables and phonos from the amp up the side of the passenger firewall and through the dash shelf. I connected the positive iginition feed wire (switched) to a Y-connector and attached the amp feed and empeg choke to this; the choke capacity of 3A was insufficient to handle both amp and empeg without saturating and causing interference problems (or blowing it's built-in fuse in heated situations ;^) so I left the amp unsuppressed. The same was carried out with the earthing wire to the bulkhead; I also inserted the earth lead from the short phono adaptor cables included to reference the outputs to the amp earth. The amp phonos were connected to the front line-outs through these. All 6 phono connectors in the bundle were isolated by dint of heat shrink tubing. All other connectors were likewise insulated, and I checked the voltages at all power feeds with the ingnition on and the empeg and amp out of the loop. I was a tad surprised at my battery voltage (11V), which I later found out was due to little boys leaving the interior light switch on (phew!).

OK - Phase 3, the best bit. Ignition on, empeg in, and presto! On comes the winker LED, followed by the Tux boot screen. And there it hung, for about two minutes. It wouldn't boot - damn, what was wrong? I climbed into the car and turned the engine over and started it. The empeg instantly re-booted, kept booting, and -

BOOOOOOM BOOOOOM CRASH-A BOOOOOM CRASH etc.

- the amp switched on, and "Rock is Dead" at 0dB pumped out of the speakers.

I don't think I can recall another time where I have had such an incredible shock - the old cartoon images of the skin peeling off leaving just bones spring to mind.

Where's the bloody remote, wind the volume down to normal (!) levels. By now the neighbours had come out to look, and I'm sat there with the engine running, blood coming out of my ears, with a grin that the cheshire cat would have been envious of! Brilliant, brilliant, brilliant! Worked first time!

The clarity of playback is absolutely excellent; with the engine running, I have absolutely no electrical noise. On the road, there is no interference from indicators or the heated rear window element; in fact it is far better than any installation I've had done by garages. At rest with the engine off, there is no discernable hiss or extraneous noise at high or low volume when the music is playing. I think that careful cable choice, laying, connection and filtering have all resulted in a good installation. A little luck came in there somewhere, too.

Now the radio - well, I can succesfully tune in about 5 stations in the Netherlands, and one German one about 180 km away. This is not all the local stations I know are available hereabouts, but I am not upset. However, there are problems; the stereo stations break up, and as others have noted, signal strength is not tops on all of them. What I *have* noticed is that the two RDS stations I can tune into come in a 5 bars, and I have perfect reception. One is radio Haarlem (60km away near Amsterdam) and the other is Radio Rotterdam (85km). On the road, I seem to be able to tune and receive RDS based stations much better than non-RDS. The tuning is a bit hit and miss, and I cannot store stations as presets; the UP and DOWN tuning is also a bit dickey, as the UP key only seems to tune up to 97 MHz, then stops, whereas the DOWN key tunes down, loops round to the top end of the frequency scale and keeps going down with each further seek. Odd. The RDS data display - weeeellll, as the curate said, "Good in parts". When tuned to Radio Haarlem, I first see RH's station banner OK. The banner then seems to cycle through about 8 different banners *from different stations*, including Radio Rotterdam, and this is occasionaly interleaved with track info. It also breaks up and produces corrupted text characters randommly, in spite of the fact that the audio signal (on R Haarlem) is strong at 5 bars and has a good stereo image with no interference. Possible bug?

So, after all this, what's the title got to do with it? Well, it's like this -

many years ago, E.E. Milne created a character in the Pooh stories who bounced onto the scene with great verve and declared he was "Tigger" (T-I-Double Guh- Uh). When Pooh offered him hunny to eat, he pounced and drank with great gusto. After a second, however, he stopped and stated:

"Tiggers *don't* like Hunny!"

After getting Emma empeg going in the Mini, I decided to travel in a convoy with my friends; we use 27 MHz CB radios to stay in touch in the convoy. We have completely portable setups whereby we just clamp the antennae to the roof with foot magnets, cable into the car, plug in mini speakers to the CBs and stick the power cable in the lighter sockets. Away you go - instant fun.

The trouble started when I was 200 m down the road and had just put some suitable road music on at high volume (which had of course resulted in the customary frozen wide grin). Down go the windows, up goes the bass ("Bloody hooligans!!!"), I thumb the transmit key for the first bleat of the day and -

RAAAAAAAAAAAAAAAAAAAAAAZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ

- at about 15 dB down amplification.

"empegs *don't* like CBs!"



PS I'm going to be looking into this and I'll give you a report if I can find out what's happening, so keep a lookout for a follow-up story.

PPS I'll be putting up some images of the car and the installation sometime soon when I get the pictures processed and scanned

Keep empegging!

_________________________
One of the few remaining Mk1 owners... #00015

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#5196 - 21/09/1999 11:38 Re: Hunny [Re: schofiel]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Hmm. CBs *do* tend to interfere with stuff - it doesn't take a lot to induce audible noise on amp feeds. Not sure what to suggest - cambscar might have an idea.

Hugo
(reminds me of a friend keying up his 25w SSB transceiver in a garage forecourt - very illegal and dangerous, btw as it's a suitably dangerous amount of power in terms of sparks - and it broke into the garage PA amplifier, so everyone within a couple of hundred meters could hear him through their speaker system).


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#5197 - 21/09/1999 13:27 Re: Hunny [Re: altman]
Nils
member

Registered: 09/06/1999
Posts: 197
Loc: Germany
schoffel, this must have been the goddamn most detailed description of a car audio install in the history, and amazingly enough it was still laughing-ass-away funny :)

Thanks for that damn you §$%§$%§$% bastard for beeing lucky enough to have no noise in your install ;)

Nils


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#5198 - 22/09/1999 05:41 Re: Hunny [Re: Nils]
ShadowMan
addict

Registered: 09/06/1999
Posts: 558
Loc: Newfoundland, Canada
"beeing" lol, good pun, even if accidental ;)

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12 gig empeg Mark II, SN: 080000101
30 gig RioCar SN: 30103114
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#5199 - 22/09/1999 05:50 Re: Hunny [Re: ShadowMan]
Nils
member

Registered: 09/06/1999
Posts: 197
Loc: Germany
Hahe ;)
Yes it was accidential, but now, as you mention it, its pretty funny :)

Nils


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#5200 - 22/09/1999 11:49 Re: Hunny [Re: altman]
Cambscar
journeyman

Registered: 21/07/1999
Posts: 61
Loc: Cambridge, UK
S'been a good while since I've messed around with CB. I think the first thing I'd consider is whether you need to regularly change channels. If not, then you could mount the base unit in the boot and use a mic and speaker extension - if the unit's more than a couple of years old, it probably chucks out a huge amount of RFI, and the boot enclosure should screen a good bit of it. Moving the power feed so it's fed directly from the battery's probably a good idea too, and an inductor/cap filter on the power line's definitely worth adding as well. AIUI, you're running the Empeg amp from an existing supply in the car?? If so, moving that so it's fed directly from the battery as well might help. If it's got a remote switch on lead, then the amp shouldn't really need to be ignition fed, and even if it does, you can always relay it's power feed using the orange wire off the Empeg. All that, and ensuring that you've got the CB aerial mounted about as far back as possible to keep the distance between it and the Empeg/radio aerial's about as much as I can come up with....

Dominic


Cambridge Car Audio
http://www.cambscaraudio.co.uk

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#5201 - 28/09/1999 02:11 Re: Hunny [Re: schofiel]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Following up on the CB interference I mentioned in my previous post, I had a look over the weekend at what was causing the problem.

With the engine off, I was able to transmit without any problems on the empeg. As soon as the engine's running, it causes interference during transmit.

Rather than be totally scientific, I swapped my CB for another one and tried that.

Guess what? No interference. Swap the old one back in, BUZZZZZZ!

So it looks like there's something wrong with the CB that is causing this. The unit itself has had trouble with squelch control and occasional transmit problems, so I suspect it's on the way out - probably voltage regulation problems?

One point of note; the power tap-off point for the CB and the empeg is the same, so there's obviously some influence there.

Pictures to come.



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One of the few remaining Mk1 owners... #00015

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#5202 - 28/09/1999 03:09 Re: Hunny [Re: schofiel]
Mark Petersen
journeyman

Registered: 19/09/1999
Posts: 97
Loc: Denmark, Kbh Ø
You migth consider noice from the empge it is a computer, and those are known to interefie with radio reseption,
every time my GSM mobilphone rings my sound system gows BuZZ BuZZ BuZZ in an constant reyhem.

Mark
emaks rouls #10677
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Mark wait for mk III with a USB Host/slave (USB->GPS)(USB->Bluetooth)(USB->You name it)

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#5203 - 28/09/1999 03:18 Re: Hunny [Re: Mark Petersen]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
I agree, but don't forget that the *CB* was interfering with the *empeg*, not the other way around. I pretty sure the CB itself is damaged.

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One of the few remaining Mk1 owners... #00015

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