450SLC Becker Mexico Cassette install part 2 – Upgrading the speakers

I am currently upgrading the radio in my 1977 Mercedes 450SLC.    It currently has a Pioneer MP3/CD Player I had installed not long after I purchased the car in 2003.   The Pioneer came out of my old 300E and was installed in early 2002.   As well as the Pioneer CD player, the car also had Pioneer speakers.   These pre-dated my ownership of the car.   Looking them up online, they appeared to be late 90s vintage, and were sold as drop in speakers for Chrysler models.   The installer must have replaced the Chrysler connectors with Becker.

In part 1, I covered procuring and testing the radio.   In this section I will cover the speakers.  Upgrading speakers on a Mercedes of this vintage is not easy.   The mounting points are really tight and the speakers sizes are very small.  The 107 is most similar to the W116.      The right hand drive W116 never got the dash upgrade that the rest of the cars did, so 107 speakers were pretty much identical throughout the production run.

The front of my car was unmodified – the Pioneer speakers fitting under the factory grilles.  In the rear, it appeared that the holes in the rear parcel shelf had been enlarged.   The factory grilles were long gone and pioneer speakers were using their own grilles.  I took measurements of the holes in the parcel shelf and the depth I had to work with.   Neither was much.     Since the rear factory grilles were gone, I needed to find a set of speakers that fitted into the allowable space and didn’t have horrible garish grilles.

There was also a third problem.  Many cheaper speakers do not publish detailed measurements of the speaker.   Firstly I had to rule out speakers that do not publish detailed dimensions, then find speakers that looked like they would fit, then find speakers with grilles I could live with.   It wasn’t an easy task.   I also wanted to use the same family of speaker front and back.

In the end I found a couple of pairs of focal speakers with simple grilles that looked like they would probably work.   They were from one of Focal’s more entry level families.   This was the RCX-100 for the fronts and the RCX-130 for the rears.

When the speakers arrived I started on the fronts.   The drivers side is by far the most difficult, so I started there.   There is far less clearance for the speaker magnet here.   Unfortunately my new Focal speaker almost fit, but the magnet fouled on some of the internal dash structure.  I’ve seen people use a Dremel to trim this back before, but I wasn’t really keen on doing that.   Before I made a final decision, I wanted to check the rears.

On the surface, the rears were a good fit.   The issue I had was that when I started testing the speakers, they must have been just touching something as they kept shorting out.   I was using the old Pioneer to do this testing as I didn’t want to damage the Becker amplifier.   My next test was to buy some spacer rings and see if I could make the speakers sit up a bit.   I couldn’t really make this work, as the sizes were not exactly what I was looking for.   I wanted this whole thing to be as unobtrusive as possible.     Based on this I gave up on these speakers and did some more research.  It was a shame as the grilles looked quite good.

On the W116 forum there was a thread about some speakers that fitted perfectly under the factory grilles.   These were the Visaton FX10 and FX13.   They didn’t come with grilles, which doesn’t matter for the fronts, but does for the rear.   Unlike most speakers, these are sold as individual units, not pairs. The photo below compares the Visaton with the Focals.   Since the Visaton speakers are supposed to fit under the factory grilles, I wondered if the rear parcel shelf had not been enlarged as much as I thought.   Based on that, I was able to obtain a set of factory grilles for the rear of the car from a club member.

When the Visaton speakers arrived, I started with the rears.   They are slightly smaller than the Focals so I was confident they would fit.   They did, and there was no problem with shorting out.   The issue was the grilles.   The parcel shelf had been enlarged a fair bit, so while the factory grilles covered the actual speaker, the mounting ears were far larger.  I’m not sure how I would have secured them even if I shaved off the ears and let the speakers just sit in place.   Doing a bit more research, it looks like people were cutting the ears of the speakers.    At least for now, I have re-used the pioneer grilles.   They just fitted, and looked fairly unobtrusive.   I’ll look for a better solution in the future.

On the fronts, they were a good fit.  I think they are about as large a speaker as you could mount without resorting to using a dremel on the car.   The passengers side was really easy.   Getting the factory grille back on again took a matter of minutes.   The drivers grille is much more of a pain, I still don’t have that one on again.

Based on all this, the new speakers sound better then the old Pioneers.  I suspect the larger Focals would have sounded better, but they didn’t fit without modification.   Now I have four working speakers I have tested, I can remove the old Pioneer for the final time.  The Visaton speakers are certainly a big upgrade to the old Pioneers.