Speakers & crossover frequencies on my 126 - PeachParts Mercedes-Benz Forum

goldstone · #1 02-12-2003, 03:35 PM

Just upgraded my headunit and added a CD changer to the mix. (I opted to bypass the fader and the stock amps.) This has made an enormous improvement to the audio in my 126. Inspired, I'm now contemplating the speaker system...

A few questions for those in the "been there/done that" category:

1) What are the crossover frequencies selected by Mercedes for the stock speaker system in my '89 420SEL?

2) Do I need to be concerned with these crossovers if I want to simply upgrade the dash speakers (to 4x6 Eclipse Euros as per Scott, or to MB Quarts as per others)?

3) Will simply upgrading the in-dash speakers (or any of the speakers for that matter) WITHOUT rewiring/replacing the entire system make an appreciable difference (i.e. obvious to the average--non-audiophile--listener?)

Bottom Line: I'll do it in a flash if it will significantly improve the audio, but it's certainly not worth the effort if you tell me the difference will only be marginal over what I've already achieved.

Thanks!

goldstone · #2 02-15-2003, 09:53 PM

Are these tough questions? (I didn't think so initially, but the silence is deafening!)

Any help before I spend additional amounts on my audio system would be GREATLY appreciated.

zla39fj · #3 02-16-2003, 05:41 PM

I'll bite.
As far as crossover frequencies provided by Mercedes I have no idea. Since you have replaced the head unit and bypassed the fader and amps the only possible crossover that would effect your system would be passive crossovers between the head unit and supplied speakers. To ensure no surprises when you install aftermarket speakers it is better to simply not use the factory wiring. Running new speaker wires is easy and will facilitate returning the car to stock condition if you sell the car later. The most difficult aspect of rewiring your speakers will be the rear speakers. I have found that using a straightened out coat hanger to pull the new wires under the carpet has sped up the process by not having to actually lift up the carpet. As far as what type of speakers to use it is a personal prefernce that you will have to decide for yourself but let me recommend INFINITY. I hope this helps.

goldstone · #4 02-16-2003, 11:23 PM

Many thanks for the input.

1) As far as wiring, it's already done: I ran four sets of new wires from the head unit back to the stock amps and simply tapped into the existing speakers from that location (bypassing the amps themselves, as noted above.)

2) As far as crossovers are concerned (passive or otherwise), I think I must be a little confused (not unusual!) I thought some sort of crossover was necessary in a multi-way speaker system to isolate the desired frequencies to be sent to each component. (Otherwise, wouldn't woofers, mids, as well as tweeters just receive--and attempt to retransmit--ALL parts of the sound spectrum with varying degrees of efficiency

)

I suspect my reasoning is faulty here, since the electrical schematics of the 420SEL's speaker system show no inline capacitors or inductors, but would enjoy being set straight by any of you willing and able to do so.

3) Finally, is there no objective measure to determine which speakers best replicate originally recorded material? For instance, let's say one were to set up sound measuring equipment at a recording site of say, a piano concert. Now, by means of various speaker layouts, crossovers, equalization, etc. in a given car's interior, couldn't one theoretically find the combination that best replicated the objective sound measurements taken at the original performance?

After all, it seems to me that injecting individuals' ears into the mix just adds subjectivity. You may like Infinities, the next guy MB Quarts, ad infinitum. But shouldn't the objective be to reproduce what the original performance/mix ACTUALLY sounded like? If the listener wants to tweak the original content to fit their personal tastes, then do so; but shouldn't the optimal speaker system's primary function be--by definition--to faithfully reproduce the original material?

Sorry for rambling on, but this inquiring mind REALLY wants to know!!!

zla39fj · #5 02-17-2003, 01:54 AM

goldstone
crossovers are used to direct specific frequencies to appropriate drivers. Please note that a coaxial speaker will have a crossover(passive) built right into the signal chain. This allows a multi driver speaker(tweet/mid/sub) to play a broad band of frequencies. Even so a 4x6 coaxial speaker will not be able to accurately reproduce sound at an audiophile level below midbass. This is the main reason true fanatics of sound reproduction will employ several single driver speaker set ups utilizing active and passive crossovers, equalizers, amplifiers, sound deadening, sound processors and laser alignments. All of this in an effort to "hear what the artist heard". If one has the time, desire and talent to achieve this goal then all is well. As far as particular parameters utilized to identify superior speakers, forget it. It is more important to use your ears instead of a salespersons mouth. The asolute best car audio system I ever heard was in a 90 Honda Civic LX and he only used a set of 5.25" components(Oz Audio) in custom made kickpanels up front, a single 12" sub (Oz Audio) in the trunk, and a 2 channel Sherwood amp. He installed it all himself and he said it took him 4 months of nights and weekends. One ofthe worst systems I heard was in an old Lincoln with over 12 speakers, maybe 4 amps and a trunk full of subs. All top named products with big price tags. Money is not the issue. Talent, time and desire can deliver a superior SQ system.

goldstone · #6 02-17-2003, 11:14 AM

The great thing about this forum is the threads of knowledge that are available; but it's basic summaries like yours that help weave those threads into a logical--and usable--form for us novices. Your last informative post tied up quite a few loose ends in my understanding of how various audio components function together.
Quote:

If one has the time, desire and talent...

Thanks for sharing yours!!!

zla39fj · #7 02-17-2003, 02:57 PM

goldstone
Do you plan to do the install yourself or are you going to find a "good shop"?

goldstone · #8 02-17-2003, 03:15 PM

Purely for the satisfaction of doing so, I prefer to install it myself. On the other hand, if you tell me there's much more to the upgrade than meets the eye, then I'd willingly pay a pro.

(After all is said and done, I'm still not sure I know how much of an improvement to actually expect from a speaker retrofit. Is it more effort than it's worth?)

zla39fj · #9 02-17-2003, 03:32 PM

goldstone
Simply upgrading your speakers from the factory originals can improve your sound quality especially if you use a high powered low distortion amplifier. Be advised that some brands are better than others due to power handling, frequency response etc. but I have never heard a good Audiovox or Roadmaster system. Infinity, MB Quart, Rockford Fosgate, Rainbow and Pioneer, Alpine and of course Oz Audio make great gear that in a 'plug and play mode'is a vast improvement over factory stuff. But regardless of who makes it a talented installer can make it sound good. Try it yourself first then you will know if you want outside help. The installer of the 90 Honda also did a 87 VW GTI with a complete Radio Shack Optimus system that left me in awe. It is not the price of the components it is the skill of the installer. Good luck and happy hunting.

goldstone · #10 02-18-2003, 05:19 PM

They say, "The more you learn, the more you realize you don't know..."

Case in Point:
After digesting the previous posts, I started wondering about the role amplifiers play here.

As I've already mentioned, I chose to bypass the fader AND the two stock amplifiers located behind the 126 backseat, relying instead on my new head unit's internal fader and 4x25 amp to drive the stock speakers directly. This sounds MUCH better than before.

What's giving me pause at this point is whether the improvement is wholly attributable to the superior 4-channel configuration and NOT to the changed amp setup. After all, at 4x25W MAX OUTPUT, the head unit's internal amp is probably only putting out around half of that power on average (RMS). And 12.5 watts isn't much oomph to be driving a ten-speaker system.

So the Question is this:
Would I have done better, powerwise, to have instead used the head unit's 4 pre-outs and tapped the stock amplifiers to drive the speaks? And, given that most/all of the speakers discussed as good replacements indicate AT LEAST 30W RMS for proper efficiency, how can my little head unit hope to drive any of them efficiently without additional help from an external amp???

zla39fj · #11 02-19-2003, 12:28 AM

goldstone
If you noticed an improvement in sound quality after bypassing the stock amps and fader you may have either eliminated faulty components or illustrated the superiority of aftermarket equipment. Removing the original equipment completely from the car is a personal matter but cutting of factory wiring should be avoided. The 10 speaker set up is a mystery to me. I can not see why so many drivers are needed in an automobile. Maybe it was a marketing decision that catered to the more is 'best school of thought which is probably true in most cases but not in terms of car stereo. The exact number of watts in your system is not as important as the quality of the sound you hear. I have not run across a speaker that needed 30watts/rms to be heard. I have heard drastic improvements when changing stock speakers due to their ohm ratings and shabby construction. Should you decide to take the time to tap into your stock amps and use your new head unit to drive all 10 speakers in your car please advise me on what the out come is. Be careful though.