Monitor Audio S6 tweek

Hi I'm looking for some advice and guidence....

I have some Monitor Audio Silver 6 speakers and now find them a little bright. Is this something that could be improved in the crossover of the speaker?

I've attached the diagram, if anyone could help that would be great.

Also any other tweeks that could be recommended

Many thanks
Rob
 

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Values

Crossover should make some more sence with the values.

L1 = 4mH inductor 0.7mm wire 10x10x50mm laminated steel core
L2 = 1.0mh inductor 0.7mm wire 40x8x8mm laminated steel core
L3 = 0.2mH inductor 0.4-0.5mm wire Air core bobbin
C1 = 4.0uf Polyester Cap 100v
C2 = 4.7uF (XP) Polypropylene Cap
R1 = 2R7 7W wire wound resistor

Here is the link to the spec http://www.monitoraudio.co.uk/produ...oduct=44&area=2
 
Hi Rob.
Sorry i'm late, at least 3 years, but i'm starting to feel some stress with my MA S6!
Now i complain about some mid and treble stress, and lack of ambience retrieval!
Could be the system? A Sony SCD-XA3000-ES with a LME49722 in the differential stage and a OPA2134 in the lowpass stage, plus some Elna Silmic II to beef up the allready heavy power supply!
The amp is an Advance Acoustic MAP-407, with a LM4562 at the first preamp stage and the original OPA2134 in the second stage, with beefed up preamp power supply!
The last amp before de MAP-407 was a NAD C370 and it plays a lot worst with the S6 than the MAP-407!
So what do i have here? Psych mood, bad mains supply, or a bad system?
I look into the crossover schematic and the only thing i could blame instantly is the wire! The rest seems pretty decent to me!
The internal wire is OFC or Alluminium?
Any ideas? The tonal balance is a bit foward and lack acoustical information, although is very warm and confortable with decent sound stage!

Best regards

Paulo
:confused:
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
I don't think this will put much stress on the amp. It may have an effect on how it lowers the treble. If you put the resistor in parallel, it will lower the Q of the filter so more lower treble may be attenuated. If you increase the series resitance, more upper treble may be attenuated because the impedance of the existing crossover is higher at the lower treble.

You want to decide whether your system is bright due to the top end being loud, or is it because the lower treble has too much off axis energy.
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
Good googling, jerome.

After seeing that, noticing the two response peaks and the impedance peak... I'd begin with robs parallel resistor and then increase the series resistor until it sounded better. I'd ignore everything above 10k in this case but I'd also wonder about the woofer's top end.
 
;)
Hi Everybody!Thanks for the support!

Dear Mr. Allen, you're right. If the S6 are similiar to the RS6, then the 22 Ohms resistor in parallel with the tweeter will drop the impedance around 0,7Ohms at 3Khz. Not a stress situation indeed!

Dear Mr. Jerome, you show some insight around the MA S6 X_over.
Did you listen some S6 with the mod you propose, or its an academic exercise, which contains a possible solution?
The Bass unit roll off is not enough, or the 10uF cap helps the integration of the bass unit with midrange unit?
Its well worth to try, only the 10uF in MKP caps are extra expensive. Maybe bipolar cans can do a decent job!Only the tweeter 10uF is crucial, and must be MKP type!

Thanks again for your attention!

I hope i can try it quickly!

Best regards

Paulo
:cheers:
 

jerome69

Member
2008-02-18 11:33 am
Lyon
;)
Hi Everybody!Thanks for the support!

Dear Mr. Allen, you're right. If the S6 are similiar to the RS6, then the 22 Ohms resistor in parallel with the tweeter will drop the impedance around 0,7Ohms at 3Khz. Not a stress situation indeed!

Dear Mr. Jerome, you show some insight around the MA S6 X_over.
Did you listen some S6 with the mod you propose, or its an academic exercise, which contains a possible solution?
The Bass unit roll off is not enough, or the 10uF cap helps the integration of the bass unit with midrange unit?
Its well worth to try, only the 10uF in MKP caps are extra expensive. Maybe bipolar cans can do a decent job!Only the tweeter 10uF is crucial, and must be MKP type!
Hi,

It is not academic. I never heard a S6. But I have done enough tweaks to other loudspeakers to recognize the same topology of crossover and curiously the value are the same. These tweaks was done with actual measurements.
Tweak Eltax concept 400
Tweak JBL TLX215

The impedance compensation on the woofer helps to do a better roll off in the treble. Less bad treble in this area.

The treble should be more clear.
Let us know how it sounds ;)

Cheers.
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
Paluse, you can test with a cheap bi-polar to see if it makes the difference that you want. Mind that this tweak will cause phase differences that may produce a hole in the response, but it's worth a try to get the sound you want.

If you were to instead start with Robs parallel resistor and then add more and more series resistance, this will give a more predictable result.
 

AllenB

Moderator
Paid Member
2008-10-18 11:31 am
Jerome, your idea is worth a try. Of course how can any one of us be certain about our ideas from where we sit? (except Rob, of course who owns a pair). We are making educated guesses, but I'd dare to give Monitor Audio just a pinch of credit (or benefit of the doubt) vis-a-vis the phase, at least within a margin.

Sometimes tweeters will sound better when you take the pressure off the resonance, especially at higher power levels, but this is not really the effect that Paluse is chasing. Maybe I am not understanding your point when I assume it may only confuse matters to add the capacitor.
 
Quite likely you'll be disappointed with the result. You're not describing what you find wrong very clearly, but I'd suspect it's harshness from metal drivers.

For the very top end, I'd suggest you try a Zobel network across the metal tweeter. This is typically 6.8 ohm 10W wirewound and a polypropylene 0.82uF or 1uF series network. It does more than you might expect because it makes a much nicer load for the amplifier without affecting impedance much.

Taming the metal woofer is trickier. You might try the same value Zobel across the 1mH bass inductor making what is called a tank. It's not a circuit I like much because it does some odd things reducing impedance to about 5 ohms at the high end, but it will sound radically different due to the 5kHz notch on the metal cone breakup region.
 
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