SF G Homage mods

MiL

Member
2010-06-01 12:36 am
Hello,

Just got my hands on a lovely pair of SF Guarneri Homage. They are really good, so good they'll replace my much more modern and very costly Raidho speakers. The Homage may not have the same resolving power or deep bass but they still resolve just right and bass is tighter though half octave less or so. Otherwise the beat the Raidho with great margin.

I am thinking if some mods could be done BUT they should be of the art so they could be reverted to original.
As I run only single wire, can one terminal pair be made to single wire config. I guess it is about taking the backing plate off and as I hope just move cables, or?
Could it be beneficial in changing for a pair of better quality terminals from Furutech or WBT?
Or are they better served by bi-wiring?
My pair is from 2001 and I wonder what capacitors are used in the x-over, are there any that could have deteriorated during 15 years?

Anyone tried to re-wire the system?
Anyone that replaced X-overs with a x-over with new components but same spec?
Any other mods, like I saw on a Japanese page there they replaced the cover frame for bass/mid with a frame made from maple?.
Anyone know where replacement tweeter and bass/mid units could be bought or is it strictly 2nd hand?

Best/Mike
 
It seems to be a 6" polycone bass and metal tweeter. A fairly classic combination:
Vifa 2-Way Loudspeaker System

I think you need to delve into the crossover to see what might be done. I doubt it's a bad design.
 

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MiL

Member
2010-06-01 12:36 am
Hi and thanks for your replies,

Well digging into the x-over for function/spec testing each component is the only way to go of course. The x-over is in no doubt an excellent construction my concern was about components that could be affected by time (15 years) like caps.

Of course I like the speaker and I run as I see it a very good amp, Aavik U-300, which is extreme dynamic low noise specially its riaa is the quietest and best I ever heard hence I bought it. The amp side is no problem but the amp may show some shortcomings or deteriorated components in the x-over.

I am not after more bass just that there are 'spots' in the freq spectrum that seem to be slight distorted, hence my question if it could be addressed with small adjustments like single wire application or replacing so-so caps.

The Homage is more dynamic than the highly regarded Raidhos, not bad for a 23 year old design.

Well I'll start with making them single wired.

/Mike
 
Without drawing up the crossover diagram, and maybe renewing tired NP electrolytics if any are fitted, you're getting nowhere. :)

Simpilstic shallow filters appeal to some people, but tend to distort at high level. That's how it works.

This is diy, and your ears judge when to stop in the end. 6" polycone bass and metal tweeter is established territory. Most of the issues are due to an unpleasant 5kHz cone resonance that all 6" basses have. This can be fixed with a 6kHz notch after the bass coil. Tweeters usually sound better on steeper filters with some attenuation.

I have seen damping materials put on the front baffle often enough. It's cheap entertainment. I don't know what it does really. :D
 

Jay

Banned
2003-02-11 9:02 am
Jakarta
Will try it! Perhaps the 3-legged tweeter protection 'disturbs' as well as I saw some Japanese mods to Homage where they omitted the 3-legged protection.

You have stated that you want to be able to limit the mod such that you will be able to revert back the mod? This may be difficult, especially if you think about removing the tweeter protection...

This speaker is special, so you should know the "importance" of possible upgrades...

Any other mods, like I saw on a Japanese page there they replaced the cover frame for bass/mid with a frame made from maple?.

The grills/covers is intended to "cover" the drivers and to provide "cosmetics". It is definitely in the way of good sound. So you can remove them while listening or find a better substitute.

Could it be beneficial in changing for a pair of better quality terminals from Furutech or WBT?

Given the quality of the speaker, it will be hardly audible. You can listen to the speaker "without" terminal, which is the best condition, and decide if upgrading the terminal worth it. I believe not.

Or are they better served by bi-wiring?

Yes, bi-wiring will solve your "problem" with transparency, not the other way around (single wire).

My pair is from 2001 and I wonder what capacitors are used in the x-over, are there any that could have deteriorated during 15 years?

If the sound is okay, then nothing to worry about (we'll see later what is it that you find as problem to the sound). Yes, caps can change capacitance, as I have experienced several times with my DIY crossovers, but I have never seen commercial ones to have this problem. I don't believe SF uses unproven "brand".

Anyone tried to re-wire the system?

Wire could have "color". It's like tone control, so I myself will not consider such upgrade. But nothing can stop you from trying brands which are known to sound bright or transparent, most probably silver wire.

But if you think that the original cable could be deteriorated, I don't think so. Such speaker must have used good OFC cable. But you can check the color of it (blacken due to oxidation) or measure it's resistance (bad if higher than any other cable).

Anyone that replaced X-overs with a x-over with new components but same spec?

Yes, even tho speaker is expensive, manufacturer will always cut cost in crossover components. But the capacitor that will improve the sound considerably is the one that cost a fortune. It is perfectly okay if you like the speaker and trying to get every bit of possible improvement (especially if you are a DIYer who can re-use the components).

But remember to measure the components. Tolerance is too high and you cannot rely on the printed spec.

I am not after more bass just that there are 'spots' in the freq spectrum that seem to be slight distorted, hence my question if it could be addressed with small adjustments like single wire application or replacing so-so caps.

The port might have resonance. You can strengthen the tube (may be with resin) but this will modify the speaker (but no one will notice anyway).

I have never trusted class-D amps. They are the most dynamics, yes, but isn't enjoyment the first priority? I checked your amp and even the spec shows quite high IM distortion. IMD is usually held responsible with "fatigue". Class-A amps usually have the opposite trait regarding fatigue.

There are many expensive audiophile class-A amps out there, which I believe you might have auditioned. From DIY stuff I have only built the Moskido (60W) that might fit your speaker.

Regarding to your speaker design choice, there is more in a class-A amp beside the enjoyment thingy.
 
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MiL

Member
2010-06-01 12:36 am
Hi Jay et al,

Many thanks for your kind input and in particular the exhaustive response by Jay.

Gave me a lot food for thought.

Jay, lend an ear to the Aavik and you may change your mind and for sure it has the most quiet and musical riia I had the pleasure to listen to amongst high profile ones.

Agree that class A may give that nth factor but at present I left that camp for a 'simple' set up.

Cheers/Mike
 
Mike, it is a scarcely admitted fact in Audio that ALL loudspeakers are compromised. But true.

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IDK what the crossover is, but you need to work it out. It might be like this.

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What happens with a little 6" bass at high volume is it goes into breakup and non-linearity due to excessive movement and bass outside the magnet gap. It can get ugly:

473402d1427138438-seas-trim-w22ex001-wg-rocking-mode.jpg


Generally, steeper filters have less distortion, being kinder on excursion. Other factors include a flat impedance, which is easier for amplifiers, which if you think about it, have to perform minute feedback calculations to maintain flat output. So, TBH, I think you need to get a grip on the real issues and work out the schematic.

Taking out the protection polyfuse will brighten up the tweeter response about 2dB, because they have a natural resistance of about 2 ohms. And you will hear it. But that may be Fools' Gold. The fact is that small speakers don't go loud without distortion.
 
There's nothing to dislike at all about that speaker. If the wires and connectors and soldering are in good shape, it should work as advertised.

539013d1458613393-sf-g-homage-mods-sf-guarneri-homage.jpg


I don't know what they are under the cosmetics, but it's possible they are SEAS or Scanspeak or Peerless chassis.
DIY-Loudspeakers

The crossover looks impossible to disassemble. But obviously competent and second order, or higher. Capacitors are plastic film, so shouldn't deteriorate.

So not much to do with that one! Polish it? :D
 

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I suppose we could have questioned whether these are ferrofluid tweeters... Sonus Faber Guarneri Homage. Ferrofluid dries out after 15 years and turns into solid brown gunge in the voicecoil gap. Bit of a a pain. Stops the tweeter working.

539013d1458613393-sf-g-homage-mods-sf-guarneri-homage.jpg


Description: Limited-edition, two-way loudspeaker with matching stand. Drive-units: 1.1" (28mm) silk-dome tweeter, 6.5" (165mm and 8 ohm) polypropylene-cone woofer. Manufacturer's specifications: None. Measured specifications: crossover frequency: 2.5kHz. Electrical crossover slopes: 1st-order, 6dB/octave. Frequency response: 55Hz-20kHz, ±3dB. Sensitivity: 86.5dB/W/m (2.83V). Nominal impedance: 6 ohms. Power handling: 100W peak program.
Read more at Sonus Faber Guarneri Homage loudspeaker Specifications | Stereophile.com

Does look like a Peerless woofer, with the inverted dustcap.