Solen Electronique and S3100 MKII x'over build

[Bernard Wolf]

I am toying with the idea of changing the diaphragms of the 2426H drivers in my S3100 to a Aquaplas one from a 275nd. I only have 1 275 but 2 dias..

So.. I contacted Solen here in Montreal about building a MKII network. I sent them the schematic. Here is their response:

Dear Sir,

We can do this X-over for you, however there are a few issues;


1-The original X-over uses poor quality Electrolytic Capacitors, which is why there is a +9v loading circuit, that ads a lot of un-necessary parts.
2-The original X-over has a switch to play with the tweeter efficiency.


The first option is not needed if we use good quality capacitors.


The second option can be replaced with a variable L-pad.


For your X-over box request, we can do painted wooden box with a smoke plexiglass top.


Let me know if you wish to go this way?


Regards,

Chris

I answered back:

Hello Chris,
From what I gather it is the 9 volt battery which is the 'special' feature of this x'over. It is used in their $50,000.00 Everest for example. I would not want to change that out. What say you?

His reply:

Dear Sir,

The +9v feature is there to pre-load the electrolytic capacitors, to increase there response speed. It is un-necessary to use such a contraption for good capacitors.


Regards,
Chris

My reply:

Dear Chris,

So, not being smart.. you know better than Greg Timbers the head designer of JBL who has designed all of their high end speakers? I will take your thoughts into consideration, but really.. do you not think JBL would just have done the same if what you say is true? Or, do you really think they do not know what they are doing?

Bernard

PS: for what it is worth, what kind of estimated cost would be involved in doing it your way?



Very interesting, no?

[grumpy]

Well, now you have at least two opinions/schools-of-thought

There is merit in both. Certainly, there is also merit in putting dollars where they are
of value in a commercial product.

My own take on this: Biasing very large value electrolytic capacitors (typically less
expensive when electrolytic) in low frequency audio circuits appears to have an
audible effect that is worth the effort. Biasing small value capacitors may also
have a an audible effect... that may indeed be less audible when using certain
capacitors (often more expensive).

I'm sure both gentlemen have extensive listening experience (and diverse
targets) that led to their conclusions, both of which, are ultimately intended
to present "better" sound to the listener.

Personally, if the cost to assemble a bias-able crossover was not insanely
more expensive, and within a budget I could justify, I would lean in that
direction... just to satisfy my own curiosity.

[Mannermusic]

Well, now you have at least two opinions/schools-of-thought

There is merit in both. Certainly, there is also merit in putting dollars where they are
of value in a commercial product.

My own take on this: Biasing very large value electrolytic capacitors (typically less
expensive when electrolytic) in low frequency audio circuits appears to have an
audible effect that is worth the effort. Biasing small value capacitors may also
have a an audible effect... that may indeed be less audible when using certain
capacitors (often more expensive).

I'm sure both gentlemen have extensive listening experience (and diverse
targets) that led to their conclusions, both of which, are ultimately intended
to present "better" sound to the listener.

Personally, if the cost to assemble a bias-able crossover was not insanely
more expensive, and within a budget I could justify, I would lean in that
direction... just to satisfy my own curiosity.

Great post. Just to add: I'm using a 3155 filter without the bias complexity. Use Solen caps with selective by-pass caps. It sounds pretty good . . . to the extent I've never had the burning desire to add the biasing complexity. After listening to this engineer from Solen, I doubt I ever will. I'm more interested in the music, for one thing.

[Bernard Wolf]

here is the latest from Solen.. we will see what the price might be soon.





Dear Sir,

He probably know's a good deal about X-over design too, however I have seen very expensive Loudspeakers (200,000$) out there using poor quality X-over parts. The reason why they cut corners like this is unknown to me.


However you should know we have been designing and developing passive X-overs for the past 32 years, so we know a few things about X-over design.


Before we go on with a quotation, I would just like to know what type of finish would you like on your X-over boxes, painted or stained veneer?


Regards,
Chris

[Bernard Wolf]

So here is the quote without boxes just the x'over mounted on a PCB:

$430.00 CAD the pair.

Not too bad. Now all I have to consider is if this will work out for my application of just changing the dias in my 2426h to an aquaplased 275nd diaphram. Wish I knew the answer to that one. Any thoughts appreciated.

Bernard

[grumpy]

Having swapped 2426H diaphragms out for aquaplassed units in a 4430 pair a few years ago,
I don't recall much of a measured level difference.

I'll try to check if I kept 2426 pre-post aquaplas measurements.

The MkII circuit assumes 275nd drivers ... so if you have MkII crossovers built,
are you asking if substituting 2426 drivers (with aquaplassed diaphragms) in place
of an actual 275nd driver is a reasonable equivalent?

[Bernard Wolf]

That is the plan.. I have one complete 275nd but have been unable to get another for about 8 yrs now.. got one ??

[Bernard Wolf]

If you do a 275nd search you will find quite a bit of info where Zilch and Mr. Widget, Earl K and others hashed this over:

http://www.audioheritage.org/vbullet...ighlight=275nd

I'm not sure we ever really came to any great conclusions.. esp me. I still am not too certain as to what I hope to accomplish here. I may in the end just have Solen build me a new/better NS3100 x'over for the 2426H.

We will see.

[Ian Mackenzie]

I have compare the dusted and un dusted.

The upper mid range has less glare, but the highs are less responsive.

The charge coupling brings back the edge and bit.

[Bernard Wolf]

I have compare the dusted and un dusted.

The upper mid range has less glare, but the highs are less responsive.

The charge coupling brings back the edge and bit.

Thanks for that bit of info Ian. Much appreciated. The last thing that I would want is truncated highs.. maybe they would work best in a 3 way design? I am too old to do much experimentation at this point. I am leaning towards just having an upgraded x'over done for me. The bee in my bonnet all this time is having that 1 275nd and the extra dias.

[grumpy]

I think I have more of a grip on the issues... I'd forgotten about the thread from years back.
(essentially I'm just summarizing below, conversations from 8-9 years ago)

1) will a 2426 body + 275nd diaphragm have the same level and response as a stock 275nd?

my -guess-: minor difference in amplitude overall (1-2dB looking at Zilch's simulated crossover
plots comparing the LF drive levels), and a HF response that may not roll off as quickly
(see #3 below).

2) would the resonances that are being specifically compensated for in the MkII crossover the
same level and frequency be the same with the 2426/275 combo, and are they primarily due to the horn?

my -guess-: maybe and probably... I would think the peaks being compensated with the parametric-like
sections (notch filters) could be pushed around a small bit, but if major driver resonances of the horn/
driver combo are off, a larger section of the desired response in the crossover area could be off target.

3) what effect on response did plating the pole piece in copper have other then "high frequency extension"

just have general words from the brochures, no response plot or spec for this.

It would really be helpful to have a local buddy run FR plots with both 275nd and 2426/275dia on the horn
to not be guessing quite so much... especially if the goal is a turnkey crossover that could have a major
effect on the enjoyment of what should really be a nice system.

[Bernard Wolf]

1) will a 2426 body + 275nd diaphragm have the same level and response as a stock 275nd?my -guess-: minor difference in amplitude overall (1-2dB looking at Zilch's simulated crossoverplots comparing the LF drive levels), and a HF response that may not roll off as quickly(see #3 below).2) would the resonances that are being specifically compensated for in the MkII crossover thesame level and frequency be the same with the 2426/275 combo, and are they primarily due to the horn?my -guess-: maybe and probably... I would think the peaks being compensated with the parametric-likesections (notch filters) could be pushed around a small bit, but if major driver resonances of the horn/driver combo are off, a larger section of the desired response in the crossover area could be off target.3) what effect on response did plating the pole piece in copper have other then "high frequency extension"just have general words from the brochures, no response plot or spec for this.It would really be helpful to have a local buddy run FR plots with both 275nd and 2426/275dia on the hornto not be guessing quite so much... especially if the goal is a turnkey crossover that could have a majoreffect on the enjoyment of what should really be a nice system.

Thanks for the input Grumpy..there are so many variables here that if makes it very difficult to get a handle on it all. The other problem is that speakers are heavy - 130lbs - and that to get the 2526 out I have to take the bass driver out, undo the horn and then of course put it all back together again.

I kind of kick myself for missing out on a pair of 275nd's that sold on ebay recently for $750.00 CAD. Thing is I had just spent money on a new camera and couldn't justify the expense and of course had I bid, who knows were the price may have gone. That and the fact that I really did not want 2 275's. God damn it, why can I not find one (1) 275nd??!! that would be the ticket!

In the meantime I am still talking to Solen. His latest:

Sir,If you are not using the original drivers meant for this X-over design, we can do a custom X-over design based on the drivers you are actually using.RegardsProblem is he would probably want me to bring the speaker to him.

[Robh3606]

Sir,If you are not using the original drivers meant for this X-over design, we can do a custom X-over design based on the drivers you are actually using.RegardsProblem is he would probably want me to bring the speaker to him.

Hello Bernard

If it doesn't buyer beware. I would also not put a potentiometer in the mix. Stick with the fixed values unless you want to try to figure out where your system set point should be compared to the original. I doubt a third party is going to do a better job than JBL did with the original crossover. Different designer different compromises so no guarantee the new crossovers will sound better could be just different. If they don't actually have the speakers then it's all simulation with no actual listening. I also doubt they have the measurement capability that JBL has even if they did. You would need a full set of polar measurements on the horn and woofer to have any chance of matching the crossover already in there.

Rob

[Bernard Wolf]

Thanks Rob, I hear what your saying. For sure if I had 275nd's complete and was changing everything to MKII configuration I would find someone to do it exactly as specified.. no question. As what I am/was considering is a bit of a mish mash I don't know how important that would be... assuming it all worked out well.

More and more though, I think I will likely just have Solen build me a new and improved network for the original set-up. Perhaps once I do that then of course I will find that single 275nd ... that would really make my day!

Thanks to all for your input... sorry to have rehashed this once again but that itch will not go away. I think you all know that feeling.

Bernard

[Earl K]

Hi Bernard,

Give me a few days to talk-you out of this madness ( buying custom crossover from Solen based on the S3100 network ) .

In the meantime ( I'd suggest that you ) , ponder & reflect on the info contained in ;

275nd Diaphragms ( for instance, pay attention to Pascal's & Korgroenewoud's observations )