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View Full Version : Is biasing the N250TI network worth it in 2016?



kelossus
04-12-2016, 11:36 PM
While waiting for my 250TI's to arrive I have been contemplating potential upgrades.

I always intended to bias them but came across a thread where 4313b mentioned that when using Sonicaps there is no need to bias. A quick search regarding this brought up this thread

http://www.audioheritage.org/vbulletin/archive/index.php/t-37060.html

Which yielded no answer to the question initially asked. If I use higher end Jantzens/Mundorfs/Sonicaps is there a need to bias????

I would rather keep the network simple and spend dollars on wax coils if there is no need to bias.

I have a pair of biased L212's and the difference was not subtle but used Jantzen crosscaps, nothing special.

Wagner
04-14-2016, 01:33 PM
While waiting for my 250TI's to arrive I have been contemplating potential upgrades.

I always intended to bias them but came across a thread where 4313b mentioned that when using Sonicaps there is no need to bias. A quick search regarding this brought up this thread

http://www.audioheritage.org/vbulletin/archive/index.php/t-37060.html

Which yielded no answer to the question initially asked. If I use higher end Jantzens/Mundorfs/Sonicaps is there a need to bias????

I would rather keep the network simple and spend dollars on wax coils if there is no need to bias.

I have a pair of biased L212's and the difference was not subtle but used Jantzen crosscaps, nothing special.
I may be mistaken, but I do not believe 4313B has ever suggested that a biased network is not an improvement, in fact quite the opposite

That thread you linked to doesn't appear to suggest that either, it is a discussion of the bias voltage and if "boutique" caps offer any advantage over less ambitious (read: reasonably priced) alternatives in either design but primarily in charge coupled executions

That, and the frequently encountered wishful thinking (aloud) that somehow, if one were to spend enough money on caps, and NOT charge couple them then that would prove superior to charged coupled designs

The evidence would suggest that not to be the case. These (this) question comes up routinely and generally does not end well

One poster ("NickH") is the only one who seemed to have a different purely anecdotal opinion despite the evidence provided, by Greg Timbers, numerous threads here delving deeply into the type and even the actions of JBL

Much energy is spent by many in attempts to "theoretically" explain away the advantages of charge coupling and often by folks who have never even given it a try, a build or a listen

I guess, in all fairness, maybe Nick can't discern a difference and that's fine too. From what I can gather (and I may be wrong on this one too), "NickH" has never heard, built or owned a system employing charge couple network and arrived at his conclusions from what he has "read and heard" (again, based upon his remarks).

That obviously doesn't prove anything though as I am certain there are numerous speaker systems in this world on which a charge coupled network would be a waste of time and money anyway as well

Solen and to some extent Dayton appear to be the cap of choice for most of these implementations

300_Summit
04-14-2016, 02:53 PM
I always intended to bias them but came across a thread where 4313b mentioned that when using Sonicaps there is no need to bias. A quick search regarding this brought up this thread

.

I believe (I could be mistaken) 4313B (Giskard) was referring to not needing to use bypass caps with Sonicaps. If 4313B (Giskard) did say "biasing was not necessary", it was probably laced with a substantial amount of sarcasm :)

Ian Mackenzie
04-14-2016, 02:54 PM
While waiting for my 250TI's to arrive I have been contemplating potential upgrades.

I always intended to bias them but came across a thread where 4313b mentioned that when using Sonicaps there is no need to bias. A quick search regarding this brought up this thread

http://www.audioheritage.org/vbulletin/archive/index.php/t-37060.html

Which yielded no answer to the question initially asked. If I use higher end Jantzens/Mundorfs/Sonicaps is there a need to bias????

I would rather keep the network simple and spend dollars on wax coils if there is no need to bias.

I have a pair of biased L212's and the difference was not subtle but used Jantzen crosscaps, nothing special.


Context can be a wonderful thing as can rational thinking.

At the time there was a trial and error with bypassing capacitors and sonic caps were discussed.

JBL were bypassing polyester capacitors with 0.01 uf polypropolyn capacitors

This is how Sonicaps were used.

In diy there is no consistency but in production there is and JBL has provided a working cc network that they are happy with.

Will the other alternatives perform the same or different to the CC Solen network?

I think Greg was actually asked this,question once and it comes down to the budget.

If you care to check the prices the cost of a network like this can blow out to rediculous sums for what is the law of dismissing returns.

The choice is yours

kelossus
04-15-2016, 01:03 AM
This is the quote from Giskard:4313B
09-27-2004, 10:26 PM

The bypass capacitors go a long way in improving the performance of the larger capacitors.

One can also use charge-coupled Solen capacitors to great effect.

The most expensive route is to replace all the stock capacitors with SoniCaps. They don't require charge-coupling or bypass capacitors.




From this thread: http://www.audioheritage.org/vbulletin/archive/index.php/t-3330.html

I was also under the impression that if you are using a decent polycap like Solens or Jantzens once charge coupled there would be no difference. Jantzens are just easier for me to source locally and would work out cheaper than international freight.

Also are wax coils a benefit? Particularly in the Tweeter and Mid-range networks?

Allanvh5150
04-15-2016, 01:29 AM
I can never understand why one would not bypass any larger value capacitor. It makes good sense as it has the effect to cancel
the capacitors inductance.

Allan.

pos
04-15-2016, 02:02 AM
I was also under the impression that if you are using a decent polycap like Solens or Jantzens once charge coupled there would be no difference. Jantzens are just easier for me to source locally and would work out cheaper than international freight.
You can try searching for SCR caps. This is the compagny that produces them for Solen:
http://www.toutlehautparleur.com/condensateurs-scr-serie-pa-pb-et-ppe.html

kelossus
04-15-2016, 02:50 AM
Ok I found an Australian distributor for the SCR fast caps but they are nearly twice the price. A 20uf is 24.46 and the Jantzen equivalent is 12.00.

EDIT:

Just checked the US prices for a 20uf and it is roughly $10aud, then you factor in shipping and it will work out more costly.

If the Daytons and the SCRs are commonly used why not the Jantzens? They are well made....I think....

kelossus
04-15-2016, 02:55 AM
Context can be a wonderful thing as can rational thinking.

Will the other alternatives perform the same or different to the CC Solen network?

I think Greg was actually asked this,question once and it comes down to the budget.

If you care to check the prices the cost of a network like this can blow out to rediculous sums for what is the law of dismissing returns.

The choice is yours

I am more then aware the costs of building networks. The biased 250TI network works out to around $1100 and that includes wax coils for tweeter/midrange, air coils for midbass, p-core for woofer. MOX resistors and obviously the capacitors.

Ian Mackenzie
04-15-2016, 05:16 AM
Okay

Go for top of the range Mundorf Silver /Gold Oil and figure out the prices?

Some years ago l spent around 18 months testing and evaluating capacitors from a stock bypassed JBL crossover, the best Mundorfs to Auricaps to Clarity SA caps, bypassed SA Clarity caps with 0.01 Auricap, bypassed polyester with polypropolyne, and Charge Coupled Solen Fast Caps.

I also purchased a reference Lavry DAC and hi end directional digital coaxial cable as a base line.

Electronics Pass Labs

What l gained from the experience is that engineers like Greg do things for a reason.

Why. It ultimately comes down to the voicing of the overall system and getting that right for a given end market.

This is a real challenge.

With voicing everything matters including parts in crossovers.

Some drivers might work well with bypassed caps and certain brands and part numbers. Ie soft dome /paper drivers compared to hard dome metal diaphragms are a totally different animal and things change when you use acquaplas dusted titanium and beryllium. Getting particular brands of caps to match drivers is not trivial and bypassing just complicates the the process.

The Charge Coupled Fast Cap Solens worked brilliantly and complimented the JBL driver sound in my evaluation.

4313B
04-15-2016, 08:35 AM
Greg Timbers did two pairs of charge-coupled 250Ti networks for his friends and the results got rave reviews.

Wagner
04-15-2016, 09:13 AM
"kelossus", are you
Asking a question?
Arguing a point(s)
or, just sharing your decision making process (internal struggle) out loud with the forum?

I am confused because of the ancient quotes you have dug up which appear to substantiate the way you are (or want) to lean

Do you already own anything that's charge coupled?

If you are finding it difficult to make a decision then just run your speakers with "regular" networks and see how it goes and then make a decsion after the jitters have died down, that, or make the decision to trust Greg Timbers and 4313B and just go for it

The only negative with the later is that you won't have had the opportunity to experience the difference the CCing made

Oh, and don't piss away good money on ridiculously priced boutique caps, 99% of it, 99% of the time is :bs:

4313B
04-15-2016, 10:25 AM
This is the quote from Giskard:4313B
09-27-2004, 10:26 PM

The bypass capacitors go a long way in improving the performance of the larger capacitors.

One can also use charge-coupled Solen capacitors to great effect.

The most expensive route is to replace all the stock capacitors with Sonic Caps. They don't require charge-coupling or bypass capacitors.




From this thread: http://www.audioheritage.org/vbulletin/archive/index.php/t-3330.html

I was also under the impression that if you are using a decent polycap like Solens or Jantzens once charge coupled there would be no difference. Jantzens are just easier for me to source locally and would work out cheaper than international freight.

Also are wax coils a benefit? Particularly in the Tweeter and Mid-range networks?Yes. Jeff at Sonic Craft and I had a decent conversation about that way back then. I think if you search other posts for the N250Ti charge-coupled networks I built many years ago you will see that they all used Solen parts.

The short story ends up being that I nearly always charge-couple Solen capacitors (although just last weekend I took apart a pair of 4365 networks where I had used all Janzten Cross-Caps instead of Solen capacitors).

Ian Mackenzie
04-15-2016, 11:58 AM
From Post by Giskard in link above

Again, I have to warn anyone who wants to start modifying stock filters that JBL does extensive listening evaluations of their systems and changing capacitor dielectrics or inductor DCR values from stock can yield really good results as well as really bad results.

I completely agree as stated in my earlier post.

In theory you could argue that if you had enough JBL DX1 active crossovers and made the necessary changes to match the voltage drives it would make an interesting baseline to evaluate the impact of crossover capacitors. I would not be surprised if Greg has already done that.

kelossus
04-15-2016, 02:12 PM
From Post by Giskard in link above

Again, I have to warn anyone who wants to start modifying stock filters that JBL does extensive listening evaluations of their systems and changing capacitor dielectrics or inductor DCR values from stock can yield really good results as well as really bad results.

I completely agree as stated in my earlier post.

In theory you could argue that if you had enough JBL DX1 active crossovers and made the necessary changes to match the voltage drives it would make an interesting baseline to evaluate the impact of crossover capacitors. I would not be surprised if Greg has already done that.

Hmmmm......if DCR is such an issue shouldn't all the DCR's in the biased N250TI network be listed? In the past I have always gone for low dcr coils even when using wax or air. I will never use anything with a DCR of >0.5ohm unless the inductor is specified otherwise. I thought this was enough.

Also do the Solens Fastcaps and Daytons dielectrics match or come close too the original?

kelossus
04-15-2016, 02:13 PM
Yes. Jeff at Sonic Craft and I had a decent conversation about that way back then. I think if you search other posts for the N250Ti charge-coupled networks I built many years ago you will see that they all used Solen parts.

The short story ends up being that I nearly always charge-couple Solen capacitors (although just last weekend I took apart a pair of 4365 networks where I had used all Janzten Cross-Caps instead of Solen capacitors).

Do you use the Solens because they are cheap and effective or, in biased networks are they clearly superior?

4313B
04-15-2016, 02:21 PM
Do you use the Solens because they are cheap and effective or, in biased networks are they clearly superior?All the above. If I could afford to charge-couple $100 boutique capacitors I would use them instead. What I am not going to do is use $100 boutique capacitors unbiased. Greg told me a few years ago - "I don't even bother wasting my time listening to unbiased networks anymore." Yeah, I get what he is saying.

Unfortunately I have wasted my time listening to unbiased networks and I prefer biased. I even biased my Tannoy networks. That was a hoot and a holler! :yes:

But... I also have first hand experience in biasing 250Ti's and to me it is a real PITA so I can certainly understand any hesitation taking on the task. You couldn't pay me enough money to build another pair of biased 250Ti networks. :p

Ian Mackenzie
04-15-2016, 02:47 PM
Why not just use your N250Ti as stock for a while and enjoy them for what they are.

I think the rational for any desire to amend the crossovers will be a lot clearer then.

If you do open them up it will become immediately obvious then as to whether you will be bothered to proceed on the path to build new charge coupled networks.

kelossus
04-15-2016, 02:53 PM
All the above. If I could afford to charge-couple $100 boutique capacitors I would use them instead. What I am not going to do is use $100 boutique capacitors unbiased. Greg told me a few years ago - "I don't even bother wasting my time listening to unbiased networks anymore." Yeah, I get what he is saying.

Unfortunately I have wasted my time listening to unbiased networks and I prefer biased. I even biased my Tannoy networks. That was a hoot and a holler! :yes:

But... I also have first hand experience in biasing 250Ti's and to me it is a real PITA so I can certainly understand any hesitation taking on the task. You couldn't pay me enough money to build another pair of biased 250Ti networks. :p

Is it the size of the crossover or all the bus bars that make it a pain in the arse?

I had the Jantzen distributor in Australia bias my L212s and he didn't complain too much. They even fit on a piece of mdf where the original ones are. I didn't use any fancy or huge coils in them so it was a relatively small build.

Strangely my L212's had two different stock networks.

70942

kelossus
04-15-2016, 02:57 PM
Why not just use your N250Ti as stock for a while and enjoy them for what they are.

I think the rational for any desire to amend the crossovers will be a lot clearer then.

If you do open them up it will become immediately obvious then as to whether you will be bothered to proceed on the path to build new charge coupled networks.

Absolutely mate, I do intend to listen to them for a while before biasing them. I rushed into it with my L212's but the effects were still noticeable.

On a side note I will now own 3 pairs of GT 4-ways (I think you could count the L212's as 3-ways, I use them with a pair of 2203 subs anyway) 4315B's, L212s and 250TI's. Yay for me. The 4315's have proved to a be a real hard speaker to drive, my tube amps couldn't cut it. I needed to buy a Classe power amp to handle them.

After the responses so far I will most certainly build biased networks for them at some point, wax coils and all.

Wagner
04-15-2016, 03:18 PM
What the hell is a "wax" coil?
I think I've read it here now about five thousand times

kelossus
04-15-2016, 03:40 PM
What the hell is a "wax" coil?
I think I've read it here now about five thousand times
Wax-Coil The ultimate audio inductor.
The coil is wound from 99.99% pure copper foil on a hardwood core.
Interleaved with a layer of 60µm quality paper that is impregnated with polymolecular parrafin wax.
This results in a coil that is hard as a rock.
Each coil is then tested with a Clio system.


70943

4313B
04-15-2016, 03:48 PM
I had the Jantzen distributor in Australia bias my L212s and he didn't complain too much.I used all Jantzen parts in my 4365 networks, including those coils. I have nothing bad to say about them.

kelossus
04-15-2016, 04:49 PM
I used all Jantzen parts in my 4365 networks, including those coils. I have nothing bad to say about them.

Do you think the Solens would have been better in the 4365 networks, interested why you chose Jantzens.

I think there coils is where the excel. For the price and quality they are hard to beat.