for experts with caps in speaker filters

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Hi,

happy owner of a pair of the fabulous american Boston Lynfield 400 L speaker for 15 years, I can't live with them anymore. They don't fail in transparency, soundstage but fails in life, juicy treble, they are like ghost: flesh is missing (the curve is very flat between 300 htz and 20 khz)
I find my little kef 104/2 with all its defaults to be more natural : more flesh and meat, a lively mid-bass fantastic with rock (more important for me than a boomy 35 htz in our Domus), a mid and treble that match good with wood and brass instruments (jazz and classic).

Well, the Lynfield are second hand, I open it one month ago and change the damages than the first owner done with changing most of the original MIT Wires with QED profil silver... Stupid because Qed doesn't match with the very clear aluminium mid and treble units of Boston Audio company.

the question is cooming soon:eek:. So Then i change the Qed with the white internal 2,5 mm² Oyaide PCOCC-A, it's a honnest brand according to me, I'm happy with their 750 across (good Q/P) interlink. Speakers wires are the little first blue Cardas : honnest bass, lively, transparent, just a little too much klimbing treble but it's ok.

I want change the caps of the 4° order treble filter and some caps of the 2nd order mid. And maybe the industrial Colber cement resistors.

the question is : is it good to change a cement resistor with an non inductive wirewound one like a Mundorf Suprem resistor. The impedance is not the same when the frequency grow up between a cement and a wirewound (The Boston designer is famous, and maybe it's not by chance that he used cement in this top line speaker?) The cement one do better with reducing the impedance curve when the frequency grows and not the non inductives wirewound resistor ? true or false ?

For the caps. in the mid : after 2 x 4 homs // Colber cement resistors, I have Two Boston chimical caps (200 uf & 60 uF) in // with a little famous polystyren MULTICAP RTX of 0,1 uf/100V. All this folk give a transparent result but with a lake of life and meat (the mid goes 125 htz to 3,5 khtz). Is it good for example to change the 60 uf with a Mundorf Suprem (for flesh according for example Humble Homemade Hifi) or an ESA clarity caps which is known to be rounder than others brand ? Is it good to match chemical with mkp in // (resonances?) ? What about the little MIT caps ? (very neutral and transparent but without life... a cold side ?)

For the treble, it beginns with a 4 homs resistor// with an 1 uf Mylar yellow Efco CPM88/160 V (mylar because too little to be MKP, then 8 (boston Mylar +6 uf (Efco mylar) with a Multicap RTX, then an inductor to the minus, then 4,7 mylar + 2 uF MKP with a MIT RTX. Here I believe with first an 8 uF MKP Amphom aluminium (because I have already it) with maybe 4,7 something fleshier : Mundorf Suprem ? and for the second : 4,7 uF Mundorf Suprem or red jantzen superior Z cap and for the the 2 uf maybe clarity caps MR or true copper Audyn caps, for the RTX MIT0,& uf a benchamark with Mundorf a silver oil...

Any experiences with MKP caps for meatier and fleshier results without laking in natural and transparency (aluminium cones) and what about resistors : better cement or non inductive wirewound (I also think in a Kiwame for the treble)?

I can't try everything because of money, advises of seniors :) is needed please and sorry for the long post and description? I am a believer than wires and filter are the last 30% of the final result of a good speaker after the matching between box/charge/speaker units but the 99% chronophag and costly part of it...

regards

PS: one day when the money goes better I try the Stigerik way : activ with B&G and no box bass in two way design...

Eldam
 
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Money short,
I would change/test (upgrade) caps for the tweeter in first.
I would leave resistors if in order/not damaged. (posterior upgrade/more money)
I would check if there is a need for caps in the mid, because, they can give a drastic change in sound for better, or not.
At the same time I would pad the tweeter a little, if there's the need for it... that could be done with a new good quality n.i. resistor.
(Members would appreciate to see some picture of the crossover, if possible post the layout you mention.)
 
Thank you for your reply,

Two resistors of the mid are damaged during the change of the internal wires (legs broke in one of the mid filter) so I have to change it with the original cement Colber or same technology in an another brand or change technology with non Inductive or colored like Kiwame for example.
With your last point I can try to take the two Colber resistors of the tweeters (one in each tweeter filter) and rebuild the two resistor in the damaged mid filtezr and try another resistor for tweeter. these tweeter klimb to 30 K htz... my ears at 44 are nearer to 16 khtz...

Thanks for the advices of experienced fellow because i Know that you can move everything wuth a small change : you change the tweeter filter : bass can go fat, etc, etc. And I never play with filter...just read litterature :)

PS : I take photographs and draw a scheme, you are right.
 
sheme and photographs : the scheme is good some 0,1 uf rtx caps are missing in the photographas but are in every celluls (// and series)of the filters.
Only mistake on the sheme: in the last mid cellul between + & -, there is a MIT RTX 0,1 uF in // with the 10 UF (chemical Boston cap on the left on the third picture... only visible on the sheme)
brands are Boston, Efco and unknown (the 2 uF in the last treble cellul), resistors are industrial Colber cement in paper body.
Big mid caps are Boston chemical like trhe 10 uf near it between + & minus for the mid.
In the second photograph there is a missing MIT RTX 0,1 uF to show the valor of the 2 uF cap (mylar?)
 

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Administrator
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Changing brands and types of caps is only "icing on the cake" as the Anglophones like to say. You will get far greater results by changing the values of the caps. And that may be your problem. Of course you need some experience and maybe some measuring equipment to guide you, and that's not easy.

Do you know what the original values of the crossover were? If you do, that is the place to start. Rebuild with decent quality caps like Solen or Jantzen and hear were you are. From there, you can tune as you like.
 
Thank you for the input Pano,

The values are the originals. The first owner changed only the wires.
I m sad i believed caps was more than the 1% on the pudding.
I don t want to change the values choosed by the experienced designer.
Just change the quality of the caps...but if it s impossible to add flesh and meat with them...it s à no go.
What about resistors?
Cheers
 
diyAudio Moderator
Joined 2008
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Resistors produce minor distortions. Types mainly, more than brands. Where it is audible at all, the effect is often less noticeable than a capacitor with issues, maybe moreso than the difference between various good performing capacitors though.
 
Thank you Allen B,

So the originals broken Colber cement can be changed by cement dayton for example : it's almost equal and cost nothing in relation to a 20 more costly Mcap suprem resistor:).

Is it a good idea to test Kiwame or Allen Bradley used in powersupply for a filter to introduce some decent (pleasent?) distorsions at the beginning of the filter (my sheme) ? minor change or could it warm the sound (Kiwame?).

Many mylar are used in the original speaker with bypass polystyren.
With the same values where coul be the major change (into the icing on the cake): changing the bypass 0,1 uF polystyren or the high value of the mylar caps (MKT) by decent MKP (jantzen, audyn cap, mundorf).

Mixing a MKP with an chemical in the mid = too much minor change (polish the icing on the pudding?) ? Bad idea?

The goal for me is not to buy one thousand dollars in caps:dunno:.

Are the informations at Humblehomemadehifi just marketing for pushing the sells or buying by brands or serious informations ?
 
Can anyone seriously explain me what the hell effect can cause in any audio system, to change a brand of one cap to another, or between cable brands, supposing similar ELECTRIC and MECHANICAL characteristics???

In both cases, if there is any audible difference is because you are using a bandpass filter in place of a capacitor or cable...
 
It's like human : same genome but not same clever or face !

Or with a picture analogy : Igazu falls and a small river are water but it's not the same shower... or the french wine and argentin wine (except Carmenere:) hmmm I like it we have not in france!)

try yourself, and you will see there are difference; experience is needed because the mathematical model (resistance, reactance, inductance, material loss, etc) are too complex to use for setting a speaker or an analogic stage for example. That's why i ask for experienced fellow in design speaker and filter their help... The analogy with the words : flesh, meat, clear, etc can help me if the experience of the good designers of DIYA say it's valid.... or not. I already know that there is a small difference (ice sugar on the cake theory= kirsh on the pudding in france)... but I know sometimes that this small difference can transform a material in something listenable (the signification of the ice sugar or kirsh on the cake : the little change give all the final taste and character of the product but if the cake is burn inside, the caps on the pudding don't save the cake for stomach problems!)
 
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Administrator
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Some people do not like Mylar caps. Polypropylene is measurably better. Get some of those of the same values, replace all the old ones and have a listen. As I said before, Solen or Jantzen will be just fine. No need for fancy caps.

I really do think you'll have to actually change values to get what you want.
 
Some people do not like Mylar caps. Polypropylene is measurably better.

I disagree. I would say measurably different. Visit here for the test data.

Effect of Film dielectric type on capacitor ESR

It may be the lower ESR of PP film caps is more audibly noticeable than PET, thus more recognizable as a slightly brighter change that's construed to be 'better'?
 
Thank you Pano,

I have already some caps : 8 uf Amphom MKP aluminium, some 1 uF Audyn superior + caps, some french SCR (= basic Solen). I will do like you say to looking for an audible difference...better or worse...or no difference.

In the same time I need to change the resistors of the mid (two 4 homs are broken during soldering the new Oyaide copper wires), i will go for non inductive to try to padle and with the Tweeter resistor too (first cellul of the tweeter filter)

I will never try to change value of the filters for some reasons : mid and tweeter units were developed from scratch by Boston Acoustics and the filter by the designer who knew what he done (I hope). I have no experience in tweaking filter : no way to do better myself with diferent values : I prefer to go on a new speaker project and sell the Lynfield 400 L.
I like the sound of the Kef 104/2 I have, they are less transparent, but "meatier" and more musical according to my taste, but I never saw the curve (anybody measure it?) : i surmise that the good result with these speakers is a diving treble, a nervous mid bass with no bass (- 2 db : 50 Htz - 20 Khtz ...maybe - 6 db at 40 htz or 35 htz???). The filter is very complex !

On another side I heard the Lynfield for 15 years !
thanks again Pano
 
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Some people do not like Mylar caps. Polypropylene is measurably better. QUOTE]

I disagree. I would say measurably different. Visit here for the test data.

Effect of Film dielectric type on capacitor ESR

It may be the lower ESR of PP film caps is more audibly noticeable than PET, thus more recognizable as a slightly brighter change that's construed to be 'better'?

Hi and thank you for the input and link,

Is PET equal to mylar and equal to MKT (they are the same?)

For my taste, brighter is not better. Hummm I have to test before wasting money in the missing MKP value caps...

In the output stage of a cdplayer I notice great difference between different caps (used for stop DC or do filter) but never try with speakers.
 
Hi and thank you for the input and link,

Is PET equal to mylar and equal to MKT (they are the same?)

For my taste, brighter is not better. Hummm I have to test before wasting money in the missing MKP value caps...

In the output stage of a cdplayer I notice great difference between different caps (used for stop DC or do filter) but never try with speakers.

PET is = to mylar is = to MKT
MKT caps offer a sonic signature not much different than non-polar electrolytic crossover caps due to their relatively higher ESR. So, if you are replacing NPE's with MKT's the voicing should not change significantly. However, if you replace MKP's with MKT's then you'll notice a softer high end due to the higher resistive effects of the MKT caps.
 
Well... the Boston acoustic designer knew what he done ! After all there are too a lot of electrochemical and some mkt in the Kef too ! I knew somebody who played with silmic 2 (100V) in filters !

The treble is soft but with no consistance... so Pano is right I have to move the curve with different value or add notch, etc... so it is a no go for me, I will just try non inductive resistor because I need to change them... (but if somebody say to me that non inductive resistor has not the same result with impedance curve than cement one; I read something like that in the past ?!).
So is it ok : non inductive resistor can give a slighty softer effect, or I forget it too and buy just fifty cents Dayton cement ?

Thanks guys... my next big step in DIY audio will be : activ speaker but from scratch.
 
If there exists differences between capacitor of the same capacitance and voltage values, is because one of them is not a true capacitor, it may have higher ESR or ESL (Or any other parasitic) values, in fact the worse they are, the capacitor will be a band pass filter in place of a capacitor. Since here the audible (¿?) difference.
 
If there exists differences between capacitor of the same capacitance and voltage values, is because one of them is not a true capacitor, it may have higher ESR or ESL (Or any other parasitic) values, in fact the worse they are, the capacitor will be a band pass filter in place of a capacitor. Since here the audible (¿?) difference.

And piezo electric effect. These thin films flex under load within the cap. Different base materials have different effect upon the operating part affecting it sonically. So yes caps act like tweeters, distorting the sound. The best of the best caps minimize this.
 
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