Just a quick capacitor application question

heiney9
heiney9 Posts: 25,197
edited February 2012 in DIY, Mods & Tweaks
I am getting ready to purchase the final parts to upgrade the x-overs in a pair of RT25i bookshelf speakers.

Schematic here

http://www.polkaudio.com/forums/attachment.php?attachmentid=18701&d=1155781569

For the low pass, obviously these don't go that low because of the driver size, how much influence on the overall sound does the 27uF cap have? Does it affect more midrange than bass? The reason I ask is I was going to buy AXON 27uF caps since they are economical. If that 27uF cap has a lot of influence on the voicing of the speaker I suppose I could step up to a better cap. I am using Clarity APW for the high pass section. The parts need to be an improvement, but also economical and as physically small as possible.

My other thought is to just do the high pass and leave the rest? Any opinions on that?

Thanks

H9
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
Post edited by heiney9 on
· Share on FacebookShare on Twitter

Comments

  • heiney9
    heiney9 Posts: 25,197
    edited February 2012
    FWIW, I am super impressed with these little bookies, they do so much right. I am amazed at the sound that comes from these. I think they are more neutral than the RTi38's I also have been demoing. Impressive little speaker and I don't want upset the balance, but they are just a tad ragged on top. I am hoping a better cap and Mills resistor will correct that.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • CoolJazz
    CoolJazz Posts: 570
    edited February 2012
    Looks like a resonate trap. So maybe not quite as audible as the main filtering caps, but I wouldn't say invisible at all either.

    Don't know that helps so much...

    CJ

    PS...wouldn't be involved with the ragged your talking about i don't think.
    A so called science type proudly says... "I do realize that I would fool myself all the time, about listening conclusions and many other observations, if I did listen before buying. That’s why I don’t, I bought all of my current gear based on technical parameters alone, such as specs and measurements."

    More amazing Internet Science Pink Panther wisdom..."My DAC has since been upgraded from Mark Levinson to Topping."
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,197
    edited February 2012
    CoolJazz wrote: »
    Looks like a resonate trap. So maybe not quite as audible as the main filtering caps, but I wouldn't say invisible at all either.

    Don't know that helps so much...

    CJ

    PS...wouldn't be involved with the ragged your talking about i don't think.

    No the raggedness is in the high pass. I just am not sure on small speakers if the low pass section has a large influence on midrange as well.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited February 2012
    CoolJazz wrote: »
    Looks like a resonate trap.
    It's a Zobel for impedance equilization plus forming the shunt leg of the low pass section.
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,197
    edited February 2012
    FTGV wrote: »
    It's a Zobel for impedance equilization plus forming the shunt leg of the low pass section.

    You think using a premium poly cap would have much influence vs. a budget poly cap like the AXON? Or maybe just leave it be and concentrate on the high pass?

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited February 2012
    heiney9 wrote: »
    You think using a premium poly cap would have much influence vs. a budget poly cap like the AXON? Or maybe just leave it be and concentrate on the high pass?

    H9
    IMO a budget poly would suffice in the low pass section.Another budget option. http://www.erseaudio.com/MPX25-03-27-00 I'm going to be trying some of these soon in both hi and low pass sections.
    · Share on FacebookShare on Twitter
  • CoolJazz
    CoolJazz Posts: 570
    edited February 2012
    FTGV wrote: »
    It's a Zobel for impedance equilization plus forming the shunt leg of the low pass section.

    Thanks...that was what I was thinking of and had brain freeze and couldn't think of the term Zobel. It'd most likely be keeping some control at the port freq wouldn't it?

    CJ
    A so called science type proudly says... "I do realize that I would fool myself all the time, about listening conclusions and many other observations, if I did listen before buying. That’s why I don’t, I bought all of my current gear based on technical parameters alone, such as specs and measurements."

    More amazing Internet Science Pink Panther wisdom..."My DAC has since been upgraded from Mark Levinson to Topping."
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited February 2012
    CoolJazz wrote: »
    It'd most likely be keeping some control at the port freq wouldn't it?
    When placed across the voice coil of a woofer it reduces the inductance that causes impedance to rise as frequency increases.Basically making the driver look more like a resistor to the crossover by making the impedance of it's voice coil more linear.
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,197
    edited February 2012
    Thanks Fred, I know Solen and AXON are essentially the same cap. Isn't Erse made by the same factory as well? Now it's a toss up between those two, because the Solen of the same value (except higher voltage) is twice the price of the AXON and Erse. I had Solens in the high pass of my 5B's and I like the Clarity PX much better for my situation.

    I don't think Parts Express sells a Dayton in the exact value I need. I'll have to check again.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • FTGV
    FTGV Posts: 3,649
    edited February 2012
    heiney9 wrote: »
    Thanks Fred, I know Solen and AXON are essentially the same cap. Isn't Erse made by the same factory as well?
    Im not sure if ERSE also sources from SCR like Axon and Solen.I think either would suffice for low pass duties.
    · Share on FacebookShare on Twitter
  • VR3
    VR3 Posts: 28,748
    edited February 2012
    I have used the Pulse X from Erse with positive results... very nice caps...

    I have no used Axon though ---
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
    · Share on FacebookShare on Twitter