Tweaking 5b x-overs

heiney9
heiney9 Posts: 25,194
edited July 2007 in DIY, Mods & Tweaks
I have some free time this week and while I am very happy with my 5b's since doing the x-overs (Solens, Mills, etc) and the RD0's, they still aren't voiced exactly how I'd like them. I'm looking to get close to the same voicing as my wonderful SDA 1C's (sans the SDA part).

These are fused rather than using a polyswitch. The schematic replaced the 2.0 ohm with a 2.7 ohm resistor when using a polyswitch. My guess is the poly adds 0.7 ohms of resistance ????. These originally had 2.7 ohm resistor and I replaced with a 2.0 ohm (not really all that different).

These are not harsh or shrill or edgy, but they are very forward and "in your face" I'd like to tone down the output of the tweeter to have it sound a bit more laid back, like the 1C's. How do I accomplish this w/o completely **** with the x-over too much?

I have a 2.7 ohm Mills which I was thinking of running in parallel with
the 2.0 ohm already in the signal path of each tweeter. My Ohms law is a bit sketchy, so if I remember, running 2 resistors in parallel *sums* the value, so then the resistance becomes 4.7 ohms. Would it be better to get a single resistor of the correct value?

Will this alone be enough to make the tweeter a bit more laid back in the circuit? What draw backs, if any? Will this even make a difference? Any other ideas? I'm also considering bypassing the Solen cap in the signal path to the tweeter with a Platinum Sonic cap. Maybe this will help, maybe not.

My 1C's are just so much more laid back and effortless. I'm looking to get some of that in my office/computer rig. Bass and mids are great as, well a soundstage, etc. The problem with these older Monitor series is the tweet produces so much of the upper midrange freq as well as the highs so I'm sure that's why these sound so forward.

Any advice is appreciated.

H9

I'm sure perhaps the gear plays a very small part in the sound being on the bright side, but this is a second system and I'm not running out and swapping gear.
"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

Comments

  • engtaz
    engtaz Posts: 7,663
    edited July 2007
    Ohms law resistor in series add and parallel divides
    engtaz

    I love how music can brighten up a bad day.
  • heiney9
    heiney9 Posts: 25,194
    edited July 2007
    Come on speaker guru's help me out here. I know it's a holiday so perhaps people are busy.

    Thanks engtaz, I Googled and got my learn on. Looks like if I'm going to change resistor values it's best to get (1) of the correct value rather than to run them in series.

    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!
  • Jockos
    Jockos Posts: 310
    edited July 2007
    I would try using a different cap in the tweeter circuit. You could problaby just change 1 12uf and see what a difference it makes.

    Jockos
  • Systems
    Systems Posts: 14,873
    edited July 2007
    If it is only the very top end (>8k-10k) that needs to be tamed then adding an RC network across the voicecoil should help.Otherwise increasing the series resistance would be your best bet.I agree it is best done with a single resistor but you can experiment by adding them in series until you hit on a value that seems to be right.Then purchase a single one of that value.Other than output level adding a few ohms in series with the tweeter should not alter the crossovers response much.
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