RTA 11T Crossover Frequency
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Hi,
For fun, I did a frequency sweep on my RTA 11T pair using an Android frequency generator app.
The tweeters played down to 1.5KHz and did most of the work at 2KHz. The MWs were quite audible at 3.8KHz and played up to 4.3KHz (although with decreasing loudness). Both speakers performed quite identically. I had replaced the electrolytics with like values and the polyswitch with 0.5ohm resistor. Everything else is original. I used kitchen towel tube and pillows to isolate the drivers sounds.
I think this is too much overlap for a 2nd order 3 KHz crossover. Would you agree? Is something wrong?
For fun, I did a frequency sweep on my RTA 11T pair using an Android frequency generator app.
The tweeters played down to 1.5KHz and did most of the work at 2KHz. The MWs were quite audible at 3.8KHz and played up to 4.3KHz (although with decreasing loudness). Both speakers performed quite identically. I had replaced the electrolytics with like values and the polyswitch with 0.5ohm resistor. Everything else is original. I used kitchen towel tube and pillows to isolate the drivers sounds.
I think this is too much overlap for a 2nd order 3 KHz crossover. Would you agree? Is something wrong?
Monitor 5 Series II
RTA 11T
RTA 11T
Comments
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Is something wrong?
Likely your testing method and tool.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Yeah, very far from scientific. But how off can the generator be in the first place? Overlap is too wide still. Are Polks accurate on the crossover frequency and rolloff rate?Monitor 5 Series II
RTA 11T -
Do they sound good to you? If so, don't worry about the results of your frequency sweep. If they don't sound good to you find another pair of speakers.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
A factor of two change in frequency is an octave.
The slope of the crossover is critical to the octave-by-octave output of the driver(s) -- particularly in an anechoic environment. In a reverberant field, I'd say all bets are off in terms of making meaningful quantitative measurements -- plus, who calibrated the "Android app"?
First order XO has a slope of 6 dB per octave. Of course, a 6 dB change in output is quite audible, but two signals, an octave apart, differing in level by 6 dB will both be clearly audible (and thus measurable). Of course, 2nd order is 12 dB per octave, but the concept is still, I'd opine, relevant.
I like @F1nut's posts above -- if you like the way it sounds, I wouldn't sweat it. If you don't, I am not sure that re-engineering the XO is an efficient way to address the "issue".
As HH Scott's famed chief engineer of old, Daniel von Recklinghausen observed:
http://hhscott.com/vonrecklinghausen.htm"If it measures good and sounds bad, -- it is bad. If it sounds good and measures bad, -- you've measured the wrong thing." -
Yeah, very far from scientific. But how off can the generator be in the first place? Overlap is too wide still. Are Polks accurate on the crossover frequency and rolloff rate?
Really??? A frequency sweep in an open room with a phone app, and you think that's in any way shape or form accurate enough to start modifying the x-over. I'd start with a better method, with better procedures and then treat the listening room.
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!
