300Hz

[pyonc]

Hi, friends,

One simple (but confusing to me) question:
Regarding crossover frequency of Ashly XR1001 in the pic below,
which one of the two markings between 2k and 4k is closest to 300hz?
Seems to me it's the second one near the 4k as it's at midpoint between them.
Please correct me if I'm wrong. Thanks.

[speakerdave]

I think if you reread your post carefully you will see that there are one or two misstatements and that it therefore makes no sense and needs to be edited.

Hi, friends,

One simple (but confusing to me) question:
Regarding crossover frequency of Ashly XR1001 in the pic below,
which one of the two markings between 2k and 4k is closest to 300hz?
Seems to me it's the second one near the 4k as it's at midpoint between them.
Please correct me if I'm wrong. Thanks.

[hjames]

Hi, friends,

One simple (but confusing to me) question:
Regarding crossover frequency of Ashly XR1001 in the pic below,
which one of the two markings between 2k and 4k is closest to 300hz?
Seems to me it's the second one near the 4k as it's at midpoint between them.
Please correct me if I'm wrong. Thanks.

When the Ashly is set in Divide by 10 mode, There is a 2K mark for 200Hz, there is a 4K mark (400Hz), and there are 2 marks in between - so figuring 3 mark for 200Hz, 300 would be just under midway between the 2 unlabelled marks, right? (assume each division is 66Hz) ...

[pyonc]

I think if you reread your post carefully you will see that there are one or two misstatements and that it therefore makes no sense and needs to be edited.

Hummmm..... Maybe that's due to my lack of audio expertise.
I was just curious about the exact 300Hz crossover point between 2k and 4k.
As you know, the yellow light (divided by 10 mode) shows 2k here indicating actually 200Hz, and 4k for 400H.
I should have identified this fact.
Hope you get my point now.

[4313B]

Crossover frequencies are marked on standard ISO 1/3 octave center frequencies with each octave calibrated. Calibration accuracy is very good, typically within 1/3 octave or better. If greater accuracy than this is necessary, measure the actual crossover frequency with an accurate oscillator/frequency counter.

[pos]

It is a log scale, so the 3000Hz position (and subsequently 300Hz in 1/10 mode) should be grossly at around 60% along the 2000Hz and 4000Hz positions on your pot.
If your markings are 1/3 octaves they are respectively 2520Hz and 3175Hz.

So... just a tiny bit before the second marking should be good enough (not sure the pot it that accurate either...).

[pyonc]

It is a log scale, so the 3000Hz position (and subsequently 300Hz in 1/10 mode) should be grossly at around 60% along the 2000Hz and 4000Hz positions on your pot.
If your markings are 1/3 octaves they are respectively 2520Hz and 3175Hz.

So... just a tiny bit before the second marking should be good enough (not sure the pot it that accurate either...).

Thanks so much! That helps me out.

[speakerdave]

Hummmm..... Maybe that's due to my lack of audio expertise.
I was just curious about the exact 300Hz crossover point between 2k and 4k.
As you know, the yellow light (divided by 10 mode) shows 2k here indicating actually 200Hz, and 4k for 400H.
I should have identified this fact.
Hope you get my point now.

Yep, my bad.

[Mr. Widget]

It is a log scale, so the 3000Hz position (and subsequently 300Hz in 1/10 mode) should be grossly at around 60% along the 2000Hz and 4000Hz positions on your pot.
If your markings are 1/3 octaves they are respectively 2520Hz and 3175Hz.

So... just a tiny bit before the second marking should be good enough (not sure the pot it that accurate either...).

I doubt they are particularly accurate, but moreover I doubt will notice much of a sonic change if you are off 100Hz one way or the other... and if you do, go with what sounds the best.


Widget

[boputnam]

I doubt they are particularly accurate...

The decals, he means. And, he's right.

Best is to go with what 4313B posted - measure the thing. Even a cheapo RTA can show you if you're in the right ballpark...

[4313B]

I doubt they are particularly accurate, but moreover I doubt will notice much of a sonic change if you are off 100Hz one way or the other... and if you do, go with what sounds the best.


Widget

OMG! Didn't you read what I posted? "Calibration accuracy is very good, typically within 1/3 octave or better."

[Mr. Widget]

OMG! Didn't you read what I posted? "Calibration accuracy is very good, typically within 1/3 octave or better."

No... missed it.

Really, 1/3 octave... I had no idea it was THAT accurate.


Widget

[4313B]

Well, we give up accuracy for convenience I suppose. When one has to build cards they come out pretty spot on.

[Ian Mackenzie]

Reminds me of that long thread about the retro converted L200 and the response problem that would not go way.

[Baron030]

If you really want to accurately set the crossover point at 300Hz. then you will need a signal generator and ideally two vu meters. You will need to feed a 300 Hz signal into the input of the Ashly and monitor the outputs with two vu meters. When the crossover frequency knob is set correctly the low pass and high pass output levels will match. This is assuming that the output levels are set the same, and the response control is set to a -6db setting then both outputs will drop by same 6db at the crossover point. Since, the vu meters are being used a comparator then their accuracy is not an issue. Working on the cheap, an old cassette deck could be used for the two vu meters and a free signal generator program could be downloaded to generate the 300Hz signal. Just hook up the cassette deck inputs to the low pass and high pass outputs and adjust the “recording levels” until they match. And then reverse the input channels to the deck and check the “recording levels” again and see if they are still matching. If the output levels match then the Ashly is accurately set to 300Hz test tone. Since, the Ashly has 24db per octave slopes, matching the outputs to within 1db equates to 1/24 of an octave change in frequency. Which makes this a pretty accurate test.
In the pass, I have used this technique with my Ashly XR so I know it will work for you.
And here is a link to a free signal generator program: http://www.natch.co.uk/downloads/SigJenny/SigJenny.html

Baron030