idiots guide to reading diagrams
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SBLXover
You will not be aided by changes in crcuit diagrams that have probably resulted from convenience on the www.
Resistors were aways just zigzag lines - potentiometers were zigzag lines with arrows struck through. In fact anything adjustable just had an arrow through, although it it was used as a divider, it had an external arrow and connection of the arrow.
Inductors were always coils with very obvious loops in the symbol.
Decimal points also always used to be used but in cap's, the decimal fraction symbol is now used - u and p mostly, instead. In resistors, R is now used instead of the decimal point.
Polar caps were always a symbol with heavy and light parallel lines but now polar caps usually get a + on the positive connection.
Resistors were aways just zigzag lines - potentiometers were zigzag lines with arrows struck through. In fact anything adjustable just had an arrow through, although it it was used as a divider, it had an external arrow and connection of the arrow.
Inductors were always coils with very obvious loops in the symbol.
Decimal points also always used to be used but in cap's, the decimal fraction symbol is now used - u and p mostly, instead. In resistors, R is now used instead of the decimal point.
Polar caps were always a symbol with heavy and light parallel lines but now polar caps usually get a + on the positive connection.
say it as it is
pfm Member
also been suggested to try and tame the upper frequencies on my Intros to try and fit a resistor in the tweeters to lower their output slightly.
what values should I try, I get it will be trial and error and listen and see.
I think the issue is the internal XO was meant for the Vifa tweeter, seems most if not all that had the scanspeak had external more complex XO for both HF and LF. So I am stuck with the internal XO and seems retrofitted scanspeak tweeters hence the imbalance.
IMG_20210531_155430823[1]
IMG_20210531_155323233[1]
IMG_20210531_155409191[1]
IMG_20210531_155329156[1]
this is what fitted just now I don't have a set of external ones ie SBL ones to compare at the moment. Can anyone advise what size resistors to try to reduce the HF slightly?
what values should I try, I get it will be trial and error and listen and see.
I think the issue is the internal XO was meant for the Vifa tweeter, seems most if not all that had the scanspeak had external more complex XO for both HF and LF. So I am stuck with the internal XO and seems retrofitted scanspeak tweeters hence the imbalance.
IMG_20210531_155430823[1]IMG_20210531_155323233[1] IMG_20210531_155409191[1] IMG_20210531_155329156[1]this is what fitted just now I don't have a set of external ones ie SBL ones to compare at the moment. Can anyone advise what size resistors to try to reduce the HF slightly?
say it as it is
pfm Member
Named are Mr Henry, so Henrys
say it as it is
pfm Member
IN the tweeter? Perhaps inline - if so, you really need non-inductive resistors and a few ohms would be all that you need. They'd really need to be a couple of watt as well, not eighth watt as normal.
say it as it is
pfm Member
yes suggested I try that inline of the tweeters to try and balance it out just now the HF output is too high compared to the LF the bass gets lost use enough volume to get bass and treble is way too loud to listen
mansr
Objectionist
The European standard symbol for resistors is a rectangle, as seen in the OP's image.
Straight and curved lines is another common convention.
say it as it is
pfm Member
ok so start with non inductive 2w say 2ohm and work up until I hear a difference?
The symbol was a zigzag line, exactly as I said. There will be millions upon millions of circuit diagrams out there using a zigzag.
Unless you have some, they will not be cheap. They are usually wirewound using a looped wire, making them non-inductive.
say it as it is
pfm Member
ok so looking for wire wound 2w 2ohm then?
mansr
Objectionist
Yes, zigzag is the American standard symbol for a resistor. British usage is likely all over the place.
James
Lord of the Erg\o/s
There are two places where a resistor can be fitted to the tweeter circuit; between the input and filter, and between the filter and the tweeter. Fitting it between the filter and tweeter will not only change the level; the shape of its response (transfer function) will change as well. That is because the resistor adds to the voice-coil impedance, which in turn reacts with the filter to enable it to do its job. The correct way to avoid this is to use an L-Pad, which requires the correct value pairs to be calculated for the desired attenuation - without changing the shape of the response.
The easy way to reduce tweeter output is to insert the resistor between the input and filter. Following the diagram below:
I'd start with a 2R 10W resistor in front of C1 (but not before the woofer). C2 and R1 seems to be a zobel circuit; leave that alone.
The easy way to reduce tweeter output is to insert the resistor between the input and filter. Following the diagram below:
I'd start with a 2R 10W resistor in front of C1 (but not before the woofer). C2 and R1 seems to be a zobel circuit; leave that alone.
https://en.wikipedia.org/wiki/Henry_(unit)#Use
"The International System of Units (SI) specifies to write the symbol of a unit named for a person with an initial capital letter, while the name is not capitalized in sentence text, except when any word in that position would be capitalized, such as at the beginning of a sentence or in material using title case.
The United States National Institute of Standards and Technology recommends users writing in English to use the plural as henries.[4]:31"
But there are probably different standards or even names used in different parts of the world, similar to differing opinions wrt which side of the road to drive on, and whether to call something a valve or a tube.
suzywong
Wot, no electrons?
I've seen, and used, both in my career. Sometimes capitalised, sometimes not.
Similarly, for resistors, I've seen and used zigzags and rectangles (to this day, I still zigzag); for electrolytics, bold and non-bold lines, filled and unfilled rectangles, straight and curved lines, and two parallel lines with a plus sign (I still use this).
Logic gates as circles, squares, and curvy "Texas Instr." style - my favourite, as I salvaged my TI 54/74 series books (from the '80s) when I retired - my Fairchild 4000 series CMOS book disappeared many years ago.......
Also inches and millimetres.
A lot changes over the course of fifty years!
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