My experience with L pads so far is a bit of a blunt tool. When it comes down to the lower levels of adjust they just don't tend to have that much of a fine adjust on them.
Ive tried the monacour 8 ohm variant which where I can practically shut off the tweeter before I get it low enough. And the same for an 4 Ohm variant I tried recently from Willi's. I've tried with a range of drivers and configurations but they just seem to be a bit crude if I'm honest, but better than nothing.
Are there any out there which have a bit more of a refined control. I like the fact of adjusting on the fly and analoguely.
Ive tried the monacour 8 ohm variant which where I can practically shut off the tweeter before I get it low enough. And the same for an 4 Ohm variant I tried recently from Willi's. I've tried with a range of drivers and configurations but they just seem to be a bit crude if I'm honest, but better than nothing.
Are there any out there which have a bit more of a refined control. I like the fact of adjusting on the fly and analoguely.
I know what you mean, they can feel a bit crude.
Have you tried the classic technique of putting the pot between two resistors so that the pot is only a faction of the adjustment? If you are using almost all of the L-pad's attenuation, why not do most of that with fixed resistors, then use the L-pad fine tuning?
Have you tried the classic technique of putting the pot between two resistors so that the pot is only a faction of the adjustment? If you are using almost all of the L-pad's attenuation, why not do most of that with fixed resistors, then use the L-pad fine tuning?
Thanks very much for the reply
Ah ok, and yes most of the attenuation is used up and it's only really the bottom 5 or 10% I ever want to fine adjust, it would be better if the full range of the l pad was just controlling that 5-10%. So use resistors you say, I'll have to look into that. Would they be best before or after the l-pad, I suppose it wouldn't make any difference but perhaps there might be one slightly sonically either way? Any idea a good place to start resistor wise?
Ah ok, and yes most of the attenuation is used up and it's only really the bottom 5 or 10% I ever want to fine adjust, it would be better if the full range of the l pad was just controlling that 5-10%. So use resistors you say, I'll have to look into that. Would they be best before or after the l-pad, I suppose it wouldn't make any difference but perhaps there might be one slightly sonically either way? Any idea a good place to start resistor wise?
Depends on how many dBs of attenuation you require.
Assuming an 8 ohm tweeter, a series resistor of 3.9 ohm and a parallel (shunt) resistor of 8.0 ohm would give an initial 6dB of attenuation when placed in front of your variable L-Pad.
Use 5 or 10W ceramic resistors.
Thanks, I appreciate it. I will actually be using one with a 6ohm tweeter and the other in another set with 4ohm tweeters. Does this change things much?
I have been looking for information but I am getting a little confused, and shortcut or any help would be greatly appreciated, I know it might seem obvious to you and people on here but not if you are a novice DIY'er like me.
I have been looking for information but I am getting a little confused, and shortcut or any help would be greatly appreciated, I know it might seem obvious to you and people on here but not if you are a novice DIY'er like me.
See the attachment if you're unsure of how to use the resistors (Z is series, Y is parallel).
You can find a resistor calculator here
Misc >
L-pad : DIY Fever – Building my own guitars, amps and pedals
which I suggest you should match to your variable L-Pad resistance of either 8 or 4 ohm.
Attachments
Note that an L-Pad calculator will churn out the theoretical resistor values.
You can use the nearest standard resistor values as I did in post #4.
Scroll the 'Resistor Value' box in the following link to see the standard values.
Ceramic Resistors
Here's a handy stand-alone L-Pad calculator: ERSE - Crossover Calculator - L-Pad Attenuation
You can use the nearest standard resistor values as I did in post #4.
Scroll the 'Resistor Value' box in the following link to see the standard values.
Ceramic Resistors
Here's a handy stand-alone L-Pad calculator: ERSE - Crossover Calculator - L-Pad Attenuation
Some good advice and links. 
It might take a little experimenting to get this right. You'd like to end up on the middle of the L-Pad's range, not squeezed all the way to the top or bottom. So you'll need to figure out what fixed value attenuation you need.
Do you know about how much attenuation you are suing now?
It might take a little experimenting to get this right. You'd like to end up on the middle of the L-Pad's range, not squeezed all the way to the top or bottom. So you'll need to figure out what fixed value attenuation you need.Do you know about how much attenuation you are suing now?
That IS the question, and westsounds is unlikely to know unless his variable L-Pad controls have fascias with dB markings.
He mentioned his 4 ohm L-Pad came from Willys HiFi and the image in this link of the optional dB fascia may give him a clue as to how far he has the tweeter turned down. L-Pad Attenuator Mounting Fascia - Willys-Hifi Ltd
On that scale its down to around 16, and if I turn it down any less it does not fine tune effectively, it more or less switches the tweeter off. Not the best adjustment but if its full open the tweeter really is overpowering.
The 6ohm tweeter I use with a 8ohn l pad it's better because the tweeter isn't do efficient but its still low in the range for it control, similar to the 4ohm pad and tweeter.
The 6ohm tweeter I use with a 8ohn l pad it's better because the tweeter isn't do efficient but its still low in the range for it control, similar to the 4ohm pad and tweeter.
Wow, that's a lot! What is the mismatch in mid/bass vs. tweeter sensitivity?
Perhaps you should give us details of the drivers and crossover you are using in that -16dB scenario - we may be able to spot something that has gone awry.
If all else is well, it looks like you're going to need at least 6dB of extra attenuation. Happy experimenting!
Thanks for all the help again
I thought the lpads might have been enough. And they are to be fair for the most part. But when most of the adjust needed is in the lower 5% of the dial it makes fine tuning a bit hard. But it needs to be there just to get it near desired level. As you say middle of the scale would have been better.
Monacors mid basses in both sets, and just some standard crossovers crossing at 3khz
MONACOR: SPH-130
One has a set of horns which are 4ohms but loud as you can see
Peerless by Tymphany H25TG05 - 1" Horn Tweeter
The other set has 6ohm seas
H1283-06 22TAF/G
The control on the seas unit is slightly better but as you can see it not so sensitive. But again the required level and control is near the lower part of the l pads operation.
I thought the lpads might have been enough. And they are to be fair for the most part. But when most of the adjust needed is in the lower 5% of the dial it makes fine tuning a bit hard. But it needs to be there just to get it near desired level. As you say middle of the scale would have been better.
Monacors mid basses in both sets, and just some standard crossovers crossing at 3khz
MONACOR: SPH-130
One has a set of horns which are 4ohms but loud as you can see
Peerless by Tymphany H25TG05 - 1" Horn Tweeter
The other set has 6ohm seas
H1283-06 22TAF/G
The control on the seas unit is slightly better but as you can see it not so sensitive. But again the required level and control is near the lower part of the l pads operation.
Monacor 8 ohm mid/bass: 89dB/W/m.
Peerless 4 ohm horn tweeter: 98.1dB/2.83V/m.
SEAS 6 ohm metal dome tweeter: 92dB/2.83V/m
The sensitivities are not directly comparable, but the SEAS shouldn't be hard to control on your variable L-Pad.
I suspect we may need to look at your 'standard' crossover design.
P.S. I assume you have wired the L-Pad correctly?
Peerless 4 ohm horn tweeter: 98.1dB/2.83V/m.
SEAS 6 ohm metal dome tweeter: 92dB/2.83V/m
The sensitivities are not directly comparable, but the SEAS shouldn't be hard to control on your variable L-Pad.
I suspect we may need to look at your 'standard' crossover design.
P.S. I assume you have wired the L-Pad correctly?
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the seas isnt as bad I admit, I could live with it as is, the horn is really the issue however I have got it fairly near, perhaps I should just try a bit of experimenting with the resistors on the horn so it I can get it in a better range on the dial.
