High quality 16ohm L-Pad

[Dr.db]

Can you recommend a L-Pad that is better sounding than the simple L-Pad´s from partsexpress for 15$ ?

I have found some serious L-Pad´s from Fostex, but they are only available in 8ohms...


Thanks a lot,
Olaf

[Chevelle]

Hallo Olaf,

I use these heavy duty l-pads from Monacor: https://www.monacor.de/produkte/comp...stbau/at-62st/

You can wire the stereo 8 ohms l-pad to a mono 16 ohms l-pad.

Gruß
Hjalmar

[pos]

If autoformers are an option for you then I can definitly recommand Bob Crites' ones.
3dB steps version: http://www.ebay.com/itm/382061369270 (the one I used for fixed attenuation, with all the taps on one side)
1.5dB steps version: http://www.ebay.com/itm/371932355023 (more suited for a variable attenuator)

[Dr.db]

Ok, so R82b and Noble RPH25 are usual lpads.

Are you aware of any other autotransformers on the market today?

[dn92]

Ok, so R82b and Noble RPH25 are usual lpads.

Are you aware of any other autotransformers on the market today?

There are nice autotransformers from Germany ;-) on eBay.
I'll try to find the link. I had the opportunity to measure two of them, and they work well. You can use them directly with Compression driver/Horn (with a power resistor in parallel to the input) like in the TAD DN2404 crossover. Distorsion only rises below 600Hz.

Note: it is there, with explanations in German special for yourself: https://www.ebay.fr/itm/Autotransfor...QAAOSwLjRa6v0N

[Dr.db]

Thanks a lot both of you!

I would like to stick with L-pads, as I have no experience with autoformers at all...
Rewire a stereo 8ohm L-pad to 16ohms seems to be an option, thank you. Are there any sonical drawbacks compared to a factory 16ohm l-pad ?

[Odd]

I have bought these;

Speaker L-Pad Volume Attenuator AT-50H 50W RMS, 16 Ohms

They seem good quality.

[pocketchange]

Keep in mind there are options that will do a better job.. pc

[pos]

Can you please elaborate?

[Dr.db]

Keep in mind there are options that will do a better job.. pc

And these would be...??

[Dr.db]

Thanks a lot for providing this very useful link!

I have to ask this silly question; do autoformers sound better than usual resistors e.g. l-pads?
Some people dislike resistors/l-pads in crossovers... But than again, JBL got rid of these in their crossovers years ago. Especially Greg Timbers wasn´t a big fan of autoformers anymore...

But I´m still wondering why they used autoformers in the past rather than using resistors. Autoformers must have been of some advantage, if not why use these more expensive autoformers when you could use cheaper resistors instead?

[Kay Pirinha]

Hi,

the main advantages are that autoformers per se don't dissipate heat and that output impedance, as seen by the driver, won't increase when turning ccw. In contary it will decrease then. But there's also a big disadvantage: Input impedance, as seen by the filter, will increase when turning ccw. Xover designers have to cope with this, as otherwise the frequency reesponce depends on the attenuator setting.

Best regards!

[dn92]

Input impedance variation is compensated by the resistor placed in parallel to the autotransformer input. With the apropriate resistor value, circuit input impedance will be the one of the resistor. For the model I provided the link I used a 8.2 ohm power resistor.

[DogBox]

Hi All,

Seems as though L-Pads in 16 ohm impedance with a '1" Shaft' are as hard to find as obsolete JBL Recones! So builders of 43xx systems, "What are you using

for your L-Pads" in your build? Are the 50W ones capable enough when it states "100W"??

If anyone can Help or direct me to their availability - I would be most grateful!! Even just to know if you're getting the 3/8" Shaft and extending it...?

What to do?

DogBox
[Steve]

[Dr.db]

@Kay Pirinha & dn92:

In laymans terms; what is the difference in sound?

@Tod:

I bet not many are aware of these, great