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T h e L- P a d s are in !!!!


Born2RockU

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Yes....the L-Pads , installed on my K-Horn AK-3 crossovers, have done exactly what was needed.

As many of you may know, I have constantly been complaining about the squawker being too loud on my Heritage equipment . AND, I didn't want to invest $500 into custom crossovers, so ERIK Mandaville came up an easy solution........ L- P a d s !

( They cost a whopping $12.50 each at Parts Express.com )

Let me vouch for this L-Pad technique...if you have the slightest hint of mid-range dominance coming from your K-Horns, then this is the easiest solution.

*** With just a twist of the knob the problem was solved !!! ***

Thank you ERIK.....you are da man !

Here is the link to ERIK Mandavilles comments after hearing my system, yesterday.

** Don't forget to add the " }" at the end of this link.**

http://forums.klipsch.com/idealbb/view.asp?topicID=58071&pageNo=1&num=&sessionID={F6CCCBAB-7924-4BFC-833D-E10CCBA2AA00 }

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Hey, Jim:

The way I did this was to take the L-pad body apart, drill a hole in the cent of the metal housing, did a little filing of the shaft, screwed the housing right onto the board in place of the autoformer, installed the actual L-pad back into the housing, and made the connections.

The cable used on those networks to the drivers it pretty stout monster cable, which I think might improved with just a 16 AWG cable (I use silver over copper Teflon insulation for mine, which does very well).

I hope things are going well for ya!

Erik

PS: Audio is too serious to use a word like 'fun' to describe it! 2.gif

NOT! We had a blast yesterday.

Erik

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Eric said:

The way I did this was to take the L-pad body apart, drill a hole in the cent of the metal housing, did a little filing of the shaft, screwed the housing right onto the board in place of the autoformer, installed the actual L-pad back into the housing, and made the connections.

--------------------

Hey Eric

I'm curious now about this crossover configuration your running now. In your orginal post on the L-pad install you mention a AA-to-A network. So exactly how is your network configured and am I understanding correctly that you have actually replaced the autoformer with the L-pad.

For some reason I thought you had installed the L-pad after the autoformer which wouldn't affect the crossover point very much if you used a 16ohm L-pad but would allow you to attenuate the squawker.

What value capacitor do you have in the squawker circuit?

Looks to me like it would take a change in the capacitor value to maintain close to the same crossover point for the squawker with the autoformer not in the circuit and dependent on the L-pad value.

Anyway I'm glad you like this change but I'm trying to understand just what all has changed with this modification which if I'm understanding this right looks like the squawker's crossover point has changed as well as you being able to adjust the squawker level.

mike1.gif

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What's up Craig!? Glad those are working out for you!

Mike: The L-pad functions as a voltage divider AFTER the crossover, which works fine in this application. Some like L-pads, and some don't, but I have found this to work just fine. The cap value remains the same, and the attenuator is installed in place of the autoformer.

You're right. I'm using an AA converted to A networks with L-pads in my Klipschorns right now, and they sound fantastic.

Erik

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Doing great ERIK. Thanx for askin'.

Another "empty sky" in Houston. Don't ya just love it when we get weather like this.

Me and Marjan have been finishing constructing the Cloth Grill for the LaScala that you dropped off yesterday. (thank you so much) It looks incredible w/ the grill !

Thank You again for the BLAST we had yesterday, ....let's do it again soon !

~Peace.

***The L-Pad has taken the K-Horns to another dimension. Better highs and better lows...all the way around.***

~Y o u a r e da man !!!

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An L-pad will burn out if you continously apply high voltages and use the maximum attenuation. There is loss in the form of heat, and after a while they become scratchy. An autoformer does not have this problem.

There was a dope from hope that mentioned the usage of l-pads, and PWK said that most certainly the consumer would end up altering the frequency response for the worse. He was on the idea that we should treat the room, rather than alter the response of the speaker.

If it works for you, then by all means do it. With low wattages, you should never have a problem.

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Mike:

"If it works for you, then by all means do it. With low wattages, you should never have a problem."

Thanks for your response. I have used many different L-pads and wire-wound potentiometers, and they are not all created equal or in the same way. A very rubust device was chosen for this application, and it will probably never see the kind of voltage for which it was designed. The resistive elements are 'nested' within a cast ceramic body, very much like a power resistor, and the wiper and all other mechanical aspect of the control are very heavy duty. They will maintain an even impedance load for the amplifier regardless of the position of the wiper. The person for whom I did the work wanted a means of more finely controlling the output of the midrange, and this is what is commonly used. Another way to do it would be to use a fixed L-pad rather than variable, or by using several values of series resistance, controlled by a multi-positioin switch.

What PWK has used is fine and good, but he is not the only speaker and/or crossover designer in existence. There are MANY companies that use L-pads in driver matching applications, which is why it's possible to buy them. I have speakers I built in the early 1990s that use L-pads, and they all work fine.

If problems arise, which I don't think will be the case, they can be dealt with and fixed.

Erik

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So, am I to understand that that you've done away with the autoformer completely? This resistor device takes the place of the auto-former? Or works in addition to it? It basically drains off power to ground rather than being a resistive element in series? Is that right?

Are you going to be able to come up with that part number? :)

Tom

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3dzapper,

I have the reciept in front of me.

Parts Express 1-800-338-0521 8am-8pm EST

Part # 260-261 L-Pad 16ohm 100w Mono 3/8" SHAFT

Two L-Pads will cost you exactly $18.41 w/ UPS Ground shipping

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