L-Pads. Speakers Awful Without Them, New Ones Ordered


I removed the L-Pads, the tweeters are way too bright, screechy above mids. Disturbing. Played my best source: R2R, Sgt. Peppers. Normally magnificent. Unlistenable!

Using my Chase Remote Control to cut Treble temporarily, until new L-Pads arrive.

I ordered these 16 ohm pads:

https://www.ebay.com/itm/153892668925

mine don’t have the issues he discusses, my insulation is modern, crossovers are tar filled metal cans, not much heat in 6.3 cu ft; these and originals were large ceramic body.

Will put the tweeter ’Brilliance’ ones in first, listen. Then add ’Presence’, listen, decide: leave in, or out. IN more than likely. They (orig and 1 set of replacements) have been IN for 62 years.

My original bronze ones came from original Fisher console, they were a custom version, still labeled ’Brilliance’ and ’Presence’.
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Many of these old Electro-Voice designs had L-Pads (16 ohm used AT37 Attenuators; 8 ohm used AT38). 2 way have one. 3 way designs have two: ’Brilliance’ and ’Presence’.

You can balance the drivers to each other, and to each space, and as you age, ability to hear highs diminishes, you can creep the tweeters up speck by speck. Imbalance due to irregular spacing: adjust each individually

I’m not going to measure and install a fixed resistor, I want future adjustability.

’L-Pads: Terrible Idea’. Bullshite, everyone who ever heard them loves them!

And, let’s not forget, the originals, with L-Pads, first one mono speaker, later two for stereo, are the designs that made these companies successful.






elliottbnewcombjr
’L-Pads: Terrible Idea’. Bullshite, everyone who ever heard them loves them!

While I am a big fan of appropriate use of tone controls and EQ in general speaker L-pads are not one of my favorite things. The main issue with them is reliability. Wipers and high power don’t work very well and can degrade rather quickly IMHO. A line level tone control, with voltages ~ 1 V or less, and milliamps of current is much more reliable.

Suit yourself, but these devices are just not that reliable and often degrade over time.

Best,

Erik


lewm,

Yes, it occurred to me I could make a 5 ’step-type’ resistor type as you would surely prefer. Would have to, but could find the ’exact’ resistors for my specific driver’s (not the SIX). Figure out the mechanics for changing individual selection. It would not be inexpensive.

Or, stick with a simple progressive level of adjustment via proper high quality L-Pads.

After 46 years designing Corporate Offices, each plan, decision, budget, schedule, light fixture (I designed my own frequently), hvac system decision (I hired my own engineers), each item selection the ’best’ choice I can find/make for clients:

when I retired I decided to leave the constant search for perfection behind.

These things worked well then and now, you know I like vintage, not to mention I have two 1-3/4" diameter holes in each speaker’s rosewood back panel. High in the rear corners where I can reach them without moving the speaker out of position.

I will transfer what I buy from Crites into my original face plates. Fisher’s Recessed Cup and push on knob, both Bronze. They fit these 4 holes and recess into the 3/4" back panel. I will position them, not like EV AT37’s were, 0 to 9, but as Fisher did: up is center attenuation, then up or down from there. These drivers/this 3 way system was originally designed to perform ’normally’ in the center of the attenuation range. That’s why they are so screechy without attenuation.
Of course if I really wanted to be a scoundrel I'd troll with something like :

Using a transformer with multiple taps is the only proper way to implement variable driver levels.


But I'm not a scoundrel.  :-)

Erik
In the course of this discussion, I came to appreciate that you are most interested in preserving the original or vintage sound of your speakers. Which is surely a worthy goal. That is why I suggested you can keep the frequency divider network as it is, and yet improve it by upgrading the parts inside. When you put an aftermarket L pad in there, there is a risk you will come up with a sound that is quite different. I look forward to your reporting the results of installing a new L Pad. By the way, I don’t see why you say my idea is expensive. You need to buy five high-quality resistors per speaker  and if you want to get really crazy, you could also replace the associated capacitors but there is no need to spend huge dollars on those parts and the rest is DIY. There is a bUsiness, Madisound, that specializes in speaker parts. Anyway, carry on.
Erik,

Scoundrel Thou Art.

The other thread was about my 16 ohm speakers, my amp having 16 ohm taps, and sadly it’s bias adjustments only with the bottom off.

Maintenance, I found the wires of the original L-Pads fried when I blew the tweeters blasting In-A-Gadda-Da-Vida. Replaced them, 16 ohm L-Pads were easy to find those days.

lewm made me remove them. As long as they are out, sounded terrible, thought I would find better ones to re-insert. 16 ohm no longer easy to find. Hooray for Crites, they seem to be high quality,

Lewm,

Did I forget the punch line: I’m lazy.

Seriously, I try to think long: For me, I prefer the ability to tame the tweeters now, and easily achieve progressive boost, speck by speck, as my ability to hear highs diminishes. I die, Donna, who loves them, might move in with her twin sister, then give them to my son Chris. Who knows who and where they will be in the future. That’s the beauty of Balance Controls of any kind.
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Making new speaker cables has led to a full ’long’ look at these speakers, what should I overhaul? Spares?. To keep going for the next generation, people who know nothing except they sound great.

Woofers: just replaced one 15W with dried out paper cone (near the hot-air wall vent) with my re-coned spare; bought a recently re-coned 15W; bought a cone kit for my dried out one, will have a spare pair.

Horn Mid: Original, 62 years old still sounding great, 1 spare downstairs

Horn Tweeters: T350’s, 16 ohms at least 50 years old, pair of spares downstairs. (not sure if 16 or 8 ohm versions).

And, a spare pair of the original tweeters from 1956: smaller T35b’s, 16 ohm (early smaller magnet than later T35’s) They were re-coned by E-V many years ago after Iron Butterfly blew them. That’s when I put the T350’s in (and cut their +3db higher efficiency/output with you know what).

How can the diaphragms of these 62 year old horns still sound great? E-V said: "virtually indestructible phenolic-impregnated linen".

I asked Bob Crite’s son, he said, yes, if working leave them alone, they can last forever.

Crossover: Original x336, tar filled can. Crites says leave them alone. I can easily revisit that later.

Given that I am leaving the crossover, horns, re-coned woofers, I don’t think lewm or many of you would qualify any part of these ’best’, and in context, I think real 16 ohm L-Pads fit right in with the other decisions.

yap yap yap, even I’m getting tired of this