I promised myself to stay out of this, but on the bottom of p.2 of the brochure, Figure 3, you have a schematic of the crossover with values. You could easily rebuild that exact circuit, at least that switchable segment, with modern high quality parts. That would change nothing in relation to adjustability and tonal balance and would probably upgrade the pure SQ, just because modern parts are better. You might consult any number of speaker builder types on the subject of what to use. You could have your cake and eat it too.
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.
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’.
.................................................
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.
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- 41 posts total
I qualify flat frequency: IN THE ROOM, at the LISTENING POSITION.@elliotbnewcombjr This is where I side with @lewm ; a tone control would be more appropriate for adjusting the system to the room rather than the driver level controls (although I do understand the temptation). Proper room treatment works better and as you've stated, proper speaker placement too. Keep in mind that with only two woofers its likely that the bass won't be right, and if the bass isn't right the mids and highs won't be either. So it might be advantageous to add a couple of subs like a pair of Swarm subwoofers, placed asymmetrically in the room so as to break up standing waves that are likely to otherwise be present. |
Dave, thanks for the clarification, I yap about an issue but have often been ignorant/wrong when it get’s technical. I wouldn’t recognize an ohm if it crawled out of my boot. I always referred to these as Rheostats, Then some say Potentiometers, L-Pads, learning about changing/not changing what is shown to the crossover is specifically helpful here, thanks. .................................. BALANCE CONTROLS TO THE RESCUE E-V SIX is very illustrative of this discussion and my decision to put mine back. It is a 4 way system with a 5 ‘STEP-TYPE’ Balance Control (5 selectable/specific resistor settings) 18" Woofer, how about that! https://products.electrovoice.com/binary/E-V%20Six%20EDS.pdf Back to E-V SIX Page 2: ADJUSTMENT OF BALANCE CONTROL “precise adjustment of the system to room acoustics AND personal tastes”. Bottom of Page 2 is the wiring diagram, showing that the Balance Control alters both the Treble (upper mids) and Tweeter together, Bass and Upper Bass unchanged. Position #3 ‘Standard’ rooms; #2 and #1 are ‘CUTS’ for ‘hard/live’ rooms; # 4 and 5 are ‘BOOSTS’ for soft/dead rooms. Page 1, Figure 1, shows 5 frequency lines, each selector position and it’s resulting frequency graph. ………………………. IMO, PERSONAL TASTE should also be understood as ‘a specific listener’s hearing ability: ‘live or soft’. FMC: The Fletcher-Munson Curve shows that our hearing ability, effecting personal tastes, changes as we age. CHANGE: the rooms furnishings may/probably will change, or the speakers may be moved to another room, more dead or alive. AVERAGE is FAR FROM EVERYBODY; can be SOME, NOT MOST. FMC, like shoe size or desk/chair height, or hearing ability, is an average. I just had a hearing test. My lows are ‘un-characteristically’ still flat, mid to low highs ‘normally’ flat, upper highs decline progressively, ‘normally’. Thus I’m ‘near average’ What about you, or him or her? ……………………….. EARLY E-V systems: 2 way have 1 Balance Control; 3 way like mine, have two Balance Controls: ‘BRILLIANCE’ (only effects the Tweeter) and ‘PRESENCE’ (only effects the midrange). Quite often highly efficient horn systems. E-V literature of AT37’s and AT38’s describe them as true L-Pads, maintaining 16 or 8 ohms shown to the crossover. https://products.electrovoice.com/binary/AT37%20and%20AT38%20EDS.pdf .................................. IMO they are an asset, not a detriment. I ordered simple coil type which affects the crossover. Thanks to input from Dave and others I will return them and order true L-Pads with constant 16 ohm shown to the crossover. https://critesspeakers.com/electro-voice-crossovers.html I spoke to Bob’s son yesterday, they are still in business. ……………………………………… Using Balance Controls was easy in the MONO era, but for a STEREO PAIR, matching L to R is far from easy. I have often said, I value/need my McIntosh MODE Control to achieve matching frequency performance L to R; Volume Balance; Room Balance. Then remotely adjust volume and occasionally refine a specific track’s balance via my Remote Line Control. Now using RLC-1’s Treble control while waiting for my new L-Pads to arrive. And, MONO or STEREO, they need maintenance perhaps replacement over time. Aside from costs, I think it became hard for manufacturers to trust their use and maintenance to the general public. Hard to trust that in an given user’s space, unknown acoustics, unknown adjustments, that they would sound ’proper’ to any/everyone who might decide to buy/not buy them. ............................................. Oh yeah, the listening position diagram, 30-40 degree angle, is quite interesting. Mine is similar, but with toe-in, which I adjust for wider center for pretty decent imaging 2 listeners. Elliott |
’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 |
- 41 posts total