Build a plate reverb

[cyrusparty]

I remember a few years back there was an article in Tape-Op about building a plate reverb. Seemed pretty interesting and might be worth looking up. All my old issues are packed up in storage, otherwise i'd get you the date. I don't think it was the most sophisticated design and seemed like a somewhat easy build. From what I remember, the hardest part seemed to be in actual plate selection and finding a place that stocks more than a few suitable plates. Good luck! Keep us posted!

[J M Fahey]

To all of you raising one eyebrow in scepticism.

C'mon über, nobody said that.
In fact, most of us are very interested in this, just we don't have much real experience on them (well, some experience as users), except JRFrondelli.(why doesn't this surprise me? )
Go on, share what you do and we'll try to help along the path.
Best wishes.

[NorCalTuna]

I think this is a great thread, anything thats been invented can be reinvented! A friend of mine is a comp guru and attached a bunch of these Clark Synthesis TST209 Tactile Transducer to his piano and fed it all sorts of things. That said, that's a great way to go for a plate reverb, I suspect. Look at the force that thing cranks out- but i'm wondering if it's useful f range is more related to the "audible" or "tactile" factor. PE has tons of those things...

The frames a no-brainer. Damping it is a great idea, and again pretty reasonable to implement. So, how about the material for the plate, the spring tension and the output transducers?

The speed of sound in steel is 3000-6000m/s iirc, but typically 5-6k, so the composition may have a lot to do with the overall fs of the thing, in conjunction with the springs, which I think may also serve to tune the SHO the plate forms, they may even need to be somewhat adjustable. I'm thinking about it in terms of "preload" on a race car shock- the more preload, the more force it takes to load the spring. I don't know if the analogy is valid. It's thin too, that is known. I have lots of scrap steel places in my area, I wonder if you could literally go find a "good sounding" piece by ear. At least a "live" one, i'd think. With those modern transducers, I bet you could use a thicker plate than one suspects for higher noise rejection, it's own mass would damp outside vibrations though needing more force to resonate it. Everything resonates with enough force! The EMT140 was driven by a V54 amp, which if the slutz are correct, has a 12ay7.

The output transducer also seems like it's easy to tinker with and could be all sorts of things, or multiple ones that could be switched for different sounds. One web site has a telephone unit!

[km6xz]

Plates that people remember on records were not the sort of thing that would be easily duplicated by experiment. But go for it, have fun.
My studio had a large room with 6 of the EMT plates suspended from a frame tied into the ceiling and 1 large motor drive(for remotely controlling the position of the exciter speaker inside the very irregularly shaped room with no parallel surfaces...13 of them) echo chamber. Each was connected to a central patch panel that could route signals to and from each of the 3 studios. They were used on a lot of well known records and pretty much ruled the day....until the first EMT and early Lexicon digital reverbs started showing up. The best thing about the digitals was resetability which the plates were not great for. The remotes for the plates and the echo chamber were mounted into each console. A producer could leave a project for a week and come back and resume with similar sounds. That was also the reason the first practical piano replacement (Kurz. 250) was a hit, and the curse of very well paid piano tuners who were getting paid daily for any session needing to continuity from hour to hour from the grand pianos.
It was not easy to maintain the plates, they were under great tension and any mis-adjustment would break the plate mounting clips. Temperature and humidity changes change their sound, if tube series, they should be left on all the time for that reason. After the digitals came onto the scene, their reputation for high cost allowed studios to charge extra as internal rentals for another $100-200 a day. A lot of the gear purchased by major studios were not due to sound quality but for the buzz they had that allowed higher charges. The investment was usually considered long term, a good console or deck or effects unit costing about the same a 3 bedroom house had to have a long income producing life. Now, a studio could not keep up with the pace of new gear and ever hope to earn its cost. But that was back when labels had reasonable production budgets so any of the 8-12 studios, that at any given time, were producing the vast majority of income for the recording industry could actually make a good deal of money. There were hundreds of decent demo studios and a dozen or so decent album studios and most made a profit.
For all the tech specs of digital, a good echo chamber is still my favorite. The classic chambers were under the Capital Records building which had eq'ed telco lines running to the major studios in the area and scoring stages. They charged by the project and hour so few So-Cal studios that could have afforded the space and environmental conditioning needed for echo chambers did bother with their own.
The producers later picked up on the fact that studios could get a good price per day for rentals of studio owned specialty gear like the then new $25k digital reverbs while the labels and producers were hammering on them for price of rooms, a few started packing modules into wooden boxes with handles, and insisted that they be rented from the producer on a daily charge. Val Gray was probably the first one I saw who insisted on $200 for his vocal rig, a wooden box set on the console that had a preamp and a eq, the size of a lunch box. That started a trend and the hobbyists picked up on it thinking that it was needed for pro -type sound. Suddenly everyone was using outboard preamps and eq's without ever really knowing whether it was better or not for the delivered product. I doubt any of that outboard gear ever created even $1 more in sales of records.

[Enzo]

Back in my hippie days, wandering about town in the night exploring experiences and sensations... ahem...

There was a parking ramp on the college campus. Typical three story cement ramp. To dress it up a little they had mounted long vertical strips of what looked to me like steel roofing panels. Flat steel sheets a couple feet wide with lengthwise ribs creased into it every few inches. Sort of a steel corduroy. Looked like the stuff they roof pole barns with.

I could put my ear by it, and rap on it with a coin, a small rock, whatever, something hard. You could hear the shockwave travelling away down the length of it and reflecting back. A sort of "tcheeuuww" sound - not a bad sci-fi ray blaster sound.

And of course a large sheet of Masonite or something will make a fine woop-woop sound if you flex it. A large sheet of most anything will make some interesting noises. And a good mechanical conductor like metal has potential.

Point being that while trying to duplicate an official plate reverb is fine, but you might coax some interesting reverb sound out of something common like a piece of roofing.

And as a kid I was learning electronics by involving myself in short wave radio. SO I was always stringing antenna wires all over the place. A 40 foot piece of relatively taut wire when plucked will send a sound wave running the length and reflecting back. Pretty much like a rever - imagine curling my wire up into a spring - voila, reverb. And instead of whacking it with a stone, it should be simple enough to drive it with audio.

[jrfrond]

Citing the last two posts: Stan (km6xz) and Doug (Enzo) are of a decidely more, er.... vintage breed. What this means is that we grew up and learned this business in an era when sounds were MADE, not recalled. As a result, we all learned how to manipulate cranky rack gear and electro-mechanical reverb units and whatever else we could get our hands on to create a particular sound, rather than recalling factory presets. When the digital stuff finaly made it's debut, we knew what parameters required editing to make them sound more realistic, because essentially, we LIVED those parameters. But you had to MAKE it happen. Stuff like Pre-Delay, EQ, Sidechaining, Gating et al was all created by the engineer with outboard gear and a patchbay. It afforded us a better perspective when the digital gear came on board, much the same way film photographers and paste-up artists would know what to do later with applications like Photoshop and Quark, because all of those parameters were referenced verbatim in the software versions. Referring back to reverbs, we KNEW what live chambers, springs, plates etc. sounded like and where they were best used because they were all discrete items that we dealt with, not just a patch in a box.

Going back to plates: Doug is correct about plate materials. They aren't written in stone. In fact, EMT later marketed the more compact and very different-sounding (darker) EMT240 Gold-Foil unit, which later yielded to their first digital unit, the EMT250. The gold-foil unit wasn't terribly popular as a REPLACEMENT for the EMT140, which was their intention, but was yet ANOTHER voice in the arsenal.

[Gtr_tech]

I googled and found numerous links:

YouTube - ‪DIY Plate Reverb - Build your own $10 plate reverb‬‏

how to make a plate reverb

Recording: How To Build Your Own Plate Reverb: A Concise Step By Step Process - Pro Sound Web

That first link......thin aluminum as the plate? Just as I was clicking the link I was thinking how shitty that would sound. Sure enough.....dark and dead sounding. He needs to use steel (or something harder) to transmit highs.

[km6xz]

If my memory serves me right, the EMT 144 was first by 4 years. The 250 was the one that we all HAD to have, the price of 2 corvettes or a small rural home.
We got a 250 in 1976, possibly the first on the west Coast. It was the standard that all that came afterwards was measured against. Specs were not great but it sure sounded great...12 bit conversion!
We got a couple 244s later, a cheaper rack mount version that only had one program...reverb and it sound good also. Skipped the 251 when it came out but got one used years later that was broken and repaired it by reverse engineering parts of the main digital board...about 100 hours of time spent on that.
My appreciation for digital increased a lot when the Quantec QRS came out, ONLY $12,000 but had very nice modelling of real room sounds. Still love 'em. The Lexicon 224 was a big hit also. It had a lot of flexibility, and the echo chamber and plates started getting a lot less use.
People learned that I repaired our 251 and Quantec so there was some interest in getting their repaired. I collected old chips and built up some test jigs to be able to test individual boards. I almost cornered the market on old 1kb memory that could only be found fast enough in military or space surplus outlets.
The Quantec is really bizarre inside, all the precision data and syncing between the 10 pc boards was on one line, the master clock line...I/O, Data, control...everything multiplexed on 1 clock line. ANY timing anomaly as in old slower chips, would crash the whole thing...whew...but when used in service the things were amazing.
Fun stuff...But as John said, there was a completely different sort of inventiveness that went into every session, using basic gear, to create remarkably varied results in sounds, in many genres, with the same basic gear. I do not hear that inventiveness much now, where there is a different less organic approach to "assembling a song". With so much technical performance of the new digital gear, I am taken aback by how uninteresting most recordings are now. There is a new acceptance of mediocrity that is disappointing. The same goes for musicianship. By far the most guitarists are not worth listening to, not enough practice and fundamentals and too much reliance on trick sounds and patches, but musically and emotionally sterile. In the past there were a lot of garage bands also but the difference was that never got close to a recording studio so they either got good eventually or faded away before anyone had to hear them. So much concern over the nuances of tubes and brands of wire and no concern over lousing playing of lousy songs.

[jrfrond]

.....there was a completely different sort of inventiveness that went into every session, using basic gear, to create remarkably varied results in sounds, in many genres, with the same basic gear. I do not hear that inventiveness much now, where there is a different less organic approach to "assembling a song". With so much technical performance of the new digital gear, I am taken aback by how uninteresting most recordings are now. There is a new acceptance of mediocrity that is disappointing. The same goes for musicianship. By far the most guitarists are not worth listening to, not enough practice and fundamentals and too much reliance on trick sounds and patches, but musically and emotionally sterile. In the past there were a lot of garage bands also but the difference was that never got close to a recording studio so they either got good eventually or faded away before anyone had to hear them. So much concern over the nuances of tubes and brands of wire and no concern over lousing playing of lousy songs.

You pretty much nailed it right there Stan.

When you think about it, EVERYTHING was a variable, right down to what tape formulation and speed you chose, how you biased the machines, whether or not you used noise reduction, and how hard you hit the tape. The whole analog system was malleable. You could mold it at will to produce exactly what you needed, or to create something totally new. However, you DID need to know how it all worked, signal chain placement and some good old audio electronics theory, plus things like mic placement and selection, etc. Not surprisingly, there's a whole lot of technical knowledge that goes unknown by many so-called modern-day engineers and producers. It's more like assembling a meal at McDonalds as opposed to practicing culinary art.

[überfuzz]

With a degree in Engineering Physics I'm taught to calculate everything. Sure enough, al you say about the plate seems to... compute. When I calculated the frequency it boiled down to:
S = tension in the plate
d = density
W = pi/2 * (5*S/d)^0.5 ; I did cut some corners while calculating, no induced force, no thickness suggested, etc, but you'll get the point. my calculations


So what does this tell us? A tensioned stiff metal is a good preference. As I don't know much about metallurgy I'd have to ask around. However, the plate I'm getting should be thin and hard, preferably with high density. I have to strengthen the corners so they can bear some tension. I'll tension the plate with 4 turn-buckles.

I'll keep you updated.

[km6xz]

John, we are sounding like old fogies with the " this young whippersnappers just don't do it like we did" but it really was different in concept and the idea of a song.

Almost daily someone ass specifics about how to get the sound on a particular cut "what mic did you use, and which position" or effects...brands and models because attempts to recreate it were not working. The assumption is that if you have the same gadgets, and place the mics in the same standard named positions, the same formula will naturally produce the same results. Ah...no, that is backwards. We used gear because it was what we had and when it did not do something we needed done we introduced novel solutions to the problem at hand, a session was one big problem solving or avoidance exercise. The answer to they why something was used, was often because it masked a particular unwanted element that only existed in that exact situation in time and space. Why a mic is selected is often not for the optimum capture but to mask the badness of some trait in a voice. Typcially a "safe" middle ground would be used in some basic tracks and listened to. Then with a better understanding of the problems revealed, the tool kit of tricks, innovation, hacks went into effect. How else do some of the recordings sound better than the technical limits of the gear? Because listener experience and tricking the brain into not hearing the problems that might detract from the perception of the aural image intended. A lot of those records sound better than they should if taken a the results of the whole of equipment performance because that was the intend to camouflage and misdirect the listener's brain into not hearing the distractions. Number 1 goal at all times: perception of the song. Not a perfect capture. A perfect capture would often be the last thing we wanted because of the traits of the voices or playing, technical limits, noise floor etc.
The differences between the demo studios and the major album studios was using the demo studios had a more workmanlike process, a standard useful drum setup or more cookie cutter process of recording. Technically there was not that much difference in gear. A MCI was not that much different than our more refined Studers and Ampex ATRs or older MM1200's nor were the demo studio's board's that much lower in quality than the APIs, Trident, Neve etc. The difference in the major album studio was attention to detail, little things that seem to everyone else as insignificant such as the way cables were run across the studio floor or meticulous storage of tape or 4 times a day tuning the piano, or full alignment of the deck every few hours. You can't hear the difference in one track soloed but when combining 24 or 48 analog tracks those little inaudible differences add up to give a difference aural image. The other major reason demo studios and the few top album studios differed so much in output was the accumulated expertise. A major album studio had real expertise available in all aspects of the project...the seconds could have been the first engineers in any other type of studio, top flight maintenance engineers, enough engineering chops and staff talent to pull anything needed out of the hat. THAT is what is mostly lacking in the new one man operations, no one person can be such an expert in recording, producing, management, tech work etc. The home studios and small computer based project studios that do a lot of the commercial recordings now are too small to have a brain trust on staff.
Song writing has changed a lot also. Songs more often than not start with a beat box and is build up with loops and patches until it is interesting, and only at the later stages do lyrics come into existence. Unfortunately it often sounds like it is pieced together rather than developed as a whole concept. Because it is so cheap and easy to record, songs are usually recorded well before the song is fully worked out, more matured into playability or singability. After someone had taken a song on the road and sang it 200 times, it matures, becomes more believable and authentic as the singer evolves their phrasing, performance etc. The song becomes almost a tangible object with recognizable traits and images. That makes a song easier to record, we now where it is going when we start, we already know we like it and feel a strong motive to bring to light.
It all boils down to everything EXCEPT the equipment was important in creating a compelling listener experience. A good team, with a good song, would have been just as successful in the audiences view if they did it in any studio, big or small, well equipped or not. But those good teams were rare, but they rules the charts for decades, a different cast, for sure but the same concept of team.

[überfuzz]

Hmm, right now it seems as if the plate itself will be the trickiest part. Not molesting it with my power drill... Ehh... Seriously, It seems to be hard getting the plate. Right now I don't have the slightest where to get it.