Speaker blending in symmetric stage setups

[physics]

Hello!

I finally have a chance to try out symmetric stage setups in a band context. However, all of the cabs will have different speakers or speaker blends due to what speakers I own and can load into the cabs, impedance concerns, and what is already loaded into the other guitar players' cabs. I wanted to ask if any of you can provide advice on how speaker blending affects the outcome of symmetric setups. My guess is it would be optimal for either two cabs per player that are different but complimentary, or for two that are as similar as possible. For the former, experience with recording and mixing different complimentary speakers would seem to imply that a fuller sound would result. However, the psycho-acoustic effect mentioned in TUT where the listener/player feels like they're in the sound because of two separated sources would seem to imply that the more difference there is between the two cabs, the less they would be sources of the "same" sound and thus the effect might be weaker.

Technical details, if it matters:
The cab pairing is going to be a 1x12 in parallel with a 4x12, and a 2x12 in parallel with a half-empty 4x12. The 2x12 has a eminence swamp thang and celestion g12h 70th anniversary, wired in parallel for 8 ohms net. The 1x12 has a 16 ohm Celestion 70-80. These two cabs aren't mine, so I am not able to control the speakers loaded in them.The speakers I own and can load into the 4x12's (which are mine) are 1x16 Ohm Vintage 30, 1x16 Ohm Marshall G12 Vintage, 4x16 Ohm Peavey Sheffield 1290. The 2x12 cab will be paired with the half-loaded 4x12, and the 1x12 with the fully-loaded 4x12, because of impedance concerns.

There aren't too many permutations possible, so worst case I can probably try all the options in a band context and see how it sounds, but I do wonder if there are any general guidelines for this beyond just separating the cabs.

Thanks for any input!

P.S. Here's a video showing and comparing the three speakers I own. It inspired the selection of the speakers I now own. https://www.youtube.com/watch?v=iciye74KoFo

[K O'Connor]

Hi Guys

Mixing speaker drivers is effective as long as you can be some distance away from the cabinets to hear the mixed output reasonably well. In a symmetric system, it is ideal that the cabinets have an identical sound particularly since each performer inevitably stands close to his own cabinet AND that of the player on the other side of the stage. if your sound is different on each side of the stage you and the opposite player will have a different impression of your sound, which could effect how he adjusts his amp or his playing.

Of course, if the players move around on stage, or are not confined to back-line positions, the possibly everyone hears the central sound which will be from all cabinets.

As I stated in another thread here, if you have open-back or detuned or half-filled cabinets, the drivers in these cabinets will reach their mechanical limits sooner than drivers in sealed cabinets. The undamped drivers have maximum efficiency and cannot handle their rated electrical power input. So, it is best to use high-wattage drivers in such cabinets to protect the driver itself, as the larger voice coil can dissipate the heat more readily than a smaller coil.

Have fun

[physics]

Ok, the semester is over now and I've had several months of experience using the basic symmetric setup both as a player and audience member, and have gotten feedback from other players. Here is a summary of all that, in case it is of use to other forum members.

The two amps with their cabs were an EVH 5150III 50W EL34 into the 2x12 and a half-loaded 4x12 with Sheffield 1290's, and a Blackstar HT Club 40 combo into it's internal speaker (Celestion Seventy-Eighty) and a 4x12 with Sheffield 1290's in an X-pattern with the V30 and Marshall Vintage speakers. The 2x12 and fully-loaded 4x12 were on one side of the stage angled towards center, and the other cabs were on the other side angled towards center.

First impressions playing through the rig for me (into the Blackstar) was "Wow, this is much closer to the sound I have in my head!" Sounded more meaty. It also seemed like the sound was less localized and directional, I could walk around the room and for the most part the sound just seemed to come from the stage as a whole, not one particular spot. Around the middle you could hear tonality cross over between the two different cabinets, but not jarringly. I could also hear myself and the other guitarist better when on stage. A few weeks in, we replaced the half-loaded 4x12 with a fully-loaded one of Carvin 100W British Series speakers from the '70s which I scored for cheap used. That improved the overall tone as the Sheffield 1290's were a bit too scooped to be heard well in the mix by themselves, and the Carvin speakers' resemblance to a V30 means it doesn't have that problem.

Other guitarists who I asked had a mostly positive response as well. One had a big grin on his face while standing right at the intersection of his two cabs' sound fields playing. He also commented on how the new setup meant he was turning down the volume on his amp. Another guitarist commented that the tone sounded meaty. The criticisms I've heard from other players when using this setup is that it is harder to distinguish themselves from the other guitar player, as they hear both themselves and the other player coming through the stack behind them. This made it trickier to know what to tweak on the amp during soundcheck after a play-through. I suspect this would be remedied with the Triangle of Tone (or was it power?) stage setup in the books, but have not had a chance to try it. I'm going to re-read things and see if there was anything mentioned along those lines.

After a couple months with this setup, there was one session where due to logistics we ran an asymmetrical setup again. My impression was that each guitar suddenly sounded localized again and more directional, and that they did not mesh together as well. With the symmetric setup they meshed so well that as an audience member it could be hard to identify the individual guitars when they played the same part because of how well they mixed. The asymmetric setup seemed harsher on the ear too, perhaps the volume was turned up louder during that session. There was also an interesting experience on a bigger stage than we normally play, meaning the normal cab angle was inadequate. We did not adjust for this, so each guitarist ended up only hearing the stack behind him and did not get any noticeable wash from the stack across the stage. The sense of being "in" the sound was lost on stage, but the symmetric setup meant we could still hear each other from the stack on our own side, at least that's my impression. Barring more cabinets for side fills, angling the cabinets more would probably be warranted next time.

Overall I'd say this was a successful experiment, and I intend to use symmetric setups as much as possible. If I can get the small issue of guitarists identifying their own "voices" ironed out, I think it'll more or less be perfect. Funny enough, the guy I bought the Carvin 4x12 from was an experienced sound man. When I told him we were trying the symmetric setup, his response was something like "that's what we've done in sound for forever!" Guess guitarists are behind the times.

Anyhow, thanks Kevin for introducing this setup in your books, and I hope the experiences I've shared are useful for others. If anyone else has experience with symmetric setups, I'd be interested in hearing about them

Thanks!

[makinrose]

Thanks for typing that up! It was very interesting to read about your experience.

[K O'Connor]

Hi Guys

That is a great report, Physics

I've been using the symmetric stage setup since 1974 to have that feeling of "being inside the sound". It saves your hearing while giving you the exact experience you are trying to achieve while cranking it up.

Yes, the instruments blend together. It forces the individuals in a band to think more about what is best for the band sound than for their individual purpose. Egos have to recede.

House PAs are usually run mono. Stereo does not really work except for people sitting close to the center line if the stage and PA speaker stacks to the left and right of the stage. With two guitars, or guitar and keyboard, where both instruments would be "featured" in a stereo mix for home listening, the live mix will tend to be far less ideal. A lot of the problem is that sound men typically over-power the space (even outdoors) to try to overcome room resonances, and environmental issues and this approach just brings on more problems. It is a huge battle to get sound men to turn down the PA. It is a similarly huge problem to b get bands to turn down their stage volume as that is the excuse every sound man uses for cranking up the PA - they want to drown out the band. Grinding a lot of axes here

The symmetric stage is the best alternative to having to go in-ear and have a clean stage with no amps. But - the band has to work like a band.

[physics]

A short update:

Currently working on adding a floor monitor/cab for each guitarist to hopefully help them better identify themselves in the mix. Concurrently, re-working our back-line to use detuned 1x12's and 2x12's loaded with EVM12S Pro-Lines. The two guys who provide the amps for the back-line were impressed with the detuned 2x12 (stock 4x12 with two speakers, in this case) loaded with EVM's, so that's encouraging. My focus right now is on fabricating a detuned 1x12 according to the plans in Kevin's DIY speaker book, as replacing a mono 4x12 with a mono detuned 1x12 is the most useful next step right now.

Kevin, in your experience does the third monitor cab on the floor in addition to the basic symmetric setup help guitarists hear themselves a bit better in the live mix compared to a symmetric setup without the floor cab? I'd guess it does since you now have a full 1/3rd of the output power pointed at your face, but I don't know enough to say for sure. Unintuitive things seem to start happening once you introduce multiple sound sources, e.g., the feeling of being "in" the sound.

[K O'Connor]

Hi Guys

As TUT2 and the DIY Speaker Cabinet books both state, having the guitar wedge in addition to the side/back-line acoustic sources gives the player the Triangle of Power, He will definitely be "inside his sound".

Every performer who experiences this never wants to go back to any other stage setup.

The player's own instrument will seem very loud and clear at the focal point of the multiple sources, yet he can easily hear the rest of the band . The experience is one of "body loudness" NOT "ear loudness", the latter being detrimental to long-term function of hearing in general, including just for this performance and for potential damage to hearing.

Also as reported in the books, the net power from the amp may in fact reduce, which becomes irrelevant with the focusing of the sound fields, and further by the use of detuned cabinets which enhance efficiency. It does not take a lot of power t have loud sound fields when you think about where those sound fields need to be.

[physics]

The player's own instrument will seem very loud and clear at the focal point of the multiple sources, yet he can easily hear the rest of the band.

Great, thanks for clarifying! I own and have read both the mentioned books, but that point was still not clear to me as evidenced in my previous post. Now that it is, I'm further motivated to finish up the guitar wedge setup. Will report back after it's complete and been used for some gigs.

Thanks!

P.S. Tangentially, now that I've experienced the Triangle of Tone, and soon the Triangle of Power, I'm wondering how I can capture that experience in a recording so that listeners in headphones or with another stereo replay setup can enjoy it too. Time to learn about surround sound I suppose.

[K O'Connor]

Hi Guys

Acoustic capture and playback are a separate thread altogether.