Solo Acoustic Sound: Amp vs. PA

[Ed Goist]

For those of you who perform solo with acoustic instrumentation and two microphones (vox & instrument), what is your preferred amplification for small venues, a two channel acoustic amp or a small personal PA system? Why?

[foldedpath]

I don't perform solo, but the current band is a duo (mandolin + guitar) which is close. I don't think I'd change what we're doing if I was a solo act. So here goes:

I've used both acoustic amps and compact PA systems over the years. I currently own two very nice acoustic amps: a Rivera Sedona 55 combo and an AER Alpha. The Sedona is all-tube with a wonderful sound, and it doubles as an electric guitar/mandolin amp. But it's a heavy sucker, and I'm not getting any younger, so it doesn't leave the house anymore. The Alpha is very compact, very lightweight; the perfect amp for the smallest gigs. Neither of these amps have two mic inputs so this won't directly answer Ed's question, but it will help establish where I'm coming from, with the amp vs. compact PA question.

I don't gig with these amps anymore. For even the smallest duo gigs, I'll take a powered PA speaker (QSC K10) and my smallest mixer (Allen & Heath ZED-10FX). The K10 bi-amped PA speaker sounds better than the acoustic amps I've heard (other than the Sedona which is sort of a special case), and the waveguide has better horizontal dispersion for room coverage than a typical acoustic amp. Also, while I've sometimes just set the K10 on a nearby chair for minimalist gigs, I have the option to carry a speaker stand and get it way up in the air, which also covers the room better than a typical acoustic amp on the floor. This is one of the main advantages of a conventional PA over even a "tower" system like the Bose or Fishman Solo -- you can get the sound dispersion up over the heads of people in the front row, to cover the room better and avoid blasting the people right in front.

The little ZED-10FX mixer has better EQ than many acoustic amps with its sweep midrange, and it can handle all the inputs I need as a multi-instrumentalist playing with a guitar-playing partner.

Compared to the coverage I can get with just a single K10 speaker -- not to mention being able to add a second one if I really need more coverage -- the only thing an acoustic amp offers is fast setup and teardown. Everything in one box, no extra cabling required. It does take me a few more minutes to hook up cables with a mixer + speaker, but with a loomed AC/XLR cable like the ProCo Siamese Twin, setup and teardown doesn't take more than a few minutes.

[Mark Seale]

We've recently started using the QSC K10s with everything from duo to our full country band also with the Allen and Heath small mixer. I'm continually impressed with their quality and the sound. If you can get by with just an amp, I currently use an Acoustic Image Corus and my wife uses and AER compact 60. They are both very nice and have dual inputs and the sound quality is fantastic.

[almeriastrings]

You know what I'm going to say...

For solo/duo work the Fishman SA220 is my choice. Two very versatile input channels, mics with +48v, mic + instrument, or two instruments, decent sounding reverbs, direct outs to sends to larger PA if needed, extra inputs too if required via separate mixer, phase reverse, notch filtering, 3-band-EQ on each channel, channel mute with remote, and many other useful features. Essentially similar in functions to the 'Loudbox' range, but employing line-array concepts and giving really outstanding, even dispersion. Very easy to carry (in a kind of golf-caddy thing) and super fast to set up. I like them (have two) and for the kind of gig under discussion, they work brilliantly. Should add that for a smaller gig, you only need need one.

[mandroid]

There is a Chorus , reverb and a feedback supressor in the Roland AC stuff , I own the 60

It can mount on the speaker stand , but the controls are hard to reach up there..

[Ed Goist]

Oh, good point about the effects. I tend to set the sound one way and just leave it alone from there. But, I do think I like a touch of something (reverb or chorus?) in my vocals.

I sit when I perform, so moving around isn't a consideration or issue. Hence, I've wondered if I'd be better off with one really good mic to pickup everything (instruments, vocals, harmonica) as opposed to the two Heil PR20UT I now use (and really like). This would mean less mixing, wouldn't it? Thoughts?

[TonyP]

I had(just sold) a amp/one box PA called a Centaur 440. It's 65w had a mic ch, a ch made for a P/U and even a ch for a mp3 player. It sounded great, but was not good for us because you couldn't get it high enough in the air like a regular PA speaker. So it was easier to set up, but was not able to be loud enough to over come it not being able to get over the heads of the crowd. That meant we blasted the front row and everybody else said they couldn't hear us. So now it's smaller speakers and a small mixer. I would like to go to a Fishman or something like that. But right now it's too much $$$.

It's always a trade off Ed when you go with single mic. If you don't mind having your speakers out in front where you can't hear them and you don't need monitors, and it's quiet you could get away with it. But single mic is much more sensitive so it can pick up you and your guitar, but it's also more likely to pick up crowd noise and feedback. It will take some setup to balance right with your voice and guitar and IMHO sitting down in this case is good as it means you'll be consistent in your sound once you get set up. There are some cheaper mic's you could try like the AT 2020 or 3035.

[Mark Seale]

I think two inputs is still the way to go. Most of the recommendations so far will have separate eq.

[Eddie Sheehy]

I use either one or two SA-220 SoloAmps with a Zed 10 mixer. I have no idea what I'm doing but it seems to work...

[mandroid]

Look at the back , many offer another Input , add a small mixer,
to use the Power stage and speakers in the acoustic amp.

[Ed Goist]

I use either one or two SA-220 SoloAmps with a Zed 10 mixer. I have no idea what I'm doing but it seems to work...

Eddie, remember, I've heard you sing & play...You could play through a tin can attached to a string and it would sound great.

[foldedpath]

Something I forgot to mention:

Another advantage of compact mixer into a PA speaker, or even into a line input on an acoustic amp, is if you normally play seated. Having a little mixer right next to your chair is very easy to adjust. You're at some distance from the speakers, so if you lean over with your instrument strapped on to make mixer adjustments, you're not increasing feedback risk

If you use an acoustic amp, you have to walk over to the amp and make adjustments. That's hard to do without triggering feedback if you're playing the mandolin at the same time, while making those adjustments.

I suspect that in 5 or 10 years, every acoustic amp will come with built-in WiFi and you'll be able to adjust it from a distance with your smartphone or iPad. But we're not quite there yet.

[Ed Goist]

Something I forgot to mention:
Another advantage of compact mixer into a PA speaker, or even into a line input on an acoustic amp, is if you normally play seated. Having a little mixer right next to your chair is very easy to adjust. You're at some distance from the speakers, so if you lean over with your instrument strapped on to make mixer adjustments, you're not increasing feedback risk ...snip...

Yes, I can see how having the mixer right there would be very helpful. When you run through a mixer and into powered speakers how do you set the speaker outputs and tone controls? Everything flat? Everything pegged?

[Dan Hulse]

Hi Ed, likewise I do not play solo but with a 2-5 piece acoustic. I have used a variety of amps, but now go through a K&K pure into a Bose L2, sometimes through a small mixer. A small PA is way more versatile, mix & match, add delete gear depending on need.

[foldedpath]

When you run through a mixer and into powered speakers how do you set the speaker outputs and tone controls? Everything flat? Everything pegged?

Normal practice is to set the powered speaker at whatever the manufacturer calls the "nominal" level, where it's basically running flat-out at full power, and you make your adjustments at the mixer. If the powered speaker has any tone control, like the Vocal/Boost/Flat switch on the K10, I always leave it flat and make all EQ adjustments at the mixer.

On the K10's, you plug your mixer output into the Channel A Mic/Line input (making sure that the little switch below it is set to "line" and not "mic" or it will really mess you up). That means the gain knob is turned to 12:00 O'clock where it says "Signal 0db."

On this particular powered speaker series, that means you're neither boosting nor cutting the mixer signal into the speaker's power amp section. To further complicate things, you can dial that input gain past the 0db point, and add another 10db gain from an internal preamp ahead of the power amps. Some people run these speakers that way... DJ's, probably. I don't. I like setting it for 0db, and then I have that +10db boost available if I ever find the speaker isn't giving me enough in some situation like playing outdoors. But I've never run into that. It's just a safety cushion.

So that's the speaker setting. From there, I adjust the input gains on the mixer so the channels aren't overloading, and adjust the speaker's output by how far I dial up the master fader on the mixer. If it's a really small venue like a restaurant, I might dial back the input gain knob on the K10 powered speaker to the 9-10:00 position, so I have enough headroom for adjustments with the mixer's fader while staying at a low speaker output level.

This might sound a little complicated, and there are some additional things to know about gain-staging when combining mixer outputs with other gear, but it's easy to figure out, once you start messing with it. And the people here in the Cafe are always available to help!

[foldedpath]

At the risk of scaring away anyone considering a compact PA, here's a funny situation I ran into a couple of years ago, using a pair of K10's and a compact mixer. This is how it can all go pear-shaped, if you're not careful and know your gear:

The gig was a wedding in Leavenworth, Washington USA at a horsey/whitewater rafting vacation resort. We were hired to play pre-ceremony and post-ceremony music acoustically, and then an hour of cocktail hour music before the dinner at a different area, where we set up our PA. Two K10 speakers on stands, and a small mixer (Soundcraft MFXi8). Very long, all-day drive out and back, but good money for the gig.

After setting up the PA and getting everything wired for a sound check, I got what sounded like no signal through one of the K10's, while the other K10 was nice and loud.

Drove me nuts for about 10 minutes, trying to figure out if it was a bum cable, bad output channel on the mixer, or a dead powered speaker. I was about to go through the dreaded cable swapping dance to figure it out, when I looked up at the other (non dead) speaker, and noticed the Mic/Line switch had been switched to Mic instead of Line. So that speaker was getting an additional gain boost that shouldn't have been there, making the other speaker sound very quiet when fed the same signal from the mixer. The problem wasn't that one K10 was dead, it was the other one had been set to an inappropriate input from the mixer! My guitarist partner had probably bumped the switch when lifting the speaker up onto the stand. It couldn't have been me... no, no way.


You're going to see more of these potential pitfalls with powered speakers, as they add what are basically their own mini-mixers in the back.

How to prevent it ever happening again? Easy.... I put gaffer tape over every switch option on these K10's like Mic/Line, Vocal/Boost/Flat, Ext Sub/Norm/Deep, and I even taped the input gain knob so it's up at 12:00 O'clock. If you get powered speakers to use with a compact mixer, learn how they work, and tape off every setting you don't ever need, or want.

I know this makes the speaker design sound flawed, but what I've always liked about these speakers is that there *is* an actual mic preamp on each one, as well as a second line input, and I have a few SM-57's in my emergency gear bag. If my compact mixer ever went down, then I could ditch my clip-on DPA 4099 (which need phantom power), rig up an SM-57 for my mandolin and plug my partner's guitar into the other input as a backup. No Eq in that mode, but we'd have volume balancing. Redundancy is good!

[Mark Seale]

LOL, FP I had the same one quiet (silent) one loud issue our first time out with the K10s. It was driving me nuts as I had the whole band coming up to tell me that one side wasn't working while I was troubleshooting. Extremely helpful. I hadn't thought to tape the controls, but I think that's a great idea.

From a control standpoint, I have been setting the board levels prior to setting the gain on the K10s. My thinking was that would give me the optimal signal from the board. I think I'll play with your approach the next time I have it set up.

[almeriastrings]

Yes - generally, if you set the gain on powered speakers or power amp at '0db' this will give you very good headroom and plenty of room for adjustment from the master channel faders. Note, though, that not all brands of powered speaker as as helpfully (and accurately) marked as the QSC's. Some have no markings at all around the gain knob, and on others the markings bear little relation to the electrical performance! So, in those cases you have to either measure it, or best-guess it. In the latter case, it tends to be somewhere around the 50-60% region.

If you have the speaker gain too high, you will be running your mixer outputs too low. A decent signal strength on the main outs will improve signal to noise ratio, among other things.

[Ed Goist]

Carvin AG200



I have never heard a Carvin amp or audio component that I didn't think sounded great. Granted, I've never heard their acoustic amps, but with a street price of $450, I am seriously considering this as a beginning sound rig for my solo acoustic act.

Has anyone here played through one of these?

[Mark Seale]

I haven't seen that, but if you get it, we need a full report!

[foldedpath]

Ed, I haven't heard that Carvin acoustic amp, but judging by the specs and photos, I can see some good things and some not-so-good. On the positive side, the weight is reasonable, and it includes a speaker stand socket on the bottom. That takes care of my main objection to acoustic amps vs. compact PA's, the way you can get a PA speaker up in the air for better audience coverage.

On the negative side, that's not an ideal shape to put up very high on a speaker stand... might be a little tippy? Get a decent speaker stand with wide legs if you go that way. Without a waveguide (horn) or angled speakers like some of the "tower" systems, there won't be as wide a coverage of the audience, but that's probably still okay for coffee shop gigs.

The main thing I don't like is the max input impedance rating of 500K Ohms. That's on the low side, for passive pickups (if that's what you're using). You might need a DI or preamp/DI like the LR Baggs PADI to get the best results with a passive pickup, especially if you're on a long cable run to the amp. I don't know why anyone these days would market an "acoustic amp" without a 1 MegOhm or better input impedance.

[Ed Goist]

Thanks so much for the feedback (ironic word choice, I know )!

...snip...
The main thing I don't like is the max input impedance rating of 500K Ohms. That's on the low side, for passive pickups (if that's what you're using). You might need a DI or preamp/DI like the LR Baggs PADI to get the best results with a passive pickup, especially if you're on a long cable run to the amp. I don't know why anyone these days would market an "acoustic amp" without a 1 MegOhm or better input impedance.

This will not be a problem for me, as I have the LR Baggs Para DI, and I pretty much "never leave home without it". What a fantastic piece of equipment! I consider it one of my most valuable and trusty pieces of gear.

Also, I very much envision this acoustic project as an "all microphone" thing. My intent is to keep things as stripped down as possible.

[Dan Hulse]

I can't vouch for that particular product, but I did recently purchase a 12 channel non-powered board from Carvin that I am very pleased with. Lot's of functionality for the money.

[Jim]

Having just done this , both ways, last night I'll share my opinions. Last night I played an on the street program with a 2 piece band that had some people sit in as well, followed by a duet at a Pizza shop. I used a 4 channel powered mixer with speakers on stands for the street gig. The Bass player had her own amp and didn't need to plug in. I ran my mandolin and guitar through a D/I box into the PA and had a vocal mic. I also had 2 channels available for some guitar playing friends who sat in on a few songs. This rig works great and, when space allows , lets me run a monitor (I often use a small acoustic amp for a monitor) . The Pizza shop was only a block away from the street performance and had a very small stage that is elevated about 4 feet. The time pressure ( I had to tear down the gear on the street and set up in the pizza shop in a half hour) made me go with an acoustic amp for the duet act) I chose to plug in through a DI again for this job as well since it was going to be a very noisy crowd. For fast setup it's hard to beat an acoustic amp. Both rigs sound great. When I choose to run 2 mics with the acoustic amp I run the instrument mic through an ART 12ax pre-amp which gives me the second xlr input required. I have also , in quieter environments run a LDC mic through the ART and in to an acoustic amp set out front and up on some stools or chairs. If I only had to have one, it would be the PA, it's far more versatile. The mixer to Powered speaker is my plan for the future, right now I have the mixer but am still saving for the speakers. The small PA is much easier to carry ( because it's in individual pieces) than all but the smallest acoustic amps and allows you to run a monitor. Also, as FP points out, you can have the mixer right beside you to adjust as needed and the speakers far enough away to not feedback when you go to adjust the mixer.

[Tim2723]

Hi Ed, sorry to be late to the party. I see you've gotten top notch advice that you'd expect. I have a question though. If you're going out solo with a couple of mics, why not just add a small powered mixer (200 watts, four channels) to your 10" speakers from teh other set up? I've had one of these bouncing around the length and breadth of NJ for five years and it still works like new:

http://www.musiciansfriend.com/pro-a...condition=used