phase question

[fingers]

I have been doing some gigs with a singer/songwriter and we have a few shows coming up in some big venues. I've been using a BassMax with her to good success. It lacks a bit of the woodiness and thump that I love about the Realist so I was thinking about blending the two through my AI. So if one were to mix two pickups there might be a phase cancellation issue right?

My questions.

What determines/effects this?

Does it change from room to room?

[Mike Arnopol]

Hey Marc
The interaction between the pickups is the biggest cause. Problem with simple phase switches is that they are in phase or 180 degrees out of phase. So if the nastiest part of the phase interactions are about 180 degees out, you're in business. Problem is that most problems are somewhere in between. Which is why on the new EA Doubler the phase control is variable between 0 and 180 degrees. But you might luck out and find the sound better at 180.

[adbass]

doesn't depend on the room as far as I know. You'd be able to hear a volume difference in specific notes if it's happening. again, afaik, waves in phase would give you a louder perceived volume and waves out of phase would give you less to no volume (complete cancellation).

EDIT: that is to say that certain notes will sound louder or softer due to phasing.

This is my beginners knowledge, so just wait till Francis or the Dr. chime in and make some corrections here.

[Ric Vice]

Originally Posted by Mike Arnopol

Hey Marc
The interaction between the pickups is the biggest cause. Problem with simple phase switches is that they are in phase or 180 degrees out of phase. So if the nastiest part of the phase interactions are about 180 degees out, you're in business. Problem is that most problems are somewhere in between. Which is why on the new EA Doubler the phase control is variable between 0 and 180 degrees. But you might luck out and find the sound better at 180.

The HPF buffer preamp has a phase switch and sometimes it can really help, but as Mike so aptly points out, it's either gonna work or it won't work at all. IMHO, phase switches work better on feedback from a single source. I think that's what the phase switch on the older Walter Wood's amps was designed for. But that's just my layman's take on the problem. A Variable phase control, like the EA doubler should be infinitely better than the switch.





Ric

[robgrow]

Unless they've changed it recently, the Bass Max is out of phase (opposite polarity) with most other common pickups such as Fishman, Realist, Underwood.

[fingers]

Thanks guys.

Originally Posted by robgrow

Unless they've changed it recently, the Bass Max is out of phase (opposite polarity) with most other common pickups such as Fishman, Realist, Underwood.

so does that mean I have to switch the phase?

I should really just plug stuff in and see what happens.

[Ed Fuqua]

Originally Posted by fingers

I should really just plug stuff in and see what happens.

While that may, in fact, work, I have no reason to believe it would work in theory....

[fingers]

Originally Posted by Ed Fuqua

While that may, in fact, work, I have no reason to believe it would work in theory....

[drurb]

The problem is that, even if the two pickups were placed at the same exact location, then the phase-difference would not only be, overall, somewhere in between 0 and 180 degrees but would likely vary by frequency. Now consider that the pickups would be at different locations. This will lead to a time delay between the arrival of any frequency at each pickup. A time-delay is, by definition, a (linearly) varying phase-shift with frequency.

So, what to do? Well, as you said, plug the stuff in and see if it sounds ok. You could get lucky.

[Eric Hochberg]

Originally Posted by drurb

So, what to do? Well, as you said, plug the stuff in and see if it sounds ok. You could get lucky.

Yeah, Marc, for a while I used a Realist and one element of an Underwood into a splitter box, no phase switch, volume controls or anything, and I got a really good sound.

[fingers]

Thanks for the input everybody. I'll report back when I can try it out.

question... should I try to have both pickups hooked up with identical cables or is that getting silly.

*I did a show recently at Martyr's here in Chicago and while they did a nice job with my sound (as they always do) I was reminded of a weakness of the Realist. Not great at higher volumes. I used the BassMax for a festival gig later with the same singer-songwriter and really was pleased with the more direct sound of the pickup in this particular setting. It was missing that sumtin-sumtin that is so alluring about the Realist though. I want both.

[Ric Vice]

Originally Posted by fingers

Thanks for the input everybody. ) I was reminded of a weakness of the Realist. Not great at higher volumes. .................... It was missing that sumtin-sumtin that is so alluring about the Realist though. I want both.

Marc,
My sentiments exactly. It's great at low and medium volumes. But if you continue to up the volume the bass frequencies build up and it turns to mud. Something also happens to the midrange at higher volumes it becomes nasal and pinched sounding.
I've had some success using the high pass filter on the HPF to control the bass build up, but once you start going that direction you eventually cut frequencies that are part of a good upright bass sound. In some ways it works more like a mic than it does a pickup. There's definitely a threshold celling that IMHO you cant pass without sacrificing tone quality. I like the bowed sound so much that I'm not willing to change out but I'm seriously considering trying a Toby Timber.

Ric

[drurb]

Yup, increasing the level does seem to produce problems in terms of tone. Once I switched to a Rev. Solo, EA iamp200 (with parametric tone-shaping) and a Wizzy 12, those issues were minimized greatly, if not virtually eliminated.

[jhelsley]

The bass has a lot to do with it…I use an FC/Underwood setup on two very different basses…

One channel phase reversed on my Woods cools everything out on my Pollman.

My NS hybrid is unplayable with both through an AI Focus. (No onboard phase control)


It’s great if it works. Definitely worth a try.

[Ric Vice]

Originally Posted by drurb

Yup, increasing the level does seem to produce problems in terms of tone. Once I switched to a Rev. Solo, EA iamp200 (with parametric tone-shaping) and a Wizzy 12, those issues were minimized greatly, if not virtually eliminated.

Durb,
For me at least, if the cabinet is smaller like the EA VL 108 or even the EA VL 208 things are easier to control. The Walter Woods amps also have great tone shaping, so that helps tremendously with bass buildup and midrange honk. Unfortunately, the Realist has volume limitations with my bass and amps that you can't exceed if you want to maintain the tonal characteristics of a Double Bass. Actually, I prefer the AMT mic mixed with the Realist, interestingly enough I haven't had any apparent problems with phase issues. Then agian, I never really play all that loudly with the Double Bass. It does seem like the smaller efficent cabinets like the Wizzy's and the Genz Benz have, yeild better results. At least for me.

Ric

[drurb]

Originally Posted by Ric Vice

Durb,
For me at least, if the cabinet is smaller like the EA VL 108 or even the EA VL 208 things are easier to control. The Walter Woods amps also have great tone shaping, so that helps tremendously with bass buildup and midrange honk. Unfortunately, the Realist has volume limitations with my bass and amps that you can't exceed if you want to maintain the tonal characteristics of a Double Bass. Actually, I prefer the AMT mic mixed with the Realist, interestingly enough I haven't had any apparent problems with phase issues. Then agian, I never really play all that loudly with the Double Bass. It does seem like the smaller efficent cabinets like the Wizzy's and the Genz Benz have, yeild better results. At least for me.

Ric

Yep, whatever works! I, too, don't push the level very high. Amplification for me, as for many other DB players, is a necessary evil that's there to reinforce the acoustic sound as best I can.

[fingers]

Well I tried it at my gig tonight and it seemed to work just fine. We weren't very loud but at moderate volumes it added some wing pickup bite along with the Realist thump that I am so addicted to. I'm with a slightly louder group tomorrow.

The real test will be two outdoor festival gigs I have Fri and Sat.

[fingers]

Louder worked really well. I did end up putting the BassMax through my Fishman Plat Pro before the amp 'cause the pre on the AI kinda sucks. It's nice to have the phase control too. The tone was killin'. HUGE and growly. Ah, more stuff to plug together again.

add the H-Clamp mic to the pa. Ah, simplicity.

[Uncletoad]

What you are describing is why I have preferred the Fishman Full Circle. I find it a happy medium between the Bass Max/Underwood and the Realist. The compromises seem very palatable to me.

[Mike Arnopol]

Combining the Full Circle with my ATM35 into the Doubler is the s%#t! A bit more definition, a bit more woodiness.