Lots of great analysis on the bass side amp for the Chapman Stick with Damon, Randy, Samson, Rob and myself. There is a lot to know about getting an amp that will capture the full range of the bass side on the Chapman Stick. Where to start?

Start here!

Rob laid out some basics to start on the range of the Stick, impedance, voicing, compression, specifications for frequency and a great primer on graphic and parametric EQ.

We looked specifically at ART, Carvin and HK amps. Lots of features and details covered, some of which could or would be important based on what your specific requirements were (weight, power, features, etc.).

Very enlightening. Seriously, if you are even thinking about a new bass amp, give yourself the opportunity to review this session and hear the group talk through the options which also covered some bits on pickups as well as speaker enclosures.

The final 3 minutes of dialog gets whacky, which I expect we will edit at a later date. For now, we've got some great content out there and we hope that you enjoy it!

I will write the remaining discussion points in this thread, a bit later, and questions can be posted here.

By the way, Gene, you meant "GK amps" (i.e. Gallien-Krueger).

Prologue
The are a few things I want to point about before I continue where scheduling forced me to stop (in the episode).

Product Links
Here are links to the products I mentioned by name:

• ART Pro Channel II
• fdeck Series 3 HPF-Pre
• Carvin B2000 Bass Head
• Carvin BX1600 Bass Head
• Gallien-Krueger MB Series Bass Heads
• Creat ProLite 2.0 Power Amp
• Peavey IPR2 2000 Power Amp

More About Compressors
I made particular mention of the "five knob optical compressor" in the ART Pro Channel II; if you do not understand what that is or why you might want it, check out this excellent YouTube video discussing compression and its proper usage. It was made almost a year ago by an English busker who was once a producer and studio engineer.

Specific Corrections

• At 31:28, I meant to say "resonant peak" (not "resonant frequency").
• At 56:55, I should have mentioned that the problem Samson discussed gets to heart of speaker cabinet neutrality (as opposed to voicing) and frequency response.
• I repeatedly misstated the quantity of EQ bands on the ART Pro Channel II: it has four bands, with two semi-parametric middle frequency bands.
• I said that you are not likely to find more than five bands of EQ on anything, thus it is worth noting that the Carvin B1000 and B2000 bass heads each have six bands.
• The Gallien-Krueger MB Series heads are far from neutral.

Speaker Cabinets
Powered PA Speakers
This is a topic I know Gene wanted me to discuss specifically, and I am sorry that we cannot have a live response to what I am about to say: with regard to power considerations and the practical application of Hoffman's Iron Law, powered PA cabinets are often the the worst of both worlds. I know many Stickists currently use, and have used, powered PA cabinets with good results. My point is not that these products are all bad, but that we can do much better.

Consider the QSC K12. This is a two-way cabinet which, as I mentioned in the episode, means that the woofer has a lot of frequencies to cover between the Stick's lowest fundamental and the beginning of the tweeter's range. Also, the enclosure is small. These factors combine with Hoffman's Iron Law to indicate that the QSC K12 must sacrifice low frequency response for sensitivity. Sure enough, the frequency response is specified as 52Hz to 18kHz: this is quoted at ±6dB, however, not the usual ±3dB. In fact, the QSC K12 is already -10dB by the time it reaches 48Hz. The 1000W power amp is split in two: 500W goes to the tweeter, and 500W goes to the woofer. That is a ridiculous amount of power for a tweeter, since compression drivers are quite sensitive. You should instead think of this as a 500W amplifier feeding a 500W speaker cabinet, which means that you should be very careful to maintain sufficient headroom. I will come back to the QSC K12 in the conclusion, but I want to discuss frequency response a bit more before I move on.

The K series designs sacrifice low frequency response to such an extreme degree that even the subwoofer is -10dB at 44Hz, and that is with the 3dB boost created by the acoustic coupling of the dual 12 inch woofers. The subwoofer responds all the way to 148Hz (using the -10dB specifications), which means that the designers chose to increase response in the range that tricks our brains rather than truly go low: this indicates that the sub's woofers lack sufficient excursion capabilities to go low, and they might even be the same woofer used in the K12.

As exemplified by the QSC K12, I recommend ignoring powered PA speakers altogether.

The Part Where I Talk About Greenboy Designs
Dave "Greenboy" Green's designs combine wide frequency response, high power handling, and (relatively) light weight to make a much more practical compromise with Hoffman's Iron Law than the QSC K Series: thus completely bypassing what is typically considered good bass cabinet performance. Whereas the vast majority of speaker cabinets maintain similar sensitivities, reducing low frequency response in the smaller variants, the Greenboy cabinets have the same frequency response and vary in sensitivity. You will notice that there are no frequency response or sensitivity specifications for Greenboy cabinets; this is because Greenboy is adamant that virtually every speaker cabinet specification you have ever seen has been inaccurate, even downright nonsensical. When asked about frequency response, he might respond with an explanation of crossover design. When asked about sensitivity, he might elaborate on the complexities of quantifying that aspect of speaker cabinet performance and point out that response at 1kHz with 1W of power is meaningless in the context of low frequency signals being amplified with hundreds of watts. As such, you have to look at the design itself.

Greenboy's fEARful cabinet designs (linked directly in case you need it) are available to the public for non-commercial use, meaning that you must become an Authorized Builder to sell cabinets commercially: you are free to gig. This is a three way design, which uses woofers with a very high maximum excursion (which relates to low frequency response in that more excursion is needed at lower frequencies and higher volume levels). The dedicated midrange driver enables the woofer to extend lower, since the woofer does not have to make up the gap to the tweeter's response. Furthermore, notice that the cabinets are relatively large for the woofer diameter, with generous porting. This also helps the woofer to make the most of its capabilities. Whether you build or buy, I recommend all Stickists opt for the newer True Three Way crossover (as opposed to the original Cheap But Good crossover). Speaking of which, there are three ways to get a fEARful cabinet:

1. Building from scratch: you are free to shop for parts where you like, but Leland Crooks makes things very easy at Speaker Hardware.
2. Building from a flat pack: Leland sells flat packs of pre-cut Baltic Birch, including "Deluxe kits" which include almost everything.
3. Purchasing from an Authorized Builder: in particular, David Homer has written a lot on his Gigmaster Soundworks site.

Greenboy's Fearless cabinet designs are not public, thus they can only be purchased from Authorized Builders. The Fearless cabinets are less neutral than the True Three Way fEARfuls, but they still take EQ extremely well. You might want to consider the Fearless designs if:

• you want a wedge option.
• you want maximum portability, as exemplified by the Fearless F110.
• you want an even smaller and lighter cabinet for the woofer configuration, particularly in the dual woofer designs.

Check out Ed Friedland's review of his Fearless F112 for Bass Player Magazine (he also made a video).

Conclusion
Costs
Just as more equipment can sometimes make things simpler than less complex rigs, thanks to greater control, more expensive equipment can sometimes save money because it covers more bases.

If you have a mixer, for instance, you could buy a True Three Way fEARful 12/6/1 and a Crest ProLite 2.0 for about $200 less than a pair of QSC K12 powered speakers. In fact, that price difference would cover the cost of a small mixer. You could use that rig all the way from your first practice to serious gigging before you needed more, effects aside, at which point you would just get a duplicate cabinet with a mirrored baffle to create an inverted stack at big gigs. Going the DIY route, you can get you need to build a True Three Way fEARful 12/6/1 (apart from clamps and such) for about $700.

A Greenboy cabinet is more cost effective than it might seem, since it can handle your melody side as well as anything out there.

Do You Even Need an Amp and Cab?
If you are not gigging or playing open stages, you would do well to put a few hundred dollars into an audio interface and a good pair of headphones. If you spend more to get a mixer which also serves as an interface, such as the Soundcraft Signature 12 Multi-Track, then you have a clear upgrade path for later gigging.

Talk to Us
Start a thread in the Equipment section before you start buying gear, just in case we can help you save time, money, confusion, and pain...unless you are looking for songwriting fuel.

Rob,

Thanks for all the great information on the FHF episode and here in this post.

Everything about the Greenboy cabs sound great except it really rubs me the wrong way that he doesn't publish frequency response curves. I am sure he used frequency specifications when he selected the drivers, crossover, cabinet size, port size ... so why shouldn't we see frequency data (the frequency response curve) of the total finished product? And to say that since other people's data is inaccurate he won't publish his data is crazy. He could publish his "accurate" data.

I am guessing the data isn't published because of one of these reasons:
1. He feels people won't understand his "accurate" data. I say that people in the know will understand and too bad for the others
2. There is something in the curve that he may not want to expose, or
3. He doesn't want to take the time and money to have the measurements done.

I'll try to end this on a lighter note with this conversations:

Joe: How do I select a flat speaker cabinet?
Fred: For starters, look at the frequency response curve.
Joe: Do you have any recommendations?
Fred: Greenboy is very good.
Joe: Can I see the frequency response curves?
Fred: No!

I understand where you are coming from; as such, I will share with you all I have (because, apparently, my fatigue prevented me from remembering to bookmark and/or save response curves I remember seeing posted by highly technical members of Greenboy's forum).

Here is a user-generated graph of a fEARful 15/6/1, and I did not remember to note which crossover it has. This is representative of the 12/6/1 as well, apart from SPL:


Here is a user-generated graph of a True Three Way fEARful 1515/66/1, the monster which can make empty 2 liter bottles roll, which the co-developer of the True Three Way crossover shared:


The only other graph I can reference at this time is a simulation of each fEARful design's SPL (with the Cheap But Good crossover) at maximum excursion, which is in the FAQ on the fEARful site:




I think that is the reason, actually. Greenboy gets a royalty from his Authorized Builders, but everything I have read (including advice from the ABs themselves) indicates that there is not much money in it.

Thanks Rob!

So here we go...I am not even sure how to ask this. I watched the melody side discussion and am about 15 minutes into the bass side amp discussion and loving it, by the way. If I am playing mono--not sending a separate signal to two different amps, but still want to satisfy what the bass side of the Stick wants and what the melody side of the Stick wants, what is the best coarse of action? I am currently using a bass amp to give some thump but also a PA speaker to keep the notes on the melody side bright. Keep in mind I am playing both sides of the Stick as one instrument: not bass and melody through different chains and amps.

It looks sorta like this.

Stick stereo cable out to channel 1 and 2 of a Macke 402-VLZ3. Then mono out to a Digitech multi effects pedal(just effects, no amp simulation). Then to channel 1 of a 1980's Peavey XRD 680s 8 channel PA(dont usually need 8 but that is what I own). Out of that via the two wholes in the back to a (Left side)PA speaker with a 12 inch and a horn, and (right side) a wedge monitor with slightly smaller dimensions. That is what I am hoping will satisfy the "guitar" range of the Stick. But I also send the same signal out the monitor output of the PA to an Ibanez? Soundwave65 bass amplifier. It does seem to create a pretty full sound, but I could wish a little more thump and less mud on occasion(like when I add some distortion or chorus)...

All this is just me trying to use what I have already bought over the years and not selling it all for a loss and having a GAS attack.

Please disregard if this is all so childish as not to dignify with a reply.

Mike

PS. Wow, after all that I forgot to get to the actual question
...

Does it make sense to send the same note(or each and every note for that matter) through all that speakerage? Just to make it(or them-it is often chords) sound as full ranged as possible?

PS 2.(not from sony) Then add on top of things I would like to play both a 10 string Stick in Baritone melody and a SG-12 in classic through the same stuff. On Saturday!

PS 3.(might be from sony, might not be) Rob, I think what we need here is not Skype lessons, but Skype sound consultation!!!

Get in touch with at your first opportunity, Mike. I hope we can discuss this in time.