Jay Mitchell and the power of flat response

[youngmic]

Here's another one: http://www.fullcompass.com/product/396060.html

This is crazy. I should probably just acquiesce to the reality that I will never be able to effectively audition all of these high end to exotic options. And I don't have the cash to be buying and returning these things. I'm very close to simply giving in and accepting that the JBL612's will work for me until I'm significantly wealthier - and more patient.

 

[TheOtherDave]

Any thoughts on/experience with these:

http://www.l-acoustics.com/products-12xt-39.html

http://www.l-acoustics.com/products-112p-41.html

I haven't had a chance to use either of those speakers, but FWIW the L'Acoustic 115XT HiQ driven by their LA8 amp sounds fantastic compared to a Clair PM12 driven by half a Crown CTs 2000 or 3000. For some reason the L'Acoustic wedges sound a bit chorusy, but their highs are so much smoother that I don't care. Of course, the problem could be that I'm comparing them to the Clair PM 12, not the AM 12, or maybe it's because L'Acoustic makes both the speaker and the amp and they've loaded its on-board DSP with presets for all of their products. Crown's CTs amplifiers might make everything sound a bit harsh. I've never used one box to compare different amps, but people who have, who may or may not be right, tell me that the CTs series aren't the best for high frequency stuff. So I really can't tell you why the L'Acoustic wedges sound better than the Clairs, just that they do.

 

[Jay Mitchell]

what is the general opinion on DSP to achieve flat response

It is a fact that DSP can be a useful tool for tailoring the response of a loudspeaker. As with all tools, the quality of the result is more a function of the person using the tool - the loudspeaker designer in this case - than of the specific tool (s)he chose to use.

 

[Jay Mitchell]

I've heard Jay's rig, in a small-combo context at a roadhouse type of venue. At that event, Jay brought his FRFR cab, and was also experimenting with using a pair of small line-arrays surrounding the FRFR cab in a W/D/W arrangement.

All correct. The line arrays are also Frazier products, and they are my trio's PA speakers.

I thought it sounded great.

Thanks. Given that my rig - which includes the monitor and the line arrays - is as transparent as it is, that statement says you liked my presets/guitar sounds, because that is exactly what you were hearing. With my rig, there are no excuses. What comes out of it is what you put into it.

But then, I was there for the music (and to meet Jay), and wasn't doing any critical listening - nor was this exactly a controlled environment! :-D

I certainly appreciate that, and I really appreciate your having made the effort to come out and listen.

 

[scotts]

(youngmic) This is crazy.

Your taking in a lot of data and trying to immerse yourself to a new depth. Absorb the learning and don't obsess about the outcome. Take your time and allow some time to laugh at yourself.

I regularly catch myself taking this whole guitar thing way too seriously. Read something like The Pelican History Of The World by J.M. Roberts and revel in your and mine ultimate insignificance. Contemplate a time when there was no such thing as an amplifier. What version of G.A.S. did Mozart have?

In short: Take a breath and cultivate a long view. Takes the pressure off for me.

(youngmic) I should probably just acquiesce to the reality that I will never be able to effectively audition all of these high end to exotic options

Excellent advice. The easy part of FRFR is that you only really need to find one solution that works for you. Find something you really like, run with it, and spend your creative time painting with the Axe and more importantly, playing. If you come across something that significantly outperforms what you currently have, step up if you can afford it.

(youngmic) I'm very close to simply giving in and accepting that the JBL612's will work for me until I'm significantly wealthier - and more patient.

Take your time and have fun. Forget about speakers for a minute and learn to play something new. Go take a guitar lesson from someone (regardless of what level you play at), get together and make music with a friend, etc.

 

[Rampant]

Jay,

You clearly really know your stuff! Do you have any suggestions for us about managing with less exotic equipment? For instance, most people here seem to be running around with ~1k boxes (including Scott it seems from the original post). Any tips on tweaking eq's, etc, in order to get the most out of them? What steps can be taken to make speakers sounds as good as possible given the limitations of budget and the fact that most people using the Axe are not sound engineers and (speaking for myself) would have a hard time sorting through all the data and making sense of it.

 

[Ventanaman]

I do really enjoy these technical threads, although they can get out of hand a bit.

I have a serious question though, why is a multiple transducer with a cross over (FRFR enclosure) needed to replicate/recreate what is done so well with a single driver (guitar speaker)? Is it because FRFR users intended to replicate multiple drivers (via IR's) over the course of a performance or is there another reason?

 

[youngmic]

This has been a very helpful thread. Let me share a bit of my mindset both as therapy and in the off chance it is shared by others on this board. I have the resources to buy a monitor in the $3000 range, maybe even two. But it would be a significant purchase for me and I don't have the time or money to be buying and selling them until I find the right one. I am not a professional musician but do play regularly. Tone is very important to me as it is a key source of my own inspiration. It's also important to me that the sounds I make are pleasing to others. This can be accomplished with a very wide range of equipment.

However, I also appreciate fidelity. I am not an audiophile (although I do enjoy audiophile grade equipment), and I am not a professional sound engineer. But I can quickly say what I like and what I don't like. As many have said, with traditional guitar rigs, you get a pretty limited set of options within which to work. If you don't like it, buy another cabinet, try a different head, grab another stomp box (although I'm not much of a stomp box guy). I've never really had to concern myself with the accuracy/transparency of a speaker. Even colored sound can sound "good". But what I want here is complete transparency so that I'm not worrying about dialing out coloration. I "believe" I've found a decent option here in the sub $1000 JBL612. But I don't know if I'm right. I am not experienced enough to trust my own judgement in this regard.

I look at high end powered solutions from EAW, Meyer, Turbosound, RCF, and L-Acoustics and think that surely one of these has achieved something approaching the transparency of Jay's design. But there's no way to tell.

In the end, this differs little from the quagmire of guitar amp/effects options that exist out there. But somehow, the potential excites me to the search again. I have in my mind the idea that if I can find the most accurate and transparent speaker out there and match it with the Axe-Fx, I may be done with the search once and for all (at least until Fractal releases the Axe-Fx II!).

But Scotts, you offer good advice. I'm sure my frenzied research will subside soon and I will settle back into enjoying the music.

 

[Rex]

It is a fact that DSP can be a useful tool for tailoring the response of a loudspeaker.

@Jay: Given that variations in amplitude response are usually accompanied by phase shift; that EQ circuits (analog ones, anyway) introduce their own phase shift, and that phase in loudspeakers is influenced by more factors than the just the frequency response of the drivers:

1. Are DSP response-tailoring systems able/likely to impart any kind of meaningful phase correction?
2. Does it matter?

 

[LMO]

But Scotts, you offer good advice. I'm sure my frenzied research will subside soon and I will settle back into enjoying the music.

I understand that Coda is planning to start distribution in the US soon, so the AP-12 may be worth a look. :lol

 

[Rex]

Absorb the learning and don't obsess about the outcome. Take your time and allow some time to laugh at yourself...

What version of G.A.S. did Mozart have?...

In short: Take a breath and cultivate a long view. Takes the pressure off for me.

...spend your creative time painting with the Axe and more importantly, playing...

Take your time and have fun. Forget about speakers for a minute and learn to play something new. Go take a guitar lesson from someone...

Excellent advice, Scott. This stuff should be part of a required Guitar 101 course for everyone who picks up a guitar.

 

[Rex]

...why is a multiple transducer with a cross over (FRFR enclosure) needed to replicate/recreate what is done so well with a single driver (guitar speaker)?

Excellent question, Ventanaman. If you only want to create the narrow range of tones that a single guitar cab can provide, you don't need any FRFR solution. But if you want to create the tones that a variety of guitar cabs are capable of, you have a choice: buy all those cabs and haul them around with you, or go with a FRFR speaker.

Guitar cabinets color your tone in a huge way. They make lousy FRFR speakers, and they have raggedy, jaggedy response curves. That's because a single kind of driver can't effectively reproduce the whole range of low to high frequencies with reasonable fidelity. That lack of fidelity translates to some cool changes to the amplified tone of your guitar, but they're highly flavored changes that give the cab its unique sound. You can reproduce those changes with the Ax-FX cab simulations. To use those simulations, you need a flat-response speaker system to make sure your speaker doesn't add its own colorations to the already-colored cab sims. And you can only get that kind of fidelity with multi-driver, crossed-over systems.

It's similar to the visual arts. If you want to create a certain oil painting, all you need is a set of oil paints. But if you want to be able to produce an image that looks like that oil painting, and still be able to produce an image that looks like another artist's (or your own) oil paintings, and another artist's watercolor paintings, and another artist's pencil sketches, you need a high-fedility photographic or digital medium with enough bandwidth to be faithful to all those colors, styles and textures.

Another reason: Some of the effects introduce frequecies that aren't in the original signal. And a lot of effects are best applied after the guitar cab. It can be a real pain to do that unless your "cab" is contained within the Axe-FX.

 

[Jay Mitchell]

@Jay: Given that variations in amplitude response are usually accompanied by phase shift; that EQ circuits (analog ones, anyway) introduce their own phase shift, and that phase in loudspeakers is influenced by more factors than the just the frequency response of the drivers:

We'll address the "givens" first:

1. Many variations in the amplitude response of loudspeakers are not accompanied by phase shifts.

2. When amplitude variations do cause phase shift, they are most often due to minimum-phase phenomena.

3. Most "EQ circuits" - including DSP-based emulations of analog circuits - are themselves minimum-phase in nature. If you correct an amplitude error in a minimum-phase system (the speaker) using another minimum-phase system (the "EQ circuit"), you correct the phase response as well as the amplitude response.

Now, in light of the additional information above, I'll address your questions:

Are DSP response-tailoring systems able/likely to impart any kind of meaningful phase correction?

Yes.

Does it matter?

Sometimes.

 

[zslane]

And a lot of effects are best applied after the guitar cab.

As a newbie to the Axe-FX, this is something I don't quite understand. I've seen many layouts where effects blocks are placed after the cab, something not done with a physical rig. I suppose this is somewhat analogous to inserting effects at the mixing board in a recording studio, where the effects are altering the post-cab/mic signal, but I'm not accustomed to thinking of those effects as part of the guitar rig. I'm trying to grasp why we would want to endorse a virtual practice that has no real-world equivalent other than "because we can". This seems like either an indication that we are having to resort to funky practices in our Axe-FX layouts to compensate for weaknesses in the simulations, or that we are taking creative advantage of the "its all just a signal" nature of the Axe-FX's digital data pipeline.

Could someone explain this to me in a somewhat technical manner? A way that goes beyond, "we do it because it sounds good"?

 

[hippietim]

Great thread Scott and Jay!

Not knowing what Jay would need to charge for a FRFR rig it's hard to say if it's worth it to me or not. I'm not afraid to spend money on gear but I have limits just like anyone else. I would love to hear a ballpark price range even if it's +/- a good chunk of change.

But Jay would probably have to be more than a little insane to get into this market (and I'm not saying he isn't ) - guitar players are a pain in the ass when it comes to gear. I always assumed that when we got older and wiser folks would figure out that your rig is really only as good as the weakest link. I'll never understand the reasoning behind spending $2000 on an Ultra, $700 for a MIDI pedal, and then asking for the cheapest FRFR speaker. And at least one of the guys I know of to ask that question was replacing a Bogner Ecstacy, Bogner 4x12, and probably about $1000 worth of pedals. But that'd be Jay's market.

Having said that, Jay, I want a Frazier. I've not heard it. I don't know what it looks like. I just want it. Maybe two. Ideally in purple.

 

[hippietim]

"we do it because it sounds good"?

Actually, that is the reason. I'm sure someone can come along and give you a bunch of technical mumbo jumbo but in the end the reason is because it sounds better.

Also, many pros do run effects post cab. Go look at Michael Landau's rig - he has a mic on his main cab that sends the mic'd signal into effects processors and out to his "wet" cab(s). But a lot of folks run delay, reverb, etc. on the signal from the microphone.

The reason more folks don't do it is because it is quite a bit more work, money, and more gear to haul around. When you have nice budgets and roadies these things become attractive. The Axe-FX let's you have these capabilities without additional gear.

 

[Jay Mitchell]

I've seen many layouts where effects blocks are placed after the cab, something not done with a physical rig.

It's done all the time, both in the studio and in live performances. It is extremely common for time-based effects - e.g., delay, reverb, chorus, pitch shift, flange - to be placed post-cab. In addition, you will often find compression and/or limiting after the cab. The fact that you cannot easily do that with your basic tube amp is one of the major downsides of that type of rig, and it is one of the reasons that many heavyweight players do not confine themselves to that type of rig.

I suppose this is somewhat analogous to inserting effects at the mixing board in a recording studio, where the effects are altering the post-cab/mic signal,

It's not "analagous," it is identical.

but I'm not accustomed to thinking of those effects as part of the guitar rig.

That concept - post-cab effects as part of the rig - has been implemented, both in the studio and in live performances, by a substantial number of major players since the 1970s.

I'm trying to grasp why we would want to endorse a virtual practice that has no real-world equivalent

We are not. There are many "real-world equivalents," and they represent some of the most highly respected, if not better-known, guitarists there are.

 

[frankiev]

Scotts , Im also using the turbosound TSC 59 . I skipped to the end of this long thread so forgive me if you already answered this but did you try to eq the TSC to get it close to Jays setup . If so would you please post the settings

 

[Rex]

We'll address the "givens" first:...

Now, in light of the additional information above, I'll address your questions:

Yes.
Sometimes.

Thanks, Jay! That helped, though I had to do some research on minimum phase to get what you were saying.

If I understand correctly, a DSP-based EQ solution tweaked to correct the amplitude response of a speaker will also correct its phase response, to the extent that the amplitude response is the result of minimum-phase phenomena. Is that correct?

Can you give an example of a non-minimum-phase phenomenon in a properly-functioning (e.g., no torn spider flapping in the breeze, etc.) speaker system?

 

[jproxu]

In following some of the links provided, I've noticed that several high end companies like Coda(AP12), L-Acoustics(12XT) and RCF(NX-12) offer the FRFR with one coaxial speaker vs separate horn woofer combo. Is this a better way to go? Will these get me close to Jay's system? Like many others on this thread, I'd love to purchase one or two of Jay's. But if that's not possible then I hope Jay can recommend a close second or third in the high end market that he would purchase if he had to choose from one of the above or another manufacturer regardless of price.