This post is mainly targeted at beginners with impulse responses and presents advices and tips from my own small experience with IRs, and from questions and discussions observed on different musician websites and forums.

Gear and signal path

You can check Impulse Responses Part 1 and Part 2 posts for the essential points to get started with IRs.

Let’s remind here a few important points : the final audio device you use for rendering your guitar tone plays a VERY important role in the overall result. Knowing you audio device and adjusting specifically your tone against it is important to achieve satisfying results. So let’s state the obvious again : playing on headphones, a monitor or a specialized FRFR speaker may produce quite different tone balances, and this is especially true for distorted, saturated guitar tones. The volume level plays also an important role : when playing alone at high volume -as an opposite to a band rehearsal or a mix situation- the tonal balance that we perceive is slightly different (more bass perception, louder sound is usually perceived as better by our ear). We may perceive harshness or unbalanced areas in the tone in a more pronounced way at higher volumes : so the CONTEXT and the VOLUME plays an important role. In other words, depending on the application, you will have to adjust your settings. For instance, in my personal case, when using IRs, I use 2 different headphones, two JBL 305 as desktop monitors, and one small JBL Flip to play at reasonable volume (with my computer off). One of the headphone is too boomy, the second one is a little bit too harsh and the JBL – which are not far away from the room wall- tends to become boomy and exaggerate bass as soon as you raise the volume…. So I do not hesitate to apply corrections to get a more balanced tone to these different devices : raising the HPF (low-cut) or lowering the 120 Hz frequency on the IR pedal or IR software, raise the treble/gain on my preamp, or even apply an EQ on the output track of the DAW to apply corrections.

Dial-up your tone

The second most important aspect is to become familiar with the gear you use and how the different controls are impacting your tone. For example, understanding how each of these components impact your sound will certainly allow you to opt for the right settings when chasing your (IR-based) dream tone :

  • voicing and output level of your guitar pickups
  • behavior of your overdrive, if you use one
  • voicing and behavior of your amp or pedal : how the tone is impacted by bass/mids/treble/gain adjustments, how the presence and resonance (if you have one) shape the whole tone, how the tone balance and gain structure is impacted when you raise the gain

Quite often, I find myself in the following situations :

  • way too much bass, producing a masking effect and some listening fatigue
  • or the opposite, when searching for a lot of attack, a tone too harsh with too much treble
  • quite often a “boxy” or “cardboard” feel : usually caused by too much mediums, which may work well for some speakers or IRs and certain genres (ie Hard Rock) but are disturbing for metal sounds
  • quite often not enough gain (a more crunch/mid-gain tone) , but I often stay in these areas for practice as I get more attack and definition, and usually less hearing fatigue
  • and occasionally too much gain, with a more than compressed distortion

So gain settings are really important : it is the same with a real cab, but IRs react differently and can be way more sensitive to this aspect, mainly because of the presence of the microphone in the equation, that will often brighten the overall tone. Raising the gain tends to raise the volume of treble frequencies such as 1 kHz, 2 kHz, 4 kHz or 6 kHz… : so it is common to iterate gain changes / treble / presence changes. In the first place, try to lower your gain settings when using IRs with a gear that you use otherwise with a real cab.

All amps and pedals are not equal : they do not react exactly the same way (dialing-up a Dual Rectifier is a different exercise than dialing-up an Engl or a Diezel amp). Some amps have a monstrous medium section, where some users will have to turn down the mids to the minimum in order to achieve their sonic goal… Others amps may already be scooped : lowering the meds with this kind of amps may lead to an unbalanced/muffled sound lacking attack and definition… Do not trust the buttons levels, even if you have the same amp as the one on the video 🙂 : trust your ears !

Another beginner’s trap (yes, I fell into it) is to immediately focus on the IR software EQ to start tweaking your IR tone : if you start using large EQ values (+7 dB here, -5 dB here, +8 there,…) and you need 5 notch filters, then it is probably the time to look for another IR…. Post IR equalization should ideally be light, and used for small corrections… That’s only my advice, and nothing prevents you from experimenting and using huge EQ corrections !

If you are not satisfied with the tone you get from IRs, I’d recommend to start by reviewing / revisiting your signal chain in the first place : are you using all the elements correctly, are your different levels OK ? If you have a DAW, you can try to use a graphical real-time EQ display to get some additional help by looking at your final tone shape : too much bass ? Too much mediums ?

Leveraging IRs

The first step is certainly to get an idea of the sonic territory of the different guitar speakers and recording microphones available : listen to demos and check if gear and recording details are provided, and of course, start experimenting by yourself. When you are attracted by a guitar tone that you spot in a song or a demo, check if you can find isolated sample of this tone (a guitar-only part of the song for example) : remember that the same tone, isolated at higher volume may present slightly different characteristics (and a mix-friendly tone is not necessarily a pleasant tone for guitar practice…).

The speaker+recording microphone duo dictates the tone that you will get from IRs : as stated earlier in this post, this shape will drive your gain and tone settings. The good news is that there are countless demos and examples to get an idea and get started (Youtube, Soundcloud, …).

As an example, the following blog post from Celestion presents popular speakers for metal :  https://www.celestionplus.com/news/what-are-the-best-impulse-responses-for-metal-update/. You will find the Vintage 30 in the list -of course- but many other speakers as well (G12T75, G12K100,…)

If you search for “speaker shoutout metal” on YouTube, you will find many interesting videos comparing speakers :

For recording microphones, it is a little bit more complicated to get used to their sound, especially if you have never experienced recording before. As beginners, we have no idea of the tremendous impact of the microphone on the guitar recording. Again, Youtube videos will help you in learning the differences and get an idea of the results : YouTube “guitar speaker mic recording shoutout metal”

If you are a beginner with using IR technology for guitar tone and you want to start practicing with this type of setup, some microphones may help you by providing a “full” tone, closer to a real cab-in-the-room sound.

For instance :

  • ribbon microphones like the Beyer Dynamic M160
  • some dynamic mics like the E906 or the SM7B which can provide more bass/body and be less aggressive than – the nevertheless excellent – SM57.

IRs of 4*12 cabs usually provide a fuller sound compared to smaller cabs : the larger volume provide more bass and resonance, which get captured in the IRs to a varying degree. The 412 IRs also present typically less harshness – but it is not always the case-. So you will probably get better results by using 412 or 212 cab IRs in the first place (at least for metal tone).

Available IRs reflect the real world market : the Celestion Vintage 30 is dominant and so it is one of the most used speaker for IR capture. While it is an excellent speaker for metal -and other genres-, you should probably have a listen and give a try to other speakers : they can provide different tonal balances, and eventually “better” results when paired with your gear than the classical V30 : some gear association are better than others, and the speaker/cab is -IMHO- responsible for at least 50-75% of the final result….

For example, if your amp is strongly medium or high-medium oriented, it’s association with a V30 may not be that easy : it can get very bright and aggressive, as the V30 has a proeminent medium section itself… So you may need multiple tweaks to achieve your tone (IRs tweaks, amp tweaks, additional EQ tweaks…) to avoid or contain harshness in that kind of association. In that type of situation, when using IRs, the very fist step is probably to select darker IRs, by using positions away from the center, and of course, test different IRs from different vendors, using different cabs : there are thousands of V30 IRs and they may lead to slightly different results when paired with your gear…

To broaden your sonic horizons, do not hesitate to explore alternatives to the Vintage 30, including :

  • The Celestion G12K100 (I am a fan)
  • The Celestion G12T75 (I am a fan also)
  • The Celestion G12M Greenback(s), which can have a very nice growl
  • The Celestion G12-65 (do you want the Metallica tone from Master of Puppets ?)
  • The WGS Veteran 30 (less aggressive than the V30)
  • The Eminence The Governor (darker than the V30)

So, play and test different IR positions if the IRs you are using offer this possibility (darker, brighter,…) and try to control and adjust the low-end and the resonance in order to get some beautiful chugs 😉

Another trap : when you have setup your gear for a specific IR and when auditioning / changing IRs, take the time to get used to the new tonal balance and revisit your settings… Else, you might dismiss interesting IRs, circle around and finally always get back to your original IR.

As an example, here are two videos to get used to the tone produced by the G12-65:

You can also take advantage of many tutorials and demos of gear usings IRs:

Conclusion

In order to leverage you gear with IRs, take the time to explore and get familiar with speakers and microphones and try to get an idea of the tone you are chasing : are you looking for attack, brightness, huge low-end, scooped mediums,…

When testing / auditioning IRs, let your hear accommodate the new tone and adjust your settings (well, if you feel like the IR is worth it and suited to your needs, of course).

And I’d recommend to explore beyond the Vintage 30 : it is an incredible speaker, which can produce a lot of different tone but other speakers may be worth the try.