Studio Diary #18: Recreating The Sound Of My Speaker Cabs Using Celestion Impulse Responses

Now that I’ve added the Two Notes Torpedo CAB M to my setup, the next challenge is to set it up to sound like my actual speaker cabs do.

One day, I want to make my own impulse responses of my speaker cabs. I want to be able to share them with you, so that you can recreate the signal chain I use for yourself. That’s something I can’t do with any impulse responses that I buy.

I’m going to be using Celestion’s official impulse responses on the CAB M, until I can replace them with my own impulse responses.

Continue reading “Studio Diary #18: Recreating The Sound Of My Speaker Cabs Using Celestion Impulse Responses”

Studio Diary #17: Getting A Better Recorded Guitar Tone By Using Impulse Responses In The Right Place

The whole point of last autumn’s home studio revamp was to get things to the point where I could start recording music again. However, as I mentioned in my 2019 review of the home studio gear, I wasn’t sure I’d got my signal chain order sorted out.

It was a good call.

Continue reading “Studio Diary #17: Getting A Better Recorded Guitar Tone By Using Impulse Responses In The Right Place”

Vintage Celestion G12 Tone Crash Course

Johan Segeborn – the master of tone comparison videos – believes that the speaker is the single most important component in creating vintage guitar tones. He’s put together a whirlwind demonstration of a number of vintage Celestion speakers to show us why.

Speakers are such simple things on the surface, yet – as Johan demonstrates – there’s a lot of variables that make an audible difference. And if you can hear the difference on YouTube, imagine how big the difference is in the room, or in any kind of recording.

Watch the difference to hear how these speakers vary, and then please head over to YouTube to leave a like and a supportive comment.

Initial Thoughts On Celestion Impulse Responses

This is a long read. The whole point of the HomeToneBlog is to go in-depth on getting great guitar at home, and understanding the choices available to us. The backstory is a big part of that process 🙂

I’ve been a very happy Redwirez Big Box user for years now. The sheer amount of cabs, microphones and placement options have allowed me to gradually figure out how everything that comes after the guitar amp affects my tone.

So why am I looking at Celestion’s impulse responses? Well, it’s all thanks to the Kemper …

The Need For Speakers

I’m currently running a dual-amp setup as my pedal platform. I’ve got a pair of Synergy SYN-1 enclosures running into the SYN-5050. I went with a Synergy setup partly for how compact it is … but also because the preamps are interchangeable modules.

Right now, I’ve got 4 different Synergy preamp modules: the Morgan AC, the Metropoulos Metro Plex, Synergy’s 800 and their T-DLX. The Morgan AC and the 800 module both pair well with the T-DLX for pedals. And the Metro Plex is just very special, and worth the price of admission on its own.

As with any amp, these modules need pairing with a suitable speaker to get the best out of them. I could just stick to using impulse responses. IRs are more than good enough for both playing and recording, and they have some serious advantages for home use.

But by getting real speakers – and cabs to put them in – I can mic them up and create my own Kemper profiles. I’ve already made a few, and for me they’re the key to getting what I want from the Kemper.

Choosing Speakers

When it comes to speakers, there’s a lot of choice out there. It’s also quite difficult to figure out how a speaker is going to sound with my amps. How do you describe a speaker tone using words? And how do you account for how a cabinet will influence the sound too?

So I’m playing it safe, and looking at classic speakers that are commonly used with these type of amps.

For the Morgan AC, the advice I was given was unequivocal: a Celestion Blue is the right speaker for that kind of circuit. I’ve also heard good things about the Celestion Gold, so that’s also on the list.

I’ve already got a G12M-65 and a V30. They’ll cover the Metro Plex and 800 modules just fine. I’m not really a big V30 fan, so I’m quite happy to stick that in storage and free up the cab for another speaker. On the forums I hang out on, the Celestion Cream has been getting a lot of love this year. I definitely need to take a close look at it.

That just leaves the T-DLX module. For pedals, I’m running in on the red channel, which is believed to be a Blackface-style circuit. Real Fender Deluxe Reverbs often use Jensen C12K speakers. However, the recent Hot Rod Deluxe MK 4 amps have started using Celestion A-Type speakers, and I’m really enjoying just how good that whole package sounds on the Andertons videos at the moment.

Whatever I choose, I’ll be getting 16 ohm versions of each speaker, and putting them into Victory V112 cabs. I’ve gone with 1×12 cabs because of how convenient they are, and I’ve gone with these particular 1×12 cabs because I’m very happy with the ones I’ve already got. 1×12 cabs are perfect for the kind of tones I’m after.

The nice thing about this whole process is that I can spread the costs out. I can pick up 1×12 cabs 2nd hand when they come up for the right price, and then buy a replacement speaker for it when funds allow. I’m not in any hurry, and the savings from doing it this way will basically pay for one of the cabs and its new speaker too.

I just need to figure out which speakers I want first.

Using IRs To Audition Speakers

Speakers vary quite a bit in price. They’re also physically bulky and heavy enough to be awkward to post if I don’t like them and want to sell them on again. Whatever I buy, I’d really like it to stick, so to speak.

That got me thinking. I’m largely looking at speakers from Celestion. Celestion have started selling impulse responses of their speakers, and those IRs have had favourable reviews. (I believe Brian Wampler uses them for his company’s YouTube demos.) And, to cap it all, Celestion have just launched a couple of bundles – any 3 IRs for a big discount, and any 5 IRs for another big discount.

It’s not going to be a perfect audition. We’re not told what cabs were used by Celestion, but there’s almost certainly going to be a difference. And IRs are a cab-speaker-mic combination. They capture what the mic hears, not what you and I hear. Oh, and I use the Sennheiser e906, which Celestion doesn’t use. So there’s that too.

It’s better than nothing, and – at less than 30 pounds for 5 IRs – it’s a lot cheaper and more convenient than taking a punt on the speakers themselves.

I ordered 1×12 open-cab IRs of the A-Type, Blue, Cream, and Gold to experiment with. I also ordered a 1×12 open-cab G12M-65 to act as a reference tone.  I bought them from the Celestion Plus website.

What Do We Get

After checkout, the first thing I noticed was that there was no download link. I had to wait for the confirmation email to come through to get access to the downloads. That wasn’t a great feeling.

The downloads struck me as a bit weird. Instead of just offering a single ZIP file for each speaker/cab I’d bought, there were also links to download various subsets. I can’t work out the point of going to that trouble. IRs are tiny on disk, and Celestion’s offering is tiny compared to something like the Redwirez Big Box.

My advice: just download the ZIP file that contains everything. That way you’ve got it.

There’s something odd about the ZIP files as well. My Mac couldn’t expand them using Finder. I had to open a terminal and unzip them the old fashioned way, which worked without a hitch. I’d like to see Celestion improve their testing to spot problems like this.

Inside each ZIP file, we get IRs recorded at a number of resolutions from 44.1kHz up, and with durations of 200ms and 500ms. The different resolutions are there to match the audio quality you’re recording at.

The two durations? I’ve no idea, and I haven’t been able to find anything online to help with that. For now, I’m assuming that the 200ms IRs are a lower detail than the 500ms, and that they’re provided for use on machines that don’t have enough CPU to process the 500ms IRs. It’s just a guess.

Celestion have used three classic mics – SM57, R121 and MD421 – plus a TLM107 as a room mic. Each of the main mics have been close mic’d (yay!), and there’s six positions for each mic. These positions have names like ‘bright’, ‘balanced’, and ‘dark’, and they quickly become very natural to work with.

Using The Impulse Responses

I’m using MixIR as my IR plugin in Reaper. It allows me to load and blend IRs in multiple ways. I got it as part of the Redwirez Big Box, and I’m very happy with it.

That ability to blend multiple IRs on a single channel came in very handy.

What I ended up doing was running one of the ‘balanced’ IRs, and blending in a small amount of one of the ‘dark’ IRs to add in a bit more bottom-end. I picked which mic entirely by ear. Sometimes I’d use the same mic for the blended ‘dark’ IR, and sometimes I’d prefer a different one.

It took about an hour to hit on this approach. Once I had it, I found that it worked for me with all the different speaker IRs that I’d bought.

My final track setup was this:

  • track 1: Morgan AC panned 100% left
  • track 2: Morgan AC panned 66% left
  • track 3: room mic IR, panned 90% left
  • track 4: T-DLX panned 100% right
  • track 5: T-DLX panned 66% right
  • track 6: room mic, panned 90% right

Tracks 1-3 use mics from the same speaker. Tracks 4-6 use mics from a different speaker. The room mics are getting a mix of post-FX from the other tracks, plus the result of running those tracks through an Echoplex.

The idea is to build a bigger tone through the effects of audio summing, using the Echolex and room mics to give the sound a bit of life without losing the definition.

And, boy did it work. My pedals have never sounded better.

The Different Speakers

The T-DLX module was the easiest to sort out. I paired it with the A-Type IR and didn’t touch it for the rest of the session.

The A-Type didn’t give me those classic Blackface cleans. It didn’t have the same top-end glassy characteristic. That’s okay. It sounded great with dirt pedals, and I’m sure that I can get more out of this with a bit more time.

The Celestion Blue was a huge step-up in audio quality compared to the equivalent IRs from Redwirez. It exhibited a much wider frequency response. That’s very important with the Morgan AC module, as it is hampered by not having an EL84 power section to shape the tone.

I thought that the Celestion Gold was quite similar to the Blue, only with the highs a little more tamed. I went back and forth between the two, and I found that I preferred the Blue for humbuckers. The Gold – with the way I had the IRs setup – sounded a little dull for humbuckers. One thing I didn’t try at the time: I suspect the Gold may be the better choice for my bright Telecaster.

I did briefly try the Cream with the Morgan AC module. Er … no. That just sounded wrong. I’ll revisit that speaker in another session.

I didn’t try the G12M-65 at all. I wasn’t running any of the Marshall-esque modules, and I was having far too much fun with the Morgan to swap it out.

Great Sound Quality

I ran several of my pedals through the dual amp + Celestion IRs setup, and I was delighted with the results.

I always start with the Uber Bee, as it has become the core of my rhythm tone today. I thought it sounded great with the Redwirez IRs. Through the Celestion IRs, it sounded better still.

From there, I tried a bunch of different stuff. The Fender Pugilist was very happy, especially in serial mode. The Boss BD-2 Blues Driver sounded great. The Lovepedal Amp 11 sounded fantastic, but there again it always does.

The biggest leap though came for my Mad Professor Bluebird Overdrive. Once I had that dialled in, I lost a good hour and a half just jamming along to a backing track made by my friend Dave Page. Lovely thick lead tone that worked perfectly over Dave’s clean Telecaster rhythm work. So happy!

Some pedals didn’t sound so good. That’s to be expected when using an AC-style amp. That’s why I went with a Synergy setup, so that I can switch preamps to suit different pedals.

Conclusions So Far

The Celestion IRs are good. Once I figured out how to approach them, I was able to get better tones than I had from my Redwirez IRs. That was for noodling on a single guitar. I have yet to try them in a mix.

They’ve sold me on buying a Celestion Blue speaker. I am going to revisit the Celestion Gold to see whether it is the better choice with brighter single-coil guitars. I’m not sure that I want both speakers though. We’ll have to see.

I am going to look at whether the A-Type is right for the T-DLX, or whether a C12K would be better for me. I need to stop playing with the dirt pedals, and put some time into those clean tones.

Most of all, I’ve really enjoyed playing through them. Now, if only Celestion did their very own equivalent of the Big Box …

TPS Thoughts On Speakers And Cabs

On this week’s That Pedal Show, Dan and Mick are looking at the effect that different speakers and cabinets can have both on tone and feel.

Everyone focuses on guitars, pedals and amps. Speakers and cabinets are often overlooked, yet they’re such an important part of why your amp sounds (and feels) like it does … and why digital modelling through FRFR speakers doesn’t sound or feel like a real amp in the room.

A great way to get an appreciation for the role that speakers and cabs play is to grab a bunch of impulse responses and experiment.

This video is a great introduction to the topic, in part because they’re not trying to put lots of different speakers into the same cab. They’ve taken the approach of doing what folks do in real life: plugging into different cabs to get different sounds.

Please head over to YouTube to leave a like and a supportive comment if you enjoyed their video.

Suhr Reactive Load Demo

Ola Englund has posted a demo – as only he can – of Suhr’s Reactive Load box, and compared it to the Two Notes Torpedo Reload.

It’s a really cool demo that shows how different load boxes do sound different. Neither one sounds bad. It’s simply a case of choosing the one that you like best.

Please head over to Ola’s channel to leave a like and a supportive comment if you enjoyed Ola’s video.

Fractal Audio X-Load LB-2 Load Box Demo

Burgs has posted a short demo of Fractal Audio’s new? reactive load box, the X-Load LB-2.

This looks a little different to the other reactive load boxes on the market. There’s a voicing switch on the front, to switch between UK and American speakers. Presumably that changes the impedance behaviour?

I’d be interested in putting one of these up against the Captor, to hear how much difference there is in practice. I think that’d be the only way to understand what problem the LB-2 is trying to solve.

Please head over to YouTube to leave a like and a supportive comment if you enjoyed Burgs’ video.

Getting To Grips With The Two Notes Torpedo Captor

Back in January, my wife bought me an 8 ohm Two Notes Torpedo Captor as a birthday present. (It was going to be a Christmas present, but Two Notes can’t make these things fast enough to keep up with demand!) And last week, I added a second one to my rig, to go with my ridiculously-overkill Synergy Amps dual-amp pedal platform setup.

Two Notes Captor on top of an amp
Two Notes Torpedo Captor

What Is It?

The Two Notes Torpedo Captor is both a reactive load box and a fixed-level attenuator. There are three different models available: in 4 ohms, 8 ohms (the one I have) and 16 ohms.

  • As a reactive load box, the Two Notes Torpedo Captor allows you to run your amp without having to have a speaker plugged in at all.
  • The -20db fixed attenuation allows you to turn your amp up to get the power tubes cooking and have a (slightly) quieter volume level coming out of your speaker cabinet.

The Captor is a completely analogue device. Unlike the Torpedo Live or Torpedo Studio, there’s no onboard computer to run impulse responses or power amp simulators. If you want to use it for silent recording, you’ll need to run a plugin in your DAW on your computer.

Why Is It Important?

It’s the first affordable reactive load box to hit the market, that I know of at any rate.

Before this, there was the Suhr Reactive Load (currently £399, twice the price of the Captor) – extra software required! – then the Torpedo range (starting from £560 for the Torpedo Reload and then the Torpedo Live at £680).

That’s a lot of money to spend on a reactive load box for a single amp setup. For a dual-amp setup, you effectively had to budget for a third amp, and then spend that money on a pair of Torpedo units.

Priced at £199, the Captor is a game changer.

Why Is It Useful?

Those of us playing and/or recording at home often want silent recording – the sound of our amp on 10 into our computers, but not coming out of a speaker cabinet at the same time. And that’s where the Captor comes in.

Valve amplifiers need to be connected to a speaker cabinet, so that the signal generated by the output transformer has somewhere to flow to. If you forget to plug your amp into a speaker, you’ll blow the output transformer (if you’re lucky).

A load box like the Captor allows us to run a valve amp without plugging in a speaker cab.

Buy the Captor that matches your amp’s required output impedance, and plug the amp’s speaker out into the Captor. Now you can safely turn your amp on without blowing anything up.

From here, you’ve got a couple of choices on how to get the sound out of the Captor.

As An Attenuator

I originally got the Captor to use as an attenuator.

I’ve been making my own Kemper profiles, and I wanted to crank the amp as much as possible so that the source signal sounded as good as possible. Power tube saturation plays an important role in the overall quality of the tone, and to get it to kick in, you have to turn the Master volume up.

However, my little home project studio The Hermit’s Cave is just an ordinary room in an ordinary house. A cranked amp – especially my Blackstart HT-100 – will wreck my hearing in here. Not to mention the problems inflicted on my family and my neighbours!

That’s where an attenuator comes in.

An attenuator takes the cranked signal from your amp and bleeds some of it off. What comes out the other end is a quieter signal, to save your hearing and your marriage!

More expensive attenuators offer variable power soak levels. The Captor offers a fixed -20db attenuation. To put that in context, that’s roughly the difference between 2 and 4 on the HT-100’s Master volume control.

Which is just enough to get the power tubes cooking nicely.

The end result? A big difference to the quality of the tone captured by the Kemper Profiler – without a louder volume coming out of the speaker cab. There’s more definition to the tone, with the power tubes filling out the mids nicely. And that’s exactly where the Kemper’s internal algorithms seem to work the best.

However, I’m not ready to sell off all my pedals and stick exclusively with the Kemper just yet. Which is where my new Synergy Amps dual-amp setup comes in … along with the Captor’s other useful function.

For Silent Recording

Right now, I’m using a pair of Captors for silent recording.

I’ve just built up a dual-amp setup: a pair of Synergy Amps SYN-1 enclosures, with different modules in each, running into the two channels of the Synergy SYN-5050 power amp. I’m running that in stereo mode, with each channel running out into an 8 ohm Captor.

There’s no speaker cab plugged into either Captor. Instead, I’m using the XLR line out to run a mono signal from each Captor into my Apollo Twin unit. With two Captors, I can run two mono signals, and effectively have a dual-amp setup for blended pedal tones, a la That Pedal Show’s usual setups.

The only noise? The fan on the SYN-5050 power amp, and (if I crank the power amp too much) some sympathetic noise from each Captor. The noise was annoying when I had everything out on top of a speaker cab. For now, I’ve bundled them under a desk and out of the way, and that’s cut down the noise just enough to be able to ignore it – most of the time at any rate.

Both channels at the Apollo run into my DAW (I use Reaper – it’s excellent). There, I record onto two separate channels – one for Channel A, and a different one for Channel B from the SYN-5050. I have different impulse responses loaded onto each channel, chosen to match both the preamp module and the guitar I’m using.

The Captor comes with a license for Two Note’s highly-regarded Wall of Sound (WoS) impulse response plugin. I’m actually using something else – mixIR and the Redwirez BigBox collection.

I’ve been using the Redwirez BigBox for the last 4 years, so I know it well and I’ve had a lot of practice getting the results I want from it. It has great, phase-corrected impulses that suit all the Synergy preamp modules that I’m using. I’m really happy with it.

The end results are excellent.

I found that I got the best results using the XLR output of the Captor, rather than the TRS Line Out. You need to be able to provide phantom power – which the Apollo Twin does.

The Line Out doesn’t need power to operate. I struggled to get a signal that I liked from the Line Out. The output volume there seems to depend on how loud you run your amp. The Captor is rated for 100W amps, and my amp is 50W. Even cranked, I found I was having to crank the preamps on my Apollo Twin too. The end result was too noisy for my tastes.

Your mileage may vary.

What’s The Competition?

The Captor is the entry-level model for Two Note’s Torpedo line of units. There is nothing entry-level about the results you can achieve with it.

On one of the forums I hang out on, someone else posted that the Captor sounds identical to the more expensive Torpedo units. If you don’t need the features of those units – and at home, you probably don’t – then the Captor is an excellent choice.

Almost any other competitor – the Suhr Reactive Load, or Fryette’s Power Station – still relies on impulse responses running in your DAW. You might prefer how these units affect the tone. Each load box uses a different design to bleed off the power, and each design has a different effect on the end tone. We all hear things differently, and which unit you ultimately prefer will be a subjective matter of personal taste.

The only way you’ll get a substantive improvement over what impulse responses offer is to use a proprietary modelling solution like Universal Audio’s OX amp top box. If you want to know more about that, here’s a recent blog post comparing it to the other options.

Final Thoughts

I’ve only just finished wiring up the dual-amp pedal platform. It’ll probably be Easter weekend before I have the time to sit down and really explore what it can do. I’m excited for the possibilities.

There’s no two ways about it. I wouldn’t have been able to build this before the Captor came along.

Because there’s no software running on the Captor – and therefore no software drivers to worry about as time goes on – not only is the Captor cheaper, it should also outlive its more capable big brothers.

If you’re recording at home with valve amps, and you don’t have anywhere to run a real speaker cab at volume, the Captor + impulse responses should be on your list of options.

What Are Impulse Responses?

This question crops up on guitar forums from time to time. I’ve been using IRs for home recording since 2014. They’re great for home recording, where it isn’t always practical to mic up a real cab. And there’s no reason why you can’t use the same setup to listen to your rig when practicing or just noodling at home too.

An IR is an Impulse Response. It’s an audio model of how a reference tone is affected by something. They’re commonly used to emulate what a guitar cab, speaker, microphone setup does to the audio signal from a guitar amp.

There’s several different ways you can run IRs:

  • pedals, such as the Two Notes Le Cab
  • outboard gear, such as the Two Notes Torpedo line
  • plugin in your recording software on the computer

I run them on the computer. Just personal preference. I’m reluctant to spend that kind of money on outboard gear that has a limited shelf life. Even if the gear itself still works, at some point they’ll stop making new operating system drivers for the unit.

To get the guitar amp signal into the computer, you need a load box of some kind. The load box connects to the speaker out of your amp, and then runs into your audio interface as a line-level signal. Without a load box, you will blow the output transformers on your amp (if you’re lucky). You need a load box that matches your speaker out – 4 ohms, 8 ohms or 16 ohms.

There’s quite a few load boxes on the market these days. ‘Reactive’ load boxes are considered the best type to get. Instead of a single load, they vary the load, mimicing the way a real speaker fluctuates as you play. You can get standalone reactive load boxes like the Two Notes Captor, or outboard gear that’s both a load box and IR player all in one.

You can do other cool things with IRs too. I have a set of impulse responses that model different venues – for example, the sound of a theatre or (my favourite) a famous neolithic burial chamber. I use them in my mixes to add life and room ambience, without needing expensive outboard gear or CPU-intensive plugins.

Final thing to know about IRs is that they’re an audio snapshot. They capture what happened to a reference signal at that point in time. There’s nothing active or dynamic about them at all. You don’t edit an IR if you don’t like it – you switch to a different IR instead.

That’s why Universal Audio’s OX unit is getting so much interest, because it uses active software models rather than IRs. It should be indistinguishable from a real cab, speaker and mic – as long as you like the cabs, speakers and mics that they’ve chosen to model. IRs offer a lot more choice, at the expense of being static models.

You can purchase IRs direct from speaker manufacturers like Celestion (haven’t used them myself, heard rave things about them), or from third parties like Ownhammer or Redwirez. If you’re just starting out, and you’ve no experience micing up real amps with real microphones, I recommend buying a bundle like the Redwirez Big Box (not affiliated, just a happy customer). A bundle gives you a lot more options to explore, allowing you to experiment and figure out which cabs, mics, and mic positions you prefer.

If you’re looking for silent playing and/or recording at home, it’s hard to beat a good load box and a set of impulse responses for the money. You can get great tone, and keep the family and your neighbours happy, all at the same time.