Front vs Rear Loaded - Guitar Cab Test Engineering

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In this video I try to find out if there is a difference between front loading a speaker cab and rear loading a speaker cab.
Download the REW sweeps and reamped riffs here for your own analysis:
www.dropbox.co...
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Timestamps:
00:44 Intro
02:57 The plan
03:18 The main challenge of this test
05:13 Kreative Devices
06:15 Test setup
08:20 The Analysis
Gear and tools used:
Harley Benton G412plus
Various Celestion Vintage 30s. The closed mic'd one was from 2003. All 8 Ohms
A Shure SM57 for close micing
A Beyerdynamic M160 for room sounds
Lichtlaerm Audio Prometheus for guitar sounds and its power amp for REW sweeps
Radial reamp box
Rupert Neve 511 500 series preamp module in a Fredenstein Bento 6 (SM57 only)
Audient ID44 mk2 preamp (M160 only) and converters (both mics)
Room EQ Wizard
Reaper
Voxengo SPAN Plus
Nugen Audio AB Assist 2
OBS Studio

[@TheOtherJohnBrowne]

So, what do you think? Do you agree with my assessment or do you think I'm wrong? Download the REW files and riff recordings here for your own analysis: www.dropbox.com/scl/fo/dk0shvls1iyzjdnl01n1o/AHJbYKJWtqteScEFEnWmpz8?rlkey=4en6i3295tekp9tole45s60st&st=za0e0udo&dl=0 If you want to support me, using my affiliate links is a great way: Thomann affiliate: www.thomann.de/de/index.html?offid=1&affid=3394 Tube Amp Doctor www.tubeampdoctor.com/celestion-g12tad-30-30th-anniversary-12-30w-8-ohm-made-in-uk?sPartner=TOJB

[@JohnnySilverhand-k3u]

There is obviously a difference in the sample at the start.. But now I have to see the rest... 'plus would it change it live or in studio or with the mics positioning 😅

[@citizen_d]

A sounds open/neutral, B/C are more pumped with the "A"-mids, as if you are talking right in front of your hands.

[@K707OR30]

Dude your self-deprecating intros are the best, worth watching just for those alone. Alright going to continue actually watching the video now.

[@TheOtherJohnBrowne]

Cheers, man! I appreciate it!

[@anttihuovilainen1653]

Coming from academic background in audio and acoustics, it's great to see someone do proper tests when it comes to guitar sound. Huge props for making an effort at eliminating obvious confounding factors like distance and volume difference. Your tests are miles better than what others show on youtube.

[@TheOtherJohnBrowne]

Thank you! That means a lot to me

[@Zwidawurzn]

Man, you are doing all the stuff i'm not brave enough for.

[@ollisarala]

I am not an expert on this topic, but I see a couple of variables that could change the response in this case. First off, the front-loaded configuration has a slightly larger internal volume. As the cabinet is on the smaller side, the lost volume could have a more pronounced effect. Second, the gasket on the speakers is much thicker on the front side (at least in the ones I have) and could result in different amount of warping in the speaker's frame (and the cone) when you tighten it in the rear-loaded configuration. Third, you could see some cancellations due to internal reflections since the speaker cone's distance from the back wall changes between the mounting positions. The last thing that comes to mind is the baffle diffraction. It should be more present in the rear-mounted configuration, but I don't think you could measure it in the close mic position.

[@RX120D]

Hey, John. Thanks for all the great videos and the IRs you provide.

[@TheOtherJohnBrowne]

Glad you like them!

[@roberthastings708]

Very good. Thank you. I expected little difference. I often swap drivers, so front loaded is usually more convenient for me. Pragmatic of me I know. I expected some high frequency variations due to the defraction introduced by rear loading.

[@mikejackson7880]

The front loaded sounds less muddy to my ears, but they're both very usable. And I love the KD logo on your laptop, I want one for mine!

[@lordgraga]

Great work. You’re setting new standards mare.

[@TheOtherJohnBrowne]

Much appreciated! That'd high praise

[@springsgaming7551]

Interesting mostly because the room sound was so darn close. I feel cab design matters more at which speaker loading might be a preference technique for building more so. That’s my take on what I learned here but for sure I was curious. Appreciate your videos always John!

[@PippPriss]

I am also a clumsy idiot. I often bump into stuff. In my case, I bump into awesome videos like this one. Well executed, awesome stuff! Thanks again and happy new year to you!

[@TheOtherJohnBrowne]

HNY to you too, bud!

[@flachmann161]

Great video! And yeah, as Kristian also saw/heard, there isn't a noteworthy difference between front- and rearloaded cabs

[@Jazzguitar00]

I'm glad we got a different riff today. We did it.

[@TheOtherJohnBrowne]

Hahahaha! I know, right? Yeah, I actually had some time to play guitar just recreationally over Christmas and was able to come up with a few new ones

[@jenyahp2828]

YES! Dude. It's like you are reading my mind. The SM57 with the rear loaded speaker is soooo much more focused. Its crazy. And the front loaded 2nd option (with the distance) is also different. It sounds more honky (the mids are somehow shifted (in comparison to the rear loaded one). In the room the differences are very low. As expected. But "C" (I think its the rear loaded) sounds more balanced. I watched the video. Got back to the graphs and it all makes sense now. Thank you John!

[@TheOtherJohnBrowne]

Yes! C was the rear loaded cab. I'll be uploading the recordings and graphs and sharing in the video description and pinned comment later

[@JoelGrindMusic]

That jig is sweet, i have a dynamount robot stand but that would come in handy for a second mic.

[@TheOtherJohnBrowne]

Yeah! It's my ghetto, manual Dynamount

[@arronsondrini380]

@@TheOtherJohnBrowneplan on building one myself now, thanks for the idea :) those dyna mounts aren’t cheap lol

[@EBcobhc81]

Wow! That is crazy. I would have thought the sound was drastically different. I did hear the slight differences you explained, but nothing that couldnt be adjusted with eq. I definitely agree with you. Nice video!

[@TheOtherJohnBrowne]

Thanks for watching!

[@blasher4]

Love the content man. I always look forward to it.

[@TheOtherJohnBrowne]

I appreciate that!

[@blasher4]

@@TheOtherJohnBrowne My pleasure. As you know, pickups are important part of tone in an electric guitar. I've also noticed a difference in sound between 250K and 500K pots as well as types of capacitors. The sound isn't as wildly different than let's say changing speakers out, but the differences are there. I would love to see some EQ curve differences between electronics installed in the same guitar. Sounds nerdy but fun!

[@franzkindermann434]

Thanks for putting so much effort into comparing front vs backloaded cabs. I also saw Christian Kohle's vid and it seems (didn't try yet), the differences in close miked recordings isn't that dramatic. But I could tell a difference in sound pressure and general more "oomph" in the room during rehearsals with the band, moving from a front- to backloaded configuration. It feels like more weight in the room on a lower amp volume setting and dialing out a little bass eq. I think, for close miking rock/metal guitars, it does not make a a huge difference. Rather moving speakers from a 1x12 into a 4x12 cab makes a way more drastic sound shift.

[@SimonHosford]

John, I just LOVE your channel so much, and LOVE how empirical your tests always are, unlike many other channels.. but also your explanations are concise and sound, and I love listening to you talk. Thanks for all your many many hours of laborious work and attention to detail. On behalf of all of us curious tone chasers all over the world, HAPPY NEW YEAR, and all the best from Melbourne Australia. Best, Simon Hosford 🤟🙏

[@TheOtherJohnBrowne]

Thank you, Simon! I really appreciate the comment a lot. Happy new year to you too!

[@guvnafied]

Really good video John. I used to run a fantastic sounding Laney oversized 2x12 slant cab from the 1980s which was one of the warmest cabs I've played, and only recently when looking at photos did I realise it was front loading. It really doesn't seem to make any real difference except for the ease of changing speakers, and even then one could argue its no easier if you have to desolder wires.

[@j4q0]

Finally! Thank you! Your channel is trully a gem.

[@TheOtherJohnBrowne]

Thank you!

[@MaxPowersTastyTones]

Great video as always 🔥

[@TheOtherJohnBrowne]

Thanks, mate

[@MartinKrappitz]

Really interesting, tnx John B!! To my memory the diezel guys described their FL-cabs as being kind of more "direct" than RL... hard to tell from here but had back in the day a (german made)FL diezel cab 412 with V30 and K100 mix in X pattern and consider it as one of the best (or even THE best) cabs i ever had/heard. Silly me sold it 😵‍💫 Should chase one again 😂 (Btw- sending you my blueface vh4 for a detailed check and comparison with a new silver one would be the right thing to do, guess u would know how to do this proper, let me know !)

[@TheOtherJohnBrowne]

Whoa! Seriously? You'd let me borrow a blue face VH4?

[@BlackReaperMetal]

The best way I could describe it is like the same dude singing with the only difference being how much they open their mouth. Rear loaded sounded more closed mouth, while front loaded sounded like a wider gape where you can see the teeth. Same sound signature though. Thank you for your work.

[@TheOtherJohnBrowne]

Nice analogy

I loved the comparision thank you very much!

[@EDWINPIERCE168]

The intros need an intro. Best reviews online. Playing sounds good too. 😊

[@TheOtherJohnBrowne]

Thaaaank yoooouu

[@zanthraxus]

Happy New Year and thanks for chasing down another rabbithole for us! Got a rear loaded cab back then based on some half baked notions. Now though the differences don't seem drastic - I can't help but wonder how that would affect the setup. Cheers for another great video!

[@TheOtherJohnBrowne]

Happy new year, buddy!

[@KreativeDevices]

🔥 One of your best yet

[@TheOtherJohnBrowne]

Thanks man! Powered by KreativeDevices

[@KreativeDevices]

@TheOtherJohnBrowne 🙏

[@DerSilvano]

Fantastic video idea, John Keep up the good work

[@TheOtherJohnBrowne]

Many thanks!

[@TheGooseChaseMusic]

Loved this, lots of conclusions to draw, including one I was thinking as I listened: maybe the differences are small enough that I'd opt for whichever is easier to swap speakers with.

[@TheOtherJohnBrowne]

Thanks, buddy! Yeah, or whichever one I can find the better deal on

[@DennisL-n6i]

A the front loaded is brighter withmore static highs or fizz. The rear loaded the red those are louder everywhere and crunchier and clear highs.😊

[@Waycooljr5]

@TheotherJohnBrowne you know it would be cool to settle this debate forever if MDF versus Birch makes a difference in the quality of a cabinet as far as sound

[@TheOtherJohnBrowne]

It's another rabbit hole I'd like to go down for sure

[@tgchan]

Johan Segeborn, has done it. You can check it out in the meanwhile/

[@Waycooljr5]

@ can you send me a link?

[@NeZversSounds]

That HB cab looks like it has parallel front and back walls. My guess is that angled walls or open back could reduce the difference even further. You can add that to your rabbit hole content :D

[@krailanuar]

Thanks for nice video TOJB

[@TheOtherJohnBrowne]

Cheers

[@s.d.howarth8268]

A few strips of masking tape, chalk marker, or a jig with feet positions would tick off ease of setup in terms of distance to cab for consistency, or future comparisons. Interesting stuff - cheers.

[@rigorhead01]

I'm certainly no expert, but I've reconed a few speakers. The cone is glued to the frame of the speaker, covered with a layer of cork-type material. Rear loading the speaker will prevent the cone from becoming unglued from the frame, because it's being sandwiched between the frame and baffle. Just some random thoughts on the issue.

[@Greg25815]

Good job man. Interesting !

[@TheXxPSYCHO]

Grill vs no grill next!

[@stegerguitars]

Awesome! thanx....Now i won't lose any sleep about inside mounting my 12's in my custom made by me cab. yer not a freakin idiot....not completely....

[@aheadofmetal]

can you link some info on what you used to make the sliding rig? seems like a very helpful tool.

[@TheOtherJohnBrowne]

It's just a Neewer 800 mm slider on a mic stand/tripod with some cheap amazon camera slider on top of it as well as some Manfrotto knock off quick release plates and some thread adapters

[@aheadofmetal]

@@TheOtherJohnBrowne sweet. Looks like a much more precise solution rather than boom stands. Mine always move and get bumped around

[@christophgrubor7365]

Thanks again, for all your effort!🙏 It is interesting how your video and the one Christian Kohle did come to the conclusion, that rear vs front loading doesn't really matter. We might be splitting hairs, here. But, it has been a debate for ages. Maybe the effect in feel, by standing directly to the cabs and playing has more effect on the player, than the more producer-like miking it up situation. That would be interesting hear. In the end, the performance matters, that's what producers say a lot. So, that being said, the feel the guitarrist might have effects the playing and has different results. Human factor, music and art in general is all about the human factor. What makes me wonder is that the rear loaded version is louder, actually...

[@TheOtherJohnBrowne]

Cheers mate! Well put. It's the performance that matters

[@SonicDriveStudio]

Awesome! Front loaded ftw, always loved that growl! Great video dude!

[@TheOtherJohnBrowne]

My guy! ❤️

[@dylanjastle]

Sounds pretty good through my phone speakers

[@Greg-ht2uv]

Thanks for doing the leg work on this experiment, very interesting. I think rear vs front is one less variable to really concern myself with. Question though.. when doing the analysis graphically can you subtract the graphs to simply show the differences? It may make the differences standout more obviously. Or likewise when comparing them sonically, polarity flip one track and then subtract the two?

[@TheOtherJohnBrowne]

Brilliant comment. I'll look into that. In fact, I'll upload the files to dropbox and share them with the community

[@JD-kj4mj]

Yes great comment, I second this! But I'd add that this will only be accurate if mic distance to the cone is precisely maintained and you use the interference technique to perfectly center the mic. The other difference you can hear is phase shifts between frequencies where as a sweep response graph does not detect this.

[@Greg-ht2uv]

@@TheOtherJohnBrowne thanks for all you do! Re-reading my comment .. I didn’t intend to ask for more analysis (I apologize for the poor wording). As I’ve been watching all the in depth analysis you perform , I often wondered if a difference plot would be helpful to makes differences stand out immediately. Not sure that is something the in room IR software supports though. Cheers!

[@oskarwroniewicz]

I think the polarity flip may not work with 100% accuracy in this case. Speakers are not perfectly linear like digital signals are - after all they are moving air, not producing the same 1s and 0s each time you play the same audio. Same goes for a tube power amp, which even though it's "clean", it's reproduction also ain't as perfect and consistent as digital. If you play through a distorted preamp too, the accuracy of a null test would be even worse I imagine. So even if you played exactly the same audio twice through exactly the same setup and flipped the phase on one, they wouldn't cancel out perfectly. At least that's my thesis, but it would be interesting to put it to the test

[@JD-kj4mj]

@oskarwroniewicz It actually works very well. We do these tests routinely in my field. The only thing I'd caution is that a frequency response graph is only part of what you hear. Instruments have a fundamental and harmonics for a given note that make it's timber. Now imagine (for simplicity) that a speaker inverts one harmonic with respect to the fundamental but the amplitude of every harmonic stays the same. Every harmonic will have the same amplitude but the full frequency waveform will look and sound different as one harmonic is mathematically inverted. So again, a frequency response graph does not capture this but your ears certainly do.

[@geronimostade8279]

Speaking only of the one Mic close to the cone i tend to say that the SPL gain could be explained - perhaps - via the small baffle frame / thickness, which may have sort of beam forming properties in a rear loaded config. And this may also explain that the interaction in front of the cabinet is different due to other phasing properties over a front loaded cab.

[@geronimostade8279]

By relistening i can underline this by my thinking that the rearloaded sounds less phased than the front loaded - but that could just be my ears. Scientifically it would be acutally interesting how this would have turned out in a 1x12 cabient. I know for a fact that the distance between speakers makes all the difference in the world (in front of the cab) - not saying that i have a perference of speaker distance...

[@millermonsterair]

i FINALLY got myself a 4x12 cab the other day. its just a Marshall AVT412 4x12 cab with the stock AVT celestion 12in speakers in it, but i dont hate it so far. i am going to change out the speakers with something else, so here i am on this channel learning what combo of speakers i will like in it. who knows, i may disconnect the bottom two speakers and just use it as a 2x12, but who even knows at this point. lol

[@TheOtherJohnBrowne]

Sweet! Happy new cab day!

[@NacekO]

Awesome video. Judging by this, I think it's noithing to worry about when buying a cab.

[@TheOtherJohnBrowne]

I'd be inclined to agree

[@NacekO]

@@TheOtherJohnBrowne and so does mr. Kohle by the looks of it. He also got similar results. Minor differences.

[@drrodopszin]

If you feel you're always bumping into things maybe you wanna look up dyspraxia. Speaking of the real topic of the video I thought that I wouldn't hear any difference but they were indeed different, different enough that I would consistently reach for one over the other when dialing in the cab tone. I've oddly preferred in the tests version C (back-loaded) even compared to version B (front-loaded, matched distance). The difference was somehow manifested for me in density and distance. One started to get honkier than the other.

[@K707OR30]

I agree, pretty negligible difference. Could possibly be advantageous to play around with front/rear loading in a “in the room” context for your ears to tame or accentuate some frequencies, but yeah nothing crazy. I think the best application of this is really for quick/easy speaker swaps over big tonal differences.

[@TheOtherJohnBrowne]

100%

[@K707OR30]

@@TheOtherJohnBrowneif you do end up doing a front loaded for that reason, not sure if it even exists but find one that has threaded inserts and machine screws for mounting speakers. Wood screws as I’m sure you’ve already found out will bore out the mounting holes to nothing after so many uses, which really isn’t that many.

[@AlanW]

Amazing job, I can't think of anything that could have been done better. I don't suppose you've seen Segeborne's distance micing comparison video? I found it almost as interesting as your comparisons!

[@TheOtherJohnBrowne]

Thank you! Yes, I have. I am a Johan Segeborn fan

[@HeirApparent]

I'm somewhat surprised... the rear loading simply sounds better mic'd

[@eoinc_Ire]

Is it the fact that the 18mm ( or what ever the baffle thickness is) is hindering the vibration of the top of the speaker on the front loaded speakers? Where the back loaded are free from any interference. There could be some sort of wave form reverb bouncing between the 18mm of cone and baffle, cancelling out some of the frequencies??

[@veers0r]

Really well done, as always. Do you remember how much you shifted the microphone to compensate for the speaker position? Would be interesting if the shift in frequencies around 550 Hz and 1.1k (As seen at ~12:00 ) match up with that. :)

[@TheOtherJohnBrowne]

24 mm further back

[@TheOtherJohnBrowne]

And thank you

[@veers0r]

@@TheOtherJohnBrowne Interesting, so assuming the blue/front dip is at 550 Hz that distance would be about 620 mm, at least plausible for twice the distance from the back to the cone to the back of the cab. Subtract 2 * 24 mm for the rear. 572mm would land at 600 Hz. Graph looks more like it's just shifted to 575 Hz. That requires a bit too much squinting to check out so I guess my calculation is too naive. :)

[@veers0r]

I think I found my mistake. The frequency axis is on a log scale, so it's not 550 and 575 but more like 520 and 550 which then roughly checks out (620 mm vs 660 mm).

[@scharrface]

Do you find that the front loaded configuration "fills the room" more? I haven't experimented with rear/ front loading the same cab, but feel like my front loaded cabs have a wider dispersion of sound, so that they sound more consistent when you stand in different positions in the room, where in general I've found my rear loaded cabs to be more directional in that if you're not standing right in front of them, they sound much darker

[@TheOtherJohnBrowne]

I can't really say I noticed a big difference in the room. At the same time, I wasn't listening for that actively

[@jeffseven2194]

My Sound City cabs are front loading n my Marshall cabs are rear loading. I think the Sound City cabs have a little tighter low mid

[@Paul_Lenard_Ewing]

The volume of the cab is changed by the more mass from the speaker being out or inside. Or the cab will resonate differently and one will have more Thud than the other. Once again the bottom line is ascetic. One will sound more open and the other tighter.

[@pastorkev777]

Quite close in my opinion, I prefer rear loaded by a hair, but will not make cab decisions by this factor. I feel the frobt loaded has a bit more upper mid, slightly more hollowed out, and rear is just a tad more even. It is really not a deal breaker either way.

[@samuelsmith4494]

What mic(s) and positions were used for the intro A/B that is videoed from off to the side? I personally prefer the front load sound based on that perspective (whatever it was).

[@TheOtherJohnBrowne]

Those were all SM57 samples. I think the first front loaded sample was with the mic closer to the speaker iirc

[@kingpriapatius5832]

I've mainly used front-loaded cabinets. However, based on your video and Kohle's, the rear-loaded cab might be easier to mix. But again, the difference is not big.

[@TheOtherJohnBrowne]

I agree!

[@minecraftyeled7889]

A high gain amp through a y2k v30 recorded on a 57 should be dubbed the browne sound.....

[@dougleydorite]

Your pads wearing out like that will impact the sound of your headphones massively. I highly recommend changing them and only use OEM

[@Frankentoane]

You must be paying royalties to Devin and receiving commish on wish.loljkk😂

[@nikolas_navarro]

In summary, it does make a little bit of a difference, technically, but in the context of a mix you'd be hard pressed to find it.

[@TheOtherJohnBrowne]

Well put

[@CoolGuyAtlas]

The context of a mix is worthless because a 6” speaker with some EQ can work in a mix. Drums and bass also vary a lot, so really you can make anything into a mix. We shouldn’t compromise every step of the way on tone, nor should we pretend like measurable differences are negligible. We aren’t CEOs trying to make deadlines under budget. We are artists and guitar nerds. If we don’t care, who will?

[@MelodiosoX]

At 17:39, is A = Front Loaded and C = Rear Loaded ? C seems to sound more "boxy" compared to A, which is why I preferred A in this section. But nothing drastic which couldn't be fixed by an EQ afterwards.

[@TheOtherJohnBrowne]

Correct

[@djabthrash]

13:43 My biggest takeaway from this video is actually that Nugen Audio "AB Assist 2" plugin you were using in Reaper to A/B/C things ! Brilliant utility plugin ! : kzbin.info/www/bejne/qn-rhHqPbJplfZo

[@TheOtherJohnBrowne]

It's a fantastic tool

[@djabthrash]

@@TheOtherJohnBrowne Just bought it after watching your video, can't wait to use it :)

[@ArtEntity]

How long will it take till i become a good guitar player !?!?!!?! 😢😢😢😢😢😭😭😭

[@TheOtherJohnBrowne]

No idea. 20 years in and I'm still hoping it will happen to me

[@bigmike9527]

Dude you talk to much,the average player just wants to hear the difference

[@TheOtherJohnBrowne]

@@bigmike9527 that's why there is a section with the sounds just seconds into the video, dude. Also, there are chapters in the description to help you navigate

[@catalyzed8457]

@@TheOtherJohnBrowneDude. Thanks! 😂

[@MachenSS666]

I see you possess a Peavey 3120.....As do l....great amp..