Dual Cab block vs 2 separate cabs - otherwise identical settings - not identical result

[bsd512]

I've been a pretty hard-core IR guy for a long time but recently started using stock cabs (because HX Edit was late at Stomp release and I was forced to use stock cabs).

 

Long story short - I now love stock cabs, I just wasn't very good at making good cab and mic choices.

 

This leads me to a strange situation I encountered.

 

If you make a preset with an amp (not amp+cab) - put two cabs after it in a split path then merge immediately after the cabs. Follow that by anything else (delay, reverb, whatever - might need to be stereo, not sure).

 

Then if you copy that preset exactly. Delete the two stock cabs and replace them with a single dual-cab block. In the dual cab block, duplicate exactly the settings you have in the two separate cabs in the original preset.

 

You might need to lower the pseudo-merge block in the original preset by about 2db to account for the volume difference.

 

Now A/B those two presets using headphones so you can hear the nuance.

 

Should those two presets produce identical results?

 

I'm 100% convinced they are different. Should they be the same?

 

[bsd512]

Following up ... I recreated this in Logic Pro X with two instances of Native, one with two separate cabs, the other with a single Dual cab.

 

With the two separate cab version, the output is evenly balanced feeding into a stereo delay and stereo reverb between the left and right channels.

 

With a single dual cab with two identical cabinet settings, the left output channel is slightly higher than the right channel - which is what my ears were hearing. Flipping the polarity of one of the instances, resulted in incomplete cancellations. It was a lot quieter, but they did not completely cancel.

 

If I sum both instances to mono - I can get the inverted polarity a LOT quieter, but not to completely cancel.

 

I'm assuming this might be because a Dual Cab outputs in mono? While a split path with a cab in each path is ultimately recombined and merged in stereo?

 

But still - why would one side of the stereo path have slightly more gain than the other for a dual-cab block which outputs in mono than for a split-path+2 cabs that outputs in stereo?

 

The dual cab block is driving my ears nuts whereas a split path w/cab in each path is perfectly fine.

 

What gives?

 

Any advice appreciated? I'd open a support ticket, but this seems like it might be really hard to explain in a ticket.

[PeterHamm]

Dual cab outputs in stereo. don't know why you're experiencing this. I've had GREAT luck with Dual cab, but have never tried this test, I think I just might do this experiment when I get a chance.

[dragonfet]

Which firmware version are you using? I will try to reproduce this.

[bsd512]

2.7

[bsd512]

Here's a screen shot showing both instances up in Native. The one on the right is the Dual Cab, where the one on the left is separate single cabs on a split path.

 

Note the stereo levels on the right - the right channel (sorry, I said left before) is slightly higher than that of the left channel.

 

The input to these Native instances is the Logic Pro X "Test Oscillator" so that the signal is nice and pure and unvarying so that the output is stable.

 

Just eyeballing the rather coarse output meter in the Native Instance, the Dual Cab right channel looks to be about 4 dB higher than the same cab on the split path version.

[bsd512]

Here are the presets pulled out of Native Incase someone can double check me and make sure I didn't do something the cause this that I didn't notice. I40 is the Dual Cab. 2xI40 is the split path version.

 

Archon I40.hlx

Archon 2xI40.hlx

[amsdenj]

It's possible that Line6 is phase aligning the cabinets in the dual cabinet block, but they are not exactly phase aligned when in separate blocks. You should be able to see this in Logic.

[Lachdanan0121]

20 minutes ago, amsdenj said:

It's possible that Line6 is phase aligning the cabinets in the dual cabinet block, but they are not exactly phase aligned when in separate blocks. You should be able to see this in Logic.

 You know I have been thinking. 

 

I have seen your posts before quite a few times on here, and you are pretty damn knowledgeable. So I figured I would run this by you.

 

What about a setting/parameter in the cab blocks, and IR blocks of course,  that allows for manual adjustment phase alignment.  A knob/slider that allows you to set the offset in the cabs so you can blend the phase how you like?  

 

Is this a far-fetched idea? I assume it could be implemented to where people who don't want to mess with it won't ever have to touch it, and thus not mess up previous presets. I am not sure how much of a programming job that would be, but it would really allow for some surgical editing. 

 

 

Don't mean to steal thread, But it may be relevant.

[bsd512]

1 hour ago, amsdenj said:

It's possible that Line6 is phase aligning the cabinets in the dual cabinet block, but they are not exactly phase aligned when in separate blocks. You should be able to see this in Logic.

I looked at checking phase alignment - I didn't know how to do that for the left and right side of a stereo output.

 

However - I think I have an answer for what is happening. Unfortunately, I think the answer means that the dual cab block is not useful to me.

 

amsdenj's suggestion got me looking closely in Logic and Native.

 

The difference between the dual cab block and putting two cabinets on a split path - all cabinets with identical settings is how those cabinets are panned left and right (or not).

 

The dual cab block pans one cabinet far left, and the other cabinet far right. You can do that in a split path, but in my preset above with the split path and separate cabinets, I had the merge block to center them. If instead I pan one of the cabinets at the merge block all the way to the left and the other all the way to the right, I can reproduce the exact behavior of the dual-cab block.

 

So that mystery is solved.

 

But what the heck - the dual-cab block really needs a pan dial for each cabinet. What I'm trying to do is simulate a dual-mic'd cabinet coming down the center, not panning two totally different sounds panned hard left and hard right.

 

I find it hard to imagine that this behavior is what Line 6 intended with no flexibility to mix those cabinets either fully (centered) or partially to the left and partially to the right, versus being fixed at hard-left and hard-right.

 

Thoughts?

 

Note - this isn't a huge problem for Helix and Native - we have plenty of blocks to spare. But I also have a Stomp and blocks are a lot more precious in that box which only has 6. I'd like to get one back by using a dual cabinet. But the sound I'm after is way off vs the split approach. Not to mention dual cabinets would be a lot more flexible if each cabinet could be panned. If so, this thread wouldn't exist. :-)

[bsd512]

One more quick follow-up ...

 

Using a single cab and a single mic from the stock cab inventory, I can still get great results. So in no way is this the end of the world or anything. I was mainly surprised that the Dual Cab block worked the way it did - panning on cab hard left and the other hard right. And fixed that way with no option to vary them.

 

And what I was trying to do was to mix a dark mic with a bright mic to get a nice full range - the smooth fullness of a ribbon and the brightness and bite of a dynamic. And use that as if it was a single cabinet mic'd with two very different mics. So it was my own misunderstanding of how the dual-cab block works that led to the above.

 

I mentioned I'd been using IRs for years - mainly because I had trouble with the stock cabs early one, multiple people suggested IRs, I tried a few - they were great, and I stuck with them ever since.

 

But now after a couple of years of experience using IRs, I know a lot more than I did about mics, speakers, and cabinets - more than I ever thought I would or needed to. But with the release of the Stomp without HX Edit, I was forced to use stock cabs since there was no way to use IRs. But in doing so, and with the couple of years of using IRs under my belt (I could dive into an OwnHammer pack and pick the 3 IRs I wanted out of 700 in about 30 seconds), I found it a 1000 times easier to set up the stock cabs to my liking.

 

So thanks to HX Edit being late to release for the Stomp, I'm a convert. I'm now a stock-cab guy. Stock cabs rock! So I'd like to extend a personal thank you to Line 6 for NOT releasing HX Edit at the same time as the Stomp. If they did, I would have certainly loaded up all my IRs and gone on with status quo.

 

As it is ... now that I've "discovered" stock cabs and their awesomeness, it's like I got a whole new Helix Update that now includes great stock cabs. :-) (Education and experience are a wonderful things!)

 

On this whole dual cab behavior thing - yes, it would be great if L6 might include pan knobs for each cabinet so you can vary their contribution a bit easier and not have to pan them fully left and fully right. But I'm still getting great tones and results from single cabs - now that I have more experience with that - ironically, from using IRs for several years.

 

Why didn't anyone ever tell me stock cabs were so awesome?! Ok, yes, I've heard that many times on this forum but dismissed it because I thought I knew more than I really did. :-)

 

Anyway, I can get really close to that dual cab sound using a couple of the mics available - some might need a bit more or less hi-cut, and maybe an amp tone knob trim or two, but this really is not a big problem. I'll call it a nice to have - and the computer scientist in me says the panning capability should be there for completeness and not fixed at hard L and R.

 

Also - one big advantage of using a single cab with the Stomp is that you can simply use the Amp+Cab block which frees up yet another block. So where I might use the split method before, that frees up 2 blocks. And if I used the dual cab to get that mic-mix sound, it frees up 1 block.

 

So all's good. Great even.

 

Final word - the dual cab block still needs pan knobs for the cabs. It just seems like an oversight. :-)

[marmatkat]

@bsd512 Thanks very much for the info. I've been a Helix owner for a few years now, and I get good tones, but I've been avoiding playing around much with cabs, and with the stock cab settings (esp. mic choice, etc.) Given your experience bringing your IR knowledge to the stock cabs, would you be willing to share any guidelines/principles you've discovered? Even a few general pointers would be awesome, like mixing cabs with different mics, maybe a handful of mics to start with (and applications), etc. Apologies for the vague question, and for not having looked around the forum much. Either way, thanks again!

[arislaf]

22 minutes ago, marmatkat said:

@bsd512 Thanks very much for the info. I've been a Helix owner for a few years now, and I get good tones, but I've been avoiding playing around much with cabs, and with the stock cab settings (esp. mic choice, etc.) Given your experience bringing your IR knowledge to the stock cabs, would you be willing to share any guidelines/principles you've discovered? Even a few general pointers would be awesome, like mixing cabs with different mics, maybe a handful of mics to start with (and applications), etc. Apologies for the vague question, and for not having looked around the forum much. Either way, thanks again!

You can get my presets on the 

 

And reverse engineer them to fully understand them.

 

[arislaf]

2 hours ago, marmatkat said:

@bsd512 Thanks very much for the info. I've been a Helix owner for a few years now, and I get good tones, but I've been avoiding playing around much with cabs, and with the stock cab settings (esp. mic choice, etc.) Given your experience bringing your IR knowledge to the stock cabs, would you be willing to share any guidelines/principles you've discovered? Even a few general pointers would be awesome, like mixing cabs with different mics, maybe a handful of mics to start with (and applications), etc. Apologies for the vague question, and for not having looked around the forum much. Either way, thanks again!

As well as read some of these https://www.thegearpage.net/board/index.php?threads/helix-stock-cabs-ideas.2038915/

[craiganderton]

On 10/21/2018 at 11:57 AM, bsd512 said:

I find it hard to imagine that this behavior is what Line 6 intended with no flexibility to mix those cabinets either fully (centered) or partially to the left and partially to the right, versus being fixed at hard-left and hard-right.

 

Thoughts? 

 

You can do both - place a Stereo Vol block after the dual cab, and choose the Stereo Width option. Varying Width changes the cabs from centered when fully to the left, to full stereo when set to the right. In between those extremes gives partial panning. Hope this helps!

[bsd512]

6 hours ago, marmatkat said:

@bsd512 Thanks very much for the info. I've been a Helix owner for a few years now, and I get good tones, but I've been avoiding playing around much with cabs, and with the stock cab settings (esp. mic choice, etc.) Given your experience bringing your IR knowledge to the stock cabs, would you be willing to share any guidelines/principles you've discovered? Even a few general pointers would be awesome, like mixing cabs with different mics, maybe a handful of mics to start with (and applications), etc. Apologies for the vague question, and for not having looked around the forum much. Either way, thanks again!

Check the thread on TGP that Arislaf linked to for some good ideas.

 

And yes, as Craiganderton mentioned, if you drop a stereo width block after a dual cab, you can take the signal all the way down to mono if you want. And if you are going to go all the way to mono, may as well just drop a mono gain block after it since the Helix will sum the stereo signal to mono just before a mono block. So that works well, but does consume a block. On Helix is not a big deal, but on the Stomp blocks are in short supply.

 

Personally, regarding tips, I'd say experiment and see what you like. You'll figure it out over time. But definitely try different mics and distances. The general rule of thumb(s) to get you started, and some of these are my own personal preference are:

 

Probably my favorite cab that I use the most is the Greenback 25. I often use a dual cab block with it and pair to complementary mics. Like a '57 and a '121. Or a '57 and a '160. I'll either use a dual cab block or put two separate cabs in a split, then merge after.

 

A 2x12 or a 1x12 will be a little tighter than a 4x12.

 

I generally put dynamic mics closer (1-2 inches) and ribbon mics a little farther for some space (3-5 inches).

 

Complement a dark mic (ribbon) with a bright mic (dynamic).

 

And maybe don't start with two cabinets, but instead start with one that has your go-to speaker in it, then try different mics and see if you're getting the results you want from a single cab and mic. Cabinets are pretty DSP hungry, so if you are tight on DSP, maybe you can get by with one cabinet.

 

All my favorite OH IRs were mixed mic IRs, though, so I generally mix them. Again - personal preference.

 

On the favorite cabs - you'll eventually work out which ones you like the best. Try mixing not only mics, but also speakers. For example, the Greenback 25 with a cabinet that has V30s in it. Then mix mics on those. You can get some very nice results. And there are so many combinations your ears will tire out long before you get through them.