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EQ Curve to Simulate Classic 8x10


Bankai
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Scenario:

I DI an amp head live to run it to the FoH PA. This takes the sound of the head, but the head’s gain and EQ have been set for the cab and thus the DI signal doesn’t sound quite right through FoH, as the sound that comes from the PA is not same as the sound that comes from the 8x10 the amp is connected to. This is due to the PA being FRFR (or close to), and the 8x10 being highly colourised.

 

Question:

What EQ should be applied to the DI signal when it arrives at the FoH desk to tailor it and make it sound similiar to how it does coming out of the 8x10?
 

So far, I’ve started with rolling off anything below about 30Hz and anything above 6.5KHz, but an 8x10 definitely isn’t linear between those frequencies. I was hoping maybe someone had previously done a plot/graph to show where one would need to cut/boost in order to ‘cab sim’ an 8x10. Specifically in this case, an Ampeg SVT810E.

 

I am aware there are other avenues which achieve varying degrees of success, such as using a specific cab sim DI, or using a clean DI of the bass before it arrives at the amp, or selecting ‘pre-EQ’ on the amp head DI (if fitted). However, they won’t achieve what I’m after so for this scenario please pretend those options don’t exist!

Edited by Bankai
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I’ve just typed a big long answer.

Then re-read the OP and realised I’d suggested things I had to pretend didn’t exist.

as @Steve Browning states - get a nice mic in front of the cab. Although it’ll only be on one cone, so you may as well have the equivalent 210...or even a 110.

And in the time it’s taken to edit that - you’ve said it’s not the option.

Edited by AndyTravis
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13 minutes ago, Bill Fitzmaurice said:

Response of a Fridge will be reasonably close to the chart for the Eminence B810.

https://www.eminence.com/speakers/speaker-detail/?model=Legend_B810

The only significant difference is that in a sealed cab there will be a response hump centered around 110Hz.

 

 

Beautiful, I’ll use that as a starting point.

For those curious, this is the graph on the link:

CC2B265E-1852-4F02-A57D-919B6CB3DA6E.png.9a88fb3caa1a72617694465c29930169.png

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1 hour ago, jrixn1 said:

What is it specifically about the scenario which means it must done using only desk EQ, and that you can't use a BDDI pedal?

First of all, money. It’d be £200 for a Sansamp BDDI.

Secondly, in this scenario I am not the player, I am the sound engineer. So I need a solution that is simple for the player(s). Not all bassists (or any musician) are created equal. With quick turnarounds, novice musicians, and many things to manage at once, I don’t wish to have an expensive little box on stage that can go walkies, or have its settings changed and mess things up. 

I dislike DIing a bass straight. It means you get none of the flavour of the amp head, the gain structure, the EQ, etc. All things which make a considerable contribution to our tone when we play. 

I dislike mic’ing a bass cab. They can get knocked, are an additional expense, and generally don’t capture ‘the full picture’. The mic adds as much colour as the cab does, unless you’re using a very neutral LDC or similiar, which is generally not viable in a small venue. 
 

I am aware it is quite commonplace generally to do take a dry DI and mix it with a cab mic, and have done this previously but find it introduces too many variables and still doesn’t really give a ‘gold standard’ end result.
 

The solution I am left with, is using a good quality DI from the head that is being used, so I get the ‘full flavour’. I’m lucky enough to be using a Midas M32R so I can do a lot to the signal once it arrives at the desk, and one of those is replicate the EQ curve inherent in an Ampeg SVT810E (the backline cab), and thus I now have ‘the perfect DI’. Perfect, as I have an exact(ish) replica of the sound on stage, and it requires no additional input from the musician on stage beyond setting up their amp as they would normally, there’s nothing to get knocked, or buttons to get played with by mistake, and it’s easy to manage when you have multiple acts on a night. Plus, the audial end result is (in theory) going to be superior to the other solutions.
 

Coming back to the point I made before; not all bassists are created equal. That goes both ways, in that this is my way of acquiring a good sound from those who are using backline or maybe their own lower end kit, or those who maybe aren’t as experienced and don’t really know how to deal with a Sansamp being put in front of them. And it’ll produce a far better sound than any of the other options. However, when a band is playing who has a bassist who knows what they’re doing with kit (chances are, one of you lot!) they’ll probably have their own Sansamp (or equivalent) and know how to use it. Or potentially, some well thought out rack unit accompanied by a FRFR cab for monitoring. And when that happens, it’s even better as I’ll take what they can give me from that and do even better with it.

 

The aim is to produce a consistent and good quality FoH bass sound, no matter the rig or the player. 
 

As I’ve got the 8x10 and not much to do at the moment, I think I might use SMAART and try and produce an exact impulse curve. I asked the question here as I was hoping someone might already have done it to save me the trouble!
 

I appreciate the sound of an 8x10 may not be the desirable tone for a lot of players, but the purpose of this EQ curve is for when someone IS using the provided 8x10, so that when they EQ the head to make the stage sound how they want, it has the same effect out front rather than producing an FoH sound that is different/sub-par.

Edited by Bankai
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39 minutes ago, Bill Fitzmaurice said:

Response of a Fridge will be reasonably close to the chart for the Eminence B810.

https://www.eminence.com/speakers/speaker-detail/?model=Legend_B810

The only significant difference is that in a sealed cab there will be a response hump centered around 110Hz.

 

 

Reading those response curves was how I was creating "cabinet sims" 20+ years ago, long before Speaker IR's became so widely used as they are now. I still have my 24 band digital graphic that probably has a whole bunch of curves programmed in to simulate as close to as I could given what I had to work with!

Sure, it was nothing new - but I suppose it was new to me as I started including distortion in to my bass sound.

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I get what you are trying to do (OP), but theres more to it than that.

Regardless of whether its head only, head and eq cab sim, or micd up from cab, you will still eq from there to suit the room etc.

The amp head may be pre or post, so if its pre you'll not be getting the same as stage sound anyway.

You would be better with some generic bass guitar typical eq settings and take from there.

In my experience the sealed 8x10 does sound amazing with a band - somehow makes everything for together well - but also makes the bass duller if that helps.

If your still determined for an 8x10 sim via eq - people in the helix groups will have done that, but it may be using more than one eq effect and even more than one type of effect, not just eq.

Edited by la bam
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15 minutes ago, la bam said:

Regardless of whether its head only, head and eq cab sim, or micd up from cab, you will still eq from there to suit the room etc.

Correct. Personally, I use SMAART to achieve that aim and then apply the result via a graphic at the end of the process.

 

15 minutes ago, la bam said:

The amp head may be pre or post, so if its pre you'll not be getting the same as stage sound anyway.

I'm a bassist as well as a sound engineer, so have no fear. The two backline heads I have here are an Ampeg SVT-II Pro (which has an in-built switchable DI and is used on post-EQ) and an Orange AD200B (which doesn't have it's own DI, so the 'slave output' connection is used with a high quality DI box).

 

15 minutes ago, la bam said:

You would be better with some generic bass guitar typical eq settings and take from there.

I don't see how picking some generic EQ could produce a better result than an exact EQ replication of a cab, thus a defacto cab-sim. Could you go into a bit more detail on this one and help me understand what you mean?

 

15 minutes ago, la bam said:

In my experience the sealed 8x10 does sound amazing with a band - somehow makes everything for together well - but also makes the bass duller if that helps.

In the case of the Ampeg unit, it rolls off at about 6kHz so compared to a lot of the more modern 12" based units that are increasingly commonplace it certainly is as you say. Still, using the impulse curve as a starting point, I can then tailor something to give the required presence. 

 

15 minutes ago, la bam said:

If your still determined for an 8x10 sim via eq - people in the helix groups will have done that, but it may be using more than one eq effect and even more than one type of effect, not just eq.

I hadn't thought of that, but shall start taking a look over there as that's a very good suggestion. I might see if I can find a nice 2x12" replication too, so there's something a bit more FRFR in my arsenal too for if someone has a similiar cab they bring to a gig. Thanks

Edited by Bankai
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You have to be careful using raw driver curves. They are measured with the driver mounted in a wall, so they're only accurate above where an enclosure affects the result, roughly 150Hz. A sealed cab doesn't add much, if anything, in the lows, but a ported cab will make the lows very different.

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2 minutes ago, Bill Fitzmaurice said:

You have to be careful using raw driver curves. They are measured with the driver mounted in a wall, so they're only accurate above where an enclosure affects the result, roughly 150Hz. A sealed cab doesn't add much, if anything, in the lows, but a ported cab will make the lows very different.

I’m going to snoop around the helix and kemper groups and see what I can find as it may be someone has already done the leg work but failing that I’m going to SMAART it with a measurement microphone so I get the whole truth and nothing but the truth ;)

But thanks for the link, as it’ll be a helpful start point

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1 hour ago, Bankai said:

I’m going to snoop around the helix and kemper groups and see what I can find as it may be someone has already done the leg work but failing that I’m going to SMAART it with a measurement microphone so I get the whole truth and nothing but the truth ;)

But thanks for the link, as it’ll be a helpful start point

I use these with my Helix when I'm messing around with IRs, though interestingly I don't use cab sims / miked-up cabs live at all.

 

https://redwirez.com/products/bigbox-bass

 

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On 04/05/2020 at 20:07, TPJ said:

Here is a page from a Helix whiz. He's created some 810 sims with parametric eq blocks on the Helix. You may be able to use the settings and see what you come up with if you have similar eq devices.

http://drtonelab.com/lab/8x10/

I’ve been using this in place of a cab sim for a while now. It’s very good (not sure how close it is though) and seems to have more of a kick over the cab sim. 

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1 hour ago, Bankai said:

Perfect ;)

The 1x15 on there is also very good. 

I do think a BDDI or the much cheaper Behringer BDI-21 would be a better option, as you will have more control over them. This scenario is exactly why they were developed. 

Edited by dave_bass5
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  • 4 weeks later...

My two penn'orth:

The most important, but trickiest, element you need to duplicate is the very sharp response dropoff at the top of the speaker's range. You can see this on the response graph posted above: you need to be aiming for a cutoff of at least 18dB per octave above about 5kHz. Very few desk or outboard EQs can achieve this without cascading more than one channel.

The next most important element is a rolloff of the low bass. This needn't be as steep as the top-end roll-off I mentioned previously though, so is easier to achieve with normal EQs.

With these elements in place you can fiddle about a bit in the middle: maybe a bit of a boost around 2kHz and a bit of cut around 500Hz? Again, see the response graph above, but I would argue that these aspects are a bit more 'tweak-to-taste'.

One cheap way to address your issue would be the Behringer Ultra-G DI box. This has a built in (switchable) analogue cab-sim. It's supposed to model a 4x12 rather than an 8x10, but I've found it to have a good and useful sound, and to be a reliable item, despite a few inevitable anti-Behringer sneers.

A more accurate and flexible way to get what you asked for would be to use a cab-sim which can make use of impulse reponses, and find an IR that exactly matches your preferences. There are many of these now, but probably most of them exceed the cost you want to pay, and have a lot of additional features that would be redundant or unhelpful for your purposes. I've been impressed by the Mooer Radar, which is relatively cheap. It has built-in IRs, including an 8x10, but you can also load your own IRs into it if you found one you preferred. And although its output is only on a 1/4" jack socket, it is in fact balanced (TRS), so a simple jack-to-xlr cable would presumably provide a suitable feed to your FOH desk. It does require a horrible wall-wart power supply though!

Good luck with your quest!

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