DI: Pre or Post

[whacker]

Usually not found in amps, but available in some external DI boxes, is the ability to tap a signal off the speaker line. Especially useful, though, is one of these that has compensating circuitry, that rolls off some of the high end to more closely approximate the response of speakers (speaker cabinet simulation). Otherwise you'd end up with really clanky highs (amps have a lot of HF hiss for various reasons). But for the dudes who play SVTs and the like, other than micing, this would be handy. You'd hear any amp characteristics being generated (but obviously without cab influence). Other than just liking a particular model of microphone and how it sounds with your rig, this is pretty practical.

Myself, I'm a pre-EQer.

 

[peterpalmieri]

Usually not found in amps, but available in some external DI boxes, is the ability to tap a signal off the speaker line. Especially useful, though, is one of these that has compensating circuitry, that rolls off some of the high end to more closely approximate the response of speakers (speaker cabinet simulation). Otherwise you'd end up with really clanky highs (amps have a lot of HF hiss for various reasons). But for the dudes who play SVTs and the like, other than micing, this would be handy. You'd hear any amp characteristics being generated (but obviously without cab influence). Other than just liking a particular model of microphone and how it sounds with your rig, this is pretty practical.

Myself, I'm a pre-EQer.

Palmer speaker simulators are very good, they can handle a load from the power amp out. There are other pre-amps that can do this as well like the Millennia TD1. But on many of these the total wattage it can handle is limited..

 

[whacker]

DIs like the ever-popular Countryman can be set to accept a speaker level signal, but I don't know if it shapes the signal in any way, or if it just passes it on as is.

A long time ago, Peavey had a box called the "EDI" (I think) that was a passive direct box for speaker connection.

Also, didn't Hughes & Kettner make something called the "Red Box" that was along these lines? Passive for connection to the speaker line, with some signal shaping... Probably lots of others as well.

 

[JimmyM]

I have a Red Box Classic that my wife got me for Christmas. The only signal shaping it has is a bass boost disguised as a 4x12' simulator and a bass cut disguised as a 2x12" simulator. But as far as DI's go, it's great and has a lot more edgy sound than your typical DI because it takes the output of the output transformer. But when I use it or any other DI with my B-15N, the soundman always turns it off in favor of a mic.

 

[the low one]

Some interesting commenst here. Pre EQ does seem to be the order of the day but that does seem to make all the expensive tube amps and Sansamp / MXR M80 etc etc obsolete, or does it ?? So many pro's seem to use the Sansamp and MXR M80 that you have to take notice.
I agree that what sounds good on stage will invairably not sound so good in FOH so I guess we have to trust the sound engineer at the end of the day.
Someone made the valid point earlier that it's all well and good listening to the FOH sound during sound check but that WILL change with a room full of psople.

 

[georgestrings]

Someone made the valid point earlier that it's all well and good listening to the FOH sound during sound check but that WILL change with a room full of psople.

Yup...



- georgestrings

 

[JimmyM]

That's why I often head into the crowd during our sets so I can hear what's going on. That and the old folks seem to dig it

 

[nemo]

with my B-15N

That explains everything. That amp must be heard in FOH.
Why didn't you said it earlier?

 

[JimmyM]

Didn't think it mattered. Regardless of the amp, I'm prefering the mic these days.

 

[joelb79]

No they're not. Why would you want a completely different sound in the house than in your rig? If my bass sounds completely different in the house than in my rig, there's something wrong IMHO.

I think Mr. B-15 this is because you have a total different tone goal than the majority of bassists out there.

 

[ogrossman]

I send my soundman the Pre-EQ signal because I trust him to make it sound good out front. Sending him the Post-EQ signal isn't going to help much if I don't trust him in the first place.

 

[JimmyM]

I think Mr. B-15 this is because you have a total different tone goal than the majority of bassists out there.

Thank you, Joel! But I really don't. I maybe go for a slightly angrier sound than most, and I'm not keen on anything past 5 or 6K, but I think the tones I go for are right in line with what most people are looking for. I just don't care about things like bleed or total pristine audio.

 

[dulouz]

Why don't manufacturers offer the option of having 3 levels of DI?

Good point!!! I play through an Eden Nemesis NC410 and the DI is only Post EQ. That is the only thing I don't like about it. Why doesn't it have a pre/post switch? Their answer to the question is that "Most of the people using the amp run the EQ flat anyway." Seems a bit odd to me...

 

[agedhorse]

Usually not found in amps, but available in some external DI boxes, is the ability to tap a signal off the speaker line. Especially useful, though, is one of these that has compensating circuitry, that rolls off some of the high end to more closely approximate the response of speakers (speaker cabinet simulation). Otherwise you'd end up with really clanky highs (amps have a lot of HF hiss for various reasons)...
Myself, I'm a pre-EQer.

A word of caution with speaker level DI's and some amps out there now, the output may not be ground referenced and in some instances, in the pin 1 grounded position, you can unintentionally short the negative side of the amplifier to the console ground and either damage the ground wiring in the console (primary ground path traces on the input section of the console PCB) or damage the amp itself.

On any amp where the output is BTL (either a bridged analog amp or a class D amp with a bridged class D output switch stage) this can be a very real problem. If you plan on trying this method, be sure to operate the DI in the ground lifted position (pin 1).

This is a relatively new problem that is comon with many class D amps on the market now.

 

[Vic Winters]

If sound guys like a Pre-EQ signal, and most do in my experience, then doesn't that make pedals like the Sansamp, MXR M80 , Hartke Bass Attack etc etc obsolete for live use apart from the overdrive/distortion features they have?

I'm curious about this as well. What about active basses, equalizers, sonic maximizers?

 

[Lonnybass]

I'm curious about this as well. What about active basses, equalizers, sonic maximizers?

All this stuff is well and good, and can make a bass rig sound awesome. But I find that in the majority of situations I've been in that have PA support, you're going to be run into a board and full effects rack anyway (compressor, gate, reverb/ambiance, EQ, etc.).

A point that hasn't been made yet that I'd like to throw out here is that your typical bass rig simply isn't going to have the same sonic characteristics as a PA cabinet (full range or otherwise).

What sounds good through an aggressively mid-boosted bass enclosure - designed to let you hear yourself through the din of a LOUD stage mix, wedge monitors, blazing guitar amps, etc etc etc - simply WILL NOT sound the same way through a PA system, which by design has a completely different set of performance parameters and engineered voicing.

Also, I'd like to point out that there are quite literally thousands of posts right in here in the TB Amp Forum that correctly suggest that players dial OUT the bass from their amp signal in order to:

1) Minimize clipping
2) Reduce how much their amp is taxed, and
3) Let the mids come through more clearly.

EQ for your bass rig.

Lonnybass

 

[oyobass]

I ran post EQ last night and again today. I found a reasonable compromise between stage and house sound, weighted towards the house.

My stage sound suffered a bit, since I had to roll off both the high and low end on the amp, but I got crunchy tube goodness in the house. Mmm- crunchy tubes!

I walked up to the board after the first set. The soundman had my channel fairly flat, with a slight rise in the upper mids to help me cut through. Not the extreme corrections I had expected. Running post is now my first choice, if it soounds good, from now on.

Oyo

 

[the low one]

I ran post EQ last night and again today. I found a reasonable compromise between stage and house sound, weighted towards the house.

My stage sound suffered a bit, since I had to roll off both the high and low end on the amp, but I got crunchy tube goodness in the house. Mmm- crunchy tubes!

I walked up to the board after the first set. The soundman had my channel fairly flat, with a slight rise in the upper mids to help me cut through. Not the extreme corrections I had expected. Running post is now my first choice, if it soounds good, from now on.

Oyo

Interesting.

I played recently and the sound man said afterwards he had to EQ out quite a lot of mids from my FOH sound. I use a maple neck P bass and quite like that mid growl but next time I may try the ‘color’ button on my MXR M80 which I usually leave off to see if that helps. I don’t like the sound of the mid scoop through my amp but I can EQ that out if it sounds good in FOH.

 

[JimmyM]

I'd let the soundman take care of it if he needs to and you should get the sound you like in your amp.

 

[georgestrings]

I'd let the soundman take care of it if he needs to and you should get the sound you like in your amp.

I agree - I don't enjoy myself nearly as much if I don't sound good... It shouldn't be all that difficult to sound good on stage, and through the FOH...



- georgestrings