How much bottom end can a Blues Jnr. take?

[SwamiRob]

Currently running a biamp setup for a couple of things I'm doing at the moment, and going into an Ashdown/Matamp 6x10 bass rig and a Blues Jnr copy. I'm just a bit worried about the potential low end going into the guitar amp.

I've got a few pedals involved before - running into an FEA labs multiband (crossed over at about 100hz), which is running the "highs" into the main input of a Vfe R.U.P multiband distortion, and the low end into the low effects loop return.

The guitar amp is running from the midrange band effects loop out of the pedal; which I've got the bandwidth controls cutting the low and high end as much as possible, to get rid of both bottom end, and some of the harshness of my top of my pretty high-mid heavy Fender Bullet (top end is lovely through a bass amp, not so much through an overdriven guitar amp however...). I then cut the bass & treble all or at least most of the way, and then boost the mids fully as they centre around quite a nice frequency that fills the sound out after all that shelving.

Everything else is routed to the main mix of the R.U.P. into the Ashdown.

My worry is however, that even with all that EQ, it seems to still have a bit of a noticeable lower end when turned up. I imagine the tone stack on the Blues Jnr. copy is quite weak in comparison to the other EQ, with "flat" actually being a bit of a mid scoop (Standard Fender stack cuts at 800hz and boosts at 400hz I seem to remember, but not too sure). I'm also not sure the R.U.P. cuts at a particularly aggressive dB/octave. Possibly the mid boost is actually dragging up some high bass with it, which would be more prominent on a bass? Without it however, the signal has quite a bit more lower bass frequencies going on which are gonna be even worse.

tldr: At lower volumes the whole setup sounds amazing, but when it all gets cranked to more gig like volumes I get a bit worried. The poweramp breaks up a bit, but nothing that seems to be absolutely flattening it, the sound just seems a bit low. The cab rattles a bit too, but the speaker doesn't seem to be farting out. I've heard plenty of people playing loud gigs with 15w oranges to convince me that 20watts is gonna be enough for pure midrange, just not completely sure that's what's going through it. Used a TS overdrive clone when I used it for band practice loud the other day, and cut even more bass with the filter controls it has. It sounded less rattley and had no problems, but sounded far too thin, didn't have the time to mess around seeing just how little extra cut from that I could get away with.

I've A/Bed it with a guitar too, but since the bass obviously sounds lower and I'm already paranoid about blowing it up, I can't really make any proper judgement from that. I'm also playing in BEAD which makes everything seem a whole lot worse then it might be.

Bit of a long post but thought I'd get as much detail as I could, because it sounds absolutely monstrous, and so much better then having the overdriven mids going into the bass amp with everything else. Really filled everything out in the 3 piece I was practising with the other day.

Ta for the help!

 

[Stumbo]

Maybe an HPF might work better on the BJC to control the lows.

 

[SwamiRob]

Yeah I'm considering an EQ pedal with a more aggressive top and bottom cut per octave, I just wasn't sure with 3 different layers low end cut whether I was being overly cautious. Judging by the diagrams on this, the shelving on the RUP is quite mild VFE Pedals | Boutique & Custom Effects | RUP distortion pedal .

The compressor at the start also should be cutting anything below 100hzish before those other 2 bottom end cuts, but not sure how aggressive that crossover is. I could make it a higher frequency but then the bass amp signal starts to sound a bit weak. And my other band I'm using this setup for, I need a bit of higher bass frequencies to boost on the pedal, for when I'm not using the effects loop.

Just seems like I'm using enough EQ and I shouldn't be worried, but just want to be sure before I start playing full gig volumes and setting the thing on fire! Also the Bullet has very little low lows in the first place, and it's taking quite alot of boosting with the compressor and some other pedal magic to get some out of it, although after all that pissing about I have got plenty to work with. So even before that initial crossover it's not got much sub, or even mid-bass going on.

Think what I'm after essentially, is the word of someone that's got some experience of subjecting guitar amps to bass signals, because I think I'm doing the right things to protect the thing from melting but just need to be sure!

 

[Downunderwonder]

EQ doesn't work like a proper HPF.

 

[Stumbo]

Think what I'm after essentially, is the word of someone that's got some experience of subjecting guitar amps to bass signals, because I think I'm doing the right things to protect the thing from melting but just need to be sure!

I use my adjustable HPF on my 1x15 guitar combo for medium volume stuff. I don't really push it. You can still blow it up with too much signal. Maybe @agedhorse will chime in. He has way more experience on most topics.

 

[JTE]

If your Blues Jr. copy has a tone stack copied from a regular Blues Jr., the three tone controls are not boosting/cutting three specific bands. They interact a lot, so while your setting is as close as it gets to "flat", it's not cutting the bass, simply not boosting it. To get what you're seeking I think getting the lows out of the signal before it gets to the drive and the amp, ergo the suggestions for a HPF.

 

[SwamiRob]

Cool I'll look into a full on HPF then, cheers for the help guys. I assume when you say it doesn't work like a proper HPF, does a H/LPF run everything below/above a certain frequency to ground? As opposed to a shelving EQ which just cuts/boosts at whatever curve it happens to by how ever many dB it's set to?

@Stumbo are you using that combo as your only amp or biamping? Either way do you mean by "too much signal" being weary of how hard you're hitting the front end of the amp generally? With all the cut going on I think I'm doing ok as it's killing the level a fair bit, have to crank up the gain a fair bit to get any overdrive if I haven't got any other dirt before it.

Looked it up after posting by the way, and the crossover on my multiband compressor is 12db per octave so that's doing some decent groundwork at least! It's not gonna get cranked for a while other then this weekend for a one off, where I'm using a one sound setup, so I'll just make sure I set the crossover on the comp fairly high, and cut out a bit more lows with the adjustable filter tubescreamer clone if needed.

 

[Munjibunga]

I'd use a crossover rather than an HPF for this application.

 

[SwamiRob]

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This is my crossover! Comes after the multiband comp, the bottom end of which goes into the low end FX loop, and away from the delicate little 20w thing!

 

[Jeff Bonny]

If you’re looking to roll off both lows and highs a Broughton HPF/LPF might be worth consideration.

 

[Element Zero]

How much? Enough until it pops.

 

[groooooove]

i'm normally the one to say "ehhhh don't worry so much"

but, i would 100% use a HPF into that blues JR. it's unlikely to end well without one.

with one, nothing to worry about and it'll sound great.

 

[BogeyBass]

I get it...
But then I don't really get it

I've had alot of fun with low watt bass combos. In the 100 watt range

But a single 12" and a pair of EL 84s just doesn't seem like it would do much. Up against a 6x10

Likewise guitar tone stacks and bass tone stacks are set different.

I'd see losing alot of tone and bandwidth when the 610 should cover the whole deal.

I've played bass through my 6L6 pair 40 watt blues reissue. But I was running a bass cabinet. Not a open back single 12"

I'll assume the output transformer has natural lowend roll off on the combo. The 60 watt Eminence 12" in my reissue is actually a very beefy good sounding speaker.

The low 15 watt Jenson or low watt speakers in the JRs just really won't do much. Or handle much lowend. I'll assume most the distortion wouldn't be much tube sound. It's more speaker distortion than anything. And many guitar speakers have voicecoils designed specifically to distort very early.

 

[Wasnex]

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This is my crossover! Comes after the multiband comp, the bottom end of which goes into the low end FX loop, and away from the delicate little 20w thing!

Not ideal as a crossover, but I guess it will sort of work and you can definitely have some fun and learn a bit. I checked out the manufacturer's webpage: If you are using the low and mid band, the high frequencies are cut off at 5kHz. You could get around this by using the low and high band. You would need to run the low band cross over at least up to 225Hz to avoid having a hole between the lows and highs, because 225Hz is as low as you can set the high band. Given the amp you are using for mids/highs, 225Hz is actually probably a decent place to start. Bass has a lot of energy below 200Hz so 20W is not going to go very far.

As far as worrying about the amp, I would not. The speaker on the other hand, that's what I would worry about. I used to biamp an SVT and a blackface Fender Twin. I used an Orban 672A parametric equalizer for the crossover. The lowest crossover frequency I could use was 200Hz. I ran the lows into an 810 and the Twin was loaded with a pair of JBL E120s, which are very robust guitar speakers rated for 150W RMS. FYI the Twin makes about 85W clean and I never ran out of headroom

 

[Gizmot]

Without seeing precisely what you’re doing, the only thing I can offer is to watch out how much EQ you’re using. If you’re using a lot of low EQ, you can easily use up any spare power and headroom your amp might have. Although it isn’t fashionable, cutting frequencies doesn’t eat much power or add noise.

 

[ThisBass]

I'd use a crossover rather than an HPF for this application.

You know a crossover does not prevent from transient noise?
Transient noise and what it means to woofer excursion
In first place I'd give preference to a HPF

 

[Bassosaurus]

Good crossover/HP suggestions here, but how loud will this be? A hard hitting drummer will probably drown out whats coming out of the 15 watt blues jr. And, if not, the other guitar will.

The speaker in the real ones is rated pretty high, and can take the mids you throw at it, but you may not hear much of it.

 

[Wasnex]

Good crossover/HP suggestions here, but how loud will this be? A hard hitting drummer will probably drown out whats coming out of the 15 watt blues jr. And, if not, the other guitar will.

The speaker in the real ones is rated pretty high, and can take the mids you throw at it, but you may not hear much of it.

If 20W is not enough at the selected crossover, then the OP always has the option to set the crossover to a higher frequency. The efficiency of the speaker is a significant factor.

 

[SwamiRob]

I get it...
But then I don't really get it

I've had alot of fun with low watt bass combos. In the 100 watt range

But a single 12" and a pair of EL 84s just doesn't seem like it would do much. Up against a 6x10

Likewise guitar tone stacks and bass tone stacks are set different.

I'd see losing alot of tone and bandwidth when the 610 should cover the whole deal.

I've played bass through my 6L6 pair 40 watt blues reissue. But I was running a bass cabinet. Not a open back single 12"

I'll assume the output transformer has natural lowend roll off on the combo. The 60 watt Eminence 12" in my reissue is actually a very beefy good sounding speaker.

The low 15 watt Jenson or low watt speakers in the JRs just really won't do much. Or handle much lowend. I'll assume most the distortion wouldn't be much tube sound. It's more speaker distortion than anything. And many guitar speakers have voicecoils designed specifically to distort very early.

Yeah I'm really not wanting to use it for much other then a small slice of midrange that I want to be quite a bit dirtier, while having cleaner highs and lows in a pretty scooped bass sound, pretty much want it to be in the same sort of range a slightly thinner sounding guitar signal. Doesn't need to be able to do anything other then be able to support the bass sound at higher volumes, anything subtle I'd be doing would be much quieter anyway. It's all mixed well at pretty loud but not quite gigging volumes however.

It's a copy by the way not a proper Blues Jnr (which I've heard the circuit is dead on other the components I imagine) but it's rated for 20w not 15w, know it's not a massive difference, but I've played some gigs with a VERY loud band with one of our guitars players using a 15w head. No problems being heard but he uses a sound which is very very light on low end, which is what I'm trying to get here too. Also I've subbed out the rubbish Celestion 75 for a slightly more respectable V30 from another combo, which seems to have cut a bit of bottom end (but obviously not from the load on the poweramp).

Just to explain the signal path again because it's a bit of a complicated one!

1st thing that the Bullet goes into, crossed over at about 100-150hz at 12db/octave. Split into low and high and the the low goes to the low FX loop of the next pedal (which only goes to the main mix output to the bass amp, doesn't ever make it into the 'guitar' signal).

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The guitar amp is plugged into the midrange FX loop out. The low mid band is cutting anything below 1.5k and the high mid band is cutting anything above 460k. Don't think it does this at a particularly aggressive dB/octave based on the diagrams on the website (and the dude that makes them has probably drawn them accurately knowing him). Could run the high mid band higher, but the Bullet is quite a toppy sounding bass, and sounds a bit harsh out of the guitar amp otherwise.

I've got the prototype of this pedal, so it doesn't have the 3 band EQ at the top, and the blend control is just a dry level. The dry is designed to fill in any gaps that you're not using with the 3 different bands. I leave the top end level at -inf, and the main output to the bass amp is dry signal from the high end of the compressor (minus some midrange going to the guitar amp) and the low end from the compressor coming back into the low FX return.

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Also been running this, the "fat" control boosts up mids and highs so the low end can end up being quite a bit quieter in comparison. Probably not the best thing to eradicate any little artifacts of low end but certainly makes the mid content much louder then it.


End of the day it seems like I need another HPF involved. Would be nice to have one that runs at something a bit more dramatic then 12db/octave, but maybe in tandem with the comp earlier in the signal chain, effectively doubling up the cut below 150hzish to 24db/octave, not counting the slight cut from the multiband distortion pedal.

Thanks again for the help guys, bit of a complex setup, but it sounds absolutely amazing so it's been worth all the pissing about so far!

 

[Bassosaurus]

Yeah I'm really not wanting to use it for much other then a small slice of midrange that I want to be quite a bit dirtier, while having cleaner highs and lows in a pretty scooped bass sound, pretty much want it to be in the same sort of range a slightly thinner sounding guitar signal. Doesn't need to be able to do anything other then be able to support the bass sound at higher volumes, anything subtle I'd be doing would be much quieter anyway. It's all mixed well at pretty loud but not quite gigging volumes however.

It's a copy by the way not a proper Blues Jnr (which I've heard the circuit is dead on other the components I imagine) but it's rated for 20w not 15w, know it's not a massive difference, but I've played some gigs with a VERY loud band with one of our guitars players using a 15w head. No problems being heard but he uses a sound which is very very light on low end, which is what I'm trying to get here too. Also I've subbed out the rubbish Celestion 75 for a slightly more respectable V30 from another combo, which seems to have cut a bit of bottom end (but obviously not from the load on the poweramp).

Just to explain the signal path again because it's a bit of a complicated one!

1st thing that the Bullet goes into, crossed over at about 100-150hz at 12db/octave. Split into low and high and the the low goes to the low FX loop of the next pedal (which only goes to the main mix output to the bass amp, doesn't ever make it into the 'guitar' signal).

[Invalid or Expired Link Removed]
The guitar amp is plugged into the midrange FX loop out. The low mid band is cutting anything below 1.5k and the high mid band is cutting anything above 460k. Don't think it does this at a particularly aggressive dB/octave based on the diagrams on the website (and the dude that makes them has probably drawn them accurately knowing him). Could run the high mid band higher, but the Bullet is quite a toppy sounding bass, and sounds a bit harsh out of the guitar amp otherwise.

I've got the prototype of this pedal, so it doesn't have the 3 band EQ at the top, and the blend control is just a dry level. The dry is designed to fill in any gaps that you're not using with the 3 different bands. I leave the top end level at -inf, and the main output to the bass amp is dry signal from the high end of the compressor (minus some midrange going to the guitar amp) and the low end from the compressor coming back into the low FX return.

[Invalid or Expired Link Removed]

Also been running this, the "fat" control boosts up mids and highs so the low end can end up being quite a bit quieter in comparison. Probably not the best thing to eradicate any little artifacts of low end but certainly makes the mid content much louder then it.


End of the day it seems like I need another HPF involved. Would be nice to have one that runs at something a bit more dramatic then 12db/octave, but maybe in tandem with the comp earlier in the signal chain, effectively doubling up the cut below 150hzish to 24db/octave, not counting the slight cut from the multiband distortion pedal.

Thanks again for the help guys, bit of a complex setup, but it sounds absolutely amazing so it's been worth all the pissing about so far!

V30 seems like a great spesker choice for this purpose. Do we get to hear this?