Neutral Cabs

[la bam]

Hi all,

Just wondering what people are calling "neutral" cabs?

I now have a helix and the frfr route cab wise is fine, but they only really do 1x12 or 1x15s.

So, if I'm back to bass amps, what are neutral options for 2x10s or 4x10s etc.

[Stylon Pilson]

If you want neutrality, why do you care about the cone size?

S.P.

[itu]

SP put a tough one!

Neutral cabs are a rare breed among bass/PA systems. The reason for this is the efficiency. If you lower efficiency you get wider/even response and vice versa. Hifi stuff has efficiency in the area of 0.01 - 0.1 % (this equals that 100 W of power creates 0.01 to 0.1 watts of sound). PA and bass systems may have efficiency up to 1 - 2 %. This is quite some more loudness than with Hifi systems. The price paid is the funny looking response.

Do you still believe that a wide & flat response is possible within reasonably small PA/bass systems?

[Bill Fitzmaurice]

2 hours ago, la bam said:

Hi all,

Just wondering what people are calling "neutral" cabs?

I now have a helix and the frfr route cab wise is fine, but they only really do 1x12 or 1x15s.

So, if I'm back to bass amps, what are neutral options for 2x10s or 4x10s etc.

Neutral means no coloration, ie., flat response. You can have flat response with any driver size. Finding a manufacturer who publishes measured response charts that prove their cabs have flat response is probably a fruitless quest, though.

[la bam]

Thanks, in theory a PA speaker would do (i am using a helix with speaker cabinet emulation), but a 1x12 just wont be enough, so just wondered if there were any say 2x10 or 4x10 cabs around?

I really dont want to be buying a pair of DXRs or PA cabs if i can help it.

[Bill Fitzmaurice]

A PA speaker might do, but the number of those which have SPL charts is dwindling as well. Much of the reason for that is the proliferation of powered PA speakers with on-board DSP. They don't need flat native response from the drivers, the DSP sees to that.

[jrixn1]

11 minutes ago, la bam said:

Thanks, in theory a PA speaker would do (i am using a helix with speaker cabinet emulation), but a 1x12 just wont be enough, so just wondered if there were any say 2x10 or 4x10 cabs around?

Are you looking for a powered speaker, or passive?  If latter, Fearless go up to a 2x15.

[stevie]

The only bass guitar cab I know that has half a chance of being neutral is the Greenboy F-series. Apart from that, your best bet at the moment is a PA cab. It's impossible for your usual 2 x 10 and 4 x 10 bass cabs to be neutral.

[BigRedX]

19 minutes ago, la bam said:

Thanks, in theory a PA speaker would do (i am using a helix with speaker cabinet emulation), but a 1x12 just wont be enough, so just wondered if there were any say 2x10 or 4x10 cabs around?

I really dont want to be buying a pair of DXRs or PA cabs if i can help it.

Just how loud do you need to be?

I'm using a Helix with a single RCF 745 (1x15 plus tweeter).

Most of the time when I have PA support I'm running the Helix with the master volume at 10 o'clock and the RCF at 3 o'clock which is plenty loud enough for a decent on-stage mix when we have vocals only in the foldback. I've done one gig with no PA support for the bass and that required me to turn the Helix up the just over half way.

[Hellzero]

I have this :

 

 

[la bam]

29 minutes ago, stevie said:

It's impossible for your usual 2 x 10 and 4 x 10 bass cabs to be neutral.

Is that because there's more than 1 speaker? 

[stevie]

Basically, yes. There's very little actual design input in these cabs. The basic principle is - keep sticking drivers in a box until it's loud enough. With multiple drivers you get lots of midrange cancellation, which results in peaks and dips in the frequency response. The off-axis response is hopeless and there is usually no HF.  When a tweeter is fitted, it usually operates too high to make any real difference.

[la bam]

 Thanks.

[Dan Dare]

You may well not like "neutral" gear (if such a thing even exists). To get an idea of what it might sound like, run your bass through your hi-fi (via a suitable interface/preamp). Flat/sterile? Check. Dull/lifeless? Check. No "heft"? Check. No amplification is "neutral". The trick is to find the one with the colouration/distortion that appeals to you. 

[jrixn1]

10 minutes ago, Dan Dare said:

You may well not like "neutral" gear (if such a thing even exists). To get an idea of what it might sound like, run your bass through your hi-fi (via a suitable interface/preamp). Flat/sterile? Check. Dull/lifeless? Check. No "heft"? Check. No amplification is "neutral". The trick is to find the one with the colouration/distortion that appeals to you. 

Well, he said he's got a Helix so it makes sense that everything after that is as neutral (flat) as possible.

[funky8884]

16 hours ago, stevie said:

Basically, yes. There's very little actual design input in these cabs. The basic principle is - keep sticking drivers in a box until it's loud enough. With multiple drivers you get lots of midrange cancellation, which results in peaks and dips in the frequency response. The off-axis response is hopeless and there is usually no HF.  When a tweeter is fitted, it usually operates too high to make any real difference.

Does this same cancellation effect 12'' and 15" multiple speaker Cabs ?

[stevie]

Yes. When they are positioned close to one another,  multiple speakers couple at low frequencies (they act as a single driver) and sensitivity increases. This is fine at very low frequencies where wavelengths are long, but at higher frequencies the sound produced by the individual drivers will start to cancel (be out of phase) as a result of the inter-driver spacing. It's the same principle that causes a single driver to roll off off-axis.

To avoid this when multiple bass drivers are used, they should be crossed over to a midrange driver before the phase cancellation takes place.

 

[stevie]

15 hours ago, Dan Dare said:

You may well not like "neutral" gear (if such a thing even exists). To get an idea of what it might sound like, run your bass through your hi-fi (via a suitable interface/preamp). Flat/sterile? Check. Dull/lifeless? Check. No "heft"? Check. No amplification is "neutral". The trick is to find the one with the colouration/distortion that appeals to you. 

You might as well run your bass through the earbuds on your phone.

[BassBod]

Going back a while, I tried the “flat” speaker approach.  Most impressive was the Euphonic Audio CXL 112.  It was a great cab,  but two things proved annoying - firstly it was something like 45lbs so took a bit of effort on those tricky load ins.  Secondly, it was a transmission line design, using a custom speaker, so if it got damaged it was hard to get a replacement - even EA couldn’t supply one a year or two after they stopped making those cabs.  

Now I’m using one or two TKS S112s.  They are voiced, but much less so than the SWR/Eden etc cabs from the 80’s.  I also still use a Bag End S15, again it’s voiced, but not that much.  

[stevie]

During the past few years of messing about with bass cabs, I've come to the conclusion that a flat response, low colouration, constant directivity cab is the best solution for bass - certainly for me - and not just for use with modellers.

[itu]

So is it a Greenboy, then?

[BigRedX]

24 minutes ago, stevie said:

During the past few years of messing about with bass cabs, I've come to the conclusion that a flat response, low colouration, constant directivity cab is the best solution for bass - certainly for me - and not just for use with modellers.

It certainly makes sense, particular live since hardly any PA engineers will mic up bass cabs. Therefore all your tonal adjustments are contributing directly to sound of the bass on stage and FoH and not compensating for the voicing of your cab(s).

[stevie]

30 minutes ago, itu said:

So is it a Greenboy, then?

No, I'm afraid not.

 

[stevie]

29 minutes ago, BigRedX said:

It certainly makes sense, particular live since hardly any PA engineers will mic up bass cabs. Therefore all your tonal adjustments are contributing directly to sound of the bass on stage and FoH and not compensating for the voicing of your cab(s).

Exactly. I think the bass guitar has suffered for many years from being confused with the electric guitar, where the speaker plays an important role in creating the sound. A bass guitar isn't like that. It's more like an electric piano or a double bass.

[Bill Fitzmaurice]

50 minutes ago, BigRedX said:

hardly any PA engineers will mic up bass cabs.

The good ones do. They'll take a DI for the lows, a mic for the mids and highs. The reason for the DI lows is to minimize stage rumble that a mic will pick up, and to get a better low frequency signal than the speakers can deliver. The limitation is that to do this the board needs enough channels to devote two to the bass.