Why bother???

[JazzyLambert]

I have read in these amp forums that adding another cab to my rig and running at 300W @4 Ohms, instead of 175W @ 8 Ohms, makes virtually NO difference to the decibel output.

Why do people bother?

Also, if I have a sweet sounding amp that I can get sounding just as punchy and growling as I like, with nice slap sounds, then I run it through a DI pre-EQ, then why do I bother? ...The audience is hearing something else altogether. Wouldn't I be better off with a SansAmp or suchlike for gigs with DI?

Please excuse my ignorance on amps and such, but it seems that people might be spending large amounts of money on gear which is often used mostly as decoration.

 

[GeoffByrne]

Adding the extra cab isn't about necessarily boosting volume. The ratio of useable clean to distorted signal goes up too, and what you really get is the ability for more useable, clean and articulate tones without necessarily going louder. Of course, clean may not be what you want.

As for the second point, that's personal choice.

 

[T-Bird]

Hi.

#1. By adding the speaker area and halving the impedance and therefore in theory doubling the wattage does make a noticeable difference in SPL. If both of the cabs are of similar sensitivity or the additional one is more sensitive.

#2. Some play with PA support, others don't. Some like to buy gear, some don't. Different strokes for different folks.



In rock in particular LOOKS IS EVERYTHING. An ear shattering, tiny, super efficient boutique 2*10" with a 2000W class D power amp with SMPS, looks quite like that cute 18" stonehenge: the dwarfs might stomp on it . So the "Monster Rigs" it is.

On here ~1 240V/~3 400V world we have it easy, we have ALL the power we ever need ALL the time when within the reach of the power grid (99% of the time). People with less power available, they have to make it with anything that's available and usually that means that the PA is only for inaudible vocals and everyone else (bass/keys) have to rely on the back-line. And there more speaker area, greater sensitivity and more watts is a must. Guitars are no problem, a 50W tube amp can clear a crowded bar pretty quckly .

I most probably could play the majority of my gigs with my SWR WM10, but I'd rather schlep my full tube Fame BVH300, a 4*10" and 1*15" cabs. To have a sound that I like, and take the small PA with us instead of the huge (to us) out-door setup.

As for the DI: the audience next to the stage, the fans, will only hear Your rig, not the FOH.

Regards
Sam

 

[Pacman]

As for the DI: the audience next to the stage, the fans, will only hear Your rig, not the FOH.

Regards
Sam

Front fills. Don't leave home without them. I haven't toured with a rig in years.

 

[Kenny Allyn]

Unlike guitar many assumptions are made about the sound of bass going to the audience.

One is that you want nothing but clean, or a little sansamp induced dirt going to the audience, that assumes you don't need actual reaction from the amp. With a guitar the the amp is an actual player in the game it is all one system that you play even, if your only micing a little Fender deluxe amp. I know that these days with those digital multi-effect modeling devices many will say even ditch the guitar amp ... it's the Bose L1 mentality, but I doubt you will convince many guitar players to go amp-less unless they play in a straight cover or wedding band.

Keys players have gone for years now without having to really consider the amp, gone are the days of a REAL Hammond B-3 going through a big old Leslie cabinet or the sound a Fender Rhodes piano, it all comes from a digital model stored in a YAMAHA keyboard etc: Talk about looks I can still see an image in my head of the old says with 4 big wooden Leslies on stage turned backwards to expose the rotating speakers ... harkens from a time most on this board never knew, 99.9% of modern keys players would not go to the trouble now.

It was mentioned that in ROCK so much is about looks/image and I know that is true, what other reason would you want to have three Marshall stacks on stage, when a miced up 50 watt "plexie" would sound better, that's what Angus with AC/DC does I've read.

Bass players are somewhere between the keys and guitar thing these days ... less and less are willing to move a full "fridge" system around to play a club date, unless your 23 and still have a good back. Others will just DI and trust the sound guy (and that's cool if you have a gig like that). In my estimation many are taking the approach that the amp is needed in most all small to medium venues as it is running "barefoot" and is all the audience is actually hearing.

This is what I'm seeing, and you gotta remember I make cabs so I talk to a lot of pro players, downsizing is where they want to be. They don't want to be amp-less totally, but 45 pounds of cabinet and a 5 pound micro head is looking mighty nice at a 2am load-out. These smaller rigs act as essentially an onstage personal/band monitor for bigger venues where the FOH is controlled by the sound guy.

I use a series of pedals now to control how the amp sounds, the new Tech 21 VT Bass being just one example of the current generation of pedals to make your micro sound maxed out.

... Small. light and loud, but not gone is the trend I'm seeing.

 

[PSPookie]

Also, some heads will let you send a post EQ signal through the DI.

 

[KJung]

I have read in these amp forums that adding another cab to my rig and running at 300W @4 Ohms, instead of 175W @ 8 Ohms, makes virtually NO difference to the decibel output.

Why do people bother?

Also, if I have a sweet sounding amp that I can get sounding just as punchy and growling as I like, with nice slap sounds, then I run it through a DI pre-EQ, then why do I bother? ...The audience is hearing something else altogether. Wouldn't I be better off with a SansAmp or suchlike for gigs with DI?

Please excuse my ignorance on amps and such, but it seems that people might be spending large amounts of money on gear which is often used mostly as decoration.

For your first question... where in the world did you hear that adding a second cab (especially with a SS amp) would not increase your volume? It has a MASSIVE impact... volume, low end, headroom, everything.

Regarding DI, this is often discussed. If you are one that likes a clean, pure tone, then running pre EQ to the board is a wonderful thing. And, it doesn't result in the EQ you use with your little bass cabs to get your stage sound get in the way of the front of house sound system. The EQ and settings you use on stage would, in most cases, not be optimal or even useful in dialing in a good front of house tone with the much larger and wider sounding front of house system (in most cases).

If you are one who likes a more 'colored' tone from your amp, that is usually a combination of tubes, effects, AND speaker cab, which is why you see most guys using SVT's and the such having a mic in front of the cab. A 'post EQ' DI (if it is available) usually will not translate the tone you are hearing on stage, since much of the EQ, etc. is to get 'your tone' out of 'your cab'.

IMO!

 

[kraigo]

I have read in these amp forums that adding another cab to my rig and running at 300W @4 Ohms, instead of 175W @ 8 Ohms, makes virtually NO difference to the decibel output.

Why do people bother?

I disagree with your premise: 300 watts vs. 175 watts is only moderately louder but doubling your speaker cone area is a fairly big jump. Add the two together and you've got a very effective way to increase your volume. Not quite double it, but substantially louder.

KO

 

[KJung]

I disagree with your premise: 300 watts vs. 175 watts is only moderately louder but doubling your speaker cone area is a fairly big jump. Add the two together and you've got a very effective way to increase your volume. Not quite double it, but substantially louder.

KO

I believe, in general, doubling watts gives you the same +3db as adding another cab (+3db). You do both, you get +6db (remember, log scale.. this is massive), PLUS a little additional bump in the low end due to cabinet coupling. This is especially noticeable with smaller cabs and lower power amps (i.e., going from 150 watts into a single 112 to 300 watts into 2 x 112 is REALLY a difference you can hear and feel).

As I've also posted too many times, it's not all about volume, but also about an open, wide, non-compressed tone when playing aggressively (i.e., not running up against the limiting circuitry of the power amp, or the limits of a small, single cabinet).

 

[SuperDuck]

Also, some heads will let you send a post EQ signal throught the DI.

95% of the sound guys I've worked with will always push the little button for "Pre-EQ", though. It's usually the first thing they look for!

I've played direct-only on lots of gigs. It works fine. Small amp or no amp for me - let the PA do the work!

 

[greenboy]

I believe, in general, doubling watts gives you the same +3db as adding another cab (+3db). You do both, you get +6db (remember, log scale.. this is massive), PLUS a little additional bump in the low end due to cabinet coupling.

Usually you get around 5 dB - because the 3 dB mentioned above assumes you have doubled wattage, but in actuality power amps DON'T double wattage as the ohms-load is halved - 2 dB is more like it. Add the 3 dB of another cab being coupled and you have 5. The "PLUS a little additional bump in the low end due to cabinet coupling" is wrong - you already got 3 dB from doubling surface area and coupling. 10 dB is doubling volume by the way - 5 dB is a nice gain toward that.

Any additional perception of low end comes from having more drivers and thus more xmax/excursion. Instead of one cab that may run out of xmax early on, the added drivers now can make more low end before useful excursion has been surpassed.

This is especially noticeable with smaller cabs and lower power amps (i.e., going from 150 watts into a single 112 to 300 watts into 2 x 112 is REALLY a difference you can hear and feel). As I've also posted too many times, it's not all about volume, but also about an open, wide, non-compressed tone when playing aggressively (i.e., not running up against the limiting circuitry of the power amp, or the limits of a small, single cabinet).

Yes. You've gotten more excursion, more surface area and xmax, more wattage (but you won't be going to 300 watts but more like 225), and you won't be running into appreciable speaker power compression as early. You've also gotten more horizontal dispersion of midrange frequencies if drivers are situated one above the other.

 

[KJung]

Usually you get around 5 dB - because the 3 dB mentioned above assumes you have doubled wattage, but in actuality power amps DON'T double wattage as the ohms-load is halved - 2 dB is more like it. Add the 3 dB of another cab being coupled and you have 5. The "PLUS a little additional bump in the low end due to cabinet coupling" is wrong - you already got 3 dB from doubling surface area and coupling. 10 dB is doubling volume by the way - 5 dB is a nice gain toward that.

Any additional perception of low end comes from having more drivers and thus more xmax/excursion. Instead of one cab that may run out of xmax early on, the added drivers now can make more low end before useful excursion has been surpassed.



Yes. You've gotten more excursion, more surface area and xmax, more wattage (but you won't be going to 300 watts but more like 225), and you won't be running into appreciable speaker power compression as early. You've also gotten more horizontal dispersion of midrange frequencies if drivers are situated one above the other.

Cool. The point is, it's a LOT!!! And +1, different amp designs have different ratio's of wattage increase going from 4 to 8. Dave Funk put up a nice post about this a while back on why this is. I was using the wattage doubling as a simplification.

And yes, pushing a small cab hard versus pushing two cabs not so hard can really, really make a difference far beyond what the +db spec's imply, especially if you are going from 'not quite enough' to 'a little more than enough' volume in a given playing context. Thanks for posting the correct technical reason for this.

 

[billfitzmaurice]

I have read in these amp forums that adding another cab to my rig and running at 300W @4 Ohms, instead of 175W @ 8 Ohms, makes virtually NO difference to the decibel output.

Whomever told you that is incorrect. Adding a second identical cab will double both the system efficiency and current flow, for a net 6dB additional output. Where power alone is concerned going from 175W to 300W into the same cab will gain about 2.5dB, assuming the cab can make use of the power increase.

 

[JazzyLambert]

Keys players have gone for years now without having to really consider the amp, gone are the days of a REAL Hammond B-3 going through a big old Leslie cabinet or the sound a Fender Rhodes piano, it all comes from a digital model stored in a YAMAHA keyboard etc: Talk about looks I can still see an image in my head of the old says with 4 big wooden Leslies on stage turned backwards to expose the rotating speakers ... harkens from a time most on this board never knew, 99.9% of modern keys players would not go to the trouble now.



I recently played with a keys player who used a Hammond and genuine Leslie, which he sat on during the gig, and I can tell you ...there is no computer on Earth that can really emulate that sound.

I realize now that there are fairly full discussions on these subjects on these threads--------------


Does your rig really matter?

Soundmen - your DI or theirs? and other issues


BUT-- I really think that these issues should be radically and honestly looked into, because many, many players could be spending thousands of $$$ on gear that is either decorative or obsolete, or both. How often do players mike their cabs these days compared to DI,,, how about a survey on that?

 

[KJung]

BUT-- I really think that these issues should be radically and honestly looked into, because many, many players could be spending thousands of $$$ on gear that is either decorative or obsolete, or both. How often do players mike their cabs these days compared to DI,,, how about a survey on that?

While considering the question above, you also need to realize that even though many play with front of house support, many do not. And more importantly to your question, even many of those who have front of house support on most gigs rarely have a) their own monitor mix or b) a monitor system capable of generating a full, pleasant bass tone for stage monitoring.

So, I guess if you are in the small percentage of players who play with large, multi-channel monitor systems (or full in-ear systems), then I agree, a bass rig is less of an issue. If, on the other hand, you are like IMO the vast majority of gigging bassists playing casuals and smaller clubs, a bass rig is essential.

Regarding cab mic'ing, it's not much different than in the past. If you use a tube amp and a sealed cab (i.e., if a very 'colored' sounding rig is key to your tone, including speaker break-up, etc.), then the only way to go is mic'ing that cab. All those rockers still pounding those SVT's do it. For the rest of us, there never was much reason to mic a cab, and there still isn't!

And.... at least with regards to bass amplification (heads and cabs), IMO and IME (I'm 52)... things are MUCH better today regarding power, volume, full range sound, overall fidelity, weight, price, selection, etc., etc., etc.

 

[Intune]

When I think of B-3's & Leslie's, I think of stairs. 'Yeah, the easiest way for ya'll to load in is through that door up there." Dang, don't even show the hard way... And then after the show, "sorry 'bout all those stairs, that freight elevator is just so dang slow."

There are still a few keys here in Nash that use the B3 & Les. Everyone helps to cart them in because nothing can touch that sound.

Also, if I have a sweet sounding amp that I can get sounding just as punchy and growling as I like, with nice slap sounds, then I run it through a DI pre-EQ, then why do I bother? ...The audience is hearing something else altogether. Wouldn't I be better off with a SansAmp or suchlike for gigs with DI?
...but it seems that people might be spending large amounts of money on gear which is often used mostly as decoration...

Pre & post eq is the soundman's call. I usually go pre & a mic, best of both worlds but I have to watch my stomping. Mics, boots & wooden stages, oops...


It's the "tweener" shows where the PA can only handle vox & kick that a rig shines. The audience is absolutely hearing my rig. What are YOU hearing onstage? I have changed rigs during soundcheck, for various reasons, including monitors. All my stuff is big & heavy. I like to "feel" bass onstage. Within reason. But I need more decorations too.

A small amp & a 210 cab would come in handy sometimes. For small gigs. It would work for the big ones too but usually not the "tweeners" I mentioned earlier. I also don't ride the subway or have to use a compact car to move gear.

On large, pro sound re-enforced gigs, I probably don't need my rig. Row after row of power amps & huge side-fills is a good sign. But why not plop the Mesa 400+ and the Berg 610 & Acoustic 301 up there? I'm not carrying it.

 

[Bluesy Soul]

I have read in these amp forums that adding another cab to my rig and running at 300W @4 Ohms, instead of 175W @ 8 Ohms, makes virtually NO difference to the decibel output.

Thank you to KJung, greenboy and BillFitzmaurice for correcting that misinformation.

In addition to the mistaken premise, others have pointed out that not every band has a PA adequate to act as a true FOH and BOH system, nor does every club. In these cases, providing your own amplication system is necessary.

Another big issue, however, is control. I play at some clubs that have wonderful FOH/BOH systems, but no competent soundmen. (Soundpersons?) Unless and until these same clubs prohibit me from bringing my own system, I'm not giving up my last fighting chance. Neither are my bandmates, nor do they want me to.

It's a valid issue; but it's more complicated than the math/physics you incorrectly performed.

Bluesy Soul

 

[JimmyM]

To answer the original post: whatever.

 

[JimmyM]

Also, Angus does use a 50w Plexi mic'ed offstage, but he also uses 4 stacks onstage.

 

[()smoke()]

great replies by some knowledgeable folks so far!

i just wanted to add another wrinkle to the idea--the acoustics and PA rig in one of the venues we play often enough to consider it our 'home base' doesn't bode well for getting low frequencies to the audience, apparently in part because of the layout of the space and stage

just a couple of days ago, i asked our sound engineer about going without a stage amp, straight into the board and he suggested that in this particular venue, my stage amp is actually providing the majority of the low end of the bass that is heard in the audience

so, even with PA, sometimes the stage amp is necessary to fill in the missing sonics