Going to add a cabinet

[drbassman]

I've been mulling this over for months and I think I'm going to add a cabinet to my Mesa rig.  I've been waffling between a 15" vs. 4x10.  I already have a great 15" Mesa cab, but I want more bass than the 1x12" Scout main cab is giving me.  Our club is small, so volume isn't an issue.  I just want more bottom end and I want it to be relatively clean, not muddy.

What do you think?

[Dave W]

IMHO you'll get more bass with the 1x15.

[drbassman]

IMHO you'll get more bass with the 1x15.

I was thinking that, but I'm a real novice when it comes to cabinets!  My audiology background tells me you're correct, but numnerous bass buddies locally keep telling me 4x10s have "just as much bass."  I find that hard to believe knowing how the size of the speakers and wave lengths generated by them (and freq resp) will have an effect.  Maybe the differences are small and not that discernable to the naked ear, but I sure can hear the difference between my Mesa 15 vs. the 12.

[Dave W]

The 4x10 will probably be louder, depending on the cabinet design, and some people mistake a louder low end with more bass.

[drbassman]

The 4x10 will probably be louder, depending on the cabinet design, and some people mistake a louder low end with more bass.

Understandable.  I've been looking at some of the lower priced 15" cabs, not going to go the Mesa mega-bucks route.  With my 92 TB plugged into the Mesa amp, I rarely turn the main volume up beyond 3.5 when gigging!  The 300 watt head gives me plenty of room and drives the heck out of the speakers with ease.  I like the looks of the Ampeg flip tops and the speaker should handle the output easily.  It would make a nice portable rig too.

[Pilgrim]

IME the 4x10 will be a cleaner sound, but not necessarily with stronger low end.

I think Bill is a traditional-sound guy, so the 15 probably will fit him better. 

[drbassman]

IME the 4x10 will be a cleaner sound, but not necessarily with stronger low end.

I think Bill is a traditional-sound guy, so the 15 probably will fit him better. 

You know me well Al!  I'm about to push the button on an Ampeg flip top 15" cab with an Eminence speaker.  It should do the trick in my venue.

[4stringer77]

What, no phil jones?
http://www.philjonespuresound.com/products/?id=8
Think of all the bass two 5" speakers could provide... somehow

[Granny Gremlin]

IMHO you'll get more bass with the 1x15.

This completely depends on the drivers, and is actually not likely to be the case (do the math, the volume of air in 4 10" cones > the volume of air in a single 15).

The problem is that 4 10s will also (tend to) give you more top end (upper mids really).  This can be counteracted with driver choice (e.g. my DIY 8x10 with vinrtage Rola woofers has very little top compared to my Musicman RH115 with EV SP15c fullrange driver, which is not typical).

The main thing all around is if you want clean bass extension (vs the illusion of more bass, but not actually deeper bass) avoid bass reflex cabs altogether (go for accoustic suspension/sealed, horn or transmission line... I guess isobaric if size is a factor, but there aren't too many of those on the market that I'm aware of).  

IME the 4x10 will be a cleaner sound, but not necessarily with stronger low end.

This is also not true - completely depends on the driver (mostly how stiff the cones are).  E.G. a vintage Ampeg 8x10 is not clean at all (medium-light guitar cones on those custom drivers; break up more easily than stiffer bass guitar or PA woofer cones) ...assuming that you're running it at the same percent of power handling as whatever cab you are comparing it to.  If you only give it 100 watts it'll be pristine (amp/effect distortion doesn't count). Stiffer cones also have a lower resonant frequency ( which is generally indicative of the lower limit of the driver's useful response, but cab type is also a factor there).

So basically for more/deeper and clean bass you want:
- any cab type other than bass reflex (or open back, obviously)
- as much cone volume as you can stand (i.e. to move around)
- the stiffest/heaviest cones possible (within reason; remember Hartke? alu cones create other issues; some like, some don't)
- total cab power handling that is at least double if not triple what you'll be throwing at it

[Aussie Mark]

I'm about to push the button on an Ampeg flip top 15" cab with an Eminence speaker. 

Think twice - those cheaper PF cabs fart out at volume.  If a single 15" floats your boat, I'd look at one of the repro cabs made by Bruce at fliptops.net.  I've got one of his sealed 15" cabs with an Eminence Legend - I know that $524 is more than the Ampeg PF115, but with the Legend speaker it will handle anything you throw at it, and the sealed cab has a lot of old school punch.

http://www.fliptops.net/catalog/p-100775/speaker-cabinet-1x15-b15r-b15e-style

[Dave W]

This completely depends on the drivers, and is actually not likely to be the case (do the math, the volume of air in 4 10" cones > the volume of air in a single 15).

It does depend on the drivers, but I'm talking about frequency response.

The main thing all around is if you want clean bass extension (vs the illusion of more bass, but not actually deeper bass) avoid bass reflex cabs altogether (go for accoustic suspension/sealed, horn or transmission line... I guess isobaric if size is a factor, but there aren't too many of those on the market that I'm aware of).

It's true that a sealed cab will go lower without cutting off like a bass reflex cabinet. But there's a dropoff in volume as the frequency decreases. Plus there's the problem that a sealed cab designed for optimum bass response with a driver that can deliver the specs and handle the power is likely to be much larger than a bass reflex cabinet.

Bass reflex cabinets will stay popular with bassists.

[Granny Gremlin]

It does depend on the drivers, but I'm talking about frequency response.

I do not follow you here.  F response is very dependent on the driver (the primary factor actually, with the cab design being secondary to that).  

It's true that a sealed cab will go lower without cutting off like a bass reflex cabinet. But there's a dropoff in volume as the frequency decreases.

Yes, but this rolloff is a very slow and gradual taper  which is natural to the ear (vs the quick  fall off the cliff of ported).  It is a bit of a matter of taste, and I tried to express that (though granted in my anti-ported cab biased way - it's been a while I guess but I've always been honest about that slant).  The industry's obsession with flat F response graphs has led to a massive groupthink I have found.  Remmeber 3 db is the smallest change in volume that the human ear can detect, and if the rolloff of a sealed cab is only 6 db per octave, that means you can actually hear deeper bass than the same driver in a ported cab; it is useful response despite not being flat.  Flat is a gimmik (and in fact many manufacturers, this goes double for hifi,  design cabs to meet that spec vs just sounding good and the graph be damned). This, to me, is preferable because you don't get such a huge difference between fundamental response of open E vs A ( most instrument drivers' resonance is well above 40Hz; ported cabs have no response worth talking about below that point, but sealed cabs do.  From there you can get a better balance with some judicious tone control/EQ use.

Anyway, this illustrates what I mean (I didn't make this graph, and would be the first to admit that the scale used is somewhat biased in favour of sealed, but it still shows that there isn't necessarily that much to be gained from ported cabs aside from size reduction).  Not shown is how (depending on port tuning) there can be a response bump before it takes the characteristic nose dive.  Though technically this isn't a problem unless it's a reference application, depending on where that bump is it can create an annoying loud note (or 2) as you move along the fretboard.



That said, the only time I think a ported cab is an acceptable option (again, IMHO) is with larger drivers (or at least ones with very low resonance).  For example, bookshelf hifi's with 5" woofers in ported cabs are stupid, but 15" Tannoy Gold studio monitors (ported cab) are amazing (though much of that is also due to some other factors which are irrelevant here, the point is I don't see bass reflex as a handicap in that situation, though it's still not my preference).

Plus there's the problem that a sealed cab designed for optimum bass response with a driver that can deliver the specs and handle the power is likely to be much larger than a bass reflex cabinet.

Bass reflex cabinets will stay popular with bassists.

Yes, I alluded to the size issue above and I know bass reflex ain't going nowhere (whether it'sd hifi or instrument applications we're talking about).  But if size was the only issue, we'd all be rocking single 1 x 10 or 12 isobaric cabs exclusively (isobaric cabs being even smaller than ported, given the same driver... the drawback is cost and efficiency), and that's just not the case (see; 8x10, 2x15 etc or the very clear example staring us in the face in this thread: extension or secondary cabs).

Anyway, my point wasn't to say you need to do this, just explaining what factors result in the stated desired result (and to correct a few categorical statements).  Not all points need to be heeded to get a satisfactory result for the OP, and the pros / cons were stated or obvious so that people can make their own decisions.  ... but if you want to go all the way, there's the checklist.

[Dave W]

 

Bill asked for opinions, not a book on audio theory, ferchrissakes.

Of course the driver has to be able to deliver the goods, that's a given. So does the enclosure.

Bottom line for me: I've played 1x15s and 4x10s of a number of brands, and every one of the 1x15s had more bass. Every one, no question about it. The sealed 4x10 Ampeg included. And while I haven't seen frequency response charts on all of them, the ones I've seen confirm this. That's good enough for me.

[clankenstein]

just out of curiosty,what cab are you playing through granny g?

[drbassman]

Wow, nice treatise on cab design and speaker interactions.  Bottom line for me, is I usually over-buy stuff and that works fine.  But this time around, I just wanted to go low brow for the little club we play in.  I'm getting the 15" flipper from Ampeg.  Found it on sale for $330.  If it farts on me, I'll upgrade the speaker myself.  I'm not expecting volume problems, as I said before, I don't drive my speakers hard in a 3 piece band playing in a club with 100 partiers.  We have made a concerted effort to not overplay and overcrank the volume as our crowd is older, like us, and they like to talk and drink as well as dance.  If we get too loud, they bitch!

If I were doing stage work,  I'd be buying top of the line drivers/cabs.  It doesn't take much to convince me to buy top quality, I'm a sucker for good equipment.  For now, I do want more bass or bottom.  If it's not crisp, I don't care as long as it's not grossly distorted.

I have found, over time, that the 12" radiator cab from Mesa is easy to distort while the 15" cab can take anything I've thrown at it.  I'd lean toward one of those 15" cabs if they weren't $1000 street price.  I like the look of those flip top cabs by Bruce, thanks for pointing those out Mark.  I'll keep them in mind.

Thanks everyone, this has been educating.  When I was practicing audiology decades ago, our study and application of sound theory was confined to human hearing at the level of the external, middle and inner ear as well as central auditory processing by the cerebral cortex.  Didn't do a lot of work in the environmental acoustic realm except assessing hearing aid performance in the field by users.  The other stuff was reserved mostly for the industrial audiologists and acoustic engineers working in factory environments. Where would we bass players be without acoustic engineers?