Head/Cab Vs Combo

[Leonidas]

Hey guys, I've been looking into amps and realized a lot of people will use a head and cab, and others will use a combo. All the amps I've ever played through have been combo amps. What is the general advantages and disadvantages of each? Why would one go for a head/cab when they could get the same amp in combo form?

Just lookin for everyone's input... :)

[Spudman]

What is the general advantages and disadvantages of each? Why would one go for a head/cab when they could get the same amp in combo form?

:)

That's what I say.

I think the tubes in a combo have a shorter life span because of the vibration. But you only have to make one trip from the car to the stage with a combo amph versus two for the head/cab combo.

The good thing about the two piece version is that you can have a dynamite cabinet and run a variety of amphs through it. What ever the occasion calls for. Still you'll be making two trips. The good thing is on a large stage you can put the head by you for convenience and the cabinet somewhere else if you have plenty of speaker wire.

[Tone2TheBone]

I remember the old days (ok I hope I'm not too old) when cats used to call them "brains". "Yeah man I got me an Ampeg brain and it's groovy".

Cabinets if you have the room are suh-weet sounding but then so are combos with great speakers. Anymore I'd do a combo over a "brain" and cab. If it's a big combo then put wheels on it like I did!

[Katastrophe]

Combos are great for portability, and it is certainly possible to get great tone from a combo. I went with a combo because it's cheaper, and easier to lug around.

My old Marshall cab, with its closed back, I think got better forward projection of sound than my open backed combo does now, IMHO. When playing a distorted rhythm, it just sounded huge. It's hard to describe, but during heavy palm muted sections I would get this great "WHUMP" sound that you could feel as well as hear that was great. The downside was the cost, and it was heavy, and probably too much rig for small clubs.

A 30-40 watt head and closed back 2X12 cab, however, might be the best of both worlds...:D

[Tone2TheBone]

Whump is a perfect description of closed back Marshall cabs. :)

[Cranium]

Alot of combos also rattle a bit unless your playing at high volumes, combos are good for stage use, but head+cab(s) might probably be better for big places, I prefer heads with cabs over combos but its a personal preference, I only like Fender Combos cause thets pretty much all they make. :)

[Carlström]

stacks look cooler, what else is there to think about?!?!?! ;)


What i like with stacks is that when you buy them is that you choose your amp, and you choose your cabinette. Of course it's just to swap the speakers out in the combo if you ain't happy with it....but the amp you want might not be avalible in 2x12 or 4x10 or whatever speaker combination that REALLY does it for you.

cheers

[Leonidas]

Thanks for all the replies guys.

Ok, from what I've gathered... the advantage of going with head/cab is that it offers more versatility in that you can select what kind of cab you're running. Such that you can get a 4x10, 2x12, 1x15, etc... In addition to that head/cabs are available in higher wattages so they get much louder, which is better for playing large venues, etc...

Now my question is this (this is hypothetical):
Say I wanted a Valve Jr, which is a mere 5 watts. I understand the dynamics would be different if you were running, say a 4x10 cab with it, compared to a single speaker. Now, could the head version of the valve jr be significantly louder than the combo if you were to run it into a large cab?

[Cranium]

I would think so, if the cab has bigger speakers like 12" it should be louder, it also depends where your using it.

[Bloozcat]

Now my question is this (this is hypothetical):
Say I wanted a Valve Jr, which is a mere 5 watts. I understand the dynamics would be different if you were running, say a 4x10 cab with it, compared to a single speaker. Now, could the head version of the valve jr be significantly louder than the combo if you were to run it into a large cab?

The simple answer would be "yes".

Even if the speakers (single vs. pair/quad) have the same SPL (efficiency), the multiple speaker arrangement is moving more air and will therefore sound louder. The dynamics may favor the single speaker (or may not), but that may be a factor of speaker size and/or construction. There should even be a difference in the perception of the loudness if you were to go from the stock 8" speaker to a 12"...given an equal SPL for both.

Having said all of that, there is a law of diminishing returns. A 4X12 cab with 4- 150 watt speakers is designed to be pushed by a head running lot of wattage. Some cabs won't sound right unless there's some considerable power being delivered to them.

So far I've run my Valve Jr. head through a single 12" G12H30, a single Eminence GB12, a 2X12 cab with G12H30's, a 2X12 cab with Weber C12N's, a combo amp cab with 2X12 Mojotone MP12RHD Alnicos, and my Ampeg V-2 4X12 cab with the original Eminence speakers. Each set-up sounded a little different, but in each case the 2X12 cabs definitely sounded "bigger", with more projection. Just for the record, the VJ sounded best through the Webers at 16 ohm (to my ears anyway). The Ampeg 4X12 sounded the worst (too thin, not enough projection).

[6STRINGS 9LIVES]

Just a quick note regarding amp/ cabinet set ups ... the 1st company to offer seperate amplifier and cabinet set ups was fender , in December 1960 fender released their " piggyback" amps . the 1st was the fender showman which was essentially a twin in smaller box and a seperate box containing an elabourately ported JBL speaker , the system provided for more punch and projection resulting from the closed back sealed and ported cabinet , it also served to lighten the load by seperating the relatively heavy twin chassis and its massive transformers from the speakers , two boxes but each lighter than a combo twin .. one thing to remember before plugging your combo or head into a cabinet is to make shure that the impedence matches , cabinets can be wired in series or paralell to give a 4 , 8 or 16 ohm load , plugging a 16 or 8 ohm cab into a head or combo designed for 4 ohms is one way to fry your output transformer also never hook up a head or combo to a cabinet using a guitar cable it will also cook the output transformer in short order , use a proper 18 guage speaker cable and you'll be fine .. I often record using a 5 watt fender champ with its internal speaker unhooked into a 4 ohm sealed back 2-12 cab , it sounds amazing , a little louder and way more bottomy ... 6S9L

[Robert]

I love the head/cab setup (although I don't have a head!) because you don't get the rattle problems like cabs often suffer, and as people have mentioned already you can use your amp with different cabs and so on. I don't think a combo cabinet will likely sound as good as a quality speaker cabinet either. There's a reason for those "Marshall walls"! But even a good 2x12 cab can make a huge difference in tone - my Hellhound is a good example of this. It now sounds much better than it did as a combo. Now I just wish I had the head version instead of the combo...

Heavy? No, not my Avatar cab. It's really light and easy to move.

[Leonidas]

Hmmm, now i'm leaning more toward the head/cab thing...
Thanks for all the tips guys, you've shed a lot of light on the subject.


But even a good 2x12 cab can make a huge difference in tone - my Hellhound is a good example of this. It now sounds much better than it did as a combo.

I thought the Hellhound sounded great before, but even better.. Robert, have you tried the ad50vt into the avatar yet? I'd be curious to see what you think.

My next purchase will most likely be a valve jr, but I am undecided on whether I should go with the combo and be done with it, or try the head and maybe a decent 2x12 cab. A cab could give me more versatility with my vox, as well as be useful in future amp GAS attacks. :D

[Robert]

Yes, the AD50VT just blooms through a good cab! It's like night and day. The AD50VT combo cab isn't very good to be honest. I think that is a bigger problem than the stock speaker in the amp. Hook it up to good cab instead (or just get the AD100VT head) and you'll be all smiles. ;)

Get the cab + head and have no regrets! I know I should have a long time ago.

[TS808]

Yes, the AD50VT just blooms through a good cab! It's like night and day. The AD50VT combo cab isn't very good to be honest. I think that is a bigger problem than the stock speaker in the amp. Hook it up to good cab instead (or just get the AD100VT head) and you'll be all smiles. ;)

Get the cab + head and have no regrets! I know I should have a long time ago.

Robert,
What type of speakers are in your 2 x 12?

Do you find that different speakers significantly color the tone of a modeling amp? That's often the argument from the manufacturers, but I often wonder what a set of Eminence Texas Heats would sound like in my AD100VT.

The AD100VT has 16ohm speakers (Vox's own, not the 70/80s) so I was thinking about putting in some different speakers. The Neodogs of course are a good choice, but I don't want to spend $400 on two speakers.

[Robert]

I have Celestion Seventy-80 in my cab. Speakers sure make a difference, but I think the cab is even more important. I don't like the combo cabinet in the Vox AD50VT.

[oldguy]

Lots of good info here, everyone. You have all kind of confirmed what I found with a separate cab/head configuration. I find a 2x12 cab does indeed project better. My Avatar cab has one Celestion Vintage 30 and one G12H. I'm not really sure that the Avatar is as good as a sealed back ported cab, but it really brings the Valve Jr. head to life. I've also plugged my Traynor YCV-40 into the cab, huge difference. I'd like to experiment with other speaker combinations, alnicos, 10 inch vs. 12's,etc. One thing I'd like to add from past experience is power handling. With a little amp like the 5w Valve Jr., I think the best sound will come from the lowest rated speaker (as long as it's a quality speaker) that you can load in the cab. E.G.- A pair of 20w Celestions will sound much better than a pair of 200w E.V.s. The lower rated speakers will move the air better and give more of the aforementioned "WHUMP"! I think Eminence is building some really fine speakers, as well as Weber. I wonder what TWO Valve Jr's would do w/ two 2x12 cabs run through stereo effects w/ an A/B switching box setup?;)
One more thing: about combo amps... many manufacturers have overcome the vibration/rattling issues, but I've found that any combo will beat tubes to death, and while tube isolating rings (dampers) and well made and NOS tubes will give much better results, the best isolation characteristics come from seperate head/cab setups. IMHO there is a definite advantage to seperating the chassis from the speakers and NOT having one enclosure providing a path enabling vibration to affect the tubes. Plus I can carry the V. Jr. head in one hand and the Avatar cab in the other. One trip w/ a "balanced" load.
There are some good mods available for the V. Jr. also, and it might be easier w/ the head only version, plus the earlier hum issue has been fixed on the heads. Just my two cents worth, not trying to sway anybody's decision!:D
Glenn

[Bloozcat]

You know it's funny that some people will go through all kinds of painstaking efforts when building (or choosing) a combo cabinet (I'm not excluding myself here). It has to be the right wood, maybe multi-ply birch or solid pine. Then it has to be constructed just right with dove tail or finger joints. Then the baffle has to be just right...maybe a thin, floating baffle that's designed to flex, or a thick stiff baffle that's won't affect the tone and projection of the speaker. The speakers may have to be front mounted for maximum dispersion of sound, or rear mounted for better projection. They might even go as far as figuring out the volume of the cabinet and how that'll affect the tone.

And after they go through all of that...

...they stick an odd size metal chassis in the open back cabinet, with tubes and transformers hanging down into the resonance chamber. :confused:

If it's one's goal to achieve a particular tone by manipulation of the design and construction of a cabinet, then there's really only one way to maximize those efforts - build a stand alone cabinet. Now I know that many will argue that their combo amp sounds great - and many in fact, do - but if it's perfection that one is striving for (if that's possible at all), then the stand alone cabinet is the way to go. I like my combos just fine, but they always seem to sound better when I plug them into one of my 2X12 cabs.

To use a racing anology: Building a combo amp cabinet to maximize tone is like building a 750 HP nitro fueled V-8 and then sticking it into a stretch limo. Yeah, that motor will scream and it'll be the meanest stretch limo around, but do you think it has a chance against a funny car with the same motor? And after all, what are you trying to do? Light up the night sky with a screaming machine, or look good with your impecably constructed, but highly inefficient box?

(A bit of hyperbole I know, but it's often useful in getting a point across. For the record; I haven't even persuaded myself to get rid of all of my combos with that arguement ;) )

[Tone2TheBone]

Dang I was going to ask you how much you wanted for your combos Blooz.... :)

[Spudman]

So Blooz...

Which cabinet do you think work better for an open backed combo amp? An open backed 1x12, 2x12, closed backed 1x12 or 2x12? I'm limiting the choices because the reason we have combo's is so we don't have to pay a roadie to lug our 4x12's around.

Certainly some combination should be optimal in conjunction with an open backed combo? I don't think this has specifically been addressed yet. Which do you or anyone else think is the "holy grail" for additional sound?

[Leonidas]

So Blooz...

Which cabinet do you think work better for an open backed combo amp? An open backed 1x12, 2x12, closed backed 1x12 or 2x12? I'm limiting the choices because the reason we have combo's is so we don't have to pay a roadie to lug our 4x12's around.

Certainly some combination should be optimal in conjunction with an open backed combo? I don't think this has specifically been addressed yet. Which do you or anyone else think is the "holy grail" for additional sound?

Spud, this was my next question... But my question was more along the lines of "what would work better with a valve jr head". But again, it seems that there will be a vast array of opinions because it is another thing of personal preference. I also am looking at 1x12 or 2x12 with open or closed back... There just seems to be so many variables in selecting a cab, maybe too many. :confused:

[Robert]

My 2x12 Avatar is closed back. I really like it. My Hellhound sounds soooo much better through this cab!

My advice - test! I know it may be hard to A/B open back/closed back cabinets, but you can never know for sure what you'll like more until you test both.

[Bloozcat]

OK, this is my opinion based upon my experiences. Others may have different experiences:

My favorite speaker cabinet is the semi-open back type. By that I mean the type with an oval cut out on the back which allows for good bass response while also allowing the sound to sort of "bloom" from the cabinet and around the stage area. There is still plenty of forward projection with this type of cabinet to get the sound off the stage, while allowing you (and your band mates) to hear you too.. This is most definitely a small venue perspective on my part based upon the types of places I've played in and are likely to play in the future. The open back combo is well suited for smaller venues for this reason as well. It's also less likely to get the club owner who's standing by the back wall listening while you warm up to yell, "too loud."

It's not that I don't like closed back cabinets. I think they sound very good in the right application, but they are very directional. In a large venue they're great for projecting the sound to the back of the room (or maybe I should say "hall"). They have a big focused sound that ensures that you cut through the mix and get down range. I mean, who doesn't love the sound of a cranked Marshall stack with closed back cabinets? It's just a little impractical for most of us small time musicians. Even in a large venue an open back cabinet can be miked through the PA system. If it's a large venue, you can bet that you'll be using a substantially large PA system too. There are limited fixes for the directional sound problem like beam blockers, but they'e somewhat of a band aid fix.

Finally, there's the problem with speaker break-up in a closed back cabinet. With all of the pressure that is generated in a closed back cab, the speaker cones don't move as much as in an open back cab. The speaker remains tighter and there's less of a break-up effect until higher volumes are reached. Not good in a small club.

So, the reasons for my choice are practical for me. At one time when I was much younger I favored closed back cabinets. One of the first good amps I ever played through was a Bandmaster with a closed back 2X12 cabinet. I thought that was the coolest thing. And besides, I never saw Hendrix up on stage with a Pro Reverb or a Vibrolux :cool: .

Time and experience do change one's mind though. So it has with me.

BTW Leonidas, My Valve Jr. sounds great through the 2-Weber C12N's in my semi-open back cabinet. Loud, punchy and warm.

Oh yeah, to answer your question Spudman, I favor the 2X12 combination. It adds depth and dimension that the 1X12 doesn't have. The same is true to a greater extent with the 4X12, but that's like hauling a coffin around.

A 2X10" can also have a great vibe with the right amp circuit and speakers. Again it has more depth and dimension than a single speaker.

[fender tele]

I have a Super, which is obviously an open-backed combo. I have toyed w/the idea of getting either a 2 x 12 or a 1 x 15 ext cabinet to run with it, but with the band I front now, it;s not necessary. I'm the only guitar player. (keys, bass, drums, me)

If you mic your amp through a p.a., & you have enough channels on the p.a. board, one little "trick" (that's actually decades old) is to mic the front of the amp as normal, & then stick another mic in the back of the amp. I've actually just laid a mic down right in the back of the amp & it worked great. You might even find by doing this & mixing the channels that you put the "front" mic right on the cone. There's a LOT of low end that comes out the back of a combo. I would be doing this, but I'm down to one sm57 at the moment.

[Spudman]

I found an informative article on the subject of heads, combo's and cabinets. Check it out.
http://www99.epinions.com/content_2668404868

[Nelskie]

One thing I'd like to add from past experience is power handling. With a little amp like the 5w Valve Jr., I think the best sound will come from the lowest rated speaker (as long as it's a quality speaker) that you can load in the cab. E.G.- A pair of 20w Celestions will sound much better than a pair of 200w E.V.s. The lower rated speakers will move the air better and give more of the aforementioned "WHUMP"!
That's an interesting point, oldguy, and one that I'll probably need to revisit later on down the road when I decide to get something in the way of a cabinet together for my Valve Jr. head. Right now, I run it through a single 12" closed-back Peavey 112E, with an Eminence Swamp Thang, and though it sounds pretty good, it seems to be missing a little bit of that "whump" you've described. The Eminence speaker has a huge mongo ceramic magnet on it, too, and is rated for something like a bazillion watts - so when considering your point, it makes perfect sense. A speaker with a lower wattage rating probably would make best use of a lower watt signal, and ultimately, produce a better, more defined sound. The Swamp Thang, to me, appears to be designed to provide a good base for thundering brimstone, and players who push mountains of power behind their rig. In other words, its not particularly well-suited for a little 5W Class A rig. Anyways - good thread, guys. Lots of good information. ;)

PS - oldguy: what's a 200W E.V.s? Just curious. Is that the abbreviated name of the speaker.

[Robert]

I think he means Electro-Voice speakers (E.V.).

[TS808]

So Blooz...

Which cabinet do you think work better for an open backed combo amp? An open backed 1x12, 2x12, closed backed 1x12 or 2x12? I'm limiting the choices because the reason we have combo's is so we don't have to pay a roadie to lug our 4x12's around.

Certainly some combination should be optimal in conjunction with an open backed combo? I don't think this has specifically been addressed yet. Which do you or anyone else think is the "holy grail" for additional sound?

Just from personal experience...I owned a Peavey Classic 30 a while back (probably 10 years ago) and I bought the closed-back extension cab for it. The combination of the open backed Classic 30 and closed back classic 30 extension cab gave it a pretty good "mix" or balance.

[tot_Ou_tard]

If anyone wants to turn their combo into the brain for a multi-cab beast--including the choice to engage or disengage the combo's internal speaker. There are the Speaker Mate Combo Expanders from Sherlock Audio in Canada. Apparently, the speakers can have different impedence characteristics.
There are several different versions from $80-$92.50 depending on how many cabs you want to drive.
www.sherlockaudio.ca

[Leonidas]

Wow tons of great info everyone!

Which of course leads me to more questions :D

How does the speaker's total watts factor in to the whole thing? I know oldguy had mentioned earlier that if you are using a lower output head, then it would be smarter to use a lower wattage speaker in your cab. Now, what is considered "low", and how exactly would you match up the watts from a head (such as 5w for the valve jr) to the total watts of the speakers in the cab? Also, is it possible to have too many watts being put into a lower watt speaker? (Like a 50 watt head into a 20w speaker) Could you blow them out?

Thanks again everyone.

[Cranium]

I was also wondering if it possible to use like a 30w speaker with a 50w amp?

[Bloozcat]

Well it would seem reasonable that a speaker that was rated for, say 150 watts would have a stiffer cone and voice coil, as well as a large magnet. If this is done as part of the design requirement to handle higher wattage amps, then it would also seem reasonable that there would be a minimum amount of wattage to drive the speaker to it's optimum performance. There is uaually a minimun wattage necessary to drive a speaker efficiently.

Many people, amp makers and musicians alike, favor the ratio of twice the wattage rating for the speaker(s) as the output of the amp. I don't think that there's any real theoretical evidence to justify this ratio, yet it's heard often. So by this measure, a 50watt amp should have a speaker (or speakers) capable of handling 100watts. By the same ratio then, our little Valve Jr.'s only "need" a 10watt speaker. Now, having run my Valve Jr. through my 50 watt 2X12 cabinet with the Weber C12N's, I can tell you that the little 5 watt amp drives those speakers just fine. There's definitely not the same punch or presence that I get with my 40watt bandmaster through those same speakers, yet the Valve Jr. still sounds pretty good. Of course, there is no justifiable comparrison between the Bandmaster circuit and the Valve Jr. either.

One of these days I'd like to experiment with different speakers in a single speaker cabinet for the Valve Jr. The lowest wattage single speaker I have is a Mojotone MP10R Alnico at 30 watts. That speaker might work out well, but I'd love to hear a 15 or 20 watt speaker for comparison. I have a sneaking suspicion that the lower wattage speaker would be better suited for the 5 watt amp. That's just speculation on my part, but I'll tell you that my 50 watt C12N Weber 2x12 cabinet sounds extremely good with my 40 watt Bandmaster head.

For the record, it is inadvisable to exceed the voltage rating of your speaker(s) with your amp. A dimed 50 watt amp could easily blow a speaker rated for 30 watts. I once asked Ted Weber about using my C12N's (rated at 50watts/pair) with a 50 watt amp I had. Even though it's pretty well known that Ted's ratings on his speakers are on the conservative side, he still said that he wouldn't recommend it. He said that if I dimed the amp that I would be right on the edge and there was the possibility that the speakers could blow. If pedals were used, it was almost assured that the speakers would go.

[Cranium]

Well Eric Johnson uses 30w G12H speakers with a 50w plexi head and Jimi Hendrix also used G12M/H speakers from 20-30w with a 100w head so unless it has something to do with using 4x12 cabs then Im a little confused!?

[TS808]

Wow tons of great info everyone!

Which of course leads me to more questions :D

How does the speaker's total watts factor in to the whole thing? I know oldguy had mentioned earlier that if you are using a lower output head, then it would be smarter to use a lower wattage speaker in your cab. Now, what is considered "low", and how exactly would you match up the watts from a head (such as 5w for the valve jr) to the total watts of the speakers in the cab? Also, is it possible to have too many watts being put into a lower watt speaker? (Like a 50 watt head into a 20w speaker) Could you blow them out?

Thanks again everyone.

A lower wattage speaker will "break up" or distort better than say, a 150 watt speaker through a 50-watt amp. On the opposite, putting a 50-watt speaker into a 150 watt amp will blow your speaker.

My suggestion would be to match up the speaker to the amp as best you can. A low watt speaker through a higher watt amp will distort tone too much and you run the risk of blowing out the speaker.

I had an old Peavey Bravo (a 15-watt all tube amp) many years ago and the speaker was rated low. It was cool just to see the speaker actually moving and thumping on high settings.

[Bloozcat]

Well Eric Johnson uses 30w G12H speakers with a 50w plexi head and Jimi Hendrix also used G12M/H speakers from 20-30w with a 100w head so unless it has something to do with using 4x12 cabs then Im a little confused!?

Cranium,

When you use more than one speaker wired together in a cabinet, you're spreading the input wattage between the multiple speakers. If Eric Johnson is using a 2X12 cabinet loaded with G12H30's, then the cabinet can safely handle up to 60 watts. 120 watts if it's a 4X12 cabinet with the same speakers.

Hendrix often used stacks (2-4X12 cabinets per head), so he was well within the 100 watt output of the amplifier at 240 watts handling capability of the two 4X12 cabinets. Even if a single 4X12 cabinet was used with one 100 watt head, there would still be a 20 watt safety margin.