Stacks

[mint_bass]

ok i need some help
 
i am looking to get my first stack and am confused by a few things and some help would be great
 
1 if i buy an amp head unit the speaker cabinet needs to beable to hanle the power so if the head is 300watts the cabinet has to beable to handle 300watts if thats right what difference would it make if say i got a 300watt head and a cabinet that could handle 1000watt would that be a bad idea would this effect the output in any way?
 
2. what is a speakon conection
 
3 if i am only going to buy one cabinet what configeration would you recommend ie 4x10 etc i realise this has a lot to do with the sound you are after i play a lot of slap and a lot of fast fingerstyle what do you think
 
any help would b great thanks
andrew

[mint_bass]

also does the material used to construct the cones make a huge difference ie paper or metal thanks

[stoney]

The best advice I can give to you is to go to a music store where you can audition several amps/cabs AND trust their personnel.
 
Simple answers to your questions:
1. A 1000w cabinet will suck the life out of your poor little 300w amp, perhaps buning it out because the cabinet will constantly be looking for more power. Try, for example, a cabinet rated at 200 watts for a 300 watt amp.
 
2. A Speakon cable is one that will physically attach to the amp and the cabinet. They can be wired to run bi-amp etc.  In general, if you have to use a speakon cable, make sure you carry a spare because if it dies, you're out of luck. You can use speakon adaptors and 1/4 inch plugs.  
 
3. Can't really comment on the speaker configuration but I think you're heading down the right path.
 
good luck

[rogertvr]

I use a Trace Elliot 250w head, with two Trace Elliot cabinets (can't remember their wattage, sorry - I think they're 200w each). They are a 1 x 15 and a 4 x 10 (neither have horns).
 
The 1 x 15 produces the full bottom AND most of the ring at the top end. The 15 allows a decent bass response without it sounding soggy.
 
The 4 x 10 doesn't have much in the way of bottom or top end, but it does have a massive mid-range and an extremely percussive response.
 
If I use only one cabinet, I go with the 4 x 10 because of the response available from smaller speakers and the graphic on the head can make up most of the lost bottom and top end.
 
I chose this configuration in 1986 after seeing Mark King, he was using the same configuration doubled-up with a 500w head.  I was amazed that  the confirguration leant itself to playing with the fingers and slapping...
 
...so I went for the same thing but only half the size. I lends itself to a whole range of sounds and playing styles if my experience of it is anything to go by.
 
Hope this helps!
 
Rog

[David Houck]

1 - I agree with Stoney; it's probably not a good idea to match a 300 watt head with a 1,000 watt cab.  The head and cab should be fairly well matched.
 
2 - There are three common speaker cab connectors; quarter inch phone jacks, banana plugs, and speakon.  It is said that banana plugs and speakon connectors provide greater electrical integrity than phone jacks, and that in high power systems phone jacks will not pass as much power to the speakers.  As Stoney mentioned, the speakon connectors lock in place and are more secure; and as he also mentioned, speakon connectors can be wired for biamping.
 
3 - The difference between a 410 and a 210 made by the same builder is often not so much tone as output and weight.  As a generalization, the 410 is going to put out more sound than the 210.  If you are playing in a loud band or on a large stage, a single 210 might not cut it.  If someone else carries and sets up your rig for you, weight isn't going to be a factor.  For me, weight is a big factor; I would much rather make two trips to the car for a pair of 210s than lug around a single 410.  But then I'm older now than I was when I used to carry at least two 410s to every show.  Where difference in tone between cabs of the same builder is more significant is between say a 410 and a 215.  If your style is a lot of slap and a lot of fast fingerstyle then as a generalization I would think the 410 more appropriate since the smaller cone size gives a faster response.

[xlrogue6]

I think maybe Dave and Stoney are confusing power rating and efficiency ratings for cab matching purposes.  Standard practice is to use a cabinet that will handle more power than your head puts out, thus avoiding speaker failure when pushing the limits.  The power rating of the cabinet makes no difference to the head.  What *does* make a difference is the efficiency of the cabinet--i.e., how much acoustic output you get for watts in.  Acme cabinets, for example, are relatively inefficient and require lots o' watts.  In general, buy a cabinet that is rated for at least the same RMS power as your amp puts out.  A cabinet rated higher than your amp will not suck the life out of the amp, unless it is Acme-like in its efficiency, or lack thereof.
 
The main reason that I prefer Speakons to 1/4 connectors is that their contact area is much larger than the tip of a 1/4 jack, thus allowing better power transfer.  Admittedly, this is only a factor at higher power levels, but still, if you're picky enough to play an Alembic, you might as well do the speaker connections in the most effective way possible, IMO.
 
Speaker configuration is more and ear call than anything.  Personally, I like smaller drivers (10's until I acquired my GenzBenz 212 with Neodymium drivers) for everything but the bottom octave, where 15's and/or 18's can't be beat.  I don't like the midrange character of the larger drivers, which is why my large rig is biamped, crossover at 70-100 Hz, depending on venue and volume.  Ported 410's (e.g., the Ampeg 410HLF)tend to have a somewhat exaggerated yet (to my ears) artificial sounding bottom end.

[hollis]

Well, now I'm way more confused than usual...and that's saying something!
 
It has always been my understanding that what Dave and Stoney were saying is indeed correct.
I think that it's a lot easier to blow both amps and speakers if you are under powered.  The reason(I think) this is so is because of the tendancy of under powered amplifiers to be over driven into a clipping mode.  It is my understanding that clipping is when sine waves are pushed past there peak causing them to square off.  Also, I have always thought that square waves double the output exponentially, thus causing fried voice coils..
 
Oh hell, this explains it better than I:
   
Clipping  
 
Amplifier distortion occurring when a high energy wave form (a very loud sound resulting in a large output) is input into an amplifier and the amplifier is unable to fully reproduce it due to power supply limitations or amplifier design limitations resulting in the audio output waves being cut off (the rounded tops sliced off resulting in short waves with flat tops). Clipping creates audible distortion and can be damaging to speakers especially if the clipping is hard and frequent.  
 
Clipping generally occurs when an amplifier is playing at a high level and it is asked to output a large amplitude waveform (tall wave with lots of power). The amplifier clips when it does not have the power capability to correctly create the waveform. Instead, as the wave is built it hits a ceiling essentially not allowing the wave to go any higher. Since the amplifier cannot recreate the remaining portion of the wave rising above the ceiling, the wave is cut off.  
 
Generally, the more power an amplifier has (especially relating to the quality of the amplifier's power supply) the more immune it is to clipping. For this reason, larger amplifiers tend to provide better quality sound at loud listening levels since they clip less often (if at all) compared to similar but less powerful amplifiers.  
 
Clipping may be heard in loudspeakers as an abnormal, non-musical sound. It is unpleasant and it may damage speakers (with tweeters being particularly susceptible). This occurs because a speaker cannot produce the flat-topped waveform sent to it by the clipping amplifier.  
 
In order avoid clipping, do not play a sound system at excessively loud levels and make sure the amplifiers being used are large enough to recreate the sound levels in the given space. Generally, use the largest amplifiers reasonable, as they are less likely to clip and damage speakers. It is much more dangerous to clip loudspeakers by using a small amplifier lacking in power than to use a large amplifier even if that amplifier's power ratings are greater than those recommended for a given speaker (distortion, and clipping in particular, causes damage not clean power from a quality amplifier).
 
I take this to mean: Don't overdrive your amplifier.  The easiest way to avoid this problem, and to have the most clarity at higher levels is to have an amplifier with sufficient power to easily push whatever speakers ou use.
 
Or........Maybe I'm mistaken.
 
 
 
 

[bsee]

No doubt, clipping amps kill speakers.  Let's back up a step though.  Why a stack?  I owned one many years ago when I thought it was cool, but it didn't result in a better sound, for me or the band.  Age and experience have taught me that a good quality combo amp provides all the stage volume most of us are ever going to need.  A Super Redhead, for example.  If the band needs to be heard by more people than that can support, you can add a large-diameter extension speaker or send the direct out to the PA.
 
If you're sold on the idea of a stack, then go for the approximately matching head and cabs, but make sure it has enough juice that you can run it around half volume.  You're not going to clip the power amp if you keep the knobs set at reasonable levels.
 
As a guy who has been there and done that, I can tell you that it's a lot more fun to pack up a Super Redhead after a gig than it is to move a 6-space rack and two big cabinets.  If you're an Alembic electronics fan, you can also mount your SF-2 right into the Super Redhead's available space.
 
Just my opinion...

[811952]

I used to go through speakers fairly often when I was using matched speaker/amp combinations.  Now I use as much power as I can get (currently 600 watts x 2 for the big stuff) and haven't blown anything in years.  This is much more critical for high frequency drivers, as the square wave from clipping a quick transient will kill 'em dead in a flash.  The not-always-obvious part of the entire equation is that even though I use gobs of power, I still play at reasonable volumes.  Bsee has a good point too.  For a time I played though a couple of dedicated floor monitors for pitch and presence and relied on the p.a. for bottom and was pretty content.  Stoney's advice about simply playing through as many setups as you can is the wisest advice I can offer.  When building your own system, it usually works pretty well to emulate others whose sound you like...
John

[David Houck]

Kent; while I can't speak for Stoney, I would suggest that rather than being confused, perhaps in our desire to be brief we just weren't being entirely clear.  The following is copied from
http://www.bassbacke.de/hints/bass/cabproperties.htm
I don't know anything about this author, but I found his page doing a quick search on the subject.  I'm including it here since it is on point and essentially says what I think Stoney and I were getting at and what I've heard from various sources over time.  I've only copied a portion of the page; those who want to read more may wish to follow the link.
__________________________
 
Amps should have more power than speakers can handle.  Often people think their speakers should be capable of handling more power than the amp driving them. Their logic is that if the speakers can handle more, the amp can't hurt the speakers. Nice try. It's only working if you stay well below the maximum rated output of such an amp.
 
As soon as you drive an amp beyond it's maximum power rating, it goes into clipping which can end in nasty DC which will fry even the biggest speaker cab.
 
In short: small amps can easily kill even a speaker made for more power if driven too hard.
 
What about amps with more power than a speaker can handle? Simple. Don't drive them to their limits and they will bring your speaker cabs up to their full power with little or no risk. Even if you drive a speaker at a little more power than it's designed for it will handle it much more gracefully than any clipping amp.
 
So how much more power should one have? There are very different opinions out there. Some say add 50% of the speaker cab power rating, some aim for twice the power.
 

[dnburgess]

To add to the comments re Andrew's original points:
 
1. Speaker and amplifier power
I second John's advice re amplfier power and speakers - there is no such thing as too much headroom when it comes to amplifier power. Paradoxically you are far more likely to damage speakers by having an amplifier that has too little power than one that has too much.
 
For example, the rule of thumb with Acme speakers is to use an amplifier that is rated at twice the continuous power rating of the speaker.  
 
The perceived loudness of a speaker is related to its sensitivity (how efficiently it converts electrical energy into sound) and power capacity by the following mathematical relationship:
 
Om = (10 x log Pm) +S1, where
 
Om = maximum output  
Pm = maximum input power  
S1 = sensitivity measured at one Watt/one meter
 
Its wrong to think of a speaker sucking power from an amplifier. Rather the amplifier pitches and the speaker catches. So using a small amp with an inefficient speaker to practice in your bedroom won't necessarily cause any harm. The risk is when you try to crank up the amp to play loud and it starts to clip.
 
2. Speakon connectors
The Speakon is a twist lock connector which forms a much stronger physical connection than 1/4 or banana plug - i.e. can't be pulled out accidentally.
 
Most importantly though, the design of the Speakon is such that its virtually impossible to temporarily short the amp if plugging in the speaker with the amp. switched on. (not recommended). Whereas both 1/4 and banana plugs are relatively easy to short - which can damage the amp, if switched on.
 
3. Speaker configuration
A number of manufacturers (e.g. Acme, Accugroove) have taken a hi-fi approach to bass speaker design, so its now possible to get great sound from smaller, lighter boxes. But there is a general trade off between small size, bottom end and efficiency such that you can have two out of three. Assuming that, as a bass player, bottom end is a must - the major design choice is between small less efficient systems and larger more efficient ones. With the prices of good quality high powered amplifiers falling in line with electronics prices generally, most people prefer to throw more power at smaller lighter speakers.

[kevin_k]

I AM CURRENTLY RUNNING ONE OF MY BAGEND 18'S THAT DESIGNED TO HANDLE 300W @ 8OHMS WITH MY QSC 1602 BRIDGE/MONO.
 
BASICALLY MY AMP IS CAPABLE OF 1000W @ 8 OHMS IN BRIDGE /MONO.  I HAVE MORE THEN TRIPLED THE AMOUNT REQUIRED BY THE SPEAKER, BUT IT SOUNDS GOOD.  I DON'T TURN THE GAIN UP PAST 22 AND I KEEP THE F1-X VOLUME AT 5-6.  NO PROBLEMS SO FAR.  
 
DON'T WORRY, I'LL LET EVERYONE KNOW IF I DO BLOW THE SPEAKER.  

[xlrogue6]

Good page, and hopefully clears up any confusion I may have caused.  The speakers can't pull excessive power from an amp, thereby causing clipping and/or Magic Smoke--only the operator can do that!  Beware of Nigel Tufnel syndrome!

[hollis]

I'm glad to find that not everything I know is wrong.

[adriaan]

Let's not forget you can also make yourself heard a lot better by asking everyone not to play so loud. Easier on the ears too.