Help needed to understand Ohms with split bass cab

[FinnDave]

The Ashdown ABMs are good amps. I'm currently using an ABM600 (with a Rootmaster 800 as a back-up, or if I'm too lazy to carry the heavier ABM!) and they go through either a Barefaced Super Compact (1x12) or Super Twin (2x12). 

The Super Compact is an 8 ohm cab, so I'm getting about 350w from the ABM or about 500w from the Rootmaster. I always use the 1x12 for pub gigs, and the volume  has never needed to above about 1/3. Like you, my pub bands don't put anything through the PA except vocals (and sometimes the bass drum). For larger gigs, I prefer to use the 2x12, so have the full power of the amp available, but again, have never needed to use more than about 1/3 volume. The 2x12 is then basically an on-stage monitor for me & the band as the bass is DI'd into the venue's PA.

Two 1x12s would be a better bet for me, really, but I bought my Super Twin a few years ago, and the 1x12 only last year. I don't want to sell my Super Twin, so I'm stuck with more cab than I really need hanging around the house between gigs. Luckily, I have an understanding wife!

[Dragonlord]

38 minutes ago, Fingers McGee said:

Thanks everyone. Was a bit nervous with it being my first post, but I’m really great full for the sound advice and for everyone going easy on me

So I’ll need to have a chat with the guys in the band as we joint own the PA, but I’m still thinking of updating my rig. I’ve had the Ampeg for around 10yrs, although I love the sound of the amp. I also really like the sound of Ashdowns And they’re in my price range. So, with that being said, what would be your recommendations on the following gear: 

- Ashdown ABM EVO IV 600 Watt Bass Amplifier Head 

- Ashdown ABM 900 Watt EVO III Bass Anplifier Head

both these heads are the same price, but the 600w is a newer spec

speakers:

- Ashdown ABM 410H 4x10 Bass Cab

- Ashdown ABM-210H 300w 2x10 Compact Bass Ca

- Ashdown ABM-115H Compact EVO IV Bass Cabinet 

so, for example, would the 600w head, combined with the 2x10 cab and 1x15 can be best, or would the 900w and 4x10 cab be the way to go? From what I understand of everyone’s comments, doing something like the 2x10, 1x15 and 900w would be a no go as I would be pushing too much through that set up

whats everyone’s thoughts, please?

 

I wouldn't worry about "pushing too much" - that's why you have a volume knob! It comes down to what sounds best to you and how many (and how heavy) cabs you are comfortable carrying. But only you can answer those questions. Either a 410 or a 210+115 should be plenty to cover pretty much anything. The 210+115 (or 210+210) would give you a modular setup so that you could only bring one to rehearsals and small gigs. Still, if you love your amp, as you say, be careful because you might end up giving a lot of money and in the end being happier with your previous setup. New isn't always better!

[bazzbass]

are you always using your PA or do you play venues with house PAs? If the latter, use it to experiment with going thru the PA via a DI AND use your amp basically for you and the drummer to hear as a monitor.. You may not need to buy anything

[Fingers McGee]

50 minutes ago, bazzbass said:

are you always using your PA or do you play venues with house PAs? If the latter, use it to experiment with going thru the PA via a DI AND use your amp basically for you and the drummer to hear as a monitor.. You may not need to buy anything

No. We have our own PA but it doesn’t have any bass bins. Hence why I play straight from the amp

[bazzbass]

Not having subs is not a problem, too much goes thru them anyway causing horrible boominess.

It's more about EQ Not having drums through it helps you a lot. Make sure the guitars and voice have a high pass filter at around the 600 to 1000Hz mark (I think iirc) so they don't creep into your sphere and put a high pass filter on your bass at 80 to 100 Hz so the speakers are not trying to pump out the low lows that might damage them and use up more energy from them than you think.

Start off conservatively thru the PA, turning your amp down as you put more through the PA to spread the load.

Edited August 11, 2018 by bazzbass

[Phil Starr]

I think that the PA is an issue best dealt with separately. It's much better to go through the PA for all sorts of technical reasons and good PA has come down so much in price it is probably cheaper to have modest backline  and good PA than the other way round. However, (can you tell I was a science teacher) I still maintain backline good enough to be able to run without PA support for flexibility.

First of all don't worry about the extra 300W. It'll only give you 1dB of extra volume, that's the smallest change in volume a human can detect. Our hearing isn't linear, it's very sensitive to quiet sounds for obvious evolutionary reasons and protected against very loud sounds so we have the maximum range available to us. The downside of that is you need to double power to get a meaningful increase in volume of 3dB. In practice a 200W amp is enough to do almost any gig if you have typical speakers. You could buy a Transit to transport that flatpack home from IKEA but they pretty much always fit in the back of your car. In this case either amp will be more powerful than you strictly need.

Choose your speakers on the basis of which ones sound best, then get enough of them to be loud enough is the best advice.

Mixing speakers is fine but problematic. The character/timbre of the speakers doesn't come from the bass for the main part but the mids and if you look at speaker frequency plots they usually have plenty of bumps and dips. When you mix them you'll have no idea if those peaks align and emphasise each other or align with a dip and cancel. The combination will sound very different from the speakers on their own, that's if they are equally loud. If they have different efficiencies then one speaker may dominate and the other be little heard rendering it into an expensive stand to sit the other one on. If you own loads of speakers then trying them out with each other is fun and you may hit lucky but it isn't a sensible thing to plan on doing from the start. Two 12's,  two 15's, two 2x10's will all be plenty and in reality you'll end up taking one to a lot of gigs on it's own. Don't choose on size though choose on sound. 

[Fingers McGee]

Cool. So, if I don’t want to keep my current set up and go for the ashdowns, I should be looking at 600w head with either

- 1 4x10 cab,

- 2 2x10 cabs or a

- 2x10 with a 1x15. Is this right?

maybe I was going too far in regards to the 900w

[Lozz196]

Out of the two amps listed I`d go for the ABM 600 EVO IV - it`s an amazing amp, incredibly flexible eq, very loud with a good presence. Re cabs, well I`m all about the easy life and I find one relatively heavy ABM 410 with good castors on it is pretty easy to move about.

[Fingers McGee]

5 minutes ago, Lozz196 said:

Out of the two amps listed I`d go for the ABM 600 EVO IV - it`s an amazing amp, incredibly flexible eq, very loud with a good presence. Re cabs, well I`m all about the easy life and I find one relatively heavy ABM 410 with good castors on it is pretty easy to move about.

I think I’m sold on the 600w then. But what would be the difference between having only the 4x10 and a mixture of 2x10 and/or 1x15 (obviously it’d be less gear to carry) but would there be a difference in volume/power? - I get there will be a tone difference

[Lozz196]

1 minute ago, Fingers McGee said:

I think I’m sold on the 600w then. But what would be the difference between having only the 4x10 and a mixture of 2x10 and/or 1x15 (obviously it’d be less gear to carry) but would there be a difference in volume/power? - I get there will be a tone difference

There would maybe be a tone difference to having two seperate cabs which are more than likely voiced differently, though I`m sure with the flexibility of the eq on the ABM600 you could easily get the same sound as the 410 as with the 210/115. I`m not sure about volume/power - I`m yet to have to push the amp  for volume on some pretty big stages when connected to the 410. I`ve also had it connected to two 115s and there wasn`t much difference in my regular settings.

[bazzbass]

the problem with mixing cabs is that the 210 will get the same power as the 115 cab. the two 10s will only have half the power of the single 15. This is not ideal and is why a lot of people recommend two identical cabs.

two 210 cabs stacked vertically is really good,especially to hear yourself as the speakers are closer to your ears

[DBerriff]

Playing in a wedding band is the fun part. Setting up and breaking down the rig are the necessary evils. Venues I played in ranged from a posh private school to a wet, muddy field on the side of a hill. Splitting the speakers to 2 identical units splits the weight and can make the carry in and out a lot easier for an old man like me. Trolleys and/or castors do not work on every surface, and they cannot manage stairs or steps (think wet, slippery fire escapes).

For most gigs a single good 12" or 2 x 10" will do the job. Two cabs when you really want the volume. You have the flexibility to decide.

I am not discounting the PA solution by the way ; it was just that our band's PA was not up to job so I have less experience. When we did have a good PA to play through it was superb, with or without bass bins, and one cab was plenty.

Edited August 12, 2018 by DBerriff

[Fingers McGee]

So what would be the difference between using 2 2x10 speakers, which are 300w each, and using the 4x10 can which is 675w, with a 600w head? Aside from the obvious such as size and transport etc.

2 2x10 cabs will cost more than the 4x10

Edited August 12, 2018 by Fingers McGee

[Sweeneythebass]

18 minutes ago, Fingers McGee said:

So what would be the difference between using 2 2x10 speakers, which are 300w each, and using the 4x10 can which is 675w, with a 600w head? Aside from the obvious such as size and transport etc.

2 2x10 cabs will cost more than the 4x10

Someone correct me if I’m wrong but they’re will be very little difference between 2 210’s and one 410. The biggest benefit from the 210’s will be flexibility (small rig /big rig)

But remember the ohms! What are the ohm ratings on the cabs?

If the 410 is an 8ohm cab you’ll get roughly half your wattage (300w) and the 210’s are 8 ohm (each cab, total load 4 ohm) you’ll get the full 600w from your head.

[Fingers McGee]

1 hour ago, Sweeneythebass said:

Someone correct me if I’m wrong but they’re will be very little difference between 2 210’s and one 410. The biggest benefit from the 210’s will be flexibility (small rig /big rig)

But remember the ohms! What are the ohm ratings on the cabs?

If the 410 is an 8ohm cab you’ll get roughly half your wattage (300w) and the 210’s are 8 ohm (each cab, total load 4 ohm) you’ll get the full 600w from your head.

I’ve just checked the website and the 4x10 is 8ohms and a single 2x10 can is also 8ohms

so does that mean to get maxiumunwattage from 600w head, I should go with the 2 2x10’s?

Edited August 12, 2018 by Fingers McGee

[Hellzero]

Strangely, one thing that nobody mentioned is the fact that low frequencies will be heard far away when high frequencies will be very closer. It's the main problem when using your own amp to spread your sound all around the venue. You won't hear yourself playing when everybody in the room will hear an ugly muddy bass sound...

If you want to hear yourself on stage, use your speaker(s) at the height of your ears or slightly below and decoupled from the ground, because of the bass effect. To hear yourself, you only need to have a mid sound, which is the opposite of most EQ's I've seen on stage...

As I told it earlier and as @Phil Starr clearly mentioned it, the increase in power referring to Watts is almost negligible, in fact to really double the power of a 200 Watts amp, you'll need to have around 10 times the  power to double it... Impressive, no ?

And yes, you'll have the maximum power with the 4x10 + 2x10 in 8 Ohms each, which means 4 Ohms in parallel.

Edited August 12, 2018 by Hellzero
Mentioned

[Dragonlord]

6 hours ago, bazzbass said:

the problem with mixing cabs is that the 210 will get the same power as the 115 cab. the two 10s will only have half the power of the single 15. This is not ideal and is why a lot of people recommend two identical cabs.

two 210 cabs stacked vertically is really good,especially to hear yourself as the speakers are closer to your ears

That's not such a big problem as a 210 has around the same cone area as a 115. That's why a 210+115 is usually a better match than a 410+115.

@Fingers McGee, yep, that's right. One thing you must understand is that the wattage on the cabs is more like tolerance levels (as in "safe up to 300W"), the output comes from the amp. So with an amp that is 600W@4ohm, yeah, you'll be getting all of it with two 8ohm cabs, and if they're rated at 300W each it should be a fine match. With an 8ohm cab, even if it's rated at 1000W, you'll be getting what your amp puts out at 8ohm (if it's 600W@4ohm, it will usually be around 300-350W@8ohm).

[Fingers McGee]

Thanks guys. So I think I’m decided on going for the 600w head with 2 2x10 cabs. We had a gig last night where I discussed all your advice with the band and we’re gonna look at investing in improving our 850w PA. 

one last question on this (I hope - and btw, thank you to everyone who helped with this. It’s definiately given me a better understanding of all this watts and ohms malarkey) whilst we work on upgrading the PA, would the aforementioned combo of 2 2x10’s be sufficient to fill a modest size venue? With my current amp, I can hear myself on stage ok. It’s more about getting the bass volume out in conjunction with the PA

thanks 

Edited August 12, 2018 by Fingers McGee

[Hellzero]

9 minutes ago, Fingers McGee said:

Thanks guys. So I think I’m decided on going for the 600w head with 2 2x10 cabs. We had a gig last night where I discussed all your advice with the band and we’re gonna look at investing in improving our 850w PA. 

one last question on this (I hope - and btw, thank you to everyone who helped with this. It’s definiately given me a better understanding of all this watts and ohms malarkey) whilst we work on upgrading the PA, would the aforementioned combo of 2 2x10’s be sufficient to fill a modest size venue? With my current amp, I can hear myself on stage ok. It’s more about getting the bass volume out in conjunction with the PA

thanks 

Read 2 posts earlier.

I would go the PA path for all the band and keep your actual combo used at stage volume and if you don't hear what you are all playing, don't play louder, do the opposite.

Always start with the drummer playing first, then add your bass to create a clear and audible mix, then the guitar(s), the keyboard(s) and the vocal(s) and never try to compete, but to complement the frequencies of all instruments. Doing this way, you'll be amazed how low you'll be playing and easily heard. It's all about compromise and ego.

[Fingers McGee]

8 minutes ago, Hellzero said:

Read 2 posts earlier.

I would go the PA path for all the band and keep your actual combo used at stage volume and if you don't hear what you are all playing, don't play louder, do the opposite.

Always start with the drummer playing first, then add your bass to create a clear and audible mix, then the guitar(s), the keyboard(s) and the vocal(s) and never try to compete, but to complement the frequencies of all instruments. Doing this way, you'll be amazed how low you'll be playing and easily heard. It's all about compromise and ego.

Good shout. Thank you 👍

[Sweeneythebass]

I’m considering selling my rig 

GB STreamliner 600

barefaced 210.

Loud enough for almost any gig and great EQ

if you’ve the budget a 210 Barefaced @ 4ohms with the head your talking about will be more than adequate

[chris_b]

4 hours ago, Fingers McGee said:

So what would be the difference between using 2 2x10 speakers, which are 300w each, and using the 4x10 can which is 675w, with a 600w head? Aside from the obvious such as size and transport etc.

That's a "What have the Romans ever done for us!" moment.

The beauty of 2 210's is they are smaller and easier to transport.

So you can chose how many cabs are appropriate for the gig. They are lighter to carry and you don't have to sit there in front of a 410 on a small quiet gig. If you have another cab, ie a 115 or 112 you can mix and match with one of your 210's (yes, you can do this).

[itsmedunc]

On 10/08/2018 at 12:23, Fingers McGee said:

Thanks for the advice everyone. It seems that I might be focusing on the wrong area and need to consider using our PA more. My worry is that I could blow the speakers up as we only have 2 speakers on stands, we don’t have any bass bins on the floor (currently, the drums are not mic’d up either). This was based upon some advice a sound engineer gave me years ago - putting the bass through the speakers youbpce on stands could blow up the speaker. Is this correct?

 

Having read the whole thread, I find myself confused too! Am I right in thinking that your existing combo can compete with the un-mic'd drum kit onstage? If not, upgrade. If so, I would have thought that the problem lies in another area. If the drums and bass have good level mix together then, apart from environmental factors, I would look at EQ (previously mentioned) and then at the levels of the other members. I've used a 1x10 combo pushing around 200w for onstage monitoring with PA support for years and never had a problem. Well, apart from with a guitarist who likes to play at Shay Stadium levels down the local pub. 

If you can all get a good level in rehearsals (be honest with the others about their levels), you should be able to do that as your onstage monitoring mix. That is your starting point. Then move onto what folk hear out front. Many guitarists whack their volume up as it's a bigger venue but as they are going through the PA too, there is really no need. If this is the case, you are competing against the onstage volume and then the PA. No wonder the bass gets 'lost' in this scenario. By boosting your volume to "fix" the problem you will more than likely get a 'mushy' overall sound and give yourself and others tinnitus. Danger that an already loud guitarist will turn up more too. 😂 

If you sort the above out and you still can't be heard FOH then look at having the bass going through the PA too. If the onstage levels are good, you may well find that the PA speakers (depending on their spec) will take a bit of bass. Failing that (in order of cost), try adding a 2x10 to your setup (spread the sound a bit not the volume) or add a pair of decent active PA cabs to the existing PA setup. This could help you far more than replacing your bass gear. The beauty of adding active PA cabs is that, with a preamp you can use them as a pretty impressive bass rig if needed. They will have lots of other uses too (there's a huge thread about FRFR setups on here).

Whereabouts are you? I'm sure a local BC'er would be more than willing to help you out if you needed to try an extension cab out.

I haven't even mentioned Ohms! 

 

[Phil Starr]

4 hours ago, Fingers McGee said:

So what would be the difference between using 2 2x10 speakers, which are 300w each, and using the 4x10 can which is 675w, with a 600w head? Aside from the obvious such as size and transport etc.

2 2x10 cabs will cost more than the 4x10

A single 2x10 will probably be loud enough for 90% of your gigs, so if you buy a 4x10 you'll be carrying a lot of hardware for no reason 90% of the time. For bigger gigs you might want a second cab but all your eq will remain the same, just plug it in and you'll have the same sound but louder. Stacked vertically two of the cabs will place the top speaker at roughly ear level so you will hear it more clearly than a 4x10. Having a vertical line of speakers will spread the mids in a flat wide fan of sound so all your audience will hear the same sort of sound. A traditional 4x10 tends to beam the sound like a guitarist's cab  so people off access get less of your sound.

 

I'd repeat though that you ought to go and try some cabs if at all possible, including lifting them of course. 

 

Itsmedunc has made some good points, if you are in the north west near the land of 4000 potholes then take up that offer, if you are down anywhere near Somerset I'll lend you an extension cab. There'll probably be a helpful basschatter somewhere near you.

[lownote]

I'm not that experienced or knowledgeable so perhaps shouldn't be sticking my head over the parapet.  But strikes me you must be playing Wembley if you need those size cabs and amp power.  I play a Markbass 500w head into a 1x12 cab 8 ohm (so giving me only 350w) and playing quite large pub gigs I've never had the gain over midday on the dial.  Also, how young are you and your back?  You'll find it a lot easier to carry a couple of light but quality small cabs than a 410/12 or 1x15 dinosaur.   

Edited August 12, 2018 by lownote12