Daisy chaining cabs with different ohms & cones

[bumnote]

5 hours ago, Al Krow said:

It's very much my point about: "Well if that were true then a 5" speaker should be able to match an 18" speaker no problem. But we all know that's rubbish, so clearly there is a gradation here, right?"

Take a listen to Phil Jones cab. They have 5" dia speakers

[chris_b]

1 hour ago, Al Krow said:

There's a reason that cab manufacturers have landed on 10" and 12" speakers as generally providing the best "platform" overall, and that woofers tend to be 15" or larger. 

Again, not true. There are all sizes of drivers and multiples of them. These are all designed and used in conjunction with the aims of the designer. If you think a 15" driver is the way to get low end, you're thinking is out by 30 years.

[Al Krow]

Just now, chris_b said:

...your thinking is out by 30 years.

Lol! - I think you've just hit the nail on the head! Guess it's what happens when you take a break from music for over two decades 😂

Ok so:

1) Pairing an 8ohm cab with a 4ohm cab is sub optimal, as the 8ohm cab will only get 1/3 of the power from the amp (if the amp has a single speaker output);

2) Adding a 15" isn't going to deliver any benefit to getting low end compared to a 2x10";

3) I'd best tell my BC buddy who was very kindly going to do me really good deal on his VK115 that my fellow BCers have just saved me a wad of cash...  ;

Who says BC doesn't save you money (well at least 1/3 of the time)?! 😂

[LukeFRC]

23 minutes ago, Al Krow said:

Lol! - I think you've just hit the nail on the head! Guess it's what happens when you take a break from music for over two decades 😂

Ok so:

1) Pairing an 8ohm cab with a 4ohm cab is sub optimal, as the 8ohm cab will only get 1/3 of the power from the amp (if the amp has a single speaker output);

2) Adding a 15" isn't going to deliver any benefit to getting low end compared to a 2x10";

3) I'd best tell my BC buddy who was very kindly going to do me really good deal on his VK115 that my fellow BCers have just saved me a wad of cash...  ;

Who says BC doesn't save you money (well at least 1/3 of the time)?! 😂

1) probably - this wouldn’t be a problem if you had a 1x12 and a 2x12 as each driver would probably be getting the same. 

2)er I’ll leave that one for @Bill Fitzmaurice...

3) oh don’t worry, the Gas will come get you....

[Bill Fitzmaurice]

7 minutes ago, LukeFRC said:

2)er I’ll leave that one for @Bill Fitzmaurice...

That depends on the 210 and the 115. But mixing a 210 with a 115/6 opens up more cans of worms best left undisturbed.

[Al Krow]

20 minutes ago, Bill Fitzmaurice said:

That depends on the 210 and the 115. But mixing a 210 with a 115/6 opens up more cans of worms best left undisturbed.

Never been that keen on worms. Except in the garden. 

[chris_b]

6 hours ago, Al Krow said:

Lol! - I think you've just hit the nail on the head! Guess it's what happens when you take a break from music for over two decades 😂

Ok so:

1) Pairing an 8ohm cab with a 4ohm cab is sub optimal, as the 8ohm cab will only get 1/3 of the power from the amp (if the amp has a single speaker output);

2) Adding a 15" isn't going to deliver any benefit to getting low end compared to a 2x10";

3) I'd best tell my BC buddy who was very kindly going to do me really good deal on his VK115 that my fellow BCers have just saved me a wad of cash...  ;

Who says BC doesn't save you money (well at least 1/3 of the time)?! 😂

1) You can pair 8 ohm and 4 ohm cabs. I do with my BF 110 and 210 and in the past with a Berg 112 and 212. If you do that they work very well.

2) Stop generalising. As others have said. . . depends on the cabs in question.

3) Call Vanderkley and ask them. They know their cabs better than anyone.

Edited October 29, 2018 by chris_b

[Phil Starr]

22 hours ago, LukeFRC said:

You’re not being told that size doesn’t matter, you’re being told that there isn’t a link between size and frequency response. 

Hi Al, this is right as you have noted. Beyond this it get's more complex where a number of factors come into play all at once, I'm more than happy to bore the pants off everyone but it's not likely to solve your practical problem of what to buy

The practical observation is that two 10's have roughly the same cone area as a 15, everything else being equal it means they might well be equally capable of making loud bass, that will depend on which 2x10 or 15 you choose.

The problem with mixing speakers is that you'll end up with something that isn't the sound of the 15 or the 10, and what you get isn't easy to predict. That becomes even more so if the speakers are different ohms and one is taking twice the power of the other. you've probably got a 50/50 chance of getting a sound which is 'more bassy' and even less of a chance of getting something you like. It's like throwing two dice when the one you've already thrown is a six. It isn't wrong but it could be an expensive gamble unless you can try out the combination you crave.

 

[jacko]

I found this website to be very useful when trying to figure out the best impedance for speakers..

http://www.bcae1.com/spkrmlti.htm  

 

[Al Krow]

3 hours ago, Phil Starr said:

Hi Al, this is right as you have noted. Beyond this it get's more complex where a number of factors come into play all at once, I'm more than happy to bore the pants off everyone but it's not likely to solve your practical problem of what to buy

The practical observation is that two 10's have roughly the same cone area as a 15, everything else being equal it means they might well be equally capable of making loud bass, that will depend on which 2x10 or 15 you choose.

The problem with mixing speakers is that you'll end up with something that isn't the sound of the 15 or the 10, and what you get isn't easy to predict. That becomes even more so if the speakers are different ohms and one is taking twice the power of the other. you've probably got a 50/50 chance of getting a sound which is 'more bassy' and even less of a chance of getting something you like. It's like throwing two dice when the one you've already thrown is a six. It isn't wrong but it could be an expensive gamble unless you can try out the combination you crave.

Phil, as ever, very nicely put thank you.

So when manufacturers put in a mix of cone sizes into a single cab e.g. a 15" and a 6" ("to deliver punchier mids") I presume they have done extensive research to get their cabs "just so" so they work really well and it's much more hit and miss when your average punter like me is trying to mix and match?

Combination speaker sizes can be found in VK 115 (15 + 6) and the Markbass 123 (12 + 5) and I'm sure there are a number of others.

Edited October 30, 2018 by Al Krow

[LukeFRC]

44 minutes ago, Al Krow said:

Phil, as ever, very nicely put thank you.

So when manufacturers put in a mix of cone sizes into a single cab e.g. a 15" and a 6" ("to deliver punchier mids") I presume they have done extensive research to get their cabs "just so" so they work really well and it's much more hit and miss when your average punter like me is trying to mix and match?

Combination speaker sizes can be found in VK 115 (15 + 6) and the Markbass 123 (12 + 5) and I'm sure there are a number of others.

They will be using a crossover inside the cab to split the frequency to different drivers. It will be designed to work together - so for example the mids won’t go to the bass driver and the bass won’t blow the mid driver up. 

If you match, say a 1x15 and a 1x8 they both will be getting the same signal 

[chris_b]

47 minutes ago, Al Krow said:

So when manufacturers put in a mix of cone sizes into a single cab e.g. a 15" and a 6" ("to deliver punchier mids") I presume they have done extensive research to get their cabs "just so" so they work really well and it's much more hit and miss when your average punter like me is trying to mix and match?

They will probably have done a lot of work on designing and building a crossover so that the right frequencies are delivered to the correct drivers.

If a "punter" puts 2 cabs together they will both be working with the whole signal so if there are mismatches in the drivers that might be apparent in the sound. With a good crossover the different drivers should fit together like a jigsaw, because they will be handling different frequencies.

 

snap!

Edited October 30, 2018 by chris_b

[Al Krow]

...and the assumption is therefore that manufacturers assume that punters will either be getting a single cab or at most two identical cabs; and they're therefore not trying to get the crossovers to work when different cabs (e.g. 15" and 10") are mixed and matched because there are only so many variables they can fix?

[LukeFRC]

47 minutes ago, Al Krow said:

...and the assumption is therefore that manufacturers assume that punters will either be getting a single cab or at most two identical cabs; and they're therefore not trying to get the crossovers to work when different cabs (e.g. 15" and 10") are mixed and matched because there are only so many variables they can fix?

I think some manufacturers want you to keep buying more cabs of differing styles, mix them up with all sorts of phasing problems, at different points off axis, get frustrated read bass forums sell them and buy new ones - and then repeat every few years

[Phil Starr]

17 hours ago, Al Krow said:

Phil, as ever, very nicely put thank you.

So when manufacturers put in a mix of cone sizes into a single cab e.g. a 15" and a 6" ("to deliver punchier mids") I presume they have done extensive research to get their cabs "just so" so they work really well and it's much more hit and miss when your average punter like me is trying to mix and match?

Combination speaker sizes can be found in VK 115 (15 + 6) and the Markbass 123 (12 + 5) and I'm sure there are a number of others.

15+6 is a classic combination, the idea of using a small speaker is quite a good one. It isn't necessarily to shape the mids, though it does allow that possibility but there are two good other reasons to use a small speaker. Large speakers cause cancellation problems when their size becomes close to a wavelength long. Straight on is good but when you stand to one side (or more probably above your speaker as a bassist) the sound from one edge of the cone arrives at your ears fractionally after the sound from the other edge and you get cancellation. What that all means is that mid frequencies are harder for you to hear and everything is a bit woolly and muddled, not good for your playing. Using a smaller speaker raises the frequency at which that happens and you will hear yourself better. The other advantage is that a lighter cone will move more quickly and will track your sound better at higher frequencies reducing distortion and making it easier to engineer something with a flat response.

The advantage over a horn is that this small speaker will handle a lot more power and will allow a lower crossover frequency.

One of the designs whose concept I really like is the Genzler  12-3 https://www.genzleramplification.com/shop/bass-array12-3/ 

The 3" drivers will go higher than a 5" driver (and higher than anything that comes out of a bass pickup) and having an array of four will shape mid/treble dispersion nicely. More GAS

[mcnach]

On 29/10/2018 at 11:18, Al Krow said:

In short, better lows.

But is it really the case that larger speaker cone size makes no difference whatsoever, other things being equal?

It's very much my point about: "Well if that were true then a 5" speaker should be able to match an 18" speaker no problem. But we all know that's rubbish, so clearly there is a gradation here, right?"

 

The 18" is likely louder because it's bigger but the whole frequency thing depends on the box too, and 15" = better lows is just BS. There are 15" cabs that are bass-central and others very middy... and you won't say an 810 lacks lows, right?

If you get another identical 210, you won't have to consider how the different speakers interact dur to having different responses... you'll get the same but louder and with better low end... and both cabs will receive the same amount of power. 

 

edit: I didn't realise this thread had ran for days already...  sorry for the useless reiteration

Edited November 4, 2018 by mcnach

[Bill Fitzmaurice]

On 30/10/2018 at 14:31, Al Krow said:

So when manufacturers put in a mix of cone sizes into a single cab e.g. a 15" and a 6" ("to deliver punchier mids") I presume they have done extensive research to get their cabs "just so" so they work really well

Since we're still on this subject, no, you shouldn't presume that. For every manufacturer that does the required research another just tosses drivers into a box.

Quote

But is it really the case that larger speaker cone size makes no difference whatsoever, other things being equal?

The only factor determined by cone size in and of itself is the dispersion angle. It goes smaller as frequency goes higher, based on the size of the cone relative to the wavelength produced. To keep dispersion as uniform as possible as the wavelengths get shorter the cone size must get smaller. That, and that alone, is why midrange drivers are smaller than woofers, and tweeters are smaller than midranges. Of course the driver T/S specs and other pertinent features are optimized for the driver pass band, but those are secondary concerns, as no matter how well optimized they're of no use if the cone size is too large for the pass band to be heard other than directly in front of the driver.

[Al Krow]

Right as luck would have it(!) a "rare as hen's teeth" 4ohm Vanderkley 15"+6" cab has just come onto the market, and for a good price.

So the complication of combining two cabs of different ohms with 2/3 of the output going to the 4ohm cab and 1/3 to the 8 ohm cab disappears.

It's then just a question of whether a 156 will mesh nicely with a 210.

I'm getting a pretty strong steer from my more expert BC'ers that if I was going to add another cab I'd be better off adding another 210 rather than mixing a 156 with a 210 - anyone disagree? 

Be worth my dropping Mark VK a quick email to get his considered views on the subject too.

[Bill Fitzmaurice]

The combination might work fine. It might not. There's no way anyone can tell you what the result will be. The only valid method of comparison would be to have the 210 plus 15/6 and the 2x210 side by side. Otherwise it's all pure speculation.

[LukeFRC]

4 hours ago, Al Krow said:

Right as luck would have it(!) a "rare as hen's teeth" 4ohm Vanderkley 15"+6" cab has just come onto the market, and for a good price.

So the complication of combining two cabs of different ohms with 2/3 of the output going to the 4ohm cab and 1/3 to the 8 ohm cab disappears.

It's then just a question of whether a 156 will mesh nicely with a 210.

I'm getting a pretty strong steer from my more expert BC'ers that if I was going to add another cab I'd be better off adding another 210 rather than mixing a 156 with a 210 - anyone disagree? 

Be worth my dropping Mark VK a quick email to get his considered views on the subject too.

If it’s a good enough price that you can move it on if it doesn’t work out, and if you can afford it, then just go for it! 

[Al Krow]

15 hours ago, LukeFRC said:

If it’s a good enough price that you can move it on if it doesn’t work out, and if you can afford it, then just go for it! 

I've dropped Mark Vanderkley a line to see what he recommends in terms of combining different speakers in the range or adding another 2x10. If he's cool with the combination, I'll definitely consider taking the plunge. Just waiting to hear back from someone looking to buy a Mesa PH212 off me... 

While I'm waiting for Mark to get back to me with his thoughts, a Q of a more general nature:

Frequency response and low end

I know that folk are saying that cone size, by itself, has nothing to do with how much "low end" a cab will put out; but I would have thought that freq response would make a significant difference (and I guess I was subconsciously using cone size as a proxy for freq response with my initial comments, as those numbers were at the back of my mind). E.g. if:

Cab1 is 45Hz to 16kHz

Cab2 is 40Hz to 16kHz

Cab3 (15") is 39Hz to 10kHz

and all from the same manufacturer / general same spec etc. I'd be expecting Cab1 to be the "brightest" of the three and Cab3 to have the most "low end" because that is how it has been set up in terms of frequency response?

Fyi - I've actually taken 3 real life examples here from the VK range, being the VK210MNT, the VK210LNT an the VK115MN6.

And my own experience, having owned Cabs 1 & 2, was that Cab1 was indeed brighter than Cab2. Was that just coincidence or exactly what we would expect by following the frequency response numbers?

If we go one step further and take:

Cab4 (15") 25Hz to 2khz from another well known manufacturer who positively recommends putting this under his 1x12 and 2x10 cabs to get more low end and states "don't worry about crossover, they blend really well". 

@Bill Fitzmaurice @Phil Starr and other experts on this thread - views please?

Edited November 5, 2018 by Al Krow

[Phil Starr]

Hi Al, it's genuinely complex isn't it?

One of the complexities is that a lot of the 'information' is also advertising. For example your 'well known manufacturer' who is quoting a 15" cab running from 25-2k is probably stretching things a little. If the 15 is flat down to 25 Hz and can handle any power it will have to have a very heavy cone and a long throw, both of which would make it very inefficient. More likely it is 10-20dB down at 25 Hz so it is making some sort of sound but just not loud enough for you to hear significantly. The 1x12 may sound good with their 2x10 but if one part of their claim is improbable can you believe anything they say? A speaker that only goes to 2k wouldn't be suitable for bass on it's own.

All this means is that you couldn't tell anything about how the cab would sound just from a bald 45-16k frequency response. Is that at -3dB, -10dB or some other figure. Is the response flat between those two extremes or biased towards some frequencies more than others. Add in one more factor, how we perceive sound. It is just like everything else to do with our senses, an entirely subjective experience. What we think of as bass is often about what is going on elsewhere. If I'm trying to pick out a bass line from a recording I usually cut the mids and tops rather than boost the bass. That'll make the bass line stand out much better than boosting bass 95% of the time. If your cab 2 had a bit of a mid/top end boost it would sound brighter even if the bass end was exactly the same. It might not be the 5Hz quoted difference in 'cut off' that creates the difference but what both cabs are doing in the 100-200Hz range that you are hearing.

The best way of judging any cab, particularly an instrument cab is by ear. Test gear will help anyone designing a cab but you can't really drag it along to a music shop. Published figures without any indication of how they are measured aren't always a lot of use. I'm not completely cynical about manufacturers but it's a tough world for them too. If they use 'honest' rms watts and +/- 3dB frequency figures and so on then they are likely to lose sales to people who use peak figures.

I'll get back to you on what in principle might be the difference you'd hear if the figures were independently measured and so could be compared, that's another long story. 

[Bill Fitzmaurice]

14 hours ago, Al Krow said:

Cab1 is 45Hz to 16kHz

Cab2 is 40Hz to 16kHz

Cab3 (15") is 39Hz to 10kHz

@Bill Fitzmaurice
@Phil Starr

Insufficient data. Only by seeing a measured SPL chart can you know what's really going on. If only manufacturers posted them, but none do.

 

 

[Chienmortbb]

It is hard not to get technical but cone size does matter. It is just that it is one of a number of things that matter.

[Al Krow]

4 hours ago, Chienmortbb said:

It is hard not to get technical but cone size does matter. It is just that it is one of a number of things that matter.

Glad to get confirmation that I wasn't going totally loopy on this

Where have you been all my thread? 😄 

Edited November 5, 2018 by Al Krow