2x10 Build - couple of questions and driver recommendations?

[doninphi]

Hi folks. I've been making bass cabs up. I've made a 1x15" so far with a Celestion BN15-300X - a little trial and error on the dampening inside and 3d printing my own ports to tune it. So far I'm really happy with it.

 

I've started and made the cab for a 2x10 too. But got nervous before ordering the planned 2x BN10-200X to match the other cab sound wise (as I feel happy with the clear tone I like of the BN15.)

 

So the cab details:

MDF 14mm (then clad in recycled pallet wood 8mm thick, so they look cool and rustic (I'll link a pic)

External box sizes:

56.5h

45w

36d

 

2 x 10 BN10-200x 8ohm, but happy to take other ideas on this. But their details:

10"

7.7cm mounting depth

3.5cm magnet depth

 

The cab calculates as an internal cu/ft of: 2.5314

 

I haven't cut ports yet, but can drill and 3d print to suit. I rear ported last time and plan to do the same. 

 

Pic is my 1x15 with the 2x10 cab on top. I hope you like them  

Bass is my quick pick up Washburn, my 5st Sire M7 is in another room. So  the cab needs to be tuned to handle the low B  

 

Thoughts greatly appreciated. 

Thanks

Phil

 

Edit: Oh and forgot to add, I'll be making it up as a series/parallel setup, via a cable, to make the pair 8ohm overall to work with my mini Warwick Head. Tho if I like playing one at practice and the other cab at home, I might re-wire to a different setup. For now though, I'd like to try both at once. Although I know people say 1x15 and 2x10 or 4x10 can cause odd waveforms. I'm happy to experience it and see before I settle on using 1, or both cabs.  I also love the head, and might upgrade to the 600w Warwick one at some point. 

 

Edited 16 hours ago by doninphi

[Bill Fitzmaurice]

What software are you using to come up with the design? And what criteria to choose the drivers? For simple ported or sealed cabs I use WinISD 0.7.  I consider not only frequency response but also sensitivity, maximum power (determined by Pe and Xmax, whichever is lower), and port velocity (no more than 20m/s at full power within the nominal passband). I choose drivers based on their cost effectiveness while producing the desired results. Also note that software is only effective within the region of pure pistonic function, which is roughly two octaves above Fs. Above that you must use the driver data sheet SPL chart. And that only gives you the raw numbers. Turning those into a cabinet design relies mainly on experience to know what works best. 

 

As for mixing drivers, it's like a box of chocolates: you never know what you're going to get. Sticking with one insures that you will know. I ignore when people say that 'this 115 and that 410 work a treat', because virtually any two speakers together will work better than either on their own. The only way to know if any given pair of mismatched cabs/drivers work better than two of each matched is to try all three combinations side by side. That's fine if you have two of each, but if you don't it's an experiment you can't undertake. 

 

Don't sweat tuning for the low B note. While the fundamental is 31 Hz the bulk of the content is in the 2nd and 3rd harmonics, 62 and 93 Hz. No one ever complained about an Ampeg Fridge handling low B, and its F3 is 58 Hz. I never tune bass cabs lower than 45 Hz. I only go lower than that for PA subs. 

Edited 15 hours ago by Bill Fitzmaurice

[doninphi]

17 minutes ago, Bill Fitzmaurice said:

What software are you using to come up with the design? And what criteria to choose the drivers? For simple ported or sealed cabs I use WinISD 0.7.  I consider not only frequency response but also sensitivity, maximum power (determined by Pe and Xmax, whichever is lower), and port velocity (no more than 20m/s at full power within the nominal passband). I choose drivers based on their cost effectiveness while producing the desired results. Also note that software is only effective within the region of pure pistonic function, which is roughly two octaves above Fs. Above that you must use the driver data sheet SPL chart. And that only gives you the raw numbers. Turning those into a cabinet design relies mainly on experience to know what works best. 

 

As for mixing drivers, it's like a box of chocolates: you never know what you're going to get. Sticking with one insures that you will know. I ignore when people say that 'this 115 and that 410 work a treat', because virtually any two speakers together will work better than either on their own. The only way to know if any given pair of mismatched cabs/drivers work better than two of each matched is to try all three combinations side by side. That's fine if you have two of each, but if you don't it's an experiment you can't undertake. 

 

Don't sweat tuning for the low B note. While the fundamental is 31 Hz the bulk of the content is in the 2nd and 3rd harmonics, 62 and 93 Hz. No one ever complained about an Ampeg Fridge handling low B, and its F3 is 58 Hz. I never tune bass cabs lower than 45 Hz. I only go lower than that for PA subs. 

 

Hi mate. Thanks for the reply. 

 

To make the first 1x15 I chose the driver and used Internet calculators to make the cab basing it off a mark bass 1x15. As it was compact etc... The Internet calculators are OK for basic stuff.

 

For this one I tried again to do the same but although I got some bits out I cant help thinking they aren't as good for 2 x speaker cabs where the details of a 1xspeaker cab numbers go into them well.  The 1x15 is proof of that pudding as I'm happy with it but can't help thinking my luck might run out in the 2x10

 

Is there any chance you can pop my numbers into your software? I can't install that as it's a work laptop. See if you thjnk 2x bn10 200x 8 ohm will suit or if i need to hunt a different spec speaker? I'd really appreciate it. 

 

If I have to take the punt. I will haha. 

 

A 70ltr volume should be OK. I'll just mess with the port ideas till it sounds right. But your input might save me a lot of faff. 

 

Thanks

Phil 

 

 

[Bill Fitzmaurice]

They model best in a 70 liter box with port area of 200 sq.cm. and length of 25cm. The box volume is net, not including the volume taken up by the port and the drivers. The main limiting factor is the 4mm xmax, which limits input power to only 100w per driver at 70Hz, which is in the middle of the critical 2nd/3rd harmonic region. A driver with 5mm or more would be better. If you have two cabs the xmax should suffice. 

[Downunderwonder]

The other consideration is the impedance load you put on your amp.

 

Two 8 ohm 10's is an unlikely pairing with a single 15 so I am wondering what you are up to.

[Downunderwonder]

Having a HPF [high pass filter] in your preamp chain makes handling low B a lot easier. Cutting out the pesky low fundamentals allows your amp eq to work on the juicy stuff.

[doninphi]

1 hour ago, Downunderwonder said:

The other consideration is the impedance load you put on your amp.

 

Two 8 ohm 10's is an unlikely pairing with a single 15 so I am wondering what you are up to.

 

Using a series&parallel setup I can get 8 ohm overall. So the two cabs will br wired differently with a cable which makes this happen between them. This head has only 1 output. I'll need to rewire if I go to the bigger head later. 

[doninphi]

3 hours ago, Bill Fitzmaurice said:

They model best in a 70 liter box with port area of 200 sq.cm. and length of 25cm. The box volume is net, not including the volume taken up by the port and the drivers. The main limiting factor is the 4mm xmax, which limits input power to only 100w per driver at 70Hz, which is in the middle of the critical 2nd/3rd harmonic region. A driver with 5mm or more would be better. If you have two cabs the xmax should suffice. 

So perhaps 2 ports? 

 

The 100w limit at 70hz I guess will make a quiet spot in the range of the cab? 

 

Not the worst then. Ill see if I can find some different drivers with a better vmax 

 

Thank you

[doninphi]

Over Double the weight. But the pulse XL has a Xmax of 8mm

 

Better?

 

https://celestion.com/product/pulse-xl-10-20/

[Beer of the Bass]

I'm sure I remember seeing specific cautions about running dissimilar speakers in series. I don't recall what the precise issue was, but it would seem to be a quite complex situation with the impedance curves of the different speakers interacting and likely quite hard to anticipate how it will behave. 

[Downunderwonder]

26 minutes ago, Beer of the Bass said:

I'm sure I remember seeing specific cautions about running dissimilar speakers in series. I don't recall what the precise issue was, but it would seem to be a quite complex situation with the impedance curves of the different speakers interacting and likely quite hard to anticipate how it will behave. 

True.

[doninphi]

Well if it lunches the amp. I'll have a reason to buy the 600w one! 

 

How do people run 1x15 and 4x10 cabs then impedance wise? 

 

I'm actually planning to have a cab at home. And a cab at practice. They will rarely actually be played together. But I appreciate the comments. I'll bear it in mind. I only wanted a 10" cab as I've never had one. Only ever had 15s.

 

What I'll actually end up with is 2 x 4ohm cabs. One for each place I need one. A specially made cable will make them run in the parallel series way. I guess realistically I'd only need them both for large venues. 

Edited 1 hour ago by doninphi

[doninphi]

This was the page I calculated the ohms

 

https://soundcertified.com/speaker-ohms-calculator/#3_Series-parallel_and_other_wiring_types

 

It explains I'm OK as long as I'm between 4 and 8.

 

I guess what you're saying is the setup will create different impedance at differing volumes/watts depending on load. 

 

The Gnome amp can take between 4 and 8 ohm. So would it be best to set the cabs to 8ohm overall. As if I go higher ohm you lose power but I'm under the impression that it won't damage an amp.  Whereas if I go below 4 ohm I could. 

 

I don't know enough about the curves to predict. Is there a link to where you read this so I can gain an insight? 

 

Thanks 

[doninphi]

This page seems to explain that impedence gets higher mostly. 

 

https://audiojudgement.com/speaker-impedance-curve-explained/

 

There example of a 4 ohm speaker reaching as low as 3.4 and as high as 50. High will limit power and not damage an amp. Low would result in damage. So i feel I am safest heading for 8 ohm. So if the 3 speakers have low points in hz. I'd be low chance of dropping below 4ohm.

 

Am I barking up the wrong tree? 

[doninphi]

15 speaker. First pic

 

10 speaker. Second pic

 

Both impedence curves show their worst impact will be the low B kinda area. E upwards looks closer to the nominal. 

[doninphi]

If I take the lowest ohm value stated and put them all in the calc. I appear to be 6 ohm. Which is still in the safe area for the amp. 

 

You'll all probably correct me now but that's fine. Still reading and learning.

[Beer of the Bass]

It could still do some screwy things even without stressing the amp. At the frequency where one speaker has an impedance peak, the signal voltage across the other speaker will drop so that it has very little output, which has got to sound weird. 

[doninphi]

Graphs look pretty similar to me. But I take your point. 

 

Like I say. Will rarely be a stack anyway.