Lightweight Sub-Woofers

[Downunderwonder]

38 minutes ago, Chienmortbb said:

To me, and it is my opinion only, the scarcity of Rolls products in the UK, price and the fact that it needs an external PSU, would rule this out for me , especially as it is many times more expensive. 

I got mine from Parts Express in the US. Any little 12V PSU will do. From memory around 50 GBP.

[Happy Jack]

As of right now (and I suspect it will be gone by lunchtime):

 

https://www.ebay.co.uk/itm/236374724127

[Phil Starr]

13 hours ago, synthaside said:

It Sounds like I should probably pick up a used crossover ...  perhaps you could point me in the direction of something suitable , ideally smaller rather than bigger ....  I really was looking to avoid ending up hauling a rack around  with the next pickup being "proper"  Active Tops 
 

Yeah I think planning your next System is a great idea. It is much better to know where you are going as it informs your purchases rather than rushing into cheap fixes that only last a few weeks before needing the next bodge. I've spent a lot of money early on making do when a more measured approach would have saved a bit of money in the long run. I learned loads by making mistakes though  That's why I applaud your current solution. It lets you get on with playing music whilst you plan something better. I used to have a Stagepas 300 and that and the 500 aren't really good for a band, they just struggle for volume. the 400/600 were much better. They are good for monitors though as the sound is pretty good with no nasties to cause feedback issues. You don't need them to go so loud as monitors.

 

If you do go for a crossover I wouldn't worry too much about the brand, Behringer are the most widely available https://www.thomann.co.uk/behringer_cx2310_v2.htm

 but there are lots of other OEM products that are essentially similar. Used ones are curently £35-50 on Marketplace but at £77 a new one might be worthwhile depending upon how tight funds are. You'll get £35-50 if you upgrade so it'll cost you £30ish for indefinite 'hire'.

 

If you want small then there is this. It's programmable and 24db/octave filters are available on all four channels. You've also got limiting so you could program in some protection for your tops. Harder to sell on when you've finished with it though as it is a more techie solution

 

https://www.thomann.co.uk/the_t.racks_dsp_4x4_mini.htm

 

[synthaside]

1 hour ago, Happy Jack said:

As of right now (and I suspect it will be gone by lunchtime):

 

https://www.ebay.co.uk/itm/236374724127

Now who would go and do that ay ...

Cough ....  this is exactly what i was looking for as i want to avoid Rack gear and  it looks simply enough conceptually would you look at that its fallen off ebay ... 

Now ... I guess i have to decide what  at frequency im crossing .... perhaps because its running to a dedicated  bass amp rather than a sub it should shoot a little higher to 100 /120 rather than 80 ?

Edited Thursday at 09:27 by synthaside

[Al Krow]

4 hours ago, synthaside said:

Now who would go and do that ay ...

Cough ....  this is exactly what i was looking for as i want to avoid Rack gear and  it looks simply enough conceptually would you look at that its fallen off ebay ... 

Now ... I guess i have to decide what  at frequency im crossing .... perhaps because its running to a dedicated  bass amp rather than a sub it should shoot a little higher to 100 /120 rather than 80 ?

 

Nice one! 

 

Well given that one of the reasons for having a sub is to take load off the tops, be interested if there's any reason not to cross over at say 150Hz, and you can get some bass as well as your kick handled by the combo?

 

Wished I'd used this crossover set up when I had a MB Alain Caron, which has excellent speaker excursion for a bass combo, with my RCF 310A tops. And ideally combined with the IEMs my crew are using today to avoid needing monitors. 

 

Tbf probably would have beem no better than the pair of RCF 932As which we're using currently and overall a comparable outlay.

[Chienmortbb]

On 09/10/2025 at 10:21, synthaside said:

Now who would go and do that ay ...

Cough ....  this is exactly what i was looking for as i want to avoid Rack gear and  it looks simply enough conceptually would you look at that its fallen off ebay ... 

Now ... I guess i have to decide what  at frequency im crossing .... perhaps because its running to a dedicated  bass amp rather than a sub it should shoot a little higher to 100 /120 rather than 80 ?

I would usually set the crossover frequency to 100 with a standard sub. It’s a good starting point. 
 

As far as the Thomann crossover does, I have the one with the power amps in but the software is the same. It looks a bit old fashioned, think Win 3 meets Win 95 but it is clear and easy to use. 

[Al Krow]

18 hours ago, Chienmortbb said:

I would usually set the crossover frequency to 100 with a standard sub. It’s a good starting point. 
 

As far as the Thomann crossover does, I have the one with the power amps in but the software is the same. It looks a bit old fashioned, think Win 3 meets Win 95 but it is clear and easy to use. 

 

Totally agree with a standard sub, which often don't go much higher anyway.

 

But was wondering whether it might make sense to flex this to make more use of the bass combo's ability to handle higher frequencies?

Edited yesterday at 13:15 by Al Krow

[Chienmortbb]

I would not do that, let the PA tops do what they are designed for and cut off as though it was a normal sub. The important thing is to be able to invert  the sub output to match the tops. The Thomann DSP crossover allows this. Of course it also allows you to experiment. 

[Al Krow]

18 hours ago, Chienmortbb said:

I would not do that, let the PA tops do what they are designed for and cut off as though it was a normal sub. The important thing is to be able to invert  the sub output to match the tops. The Thomann DSP crossover allows this. Of course it also allows you to experiment. 

 

It's an interesting one, 'cos there's an argument that tops are completely fine with going down to 60Hz? So why cross at 100Hz?

 

I'm definitely no expert here, but if a key purpose is to relieve the tops of their low end lows to focus on non-bass frequencies, then crossing over at 150Hz (because the bass combo can easily handle up to this) would be more beneficial than 100Hz. But, as I say, I'm no expert!

[synthaside]

Considering our tops are probably the weakest part of the chain I want to take as much load from them as i can ,there's also a little bit of element of encouragement to  me making this setup  work because the singer went out and bought the PA , and hauls it to gigs  ( a singer has arrived with more than a microphone)  Making them /it work until the bands takings can fund something cool new and shiny feels better to me even if i could just splurge on something myself i'm already hauling more than enough. 

She couldn't have foreseen that the rest of the band would start the journey towards ampless  ... A 400 watt Yammy Stagepass a good enough vocal only PA when you arent pumping all and sundry into it.

[JPJ]

3 hours ago, Al Krow said:

 

It's an interesting one, 'cos there's an argument that tops are completely fine with going down to 60Hz? So why cross at 100Hz?

They may go down to 60Hz but the power will drop. Some speakers quote -3dB some even as low as -6dB for their low end figure. Personally, I cross over at between 80Hz and 100Hz depending on the system.

Edited 11 hours ago by JPJ

[Bill Fitzmaurice]

7 hours ago, Al Krow said:

 

It's an interesting one, 'cos there's an argument that tops are completely fine with going down to 60Hz? So why cross at 100Hz?!

Because the sub probably has more available output from 60-100Hz than the tops. Crossing lower than 100Hz with tops that are on stands also brings floor bounce cancellation into the equation. 

Quote

crossing over at 150Hz (because the bass combo can easily handle up to this) would be more beneficial than 100Hz.

No, as that results in directionally locatable frequencies coming from the subs. Then you lose the ability to put the subs anywhere, which should never be below the mains unless there's no alternative. 

[Al Krow]

41 minutes ago, Bill Fitzmaurice said:

...which should never be below the mains unless there's no alternative. 

 

Seems to be the key point here, thanks. Please remind us why that is Bill - sound reinforcement from the walls?

 

42 minutes ago, Bill Fitzmaurice said:

[Cross over at 150 Hz]...results in directionally locatable frequencies coming from the subs. Then you lose the ability to put the subs anywhere...

 

I suspect 8/10 pub / bar bands in the UK put their tops on poles above their subs due to space limitation issues. But if the only downside is directionally locatable frequencies and bands aren't fussed about the losing the ability to put subs anywhere, then no particular problems crossing over at a higher frequency than the usual 100Hz when using a bass combo as a sub?

[Chienmortbb]

One of the things that annoys me, apart from my terrible bass playing, is speaker manufacturers specs. 
 

We have heard many times how the maximum SPl is often inflated by 6dB but many well respected brands will quote, as said above, their frequency responses at -6dB, indeed some quote is at -10dB. Some, RCF for example, do not even quote the limits. 
 

Wharfedale Pro quote their speakers at both -3dB and -10dB so you can compare. It is likely that if no limits are specified it is -10dB. 
 

So a Top that is quoted at say 65Hz as its lower frequency limit may well be -10dB down, a huge amount. By crossing over at say 100Hz, you ensure that the Tops can handle the parts of the spectrum that they were really designed for, the section where they. Really have a flat response. 

[Bill Fitzmaurice]

3 hours ago, Al Krow said:

 

Seems to be the key point here, thanks. Please remind us why that is Bill - sound reinforcement from the walls?

Allison Effect, the cancellation from the reflection off the rear wall. To prevent it the subs must be close to the wall, the mains far from it. When both are the same distance away it's unavoidable. 

 

Quote

I suspect 8/10 pub / bar bands in the UK put their tops on poles above their subs due to space limitation issues. But if the only downside is directionally locatable frequencies and bands aren't fussed about the losing the ability to put subs anywhere, then no particular problems crossing over at a higher frequency than the usual 100Hz when using a bass combo as a sub?

See above. Since you can put the sub anywhere that relieves some of the space concerns. By dint of using a bass combo as a sub it is a sub, and the same placement rules apply.