Subwoofer to pair with RCF art312-a mkIV?

[BadBrainz]

Good Afternoon,
I have today purchased a pair of RCF 312's and would like to add some low end to my setup. I have a tight budget of around £500 for an active subwoofer. I play reggae/Punk/D&B.

I have been looking at the:

DB Technologies Sub615

Turbosound ip15b

Alto TS315s

Does anybody have experience of these subs? Or have any other suggestions around my budget? Would also consider an 18".

I am a novice when it comes to PA systems. Im putting something together for personal use. Parties with family/friends.

Many Thanks

[Sam Spoons]

You will need a sub with HPF outputs as the Art 312 does not have a built in HPF*

What is your budget? The obvious choice is to go for a an RCF sub, maybe the 705 AS-II**

* It used to be that all subs had the crossover built in and you fed the tops from the sub, these days the practice seems to be to include an HPF in the tops and subs just have the LPF and a link out. This is a little more flexible from a wiring POV but you need to be sure the HPF in the top and LPF in the sub match both WRT crossover frequency and slope. Having them both in the sub avoids the possible mismatch.

** https://www.bax-shop.co.uk/active-subwoofer/rcf-sub-705-as-ii-active-subwoofer?utm_source=bing&utm_medium=cpc&utm_campaign=UK%20-%20Sound%20%26%20PA%20-%20LT&utm_term=sub%20705-as%20ii&utm_content=20485-DA760BBD-BD72-4BAA-9E3C-D888AC9164C8S75728991109881&msclkid=05e6eea619f21619861db07b39ec1fa0

[BadBrainz]

You will need a sub with HPF outputs as the Art 312 does not have a built in HPF*

What is your budget? The obvious choice is to go for a an RCF sub, maybe the 705 AS-II**

* It used to be that all subs had the crossover built in and you fed the tops from the sub, these days the practice seems to be to include an HPF in the tops and subs just have the LPF and a link out. This is a little more flexible from a wiring POV but you need to be sure the HPF in the top and LPF in the sub match both WRT crossover frequency and slope. Having them both in the sub avoids the possible mismatch.

** https://www.bax-shop.co.uk/active-subwoofer/rcf-sub-705-as-ii-active-subwoofer?utm_source=bing&utm_medium=cpc&utm_campaign=UK%20-%20Sound%20%26%20PA%20-%20LT&utm_term=sub%20705-as%20ii&utm_content=20485-DA760BBD-BD72-4BAA-9E3C-D888AC9164C8S75728991109881&msclkid=05e6eea619f21619861db07b39ec1fa0

Thanks for your reply, every day is a school day! Unfortunately the RCF sub is out of my price range. I see that DB Technologies Sub615 I mentioned above is owned by rcf and that sub has a crossover. Does this mean its HPF output? And suitable for my speakers? Even though the alto has HPF output I've been put off after reading about their reliability. Are there any others you might suggest around my £500 budget?

[James Perrett]

I had a quick look at the Db Technologies unit and it appears to have a full crossover built-in as well as a polarity switch to help smooth the transition between sub and top (swapping the polarity between speakers is a well known trick to stop the two cancelling out at the crossover point where, in a simple crossover, the phase angle of one unit is shifted +90 degrees while the phase angle of the other unit is -90 degrees).

[BadBrainz]

I have been offered a good deal on an EV ELX200-18SP so now thinking about that one too.

[Sam Spoons]

It doesn't appear to have the HPF built in, just presets for the LPF to match the HPF in various models of EV ELX tops. So not going to work with your RCFs I'm afraid.

[BadBrainz]

Ok I'm obviously still struggling to understand. So the dB technology would be suitable with it crossover and polarity switch? But the EV won't be even though the crossover does 80/100/120/150hz? Getting very confused. As I said before I'm a complete novice.

[Sam Spoons]

A crossover splits the incoming signal into the mid/high frequencies which the top reproduces and the low frequencies which the sub reproduces. It does this by having a high pass filter (HPF) and a low pass filter (LPF) the HPF prevents the LF getting to the tops and the LPF prevents the highs getting to the sub.

The crossover in the DB has both the HPF and LPF built into the sub but the EV only has the LPF in the sub and needs to be used with tops that have a matching HPF built in which the matching EV tops do but your RCFs do not.

Does that help?

[BadBrainz]

Ok I think I'm understanding it. I will try and read about the dB Technologies some more.

I presume the HK audio pro 18 sub A would also suit my needs then?

Thank your for all your advice thus far. It's invaluable.

[Sam Spoons]

Yes, the HK would do the job.

If you have upped the budget to the HK price though you are only a few quid short of the RCF I linked above?

[BadBrainz]

The HK is £130 cheaper than the RCF. Im already stretching to that as it is. The DB Technologies 618 is cheaper again. I am at a loss which i should go for.

I am stuck between the HK & DB at the minute

Very annoying not being able to go out and test things...then again i would have to drive 2+ hours to the closes store with any of this kit.

[Sam Spoons]

Sorry yes, the link I found for the HK it was £689, Bax-Shop have it for £609 and the RCF for £739. HK stuff is pretty good, the first rig the PA hire company I worked for had was a HK Projector and it was pretty nice. That sub should be a decent match for your RCFs. The DB sub goes a fair bit louder but I have no experience of them so can only guess at reliability. On paper the DB is the best deal unless anybody has any horror stories about them?

[Drew Stephenson]

If you're not planning on using these semi-commercially then do you actually need the sub at all?

[BadBrainz]

Yes we have a lot of parties outdoors with friends sometimes 100 people and we like our bass I am not ruling out the odd event either.

[Drew Stephenson]

Fair enough!

[BadBrainz]

So i'm going to have a sleep on it but after reading everything i can find on forums/reviews im going to pull the trigger on a DB Technologies Sub618. A few people have mentioned it sounding great with the next speakers up from mine (RCF art712-a) so im going to hope it will do good things for mine.

My next question is a generator i have some money put aside for this (although i cant afford a diesel beast) i will be using mains power whenever possible but when i want to really crank it i'm going to have to go out away from the houses. I have been looking at Hyundai petrol inverter pure sine gennys. But once again the numbers hurt my head.

So can anybody tell me what sort of kva i need to power this setup?

plus my laptop/decks/few led lights (nothing high power other than the sound system)

[BadBrainz]

Sam i just saw your reply to my Genny question on the other thread i didnt get a notification so sorry about asking again.

Just one more question as im thinking ahead. If i was to add a 2nd DB Tech sub 618 would this Genny still be plenty?

https://hyundaipowerequipment.co.uk/hyu ... MxEALw_wcB

[Sam Spoons]

Yes, if you go back to my earlier post I list the gear I run off my Kippor 2 kW genny. Do take the time to read the whole post as there are potential issues with using petrol generators in local authority or commercial venues.

Also read the old post I linked to* as it details real world numbers and experiences.

* http://www.soundonsound.com/forum/viewtopic.php?f=26&t=36681#p335876

[James Perrett]

I own a few older dB Technologies speakers. Their power ratings are rather optimistic but they sound fine. One is currently out of action but the schematic is available on the internet and they use pretty standard parts so it appears to be fixable. I wouldn't have any worries about buying more of their gear.