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Title: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 14, 2021, 12:57:44 pm
I bought a bunch of old RCF subs at an auction loaded with L18-P200N drivers.
Boxes are decent enough, but the drivers needs replacement.
Some of them are ok, some of them are blown, there is a mixture of 4/8 ohms and so on.

The box is roughly 200L per driver, two round ports in each chamber with a diameter of 175mm, 300mm long.

Any ideas for a suitable replacement driver?
I have easy access to RCF/B&C, can get my hands on other brands, just a little more shipping costs.
Title: Re: RCF L18-P200N replacement
Post by: Ivan Beaver on April 14, 2021, 02:03:08 pm
I bought a bunch of old RCF subs at an auction loaded with L18-P200N drivers.
Boxes are decent enough, but the drivers needs replacement.
Some of them are ok, some of them are blown, there is a mixture of 4/8 ohms and so on.

The box is roughly 200L per driver, two round ports in each chamber with a diameter of 175mm, 300mm long.

Any ideas for a suitable replacement driver?
I have easy access to RCF/B&C, can get my hands on other brands, just a little more shipping costs.
Have you checked into simply reconing the drivers you have?
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 14, 2021, 02:52:00 pm
Have you checked into simply reconing the drivers you have?

Yes, talked to the distributor without luck, I got the impression these were discontinued from RCF.
I see some advertised online, some look after-market but a couple look like the real deal.
If anyone know of a good kit, I'll consider it. But not to keen on using time & money on reconing without knowing that the kit is good.
Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on April 14, 2021, 03:54:52 pm
Think I'd fire up WinISD or Hornresp and see what's what. The ports are a decent size, so you can probably put something pretty powerful in there without serious port losses. A B&C 18SW115 would be the first thing through my simulator.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 14, 2021, 04:21:49 pm
Think I'd fire up WinISD or Hornresp and see what's what. The ports are a decent size, so you can probably put something pretty powerful in there without serious port losses. A B&C 18SW115 would be the first thing through my simulator.

Chris

I did that with B&C and a couple of other manufacturers. 18TBX100 and TBW100 came out pretty good and about similar performance. 18TBW100 has a slight edge. 18SW115 only has a 1 dB advantage, so I'm thinking it might not be worth the extra $$$.
Then again, I could be wrong.
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 14, 2021, 04:40:10 pm
I did that with B&C and a couple of other manufacturers. 18TBX100 and TBW100 came out pretty good and about similar performance. 18TBW100 has a slight edge. 18SW115 only has a 1 dB advantage, so I'm thinking it might not be worth the extra $$$.
Then again, I could be wrong.

Ok, let me modify this slightly.
If i put in the 1500W available (intended amplifier) per driver, 18TBX100 is out of excursion. 18TBW100 is close to the limit, 18SW115 isn't even close.
So, given a bigger amplifier I should be able to extract more performance from 18TBW100 and a lot more form 18SW115?

Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on April 15, 2021, 02:25:45 am
Ok, let me modify this slightly.
If i put in the 1500W available (intended amplifier) per driver, 18TBX100 is out of excursion. 18TBW100 is close to the limit, 18SW115 isn't even close.
So, given a bigger amplifier I should be able to extract more performance from 18TBW100 and a lot more form 18SW115?

Correct. The 18SW115 is rated for more power, and IIRC also has more excursion. ie, greater output potential. It all amounts to getting more sound out of the same amount of cabinets, but as you've noted, more power input will also be required.
IMO, increasing output density (dB/L) is a Big Deal. Most of my cabinets are optimised in that direction, and I use high-end drivers and plenty of power to get the job done. It means I can pull off some impressive stuff, like a stadium setup with 2x 15" subs and 1x 2x10"+HF per side hitting 85dBC-slow (103dB peak) at 85m.

I don't know how important weight is to you, but going for neodymium drivers will save you a few kg.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 15, 2021, 02:40:03 am
Correct. The 18SW115 is rated for more power, and IIRC also has more excursion. ie, greater output potential. It all amounts to getting more sound out of the same amount of cabinets, but as you've noted, more power input will also be required.
IMO, increasing output density (dB/L) is a Big Deal. Most of my cabinets are optimised in that direction, and I use high-end drivers and plenty of power to get the job done. It means I can pull off some impressive stuff, like a stadium setup with 2x 15" subs and 1x 2x10"+HF per side hitting 85dBC-slow (103dB peak) at 85m.

I don't know how important weight is to you, but going for neodymium drivers will save you a few kg.

Chris

Weigh saving is an issue, not so much on this project. Lost 12kgs per box switching to neo in my KF750.
I'm going to check a few neo drivers and look at what's possible in terms of SPL/$$$ and amp/$$$.

Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 15, 2021, 04:35:29 am
I have 18TLW3000 in some subs already, simulates pretty good in this box. I'd say it matches the 18SW115 pretty good (in this box).
Going to pull out a pair and test it, I didn't think it would fit so I didn't consider it initially.
Having more drivers of the same kind = extra backup.
Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on April 16, 2021, 03:04:28 am
Sounds like a plan. Keep us updated please.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Steve Litcher on April 22, 2021, 04:41:46 pm
This thread is from a few years ago, but I had good luck using 18Sound drivers as replacements in my SB180R cabinets (which were shipped with L18-P200N drivers).

https://forums.prosoundweb.com/index.php?topic=159892.0

I eventually sold the SB180Rs but the 18Sound substitutes worked and sounded great.
Title: Re: RCF L18-P200N replacement
Post by: Jim McKeveny on April 23, 2021, 07:52:39 am
This is a tough one, actually. (I'm assuming RCF no longer makes their easy to use use drop-in recone kits for the 200). Anything "modern" you install in those boxes will have more X-max and more thermal (power) handling, both of which could rapidly expose port limitations.
Title: Re: RCF L18-P200N replacement
Post by: Uwe Riemer2 on April 24, 2021, 02:27:14 am
This is a tough one, actually. (I'm assuming RCF no longer makes their easy to use use drop-in recone kits for the 200). Anything "modern" you install in those boxes will have more X-max and more thermal (power) handling, both of which could rapidly expose port limitations.
According to the web Thomann still sells recone kits for the 18P200 Typ 2 and some recone companies in Germany list prices for KN and N versions.
AFAIR KN/N sounds more familiar to me than Typ 2, but this could be easily solved by making some old school phone ( not cell ) calls appropriate for the driver.

On the other side two 175mm round ports seems not bad for 1500W and the new mid class of 12mm X max drivers.
Tuning could be a little on the highish side, so the problem could turn into: How to make the 175mm round port longer.

Lets see if the OP wants to tell us about the TLW drop in.

And to close my little contribution: I would never even dream of putting the SW115 in 200l

Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on April 24, 2021, 03:48:20 am
According to the web Thomann still sells recone kits for the 18P200 Typ 2 and some recone companies in Germany list prices for KN and N versions.
AFAIR KN/N sounds more familiar to me than Typ 2, but this could be easily solved by making some old school phone ( not cell ) calls appropriate for the driver.

On the other side two 175mm round ports seems not bad for 1500W and the new mid class of 12mm X max drivers.
Tuning could be a little on the highish side, so the problem could turn into: How to make the 175mm round port longer.

Lets see if the OP wants to tell us about the TLW drop in.

And to close my little contribution: I would never even dream of putting the SW115 in 200l



Landed a two week installation gig so things are on hold in the diy-department at the moment, but I also noticed that Thomann sells that recone kit.
I'm considering ordering one, drop a fresh recone in one chamber and a TLW in the other for some comparison tests.

Title: Re: RCF L18-P200N replacement
Post by: Mark Wilkinson on April 25, 2021, 03:29:16 pm


And to close my little contribution: I would never even dream of putting the SW115 in 200l

Hi Uwe, why not?
Title: Re: RCF L18-P200N replacement
Post by: Uwe Riemer2 on April 27, 2021, 08:07:39 am
Hi Uwe, why not?
You always ask the big questions  :)

So what are the trade offs, if we put the driver in 200l compared to the 150l suggested design from B&C:
We gain extended range to the low end, which comes at the price of higher Group Delay ( and no, we cannot trade Group delay for simple delay here, we need the sound to happen now )
We lose efficiency, we lose maximum output above tuning.


But in the end you need to try out for yourself and see what you like better, or because this is a Live Sound Forum find out what is the more useful tool in SR.


Title: Re: RCF L18-P200N replacement
Post by: Mark Wilkinson on April 27, 2021, 12:51:10 pm
You always ask the big questions  :)

So what are the trade offs, if we put the driver in 200l compared to the 150l suggested design from B&C:
We gain extended range to the low end, which comes at the price of higher Group Delay ( and no, we cannot trade Group delay for simple delay here, we need the sound to happen now )
We lose efficiency, we lose maximum output above tuning.


But in the end you need to try out for yourself and see what you like better, or because this is a Live Sound Forum find out what is the more useful tool in SR.

I looked at group delay for the B&C at 150L vs 200L and see what you mean.   Nice catch, something I'll pay more attention to on vented boxes from now on.

Re the more useful tool for live sound..... i stick to  front loaded horn subs for live, like Labhorns or Orbitshifters, so group delay is as low as it realistically gets, i think.

My bass-reflex are for home use and playback, so i can remove group delay via a boatload of FIR....and is why I never bothered to look at it before for vented subs.
That said, I'm a firm believer in the rule that 'the best designs require the least processing'.....so thanks for the pointer  :)
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on May 10, 2021, 03:13:58 pm
Update on this project.
RCF confirmed that recone kits for 18P200N-II doesn't fit on the L18P200N frames. So reconing is off.
18TLW3000 doesn't fit inside the cabinet, there is some bracing in the way. It's off or I need to consider some woodworking.

B&C 18TBX100 fits and looks like a decent replacement in WinISD.
In terms of power, it looks like I can put in around 1KW per driver before I run into Xmax-limitations.
1.2KW if I use Xvar.

In terms of amplifier power, what would you suggest as a good target number per driver?
I've been looking at wiring 8 ohm drivers in pair and feeding them 2500W/4 ohm. I think this is "enough" for these boxes.
Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on May 10, 2021, 04:28:57 pm
A Powersoft T602 conveniently puts out 2500w/ch into 4ohm  ;)

IIRC, Xvar is what B&C would like you to use. I think that's based on harmonic distortion levels, rather than the simple motor geometry that Xmax is often based on.

I usually like to test the useful excursion of drivers myself, though. I have some Beyma 15P1200Nd drivers which are rated for 9.5mm of Xmax, but you can push them to 15mm without them complaining much - their mechanical overload is very graceful, but that's not in the datasheet.


Sizing the amplifier will depend on the program material etc - you need to keep in mind that the excursion curves in WinISD are what happens when you put in 90V RMS (or whatever level you're running at) into the drivers at one frequency. That's very rare in music, but not impossible.
I'd usually like 2x the driver's AES power rating for the amplifier, but that's not always cheap or convenient.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on May 10, 2021, 04:42:36 pm
A Powersoft T602 conveniently puts out 2500w/ch into 4ohm  ;)


Chris
Its the one Ive been looking at. Not suprised you guessed it  ;)
Agree on the 2x RMS figure, but were talking K20 or going with one amp channel per driver in 4 ohm.
Starts to get expensive and a lot of cabling/logistics.
Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on May 11, 2021, 03:02:30 pm
Agreed.
I went from Crown MA12000i to Powersoft T602. Haven't missed that last 3dB (less, at 2ohm), but the networking and DSP have been great to have.

FWIW, having abused a T602 (bridged into a 4ohm sub, pushed 6dB into clip while playing dubstep), I can say those amps hold up well, and the clipping isn't obvious. A reduction in "impact", but that could also have been the drivers being driven past Xmax.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on May 11, 2021, 04:36:56 pm
Agreed.
I went from Crown MA12000i to Powersoft T602. Haven't missed that last 3dB (less, at 2ohm), but the networking and DSP have been great to have.

FWIW, having abused a T602 (bridged into a 4ohm sub, pushed 6dB into clip while playing dubstep), I can say those amps hold up well, and the clipping isn't obvious. A reduction in "impact", but that could also have been the drivers being driven past Xmax.

Chris

My main amp is a X8 Dante so T-series fits right into the SW platform.
Run a K20DSP for some subs I built a few years ago, sounds absolutely fantastic, but the same subs on X8 isn't that far behind. You notice a difference, especially if you go 2 ohm crazy. I bet the new X4L is a killer.
T and X is pretty similar IME, X has a bigger PSU and have more horsepower, but T is on par in terms of SQ.
Title: Re: RCF L18-P200N replacement
Post by: Chris Grimshaw on May 12, 2021, 05:16:49 pm
T and X is pretty similar IME, X has a bigger PSU and have more horsepower, but T is on par in terms of SQ.

That's cool to hear. I don't really have any use for the X series amps, apart from pushing my subs further into power compression, but it's nice to know the T-series amps sound as good.

I have heard the X8 wouldn't like 2ohm subs on every channel, but I rather think that's to be expected - it's a very difficult use case. The X4L looks like a real beast, though.

Chris
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on May 12, 2021, 05:44:10 pm
That's cool to hear. I don't really have any use for the X series amps, apart from pushing my subs further into power compression, but it's nice to know the T-series amps sound as good.

I have heard the X8 wouldn't like 2ohm subs on every channel, but I rather think that's to be expected - it's a very difficult use case. The X4L looks like a real beast, though.

Chris

I've used 4x EAW SB2001 on a X4 in anger, powered by 400V/3phase/16A. Subs wired in 2 ohm.
That's insane, 20800W on 8x21" drivers with some serious SPL from what's basically the size of a pizza box....
X-series is awesome, T-series is damn good as well. Not just "inspired by" :)
Title: Re: RCF L18-P200N replacement
Post by: Helge A Bentsen on June 14, 2021, 01:57:15 pm
This is moving (slowly) forward.
Got new grilles made, they look so good unpainted that I'm thinking about skipping the paint job on them.
Also have a pair of  drivers on their way for some testing.