Compact budget PA set-up to put bass through (without back-line).

[Greg Edwards69]

Thanks Bill, I think I just about understand the science!

 

The test room was a large rehearsal room.  Let's say around 18m x 10m. Band set up at one end in usual gig configuration. Top speakers on either side of the "stage" area , probably around 1 meter from each wall - so about 8m apart. Sub on the floor next to 1 speaker - around 1m to 1.5m from the wall. With some test music playing through the system, and walking from one side of the room to the other at the opposite end of the room you could definitely hear the difference in low-end content.

 

It's also worth noting that the DXR12 tops have a lowest hpf setting of 100hz, so the sub is set to match. Personally, I feel it would be better if they could be set to 80hz.

 

If I understand you correctly, the adjacent wall to the sub increased the boundary effect, and therefore combined with the listening position increase the, shall we call it the "locality" effect - the ability to locate where the sound is coming from.

 

Therefore, in some typical pub venues where the tops and sub are in open space with no directly adjacent walls, there should be less of the "locality" effect?

 

The next two gigs should be ideal for experimenting with this. The first is a large long room with a wide and shallow stage riser. The sub can easily go directly in the middle.  The next is a wide pub with about 5m+ of clear space either side of the stage, but the stage protrudes in the middle into the "dance floor" area, so the sub has to go on one side of the protrusion so people don't fall over it. With both gigs there'll be opportunity to play some test music though the system when we set up.

[Bill Fitzmaurice]

Boundaries will enhance the lows when the sub is close enough..and 1 meter isn't... and will cause low frequency response notches when the sub and/or the listener is in the .75 to 2.15 meter range from the boundary. They have no effect on subs being directionally locatable, as they don't affect the harmonics. One way to both lessen the distance to the wall and attenuate harmonics is to aim the sub at the wall. Try setting the sub low pass to 80Hz. It doesn't necessarily have to be set at the same frequency as the mains high pass.

[Downunderwonder]

One way to find where best to put your sub is a very simple experiment.

 

Put it where you want the biggest bass ie the middle of the dancefloor. Play a bass heavy track and go around the room to find the best booming position of the available wall spots to put the sub for the show.

 

Put the sub there and it will thump back where you want it.

[Al Krow]

Well having started this thread some 30 months ago, appears I'm nearing the final couple of laps! Sold the last of my amps and cabs today (a rather nice Fearless F112) - end of an era for me! 

 

But a good opportunity to use the cash to upgrade the PA with some better speakers (RCF 912A --> 932A?), a decent digital desk, and maybe a budget subwoofer. Ooops, I think I may have just spent the proceeds a couple of time over 😅 

[Phil Starr]

I'm not sure I could be so disciplined as to sell my last bass cab, even though it is so rarely used.  I do love the Fearless cabs too. My probably final cab is a LFSys Monza and it does seem a bit grand for a 'just in case' gig.

 

I think the RCF 732 is a great choice btw. Those big horn drivers do make the vocals sound good and my 745's are overkill for 90% of our gigs.

 

GAS never goes away though, I keep eying up a pair of these https://www.thomann.co.uk/rcf_nxl_24_a_mk2.htm

[mrtcat]

On 30/09/2024 at 16:07, Al Krow said:

Sold the last of my amps and cabs today (a rather nice Fearless F112) - end of an era for me!

They'll have to prize my F112 from my cold dead hands when my time is up.

[Chienmortbb]

6 hours ago, Phil Starr said:

GAS never goes away though, I keep eying up a pair of these https://www.thomann.co.uk/rcf_nxl_24_a_mk2.htm

True, those RCFs look nice but at close on 25Kg, they would never get out of the garage!

[Phil Starr]

16 minutes ago, Chienmortbb said:

True, those RCFs look nice but at close on 25Kg, they would never get out of the garage!

I'm teasing Al a bit but I've heard these and they sound wonderful. They 'only' weigh 5kg more than my ART745's and at over a metre high I wouldn't need to lift them over head height They'd pack into the car more easily and be more stable on stands. the bigger issue is that I'd need to take a sub for more gigs.

[Woodinblack]

Honestly if you were going to use those and a sub, you could just get some Evox 12s, which would give you something similar as well as a 15" bass. You certainly wouldn't need to lift them head hight, which is handy as they are another 10kg on those, but at least they come with wheels!

 

[Jack]

On 30/09/2024 at 16:07, Al Krow said:

Well having started this thread some 30 months ago, appears I'm nearing the final couple of laps! Sold the last of my amps and cabs today (a rather nice Fearless F112) - end of an era for me! 

 

But a good opportunity to use the cash to upgrade the PA with some better speakers (RCF 912A --> 932A?), a decent digital desk, and maybe a budget subwoofer. Ooops, I think I may have just spent the proceeds a couple of time over 😅 

The indie band that I was in until recently went from 712 (the drummer's) to 732 (which the guitarist bought for another project) and I was skeptical that it would make much difference but actually it was quite profound. (No, this test wasn't double blind, yes, my expectations and room will affect.) You might be surprised at the upgrade. I will say though that nothing has changed my gigging life more than getting a digital mixer 8 years ago. That's where to go first IME.

Edited October 3 by Jack

[Al Krow]

Agreed that the 732As are a step up, certainly for vox (interestingly not so much for bass). Our singer has those for her solo work, plus brings them to half the band gigs. We use my 912As for the remaining band gigs, to share the PA transport load between us.

 

I was actually thinking of getting the RCF 932As rather than the 732As by way of upgrade for mine.

 

I agree a digital desk would be a really good addition too, and as you say @Jack should probably be the priority in order of importance.

[Jack]

1 minute ago, Al Krow said:

Agreed that the 732As are a step up, certainly for vox (interestingly not so much for bass). Our singer has those for her solo work, plus brings them to half the band gigs. We use my 912As for the remaining band gigs, to share the PA transport load between us.

 

I was actually thinking of getting the RCF 932As rather than the 732As by way of upgrade for mine.

 

I agree a digital desk would be a really good addition too, and as you say @Jack should probably be the priority in order of importance.

Yes sorry I saw that, I was commenting on the benefits of going from X12 to X32. Either way, shiny new gear is always fun.

[Phil Starr]

Across the RCF ART range the first number indicates better bass drivers and bigger magnets as well as slightly better cabs. The bigger magnets give better damping of the cone movement and a tighter bass sound as well as slightly improved excursion and sensitivity.

 

The nice thing is that re-sale values for quality used active speakers are really good at the moment in the UK so you can usually get most of your money back when you upgrade.

[Al Krow]

25 minutes ago, Phil Starr said:

Across the RCF ART range the first number indicates better bass drivers and bigger magnets as well as slightly better cabs. The bigger magnets give better damping of the cone movement and a tighter bass sound as well as slightly improved excursion and sensitivity.

 

The nice thing is that re-sale values for quality used active speakers are really good at the moment in the UK so you can usually get most of your money back when you upgrade.

 

Oh that's good to hear, Phil. Any particular forums you are seeing active bass speakers being listed and sold?

[Phil Starr]

1 hour ago, Al Krow said:

 

Oh that's good to hear, Phil. Any particular forums you are seeing active bass speakers being listed and sold?

There's loads of them on Facebook Marketplace, I picked up my 745's from there and also a 905 sub

 

eBay has changed it's terms so you can sell for free too. I think that will shake up the second hand market.

Edited October 3 by Phil Starr

[Jack]

2 hours ago, Phil Starr said:

Across the RCF ART range the first number indicates better bass drivers and bigger magnets as well as slightly better cabs. The bigger magnets give better damping of the cone movement and a tighter bass sound as well as slightly improved excursion and sensitivity.

 

The nice thing is that re-sale values for quality used active speakers are really good at the moment in the UK so you can usually get most of your money back when you upgrade.

Second number? 

 

First one is the series. 

Edited October 3 by Jack

[Al Krow]

46 minutes ago, Jack said:

Second number? 

 

First one is the series. 

 

My understanding is:

First - series (but maybe equates to the features Phil was highlighting?): 3(basic), 7, 9(premium)

Second - ??

Third - speaker cone size 0 = 10", 2 = 12", 5 = 15"

 

Actually I'm not 100% sure what the second number specifies? Some sites (eg Bax) mention Tweeter size, others imply 3 = 3" voice coil. 

Edited October 3 by Al Krow

[jrixn1]

1 hour ago, Al Krow said:

Actually I'm not 100% sure what the second number specifies? Some sites (eg Bax) mention Tweeter size, others imply 3 = 3" voice coil. 

 

It's the voice coil of the compression driver. Even RCF's own marketing isn't always that clear ('The 1.4" compression driver offers unique vocal clarity and sound projection'), but they do list it properly in the actual specs ('Compression Driver: 1 x 1.0", 1.4" v.c').  The exception is the smaller speakers like 708, which doesn't have a 0" voice coil 🙂

[Al Krow]

1 hour ago, jrixn1 said:

 

It's the voice coil of the compression driver. Even RCF's own marketing isn't always that clear ('The 1.4" compression driver offers unique vocal clarity and sound projection'), but they do list it properly in the actual specs ('Compression Driver: 1 x 1.0", 1.4" v.c').  The exception is the smaller speakers like 708, which doesn't have a 0" voice coil 🙂

 

I guess the follow on question is how does the set up vary between say the 912A and 932A (or 712A and 732A) eg do they have same tweeter/horn set up? And how/why is the voice coil dimension so important, that it becomes a key RCF reference number?

[Phil Starr]

First number is the series number and is basically about the bass driver and the cab. They used to have a 'basic' range the 3-series a couple of years ago. The 7 series at each size level had better bass drivers and slightly more rigid cabs. Then they introduced the 9 series which uses better bass drivers again.

 

Second number signifies the size of the compression unit, the speaker that drives the horn. The 1 in the ART 712 for example means that the horn has a 1" throat though confusingly the horn driver might be 1.5" or 1.75 depending upon the size of the bass driver it is matched to. They also do a 3" and 4" horn driver. Having a bigger voice coil increases the heat dissipation of the driver and this in turn increases power handling. Crucially though it allows a lower crossover frequency so more of the voice goes through the horn which improves dispersion and the accuracy of the vocal reproduction in particular.

 

The final Number as everyone has said is the size of the bass driver.

 

I only know all this because I auditioned a few speakers when I first upgraded my old passive Yamaha PA and at each price point I found the best speaker in terms of accurate reproduction was the RCF. At teh time the range was really confusing with a 4 series the HD range and other odd speakers so I wanted to research exactly what I was buying. RCF started out just making drive units (they made the drive units for the original Mackie SRM450's for example) and if you go across to Blue Aran you can see the specs of the bare drive units. The 4" horn drive costs £320 (more than the bass driver) and handles 140W for example which kind of explains why the cabs cost what they do. There are also some helpful You Tube video's by one of the US dealers where they pull the latest RCF speakers apart so you can see what RCF put inside the boxes.

 

 

 

 

[mrtcat]

17 hours ago, Woodinblack said:

Honestly if you were going to use those and a sub, you could just get some Evox 12s, which would give you something similar as well as a 15" bass.

 

The NXL 24 is a world away from the evox range. 

[Phil Starr]

8 hours ago, Al Krow said:

 

I guess the follow on question is how does the set up vary between say the 912A and 932A (or 712A and 732A) eg do they have same tweeter/horn set up? And how/why is the voice coil dimension so important, that it becomes a key RCF reference number?

As far as i can tell RCF only make one 3" and one 4" driver https://www.bluearan.co.uk/index.php?id=RCFND950_2_0 so I'm guessing that they use the same 3 or 4 in all their ART cabs and I think in some/most of the NX range.

 

To understand why it's important you need to know a bit about our biology. The most important sounds to us are in the midrange, say 500-5,000 hz our ears are incredibly sensitive in that region and most of the information we need to survive is there including most human speech. Most animals alarm calls are there too. The bass is turned down in our hearing otherwise we'd walk around listening to ou bones creaking and other bodily noises and actually only really loud bass notes would signify danger in more primitive times. The bass is turned up for the loudest noises.

 

So if we hear the mids better and it's 90% of what we process as music then your PA has to be good at mids. Unfortunately due to the physics of speakers big cones don't do mids well. they are heavy old things that don't move back and forth thousands of times a second very easily. Also the radiation pattern is related to the wavelength of the sound and big speakers beam high frequencies so you need a small speaker for high frequencies and a big speaker for bass. This means a crossover and at least two speakers, three might be better but that is extra cost, weight and a technical problem; crossovers introduce distortion!

 

For practical reasons most 2-way PA speakers crossover between 2-3,000Hz just about where our hearing is most sensitive. That's partly because it evenly splits the sound but also because of power handling. Bass contains more energy or watts and more watts will burn out small voice coils. It's difficult to make the voice coil bigger than the cone or dome of a speaker. A typical 1x12 PA speaker will have a 1.5-1.75" diameter voice coil handling only around 35W of power. The 4" driver in the most expensive RCF speakers allows 140W of power handling and the crossover point to be reduced below 1,000Hz cleaning up a whole octave or more of the midrange frequencies.

 

All speaker design is a compromise and not just of expense. At a given price point you can concentrate on a better bass driver or a better horn driver. The 912 favours bass and the 732 the midrange or vocals. It helps to know what you are paying for and designing a big tweeter is difficult if you are not to lose some of the real high end. That 4" horn driver is extraordinarily expensive big and heavy for a reason.

[Al Krow]

3 hours ago, Phil Starr said:

The 912 favours bass and the 732 the midrange or vocals. It helps to know what you are paying for and designing a big tweeter is difficult if you are not to lose some of the real high end. 

 

Thanks for the earlier two posts Phil. Quoting part of the first above...

 

Having regular access to both 912A and 732A, I agree that comparing the two, the 912A is a (little) better on bass and the 732A noticeably better for mids/vox.

 

I'm therefore hoping that the RCF 932A should deliver the best of both worlds?

[Phil Starr]

19 hours ago, Al Krow said:

the 912A is a (little) better on bass and the 732A noticeably better for mids/vox.

 

I'm therefore hoping that the RCF 932A should deliver the best of both worlds?

Yes, I can't be totally certain that RCF will have made no modifications to either driver but essentially you are getting the better bass driver with the better horn driver. The rest of the system amp, crossover and the cab itself will all be different but one reason for the current success of RCF designs is the care with which they marry their components. I'd expect it to deliver just what you want.

 

It's probably fair to compare this with how they design modern cars. A particular manufacturer will try and use the same engine across a whole range of models suitably modifying things to optiise them for each body shape. Somwhere in the range you'll find a model with your favoured engine with the format you prefer at the trim level you want.

 

Incidentally you could also consider the RCF NX 932, essentially the same speaker but in a wooden box. I have never heard the two speakers but generally speaking when I've done listening tests with plastic PA cabs and elecctric bass there is a noticeable difference between wooden and plastic cabs with the more rigid wooden cabs sounding a lot better defined due to their increased rigidity. I'd expect this to be true for the NX series too. £819 plays £1179 though and the wooden cab is around 1.5kg heavier.

[Al Krow]

4 hours ago, Phil Starr said:

Incidentally you could also consider the RCF NX 932, essentially the same speaker but in a wooden box. I have never heard the two speakers but generally speaking when I've done listening tests with plastic PA cabs and elecctric bass there is a noticeable difference between wooden and plastic cabs with the more rigid wooden cabs sounding a lot better defined due to their increased rigidity. I'd expect this to be true for the NX series too. £819 plays £1179 though and the wooden cab is around 1.5kg heavier.

 

The best prices I can find online currently are:

932A - £790

NX 932A - £1,099

(Then need to add another £50 for the RCF padded covers, which are worth getting).

 

So a pair of NX's are going to add another £600, which is decently chunky and I suspect that the tough plastic casing is going to cope with the usual knocks that all bass gear gets in live use and, paradoxically, where a more rigid structure is likely to cope less well?

Edited October 5 by Al Krow