Speaker columns

[zitherman]

Given that the latest pa systems are line array,how similar are they to the 4x12 speaker columns of the 70s,80s.with this in mind could a 4x 12 column be updated to give good performance whilst keeping the look.Internal mods would be ok,cheers

[Bill Fitzmaurice]

The main difference it that the old style 12" loaded columns usually didn't have tweeters, so they weren't much good above 3kHz. Columns equipped with tweeters would have been far superior to the woofer plus HF horn cabs that replaced them, but AFAIK no one ever made one. 

[zitherman]

Thamks.Bill,i.was.thinking about modding the top.aperture to take a proper.hf horn,leaving the.next.2 as mids and making the.bottom one bass albeit with some internal.mods.cheers

[Bill Fitzmaurice]

Nope, because then you lose the advantage of sensitivity and vertical pattern control of the column. The right way would be to use at least four tweeters arrayed vertically to one side of the woofers, in this fashion.

 

[Phil Starr]

4 hours ago, zitherman said:

Thamks.Bill,i.was.thinking about modding the top.aperture to take a proper.hf horn,leaving the.next.2 as mids and making the.bottom one bass albeit with some internal.mods.cheers

I'm not convinced as to why you would do this either. These were built in the days when materials science hadn't caught up with PA needs and gear was very expensive. PA was still largely about getting as much sound as possible out of speakers that wouldn't handle huge amounts of power so multiple cheap drivers was the rule of the day. Plus of course th excellent dispersion patterns of vertical arrays. Using two 12's for mids is a bit odd as they already have issues in the mid-range.

 

The truth is that these things were never great and it took all we had in those days to coax a decent sound out of them. Thre were a few 4x12 collumns with horns ( I vaguely remember WEM made some)  but they were uber-expensive at the time and beyond the reach of most bands. This was Pink Floyd's touring rig in 1969

 

[zitherman]

Thanks for your reply phil.Its for a small themed band.Just really wondering if its possible to get acceptable sound quality and reasonable volume from them in todays world.I realise calcs would be desirable if upgrading to modern drivers and also possibly internal mods.cheers

[Bill Fitzmaurice]

16 minutes ago, Phil Starr said:

 PA was still largely about getting as much sound as possible out of speakers that wouldn't handle huge amounts of power so multiple cheap drivers was the rule of the day.

The truth of the matter is that the benefits of column speakers were well known going back to the 1940s, the main one being vertical pattern control. They worked far better than point sources in reverberant spaces, like clubs and other large gathering places . Perhaps the most noteworthy installation of them was in St. Paul's of London circa 1950. They worked well there for some fifty years before being upgraded with modern line sources. The demise of the column speaker came for two reasons. Foremost was the lack of high frequency drivers, so they sounded dull compared to point sources that had high frequency drivers, like the Altec A7, which spawned hundreds of similar designs. But there was also the fact that most users had no idea why they had good vertical pattern control, or for that matter what vertical pattern control was, let alone what comb filtering was and why placing PA cabs side by side was the worst possible configuration. It didn't help when trapezoid array cabs were introduced. They were supposed to make horizontal dispersion better, instead they made it worse. No matter, they were what buyers wanted, and manufacturers were more than happy to supply them.  

[Downunderwonder]

At least mini skirts are back in fashion.

[zitherman]

Thanks for your replies.I was hoping bill and phil would comment as they have far superior knowledge than me.Looks like converting existing columns is not feasible so ill look into constructing my own ,maybe along the lines of bills picture.More thought and study required.cheers.

[SimonK]

...if you are going to build a speaker enclosure (and you don't already have a degree in acoustics) best to binge watch Barefaced Audio's youtube channel - Alex is very good at explaining everything, and also answers emails!

[zitherman]

Cheers,ill have a look

[Bill Fitzmaurice]

You may be able to use the existing box with a new baffle, which should leave room for a line of eights or tens plus a line of tweeters.

[Phil Starr]

19 hours ago, zitherman said:

Thanks for your reply phil.Its for a small themed band.Just really wondering if its possible to get acceptable sound quality and reasonable volume from them in todays world.I realise calcs would be desirable if upgrading to modern drivers and also possibly internal mods.cheers

 

OK that sounds interesting. I quite like a challenge so tell us about the band, what's the theme? What is the line up and where will you be playing? Which instruments willyou be putting through this PA? Do you have a budget in mind?

 

Technically a 'line' isn't a bad idea, hence all the 'me-too' sub and a stick systems or the touring bands true line arrays. There's absolutely no reason why something like Bill's design above couldn't work extremely well and there are other solutions which would give you the same visuals but with modern performance levels. You can hide a lot behind a speaker grille and I'm picturing something like the old WEM 4x10's, I believe you can still get the old style grille cloth and the vinyl speaker covering if you wanted to make it really authentic. A quick calculation shows it wouldn't be difficult to make a 4x8 with a response 3db down at 50Hz and 900W handling and 127dB output. That's AES ratings, Yamaha, RCF and most of the rest add an extra 6db so its 3,600W and 133db if you want to compare it with commercial cabs claims

 

How would you be powering this speaker? Your biggest problem in the design will be the crossover.

[Mottlefeeder]

7 hours ago, zitherman said:

...Looks like converting existing columns is not feasible so ill look into constructing my own ,maybe along the lines of bill's picture.

The picture is of one of Bill's designs - you could do a lot worse than buy his plans and build one of them.

https://billfitzmaurice.info/SLA.html

I have no connection to Bill other than having built several of his designs.

David

[zitherman]

This.may.sound a little.bizarre but the columns  were to be the base to make them look like old american.gas pumps .we have double bass,banjo and a suitcase bass drum.we are a slightly off the wall duo but still want a clean powerful sound in the pubs we are intending to play.

[Chienmortbb]

On 19/02/2024 at 22:26, Phil Starr said:

Using two 12's for mids is a bit odd as they already have issues in the mid-range.

Those 4x12/4c10 columns were built for two reasons. In the UK,  there were three main guitar speakers makers, Goodmans,  Fane and Celestion. These speakers were usually 25-30 watts so to match the amps of the day, 4 were used in each column. Most amps were 30/40 or 100 watts. WEM, made 49 and 100 watts solid state amps. Using two 8 ohm columns meant that the drivers did not get to the point of come breakup, so beloved of guitarists. 
 

Were they as good as a good modern PA speaker?  No but they were probably as good as the cheaper plastic speakers available  today. 

[zitherman]

I recall having a pair of bins made by custom sound.they had 100w 15 inch fanes and were bombproof.near the end of their life some 30 years later they lived outside on a trailer covered by a tarp and still kept going.eventually the chipboard cabinet fell apart

[Phil Starr]

Oh goody, this is turning into a reminiscence 😂😁

 

I was going to say in response to @Bill Fitzmaurice that we really strugled over here in the late 60's/early 70's as the better US made speakers like EV and JBL were fearsomely expensive over here. Of the three speaker brands mentioned Fane were the budget brand at the time but 12" speakers at the affordable end were usually rated at around 25-30W as  John has pointed out, and WEM's 4x10 columns were rated at under 100W. Top end response generally at the time was provided by having a second smaller cone added to the front of the voice coil former called a whizzer cone. Voice coils were short to keep the efficiency up as high as possible and the speakers literally bunt out if pushed hard as the coil was wrapped around a paper former and stuck together with a protein based glue. Replacing speakers was a regular task. There wasn't a lot of choice of ready made PA speakers around and a lot of small custom builders. To get the most out of an expensive speaker I built a lot of very big horn cabinets and I spent weeks designing a hybrid cab which came out within an inch or two in every dimension of the Altec A7. At the time they sounded really good but I do wonder how they woulkd compare now. I doubt that those 4x10 columns would compete well with todays cabs, even cheap ones.

 

However there is nothing wrong with the theoretical advantages of a column speaker in terms of dispersion and it offers a chance to move the crossover point(s) away from the critical midrange where our hearing is most sensitive.

 

 

[JPJ]

Ooh I like the look of that SLA Pro PA top 😍

Edited February 21 by JPJ

[JPJ]

15 hours ago, Mottlefeeder said:

The picture is of one of Bill's designs - you could do a lot worse than buy his plans and build one of them.

https://billfitzmaurice.info/SLA.html

I have no connection to Bill other than having built several of his designs.

David

What I meant to say was Ooh I like the look of that SLA Pro PA top from Bill 😍

Edited February 21 by JPJ

[zitherman]

Having had a look at bills comprehensive website which i found very interesting ,is it feasible to scale up his sla pro design to 4x10 plus tweeters and keep the advantages of the original design.the cabinetry isnt a problem for me but the correct dimensions and hence volume would require a new skill set for me.cheers

[JPJ]

2 hours ago, zitherman said:

Having had a look at bills comprehensive website which i found very interesting ,is it feasible to scale up his sla pro design to 4x10 plus tweeters and keep the advantages of the original design.the cabinetry isnt a problem for me but the correct dimensions and hence volume would require a new skill set for me.cheers

I was thinking 8” rather than 10’s myself, given the performance of modern drivers. 

[Bill Fitzmaurice]

TLAH Pro uses eights.  I didn't create a ten inch loaded version as when you get that large it's more practical to stack smaller single or dual woofer cabs. All of the DR, Jack and OmniTop designs have that ability, and being horn loaded have much higher sensitivity.