Question concerning "end fire subs"

[Dick Rees]

Re: Question concerning "end fire subs"

I think a lot of the decision on what setup to use should be based on what it is that one wants the subs to do. If the main function of the subs is to give a kick the gut-wrenching quality that we crave, then a centre clustre/array is the thing. If the main function is to provide downward extension for several instruments, and the performance around crossover frequency is important, then it often makes sense to go with tops and subs together. It all depends on what frequency is most important, and wether considerations about power alley and stage volume are important or not.

Lykke til!!

Per......

In this case it's both situations in one 10-hour day. Some of the styles require the kick-in-the-gut, some require the downward extension and harmonic support. I'd like to try the 3:1 cardioid, but that would require some ambitious re-wiring in my amp rack as the DX38 is 2 in/4 out. I'd have to use some splitters and another cross-over......but I do have another (analog) crossover in the rack as a spare.

We'll see.

 

[Per Søvik]

Re: Question concerning "end fire subs"

Per......

In this case it's both situations in one 10-hour day. Some of the styles require the kick-in-the-gut, some require the downward extension and harmonic support. I'd like to try the 3:1 cardioid, but that would require some ambitious re-wiring in my amp rack as the DX38 is 2 in/4 out. I'd have to use some splitters and another cross-over......but I do have another (analog) crossover in the rack as a spare.

We'll see.

I guess the DX38 isn't really suitable for subs, having only a short delay for alignment between horn and midrange in a biamped box. I doesen't really matter what configuration you go for, any configuration that is not a straight cluster requires at least one delay around 4mS. One problem with 3:1 is of course that you need individual amps for all subs, if you have the subs on a big two channel amp, then it is out of the question. I have four channels, but my problem is that I can't set individual right and left delays on the DRPA+ (didn't try too hard), so I ended up just going thru a delay after the x-over. Only got four subs of my own, would really like to extend that to at least twelve, but would never be able to justify it

 

[Dick Rees]

Re: Question concerning "end fire subs"

I guess the DX38 isn't really suitable for subs, having only a short delay for alignment between horn and midrange in a biamped box. I doesen't really matter what configuration you go for, any configuration that is not a straight cluster requires at least one delay around 4mS. One problem with 3:1 is of course that you need individual amps for all subs, if you have the subs on a big two channel amp, then it is out of the question. I have four channels, but my problem is that I can't set individual right and left delays on the DRPA+ (didn't try too hard), so I ended up just going thru a delay after the x-over. Only got four subs of my own, would really like to extend that to at least twelve, but would never be able to justify it

The DX38 has plenty of delay for doing the subs, even enough to delay an entire system to the backline.......and beyond. The limitation is that it is 2 in/4 out.

 

[Per Søvik]

Re: Question concerning "end fire subs"

The DX38 has plenty of delay for doing the subs, even enough to delay an entire system to the backline.......and beyond. The limitation is that it is 2 in/4 out.

OK, I mistakingly thought that it was limited to alignment in the uS range 0-999 ie, about a foot maximum. Well then, if you are not actually using the x-over for hi-mid, and you can live without aux fed subs, then take the mono sub signal to both bottom outputs and delay one output, no problem ~~:smile: A three way split lead shouldn't be that hard to make if you havent got link outs on your sub amps.

 

[Dick Rees]

Re: Question concerning "end fire subs"

OK, I mistakingly thought that it was limited to alignment in the uS range 0-999 ie, about a foot maximum. Well then, if you are not actually using the x-over for hi-mid, and you can live without aux fed subs, then take the mono sub signal to both bottom outputs and delay one output, no problem ~~:smile: A three way split lead shouldn't be that hard to make if you havent got link outs on your sub amps.

The subs are run off an aux so I can tailor the response to the individual (read varied) groups.

1. New Orleans style strolling horn band w/bass drum and snare/percussion.
2. Faculty/student combo(s) from local jazz school.
3. 44 piece big band.
5. Female vocal duo w/standard combo backup.
6. Solo female w/keys, bass and drums.
7. 6 piece Latin/Cuban jazz combo.
8. Abdul Zuhri (guitar)/ Pepsii Riley (vocal). Full kit, keys w/tracks, bass, sax.

 

[Jay Barracato]

The subs are run off an aux so I can tailor the response to the individual (read varied) groups.

1. New Orleans style strolling horn band w/bass drum and snare/percussion.
2. Faculty/student combo(s) from local jazz school.
3. 44 piece big band.
5. Female vocal duo w/standard combo backup.
6. Solo female w/keys, bass and drums.
7. 6 piece Latin/Cuban jazz combo.
8. Abdul Zuhri (guitar)/ Pepsii Riley (vocal). Full kit, keys w/tracks, bass, sax.

Dick,

My concern would be that many of these acts are going to be unused/unable to deal with strong low end reinforcement. So I would be looking at either Per's 2x2 Cardiod or 3x1 Cardiod model.

I am sure you know this but since several of the acts need little to no low end on stage I would create the punch for the headliner by contrast. I would align the subs level with the tops at first and mix the drums and bass "jazz" style with just kick and overhead on the drums. Go for "thwack" rather than "thud" on the kick.

Then when you get to the second to last act start to boost the subs and re eq the kick. While it won't be as much as all four subs combining, it should still have good impact just by comparison with the rest of the day.

I would bet that would give more impact for the headliner than if the crowd had been listening to a boosted kick all day.

 

[Dick Rees]

Re: Question concerning "end fire subs"

Dick,

My concern would be that many of these acts are going to be unused/unable to deal with strong low end reinforcement. So I would be looking at either Per's 2x2 Cardiod or 3x1 Cardiod model.

I am sure you know this but since several of the acts need little to no low end on stage I would create the punch for the headliner by contrast. I would align the subs level with the tops at first and mix the drums and bass "jazz" style with just kick and overhead on the drums. Go for "thwack" rather than "thud" on the kick.

Then when you get to the second to last act start to boost the subs and re eq the kick. While it won't be as much as all four subs combining, it should still have good impact just by comparison with the rest of the day.

I would bet that would give more impact for the headliner than if the crowd had been listening to a boosted kick all day.

There are only two groups requiring the kick drum to be a significant part of the mix. The rest vary. The whole "adjustment" is down to the aux fed subs.

Clue: The headliner's drummer is using a butt-kicker.......

 

[Dick Rees]

Re: Question concerning "end fire subs"

I'm replying to this post as it appears that I can't reply to my own:

Final after the gig report:

I ended up not using the Cobra II rig due to the promoter not seeing the value-added in upgrading the rig, so I used my 4 EV T-251+ mid/hi's augmented with a pair of Sx300's as a separate "solo PA". SOS all the way with the 300's above the traps and tilted down using toilet shims. Subs were the "End-fire 2" arrangement resulting in a nice, full cardioid delivery out front and very benign bass on stage using 4 Sb180's. The entire system was delayed to the backline except for the solo PA which was delayed to the front of the stage (roughly).

It worked extremely well, aided by a 20-25 mph tail-wind which carried the sound forever down into the next couple of blocks with the entire mix intelligible, albeit lacking in LF content the farther out you got. But I'd say the complete mix went well over 150'. SPL @ FOH (75' out, A slow) was hitting 103 at the peaks. That checks out with the speaker specs and the math, so that's about as good as it gets.

All in all I was very satisfied, especially with the subbage. Thanks to all for the advice, constructive criticism and general support.

DR

 

[Dick Rees]

Re: Question concerning "end fire subs"

Photos from the gig:

dual PA, top speaker on "toilet shim" tilter
cardiod subs
noon: add 3K listeners for the headliner

 

[Art Welter]

Re: Question concerning "end fire subs"

Dick,

Other than keeping anybody from dancing within 8 feet of the stage, what other effects did you notice from the sub array compared to a pair on either side?

Art

 

[Dick Rees]

Re: Question concerning "end fire subs"

Dick,

Other than keeping anybody from dancing within 8 feet of the stage, what other effects did you notice from the sub array compared to a pair on either side?

Art

Budget cuts and lack of production staff resulted in a stage too low to allow the subs to be placed underneath (budget) and the "bicycle rack" crowd barriers got cut (production glitch). There was supposed to be a secure area in front of the stage, but........

On the sonic side of things, the coverage was much smoother over the listening area (width of street plus two sidewalks, probably 70-80', and a crowd depth of150'). But the best thing was to have the LF kept out front and off the stage.

For the headliner we did end up moving two wedges onto the rear pair of subs to get a bit more room on the stage.

All in all I was pleased with the result as was the promoter.

 

[Ivan Beaver]

Re: Question concerning "end fire subs"

I think a lot of the decision on what setup to use should be based on what it is that one wants the subs to do. If the main function of the subs is to give a kick the gut-wrenching quality that we crave, then a centre clustre/array is the thing. If the main function is to provide downward extension for several instruments, and the performance around crossover frequency is important, then it often makes sense to go with tops and subs together. It all depends on what frequency is most important, and wether considerations about power alley and stage volume are important or not.

Lykke til!!

Agreed. it is all about compromise.

Consider this-regarding overall "smoothness". Exactly what does that mean. Yes when you model a center cluster vs a left/right sub cluster-the level is more "smooth".

HOWEVER, it will be louder right in the middle-near the cluster of subs. This may be a good thing in some cases-and a very bad thing in others. In some cases-having variance-but a more "even SPL" is more important.

It all depends on what is trying to be achieved. What works in some situations will not work in others.

That is why each has to be addressed as individual.

In audio there is no "one size fits all" product.

 

[Dick Rees]

Re: Question concerning "end fire subs"

Agreed. it is all about compromise.

Consider this-regarding overall "smoothness". Exactly what does that mean. Yes when you model a center cluster vs a left/right sub cluster-the level is more "smooth".

HOWEVER, it will be louder right in the middle-near the cluster of subs. This may be a good thing in some cases-and a very bad thing in others. In some cases-having variance-but a more "even SPL" is more important.

It all depends on what is trying to be achieved. What works in some situations will not work in others.

That is why each has to be addressed as individual.

In audio there is no "one size fits all" product.

In re the bold type:

Pleasing the promoter. He really likes the cardioid sub sound........as do the musicians on stage.

Edit:

The main problem with the LF response/content/pattern was with headliner engineers boosting things to sound right at the mix position and swamping people in the front and at the "hot" nodes when using L/R subs. Yes, there is now something of a hot spot right up front in the middle, but overall I'd say there's a significant improvement over the rest of the listening area.......

in this instance.