eq of t30s and ot12s for bass

EQ guys are using on their cabs/systems. A good starting place if you don't have your own RTA.
Message
Author
User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

eq of t30s and ot12s for bass

#1 Post by tactix »

Hello all I have a question about eq strategies for bass driven music, which in my case is reggae. Traditional reggae sound systems use mid-bass kicks to handle frequencies of say 90- 200hz. I think the idea here is that you have good control over the frequencies that give the visceral punch you expect to feel when listening to dance music. In my case i’m running 4x t30s and 4x ot12s. Presently they are crossed at 100hz.

To get that punch feeling from my system, i have been adding a significant boost to those “kick” frequencies using a parametric eq after i’ve established a baseline with the auto eq from my driverack, following the “recommended” target curve which applies a boost to the bass frequencies.

My questions are two fold:
first, does my strategy seem reasonable to you? Turning down the tops and pushing the whole system harder seems to produce a muddier response- at least inside where I’m currently testing (big concrete and metal roof warehouse space- 45’ wide, 100’ long, 17’ high). This is the first time i’ve tried running this system indoors in a big room. Vplated and corer loaded seemed like too much. The bass got boomy at higher spls. I’m my preliminary test things sound better in the center of the room without boundary reinforcement. I feel like i need to ask more from the deltalite 2512s and need to ease back on the tubas (3012lf).

second, what would the advantages and disadvantages be of having a dedicated set of cabs do work of mid-bass vs
the ot12s doing that and everything else up to the compression driver crossover? Bill has described the use of kick bins as a relic of the 90s. Why?

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: eq of t30s and ot12s for bass

#2 Post by Grant Bunter »

This is recorded music? Or are you doing reggae bands?
I guess it's not really relevant in some ways, but the majority of people I see still using or asking about using kicks bins are doing so for reggae, and are predominantly based in the Caribbean.
Recorded gives you more room to manipulate though.

PA 3+ decades ago for reggae (and lots of other genres) were more often than not double 4 ways (sometimes with mixes of horns such as W bins for subs and Scoops for low mids, and direct radiators for other stuff). Double 3 ways were used a lot as well.
One can only assume that the necessity for kick bins evolved from an inherent lack of response from the mids, which, with kicks bins, was partially solved. Highs were often large horns with 2" drivers +/- rings as well.
Double 3 or 4 ways were never about fidelity as such, more about sheer SPL.
More modern Subs/tops combinations are superior in design, and hence response is better.
Less amps, less cabs, less speaker cables, less signal cables, simpler crossovers, less to go wrong, and a smaller truck with less crew.

Back to your particular situation.
Have you ever run some of your fav tracks through audacity to see what actual content there is in reggae as recorded?
If not time to do so.
The reason I suggest this is that you might find there is no elevation in your suggested kick bin region response on the recording.
If it's not there already, it makes it much harder to put there, and you should ask yourself why you want to put it there.
If it is there already, then you can come back to how your current PA is set up not reproducing that.

Each component or layer eg subs/kick bins/tops or mains requires it's own band pass, you should never have 2 different design cabs trying to reproduce the same content for a number of reasons, which is why it's recommended here to use steep slopes.
Horn subs tend to filter harmonics. Is this an issue? Well not for clean warm enveloping sound, but fundamental E string on a 4 string bass is say 40Hz, the 1st harmonic would be 80Hz and present with direct radiators, but not horns subs.
Similarly, kick drum beater is say 50-70Hz for the fundamental, 100-140Hz for the 1st harmonic.
And so on.

So, perhaps increase kick thump some by upping the fundamental via EQ (sweep it to find the actual frequency).
The same for 80hz, 125Hz (which I invariably cut some in live music), 200-250, and work your way up from there.

Keep your target curve saved, drop anything below 50Hz to flat, re auto EQ and see how that sounds too, that should tame some of the bass boominess (though a lot of that is 125Hz and 250Hz, sometimes 400Hz as well).

I would try all this, and more like moving the cross point to 90Hz, before extensively exploring a kick bin solution.

Sorry about the essay...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28698
Joined: Tue May 02, 2006 5:59 pm

Re: eq of t30s and ot12s for bass

#3 Post by Bill Fitzmaurice »

tactix wrote: Sun Mar 26, 2023 10:54 pm Bill has described the use of kick bins as a relic of the 90s. Why?
Because modern systems work better. When kick bins were invented most tops couldn't reach below 200Hz with high output. They needed to be augmented in the midbass. Modern systems don't. As for the tonal balance, that's done in the studio. Reggae will typically have very little true bass content, with a lot in the 60-200Hz range. That's because the bass cabs and PA cabs used in Jamaica back in the day, and today for that matter, were incapable of going below 60Hz. A faithful reggae recording will have major content in that 60-200Hz range. This is an RTA I took in the FOH of 'The Wailers' through a million dollar system, with no kick bins:

Image

That's what your system content should look like playing reggae, be it recorded or live.
If there's a deficiency in your system where reggae is concerned it's the subs. For a system dedicated to reggae you'd be better off with T39s, which have higher sensitivity in the upper bass where you need it, less in the low bass where you don't.

User avatar
Seth
Posts: 2816
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: eq of t30s and ot12s for bass

#4 Post by Seth »

tactix wrote: Sun Mar 26, 2023 10:54 pm ...Vplated and corer loaded seemed like too much....
Great problem to have! Easy to fix.

Every new sub and top placement will require level and EQ adjustments to restore the response as close as possible your target response curve. It's not clear whether this is something that you did or didn't do. But, if you tuned the system with the subs placed in traditional spots, then v-plated and corner loaded the subs... it makes sense that they would seem like too much. In this particular case, the feed to the sub amp would need to be attenuated about -15dB to have the output of the subs match the output of the tops again. Plus, another EQ tweaking to remove boosts that occurred in the initial (poor sub placement) EQing in an ill fated attempt to fill dips in the response caused by poor sub placement cancellations.
...In my preliminary test things sound better in the center of the room without boundary reinforcement...
It's not the case every time, but more times than not, corner loaded subs will provide the most even response throughout a large room. If you thought it sounded better in the middle without boundary reinforcement, the question is, why and/or what contributed to that particular conclusion? It's really difficult to say without being there and taking measurements. Was it, in fact, better than without boundary loading? Or, was it just better in the middle than in other places in the room?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

Re: eq of t30s and ot12s for bass

#5 Post by tactix »

Thanks for your response Grant. Appreciated.
Grant Bunter wrote: Mon Mar 27, 2023 12:19 am This is recorded music? Or are you doing reggae bands?
I guess it's not really relevant in some ways, but the majority of people I see still using or asking about using kicks bins are doing so for reggae, and are predominantly based in the Caribbean.
Recorded gives you more room to manipulate though.
Recorded music with live mcs primarily.
Grant Bunter wrote: Mon Mar 27, 2023 12:19 am PA 3+ decades ago for reggae (and lots of other genres) were more often than not double 4 ways (sometimes with mixes of horns such as W bins for subs and Scoops for low mids, and direct radiators for other stuff). Double 3 ways were used a lot as well.
One can only assume that the necessity for kick bins evolved from an inherent lack of response from the mids, which, with kicks bins, was partially solved. Highs were often large horns with 2" drivers +/- rings as well.
Double 3 or 4 ways were never about fidelity as such, more about sheer SPL.
More modern Subs/tops combinations are superior in design, and hence response is better.
Less amps, less cabs, less speaker cables, less signal cables, simpler crossovers, less to go wrong, and a smaller truck with less crew.
I appreciate the summary - thanks. Extrapolating from what you've laid out, I think what you're implying is that I should be able to eq my way through this and that asking the OT12s to reproduce a significant amount of lower-end content is not going to compromise their ability to reproduce mids and highs (before the cross to the compression drivers).

Grant Bunter wrote: Mon Mar 27, 2023 12:19 am Back to your particular situation.
Have you ever run some of your fav tracks through audacity to see what actual content there is in reggae as recorded?
If not time to do so.
The reason I suggest this is that you might find there is no elevation in your suggested kick bin region response on the recording.
If it's not there already, it makes it much harder to put there, and you should ask yourself why you want to put it there.
If it is there already, then you can come back to how your current PA is set up not reproducing that.
I'll have a look and listen to some reference tracks this way before I head out for another test session. As I mentioned, I have been able to get more kick by using a parametric eq but having a clear picture of the frequencies of the content I 'm working with before I start those adjustments on the PA is a great suggestion.
Grant Bunter wrote: Mon Mar 27, 2023 12:19 am So, perhaps increase kick thump some by upping the fundamental via EQ (sweep it to find the actual frequency).
The same for 80hz, 125Hz (which I invariably cut some in live music), 200-250, and work your way up from there.
I take this to mean EQ boost on the fundamentals and then on the harmonics as well. I'll try that
Grant Bunter wrote: Mon Mar 27, 2023 12:19 am Keep your target curve saved, drop anything below 50Hz to flat, re auto EQ and see how that sounds too, that should tame some of the bass boominess (though a lot of that is 125Hz and 250Hz, sometimes 400Hz as well).

I would try all this, and more like moving the cross point to 90Hz, before extensively exploring a kick bin solution.
So, I'll try these eq strategies but a question about saving the target curve. I haven't figured out to load my own target curve that the auto eq adjusts to. Results from auto eq results are saved but is there a way to load custom target eq curves? My venu360 has three built in target curves - recommended (boost on lower end), flat, and reflective room (which is think tames the higher registers). My thought about applying a custom curve has been to auto eq flat and then apply a graphic eq. curve. Is that the way to do it?

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: eq of t30s and ot12s for bass

#6 Post by Grant Bunter »

Cool, giving you something to work with.
The Otops should be good down to 90Hz and still do mids.
Yes, I think it's about EQ.

Save what you've done already as eg SystemTryout (then later you can do some AB comparisons). Create a custom curve (once you've worked out what that should be), save ( I call my custom curve System tune), then auto EQ to that, so you're adjusting your custom curve based on room response. If you're going back to the same space again, after auto EQ, save the result (as eg boomyshed1). Next time you go there, hit recall/scroll/apply. You should be up and running.

New venue, recall System tune apply/auto EQ save (eg boomyshed2).

You're going to have to be careful with regard to feedback with live mikes if you've boosted frequencies (especially the 1st harmonics I described earlier) in your EQ setup, and the same attention may need to occur for monitors.
It's all good, and it's all a learning curve.

Tell us what you find...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

Re: eq of t30s and ot12s for bass

#7 Post by tactix »

Bill Fitzmaurice wrote: Mon Mar 27, 2023 7:06 am
tactix wrote: Sun Mar 26, 2023 10:54 pm Bill has described the use of kick bins as a relic of the 90s. Why?
Because modern systems work better. When kick bins were invented most tops couldn't reach below 200Hz with high output. They needed to be augmented in the midbass. Modern systems don't. As for the tonal balance, that's done in the studio. Reggae will typically have very little true bass content, with a lot in the 60-200Hz range. That's because the bass cabs and PA cabs used in Jamaica back in the day, and today for that matter, were incapable of going below 60Hz. A faithful reggae recording will have major content in that 60-200Hz range. This is an RTA I took in the FOH of 'The Wailers' through a million dollar system, with no kick bins:

Image

That's what your system content should look like playing reggae, be it recorded or live.
If there's a deficiency in your system where reggae is concerned it's the subs. For a system dedicated to reggae you'd be better off with T39s, which have higher sensitivity in the upper bass where you need it, less in the low bass where you don't.
Thanks for this Bill. I am using "reggae" fairly loosely here. A lot of the UK dub music that's produced these days is basically EDM with a reggae vibe so it has significant lower bass content. Some modern reggae productions go low too but in general, I hear what you're saying. As luck with have it, a retiring sound man gifted me four unloaded T39s, so if I can find some drivers for them (anyone want to sell me some used 3012lfs?) I'd be setup to do a comparison which would be super interesting (for me anyway).

User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

Re: eq of t30s and ot12s for bass

#8 Post by tactix »

Seth wrote: Mon Mar 27, 2023 10:14 am
tactix wrote: Sun Mar 26, 2023 10:54 pm
...In my preliminary test things sound better in the center of the room without boundary reinforcement...
It's not the case every time, but more times than not, corner loaded subs will provide the most even response throughout a large room. If you thought it sounded better in the middle without boundary reinforcement, the question is, why and/or what contributed to that particular conclusion? It's really difficult to say without being there and taking measurements. Was it, in fact, better than without boundary loading? Or, was it just better in the middle than in other places in the room?
Thanks for your response Seth. I had another chance to get in to the room and do another set of tests. We tried a number of different configurations, both of the subs and their placement in the room. I did not have the forethought to take detailed notes but I have identified a number of issues I'm hoping you all might have insights on.

Placed in the corner was probably the worse configuration - the sound from the subs was muddy, whether I crossed over at 90hz or 100hz. Moving the subs to the middle of the short (45') wall (again the room is 100' long by 45' wide by 17' tall) I started to notice a few things. First, at high volumes the bass started to double up - instead of thump, thump, thump , it went thump-thump, thump-thump, thump-thump. I gather this is a reflection from the room. I also notice that the bass was lagging behind the tops. Putting a delay on the tops improved things but I never go them to quite sound right. I suspect the muddiness in the corner was related (and lack of kick that I was complaining about earlier) to this reflection. Does this make sense? Things improved when I placed the subs in the center of the long (100') wall. Doubling up seemed to go away and the timing issue didn't seem to be present or was less pronounced. It was getting late at this point so I'm not able to give a detailed account of all the eqing I tried, but at 90hz on the sub crossover the sound was much thinner than 100hz. Next up I'm going to try autoequing flat, then applying a "target" curve using the graphic eq, followed by a parametric eq on the tops to try to get more bass response and tame the highs. Right now, regardless of the autoeq target curve used (are these user modifiable? There seems to just be three built in ones on my unit), the tops scream before I can get enough lower end from them.

Any thoughts on what's happening in that room with the doubling up and delay or on my planned approach for the next test?

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28698
Joined: Tue May 02, 2006 5:59 pm

Re: eq of t30s and ot12s for bass

#9 Post by Bill Fitzmaurice »

RTA measurements? Without them one can't do more than guess at what's happening.

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: eq of t30s and ot12s for bass

#10 Post by Grant Bunter »

tactix wrote: Wed Apr 05, 2023 3:32 pm Next up I'm going to try autoequing flat, then applying a "target" curve using the graphic eq, followed by a parametric eq on the tops to try to get more bass response and tame the highs. Right now, regardless of the autoeq target curve used (are these user modifiable? .
Please reread my last post.
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Seth
Posts: 2816
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: eq of t30s and ot12s for bass

#11 Post by Seth »

tactix wrote: Wed Apr 05, 2023 3:32 pm ...Placed in the corner was probably the worse configuration - the sound from the subs was muddy, whether I crossed over at 90hz or 100hz...
Were the amp levels identical when the subs were placed in each location? I assume they were. For recorded music, too much bass/not enough tops makes it sound muddy. When you put the subs in the corner, you need to adjust the subs level down or the tops level up a fair amount. I prefer to keep the sub levels static and adjust the tops to match the output of the subs in the listening space.

Here's the quick and dirty way I do it... I run a sine wave at the crossover frequency through just the subs and measure the SPL at any specific location in the primary listening area. Then without making any changes to system volume, I mute the subs, unmute the tops, and adjust the tops (best done in the DSP processor) gain until the SPL reads the same as the tops did at the same location I measured at before. This will get you pretty close, quick and easy. You can download free DSP apps on your phone.

Not sure about the reflections. Would have to hear them. Got a video?

Bill's right, to really be able to provide quality advice, RTA measurements are invaluable.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

Re: eq of t30s and ot12s for bass

#12 Post by tactix »

Grant Bunter wrote: Thu Mar 30, 2023 7:42 am
Save what you've done already as eg SystemTryout (then later you can do some AB comparisons). Create a custom curve (once you've worked out what that should be), save ( I call my custom curve System tune), then auto EQ to that, so you're adjusting your custom curve based on room response. If you're going back to the same space again, after auto EQ, save the result (as eg boomyshed1). Next time you go there, hit recall/scroll/apply. You should be up and running.
Hi Grant. Save what though? The combination of all the configurations I've applied (crossover, limiter, parametric etc.)? Auto Eq isn't saved in saved presets as far as I can tell (so says the manual) though the last measurements are persistent across boots it seems. How do I build a custom target curve from this saved configuration and where would this be saved? I could run a frequency sweep through the configured system and record the results with an RTA but then what do I do with that? Target curves for the venu360 seem to be built-in only an not user configurable (or I'm missing something).

User avatar
tactix
Posts: 82
Joined: Sat Oct 21, 2017 4:38 pm
Location: Providence, RI
Contact:

Re: eq of t30s and ot12s for bass

#13 Post by tactix »

Seth wrote: Wed Apr 05, 2023 7:45 pm
Were the amp levels identical when the subs were placed in each location? I assume they were. For recorded music, too much bass/not enough tops makes it sound muddy. When you put the subs in the corner, you need to adjust the subs level down or the tops level up a fair amount. I prefer to keep the sub levels static and adjust the tops to match the output of the subs in the listening space.
That's basically the approach I was taking.
Seth wrote: Wed Apr 05, 2023 7:45 pm Here's the quick and dirty way I do it... I run a sine wave at the crossover frequency through just the subs and measure the SPL at any specific location in the primary listening area. Then without making any changes to system volume, I mute the subs, unmute the tops, and adjust the tops (best done in the DSP processor) gain until the SPL reads the same as the tops did at the same location I measured at before. This will get you pretty close, quick and easy. You can download free DSP apps on your phone.
Cool - I'll try this as a way of matching the volume of the the tops and subs. I've been using the level assist wizard. Not sure what I would need a DSP app for since the driverack is a dsp and can produce an RTA measurement graph. Is there something I'm missing?
Seth wrote: Wed Apr 05, 2023 7:45 pm Not sure about the reflections. Would have to hear them. Got a video?
No - next time I'll try to do that.
Seth wrote: Wed Apr 05, 2023 7:45 pm Bill's right, to really be able to provide quality advice, RTA measurements are invaluable.
A measurement of what though? A frequency sweep? Recorded music demonstrating the issue? I could make a video of the RTA graph from the driverack with the audio on one channel and the original source on the other . What's most useful?

User avatar
Seth
Posts: 2816
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: eq of t30s and ot12s for bass

#14 Post by Seth »

tactix wrote: Wed Apr 05, 2023 8:59 pm A measurement of what though? A frequency sweep? Recorded music demonstrating the issue?
Pink Noise
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: eq of t30s and ot12s for bass

#15 Post by Grant Bunter »

There should be a bunch of presets, eg Mono Subs/stereo mains, stereo subs/stereo mains, 3 way etc etc.
Pick one of these presets that you'll never use, save into that and rename it as eg systemtryout. Yes. Everything you've done to date, well no, it will only save the last iteration of all you've been doing.

Now setup a custom installation (no wizard), with eg mono subs and L+R if that's what you're doing. Create your cross points again.Create your target curve at this stage. Creating a target curve requires you to know what to boost and what to cut based on cab response, which in this case is ok because your cabs response charts are in the SPL section. Print each chart, draw a pencil line roughly half way inbetween the peaks and troughs for the bandpass being used. Anything above the line pull down, anything below the line bring up. That's roughly flat (+/- Seth's gain matching).
Now save this as eg Systemtune in another preset you'll never use.

Recall that preset and check it.
Auto EQ ends up with a GEQ curve after it's altered room response to your target curve.
So hit auto EQ, then tweak by ear based on some of what we've discussed already. Save in another preset you'll never use as eg Venue1

Now go through EQ with your monitors.

BTW muddy could be, as suggested already, imbalance in subs and mains, or too much of around 400Hz. Or a combination of both.

You should be able to get crystal clear audio with your cabs. Work at it until you do.
Once you've got it crystal clear at volume, you can then start messing with it to suit your preferred genre.

Hope that's clearer...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Post Reply