Booming bass bin

[gsc1ugs]

I gigged last night and more or less turned off the SR TECHNOLOGY 18 SUB

it was booming and horrible, never noticed it like that but it seems i get booming rather than a thick thud.

I have no crossover and the bin has no other tech to make changes, i come out of one dxr15 using thru, any ideas please?

[Sam Spoons]

The sub almost certainly has a built in LPF so that is unlikely to be the problem. Have you got the 'HPF' switched in on the DXR15s? And the HPF on the vocal channel on the mixer (assuming it has one, always have it switched in*).

The most likely problem though is positioning, if the sub is in a corner or up against a wall it will be more 'efficient' so more likely to excite room resonances, moving it even a few inches can help. You might notice the bass coming and going as you walk around the room during the soundcheck, try to find a spot for the sub that gives the most even sound. People filling the room will have limited effect on the low end but will absorb some of the HF so you'll turn it all up a bit which will emphasise the bass some more.

* the boominess is probably feedback through the vocal mix which the HPF will help reduce or possibly even remove completely.

[gsc1ugs]

The sound is wooly if you know what i mean, like a blocked head

[AlecSp]

I'll say it again, though it's been said many times in your many, many threads that are starting to dominate this forum, you need on-site help. You're out of your depth to sort your problems out by yourself. An experienced person on-site may suggest some practical quick fixes that will help reduce your problems, and could demonstrate how suitable replacement kit might work even more suitably for you.

Without doing this, you'll carry on struggling, carry on with disappointing sound, and carry on asking questions whose answers you don't agree with.

This doesn't need to be a permanent arrangement, but a small investment in a skilled resource to see/hear your challenges and work with you to resolve them could achieve infinitely more than you've managed so far.

[Sam Spoons]

The sound is wooly if you know what i mean, like a blocked head

To me that is a different thing to boomy bass implying a loss of HF?

Alex is right you know, if you could get some one to one help...........

[CS70]

The most likely problem though is positioning

This.

What size was the venue?

Was also probably too loud. You simply can have only so much of low frequency in a limited space before things start to go wrong.

[gsc1ugs]

Venue big 50m x 80m

ps: I'm not going down the road of hiring someone in, im on here to get educated i thought that was its purpose, too many complications arrive when hiring in on a venue 2.5hrs away, noone will want to travel that distance for the money i can pay unless its bruce springstien with mega bucks

[Sam Spoons]

We had a similar issue in a smaller but still fairly big venue (250 capacity) a while ago and we literally moved the sub about 12" away from the wall which solved it.

[CS70]

Venue big 50m x 80m

Yeah then most likely the position. Did it happen both with and without the audience? We’re they seated?

[Sam Spoons]

Just to add the front row were experiencing huge booming bass, the mix position ¾ the way back was slightly bass light, moving the sub evened things up a lot.

[gsc1ugs]

Yes boomy both with and without people, i had it more or less turned off at the end of the night, 12">? its that critical? i've vouched not to use it again but from what your telling me will give it a go, is there some tech out there that helps with room, space, analysis etc? only thing i remember which is on another thread is this autothingymebob, you plug a mic in and off it when sussing the room for the graphic equaliser?

[CS70]

Yes boomy both with and without people, i had it more or less turned off at the end of the night, 12">? its that critical? i've vouched not to use it again but from what your telling me will give it a go, is there some tech out there that helps with room, space, analysis etc? only thing i remember which is on another thread is this autothingymebob, you plug a mic in and off it when sussing the room for the graphic equaliser?

I asked since masses of people are actually decent low freq absorbers...

So another possibility is a feedback loop with some other mic on stage. Once we had a similar issue because of the (mis)positioning of a guitar amp mic which was picking up the woofer and making it impossible to turn it up at all. Low freqs and reflections get everywhere on stage so most other mics should be hi passed.. but sometimes that's not possible, like in a vocal mic (I hate singing in a hi-passed mic as most desks hi pass too high) so again relative position of mics can be crucial. Basically you debug adding mix one at a time and when u find the culprit, either move the mic or the woofer.

[gsc1ugs]

Ok will try it, the room by the way did not have a stage it was one flat floor for everyone, do i need a crossover? my desk is a simple see below....
https://images.reverb.com/image/upload/s--Oj4cJL8_--/f_auto,t_large/v1557046242/qo59gfdhweicpwe6hov8.jpg

[Sam Spoons]

Have you got the 'HPF' switched in on the DXR15s? And the HPF on the vocal channel on the mixer (assuming it has one, always have it switched in*).

Have you done both the above?

[James Perrett]

If this is the Sub 18A then both of the main outputs of your mixer need to go to the sub and then the DXR 15's should be connected to the X-Over Out connectors on the sub. X-Over is short for crossover so your sub already incorporates a crossover which you should be using. If you don't feed the DXR 15's via the sub then they will also be outputting bass which will make the sound very bass heavy and probably uneven.

As others have said, a small movement of the sub can make a big difference - especially if the sub is near a wall.

[James Perrett]

The sub almost certainly has a built in LPF so that is unlikely to be the problem. Have you got the 'HPF' switched in on the DXR15s? And the HPF on the vocal channel on the mixer (assuming it has one, always have it switched in*).

The sub has a built-in crossover so no need for HPF on the DXR15's if everything is connected correctly - it would only confuse things.

[Hugh Robjohns]

I'm not going down the road of hiring someone in, im on here to get educated i thought that was its purpose...

Yes and no.

Clearly there are very helpful people here who know what they are talking about and are willing to share that knowledge. And that's great. I think all of us here have learned a lot over the years from each other...

But at the same time, there is a great potential for cycles of confusion and frustration resulting from misrepresentation of situations, equipment and underpinning knowledge (accidentally or deliberately), leading to further misunderstandings and confusion....

For example, a questioner may not describe the true situation accurately -- perhaps because they don't appreciate the relevance of certain elements and facts -- or leave out critical details, leading to false assumptions on the part of the respondents and inappropriate advice being given, and thus more confusion and unhappiness.

Or advice given might be misunderstood or applied inexpertly, again leading to disappointment and confusion, and more questions now based on more misunderstandings.

The inevitable result is the spiralling cycle we see in your own posts which cover the same basic ground over and over again, randomly trying new things or exploring new directions without any real understanding and application of the required principles and techniques needed to achieve the desired goals.

I've lost track of the number of mics, mixers and speakers that have been discussed, and apparently bought, tried and discarded... When, in reality, most systems can deliver reasonable results if used appropriately and skilfully. But these things are hard -- if not impossible -- to learn just from remote words on a screen.

In contrast, an hour or two spent in the company of a professional or experienced amateur who could demonstrate the best practices and problem solving techniques, and answer specific practical questions face to face, and find an appropriate solution for your specific situations, requirements and expectations would be far more effective than years fumbling around in any forum debating half-understood concepts while drowning in a sea of frustration.

Don't get me wrong -- I absolutely applaud your desire to learn and master this all yourself. But I can sense the growing frustration and confusion, and so I would urge you to seek out someone who could show you in person exactly what is possible for given budget levels, and what is actually required if it is employed correctly and intelligently in each situation. It would be a very worthwhile investment in my opinion.

H

[Sam Spoons]

If this is the Sub 18A then both of the main outputs of your mixer need to go to the sub and then the DXR 15's should be connected to the X-Over Out connectors on the sub. X-Over is short for crossover so your sub already incorporates a crossover which you should be using. If you don't feed the DXR 15's via the sub then they will also be outputting bass which will make the sound very bass heavy and probably uneven.

As others have said, a small movement of the sub can make a big difference - especially if the sub is near a wall.

True, and how I would rig it. I was going with the OP's wiring scheme though.

Using the crossover in the sub avoids a mismatch between the separate filters in the sub and DXR. But the HPFs in the DXR would improve matters significantly with the OPs wiring scheme.

[James Perrett]

But the HPFs in the DXR would improve matters significantly with the OPs wiring scheme.

The OP's wiring scheme could cause all sorts of confusion. Given all the confusion already I think it would be better to make sure everything is running as it should be otherwise we're going to be subjected to an even longer stream of 'why doesn't this work' posts.

[Sam Spoons]

[gsc1ugs]

This is back of my sub,

https://images.app.goo.gl/sqUarZbugo6hmq6G9

[Music Wolf]

The crossover on the sub appears to be fixed at 120Hz

https://www.musix.com/de/en/SR-Technology-STW-1000A-BLK-Black-162876.html

[Sam Spoons]

I can't read the legends on the panel so don't know what the switches do but, as James suggests, connect both mixer outputs to the L & R inputs on the sub and connect the X-Over outs to the inputs on the DXR15s. Set the DXR15 HPF and D-Contour switches to 'off' and the HPF (below the gain on the mixer) button to on and you should be good to go.

[shufflebeat]

I'm not going down the road of hiring someone in, im on here to get educated i thought that was its purpose...

Yes and no.

+Yup.

With a small amount of genuine understanding a lot of apparently conflicting advice can be assessed in context and seen not to contradict.

One other point, when you're dealing with an appropriate, well matched system a lot of the donkey work has been done for you during the design process. When you cobble together elements from different sources you need to understand the principles and the strengths/weaknesses of every element just to create a level playing field.

We had a little 3 day punk fest in the days where those were fresh and new and no butter advertising was involved. The first few days the sound was abominable (we convinced ourselves it was the goal, it wasn't). The third day was headlined by the Undertones. Feargal Sharkey walked into the hall and without speaking to anyone went straight to the PA, stuffed some spare T shirts into the H/H horns and pointed them to the back wall. He rewired the rest of the speakers through the H/H's filters and disconnected half the midrange speakers and the graphic EQ if memory serves.

That was my first experience of somebody knowing what they were doing. The gig was very loud and very sweet.

[funky54]

You have a number of questions, your trying to isolate through different threads.

I think all of your threads are 1 topic. What should you use for a system? The individual threads are going to provide non-cohesive advice pulling you in different directions.