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Topic: Best Practices for a 15" Sub.. Placement and such
SO, I have 2 Mackie Thump 15s, AMAZING Speakers. Going strong for 3 years now and HUGE sound.. I also picked up a 15inch Behrigner powered sub and I know this thing can work well, but mostly, I never need it. The best times Ive had with this is, Tile Floor, keeping it away from the about about 5 feet, using Hi-Pass for the Mains.. Insane sound. but most of the time Ive had this thing out, I lose bass.. Once I take the bass off of the mains and let the sub do the heavy work, my audience has no thump in a setting like a ball room while all my shet on my table is bouncing around. Just looking for best placement and practices with this set up. I'm mostly a club DJ and play through the house systems so I rarely heed my system, but when I do, I want it to sound great! THanks

Posted Mon 15 Jan 18 @ 4:10 pm
I send full signal to my tops. Why would I not use the 15 inch woofer, in the cabinet? I use my subs as added low end. I don't know which Berhinger sub that you have, but it is not going to blow the place away, if you have a large crowd, big room, and kicking club or hip hop. You will need some larger subs, that are capable of delivering lower hz, and higher power. A 15 just adds a little whip cream, if you want the cherry, you will have to go bigger. Placement can help, but I have to go.

Posted Mon 15 Jan 18 @ 5:52 pm
You would still be using the woofer in the top cabs, even if the tops are fed with a high pass signal from a crossover in the sub.

They'd be outputting a mid range signal. That's the general idea with using a sub - it creates a three way system. Low from the sub, mid and high from the tops.

It's always better to have separate drivers for each frequency range. Separating the mids from the lows should give you clearer sound - because you no longer have a single driver trying to cope with vocals and bass simultaneously.

Posted Mon 15 Jan 18 @ 6:01 pm
Ive been thinking of going with an 18sub with more power, but as stated, I rarely ever need a sub.. but when I do.. it needs to perform

Posted Mon 15 Jan 18 @ 6:10 pm
Groovindj, sorry if I was not clear. Of course the woofer is still being used, but as he pointed out, he is losing low end. That's what happens when you send highs and mids to the tops. I don't want to lose any low end, so I send a full signal to the tops, and let the crossovers do their job, I have never ever needed more mid and highs, if anything I lower them.

Posted Mon 15 Jan 18 @ 10:52 pm
groovindj is correct, the best sound will come from splitting the frequency bands up to match the available amount of surface area of speaker driving.
For example; You have 2 x 15" mids = 30" Drive. 1 x Bass 15" = 15" Drive. There is an inherent mismatch in progress.
If you were powering this with active speakers, you would have to run the bass at mighty high volume, as power consumption is very high on low frequencies, it would be hard to match the output of the high/mid with so little air being moved from so little surface area.
A better solution is to double up your bass units to equalise the driven surface area. You can then attenuate the bass to stop booming and clarify the detail and run at a lower cross over frequency.
Remember that high-mid frequencies require far less power.
My personal set up is 4 x 15" bass and 2 x 15" mid/high cabinets run from an electronic 2 way crossover and 2 x 1000w amps. Levels set at approx 7 for bass and 5 for mid/high (Depending on location).
Also remember that standing behind bass cabinets will give you a false idea of the sound as you are out of phase with it and it will sound very boomtastic.

Posted Mon 15 Jan 18 @ 10:58 pm
bigron1PRO InfinityMember since 2010
The sub is just not good enough so AMAHM's suggestion is the best compromise given the equipment. Bass bins should be carefully matched to the tops.
Using AMAHM idea creates a kind of muddy transition from bass to mid but might reinforce the bottom end.

Hm..new subs!

..and if possible put it in a corner with solid walls and let it radiate outwards.

Posted Tue 16 Jan 18 @ 3:21 am
bigron1PRO InfinityMember since 2010
I might try to be creative with speaker placement. Use the stone thrown into a pond model. There will be 3 stones and the places that they land will be such that the waves join together producing little wave cancellation. Maybe the 2 tops in one corner side by side (or one in either corner?) while the sub is in the other corner all tending to point forward. Anyway experiment..but watch out for wave cancellation.

Posted Tue 16 Jan 18 @ 3:11 pm
A Man and His Music wrote :
I don't want to lose any low end, so I send a full signal to the tops.


So you've not heard about comb filtering and time alignment. Another thing to note, mid/top speakers featuring 15" are very poor at upper mids. Only ideal for systems not using a sub. If you're using subs you're much better off with a 12" or smaller for Mid/tops.

Removing the low energy from your Mid/top will give you more head room in your amplifier and allow you to put a bit more through the speaker, as it's not trying to create the frequencies it's not designed for.

If you're sub's aren't adequate enough one could always lower the cross over frequency. Putting more lower frequencies through the Mid/top speakers, with the sub only picking up where the Mid/tops start to roll off.

Lets not forget the cancellations due to reflected sound from the floor and the ceiling. The more put through, the more it cancels. The frequency this happens at is dependent on height, carving huge holes in the frequency response of your system, certain bass notes will simply disappear.

It is considered bad practice to have different speakers producing the same frequencies, into the same area.

Posted Tue 16 Jan 18 @ 10:50 pm
Here's a neat trick... If you get time! Try it with a 50-80hz test tone.

Place the sub where you want most bass, the middle of the dancefloor, dj side, walk around the room, where ever the bass is loudest, place the sub there.

The other problem you will get is the subs not being correctly aligned with your tops. Getting this right is quite a subject. The easiest way is the reverse polarity test but... if your 1 cycle out, it will still pass the test and be completely wrong. We'll save that for another day.

Posted Tue 16 Jan 18 @ 11:00 pm
"So you've not heard about comb filtering and time alignment."

That's funny to me, as I learned most of this from doing club installs in some of the most iconic clubs, with Richard long and Alex Rosner during the 70's. I think most of us are talking about doing parties with full range powered speakers, and powered subs. If you think all of the technical placement is necessary for a party of 150 people at a wedding reception, that think Spotify coming from their iPhone to their earbuds is the best sound, I don't have a problem with that. A powered full range speaker is designed to produce full range, so that is what I send to it. The OP wanted to know why he lost some of the low end from his sound. That's because he only sent mid and highs to his tops. I don't have a problem with that, because that is why you have both options, coming out of the sub. You can choose which ever you want, but I am not playing to a room full of audiophiles. A good powered full range speaker, is good for most of the parties that we do. If you have more people, you will have to bring more sound.

Posted Tue 16 Jan 18 @ 11:28 pm
I don't think it's necessary no. Doesn't mean a newbie asking questions should remain ignorant to the knowledge. You were lucky to of learned this already, I'm only offering light. When it comes to maximising performance, especially if budgets are tight, knowing can be power. There's nothing worse than adding a Sub, running your Mid/tops full range and due to where you place your sub, you're only cancelling the low energy between the 2. Resulting in turning up the bass more, resulting in more cancellation, overdriving your equipment and eventually damage.

I know you're only trying to rescue your comment but there's no need to get defensive or name drop, i have no idea who they are and i'm not about to google them.

The last thing any of us want to do is add equipment and make the sound worse. This happens quite a lot and many often don't even notice. So many buyers making bad choices. The 15" Mid/tops with subs needs to end. Manufactures still make them because people who don't know, following the old skool disco trend, want them.

In this guys situation, as a quick fix, i would likely do as you did. But... I'd be very cautious over placement. Once i added another Sub i wouldn't. Yes that 15" mid is wasted not doing the lower frequencies as it's rubbish at uppers anyways.This is why I said I would lower the cross over frequency. Instead of crossing at 80-100. I'd go 60-80. Those thumps won't do much under 60. Now the clip lights won't come on so early.

This info needs to be spread as much as possible, otherwise the consensus won't change and we'll still be sold far from ideal set ups.

Posted Wed 17 Jan 18 @ 12:10 am
bigron1PRO InfinityMember since 2010
Good stuff.

I will point out once more that solid walls by your speakers provide amplification. Read up on it if in doubt.

Posted Wed 17 Jan 18 @ 1:33 am
bigron1 wrote :
I will point out once more that solid walls by your speakers provide amplification. Read up on it if in doubt.


Kind of but not entirely true. The speaker doesn't magically get any louder. It's the first Law of Thermodynamics. All that is happening is the sound that would of radiated in that direction, where the wall is, won't, adding to the sound, where the wall isn't... Reflected back. For instance, a sub in the middle of the room would radiate say 100dB into the room spread out almost equally in all directions, from the source. The sub in the corner of the room, against the wall, the energy isn't spread out as much, from the source.

It's quite hard to put in words but i hope that makes sense


Posted Fri 19 Jan 18 @ 10:32 am
TearEmUpPRO InfinitySenior ModeratorMember since 2006
mitchiemasha wrote :
It's quite hard to put in words but i hope that makes sense


What you are trying to say is, the sound signal from a sub is omnidirectional.

Sub placement can be fun to play with, depending on the room. When I'm planning a set up, my first thought is, how many guests. Everything else radiates from the number of people attending. No need to bring 5000 watts when 700 will do the trick.


Posted Fri 19 Jan 18 @ 1:03 pm
A whole lot of reading here. My THUMP 15s alone make a great sound a produce a fair amount of pass, just not a chest pounding bass you would wont for a large party. The best set up Ive ever had, same 3 speakers I have no, 2 Mackie Thumps and one 15inch bahringer sub.. Large room, all time. Thumps about 6 feet up, SUB about 5 feet from left wall, 6feet from back all.. the bass was so deep and chest pounding. The placement and room was perfect only in that gig lol

Posted Fri 19 Jan 18 @ 9:47 pm
Here's my take, if your using your own system and it's a pair of tops with a single 15" sub, then you are playing in relatively small venues, what this means is that the people in attendance are going to be extremely close to the speakers, i.e. within a meter sometimes, in this instance if your not running a full signal, that person is only gonna hear mid and hi.

This is the reason I do not use one of these types of systems below:

PS,

Ex Bose 802 user!

Posted Fri 19 Jan 18 @ 10:04 pm
TearEmUp wrote :
What you are trying to say is, the sound signal from a sub is omnidirectional.


Yes but a lot more than that. What i'm trying to say is, it is the use of the wall to reduce the omnidirectional nature of the sub that is said to create the 'extra' energy, there isn't actual extra energy, one has simply redirected some of it.


Posted Sat 20 Jan 18 @ 6:04 pm