Open face or bass bin

[bill h]

In the band I play in, we have a PA. We have JBL's for the speakers, the bass bin's are MPro MP255S Subwoofer . And for the tops we have SF25 Dual 15” 2-Way Speaker Cabinet . The amps we use are Pevey or Mackie with more power than we need.

The problime is we have a hard time getting the "in your chest, moving THUMP"? Do we need to trade these for the open Faced 18" speakers MP418S 18” Subwoofer, or add anther set of MPro MP255S Subwoofer ?


ANY Idea's or sugestions we be a huge help!!! thanks.

P.S We play cover tunes in the rock style, STP, Bush, Greenday, Black Crows, Santana,

We have used PRO sound guys and we still can't get the "in your chest, moving THUMP"

 

[Wes Whitmore]

I dont know for sure, but I would assume that your drums aren't giving you the sound you are looking for. Are you using a compressor? Is your kick drum one that is designed for a kickdrum? The compressor is vital...
Tuning the kick is also very important. Some people install rings in the front kick drum skin so you get the mic into the compression zone.

 

[bill h]

Originally posted by Wes Whitmore
I dont know for sure, but I would assume that your drums aren't giving you the sound you are looking for. Are you using a compressor? Is your kick drum one that is designed for a kickdrum? The compressor is vital...
Tuning the kick is also very important. Some people install rings in the front kick drum skin so you get the mic into the compression zone.

We have two EQ's , a compressor, and a noise gate for the FOH sound. I assume that you mean a mic for the bass drum? Yea, we have a Sure SM?? drum mic. (don't know the number off hand. I know it's for a bass drum). As far as the rings go I don't fallow? are you talking about the way the mic is mounted to the drum? If so we have the bars that clip to the head and a bar goes into the drum itself? I don't think it' how the drum is tuned, but more to the "air" that is moved from the speakers.

 

[bill h]

bump

 

[jondog]

Chest thumping requires too much power, a good kick drum mic like the AKG that looks like a football, a compressor, and a noise gate. All of the drum mics should be gated so that there is no ring. Your drummer should know or be able to learn about the rings etc. that can be put on the head to increase thump.

 

[bill h]

Originally posted by jondog
Chest thumping requires too much power, a good kick drum mic like the AKG that looks like a football, a compressor, and a noise gate. All of the drum mics should be gated so that there is no ring. Your drummer should know or be able to learn about the rings etc. that can be put on the head to increase thump.

We have a four channel gate. Thanks for the help, but is it because we don't have the "force from the speaker cone" pointed at the Front of house"?

bump

 

[jondog]

Maybe, I don't think so, but I'm not sure. Those subs should be good. What size rooms are you playing? Folded bins are generally designed to send bass further away, if you want thump in a smaller space then maybe you do want the frontloaded cabs.

Really though, make sure you have the comp and gate set up right. Just one comp for the whole PA? Putting it across the main outs doesn't help the kick much, you've got to dedicate a comp channel to the kick (insert?) using a fast attack and set almost to limiting. Then have the gate clamp down so it doesn't ring, it just thumps.

Tuning the drum is also good advice. I've played w/ some drummers whose kick goes booooooom instead of BOOM. Sometimes putting a pillow or two inside can help kill the ring. Also, changing the beater can make a big difference -- they come in a lot of different materials, tell your drummer to find out which one will give a tighter hit. There are also little pads that go on the head where the beater hits . . . If he can't find out, maybe start a thread asking some of the drummers here on TB.

 

[Petebass]

Originally posted by jondog
Folded bins are generally designed to send bass further away, .

Those subs aren't folded horns. They're actually a bandpass design, meaning they dont fire directly into the listening area. Instead they fire upwards or downwards into a seperate chamber. They're actually more efficient (louder) than forward facing speakers but at the expense of frequency range. They only operate in a narrow band of low frequencies which is why they kick harder.

How many of these subs are you using? My guess is that you're not using enough of them. Looking at those mid-highs, I'd want to use at least 4 of those subs - 2 wont produce anywhere near enough SPL to compete with thise mid-highs. The physics of low frequencies sucks a bit in that you need a lot more power to get equivalent volume. That's why your 400W bass amp isn't as loud as your guitarist's 100w marshall. That same applies to PA. When you go to gigs where the kick is smacking you in the chest, they are generally using brute force - lots of subs cabs, lots of power amps. Have a look at any concert size PA and there are always something like 10 Subs for every 6 mid-high cabs.

 

[bill h]

Originally posted by Petebass
Those subs aren't folded horns. They're actually a bandpass design, meaning they dont fire directly into the listening area. Instead they fire upwards or downwards into a seperate chamber. They're actually more efficient (louder) than forward facing speakers but at the expense of frequency range. They only operate in a narrow band of low frequencies which is why they kick harder.

How many of these subs are you using? My guess is that you're not using enough of them. Looking at those mid-highs, I'd want to use at least 4 of those subs - 2 wont produce anywhere near enough SPL to compete with thise mid-highs. The physics of low frequencies sucks a bit in that you need a lot more power to get equivalent volume. That's why your 400W bass amp isn't as loud as your guitarist's 100w marshall. That same applies to PA. When you go to gigs where the kick is smacking you in the chest, they are generally using brute force - lots of subs cabs, lots of power amps. Have a look at any concert size PA and there are always something like 10 Subs for every 6 mid-high cabs.

Thanks for the help!!! We have Two of the subs and two of the high packs.

Sounds like we may have to go out and get another set of bass bins ($600 per side and $700 for an amp) Do you think that we should get the MPro MP255S Subwoofer or theMP418S 18” Subwoofer Or is there something else you think would be better? I want to stay with the JBL brand but don't have to.

I wish the bars we played at had there own house system

 

[Petebass]

A Double 15 Bandpass Vs a single forward firing 18"???? I'm leaning toward another pair of bandpass. But as my sig says, this is one where you should really listen to them back to back and make a decision that way.

Are you open to a suggestion that's a bit "out there"? If so read on.

Before you spend any money, try this - set up your PA as normal and play a CD through it. Then turn the mid-highs down gradually at the power amp until the bottom end starts to sound louder than the mids and highs. Now that you've got some apparent thump, you need to decide if you can get away with this new reduced volume at a gig.

Now I did say this idea was out there, and the answer may very well be that the overall volume is now too quiet. But maybe, just maybe the new volume works better. It costs nothing and may save you $1,300, so it's worth a shot in my opinion.

 

[bill h]

we've done all the EQ things... you can just have the bass hitting and it still does not give you that "in your chest move your paints type bass"(not loud just that you can feel it)


P.S. I sent a link of this to JBL to see if they can help.

 

[jondog]

Petebass isn't talking eq, he said to turn down the mains at the poweramp until the balance w/ the subs is where you'd like it to be. This is good advice!

 

[Petebass]

I think I confused the issue by using the term "mid-highs" instead of "top boxes". Pardon my Austrailian-isms

What I was trying to say is turn the top speakers down at the poweramp.

 

[Chad Michael]

How much power are you feeding to each of the MP255S?

Are you familiar with the term "power alley"?

Have you experienced how low end varies dramatically as you move about the listening environment?

Also, I don't recommend the MP418S if you are seeking a heavy thump-in-the-chest sound. Although it is a nice sub and would add much needed low end to a system that lacks low frequencies, the enclosure simply is not big enough for what you are trying to do. I have heard from pro sound forums that this is true. The larger SR series 18" sub is in a bigger enclosure, and it can punch harder.

Tip - if the amplifier or crossover in your subwoofer system has a high pass filter (at say 30, 40, 50 hz) you can use the filter to conserve power and punch, by sloping off subsonic frequencies. Simple comparison:

High pass filter on:
You can make a subwoofer dance with a 1/2" of cone travel and punch hard (since the power is concentrated in a more audible, 'punchy' range and amp power is not being wasted on subsonics)

High pass filter off:
Your subwoofer is jumping wildly with 1" of cone travel and sounding wimpy (power amp is trying to deliver frequencies below 30 Hz and wasting power in the process)

Note - measurements are approximate, and for the sake of explanation.

Oh, and it goes without saying... I agree with Pete.

 

[Pete]

I'd look at replacing the 255s with a pair of dual 18" speakers (JBL SR4719's). The 255s is only 300w RMS of power each, not much for sub work. The MP418s is 660 into 1 18 but the box design is too small. I'd look at 2x 4719s and 1 crown CE4000 (no ce2000's) for power. Even the RMX5050 will do nicely. I have a Carver PT2400 for sale too.

pete

 

[Skorzen]

'd look at replacing the 255s with a pair of dual 18" speakers (JBL SR4719's).

I agree with this. I work with a friend of mine doing quite a bit of live sound, and he just picked up a pair of these not to long ago. We were using them in a ~400 seat theater once and forgot to hookup the amp for one side, so we were only running one sub when we first set up the system. The only reason we found out was because we went to check the amps and found that one wasent getting any signal. As it was with one sub it handled the room just fine. with two

But yeah I guess my point is these things kick. Just give em plenty of power JBL recomends 1200-2400 watts.

 

[bill h]

I'd look at replacing the 255s with a pair of dual 18" speakers (JBL SR4719's). The 255s is only 300w RMS of power each, not much for sub work. The MP418s is 660 into 1 18 but the box design is too small. I'd look at 2x 4719s and 1 crown CE4000 (no ce2000's) for power. Even the RMX5050 will do nicely. I have a Carver PT2400 for sale too.

pete

Thanks for the info. Wish I would of talked to you before But you are right in it being the speaker. We hooked up a different speaker and it was night and day.