Sub and Amplifier

[djtunes]

http://www.pssl.com/QSC-GX7-2-Channe...er-725W-8-Ohms

http://www.pssl.com/Peavey-PV-118-18in-400W-Subwoofer-

Or

http://www.pssl.com/B52-ACTPRO-18S-S...red-Subwoofer-

Pros & Cons:
Pros for the Passive set up is that you can get another matching sub down the road for another $290 to add more boom.
Cons for the passive set up is that (if you don't have, or buy an external electronic crossover) you'll be relying on the internal passive crossover that's built into the sub which leaves it sounding a little muddy.

Pros for the powered set up is that it's all in one powered which as said before results in a more efficient set up.
Cons the thing is 97lbs. Vs. 73 for the peavey + To add another matching sub it will be another $700.

I am 100% sure the B52 will sound better.

[djtunes]

As always, don't run your amp or mixer into clipping or the signal can damage the speaker.

[dmcclure]

http://www.pssl.com/QSC-GX7-2-Channe...er-725W-8-Ohms

http://www.pssl.com/Peavey-PV-118-18in-400W-Subwoofer-

Or

http://www.pssl.com/B52-ACTPRO-18S-S...red-Subwoofer-

Pros & Cons:
Pros for the Passive set up is that you can get another matching sub down the road for another $290 to add more boom.
Cons for the passive set up is that (if you don't have, or buy an external electronic crossover) you'll be relying on the internal passive crossover that's built into the sub which leaves it sounding a little muddy.

Pros for the powered set up is that it's all in one powered which as said before results in a more efficient set up.
Cons the thing is 97lbs. Vs. 73 for the peavey + To add another matching sub it will be another $700.

I am 100% sure the B52 will sound better.

How big of room or number of people would 1 - B52 ACTOPRO 18 S do ? Most my weddings are 150 people or less and not really huge venues. I think I did a wedding with 200 people once. I live in a pretty small market compared to a lot of people here , so most the stuff I do is small scale. Apparently I'm pretty good at not abusing equipment as I have never *knock on wood* damaged or destroyed any equipment. I have ran powered subs , passive subs with amps and pretty much any kind of situation. Past 2 weddings I have done were both outside it was 110 outside and I have no tent or protection from the sun. Yes , that is my fault for not demanding some shade but this also is why working for someone else sucks. The mixer was so hot from the sun I was almost burning my finger tips and I'm not joking one bit.

[Conanski]

How big of room or number of people would 1 - B52 ACTOPRO 18 S do ?

I rent out systems with 1 Mackie SRM1801 active sub and a pair of TH12a active mains for smaller venues with 100-150 capacity and more often than not I find the sub gain control turned down to minimum at the end of the night.. meaning it's more than plenty loud for these smaller rooms and moderate spl requirements. Some folks are a little nervous about the Mackie brand as of late but so far(knock on wood) I have't had any problems with my inventory so I wouldn't hesitate to suggest this sub as another potential candidate for you, it's light too at 73lbs and surprisingly easy to handle.

[Ken Heath]

How big a room they "can" fill with sound really depends on your personal tastes and what you believe to be "enough"... some people ain't happy till they have twenty 18" subs in a school cafeteria, while others find a single cabinet sufficient!



The B-52 ACTPRO series are rated very conservatively, I believe you'll be pleasantly surprised and very happy.

[Bob Dietrich]

I think I'm basically in agreement with your point ... but I think your example is incorrect. True the increase to reproduce the increased dynamic range will take more power ... but that's more "peak" power, not "average" power. The average power is essentially unchanged, hence the heat is essentially unchanged. If you don't have that extra peak power available you'll simple engage the amp's limiter which basically just reduces the dynamic range back down. Granted this probably won't "sound" as good as it could if you hadn't fired the limiter but thermally to the speaker is very close to the same thing. However limiting in the subs doesn't mess with the sound quality like it does in the top box.

The bigger danger to speakers (thermal) by using a bigger amp is the possibility to keep turning up the average power level. Peak power rarely causes much damage (assuming you are talking about thermal damage and not mechanical/excursion damage).

Quite right! With todays overly compressed music it is very easy to run those average levels up creating a lot of heat and potential failure. It was/is much easier with older music which I found to be recorded with far more dynamic range. That was the point I was trying to make that if you have an amp rated at double the speaker for that extra headroom, if not utilyzed correctly, it can easily damage the speaker and isn't as neccessary for todays music as much as it is/was for the older material or better recorded material of any age.

I find it unreal that with modern technology and the ability to have such a wide dynamic range for a more lifelike sound, the engineers and artists are seemingly only interested in mixing at the highest possible average level to get that "loud" sound from their disc. I have many older vinyl discs which while sonically inferior due to the inherent limitations of the media itself (analog recording tape and the actual vinyl) has far more dynamic range from average to peak levels than todays top music.

A speaker designer I know breaks it down pretty simply...music is simply "amplitude over time"...and how quick a speaker starts and stops along with the ability to reporduce a realistic dynamic range is what makes a good system so exciting since live music is quite dynamic to be sure...also, as a drummer, or former drummer a long time ago, I can really appreciate a good dynamic system.

[hippydog]

As stated above, this isn't bad information at all. I love lots of headroom to be sure, and I like a lot of headroom myself in my systems...but given the nature of todays music it isn't as much of an issue as many people will destroy their speakers with too much headroom. .

Can someone provide an actual definition of headroom?

To me, headroom is an amp rated at at the speakers program level with a little extra room (IE: if a speaker is 250 watts RMS, or 500 watts program, then a good matching amp is 500 watts rated..)
an amp rated below 500 watts has no head room, where as an amp rated 600 watts has a little bit of headroom..

matching a 1000 watt amp with a 250 watt program speaker (500 watt peak/max) gives you lots of "headroom" sure, but its also a mismatched system, and thus a moot arguement..

again.. my advice is to first have an amp that MATCHES your speaker system, but if you have a choice between an amp thats underpowered or overpowered (within reason!!) then choose the bigger one..
Why?
to save yourself money..
because we change equipment, but amps can last a long time..
and that little extra headroom can make that amp still usable even when you make drastic changes to your arsenal..

but thats my opinion.

[dboomer]

Headroom is any power available that is not used. And yes, therefore it's wasted by definition. But it's a little like life insurance in this aspect.

So having headroom available ensures that you will have some ability to have a decent dynamic range (the power necessary to reproduce peaks above the continuous average level).

So strictly speaking there's no need for any headroom above that necessary to produce the dynamics of your material. Of course knowing exactly how much that is is sometes difficult. So in the interest of the highest quality sound you want as much as you can get. Typically the highest quality live music might have 20 dB peaks while current recorded music rarely has 10dB and usually something closer to half of that.