Distorted speakers...NEED MORE VOLUME!!! - AVS Forum
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post #1 of 32 Old 08-14-2012, 03:20 PM - Thread Starter
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Had an outdoor party last weekend in teh backyard and was very disappointed with the output from my system. At about -15db to -10db on the Harmon Kardon volume scale my Polk (main outdoor speakers and at least 2 of my "rock" speakers, started distorting to the point that I had to turn it down to between -15 - -20db. Not nearly enough to satisfy 30 drunken dancers!

Here's my setup, hopefully someone can advise as to whether I need more or less power or what?

Harmon Kardon AVR230 Receiver, 65watts/chnl
HTD MA-1235 12 Channel Amp, 35watts/chnl
2xPolk Atrium5 speakers 100watts, using 4 bridged chnls on the HTD amp delivering 100watts each in my understanding
4xoutdoor "rock" speakers 80watts, also using 4 bridged chnls on the HTD amp via a speaker selector switch.
All speakers run through impedance matching volume controls
I also have 2 "old school" BIG JBL loudspeakers inside, connected to the speaker A output on the Harmon Kardon. They are also on a vol. control but were turned all the way down as we didn't need the music on inside. I understand having them just turned down was probably draining some of my power, I perhaps should have disconnected them completely however that was power from the receiver and not the amp which isn't really related...is it?

We have one big party a year and it seems we always want it louder but this year seemed to be the first where the disortion was this bad. Maybe I'm just getting older and more sensitive to it but it was bad. I think it's the first time I had the amp channels bridged for a party but that should have given me more volume I thought. I think Polk are ok speakers so am I overdriving them or underpowering them? For the record I can drive the big JBL speakers on their own into the +db range before I get distortion so it seems the source is clean? Is my HTD amp crap?

Thanks in advance!
Paul
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post #2 of 32 Old 08-15-2012, 05:26 AM
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Quote:
Originally Posted by climberpm View Post

Had an outdoor party last weekend in teh backyard and was very disappointed with the output from my system. At about -15db to -10db on the Harmon Kardon volume scale my Polk (main outdoor speakers and at least 2 of my "rock" speakers, started distorting to the point that I had to turn it down to between -15 - -20db. Not nearly enough to satisfy 30 drunken dancers!
Here's my setup, hopefully someone can advise as to whether I need more or less power or what?
Harmon Kardon AVR230 Receiver, 65watts/chnl
HTD MA-1235 12 Channel Amp, 35watts/chnl
2xPolk Atrium5 speakers 100watts, using 4 bridged chnls on the HTD amp delivering 100watts each in my understanding
4xoutdoor "rock" speakers 80watts, also using 4 bridged chnls on the HTD amp via a speaker selector switch.
All speakers run through impedance matching volume controls
I also have 2 "old school" BIG JBL loudspeakers inside, connected to the speaker A output on the Harmon Kardon. They are also on a vol. control but were turned all the way down as we didn't need the music on inside. I understand having them just turned down was probably draining some of my power, I perhaps should have disconnected them completely however that was power from the receiver and not the amp which isn't really related...is it?
We have one big party a year and it seems we always want it louder but this year seemed to be the first where the disortion was this bad. Maybe I'm just getting older and more sensitive to it but it was bad. I think it's the first time I had the amp channels bridged for a party but that should have given me more volume I thought. I think Polk are ok speakers so am I overdriving them or underpowering them? For the record I can drive the big JBL speakers on their own into the +db range before I get distortion so it seems the source is clean? Is my HTD amp crap?
Thanks in advance!
Paul

Everybody blames the amps when there is distortion, when speakers have 10-100 times more distortion unless the amp is clipping badly.

I'd move the old-school JBLs to where the dancers are. You didn't say which JBLs they are, but I'm thinking something larger and more efficient.

Let's talk frankly about these Polk Atrium 5 speakers. I looked at their spec sheet and my intuition screams "BS!" Speakers this size (11 x 7 x 8) just don't have true 90 dB/W broadband sensitivity and 60 Hz (- 3dB) response.

Throwing power at speakers is a last-ditch effort. If you want loud dance music, first you get speakers with size, bass extension, and efficiency. Those three things always come together. If you sacrifice one of them, it takes the others away with it. Those are just the immutable laws of physics doing their job.

Here are some "small" speakers that I can throw a lot of power at and make work in your application:

http://www.electrovoice.com/product.php?id=250



They are 18" x 11" x 10". IOW the box volume is about 8 times that of the Atrium 5s. They are rated for about the same frequency range as the Atrium 5s, and twice the efficiency. BTW, I think they don't have the claimed bass extension, but with a lot of power and a good parametric equalizer I can take care of that. By lots of power, I mean 2 kilowatts (!!!! ;-) Yes, 2000 watts). BTW, their cost seems to be in the same range at the Atrium 5s. Do you see where I'm headed here?

It is all about having the right tool for the job...
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post #3 of 32 Old 08-15-2012, 06:28 AM
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While that may work for what was asked...The part that I am interested in, is the outdoor speakers part.

 

I throw at least one big party a year, this year will be the Vife's and I's 13th annual Wine Party!

 

My main speakers are 10" and can get plenty loud, however, I am looking for some outdoor speakers that can do a decent job.  I have eclectic music tastes, but during parties, it is mostly dance/pop/hits/rock. 

 

Like I said, inside, I've got everything covered, but outside, not.  The speakers linked above, don't seem to be weather resistant.  So like the OP, I need a set(maybe more) of weather proof/resistant speakers that can make a party jump outside, as well as inside.

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post #4 of 32 Old 08-15-2012, 06:45 AM
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Get some professional sound reinforcement speakers, if you want them outdoors playing loud. Then get one of 1000W/channel Behringer amps for them. You can't expect any decent sound outdoors from 60W amplifier like your HK.
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post #5 of 32 Old 08-15-2012, 07:34 AM
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Originally Posted by underminded999 View Post

While that may work for what was asked...The part that I am interested in, is the outdoor speakers part.

I throw at least one big party a year, this year will be the Vife's and I's 13th annual Wine Party!

My main speakers are 10" and can get plenty loud, however, I am looking for some outdoor speakers that can do a decent job.  I have eclectic music tastes, but during parties, it is mostly dance/pop/hits/rock. 

Like I said, inside, I've got everything covered, but outside, not.  The speakers linked above, don't seem to be weather resistant.  So like the OP, I need a set(maybe more) of weather proof/resistant speakers that can make a party jump outside, as well as inside.

Obviously, there's something wrong with ZX1s in your mind because you obviously did not follow up on them. They are weatherized. What's the problem?
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post #6 of 32 Old 08-15-2012, 08:33 AM
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Quote:
Originally Posted by arnyk View Post


Obviously, there's something wrong with ZX1s in your mind because you obviously did not follow up on them. They are weatherized. What's the problem?

I stand corrected. 

 

I have not found where the webpage provided states that it is weatherized.  However, since they do mention that the grills are stainless steel, I should have deduced that they are weather resistant.  I did look at the brochure's PDF, but still could not find where they state it is weather resistant.

 

Either way tho, I should have figured it out.

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post #7 of 32 Old 08-15-2012, 09:00 AM
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Quote:
Originally Posted by underminded999 View Post

I stand corrected. 

I have not found where the webpage provided states that it is weatherized.  However, since they do mention that the grills are stainless steel, I should have deduced that they are weather resistant.  I did look at the brochure's PDF, but still could not find where they state it is weather resistant.

Either way tho, I should have figured it out.

Sorry for not being more explicit in the OP.

BTW, for more money the larger ZX-5s have a weatherized version that is prett close to being waterproof (not just water resistant) They have an acoustically transparent diaphragm across the front and water tight sealing around the speaker cable which is designed to be wired into place. They also have, without equalization even better low frequency extension, efficiency and humongous dynamic range. The ZX series speakers are all very smooth sounding.
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post #8 of 32 Old 08-15-2012, 09:11 AM
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I used to be a mobile DJ and had occasion where I had to do a outdoor venue. Simply speaking, you need lots of amp power (250W+) and efficient (98db+) and large (18") bass drivers to do any good outdoors. No home stereo will do well in the bass dept in such circumstances.

As an example, me and my friend had a 225w (X2) amp running (2) CV 18" folded horns (102db efficiency) and it was what I would consider the MINIMUM for decent outdoor bass response.

Sorry, but 65w and 100w receivers driving 12" and or even 15" woofers rated at 88-92db efficiency arent going to do it.

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post #9 of 32 Old 08-16-2012, 12:59 PM
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From the ZX1 features list on the page Arny linked: "•Long-excursion weather-treated EV8L woofer". I did not see it explicitly saying it is weatherized, but the ZX line is designed for that (composite cabinets, some sealing/coating, etc.) Other companies also make similar products.

To fill even a fairly small outdoor area takes MUCH more power and drivers than in-room systems; the sound escapes to the great outdoors instead of being reflected back into the room, and there is no help from room modes or reflections. Add to that a bunch of people talking and alcohol, and figure you're going to need 2 - 4 x the number of speakers and another 10 - 20 dB in power/efficiency to sound loud. Back when I did outdoor venues, I had to use my "auditorium" rig that added an extra pair of large speaker systems and another 2 - 3 amplifiers (four monoblocks instead of two or a single stereo amp).

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post #10 of 32 Old 08-16-2012, 02:33 PM
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What r u using as a source? If using a phone, iPod, or computer make sure u have the volume turned down on the source and up on the amp can't tell ya how many problems have been solved by this

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post #11 of 32 Old 08-20-2012, 01:47 PM - Thread Starter
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Thanks for all the input!

I was out a a club Fri night and cornered the "sound guy" for a minute and asked for his opinion. He echoed what some of you are saying that 200+watts per side is needed.

Curious about the last post from yaomizzle where you mentioned keeping the volume down on the source. I do use itunes as my primary source running off my PC. I have the computer wired into Vid3. I always kept the volume in itunes pretty much max'd and the volume on the computer about 75%. I need some volume on the PC or I get no output, what levels do you recommend?

Anyone else familiar with the EV brand of speakers recommended? Being a newbie here I'm familiar with the more mainstream names only it seems!

Thanks again!
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post #12 of 32 Old 08-20-2012, 01:49 PM
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Try 75-85% on your source device and crank the amp if still distorted and uve already diagnosed they aren't faulty speakers u need more power

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post #13 of 32 Old 08-20-2012, 01:54 PM - Thread Starter
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Oh I forgot to add. I was chatting with the amp and speaker manfacturers as well. One of them suggested checking the inline volume controls. I'm going to start there as that's the cheapest place to start!
When I first got this system together I had all outside speakers running through a speaker selector, max 100watts, so I don't think I gave much thought to the volume controls. I knew enough that if I had only 100watts going into a switch that would be reduced by roughly half for each pair so I wasn't at all concerned about "needing" a 100watt volume control. I think I may have cheaped out there so I'm going to replace the vol on my outdoor mains and see what that does.

By what I'm reading here it seems unlikely that it will give me the desired end result but might cleanup what I have and buy me some time to invest in some more/better gear!
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post #14 of 32 Old 08-20-2012, 02:38 PM
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stadium pa horns would probably get it done...

- chris

 

my build thread - updated 8-20-12 - new seating installed and projector isolation solution

 

http://www.avsforum.com/t/1332917/ccotenj-finally-gets-a-projector

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post #15 of 32 Old 08-20-2012, 05:12 PM
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Originally Posted by ccotenj View Post

stadium pa horns would probably get it done...

Last few large stadiums I've been in used a distributed system composed of a large number of non-horn speakers, or speakers that used horns for the highs and cones for the lows.

The comment that Ev is not mainstream is pretty funny to old timers, since back in the day they were one of the three largest manufacturers of both home and professional speakers.

In the 80s, they cut back on their consumer presence but remained influential in pro audio.
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post #16 of 32 Old 08-21-2012, 11:41 AM
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EV not mainstream? Ha, that IS funny!

BTW, it's not as much about amp power, much more about speaker efficiency. Every doubling of amp power is a 3dB change. 200W to 400W = +3dB. 400 to 800 is another +3dB. Yet a perceived doubling in volume takes a 10dB change. You got to have efficient speakers to get loud sound at a distance, especially outdoors.
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post #17 of 32 Old 08-21-2012, 11:43 AM
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Quote:
Originally Posted by has7738 View Post

BTW, it's not as much about amp power, much more about speaker efficiency. Every doubling of amp power is a 3dB change. 200W to 400W = +3dB. 400 to 800 is another +3dB. Yet a perceived doubling in volume takes a 10dB change. You got to have efficient speakers to get loud sound at a distance, especially outdoors.

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post #18 of 32 Old 08-21-2012, 02:44 PM
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Originally Posted by has7738 View Post

EV not mainstream? Ha, that IS funny!
BTW, it's not as much about amp power, much more about speaker efficiency. Every doubling of amp power is a 3dB change. 200W to 400W = +3dB. 400 to 800 is another +3dB. Yet a perceived doubling in volume takes a 10dB change. You got to have efficient speakers to get loud sound at a distance, especially outdoors.

Problem is that additional speaker efficiency can only go so far.

Horn drivers pretty much run out of gas between 108 and 118 dB/W and cone speakers do the same between 100 and 110 dB/W. After that, you do what you can with amplifier power until the voice coils can't take any more thermally, and then you start using multiple speaker systems and multiple amplifiers.

The column-type speakers that are becoming common in large venues are formed of stacks of 2 and 3-way systems, each individual system in the stack with a killowatt or two of amplification backing it.

The speakers in the stack have controlled directiivity so that each may cover only a relatively small part of the seating area.
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post #19 of 32 Old 08-22-2012, 01:47 AM
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Quote:
Originally Posted by arnyk View Post

Problem is that additional speaker efficiency can only go so far.
Horn drivers pretty much run out of gas between 108 and 118 dB/W and cone speakers do the same between 100 and 110 dB/W. After that, you do what you can with amplifier power until the voice coils can't take any more thermally, and then you start using multiple speaker systems and multiple amplifiers.

Yup, all true. In the context of this tread, though, we're talking about consumer HIFI speakers not being loud enough for his out-door party. Consumer HIFI speaker's efficiency is often down around the high 70s, low 80s, sometimes hitting the high 80s, but that's about it. So, just by selecting a pro PA speaker that's up around the mid to upper 90s, you get the effect of 10-15dB more SPL with the same power amp. That's the same as taking your 100wpc AVR and making it over 1kWpc, which would of course transform his speakers from sound emitting devices to smoke emitting devices. Assuming the OP isn't going to invest in huge and expensive power amps and risk his speakers life span, high efficiency speakers, rented for the occasion, seem to be the solution to the volume issue. All major cities and many smaller ones have sound companies that rent PA speakers for very reasonable prices. Usually the entire weekend is considered 1 day. The might even come with nice tripod stands to get them up and overhead, letting the sound cover a larger area before being blocked by partying bodies.
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post #20 of 32 Old 09-05-2012, 11:26 AM - Thread Starter
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Thanks for all the comments!

OK so let's say I buy in and grab a couple EV's, they are spec'd at 200w continuous, how will they respond to the 100wpc I'm able to currently deliver? Will I need to add another amp to power those new mains?

Thanks again!!!
Paul
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post #21 of 32 Old 09-05-2012, 01:14 PM
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What problem do you anticipate running the speakers with power less than their max rated power?
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post #22 of 32 Old 09-05-2012, 01:45 PM - Thread Starter
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I guess my concern would be that I wouldn't get enough out of them to warrant the purchase? Still trying to wrap my head around all of this I'm really not sure what happens when you under power a set of speakers. The EVs are more sensitive but they're rated at 200-800watts, thats WAY more power than I have at this time so I don't know if I would be able to drive them sufficiently or not? There must be some minimum power needed to aquire that level of sensitivity?

Thanks again!!
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post #23 of 32 Old 09-05-2012, 01:51 PM - Thread Starter
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I'd be game to throw up to $1000 at this problem to get an acceptable solution. Just hoping to hedge my bet as carefully as possible to get the best "bang" for the bucks!

During the rest of the year the setup I have is absolutley fine, just those one or two parties I need to beef up for. Renting gear would be ok I guess, just rather not go through that hassle if I can get a good solution with a one time purchase.

Cheers!
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post #24 of 32 Old 09-05-2012, 02:46 PM
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Very likely the power rating for the EVs, like most to all commercial speakers, is a thermal rating - - how much power you can hit them with for an extended time without them melting. It is not likely an indication that the speakers will continue to respond linearly (getting 1 dB louder for each additional dB of input) at the extremes.

Doubling the power yields, assuming the speakers remain linear, a 3 dB increase. Most folks I've read describe that as "about one notch" louder. So from 100 watts to 200 watts may only get you more compression and distortion from the speakers, but if not, it'll get you one notch louder.

To know whether they are enough you need to know how much enough is for you. That is you need to know how loud you want the sound, and at what distance (outdoors, the SPL will drop 6 dB for each doubling of distance from the speaker).

How loud a speaker gets with a particular input is called sensitivity. Different speakers have different sensitivities (and the way manufacturers describe them in their specs also differs so you can't necessarily compare from spec to spec without knowing whether they're talking for example about only how loudly they'll play a 1000 Hz tone or a broader range (lower frequencies are harder to reproduce) or if they are 4 ohm speakers specified at the voltage that would give you one watt at 8 ohms (a common trick that "cheats" by 3 dB - - because at that voltage the 4 ohm speaker is going to draw 2 watts, not one). My general impression of EV is that they are straightforward about their specs, so at least whatever they publish will define the relevant paramaters. If the EVs were 100 dB for one watt at one meter, 100 watts would give you 120 dB peaks at one meter, 114 at 2 meters, 108 at 4 meters, 102 at 8 meters, 98 at 16 meters. Pretty dang loud. Typical conversation is described as being about 65 dB.

a secondary -ish issue for outdoor reproduction relates to directionality. In general, bass sounds are omnidirectional while midrange and higher sounds are pushed more likestraight out (say covering a 90 to 120 degree angle) from the speaker. That 6 dB per doubling loss is about sound spreading out. SInce the bass spreads out more than the treble, at some distance you'll start to feel the sound is bass shy, but I honestly could not tell you what that distance is . . .
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post #25 of 32 Old 09-05-2012, 03:16 PM
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Quote:
Originally Posted by climberpm View Post

Thanks for all the comments!
OK so let's say I buy in and grab a couple EV's, they are spec'd at 200w continuous, how will they respond to the 100wpc I'm able to currently deliver? Will I need to add another amp to power those new mains?

The key parameter that tells you how loud a speaker will go with a certain number of watts is called sensitivity, and given in dB/watt. 80-90 dB/W covers your typical home speakers. The ZX-5s are rated for 98 dB/watt which is quite high. Furthermore this is a conservative rating, unlike some other similar-appearing ratings.

Going from your higher-efficiency home speakers with say 88 dB/W sensitivity to speakers with 98 dB/W sensitivity is like making your power amps 10 times more powerful.

If the ZX-5s are a little salty for you, you may want to try the ZX-3s which are a tiny bit less sensitive and will cost you a few Hz of bass.
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post #26 of 32 Old 09-06-2012, 11:23 AM - Thread Starter
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Thanks ArnyK and Jhaz

Sorry if I'm a little slow on this but I do feel like I'm making progress, thanks to you guys! Must be frustrating for you pros/veterans, I appeciate your sticking with me on this!

So I get the sensitivity rating but I how do I know how much power I need? I'm pushing 100wpc and the zx-5s are rated at 200/800. I've seen some indications that a rule of thumb is to double th power at the amp to that of the speakers, sounds dangerous/expensive if the volume control were to get into the wrong hands!

Would I be safe to buy the zx-5s and try them on my existing setup and if they still weren't loud enough does it make sense to add a 400w amp (200w a side) for those speakers?

It seems like, and I think you mentioned before ArnyK, that you need a certain amount of power to make the bigger speakers work the way they should, how do I come up with that magic number?

Thanks again!!!!
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post #27 of 32 Old 09-06-2012, 11:43 AM
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Quote:
Originally Posted by climberpm View Post

Thanks ArnyK and Jhaz
So I get the sensitivity rating but I how do I know how much power I need? I'm pushing 100wpc and the zx-5s are rated at 200/800.

Power ratings of speakers are primarily guides to avoiding frying them.

Sensitivity ratings give you a guide to estimate how loud they will get with a certain amount of power.

100 watts is 20 dB greater than 1 watt.

If you have a 100 wpc amplifier, then a 99 dB/W speaker will make a sound of about 119 dB SPL at one meter on-axis in an anechoic chamber. This is very loud! Running outside is more like an anechoic chamber than inside. Depending on how high you position the speaker (ZX-5s are set up for a standard DJ/Live sound pole mount) and what the surface under them is like and how many reflective walls there are around you, the SPL will drop off at from 3 to 6 dB every time you double the distance. So, twelve feet away is aout two doublings or 1 meter for a maximum of 12 dB loss. At worst the SPL will drop to about 112 dB at 12 feet which is still very loud. Since there are two speakers, you might get 3 dB more than that or about 115 dB, which is even a little bit louder.
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Would I be safe to buy the zx-5s and try them on my existing setup and if they still weren't loud enough does it make sense to add a 400w amp (200w a side) for those speakers?

If you want appreciably more sound, you have to be a lot more ambitious than that! 100 watts -> 200 watts is just a change of 3 dB so that it sounds only a little louder. If you want to get sound that is twice as loud, then get a power amp that is 10 times more powerful. Interesting thing about that is that ZX-5s can probably handle a 1,000 watt amplifier used tastefully. I've used mine with power amps ranging from about 100 watts to over 500 watts. I've done live sound outside on the grass with a pair of them using 125 wpc power amps and it was just fine.
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post #28 of 32 Old 09-06-2012, 12:46 PM - Thread Starter
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Originally Posted by arnyk View Post

If you have a 100 wpc amplifier, then a 99 dB/W speaker will make a sound of about 119 dB SPL at one meter on-axis in an anechoic chamber. This is very loud! Running outside is more like an anechoic chamber than inside. Depending on how high you position the speaker (ZX-5s are set up for a standard DJ/Live sound pole mount) and what the surface under them is like and how many reflective walls there are around you, the SPL will drop off at from 3 to 6 dB every time you double the distance. So, twelve feet away is aout two doublings or 1 meter for a maximum of 12 dB loss. At worst the SPL will drop to about 112 dB at 12 feet which is still very loud. Since there are two speakers, you might get 3 dB more than that or about 115 dB, which is even a little bit louder.

Not trying to nit pick here just want to be sure I understand your math, I think you may have made a typo? Hopefully so because this is starting to make sense...I think!

So we start with 119dB SPL@1meter, we move out two doublings, loosing 3-6dB per doubling so we'll say we loose the max which would be 12dB. 119dB -12dB = 107dB@ 4meters. If we were conservative and used the 3dB per doubling we would end up with 113dB(119-6) @4meters. How did you get 112dB, was that just a typo?

Assuming a typo, I see that you can only do so much with sensitivity, from there, the power kicks in to make up the remaining difference in volume. I hope I'm right because I feel you've really lifted the cloud for me!!

Thanks ArnyK!!!
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post #29 of 32 Old 09-06-2012, 12:51 PM
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Originally Posted by climberpm View Post

Not trying to nit pick here just want to be sure I understand your math, I think you may have made a typo? Hopefully so because this is starting to make sense...I think!
So we start with 119dB SPL@1meter, we move out two doublings, loosing 3-6dB per doubling so we'll say we loose the max which would be 12dB. 119dB -12dB = 107dB@ 4meters. If we were conservative and used the 3dB per doubling we would end up with 113dB(119-6) @4meters. How did you get 112dB, was that just a typo?
Assuming a typo, I see that you can only do so much with sensitivity, from there, the power kicks in to make up the remaining difference in volume. I hope I'm right because I feel you've really lifted the cloud for me!!
Thanks ArnyK!!!

Yeah, typo. Calculating SPLs with this little bit of known information known is just an educated guess, so even my typo could be right! ;-)

I think you can now see how getting loud clean sound takes a mixture of efficient speakers and big amps, and why the way you tried to do it first pretty much had to fail.
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post #30 of 32 Old 09-06-2012, 03:08 PM
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I wonder whether it would be worthwhile for the OP to explore powered PA speakers. You eliminate the outboard amp, can get pretty decent sound (great sound if you want to spend the bucks) and Mackies, JBLs, QSCs, etc. will have power management that will prevent driver destruction as the party goes on. One thing about parties. They usually involve alcohol, and one of alcohol's known effects is to make things sound quieter. So you keep turning up as the night goes on until you are rewarded with silence . . . FWIW, I love my QSC K10 (used as a keyboard monitor) but a pair would exceed the budget, at least new. Great, transparent power management, Lets the piano sound sound like a piano . . .
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