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Author Topic: Crossover Points- Less strain on amps, speakers , Suffering sound quality  (Read 16479 times)

Mark McFarlane

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Don't get hung up about cabinet designs. ...

Sky, I think you are missing the point. The same speaker in 4 different cabinets will have 4 completely different frequency and phase response curves.  Phase-vs-frequency is as important as frequency-vs-amplitude when you have more than one speaker driver.

Perhaps it would help if you think about a speaker like a car engine: the same engine in a go cart, a sedan, and a dump truck will not respond the same.  No one can tell you how to tune the engine without knowing the details about how it is deployed.
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Mark McFarlane

Sky Miller

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Unless I misread the manual, the XLS series only allows you to have either a hi-pass or a low-pass filter, but not both.
Like I said, I will be running my amps in bridge-mono, which can be setup as either highpass or low pass. I think you may have missed the part where I said I had three amps. (the fourth I am not going to count)

 This is not acceptable for anyone trying to do a three-way system with vented boxes (or any other boxes). You need a processor, even something as basic as a Driverack PA. Unless you can do this you will never achieve anything worthwhile with your set-up. Thanks for trying.

This has nothing to do with DIY cabinets (which could be great, or not), but simply the truth. IF you had a crossover/processor, I would suggest starting with crossover points at 90hz and 2k, but (as Ray said) there is no way to know what settings you really need. If you had more experience and knowledge you could make the adjustments by ear (trial and error), and you may still be able to do this, but not without a processor and the basic skills to set it up. A used DRPA can be found on eBay for under $200.
Thanks for answering my question about which crossover points you would choose. It would be helpful to know "why" you have chosen those two frequencies. I'm here to learn something; help me out here.
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-HammerSlammer

Tim McCulloch

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Well, you got out of answering another one! You came, you said absolutely nothing, then you left; typical.

So why be an asshole, Skylar?  This ain't Burger King and you're making demands of folks who VOLUNTEER to help others with live audio.  Loudspeaker system design is an entirely different thing, though, and if you want custom work done on your behalf there are several folks (on and off these forums) who we could suggest, but their hourly rates are not friendly for one-off builds.

You want free, accurate advice and you want it now.  I politely suggest that you take your quest to speakerplans.com and overlook the accuracy of most of the advice given there...  but there will be no shortage of folks with an instant answer.
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"If you're passing on your way, from Palm Springs to L.A., Give a wave to good ol' Dave, Say hello to progress and goodbye to the Moonlight Motor Inn." - Steve Spurgin, Moonlight Motor Inn

Jim McKeveny

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Sky-

Perhaps the Traveling Drum Soloist website would be more helpful?
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Sky Miller

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Not to sound evasive-but as others have said-there is no way of knowing without knowing more information about the cabinets.

Since you "designed" the cabinets-then you should know what the design specs are and whether or not you achieved those specs.
Yes. You are correct. But this is not about the "cabinets", its about choosing crossover points using the response curves of the "actual speakers" that I have provided links to.

Having some actual measurements (acoustical-not how big the cabinets are) would go a long way.
I could provide so much data that it would't fit in this forum. Then nobody would bother reading it. Look at what I did provide and work with that. We can always go into detail about everything else later on.

But unless detailed measurements are provided (including phase response) there is no way to give anything more than a guess as to the parameters needed.
There you go! I think you got it! I am looking for an "educated guess", based on the information given. Now that we got that out of the way, what is your educated guess, and why? Please don't forget to tell "why" you chose those crossover points.

The reason people are hesitant to give suggestions is that they simply don't have enough information to guess with.
Then I don't get it. You mean to tell me that if you were put in a bare room and given "only" the information that I provided, you couldn't come up with usable crossover points and an explanation as to why you chose them? OK; lets see how hard we can make this.

Think of it like this-you have asked a question like this.

"Me and some friends of mine are going to a festival in a 15 passenger van.  How much will it cost us to get in?"
How about this? You have a speaker that is capable of reproducing this set of frequencies well. You have another speaker that is able of reproducing these frequencies well. Oh look! These frequencies can be reproduced by both speakers well. What do I do? I don't want to put too much strain on one speaker unnecessarily, so I should split the frequencies so that some are dedicated to one speaker and the others are dedicated to the other. Gee; how do I determine where to split the frequencies up? I know. I'll look at the response curves and see how each speaker responds to a range of frequencies; that should help.

To me, that isn't asking a question without enough information.

Without knowing exactly how many people and what the cost of the tickets are-there is no way to guess.

We could "assume there are a total of 15 people-but there may be only 4 people or 20. 
OK. I give up. What critical data is missing here?
*You have speakers that are capable of reproducing these frequencies. You even have the data that tells you how well the speaker can reproduce a particular range of frequencies.
*You already know, or have a general idea of the range of frequencies to be pushed through the speakers (at least I hope you do)
*You have the capability to assign a set of frequencies to each speaker
*Sure, you know that the enclosures play a big part in what is heard, BUT that part is not given.
Now what are you going to do?

I know you want a simple answer-but to get a real answer you have to have some real tools to do the processing and real measurements to BEGIN to get some good starting points.
OK. What tools? What measurements? Why? If I had a question about tools, you would want to talk about frequency crossover points. God; I can't get past the mentality here.

Any answer somebody would give you have lots of other people saying they are wrong.  And EVERYBODY would be right-without more information.
Alright then. Just sit there and pout. Don't do anything. Don't contribute. Don't try to be a team player. You can be the guy that walks in the kitchen with his hands up in the air and starts shouting, "We don't have any sharp knives. We need bigger pans. We need a bigger sink. Oh my God, we can't cook anything in here!" In the meantime, there is a group of people in the corner making sandwiches for the hungry people.

Since you say you are going to adjust it to be right-then go ahead and do it.  And how do you determine what is "right"?
Enough said Mr Philosopher.
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-HammerSlammer

Sky Miller

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Hello everyone.
Notice how I started out so polite?
I am building a PA setup for a traveling drum soloist (me). I already have a few amps, some speakers, and I can't spend any more money. I want to get the highest dB level, and very best sound quality from the gear that I have now. Most of the concerts will be outdoors in the beginning, but there are also some dates planned in the future this year for some inside trade shows. My plans for the future (next year) will be to duplicate the same speaker array I have now, and add amps (more crown amps) to accomedate.

I'm not really sure I should be asking this question here, or not, but here goes:
I don't think I should have even come here. From the beginning I have been run over by trains on this site. Every time I was able to get up and walk away. I was forgiving enough to come back and try it again. Seems the train lurks in the darkness, waiting for me to return.

Just forget it! I get absolutely nothing at all when I come here, except agitation. A person can't have any kind of a meaningful discussion here. What you get is a bunch of guys trying to show-off and looking like a bunch of cry-babies. There is nothing at all that I want here. I don't want to be part of this kind of association.

At the present time, I have 6 speaker cabinets, each housing its own dedicated speaker, and another 2 enclosures, each housing its own horn. My typical setup is 3 stacked speakers on each side of the stage, with the horns up top, the subs on the bottom and the main woofers between.

I don't use a passive crossover; I use the built-in crossovers/filters in my Crown DriveCore XLS amps. My XLS 2500 is used for the subs in bridged mono mode, and the other two amps are DriveCore XLS 1000, which are also run in bridge mono mode. Each one dedicated toward pushing one of the woofers.

Now, I already know there are going to be people who are compelled to answer this post with the comment: "tune it to what you think sounds best."  My response to that is, "I will." My reason for posting this is to find out if I am thinking and going about this the right way. If I should be considering something else, I want to know. My settings are based upon what is on paper for now. I suppose I want to go through this in my head first and get some pro's opinions, to be sure I understand the concepts. So you will be looking at the same data I did when I came to my determination of settings.

So until I do my adjustments by ear, I want to hear, from professionals, what general setting they would start with in separating the frequencies, and why. I am exclusively using the Response Curves and other attached data for my choices below.

Speakers:
Here's what I have on each side:
The subs are Eminence Omega Pro 18A= 40Hz to 800Hz 800W RMS 8 ohms each
The Woofers are Eminence Kappa Pro 15A= 46Hz to 4K
500W RMS 8 ohms each
The HF drivers are Peavey RX22= 500Hz to 15KHz

These are my Settings:
Lowpass~3KHz for the Kappa Pro
Lowpass~630Hz for the Omega Pro
 For the RX22 and the Ampeg B2RE amp, I'll cut all frequencies down 12dB except 2K and above, I'll boost. Turn all knobs down (like mid-bass, etc) for the RX22 I hate this setup, but what else can I do except spend more money.

Amplifiers:
The (2) XLS 1000 bridged at 8ohms- 700 watts each
The XLS 2500 bridged at 4 ohms gives me 2400 watts
Don't laugh, but I'm a poor musician. This is all I have
To power the Peavey RX22 HF Compressors, I will be using an Ampeg B2RE amp and will be using the EQ and every other means incorporated in the unit to cut out the lows.

If anyone has other suggestions for me to consider, please feel free to make it known, but I would like to get my questions answered. I already know: sell the Ampeg and get another XLS 1000. (in the process)

*As far as using the DSP features of the DriveCore Series, I didn't find data about the dB curve at the lowpass and highpass filter settings, but am almost positive that whichever setting is choosen, it will not be an absolute drop-off, or will it be; anyone know?

I don't know what the protocol is here. I could just cut and create .jpg files of all the pertinent stuff and attach, or just provide links and keep myself out of trouble. I'd like to make it easier for readers, but legalities are considered. So you'll have to do some scrolling.

Specs for Omega Pro 18A
http://www.usspeaker.com/OmegaPro-18A-1.htm

Specs for Kappa Pro 15A
http://www.usspeaker.com/KappaPro-15A-1.htm

Specs for Peavey RX22 HF Driver
http://peavey.com/products/index.cfm/item/726/94835/RX%26trade%3B22HFDriver

Manual for XLS DriveCore Series Amps (click on Operation Manual) *pdf format
http://www.crownaudio.com/xls-drivecore.html

Cut sheet for Ampeg B2RE amp.
http://www.ampeg.com/products/b/b2re/
* The Users Guide can be downloaded as a .pdf at the bottom of the page
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-HammerSlammer

Bob Leonard

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If you want instant settings try 85hz for the sub, 1.6k for the mid.

I'll be sending a bill. could you reply with your address please.
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Ivan Beaver

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All I can say is " HELP US HELP YOU".

You are simply not providing enough information for us to be able to help.

You are looking for "simple answers", but quick simple answers provide WRONG answers.

If all you want to do is "make a lot of noise" then that is easy-but if you want it to be good-YOU have help.

For example-you said you say you "tuned" the cabinets-based on what?  Have you provided that information?

There are all sorts of different "tunings" that can be used-and will give different results for speakers-  Some people want extension-others want maximum output-other want a hump at the low corner-others want maximum power handling.

These are all different tunings-which did you use?  And why?

I know it sounds mean-but accurate answers need accurate data-simple as that.
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Ivan Beaver

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If you want instant settings try 85hz for the sub, 1.6k for the mid.

I'll be sending a bill. could you reply with your address please.
Bob-I disagree- I think 90Hz and 1.8K would be better---------------

Or maybe 80 and 1.2K or maybe 100 and 1.4K.

Any of those should "work" .
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A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Spenser Hamilton

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Step 1:




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