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Loudspeakers Choosing Speakers

Discussion in 'Sound, Music, and Intercom' started by lieperjp, Oct 23, 2008.

  1. lieperjp

    lieperjp Well-Known Member

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    Hello, again.

    Really simple question, I guess, but I was wondering how to choose the right speaker. I'm looking to convince the powers that be to purchase some new speakers.

    Currently, we are using two 300 watt EV Sx300 speakers(will check product number later) just aren't cutting it. Last night at a rehearsal, the sound guy had to have the vocals clipping for a band to be able to 1) hear the vocals period, and 2) be able to understand the vocals. It sounded pretty bad, too - the clipping was quite noticable. I would like to get some nice active speakers, but am wondering how to pick out the right ones. They would mostly be for talent show applications, but might have some theatrical use. Something like the Mackie SR1530z (active) looks good (a little too expensive), but is there a way to tell if this will be better?

    I would guess the answer would also be room-dependent, as well. The auditorium is 115' long; 50' wide; at front it is about 30' from floor to celing, and in back it is about 12' from floor to celing, concrete floors and wood paneled walls. It's not super important the sound quality in the back of the room is as good as the sound quality in the front of the room, as for most of the shows people don't sit in the back 10 rows anyway (or, at least, we discourage it.) I

    Price Range: $1000 for sure, probably somewhere between $1250 and $1750, maybe $2500 if I'm lucky.

    I have ordered a copy of Yamaha's sound reinforcement handbook, so I hope some answers will be in there. But it's not here yet.
     
    Last edited: Oct 23, 2008
  2. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    While this link: PA Speakers: Buying Guide, may be too rudimentary for you and, a pleasant surprise, below your budget, it does contain some useful information. Is your $1000-2500 per pair or per box? What amplifiers will you be using? What are the primary, and ancillary, uses of the room?
     
  3. avkid

    avkid Not a New User Fight Leukemia

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    The band apparently needs monitors.
     
  4. Eboy87

    Eboy87 Well-Known Member

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    Exactly what Derek and Phil said; is your budget per box, and are these being used as monitors or mains? If you like the sound of the EV's, they do make a powered version of the SX boxes, but I don't remember the wattages off the top of my head. The Mackies are ok, not great, but they'll get you through. If memory serves me correctly, the Mackie boxes you mentioned tend to thermal out quickly, so watch the cooling on them.
     
  5. lieperjp

    lieperjp Well-Known Member

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    $2000 for everything. (or thereabouts.)

    The speakers would just be for events- it would not be a permanent install. The events mainly would consist of talent shows - where the acts are usually light rock bands with minor variation(1,2 or 3 electric guitar, bass, drum 1-2 vocal and 1-3 backup singers), drums not mic'd. They would probably also be used for theatrical shows - mainly just vocal back up for musicals. They would be the main speakers.

    The band did have monitors. The blame might lie with the sound mixer, who has the attitude "There's nothing else to do." But yes, last year we blew an amp and I wouldn't doubt that some point this year we will blow an amp or speaker.
     
    Last edited: Oct 23, 2008
  6. lieperjp

    lieperjp Well-Known Member

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    Then would I be better off getting passive speakers and the appropriate amp? I'm not totally dedicated to the active speaker, it's just that I think in our situation the active speaker might be easier for setup/takedown, especially because there is an outlet 3 feet away from where they would be set up.
     
  7. museav

    museav CBMod CB Mods Departed Member

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    I agree that it does sound like they may be wanting dedicated monitors rather than trying to get the house system to serve that purpose. But if you really do want new house speakers then there are a number of questions to help define what performance may be appropriate. What type of music and do you have a feel for the desired levels? Are the same speakers used for announcements where intelligibility is important? Are the speakers going to be permanently installed or portable? Will the speakers be flown (which it sounds like may technically be preferable) or on stands or ground stacked? This latter is definitely relevant to the Mackie SR1530z you referenced since per Mackie they are not to be flown or mounted on poles, only ground stacked.

    If you want active/powered speakers, is the needed power in the correct locations? Would you have to pull new cable for them? Would they be in a location where they won't easily be turned off accidentally but can be turned off when desired?
     
  8. BillESC

    BillESC Well-Known Member Premium Member

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    EV's ZX5-60 would be the passive recommendation from me. Double the wattage of the Sx300 and a 60 x 60 degree dispersion pattern for your long throw. You'll want to match it with an appropiate amp capable at least 1200w per side for peaks.

    For a little over your budget, EV's ZXA5 active cabinets offer 1250w bi-amped in a 60 degree model and they only weigh 50.5 pounds each. We did a side by side with Mackie's SA1521 and the EV cabs walked all over the Mackies.
     
  9. lieperjp

    lieperjp Well-Known Member

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    Thanks, Bill.

    Just want to say that they are not going to be used as monitor speakers. We have enough monitor equipment. They will be the main speakers. Our auditorium system was designed for lectures, not loud bands. Even when running audio through it for movies it sounds awful. We set up a system for the three/four talent shows each year and for each theatrical production. For the theatrical production, the EV's do work well as we don't have to drive much through them. But for the talent show type events they do not work well. First off, they are not powerful enough, and second of all not enough low end. Yes, yes, I know a permanent solution would be better, but the auditorium is scheduled for a full overhaul within the next seven years, and a new system will be implemented then. We were originally going to try getting some subs this year, but when I pointed out that we're clipping just to drive vocals enough, we started to look at this.
     
  10. lieperjp

    lieperjp Well-Known Member

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    That leads to another question (for clarification.) When matching an amp to speakers, the peak wattage of the speaker should equal the wattage of the amp? And then, if each speaker has a peak of 1200 watts, could one 2400 watt amp work instead of two 1200 amps?
     
  11. DaveySimps

    DaveySimps CBMod CB Mods Premium Member

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    As a rule you want your amps to be 1.8 to 2x the watts of your speakers RMS rating. If you are using active speaker, of course, they have already matched the amp for you.

    ~Dave
     
  12. museav

    museav CBMod CB Mods Departed Member

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    Okay, getting off topic, but let's look at the basis for this. First, although commonly used by many people including some manufacturers, there is actually no such thing as "RMS power". What is really being referenced is the continuous power based on RMS voltage and current but even that is not always the same thing from one manufacturer to another as the time periods and test signals used can differ.

    Second, this recommendation is based on touring or rental systems that may be used in a number of different venues and environments and for a wide variety of applications, so it is trying to balance having the greatest output possible available, and thus being able to work for the largest variety of venues and applications, with reliability and durability. But when you are selecting amps for a known application and fixed environment, as is typical with most installed systems, the process is quite different and is based on defining the desired results in the room, adding the desired headroom and backing into the power required for the particular speaker.

    So going back to the original topic of how to select speakers, you can pick a speaker and amp and assess what performance is possible or you can identify a desired result and then use that to determine the speaker and amp requirements necessary. One approach is defined equipment and variable results, the other is defined results and variable equipment. Neither is right or wrong but they typically are applied to different situations.
     
  13. mbenonis

    mbenonis Wireless Guy Administrator

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    Let's stop right there. :) If things were clipping, than he was overdriving the amplifier (or some gain stage before it). So I'd be curious to know what amplifier(s) was(were) powering the Sx300's? Depending on the answer, you might find that an amplifier upgrade is what you really need, and not new speakers.
     
  14. waynehoskins

    waynehoskins Active Member

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    Though new speakers might not hurt. :)

    Yes, if you're clipping, that's the the loudspeaker not being able to keep up, that's either poor gain structure or insufficient power (which is making you make something clip, being poor gain structure, to try to compensate).

    What are the power amps in this case, and what processing is in-between console and amplifiers?
     
  15. lieperjp

    lieperjp Well-Known Member

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    We are using a Crown amp, I will find out the type. I didn't see the clip lights on the amp coming on, but then again, I didn't look at the amp until the last ten seconds of the song when it was winding down. I will be sure to check that out tonight at the actual talent show.
     
  16. waynehoskins

    waynehoskins Active Member

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    Clipping can happen anywhere from the mic pre to the input on the amplifier. It's very likely to happen in a DSP that's set to provide a very low output level for 0 dB input. In that case, you're clipping the A/D in the front end of the DSP, but it's not letting you make it any louder on its output, so you push it harder with the same result. Not that I've ever run into that problem .. oh wait. :)
     
  17. lieperjp

    lieperjp Well-Known Member

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    Ok, so the mains are being driven by a TOA 1000 series P1060D amp.

    We are using a Crown XLS602 for monitors. Just thought I'd throw that in there. Just from an initial look at the specs for both amps it seems like this is the better choice for the mains.

    Also, for processing - the mics go straight to the board, then directly to the amp. No processing at all. Now that I think about it, could that be a source of the problem? Perhaps inserting a compressor or a driverack would help? (not to mention being a lot cheaper!)

    Note: The clipping was constant, not just when the input spiked.
     
    Last edited: Oct 24, 2008
  18. jkowtko

    jkowtko Active Member

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    Can you confirm where the system is NOT clipping? That sounds like an important piece of info to share since everyone is guessing right now.

    If you can AFL (solo) the outputs from the board on your headphones and they sound clean, then for sure it's the DSP/amp/speaker combination.

    If, however you can hear the clipping on your headphones at the AFL, then solo the input channel and see how that sounds. If it's not the speakers then you should be able to narrow down where in the mix you have the problem.
     
  19. avkid

    avkid Not a New User Fight Leukemia

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    SX300's are most certainly not happy with 200 watts.

    The Crown XLS 602 is also not enough for these boxes.
    An XLS 802 would be the ticket.
     
  20. lieperjp

    lieperjp Well-Known Member

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    While I cannot say for certain that the amps were clipping, I can say for certain that the mics were clipping at the board.

    Perhaps I am thinking of the wrong solution for the problem we are having. The problem is that to get everything - guitars, bass, piano, various percussion instruments, etc. to come out clearly and properly throughout the entire auditorium, they have to be loud. Not overly loud, but loud nonetheless. However, when vocals are added on top of all the instruments, to get the vocals to come through at a loud and clear enough level, both the gain and the volume levels have to be set through the roof. Which then backfires on us because the vocals come in with the scratchy clipped sound. This usually does not happen when it's only one guitar and a vocalist, but it tends to happen more and more as instruments are added.

    What we need to be able to do is get the instruments at a level where they can be heard and understood and still be able to have the vocals punch through where they too can be heard and understood. I had assumed that giving the speakers more power would give us more headroom to let the vocals come through. Correct me if I'm wrong.

    Now, I'm not mixing this event, but I have mixed events with the same equipment in the same setting. I (or any other mixer) get the levels to where they ideally should be, but it's too quiet, not only in the back but even towards the middle and the front. What is the logical next step for a beginner sound designer like me or the others I work with? Make it louder. So then the vocals (especially the vocals) start to clip. I say vocals because it seems that it's the vocals that clip most of the time - but every once in a while the guitar feeds clip as well.

    This is what makes sense to me, but I would be more than willing to admit I'm wrong. For all I know, it could be a simple mixing error. It could also be gain structure. I honestly have never heard of gain structure before, but after reading through a bunch of threads here I understand how important it is. I think I understand how to set the gain structure on the board, but not how to set the gain structure of the system.

    Edit: After reading [USER]AVKid[/USER]'s response, it might be a good idea to get the right kind of amp and also set the right gain structure before spending anything else.
     

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