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Hi-Pass Filter recommendation for sub

DraDra Posts: 3,844
Hi all,

I use Yorkville Elite SW800 subs (18\").
They are listed as (I think) 45 - 150 (+/-3 db).
Where should I set the HPF and which filter / slope should I use?
Is there a good way, without doing damage, to determine the mechanical limits of the speaker? In other words, if the speaker is -10 @ 40 hz is it BAD to boost 40 hz to +10 with PEQ and set the HPF at 40 hz.
I am interested in a specific answer to my oringinal question and any concept informaton that you wish to add.

Thaks,
DRA

Comments

  • GadgetGadget Posts: 4,915
    Yo, Dra...

    Guess who...chuckle.. Hey I'm not familiar with that model? the only \"800\" in the elite series are the LS800P, and LS808? If the low limit of the sub is 40 hz and you boost the 40 hz area and set a HPF of 40 hz you will get more 40 hz... but you risk damaging the woofer from over excursion.. Remember even if you use an 18 db BW filter its falling off but still ends up with WAY more sub 40 hz diong it this way and thusly more dangerous excrusion... I suffered that ignominy with my Labs and even though they WILL do 27 hz doesn't mean that they CAN do it for protracted periods. It actually did NOTHING to the voice coil but shredded the surround.. BIG chunks came out of them.. and they were done.. another thing that happens is that the cone tears away fron the voice coil... NEITHER of these things were covered by the manufacturer.. so I had to recone them...

    As for the method.. if its a direct radiating sub and you hear a clacking sound its the voice coil hitting the mechanical stop..you can also start to hear greater distortion.. BUT if its a Horn loaded sub.. you will hear NOTHING.. as in works one minute bug bucks the next...Some amps have a built in monitor that measures the signal impedance of the woofer and as the voice coil heats up the impedance changes and it lowers the output automatically. Crown has a power monitor circute in some of its amps that monitors the amps outputs and sends that info to your computer so you can have feedback as to the amps power output.

    With a rating like that the woofers are 3db down @ 45 hz.. its likely that the limit is the cabinet design AND the woofers limitations.. I'd set a BW [email protected] 45 hz IF I had enough power to properly power those speakers...thats 2-4 times the rated power of the speakers.. If the speaker is rated at 400 watts as my Labs are 1600 watts is not to much power for these drivers.. remember thats then GOOD clean power.. without distortion. If you are under powered I'd bump that up to 50 hz..

    Gadget
  • DraDra Posts: 3,844
    The SW800 is the pa or grandpa to the LS808, I think. It is the same compound resonator (quasi horn loaded) style cab. I'm using an AP3000 amp (475 cont @ 8 ohms) bridges to 1500 cont @ 8 & 2400 @ 4. I do have a pair available. Would you use 1 per cab? FYI, the raw speaker is 4 ohm, but the cab is rate as 8 ohm... something to do with loading.
  • DraDra Posts: 3,844
    Gadget?
    I have a slight problem. Set up a single stack to do some playing and measuring. I normally use a 475 w amp for my 800 w (PROG) subs and never clip. I changed to a CE2000 bridged (1350w). Using the wizards canned settings, I do get a noticable increase in volume. Hi-pass set at 46hz @ BW24. CD playing and sounds great but I get spuratic pops, like a pencil slapped against a paper plate. Twice was enough. The very same thing happened last time I tried a different amp bridged at 2400w. Is my hi-pass too low? The limiters by default were at +18. After backing off the channel volume a bit and lowering the threshhold till the limiter started activating, it was well below +10. Help!

    DRA
  • GadgetGadget Posts: 4,915
    Hmmm.. sounds like the voice coil is bottoming out against the mechanical stops...thats REALLY bad.. and if it is it's either a bad cabinet design the wrong speaker in the cab or a bad speaker.. is it new? sure doesn't sound like Yorkville...to me... I have 400 watt drivers and I am powering them with 2000 watts.. so as long as they are set properly. That doesn't seem like an overly low cross point...Let me think about it for a bit.. any other info you can offer?
    G
  • DraDra Posts: 3,844
    I duplicated the Elite 1215 proccessor settings as best I could. I don't have access to the 260 PEQ settings I ended up with, but this is the curve from the 1215 chart.
    +4 @ 48hz
    +3 @ 60hz
    +2 @ 50hz
    +1 @ 80hz
    Cross @ 100 LR /48

    The speakers were reconed less than 2 years ago. They had started farting a bit from cone softening. I think they were 10 -12 years old then. They have the original RCF recone kits with the flat wire upgrade voice coil.

    These cabs do have the circuit breaker.
  • MikeyMikey Posts: 82
    What Gadget said...

    Or, could be digital clipping. Is there any DSP in your signal chain that shows clip lights coming on? This is also a similar sound to A/D converters being overdriven.

    Mikey
  • DraDra Posts: 3,844
    Straight out an analog Peavey mixer to the 260. Even if clipping at the output stage of the mixer, should just be distortion, right or no?

    DRA
  • GadgetGadget Posts: 4,915
    As I said I have seen newer amps that react to distortion as if it was clipping... ANY distortion in the chain can cause limiting in those amps... so to answer your question NO don't think that it's just distortion.. I keep (by the way) about 12 - 16 db of headroom whenever possible so that the system doesn't have a chance of seeing distortion...My faders never go above 0db/vu My Driverack is likewise under driven for that exact reason... Not sure I can tell you whats going on...700 watts is what you've got for the lo mids (15\") thats not a lot...I have in excess of 1000 watts per 15\" driver...and its still not nominal...As have said many times before... too much power is never enough...I drive my 400 watt Labsub drivers with 2000 watts , or 1000 watts each driver... and thats only only marginal...

    Hey thanks Mikey ... for stepping in here.. guys Mikey is a real celebrity here... he is the BOMB in speaker/room interaction and tuning, who hobnobs with the bigwigs Like Robert Scovill.. do a web search if you must but trust me we are VERY privileged to have Mikey here.. He is also a luminary of the SMAART measurement system.. and an author of some of it's training modules...What he says is gospel, and I for one would like to thank him for taking his time to help us here... It's VERY valuable time after all...Mikey.. you rule...

    gadget

    Gadget
  • DraDra Posts: 3,844
    I'll do some more tests today. It's suppose to bump 80 today. (sorry Gadget). Since I'll be using pre-recorded cd's as my source, should I use the material (songs of choice are Peg & Home At Last, Steely Dan) or recorded pink noise to set the PFL level. Either way, recording levels come into play.
    If music is used, should I set the peaks to 0 or the typical to 0?

    Here is the set-up that I will re-try today.
    DJ mixer out to Peavey RQ mixer channel (stereo), channel fader to 0,
    assign PFL and adjust channel gain to PFL meters for (your suggestion here) and using (your suggestion here) as the source.
    Stereo mains fader to 0, Mono sum to 0, mono out to 260.

    If clipping, digital or analog, were the source of the popping, wouldn't it happen whether the the speaker was getting 500w or 1500w?

    Could it be that the approximate boost curve on the sub at 500w is fine but that boost is too much at the higher power causing to much excursion?

    I'll try lots of things this afternoon. I have a hunch that it may be the Peavey. Not neccessarily the board, but the gain structure on that channel. I will definately take it out of the loop and see what happens.

    DRA
  • GadgetGadget Posts: 4,915
    well... it does sound like over excrusion... Try some PEQ in the LF limiting40, 50hz set a limiter to prevent overshoot... use the RTA and see what in the LF area is causing the overexcrusion...

    Hey it was 55 and beautiful here... thats T shirt and shorts weather up here...

    Good music choice ... but for shear sonic brutality Crap,, er Rap will reveal where your problems are.

    Just make sure there isn't any distortion anywhere...
    G
  • DraDra Posts: 3,844
    55 is really nice anywhere as long as there is sun and little wind.

    ***If music is used, should I set the peaks to 0 or the typical (average) to 0?***

    As far as the limiter goes, the wizard set it to +18 and over shoot to 2, over easy / 4. I will definatetly turn off the PEQ for the sub and let er rip. (maybe I should say let er fly.)

    Thanks, for all the input.

    David
  • MikeyMikey Posts: 82
    It looks like Gadget is taking you through a good process.

    There is one thing that I wanted to ask: how long and what gauge speaker cable are you using?

    I've used CE2000s in dance clubs before and never had a problem getting them to work just fine. Although they are not my first choice for subs, they will work-even at high power outputs.

    What I'm wondering is if you are driving a load that the amp doesn't like.

    BTW, Gary is waaaay too kind. I've been around the block a few times, but I'm not THAT good. There's always something new to learn. Isn't that what makes this so much fun?

    Mikey
  • DraDra Posts: 3,844
    Well first off, from what I've read, you know your stuff. I smart person will always admit (or claim to anyways) to not know everything.
    I'm just glad there are 2 guys with your knowledge willing to help.

    Cabling is 12awg / 30 ft / Speakon each end.
    Cabinet is 8 ohm / single 18\" factory loaded with a RCF 4 ohm speaker. I contacted Yorkville and they confirm this and that the amp \"sees \" the 8 ohm cab. I wanted to make sure of this before I tried to double up on bridged amp. I chose not to any way because the amp loses damping as impedence goes from 8 to 4.

    David
  • MikeyMikey Posts: 82
    Okay. Have you tried shoving a weiner in the warp drive? :wink:
  • MikeyMikey Posts: 82
    Can you please report your limiter settings? Time constants, over-easy, scrambled, sunny side up, peak stop, levels, etc.

    I think you said you had the threshold moved from +18 down to +10; let's take a look at the rest.

    Also, Crown amps are rated at full output with a +4dBu input. Let's make sure you aren't overdriving the input of the amp.

    What city, State are you in?

    Mikey
  • DraDra Posts: 3,844
    Well, I'm feeling pretty good. All is well. Obviously the musicality of Steely Dan, with its subtlety and impact, was the culprit. When I set the channel gain on the mixer to cruise at 0 at the output meters, I failed to realize that later in the song as the music increased, so would the input signal. I thought it was strange at the time that the channel gain was full on but not clipping (obviously till later). Re-zeroed output to peak at 0 and followed up with cd pink noise and got pretty much the same gain setting. So instead of full on, its between 12 & 1 o'clock. I first turned off the PEQ's and brought it up to level. Then I backed off and turned on the PEQ's and brought the volume back up full. Sweet. There was some rattling that I thought was a caster. So I sqatted in front of the cab and grabbed the caster. Yep, that was it, and yep, 5 seconds was all I could take. Felt a little disorriented. That's a good thing, right. HA

    So that settles it. Clipping an input can and will sound really bad and really noticable.

    For now, I have the limiter set to +15, Over easy / 4, and overshoot = 2db, Att = 1.8, Hold = 10, Rel 64/sec. Peak - ON. Amp level at 63. This is the wizard setting for the CE2000 except the original thr = +18db.
    I did follow up with some (c)rap and everything held up fine.

    I'm in Attalla, Alabama half way between B'ham and Huntsville.

    Thanks, again for all the input. I would have figured it out eventually, but your and Gadget's input help me feel better about my coarse action.

    David
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