Members BBJones Posted November 23, 2003 Members Share Posted November 23, 2003 I have read about 200 posts here that have helped, but I still have many questions. A little background... I'm a drummer I don't know much about proper PA/amp setups so please forgive my ignorance. I have a triggered kick drum and am trying to put together a system for 2 applications: - Jamming (5 person metal band) - small venue (100+ kids like in a small gym, 50'x50' maybe tops) Here is what I have so far: - DDRUM kick trigger into a MidiKat midi controller into an EMU PROCUSSION sound module - drum module into an Alto 12 channel mixer - mixer into an amp (no amp, but renting a AP800 right now) - amp into 2 x Peavey Black Widow 1801 18" speakers in home made cabinets Now on to my millions of questions (I could probably start about 10 different threads but I'll just keep it all here for now ) Speakers - am I safe to assume I have good speakers to get the job done? 350 w continuous with a 700 w peak seems like it should be enough to give me some massive kicks in small rooms right? - the guy I bought them from said the cabinets are "port tuned" to 100mhz. The cabinets are approx 2' wide, 2' deep and 2-1/2' high. The speakers are mounted facing down and there are 2 large port holes in the bottom section of the cabinet (I'm assuming to force the speaker output down then out the holes). The holes are about 8" in diameter spaced evenly on the front of the cab. - There is a small coil or something between the input jack on the back of the speaker cabinet and the connection to the speaker. Could this be some type of built in filter or crossover? (Again I have no clue) Amp - ok way too many choices for me since I really don't know what is going to be appropriate for this setup. I have been using the AP800 bridged into a single speaker cab and have NOT been satisfied with the volume I get before massive clipping. More on this below... - Since the speakers are 350w continuous @ 8 ohms, I assuming I should have at least 400w continuous into 8 ohms? Or more if I can afford it for more headroom... I may even just continue to run one speaker if I can only afford to power one for now. But with the right setup that should be plenty wouldn't it? - There are some cheapo's out there, Behringer, Alto etc (2400w@2h ohms for arund $650CDN) - But seriously, the AP800 *should* be 400w @ 8 ohms bridged which *should* be plenty for me to run one speaker right? Here is exatly how I have it setup right now (and am NOT at all satisfied) - DDRUM trigger on a single kick into my MidiKat midi controller into my EMU PROCUSSION sound module - 1/4 inch guitar patch cord into channel 1 on my Alto 12 channel mixer. Roll off high + mid freq (my version of a crossover ) - 1/4 guiatar patch into channel A on the AP800 - Bridge the AP800 (all set up properly) and use proper speaker patch into the speaker cabinet. More questions: - with the above setup, I get barely any sound without starting to clip the amp and mixer strip. As soon as I start to clip, there is a noticeable increase in volume. I've read that clipping is ok for a kick drum but I need something that can handle steady double bass (16th notes at 200-250bpm) without blowing anything up. - I put the mixer in the setup becuase before I plugged the mono out from the drum sound module directly into the power amp. Oddly enough, I got more "oomph" than I do with the mixer, however the mixer seems to give me a better range of frequency. - The mixer says that it will start to peak at 6db below the point that clipping will start so I'm assuming I can get away with constant kick drum peak on my mixer, but I don't know much about the AP800 (and I doubt I will buy it since there are better amps for a better price out there i.e. Crown) Sorry for the absurdly long post but I really wanted to try and get across what I have and what I need. Is this a simple matter of "buy a crossover you moron" or "buy a compressor" or something? Or am I just being paranoid about NOT running anything that shows a peak or clip signal? Any and all help is greatly appreciated! Thanks! Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 2 more things I forgot.... Can I just bypass the coil thingys between the speaker input and speaker connection to leave all the EQ'ing to my crappy mixer? A little more about them... The speaker input goes into what looks like a and I am trying to buy pieces that may end up becoming part of a bigger PA, so yes I may be going overkill in some areas but this setup won't be just a kick drum monitor for ever. thanks! EDIT: Oh yeah, any problem with putting casters on one of my 18" sub cabinets? They aren't stupid heavy but wheels would be nice. If subs should always sit flat on the floor I could always put the casters on the side perhaps? Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 Well great... read a little more and learn just enough to become even more dangerous... I read that "power amp class description" post and the one thing that really jumped out was that it mentioned that class D amps are probably the best suited for subwoofer applications. I've checked around on some of the amps I was looking at and can't see any of them mention what class of amp they are. Is this something most people don't care about? Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Whoa dude, lots of questions here! Originally posted by BBJones - Jamming (5 person metal band)- small venue (100+ kids like in a small gym, 50'x50' maybe tops)2 x Peavey Black Widow 1801 18" speakers in home made cabinets- am I safe to assume I have good speakers to get the job done? 350 w continuous with a 700 w peak seems like it should be enough to give me some massive kicks in small rooms right? Wrong, it MIGHT be barely adequate if you keep the rest of the band down. Sounds like they are bandpass cabs - if so yur screwed to get anything decent out of them without top boxes - and in any case if tuned to 100HZ that's way too high. If these are 4ohm speakers they'd be good on a QSC RMX1450 in stereo, if 8ohm bridged on that amp would cook them sooner or later so go with a RMX850 bridged. Ditch the internal coils. Link to comment Share on other sites More sharing options...
Members abzurd Posted November 23, 2003 Members Share Posted November 23, 2003 Subs tuned to 100Hz? - I'm no expert, but that doesn't make sense to me. Are you sure he didn't mean the will go to 100Hz? That "coil thing", as you describre it, is probably blocking the >100Hz frequencies. 700 Peak means the 350 is the Program rating and they are probably 175W RMS. If this is the case, these aren't all that powerful. If the design is poor then you may just have inefficient, low power, subs. As for the type of power amp. Don't sweat it. Sure, everyone has their opinions on what class amp is best for subs, but this is the least of your worries. right now. If I understand what you are saying you have been bridging an AP800 into 1 cabinet. From what I read about this amp you are putting 800W into this cabinet. You say you aren't getting much volume out of it. You should have blown those subs sky high by now so you have other problems. Looks like 250W is all you're gonna get out of this amp without overpowering (bridging). For you this is a good thing as you aren't really ready to be matching subs with Program power. It's too late now of course, but if you don't understand a lot about the subject, buying someone's home made cabinets probably isn't the best idea. They may be great, but then again they may be expensive doorstops. Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 Yes lots of questions these are 8ohm speakers. Here are the specs: PEAVEY MODEL 1801-8BW Nominal Basket Diameter 18" / 457.2mm Impedance 8 Ohms Sensitivity (SPL) 97dB Frequency Range 35Hz-1.0kHz Continuous Power (EIA RS-426A) 350 Watts Program Power 700 Watts Voice Coil Diameter 4" / 99mm Mounting Information Overall Diameter 18.1875" / 462mm Bolt Circle Diameter 17.375" / 441.3mm Baffle Cutout Diameter 16.75" / 425.5mm Overall Depth 5.53" / 140.5mm Overall Weight 18lbs. Thiele-Small Parameters Resonant Frequency (fs) 40.4 Hz Impedance (Re) 6.23 ohms Coil Inductance (Le) .30 Electromagnetic Q (Qes) .577 Mechanical Q (Qms) 5.59 Total Q (Qts) .523 Compliance Equivalent Vol. (Vas) 284.9 Liters/10.06cu. ft. BL Product(BL) 18T-M Voice Coil Overhang (Xmax) 5.0mm Surface Area Of Cone(Sd) .1237m2 I am running these ONLY for kickdrums. Only a single kick drum signal is going in to these speaker(s) at the moment. I would only start running more inputs if I got more cabinets (mid and high). This a bass/subwoofer application only. Why would the AP800 bridged cook them? The specs on that amp say 800w @ 4/8 ohms bridged. I would never crank everything up and would just like to get some volume while maintaining some headroom in the amp. Neither of which I'm getting now. I was expecting some type of "get a crossover" reply. Is this something I should try to match up properly depending on what amp I end up with or will any "decent" crossover do? Again, I am basically trying to build a full PA but am only starting with the subwoofer portion which I want to use now for kick drum amplification for jams and small rooms (where everything else is just stage volume). Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 By the way, when I went to test the speaker cabs before purchasing, I brought out a Fender 300C bass amp (300w @ 4 ohms) and set the limiter to "ON" on the bass amp head. Once the signal dropped below the clip limiter thingy on the bass head, the speakers put out a massive and huge bass sound. Something I can't seem to get with my kick drum. It's looking like my entire kick drum signal is all in the clip range and it all gets cut out (since I haven't run the setup with the amp clipping on every kick hit). But when the amp started clipping was when I started to get serious air moving kick drum sound. I'm just scared to run it when the little red light flashes on every hit Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones These are 8ohm speakers. Here are the specs:PEAVEY MODEL 1801-8BW Are you positive they aren't the 1801-4 model? Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones I was expecting some type of "get a crossover" reply. You only need a crossover if you are running top boxes. In fact, ditching the crossover coils will give you alot more "slap" to the kick. I have a front mounted 1801-4 in a bass cab that has suprisingly good high-end! Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 Originally posted by Roadkill Are you positive they aren't the 1801-4 model? Not positive but pretty sure from the pictures I've seen on the net. The tag by the speaker connection just says "1801". They look like a silver cast speaker frame. The pictures I've seen for the 1801-4's are black. Any other way to tell? There is a serial number tag on one speaker but it's damn hard to read becuase of the way the speaker is mounted... Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones It's looking like my entire kick drum signal is all in the clip range and it all gets cut out (since I haven't run the setup with the amp clipping on every kick hit). But when the amp started clipping was when I started to get serious air moving kick drum sound. The clipping puts back in some of the highend the coils kill - loose the coils! With 800w bridged into the cabs it is OK to flash the clip lights as hard as you want if you are ONLY running kick. Kick has a very low rms to peak ratio. Oh, and run both speakers even if it does lower the power per cab a bit - you'll make it up on moving cone area! Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones Any other way to tell? I don't remember there being color difference? Anyways get a cheap ohmmeter and measure them - you'll need one for other stuff anyways... Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 That is what i was also hoping to hear, that clipping the mixer and amp for kick signal was ok How much clip should I be comfortable with? No more than when it just starts to clip or push it up until I maybe start to distort the speaker sound then back it off to a safe distance? I really haven't pushed this system at all yet for fear of blowing something up... Assuming the speakers are 350w continuous, how about an amp recomendation? There is a used Crown CE2000 near me for around $800 CDN (400w/channel @ 8ohm). Or do I cheap out with a Behringer Euro2500 or Alto Macro and save a couple hundred bucks? Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 Originally posted by Roadkill I don't remember there being color difference? Anyways get a cheap ohmmeter and measure them - you'll need one for other stuff anyways... Oh. The only real difference is the resistance? Both speakers have 8ohms written on the tag so they must be the 1801-8's. I will test just for fun though Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 What gauge/type wire should I be using for bypassing those coils? I will be going direct from the 1/4 input jack to the speaker terminals and they will be about 10 inches long. Should I consider wiring up for parellel patching the speakers? One input from the amp (bridged) and run out of one cab to the other? Or just stick with running the speakers on a separate channels from the amp? Thanks yet again Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 23, 2003 Members Share Posted November 23, 2003 Sure sounds like you got yourself a whole handful of problems. Bandpass cabinets are efficient only over a narrow band of frequencies (duh, based on their name) and horribly inefficient over the remaining spectrum... so at the least, you have the wrong type of cabinet for application (without tops especially). The clip lighgts coming on without much volume indicate a possible problem with the amp not being able to deliver adequate current to the load. Is this by chance with both cabinets connected. I doubt that your amp is rated to bridge into a 4 ohm load. The colis are there to roll off the high frequency material from the woofers. They may also be doing a secondary duty of insuring that the cabinet's nominal impedance does not drop too low outside the design passband of the box. It depends on the design of the box and possible shortcuts the designer may have taken to make the design work. Link to comment Share on other sites More sharing options...
Members BBJones Posted November 23, 2003 Author Members Share Posted November 23, 2003 I'm currently running into one 8 ohm cabinet with the AP8000 bridged. If I get enough power, I may run both cabinets. Again, when I ran the bass head into a single cab when I tested them the bass was HUGE! I'm talking ground shaking-feel it in your chest-type bass... Are you labelling the cabinets "bandpass" becuase of how they seem to be built? Wouldn't that make them good for subwoofer range? Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones What gauge/type wire should I be using for bypassing those coils? I will be going direct from the 1/4 input jack to the speaker terminals and they will be about 10 inches long. 16 gauge is fine. Should I consider wiring up for parellel patching the speakers? One input from the amp (bridged) and run out of one cab to the other? Or just stick with running the speakers on a separate channels from the amp? Thanks yet again If you are going to bridge into both speakers run a separate cord from the amp to each. Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 23, 2003 Members Share Posted November 23, 2003 Originally posted by BBJones Assuming the speakers are 350w continuous, how about an amp recomendation? There is a used Crown CE2000 near me for around $800 CDN (400w/channel @ 8ohm). Or do I cheap out with a Behringer Euro2500 or Alto Macro and save a couple hundred bucks? Re-read my first message, where I covered that. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted November 24, 2003 Members Share Posted November 24, 2003 Originally posted by Roadkill You only need a crossover if you are running top boxes. In fact, ditching the crossover coils will give you alot more "slap" to the kick. I have a front mounted 1801-4 in a bass cab that has suprisingly good high-end! But not in a band-pass box. It essentially kills anything over 150-200 hz because all your sound is coming out of the vents. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted November 24, 2003 Members Share Posted November 24, 2003 Originally posted by BBJones Not positive but pretty sure from the pictures I've seen on the net. The tag by the speaker connection just says "1801". They look like a silver cast speaker frame. The pictures I've seen for the 1801-4's are black. Any other way to tell? There is a serial number tag on one speaker but it's damn hard to read becuase of the way the speaker is mounted... The only difference should be the impedence. One is 8 ohms and the other is 4. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted November 24, 2003 Members Share Posted November 24, 2003 Originally posted by BBJones I'm currently running into one 8 ohm cabinet with the AP8000 bridged. If I get enough power, I may run both cabinets.Again, when I ran the bass head into a single cab when I tested them the bass was HUGE! I'm talking ground shaking-feel it in your chest-type bass...Are you labelling the cabinets "bandpass" becuase of how they seem to be built? Wouldn't that make them good for subwoofer range? I'm not familiar with that amp. Who makes it? As for the cabs,the way you described them indicates that they are band-pass boxes. A well designed band-pass box is ok for subs. What you don't realize is that a kick drum has more than just super-low frequencies. But if you aren't feeling it,you are obviously missing the 50-80hz frequencies. I'd find a stereo amp that puts out about 400 watts rms/channel @8 ohms and then run it in stereo. BTW,a pair of 18"s in simple band-pass boxes are not going to push tons of air. Should be enough for really small rooms,though. Link to comment Share on other sites More sharing options...
Members abzurd Posted November 24, 2003 Members Share Posted November 24, 2003 It's a Yorkville amp. Get's it's max power at 4 ohms, but can be run to 2 ohms. Puts out 800W at 8 ohms bridged. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 24, 2003 Members Share Posted November 24, 2003 Originally posted by tlbonehead But not in a band-pass box. It essentially kills anything over 150-200 hz because all your sound is coming out of the vents. Correct... Roadkill is missing the point here. The whole point of a bandpass box is that is exhibits terrible parameters (efficiency, frequency response, distortion, damping etc) outside of the design passband. Link to comment Share on other sites More sharing options...
Members Roadkill Posted November 24, 2003 Members Share Posted November 24, 2003 Originally posted by agedhorse Correct... Roadkill is missing the point here. The whole point of a bandpass box is that is exhibits terrible parameters (efficiency, frequency response, distortion, damping etc) outside of the design passband. Huh? I said he was screwed getting a good kick sound out of it without a top box if it was a bandpass. What part of that do you disagree with? Link to comment Share on other sites More sharing options...
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