power amp questions [message #2312] |
Mon, 06 January 2003 09:10 |
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I know its a matter of perception..but I'm really struggling here... many of you know I run my small band PA consisting of a pair of 3x15 sirens for my mains, and a pair of 2x15 bass cabs for my subs. the siren cabs have the original heavey Jensons in them and they are not the issue..its my bass cabs.. I have them loaded with eminence 150 watt rms each drivers and I like the tone...in the past, as a matter of budget I've powered these cabs with original kustom 400 amps throwing 100wattsrms per side at the 4 ohms. I've been impressed with the amount of punch I get from those amps...I've tried rigs like PV power rated at over twice the rms and the result was a mushier bottom...the kustoms just seemed tighter...I borrowed a new Macike 1400 power amp for this past weekend..and yeah...there is a diff hitting those cabs with 450rms per side in terms of volume and a bit more chest thump..but I swear I was expecting significant difference...and it really wasn't there.. I'm guessing its more about my speakers and the cabs... I was shoulder to shoulder with a DJ system running a pair of PV black wido loaded 2x15 cabs..he was hitting them with a PV2000 amp and he could go places I can't...that's ok cause I really don't need that kind of sound pressure...but I swear, I'm not sure the Mackie is worth the money.. I'd like to try a QSC1400...they're cheaper...but even at that... I'm not sure I've got a reason to stop running my 400s.other than the rackability...can someone smarter than me (that's most of ya'll)...tell me what it is about the kustom amps that makes them sound tighter, punchier...and since I'm not able to go up to say an Eminence KAppa pro series (the kustom mounting posts are too short to make it through the speaker frame ) so I don't see me changing out my speakers...I"m using an nice AShley 3 way/sub electronic crossover which really lets me find the sweat spot in the cabs...I just think I'm looking at a whole different game to get into massive wattage solutions to get more bass...anyway.. as always I'm rambling...my whole point is really to say that 30 years on, I'm still way impressed with what comes out of my kustom amps..I've read the whole input voltage from signal source, dampening ratings...and the effect of planetary alignment on amp rms ratings...in the end..my ears and chest are still hearing good things from my tuck n roll...somebody 'splain it to me...ET
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Re: power amp questions [message #2319 is a reply to message #2313] |
Tue, 07 January 2003 01:11 |
KustomBlues
Messages: 490 Registered: June 2001 Location: Michigan
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Senior Member |
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Et, make a new back (just the wood, no vinyl necessary to experiment) for your cab and cut a 3" hole in the bottom corner area of the cab. It will allow for some more venting. If necessary, make the hole bigger. Let me know what you think.
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Re: power amp questions [message #2324 is a reply to message #2321] |
Tue, 07 January 2003 10:59 |
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great advice all...see , I knew someone would have the edge up on this....I do like the excuse of having a reason to get 2 more 2x15 cabs....but I guess I'll try getting some more air into these for now....budget ya know....ET
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Re: power amp questions [message #2481 is a reply to message #2312] |
Tue, 25 February 2003 00:16 |
Bill
Messages: 64 Registered: March 2002 Location: Kansas
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Not wanting to risk ruining my 2x15 JBL cabinet with the following experiment, this is what I did to my homemade 2x15 Kustom wannabe (loaded with Carvin PS15's) cabinet to get it to throw more lows.....
I built a 5 inch deep extension insert which lays inside the original cab one inch. The original back screws into the insert just as it did on the original cab. The port tubes are 12 inches, with the overall cab depth 19 inches now. Anyway, the idea of this endeavor was to come up with something that could be added to a normal cabinet, and be removed if it didn't work out, with out ruining a nice Kustom cabinet. It is on the back of the amp, so it is not really noticeable, unless a Kustom Krazy should happens by, and wonders what the deal is. By the way, I will be playing in Chanute next Saturday, with a pair of K200 amps.
Thrill Bill
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Re: power amp questions [message #2485 is a reply to message #2484] |
Thu, 27 February 2003 10:56 |
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thanks again for the input guys..my 2x15s are not mint...but only a bit rough around the lower edges and look great on stage...I have to give em credit they do well for most every gig our band plays.. I just remember seeing rigs like little 1x15 PV cabs..not big ones..but loaded with a single black widow getting slammed with high wattage and it would slap my chest big time..I don't think it had as much coverage or throw as my old cabs..but it was tighter and punchier and I figure a big part of that is the higher wattage..and with the PV cab not really affording much air space I'm wondering how much diff a set of really hi watt speakers powered with a ton of wattage would do..but then I tried loading an EMinence Kappa400 in my cab...but the speaker's rim is so thick that the mounting bolts on my kustom baffle aren't long enough to go all the way through! so I backed down to my good old 150 rms drivers. I guess these ol gals will hang with me for the next few years that I have of viability on stage...after that I'll be happy just to be a sideman guitar player and my kustom PA will retire to mystudio where late at night I'll drop an old Joe Cocker Mad Dogs CD on the system and throttle up my tuck n roll stereo
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Re: power amp questions [message #2487 is a reply to message #2486] |
Fri, 28 February 2003 13:25 |
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pretty bold claims... I gotta think they are going for the aural perception factor that I am struggling with...that ability to "smack" your chest with bass. Hopefully they'll come out with a similar driver in the 15 size and I can just do a straight replace....or hey...maybe I can make some custom kustom cabs for single 12s to stack on top of my 2x15s...naw..too much trouble..everybody'd want some and I'd have to go into business for myself making them..I mean..think about it..spending all day creating cool tuck n roll rigs...when I could be sitting at my desk stuck in this crappy job....I suppose some bass player in the bunch will try those new speakers in the little 2x12 cabs.. I only have two of those cabs right now and they are dedicated to guitar.. I'd have to buy more cabs to load the emi's in ...gee..wonder what's on ebay.....best go lool..
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Re: power amp questions [message #2488 is a reply to message #2487] |
Fri, 28 February 2003 16:29 |
C4ster
Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
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Senior Member |
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Well, here goes my 2 cents worth. I know the anti JBL contingent will be out but I have 2 E140's in a 3x15 siren cabinet and I have 2 cabs on either side of the stage. By themselves they give the kick you are looking for. The E's are very tight with a 100 dB sound pressure level measured at 1 meter with a 1 watt input. That isn't too bad. Also the 140's have a frequency range of 40-2500 Hz. These are in the siren cabs so I have more internal volume than the 2x15 cabs. I think that helps the frequency response and projection. The only problem is I need to cover the high bass region before I cross over to the horns. I have 4x12 columns with JBL E120's and the horns have to do very little work. I hit the cabs with 1100 watts on the 15's and 800 on the 12's. The sound is quite good. The 12's have excellent clarity. The only drawback to the system is the price of the speakers. I probibly spent $1000 on all of the speakers alone. Plus I had to recone 2 E140's because the knob who sold them to me, didn't know how to pack them. I should have sent them right back and demanded my money. Oh well, live and learn.
Conrad
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