Full Version: Question for Power Amp experts
So I am basically starting to improve the quality of my main PA rig, and the main system is a Martin Audio F12 and S15 (through a crossover limiter) rig powered currently by a C Audio pulse 1100 in Mono. Not ideal but, not bad. My intention was to get 1 super amp say a Lab Gruppen 6400 and again use in Mono (so using 1 side for subs and 1 for tops) as my C Audio has just started to develop faults (and I was intending to fase it out). My question is that, if I use the LG for Subs (higher wattage) and continue to to use the C Audio for tops is there musch difference in sound and quality "for what I need". What I need is a good vocal sound with a live 5 piece Pop Band and things like Kick drum and Bass guitar with a nice tight powerful sound for my size of rig. Or will there be a difference and a waste of a good amp, purely for the subs? Hope this makes sense.
Hi Steve
just my 2p
The s15 you mention has a rating of 750W AES, 3000W Peak. The Labs are obviously capable of delivering the 'watts'. However, there are amps out there that can deliver the same power you need, for less dosh. XTI4000's for example with the built in capability of DSP for similar weight? the electrovoice analogue range? have a look at the yamaha range aswell.
In short to your question (me and Rob Beech had a long discussion about this ironically the night before you posted), in a nut shell the sound that comes out will be different if you A/B the amps onto the same drivers and so forth. Think Harmonic distotion, Frequency anomalies, component difference etc, but these generally would be very minutte seeing the amps have the power capabilities. But seeing as your driving different speaker types (sub off one amp, tops of the other) it wont matter, just match your sub level to the desired amount with reference to your tops.
If you decide to drive one half of the amp for the sub, the other channel for the tops as per your mono'ing statement. Electronically thats fine, as the amp in question has (in my opinion) a good crosstalk rejection and has been stable when I've used it for similar purposes on monitoring applications.
If your C - Audio amp has developed faults, then maybe thats the option until you repair it or whatever?
HTH
Simon
QUOTE (simonwest @ 17 Aug 2008, 1:00 PM) 
Hi Steve
just my 2p
The s15 you mention has a rating of 750W AES, 3000W Peak. The Labs are obviously capable of delivering the 'watts'. However, there are amps out there that can deliver the same power you need, for less dosh. XTI4000's for example with the built in capability of DSP for similar weight? the electrovoice analogue range? have a look at the yamaha range aswell.
In short to your question (me and Rob Beech had a long discussion about this ironically the night before you posted), in a nut shell the sound that comes out will be different if you A/B the amps onto the same drivers and so forth. Think Harmonic distotion, Frequency anomalies, component difference etc, but these generally would be very minutte seeing the amps have the power capabilities. But seeing as your driving different speaker types (sub off one amp, tops of the other) it wont matter, just match your sub level to the desired amount with reference to your tops.
If you decide to drive one half of the amp for the sub, the other channel for the tops as per your mono'ing statement. Electronically thats fine, as the amp in question has (in my opinion) a good crosstalk rejection and has been stable when I've used it for similar purposes on monitoring applications.
If your C - Audio amp has developed faults, then maybe thats the option until you repair it or whatever?
HTH
Simon
just my 2p
The s15 you mention has a rating of 750W AES, 3000W Peak. The Labs are obviously capable of delivering the 'watts'. However, there are amps out there that can deliver the same power you need, for less dosh. XTI4000's for example with the built in capability of DSP for similar weight? the electrovoice analogue range? have a look at the yamaha range aswell.
In short to your question (me and Rob Beech had a long discussion about this ironically the night before you posted), in a nut shell the sound that comes out will be different if you A/B the amps onto the same drivers and so forth. Think Harmonic distotion, Frequency anomalies, component difference etc, but these generally would be very minutte seeing the amps have the power capabilities. But seeing as your driving different speaker types (sub off one amp, tops of the other) it wont matter, just match your sub level to the desired amount with reference to your tops.
If you decide to drive one half of the amp for the sub, the other channel for the tops as per your mono'ing statement. Electronically thats fine, as the amp in question has (in my opinion) a good crosstalk rejection and has been stable when I've used it for similar purposes on monitoring applications.
If your C - Audio amp has developed faults, then maybe thats the option until you repair it or whatever?
HTH
Simon
Thanks Simon, if I get my C Audio repaired would you recommend using this as well as say a L Gruppen, or is it overkill and better value for say 2x Crown XTI 4000's?
personally, if I had the cash. a couple of XTi's would be preferable. as they have built in xovers, processing etc(although I havn't actually asked yet, what xover you got or?). They are lightweight, and you can recall the presets you make. Such as if you make adjustments for a particular venue maybe. Also, should you use another loudspeaker type, add monitors...whatever. they are flexibile and efficient to say they still run very well on minimum mains current draw. Very good for them 'one 13amp socket' venues.
Rob Beech has, several lets say. He'll share his opinion im sure as always.
The main thing is, as a pratical engineer whos had to fix amps / repair amps on a large show over night so the show can be ready the next day.... 2 amps in your predicament = 1 spare if the rig is run in mono should one go down. Obviously I know with 2 amps you'll run in stereo from the start and not just leave one sitting there, but should one ever go belly up the XTI's will more than cope running the rig on one amp.
should you fix the c audio.... the same advice applys, if you have 2 amps on such a rig..why not use them / take them. one spare is better than no spare.
HTH
Simon
Rob Beech has, several lets say. He'll share his opinion im sure as always.
The main thing is, as a pratical engineer whos had to fix amps / repair amps on a large show over night so the show can be ready the next day.... 2 amps in your predicament = 1 spare if the rig is run in mono should one go down. Obviously I know with 2 amps you'll run in stereo from the start and not just leave one sitting there, but should one ever go belly up the XTI's will more than cope running the rig on one amp.
should you fix the c audio.... the same advice applys, if you have 2 amps on such a rig..why not use them / take them. one spare is better than no spare.
HTH
Simon
Both the C Audio and Lab Gruppen brands are renowned for audio fidelity. In fact some of Martin Audio's own in-house badged amps are (or were) made for them by Lab Gruppen. You can't really go wrong.
I highly recommend the Crown XTi's...they are a great bang for your money. We are running 6 Crown XTi-2000 (4 are Bi-Amped and 2 are in Stereo) at my work into our 8 Main Renkus-Heinz Speakers and they sound incredible! I would get 2 XTI's and then you can run everything in Stereo or Bi-Amped mode! The onboard DSP is great and easy to work with, it uses USB and Harmon HiQNET System Architect which also is what our DBX Driverack 4800 uses for control.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.