QSC MX2000a for RT3000p?

ChrisD06

Just as the title states. The amp does FTC 450W RMS and EIA 475W RMS, I know the RT3000p handles up to 500W but has anyone actually driven them up that high?

Also, would the MX1500a which is FTC 350W RMS cause any damage to my RTi70 and CS400i? They're both 250W RMS, but I'm curious if you can push them further and Polk was just being conservative.

txcoastal1

I would say no
Most spec’s are PEAK
Besides that at sustained high levels induces heat to the speaker coils and the crossover
When clipping occurs it can also damage your headend components

Emlyn

The QSC amps aren't really designed for home use but can be used for that purpose if someone wants to. People usually pick those because they're relatively inexpensive and the continuous output ratings are high. They'll work fine with any Polk RT series speaker.

In home use even if an amp is capable of enormous power output the speakers aren't going to use it. The recommended amplifier output range for speakers is just a suggestion to give buyers and sales people an idea of what gear to go along with the speakers. Some expensive 20 watt amps have more current capability than cheap 100 watt amps. A speaker can fail regardless of amp selection if it's abused by too much being asked of it on the volume dial.

ChrisD06

@txcoastal1 I know someone driving the CS1000p with a 250W RMS Amp, which is the max it handles, and it sounds amazing and has lasted years. Perhaps Polk really did list continuous? Might be a question for Ken

ChrisD06

@Emlyn I'm only getting them because they're good and cheap, and it's better than my AVR. I could get the MX15000a with 350W RMS and use that on my RT3000p. If they handle 250W, I'm inclined to believe Polk listed the continuous spec. Also, the SRT handling 1.5kW was also supposedly continuous, I saw a post of someone driving them with I believe 1100W?

They're definitely not for home use, but all the more reason to use them. They'll run cooler in a less intensive environment and they're cheap and simple, along with some good protection features.

F1nut

You have much to learn.

ChrisD06

@F1nut Teach me! I'm always willing to learn. In all fairness to myself, I started this hobby when I was 14 years old, back in 2020 during the pandemic. If the QSC isn't a good buy, please tell me so I don't learn the very hard way.

VR3

Pro amps are meant for volume, not fidelity... To put it simply.

ChrisD06

@VR3 Any recommendations then? Want something at least 200W RMS that could drive both speakers.

Clipdat

RMS? Are you coming from the car audio world?

VR3

Rt3000p tops don't even play full range... They don't need much power

pitdogg2

May want to quit thinking in terms of RMS and more in terms of current delivery.

ChrisD06

@Clipdat No, this is just how I learned it, I also see wattage measurements listed as RMS, especially with subwoofers for HT.

@VR3 I'm aware they cut out at 80Hz, but if they can take some juice then why not give them the juice? Also the midwoofers would perform better in the midrange aspect with more wattage would they not? This is what I've been told.

@pitdogg2 So focus more on the amps delivered rather than the wattage?

VR3

I have a crown xti4002 pushing my subwoofers and a mark Levinson pushing my 2 channel mains.

The ml has a fraction of the power but tremendous amounts of current and control

ChrisD06

@VR3 So after some research I'm seeing that current controls the drivers better and wattage allows the speakers to play louder without distortion.

So I could in theory use a 20W amp with tons of current and have better sound than a 200W amp with barely any current?

If so, I know you know the driver measurements for the RT3000p sattelites. Could you confirm if their 500W power handling is peak or continuous, and if so, how much voltage and current they can handle safely? I'll stop looking at wattage (probably will look for 150W), and start focusing on current.

This makes so much more sense now, it's actually answering tons of questions I had!

VR3

I have owned the rt55i which is the full range version... I ran out to eat bleeding levels with 60 quality watts.

You truly don't need that many watts to obtain distortion free volume.

pitdogg2

So I could in theory use a 20W amp with tons of current and have better sound than a 200W amp with barely any current?

yes!

ChrisD06

@pitdogg2 Awesome! I'm getting this now. See, I always knew more voltage to the speaker meant louder volumes, and that the volume knob controlled how much voltage went to the speaker, but I was always so confused how an amp would output 350W at a lower volume and how that would even make a difference. This makes perfect sense. Voltage is volume, current stays the same, wattage goes up with more volume as the voltage goes up. It literally removed a genuine headache from trying to wrap my head around that.

@VR3 All I know is the QSC MX2000a can output up to 60V at 7.5A for a total of FTC 450W continuous in 8 ohms. Is this considered high current or should I search elsewhere? I did the math to find this number by the way. 450 = V^2/8, which is 3600 = V^2, which is 60 = V, and 450/60 is 7.5

My Onkyo currently goes up to 28.3V at 3.5A for a total of FTC 100W continuous into 8 ohms. So I think the QSC would be an upgrade no matter what, and I assume the RT3000p could definitely handle it, so is it still not a great idea to go for it, or should I try it out anyways? They're cheap as hell, like I could flip them for profit if they don't work out.

Clipdat

How are you planning on hooking up an amplifier to the Onkyo TX-NR656 when that AVR doesn't have any pre-outs?

VR3

A truly high current amp will double wattage as the load drops

The qsc is 450 and 650 with no 2 ohm rating

A true high current amplifier would do 450, 900, 1800 8/4/2

VR3

But even this only tells part of the story... A well engineered amplifier just sounds better

ChrisD06

@Clipdat Intending on getting a pre-processor. Was going to pick up an MX2000a and two MX1500a to drive my center, surrounds, and fronts, and then get a Yamaha pre-processor.

ChrisD06

@VR3 Gotcha. So I take it in terms of home theater usage, I should look elsewhere in terms of amps?

VR3

Yes.... They work great for subwoofers though

Clipdat

ChrisD06 wrote: »

@Clipdat Intending on getting a pre-processor. Was going to pick up an MX2000a and two MX1500a to drive my center, surrounds, and fronts, and then get a Yamaha pre-processor.

I don't understand why you think you need/want that much power.

ChrisD06

@Clipdat Home theater. I want the speakers to go loud. Eventually I'll have a larger room too (like, could fit a 9.4.6 SRT system large) so I figured why not future proof.

To be fair the amps are old, so the caps in then are probably EOL by now anyhow.

Clipdat

The speakers don't go loud currently?

VR3

How big is your room?

I can run my in ceiling system with in floor subwoofers to spine crushing volumes off of a receiver...

ChrisD06

@Clipdat The AVR starts to clip high frequencies violently at 60% volume or more. Only when bass is processed though, and depending on how low/loud the bass is.

VR3

Have you considered pro audio speakers?

They can hit 120db with relatively little power

Clipdat

Check the AVR settings to make sure L, R, and C are set to "small" or manually set the HPF to 80hz and up.