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Title: QSC PLX 3102 for JBL speakers
Post by: László Rajzin on October 12, 2018, 06:18:35 PM
Dear All.

What amp would go well with JBL setup?
Tops: 2x JBL MRX 515 (400/800/1600w/8 ohm)
Sub: 2x  JBL MRX 518S 18” subs (400/800/1600 4 ohm)

Here is what I have found:
Top: Crown XTI 4002 (650w at 8ohm) or QSC PLX 3102 (600w at 8ohm)
Sub: Crown XTI 4002 (1200w at 4 ohm) or QSC PLX 2502 (this: 750w/ch at 4 ohm) or QSC PLX 3102 (1000w/ch at 4 ohm).

Sound quality is important to me.
I need just crossover, but this is in the QSC and XTI also...

I use it now 2 x XTI 2000 but ... I'm not happy with sub performance.
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Chris Grimshaw on October 12, 2018, 06:20:35 PM
This is the second time you've been told.
Sort out your displayed name. It's one simple rule that's all over the pages you clicked through to sign up here.

Chis
Title: Re: QSC PLX 3102 for JBL speakers
Post by: László Rajzin on October 12, 2018, 06:28:33 PM
This is the second time you've been told.
Sort out your displayed name. It's one simple rule that's all over the pages you clicked through to sign up here.

Chis

Sorry, it's ok! Thankyou. :)
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Don T. Williams on October 12, 2018, 06:46:14 PM
In general, the more power available for subs, the better they sound.  If your unhappy with your subs performance, I suspect it is not just a power issue!

If the amp (or a crossover/processor) has a High Pass filter in the 30 to 40Hz range for the sub, engage it.  That may help.
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Caleb Dueck on October 12, 2018, 07:11:15 PM
You say sound quality is very important, but you have lower end JBL, dual 15/horn (indistinct midrange), lower end subwoofers, and not enough subs vs tops. 

The amps you asked about aren't known as being solid performers on subwoofers.

You'll also need to get the crossover frequencies, slopes, delay times, and possibly polarity set well between subs and tops. 

Cost wise it would be close if you sold all those and buy some much better self-powered tops in the $1k-$1.5k range.  For subs - used Orbit Shifters or TH115's, powered by a Powersoft DSP amp. 

Sent from my VS980 4G using Tapatalk

Title: Re: QSC PLX 3102 for JBL speakers
Post by: Luke Geis on October 12, 2018, 09:05:41 PM
The simple answer is that any of the choices you presented will work just fine.

The XTI-2000 should be about perfect for the sub and tops providing about 750 watts at 4 ohms. Keep in mind that you would only have another 3db in output if you doubled that power to 1,400 watts, so buying another amp really won't get you anywhere.

All the amps you suggested are in the same league and neither will really outperform the other. While more power seems like the easy answer, it really isn't. While you should ideally have a little more than you currently do just for a little more margin, the truth is that even if you doubled the power you currently have, you would only get another 3db in output. The amps that you have are pretty good and the cost per watt with the features the amp has is about as good as it gets.

The performance you are lacking is because of the speakers. Unfortunately, you just don't own great speakers. They are good for beginners and for those that just want a PA that makes noise, but beyond that, they are just mediocre. If you are not happy with the subs, you would be best-suited buying a better sub, not a different amp.

Amplifiers these days are all pretty good and perform relatively close to one another within their market groups. I.E. buying a more powerful version of the same amp is essentially just spending more money on more wattage for the exact same amp. The XTI is the next best thing to Crowns upper tier I-Tech series. The XTI-6000 has some of the pedigree from the I-Tech line but is rather pricey and WAY too much amp for what you have. So you have what is essentially the best amp you can get for the money from that manufacturer. 
Title: Re: QSC PLX 3102 for JBL speakers
Post by: László Rajzin on October 14, 2018, 02:21:57 AM
The simple answer is that any of the choices you presented will work just fine.

The XTI-2000 should be about perfect for the sub and tops providing about 750 watts at 4 ohms. Keep in mind that you would only have another 3db in output if you doubled that power to 1,400 watts, so buying another amp really won't get you anywhere.

All the amps you suggested are in the same league and neither will really outperform the other. While more power seems like the easy answer, it really isn't. While you should ideally have a little more than you currently do just for a little more margin, the truth is that even if you doubled the power you currently have, you would only get another 3db in output. The amps that you have are pretty good and the cost per watt with the features the amp has is about as good as it gets.

The performance you are lacking is because of the speakers. Unfortunately, you just don't own great speakers. They are good for beginners and for those that just want a PA that makes noise, but beyond that, they are just mediocre. If you are not happy with the subs, you would be best-suited buying a better sub, not a different amp.

Amplifiers these days are all pretty good and perform relatively close to one another within their market groups. I.E. buying a more powerful version of the same amp is essentially just spending more money on more wattage for the exact same amp. The XTI is the next best thing to Crowns upper tier I-Tech series. The XTI-6000 has some of the pedigree from the I-Tech line but is rather pricey and WAY too much amp for what you have. So you have what is essentially the best amp you can get for the money from that manufacturer.
Thank you all.
what sub you would offer for me? Xti bridge 8ohm 1600w/ 4 ohm 2000w.
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Dustin Campbell on October 14, 2018, 01:14:47 PM
The simple answer is that any of the choices you presented will work just fine.

The XTI-2000 should be about perfect for the sub and tops providing about 750 watts at 4 ohms. Keep in mind that you would only have another 3db in output if you doubled that power to 1,400 watts, so buying another amp really won't get you anywhere.

All the amps you suggested are in the same league and neither will really outperform the other. While more power seems like the easy answer, it really isn't. While you should ideally have a little more than you currently do just for a little more margin, the truth is that even if you doubled the power you currently have, you would only get another 3db in output. The amps that you have are pretty good and the cost per watt with the features the amp has is about as good as it gets.

The performance you are lacking is because of the speakers. Unfortunately, you just don't own great speakers. They are good for beginners and for those that just want a PA that makes noise, but beyond that, they are just mediocre. If you are not happy with the subs, you would be best-suited buying a better sub, not a different amp.

Amplifiers these days are all pretty good and perform relatively close to one another within their market groups. I.E. buying a more powerful version of the same amp is essentially just spending more money on more wattage for the exact same amp. The XTI is the next best thing to Crowns upper tier I-Tech series. The XTI-6000 has some of the pedigree from the I-Tech line but is rather pricey and WAY too much amp for what you have. So you have what is essentially the best amp you can get for the money from that manufacturer.
I used the plx3002 for the jbl mp415 and had good results - for subs I would go rmx or heavy iron amp on the subs


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Title: Re: QSC PLX 3102 for JBL speakers
Post by: Luke Geis on October 14, 2018, 03:31:58 PM
Even if you bridge the amp, you won't get better results. Again doubling the power only nets a 3db gain in output.

A better sub would be anything in the mid to upper tier in the JBL, EV, QSC, et all line up. A JBL PRX-400 series passive box, or a passive EV Live X series would all be good options that are better than what you currently have.

Although, if I were you, I would just buy a powered box and keep the amps to use on monitors later on or something.
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Don T. Williams on October 15, 2018, 06:07:31 PM
Even if you bridge the amp, you won't get better results. Again doubling the power only nets a 3db gain in output.

A better sub would be anything in the mid to upper tier in the JBL, EV, QSC, et all line up. A JBL PRX-400 series passive box, or a passive EV Live X series would all be good options that are better than what you currently have.

Although, if I were you, I would just buy a powered box and keep the amps to use on monitors later on or something.

+1 for Luke's comments.  The newer active (powered) subs are a real step up in performance, with processing and power that is matched to the components used.  You get better reliability and some offer deeper bass (or what sounds like deeper bass).  Most of the major bands have good products.
Title: Re: QSC PLX 3102 for JBL speakers
Post by: László Rajzin on October 18, 2018, 11:37:26 PM
+1 for Luke's comments.  The newer active (powered) subs are a real step up in performance, with processing and power that is matched to the components used.  You get better reliability and some offer deeper bass (or what sounds like deeper bass).  Most of the major bands have good products.

Thank you for all!
Title: Re: QSC PLX 3102 for JBL speakers
Post by: Garry Wilson on October 26, 2018, 09:14:35 AM
Dear All.

What amp would go well with JBL setup?
Tops: 2x JBL MRX 515 (400/800/1600w/8 ohm)
Sub: 2x  JBL MRX 518S 18” subs (400/800/1600 4 ohm)

Here is what I have found:
Top: Crown XTI 4002 (650w at 8ohm) or QSC PLX 3102 (600w at 8ohm)
Sub: Crown XTI 4002 (1200w at 4 ohm) or QSC PLX 2502 (this: 750w/ch at 4 ohm) or QSC PLX 3102 (1000w/ch at 4 ohm).


XTI 4000 is fine for the tops, I'd get the Xti 6002 for the subs.

I have the XTi 4 & 6, as well as the QSC amps. I had the MRX as well. The QSC PLX series aren't the amps I'd use for subs, been there, done that.

Sound quality is important to me.
I need just crossover, but this is in the QSC and XTI also...

I use it now 2 x XTI 2000 but ... I'm not happy with sub performance.