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Crest CA9 Lovers speak up.

#101
lo-freq said:
What that probably means is 3dB or 6dB down at like 20Hz and drops off the cliff below that (subsonic filter).
Click to expand...

Not sure I looked. It's kind of sketchy. Dosnt really say.

Taken from the Manual.

Subsonic Frequencies.
Built-in high pass filtering provides subsonic frequency protection for each channel. In addition, a relay will
open if excessive subsonic energy appears at the output.


Do not drive any low-frequency speaker enclosure with frequencies lower than its own tuned frequency; the
reduced acoustical damping could cause a ported speaker to “bottom out” even at moderate power. Consult
the speaker system specifications to determine its frequency limits, and employ a roll-off filter if necessary.


TourClass Protection

ACL, IGM, AutoRamp, short circuit, DC voltage, turn-on/off transient, current inrush, sub/ultrasonic input
 
#102
alexclaber said:
Exactly. These systems are complicated and non-linear and to make global statements is rarely useful but if you just try the gear and work out what works for you then that's often the best route to the solution.

So it seems clear that the QSC is working better for Mr Planet, which is great because it isn't that big or heavy and he already owns it. Sorted!

Alex
Click to expand...


Agreed. I do not want anyone to think my statements are all incusive. The QSC is just working better in this situation. Though given that the CA9 dosnt seem to have a built in High Pass Filter at least at 30 or 50 hz maybe I need just to get another QSC.
 
#103
Red Planet said:
Agreed. I do not want anyone to think my statements are all incusive. The QSC is just working better in this situation. Though given that the CA9 dosnt seem to have a built in High Pass Filter at least at 30 or 50 hz maybe I need just to get another QSC.
Click to expand...

There may be some merit in those filters if you're a four-string player only. At least with my five-strings, I've found that my QSC PLX 2402 sounds better with the filters off. I haven't found much use for the filters over time. I've had SWR, Eden, Acme, Mesa and Epifani cabinets, and I've never damaged a driver. So I don't think you need filters to avoid damaging speakers -- just ears!

Having said that -- and having heard all the gain-matching commentary from the various parties -- I still get a greater sense of "slam" with my CA9 than I do with my other power amps. There just seems to be more focus and heft from this amp in the very low end. Whether that effect is caused by input sensitivity, lack of filtering, or strictly psychosomatic causes I'm not sure. However, since these amps are pretty inexpensive used (I think you can get one right now from Dave Funk for $450-ish), you might want to play one before plunking your hard-earned $$$ on something else.

Just trying to help a fellow bassplayer!

- Greg

PS I'd make you a really good deal on my like-new PLX 2402 if you're interested!
 
#104
gregbackstrom said:
There may be some merit in those filters if you're a four-string player only. At least with my five-strings, I've found that my QSC PLX 2402 sounds better with the filters off. I haven't found much use for the filters over time. I've had SWR, Eden, Acme, Mesa and Epifani cabinets, and I've never damaged a driver. So I don't think you need filters to avoid damaging speakers -- just ears!

Having said that -- and having heard all the gain-matching commentary from the various parties -- I still get a greater sense of "slam" with my CA9 than I do with my other power amps. There just seems to be more focus and heft from this amp in the very low end. Whether that effect is caused by input sensitivity, lack of filtering, or strictly psychosomatic causes I'm not sure. However, since these amps are pretty inexpensive used (I think you can get one right now from Dave Funk for $450-ish), you might want to play one before plunking your hard-earned $$$ on something else.

Just trying to help a fellow bassplayer!

- Greg

PS I'd make you a really good deal on my like-new PLX 2402 if you're interested!
Click to expand...


Thank you for a well thought out post. A voice of reason no doubt. My name is Greg as well. I'm definately going for a heavy weight amp at this point. I'm in no hurry. Dont have any gigs booked with my PA right now but I will be selling the Yamaha and replacing it somehow ever whicha way.

I do Play Four String Bass. I mostly Play Classic Rock, Blues, and other related Original Tunes so the Four really works for me.

With the filters Off at the Volume I was Playing I could tell my Cab was ready to fall explode. The Low End was too much. Just by turning it onto 30 hz it eased things up a little. At 50 hz some of the Sub Boom was gone but the Tone got really Tight sounding. Those little Switches are handy.

Though the CA 9 dosnt have the 30/50 hx filters it slightly less power at 2,000 watts Bridged into 4 ohms as opposed to the QSC at 2400 watts. It might do the trick.

Has anyone ever directly compared the CA9 with the RMX 2450? If so what were your results????
 
#105
Red Planet said:
...

Has anyone ever directly compared the CA9 with the RMX 2450? If so what were your results????
Click to expand...

You might want to start a new thread with that title -- might get a wider audience.

If you're still considering an RMX bridged, I'd suggest the RMX1850HD.
When I got my 1st power amp, that's what I was really wanting, but the store where I got the rest of my system only had the PLX series in stock and gave me a good deal on one (still regret the change, though).
The 'HD' models are over-engineered for hard-driving individuals like yourself (there is an RMX4050HD, but talk about over-kill).

I also ran my PLX bridged and with no filters or limiting (I also play a 5 string). I had it shutdown on me a couple of times in the Texas summer heat during a couple of outdoor gigs.
I started carrying a stand fan that I set behind my rack and never had another protection time-out after that.
 
#108
Red Planet said:
Why not consider swapping the 5 ways to Speakons? It could easily be done. The only reason I would do that is for set up convenience. I dont care for spades, bannana plugs or bare wires into 5 ways. For me it takes too much time setting up for a gig. The Speakon is quick, easy, and a dang good connection.
Click to expand...

Swapping the output terminals on a 2000w amp is not something that is in my electronic playbook. I'd simply buy an amp that comes with speakons to begin with.

I was curious about this Yamaha you're using (which I had never heard of), so I search the specs on it. Rated power on that amp is at 1% THD. QSC uses 0.1%. The yamaha site also says:

THD+N (20Hz - 20kHz, half power): Maximum 0.1%

Whereas QSC is giving rated power at that 0.1% THD level. So it sounds like it is really about half as powerful as a PLX of the same rating ... about like an 1802 at best. It simply is not as powerful as the RMX, and not as nice of an amp.

Yes, with a PA style solid state amp you want it to produce more power than you could ever need so you keep it way out of clipping. THD from a solid state amp is not something you want in your tone, ever.
 
#109
Thanks very helpful.

I may need to turn my sights towards the 1850HD.

I belive from what I currently understand it would deal with Hot Environments better than the 2450 and does have the HiPass Controls that the CA9 dosnt.


I saterted another thread so I will check in on that. Looking at TB from my crackberry so its a littel more dificult. On my way to a Gig right now.
 
#110
gregbackstrom said:
I love (and hate) my CA9! The weight does bug me. To make moving it more manageable, I've put it in a two-space Gator rack with rear rack rails attached. I move it around via a dedicated portable, foldable hand truck, attaching it with a bungie-cord. I know it's only 47 lbs, but it's still heavy.

But it also SOUNDS heavy. Like nothing else I've ever heard. I've had Crown, Mackie, QSC and Stewart (World 2.1) amps, and the CA9 is my favorite. I'm currently using mine with a Michael Pope Designs MPP-1 preamp, and it's like the voice of God (who thinks I should attend church more often, BTW).

Seriously, this amp is the real deal! There's no sonic reason not to get one!

- Greg
Click to expand...

+1....I use mine with a Millennia STT-1 and WOW!
 
#112
47 pounds indeed it is. Since my other thread got locked I brought this one back from the dead.

For those that missed it, I got a CA9 and the CA9 kicks the Balls out of my RMX2450 and my Yamaha P5000S but I'm sure it is because the gain hasnt been properly matched.;)

What an Amp. The Crest Audio CA9 is one of the freakin beefiest hammering Chineese Crescent kicking, rip your Jugular Vein out in 1/2 a second and your dead, balliest Amps I have ever heard. To put it mildly.:D
 
#116
Red Planet said:
Bob your just not gonna give up til I try another Lightweight Amp?
Click to expand...

No, the CA series is lightweight compared to the Pro Series. If the CA series is a lead sled, the Pro is plutonium.

But, the Professional Series amps have a much lower gain than the CA. So using one would be sort of an audio IQ test--can you figure out how to make it work it's best?
 
#117
Yeah turn up my Master Volume.

Wow not sure if I could have figured that one out.

I said PL2 3602.

That being said all Gain aside the CA9 yielded way different results than the RMX 2450 in the same rig. Cranking the master seemed to get a little more distortion and less clean headroom than the CA9 with a lower Master Volume Level on my Pre. It also had more thump. Now I full well conceed that this was not done with matched gains though I believe it would take some modification to the 2450 to get it to match the CA9 gain and at least to me that would be a more truer way of leveling the playing field rather than lowering the gain of the CA9.

You would then know if the goods were the same as well as knowing if there were some minute plus to a hotter gain or not. To me if you lower the gain of the CA9 it really would not answer the question.
 
#118
That's why I suggested trying out a Crest Professional Series amp; if you have a psychological bias toward heavier amps, then you'll tend to favor the Pro over the CA, and if you don't care to or don't know how to match gains for a direct comparison you'll tend to favor the CA over the Pro.

There's nothing wrong with turning one amp's gain down to match the other amp it's being compared to. In fact, unless the amps happen to have exactly the same gain, it's absolutely necessary for determining whether the sonic "goods" are the same.
 
#119
No need for an Amp heavier than I can lift.

Bob Lee (QSC) said:
There's nothing wrong with turning one amp's gain down to match the other amp it's being compared to. In fact, unless the amps happen to have exactly the same gain, it's absolutely necessary for determining whether the sonic "goods" are the same.
Click to expand...

Yes and no. I understand fully what you are saying.

Here is where the difference comes in that can not be compared that way.

Follow me on this now.

Lets say I am Biased into thinking there is some merit to be had by the Lower Gain Sensitivity of the CA9. In other words there is actually something to be had with extra added Gain of the Crest.

If I were to truly address this myth/school of thought, I would need the Amp I'm comparing to it to have the same Gain of the CA9.

For this examples sake lets say the QSC RMX1850HD since the wattage is close to the CA9 IIRC.

Now the only way to truly decide wether the extra gain does anything extra special or not is to compare another amp set at the same Gain Level of the CA9, through the same rig, and I believe a Blind Test would be helpfull as well as actually Matching the Gains by measuring them.

Also as a side note it would be good to compare an equal wattage Lightweight QSC Amp and Lightweight Crest Amp. All at the Higher Gain settings.


Right now (to be honest), the biggest obsticle to me trying a Lightweight Amp is money. I would actually enjoy doing an Actual Matched Gain set of Amps though I think I would prefer to match them at the Higher Gain settings and try them. There, one could allways (in the same test) do a Lower Equal Gain Test as well.


Here is a test I could Probably do. Can the RMX 2450's Input Sensitivity be modded to the same as the CA9? I could probably swing that myself, if someone could tell me the value of parts and where to put them, then make the measurements. Though with the slight wattage difference (though it could be measured at equall points) and the difference of the Switchable High Pass/QSC and Non Swithcable on the CA, which is a slight unknown. I think you said it's maybe only 5 Hz in the CA9 but it does not sound like it to me. If I switch off the 30 Hz in the QSC, it is then too Low for my Cab and the CA9 is not too Low but seems more Powerful.

I know I have a tendency to go on and on. Oh well.
 

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