Crest CA9 Lovers speak up.

[Bob Lee (QSC)]

No, if you don't deliberately match gains, then the high probability is that your gains aren't then matched by accident. Then the likelihood that a gain mismatch causes one amp to sound louder than the other is almost certain. And since human ears essentially have SPL-dependent EQ, especially in the low end, an apparent difference in bass response can't logically be pinned on the amps.

Does the Yamaha amp have a bass roll-off? I doubt it, but there's no way of knowing from an experiment like that.

 

[joegeezer]

As the CA9 is 18 inches long, I run the Carvin DCM2500, only 11 inches long. Makes a smaller package to stack on the cabs. If not for that one reason, I'd have a CA9. The CA9 has just a spec more juice than the Carvin, but not much. I also get the big low end. Tried all the lite weight amps, I'd like to not have to have help getting it on top my cabs, but it's worth every grunt, to have the big power. I won't be changing anytime soon.

 

[Bob Lee (QSC)]

Some of us have big power but no lead sled.

 

[Red Planet]

No, if you don't deliberately match gains, then the high probability is that your gains aren't then matched by accident. Then the likelihood that a gain mismatch causes one amp to sound louder than the other is almost certain. And since human ears essentially have SPL-dependent EQ, especially in the low end, an apparent difference in bass response can't logically be pinned on the amps.

Does the Yamaha amp have a bass roll-off? I doubt it, but there's no way of knowing from an experiment like that.

I'm not walking around with a closed mind though I'm skeptical after our discussion about Surge/Spike Protection when I have real world results to prove beyond a shadow of a doubt what the facts are.


But now you are telling me (not refering to Gain Matching specifically) I need some sort of secret code to unlock the Power in the Yamaha? It's not enough to say the RMX 2450 just has way more arse? So the Yamaha has less gain than the QSC? Then you would think I could bring up the Level either Master out of my Pre or at the Amp and solve the Problem, would I not? As well as I have tried Pulling the Input level down a turning up the Master on my Pre but I get the same results. I am not running out of Master Level from my Pre and am not ovedriving or underdriving anything.

So the QSC has more gain?

 

[DEVILMAN]

Since Peavey has took over Crest, is there any difference in a modern/new CA9 compared to a pre-Peavey piece?

~S~

 

[gregbackstrom]

The CA9 in particular is voiced to have a heavy bass response.

Is there a measurement available that shows the bass-heavy response curve ?

Thanks!
Greg

PS I LOVE my VB-2, BTW!

 

[Mark Reccord]

I'm not walking around with a closed mind though I'm skeptical after our discussion about Surge/Spike Protection when I have real world results to prove beyond a shadow of a doubt what the facts are.


But now you are telling me (not refering to Gain Matching specifically) I need some sort of secret code to unlock the Power in the Yamaha? It's not enough to say the RMX 2450 just has way more arse? So the Yamaha has less gain than the QSC? Then you would think I could bring up the Level either Master out of my Pre or at the Amp and solve the Problem, would I not? As well as I have tried Pulling the Input level down a turning up the Master on my Pre but I get the same results. I am not running out of Master Level from my Pre and am not ovedriving or underdriving anything.

So the QSC has more gain?

It does. The methods used to rate the power outputs of two amps in question are different so it's hard to gauge just how equivalent they actually are.

What you're experiencing may have to do with the overload characteristics of the amps. If you're running loud at all, you're likely to be clipping the amp on transients and some amps deal with this more gracefully than others do. More graceful clipping behaviour means better sound at the edge. This has more to do with output stage design than type of power supply, though. So, I don't think that you can automatically attribute it to the amp's lead sledness.

I do think that power amplifiers are largely equivalent when operated entirely in their linear ranges. Unfortunately, in the real world this isn't always the case (more often than not it isn't). You might be surprised at how often your power amp hits its limits even when not playing that loud. On transients the amp may indeed clip without the indicators coming on.

 

[JGR]

the gain matching thing always comes up - if crest's design makes it "appear" to sound better, why don't other companies use a similar gain structure to allow their products to get the same results without all the hassel like the crest does?

 

[pickles]

If you're running a solid state power amp anywhere near clipping, all bets are off. If that is happening you should get a more powerful amp, end of discussion. We're talking about response in the linear range of the amp.

All the skeptics should read my posts on this before and after I bought a dummy load and learned how to gain match. I was SURE that the CA sounded "bigger, fatter, clearer". Gain match and blind A/B/X --> all the differences were instantly gone. If I messed with the gains to make them even a tiny bit off of identical (like if the attenuator slipped into one of the detents kind of small changes), then my ears picked up all kinds of weird differences. Gotta remember your speakers respond to differences in output too!

The CA is a great amp, and offers lots of watts per $. The PLX costs a little more, weighs less, and has a nicer feature set. Pretty simple choice that each person will make differently.

 

[Bob Lee (QSC)]

I'm not walking around with a closed mind though I'm skeptical after our discussion about Surge/Spike Protection when I have real world results to prove beyond a shadow of a doubt what the facts are.


But now you are telling me (not refering to Gain Matching specifically) I need some sort of secret code to unlock the Power in the Yamaha? It's not enough to say the RMX 2450 just has way more arse? So the Yamaha has less gain than the QSC? Then you would think I could bring up the Level either Master out of my Pre or at the Amp and solve the Problem, would I not? As well as I have tried Pulling the Input level down a turning up the Master on my Pre but I get the same results. I am not running out of Master Level from my Pre and am not ovedriving or underdriving anything.

So the QSC has more gain?

I don't know. We can't tell much from your experiment.

 

[alexclaber]

I do think that power amplifiers are largely equivalent when operated entirely in their linear ranges. Unfortunately, in the real world this isn't always the case (more often than not it isn't). You might be surprised at how often your power amp hits its limits even when not playing that loud. On transients the amp may indeed clip without the indicators coming on.

Exactly!

Bothering about such fine details differentiating power amplifiers does seem a little crazy to me when the speaker is by far the weakest link in the chain. It's all very well believing that one amp can produce more power than an other despite the specs being near identical but I'd like to see the speaker cab that can really make use of that alleged extra power!

Alex

 

[seamonkey]

The CA9 is EQd with a bass boost? If it's true, that's very strange for a power amp.

That's a shame. I hope Peavey has better discipline on their other amps.

 

[greenboy]

Exactly!

Bothering about such fine details differentiating power amplifiers does seem a little crazy to me when the speaker is by far the weakest link in the chain. It's all very well believing that one amp can produce more power than an other despite the specs being near identical but I'd like to see the speaker cab that can really make use of that alleged extra power!

Alex

I gotta laugh when I see guys carrying on about high-bux cables - even AC ones! - when their cab of choice is just one hella of a bottleneck anyway! ; }

 

[seamonkey]

the gain matching thing always comes up - if crest's design makes it "appear" to sound better, why don't other companies use a similar gain structure to allow their products to get the same results without all the hassel like the crest does?

+1
They all should follow the same standards but consumer need to demand it.

 

[Red Planet]

I don't know. We can't tell much from your experiment.

Ahhhh but I can and thats all that really counts is'nt it?

I'm not trying to state Gain Matching dosnt work. What I am saying is I dont think it's going to change anything about the Yamaha.

I would tend at this point to agree with what Mark said. The Peak Indicators are coming on, on the RMX 2450 but that dosnt seem to be bothering anything. No harsh high end slap.

As far as needing a better Cab I will have to absolutely dissagree. I'm using the new SWR 4 ohm Goliath IV 4X10 rated at 800 watts and let me tell you it will take everything the QSC RMX 2450 Can dish out (bridged mono at 4 ohms) without acting like it's even being puched hard. Not sure why, you would think I would be overexcursing but I'm not.

My two Previous cabs a Mesa Powerhouse 4x10 and an Ampeg 4x10 HLF would be dead by now. They could not take my QSC RMX 850 let alone the 2450 but the SWR gobbles all that power up. The SPL's are rated at 105 db.

The Yamaha starts loosing it and clipping when I start pushing it hard. I'm not saying it's a bad amp and it may very well serve a Purpose for me in the future but the RMX 2450 just blows it away.

Problem is I dont like yanking my 2450 out of my PA so I'm currently pursuing a deal for a CA9 from a fellow TBer.

 

[Red Planet]

+1
They all should follow the same standards but consumer need to demand it.

Agreed.

Here is a question.

Why do all the Lightweight Amps need secret decoding when it comes to "Gain Matching" and all the Heavy Weight Amps are set up similar to each other?

 

[Red Planet]

Also as far as "My Experiment" goes concerning trying to get the Yamaha to give up the goods, I'm not halucinating.

 

[Kindness]

Here is a question.

Why do all the Lightweight Amps need secret decoding when it comes to "Gain Matching" and all the Heavy Weight Amps are set up similar to each other?

Input sensitivity usually tells the story. Cross reference your "findings" with the amps' input sensitivity and see if you find a trend. Most people that don't know better find the amps with the lowest input sensitivity to be the loudest/most powerful. Of course, once that variable is accounted for, the game changes.

 

[seamonkey]

Agreed.

Here is a question.

Why do all the Lightweight Amps need secret decoding when it comes to "Gain Matching" and all the Heavy Weight Amps are set up similar to each other?

On the other hand. A little tweak of the gain and you can get one amp to sound to your ears just like another. These really ought to be blacked boxed and the user shouldn't care what's actually inside. A cheaper amp may be as good as expensive. Lightweight as good as heavy, ...

 

[OldogNewTrick]

No, if you don't deliberately match gains, then the high probability is that your gains aren't then matched by accident. Then the likelihood that a gain mismatch causes one amp to sound louder than the other is almost certain. And since human ears essentially have SPL-dependent EQ, especially in the low end, an apparent difference in bass response can't logically be pinned on the amps.

Short derail/sidetrack:
how exactly do you match gain structures ? - procedures ? tools ?

If you run well within the comfort zone of your amp, does it make any difference ?