Think I could use help running my Crown XLS 1502's correctly

[Danzilla31]

Another thought, where do you have the amps? There is a warning about placing them too close to pre-amps or tape decks or other gear that might be compromised by the amps' magnetic field...




I've never heard of "standard tweeter hum from a class D". Where did you get that? Descriptions can be hard, but the description sounds more like ground loop hum than typical amp hiss.

How did you measure dynamics? How do you come to that conclusion?

I ask about speakers only because very high sensitivity speakers have been known to have audible hiss with these amps.

Have you tried lifting the ground on the Crowns? Does the Emotiva have a three prong plug?




I also wonder did you re-calibrate in between each change of amp?

Yes I do recalibrate

Hmmmmm a ground loop you say? There plugged into the dedicated 20amp circuit I had put in for them so there not sharing anything but it is more like a hum or a high pitch whine now that you mention it then a hiss. Like you said hard to put it into words

The amps are on top of the rack right now above the Emotiva amp could that be an issue? Here's a pic.

 

[Danzilla31]

Another thought, where do you have the amps? There is a warning about placing them too close to pre-amps or tape decks or other gear that might be compromised by the amps' magnetic field...




I've never heard of "standard tweeter hum from a class D". Where did you get that? Descriptions can be hard, but the description sounds more like ground loop hum than typical amp hiss.

How did you measure dynamics? How do you come to that conclusion?

I ask about speakers only because very high sensitivity speakers have been known to have audible hiss with these amps.

Have you tried lifting the ground on the Crowns? Does the Emotiva have a three prong plug?




I also wonder did you re-calibrate in between each change of amp?

When I was researching them I heard mentioned in a couple reviews that you can have noise from the tweeter when they are not playing and this is common for pro amps like this on home theater equipment. This Andrew guy on YouTube was one of the reviews he really spoke highly of these amps which got my attention on them in the first place

Just like he said before I turned down the gains when I'd play something you couldn't hear it but you could if everything was not playing so I just thought that's what it was

 

[Danzilla31]

Another thought, where do you have the amps? There is a warning about placing them too close to pre-amps or tape decks or other gear that might be compromised by the amps' magnetic field...




I've never heard of "standard tweeter hum from a class D". Where did you get that? Descriptions can be hard, but the description sounds more like ground loop hum than typical amp hiss.

How did you measure dynamics? How do you come to that conclusion?

I ask about speakers only because very high sensitivity speakers have been known to have audible hiss with these amps.

Have you tried lifting the ground on the Crowns? Does the Emotiva have a three prong plug?




I also wonder did you re-calibrate in between each change of amp?

The emotiva is 2 pronged every one of them I've bought from Emotiva is.

If it turns out to be a ground loop how is it fixable?

 

[Danzilla31]

I remember you saying that about audyssey. Just was wondering about the level match. Not sure about your him issues. It’s not likely the case, but I had an rca cable that was wonky that caused me some hum issues. That was a subwoofer though so... I guess if you can’t hear it at the LP, don’t sweat it. Maybe?

Yeah you can't hear it from there or when things are playing hmmmm getting ready to try some things holler back at you guys in a bit

 

[Danzilla31]

Another thought, where do you have the amps? There is a warning about placing them too close to pre-amps or tape decks or other gear that might be compromised by the amps' magnetic field...




I've never heard of "standard tweeter hum from a class D". Where did you get that? Descriptions can be hard, but the description sounds more like ground loop hum than typical amp hiss.

How did you measure dynamics? How do you come to that conclusion?

I ask about speakers only because very high sensitivity speakers have been known to have audible hiss with these amps.

Have you tried lifting the ground on the Crowns? Does the Emotiva have a three prong plug?




I also wonder did you re-calibrate in between each change of amp?

Oh and also the speakers are SVS prime towers which really aren't that efficient I believe I don't think there known to be very sensitive from what I understand

 

[lovinthehd]

Oh and also the speakers are SVS prime towers which really aren't that efficient I believe I don't think there known to be very sensitive from what I understand

87dB which is somewhere in the middle I suppose. I've used them with 87dB sensitive speakers with no issue outside of some ground loop hum in one particular room. The one guy I remember who had an issue with audible hiss was using very high sensitivity speakers (109-110 dB) in a very quiet room; he liked the amps otherwise but just wanted silence...he also searched for a pre-amp that was quieter too (think he went with Benchmark for both, but its been a while).

 

[lovinthehd]

The emotiva is 2 pronged every one of them I've bought from Emotiva is.

If it turns out to be a ground loop how is it fixable?

You can try simply using a cheater plug to see if that's it (3 in, 2 out).

 

[lovinthehd]

When I was researching them I heard mentioned in a couple reviews that you can have noise from the tweeter when they are not playing and this is common for pro amps like this on home theater equipment. This Andrew guy on YouTube was one of the reviews he really spoke highly of these amps which got my attention on them in the first place

Just like he said before I turned down the gains when I'd play something you couldn't hear it but you could if everything was not playing so I just thought that's what it was

Andrew Robinson? Somewhat common complaint of pro amps to have some hiss but precedes class D.

 

[lovinthehd]

Yes I do recalibrate

Hmmmmm a ground loop you say? There plugged into the dedicated 20amp circuit I had put in for them so there not sharing anything but it is more like a hum or a high pitch whine now that you mention it then a hiss. Like you said hard to put it into words

The amps are on top of the rack right now above the Emotiva amp could that be an issue? Here's a pic.

View attachment 28728

Can't really tell from a pic but move the amps onto the floor to test perhaps. I have a pair of 1500s that sit under an avr but with a fairly thick shelf in between....

 

[Danzilla31]

Can't really tell from a pic but move the amps onto the floor to test perhaps. I have a pair of 1500s that sit under an avr but with a fairly thick shelf in between....

Ok good news the dynamics issue highs midrange all resolved when I recalibrated and set the input sensitivity to the .7 instead of 1.4

They sound great every bit as good as the Emotiva. I set the gains like youbdobwhere they won't clip at reference. Which is for me 72 on the Denon. That's plenty loud enough.

When I had them on 1.4 I had to drive them past this point even with calibration and they still sounded flat. And they went higher on the clipping lights. Not anymore. at .7 they came alive yet on the clipping lights I can't get them to push past the input level they don't even flicker into the -20 spot just nice solid input signal.

So one issue is down. Obviously the denon didn't have enough juice in the 1.4 switch on its preouts maybe older versions do this one didn't that's a cool feature on these though being able to switch sensitivity like that for avr's that don't have enough voltage on the preouts

But that hum is still there lovin I think your right it's a ground loop issue. It has to be

I'm going to follow your suggestions and I have a couple of other ideas as well. It's getting late though I'll tinker around and try some things

Do you think a good 20 amp power strip might help? I hate surge protector line conditioner stuff in my experience especially most of the expensive audiophile ones make things worse not better amps and subs go straight into the wall for me maybe I'm wrong that's just my take. But if there's an issue there maybe a good power strip rated for 20amps might help

I'll get back to you guys after I try some things tommorow thanks everyone appreciate the help

 

[Danzilla31]

At least I can't hear the hum when things are playing everything sounds nice and clear

 

[lovinthehd]

Ok good news the dynamics issue highs midrange all resolved when I recalibrated and set the input sensitivity to the .7 instead of 1.4

They sound great every bit as good as the Emotiva. I set the gains like youbdobwhere they won't clip at reference. Which is for me 72 on the Denon. That's plenty loud enough.

When I had them on 1.4 I had to drive them past this point even with calibration and they still sounded flat. And they went higher on the clipping lights. Not anymore. at .7 they came alive yet on the clipping lights I can't get them to push past the input level they don't even flicker into the -20 spot just nice solid input signal.

So one issue is down. Obviously the denon didn't have enough juice in the 1.4 switch on its preouts maybe older versions do this one didn't that's a cool feature on these though being able to switch sensitivity like that for avr's that don't have enough voltage on the preouts

But that hum is still there lovin I think your right it's a ground loop issue. It has to be

I'm going to follow your suggestions and I have a couple of other ideas as well. It's getting late though I'll tinker around and try some things

Do you think a good 20 amp power strip might help? I hate surge protector line conditioner stuff in my experience especially most of the expensive audiophile ones make things worse not better amps and subs go straight into the wall for me maybe I'm wrong that's just my take. But if there's an issue there maybe a good power strip rated for 20amps might help

I'll get back to you guys after I try some things tommorow thanks everyone appreciate the help

Just get some cheater plugs to see if that's the issue. They're not good permanent solutions due added risk.

 

[snakeeyes]

Sensitivity is 88dB on the Ultra Towers.

The amp I keep thinking about is the Outlaw 2200 monoblocks but probably won’t buy until they go on sale again.

 

[TLS Guy]

I think just the standard tweeter hum you get from class d amps. No hissing it goes quiet if I back off the gain a few clicks on the Crowns it's gone you can hear it from 1 or 2 feet away if the gain is all the way up on the Crowns

But when I turn the gain down a few clicks on the Crowns and eliminate the hum and go back and forth between the Crowns and Emotiva there is a noticeable drop in dynamics and midrange presence a little on the highs when the denon is at the same volume level between both amps.

Noticeable to the point I'm wondering if the crown needs to be on the .7 setting instead of 1.4 it's always felt on 1.4 like I've needed to have the denon cranked a little more then Id like to get the same dynamics when using the Crowns I'm getting ready to try it on the .7 setting see if it helps.

On the speakers I don't want to say anything just yet. There was a hiccup when Bjorn's was ordering them they said an in stock issue some crap like that and I don't want to say anything to you guys till I know I'm getting them for sure

I really hope I get em tho kind off fell in love with them

I think you are expecting too much from a cheap industrial amp designed for rock bands. The S/N is not adequate. Also the input trim sensitivity is obviously done on the cheap. It must be a standard old fashioned and cheap input trim. If on the other hand it had an opamp, with the input sensitivity set in the input loop, then S/N would not be effected by the input control.

In a large auditorium with lots of noise and live bands, your issue would not be noticed.

So as I suspect that Crown amps are probably acceptable for sub duty but nothing else in a good domestic system.

You are right about Audyssey though. That is a dreadful quality spoiler and I do not recommend it.

 

[GrimSurfer]

I think just the standard tweeter hum you get from class d amps. No hissing it goes quiet if I back off the gain a few clicks on the Crowns it's gone you can hear it from 1 or 2 feet away if the gain is all the way up on the Crowns

But when I turn the gain down a few clicks on the Crowns and eliminate the hum and go back and forth between the Crowns and Emotiva there is a noticeable drop in dynamics and midrange presence a little on the highs when the denon is at the same volume level between both amps.

Noticeable to the point I'm wondering if the crown needs to be on the .7 setting instead of 1.4 it's always felt on 1.4 like I've needed to have the denon cranked a little more then Id like to get the same dynamics when using the Crowns I'm getting ready to try it on the .7 setting see if it helps.

On the speakers I don't want to say anything just yet. There was a hiccup when Bjorn's was ordering them they said an in stock issue some crap like that and I don't want to say anything to you guys till I know I'm getting them for sure

I really hope I get em tho kind off fell in love with them

Are you using balanced connectors to the speakers?

 

[Out-Of-Phase]

I think you are expecting too much from a cheap industrial amp designed for rock bands. The S/N is not adequate. Also the input trim sensitivity is obviously done on the cheap. It must be a standard old fashioned and cheap input trim. If on the other hand it had an opamp, with the input sensitivity set in the input loop, then S/N would not be effected by the input control.

In a large auditorium with lots of noise and live bands, your issue would not be noticed.

So as I suspect that Crown amps are probably acceptable for sub duty but nothing else in a good domestic system.

You are right about Audyssey though. That is a dreadful quality spoiler and I do not recommend it.

Wow.

I better stop listening to classical music on that thing.

 

[highfigh]

Are you using balanced connectors to the speakers?

WHAT????????????????????

 

[highfigh]

Hum is low frequency noise, inaudible from a tweeter.

 

[GrimSurfer]

Well it is a "pro" amp, right? It does have balanced outputs, doesn't it?

What do you think those things are there for, if not noise rejection?

Crown literature mentions the high magnetic fields in its XLS line. Such fields are a form of EM radiation, which is why Crowns (and most pro gear) have balanced inputs and outputs.

 

[Danzilla31]

Are you using balanced connectors to the speakers?

No it's an avr so unbalanced plan on going to separates just not yet