Review and Measurements of Crown XLS 1502 Amp

[calvados.boulard]

Anyone got a link to the service manual for any of this XLS range?
Tried looking everywhere for it - cant find it.

I'm not sure about a service manual, but the user manual is on the Crown website.

 

[JeffGB]

I haven't been able to obtain an actual service manual, but I did once find a document that included scematics as well as operation theory etc. It was very interesting but I'm afraid I don't have a link to wherever I saw it. It discusses some of the differences between models, like the xls 1000 or 1002 uses a builtin DAC in it's propietary chip, but the higher models like xls 1500 used a different external chip the DA the cirrus logic cs4272 . Ok, I just found a link to the document but it's showing as not secure. I went to it and it seems fine, but the choice is yours. I will PM you the link.

 

[calvados.boulard]

I haven't been able to obtain an actual service manual, but I did once find a document that included scematics as well as operation theory etc. It was very interesting but I'm afraid I don't have a link to wherever I saw it. It discusses some of the differences between models, like the xls 1000 or 1002 uses a builtin DAC in it's propietary chip, but the higher models like xls 1500 used a different external chip the DA the cirrus logic cs4272 . Ok, I just found a link to the document but it's showing as not secure. I went to it and it seems fine, but the choice is yours. I will PM you the link.

Could you PM me as well please?

 

[theeld]

Running into some oddness regarding function of the lowpass crossover operation. Specs indicate a 24db/octave cutoff for the given lowpass frequency. In reality via ear/observation I seem to have to set quite low (around 100hz) as anything above that am hearing noticeable "voice" frequencies present. I ran a tone generated sine through to double check and the attenuation is just not matching up as I would expect. Example I set cross over via amp to 120hz and run 200 hz sine wave and alot of audible volume coming through at 200hz. The setting does seem to be "working" as the lower I set the cross over the lesser the 200hz volume, but does not seem to be a "sharp" cutoff at all.

 

[john61ct]

There are plenty of other xovers to try, some very inexpensive.

 

[theeld]

There are plenty of other xovers to try, some very inexpensive.

The xover I am concerned with in this case is that of the DSP Lowpass inherit in this amp (XLS 1502).

 

[john61ct]

I just meant bypassing that if it is so wonky. Or carry on, sorry if that was unhelpful

 

[rvsixer]

Running into some oddness regarding function of the lowpass crossover operation. Specs indicate a 24db/octave cutoff for the given lowpass frequency. In reality via ear/observation I seem to have to set quite low (around 100hz) as anything above that am hearing noticeable "voice" frequencies present. I ran a tone generated sine through to double check and the attenuation is just not matching up as I would expect. Example I set cross over via amp to 120hz and run 200 hz sine wave and alot of audible volume coming through at 200hz. The setting does seem to be "working" as the lower I set the cross over the lesser the 200hz volume, but does not seem to be a "sharp" cutoff at all.

I am using amps for low passed subs, and confirmed via measurements the internal DSP filters work as expected upon initial setup (have since handed off final sub integration to room correction algo).

First thing that comes to mind in your case is to make sure your DSP routing and associated input/outputs are correct. Second thing that comes to mind, "voices" can extend lower than 100Hz so not sure that is a good test.
Personally I would just sweep measure to confirm the filtering, not rely on voices and ears.