Pre-amp voltage out vs clipping, etc.

[Marvel]

I have a nice little Windows program the will do h-pad and t-pad attenuators, showing the schematic and part values. Not that they are complex, but I have wired them into cables and put heat shrink over them. Quarter watt resistors don't take up much room...

 

Bruce

 

[WMcD]

My preliminary analysis is that I've made a fool of myself by typing without knowing all the facts.  More later.

WMcD

[Emile]

1 minute ago, WMcD said:

My preliminary analysis is that I've made a fool of myself by typing without knowing all the facts

Haha ... do that all the time here  

[Emile]

37 minutes ago, Marvel said:

I have a nice little Windows program the will do h-pad and t-pad attenuators

Bruce,

Thanks ... may have to tap your expertise  

[MenloBob]

On 3/14/2019 at 3:05 PM, Emile said:

OK; ordered the Crown XLS 2502   (actually awaiting approval of my offer ... was OK'd last week  ).  If I do not like it, I've got @babadono's address and number

Add-on ... ordered and paid   

 

So where are you at with this Emile? I have my 510s now and have them sounding great with a minidsp OpenDRC 2x8 as the crossover and eq. It’s pretty apparent to me that your problems are entirely gain related with the bottom end minidsp. I’ve got a couple of suggestions.

 

1. Upgrade to the minidsp 2x4HD. It’s better in so many ways, but most importantly it has 2V analog input and output. You’re gonna want the extra output voltage to drive your pro amp. Also the HD has more SNR.

 

2. Get an attenuator to balance the output voltage from your preamp into the dsp. I’m using this one: https://www.amazon.com/dp/B07GRLV7XG. There are also a few cheaper options, but make sure you pick one with a high quality potentiometer.

 

3. Disconnect the outputs of the dsp and connect the attenuator between your preamp and the dsp input. Open the dsp control program and connect with the usb. Set the input gain to zero. Play a loud rock cd that has pretty uniform loudness (or input a 0db pink noise signal if you have that capability.)  Set your preamp volume at 75%. Adjust the attenuator knob until the input meter display on the dsp control program is peaking at 0db. Now you have the output voltage range from 0 to 3/4 turn on your pre mapped to the unclipped input range of your dsp.

 

4. Once the input gain is right you can adjust the gains on each of your amps to balance the output between the top and bottom. Rew and your calibration mic can help you get this exact.

 

5. There’s a PDF file on klipsch.com for the KP-904 that has Roy’s suggested eq settings for the 510. These are pretty simple to input into the dsp.

 

This should get you really close to the sound you’re expecting based on your passive 904s. Further tweaking can be accomplished by following Chris A’s instructions with REW.

Let me know how else I can help. 

[Emile]

9 hours ago, MenloBob said:

So where are you at with this Emile?

Bob, thanks a lot for the great suggestions!  

 

Haha ... got delayed a bit   Got a new knee and finally (6 weeks  ) am starting to walk without a walker or cane   Think it will be another week or so before I fully can start "playing" again  

 

Many thanks, Emile

[Coytee]

19 minutes ago, Emile said:

Think it will be another week or so before I fully can start "playing" again  

 

Didn't know  you played soccer....  call me impressed!!

 

[MenloBob]

1 hour ago, Emile said:

Got a new knee and finally (6 weeks  ) am starting to walk without a walker or cane 

 

Let me know when you’re ready and I’m happy to help you get this working. The K510 is a magic piece of kit for the size.

[Emile]

1 hour ago, MenloBob said:

Let me know when you’re ready and I’m happy to help you get this working. The K510 is a magic piece of kit for the size.

Bob, Thanks   Yes; love my 904/510 set. That's why I got another pair of 510's ... tried to match them with Forte's but they just overpower those.  So; got a set of JBL 18" pro woofers to try with them next