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DAC to Subwoofer output input voltage problem.

jst

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I use DAC Topping D10s :
Screenshot_494.jpg


And I use Wharfedale SW250 Subwoofer
Screenshot_493.jpg


I usually use Cambridge Audio Azur 640a that comes with PRE OUT, that I can use for my active subwoofer, but now I prefer using Aiyima A07 , but it doesn't have preout (since it's just amp, not integrated amp).

The problem is , if I use output from DAC, the bass on the subwoofer will be distorted. Must be because of the high gain from 2v while sw250 input sensitivity is only 325mv or cmiiw. My Azur 640a is 380mv from the manual, and I read that rca line level is 0.5v, so it's more or less that much. But Topping d10s is 2v.

I've googled around and seems like not so many ppl have this problem. I found one on reddit and someone suggested using Attenuator.

For car audio we can use High-low converter, I can probably use that too but will it affect the output to speaker ? But seems like it also need dc power.

If anyone ever had this problem, what's your solution ? I can just use my Azur 640a but I'm curious whether there's more bulls eye solution to this, like lowering rca voltage to be line level. What's the device called ? for home audio. All I have is a pre-out.

I have tried adding tube preamp fx-audio tube-01 and split the output to amp and sub, it still has the problem.
 
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Blumlein 88

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This in line attenuator would drop the voltage of the Topping from 2 volts to 500 mv. I think they are expensive for what they do. You can make something similar yourself. You also might want a variable attenuator so you can get the sub output the way you want unless it has its own level control in which case this 12 db attenuator might get you close enough.


Might help to draw a little diagram of how you connect and use the Topping in your system.

Something like this would work too, but I've not used this particular brand.
 
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jst

jst

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Thx. I think I found one similar locally for ~$5 , it seems passive, no jack for dc or anything.
17 ppl bought it, so I'm not alone, hahah.

Screenshot_496.jpg
Screenshot_497.jpg
 
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jst

jst

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That should work too, but is it also a crossover for the sub side? You might not want that, but could always use the other side.
I'll try it later when it arrives, it's foreign merchant in local online shop, probably will take 1 or 2 weeks.
It's for subwoofer I hope it won't double low filter or make the sound weird, hope I can tamper with it to disable the left one if it does make it weird.
 
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jst

jst

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I can't edit my old post it seems.

Just want to update that the item I bought has arrived but it doesn't work as expected. It probably able to weaken the signal but not to a point that's acceptable by wharfedale sw250 because the distorted sound seems less. However, I can make it gone by using the frequency knob, but the bass is also much weaker and doesn't sound good, a pre-out from an integrated amp is still the best. (using ca 640a.v2)

I wonder if that's common in subwoofer amplifier or this wharfedale sw250 is oddly designed that it cannot accept input from DAC, while an amplifier can seem to accept whatever signal is sent to it be it from dac, phones, etc. Isn't a subwoofer basically also a power amplifier with added filters for frequency ?

Anyway, I have also tried pre-out from a super old amp sansui au555a and it's also distorted on wharfedale sw250, seems like it's just passing whatever is fed to it. The preout works fine using Aiyima A07.
Screenshot_501.jpg
 
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Willem

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Depending on where you are, Harrison Labs do cheap inline attenuators that should do the job.
 
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DanielT

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Wait now. Step by step.We start with the basics.
1. Has your subwoffer ever worked properly?

2. IF it has worked well, what signal source did you input to the subwoofer? From which device then?

Is it one I attached to the pictures you have? If so your sub is active, that is, it has a built-in amplifier
 

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raindance

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The subwoofer input sensitivity is totally normal. That spec is with the volume pot turned all the way up. Typically you'd never run it above the 9-11 o clock range where it'll easily decrease sensitivity into the 2 volts range. Plus the DAC only outputs 2 volts at full volume with source data that is recorded at 0dB. If you're running the DAC at full volume and the subwoofer at full volume, then you have more issues than you think. You're not understanding the specs and the specs are likely not your problem.
 
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jst

jst

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Wait now. Step by step.We start with the basics.
1. Has your subwoffer ever worked properly?

2. IF it has worked well, what signal source did you input to the subwoofer? From which device then?

Is it one I attached to the pictures you have? If so your sub is active, that is, it has a built-in amplifier
1. Of course, like I said earlier it works fine when using Cambridge Audio Azur 640a v2 from pre-out, other than that, nothing works. Sansui Pre out, directly from DAC, using the newly bought bass regulator.

2. It is from Topping D10s DAC, I split it using audio video selector with 4 inputs and 2 outputs, 1 goes to Aiyima A07, 1 goes to subwoofer.

Yes, that's the one I have, and I can recognize active/passive speakers/subwoofer. Now that you posted the picture, I just realized I never checked the backpanel for like maybe 8 years lol. I put it in a location that's kinda hard to access with all the stuffs around it. All I have coming out from it is RCA cable for all these years. Damn It actually has that high input from speaker out that I can probably use from Aiyima A07 hahah. Thx for posting that pic as a reminder.

Guess I'll just try the speaker output level that's on the backpanel of this sub when i have the time to clean up and access the backpanel of the sub.


Screenshot_502.jpg
 
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DanielT

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It was not my intention to get you annoyed but maybe it paid off? Sometimes the solution may be easier than you think, or do not think about. I'm the same, sometimes I miss things that I actually have in front of my eyes. So to speak.:)
 
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jst

jst

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It was not my intention to get you annoyed but maybe it paid off? Sometimes the solution may be easier than you think, or do not think about. I'm the same, sometimes I miss things that I actually have in front of my eyes. So to speak.:)
Nah, I'm not annoyed, not at all. And yeah it is, hahah.
 
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jst

jst

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Sorry for bumping the thread once again when the problem is fixed but I have to do it justice for this bass regulator which is working fine now, and I cannot edit my last post. (Usually I can edit all my posts even the old ones in other forums)

After trying the bass regulator once again, it's working great now, seems like I forgot to turn off my pc's equalizer with a lot of bass boost the other day and the digital volume on the subwoofer needs to be lowered from my usual setting, usually 80 when using preout from integrated amp, now it's 50 using this bass regulator so the signal is weakened but it's still a bit high than usual, but not that high to produce distortion unless I boosted it via eq.

Thanks to Blumlein 88 and DanieIT for the solutions, and others for the input.
 
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