PSW404 Low Pass Setting

DonnyHardo

I am using a PSW404 sub in a stereo music setup.

Typical wiring, with amp speaker output connected to subwoofer speaker input and speakers connected to subwoofer speaker output. My speakers are decent, large bookshelf, Celef Domestic III. They are pretty "full range" in my opinion.

I have set the "80 Hz / Full Range" switch to Full Range, and the "Low Pass" knob set to the minimum, 60 Hz. Volume knob is set to just under 50%.

My understanding is that this means anything 60 Hz or lower will be handled by the subwoofer, and anything higher will be handled by the speakers.

However I have been playing with test tones available on youtube (I don't know how reliable they are), and when I play an 80 Hz tone, it is clearly still coming out of the subwoofer (and the speakers). I am trying to avoid double handling overlap, where speakers and sub are playing the same sounds. Is this achievable (or desirable)?

I've been getting an occasional unpleasant, harmonic hum when playing certain music. I'm sure placement is also an issue, but putting that aside for now, I just want to understand how the controls work, and how to control what frequencies are handled etc.

Any advice appreciated.

F1nut

The frequency points are not sharp cut offs, rather they are roll off points.

What is the -3dB Hz rating of your speakers?

DonnyHardo

Thanks. That occurred to me after posting. It sounded like I was expecting sharp cut off didn't it. But I have no idea about the -3db Hz rating. They are pretty old. I did some googling and can't find anything about specifications. This is them:

https://canuckaudiomart.com/details/649040938-celef_domestic_iii_super_bookshelf_speakers/images/532528/

Celef became ProAc.

F1nut

Ok, play a 60Hz test tone through the speakers only, then play lower tones until you start to notice the volume level dropping. That will be close to the -3dB point. Let's say they drop at 40Hz, so set the sub crossover at 45Hz for a start. Play with the volume level too. You want to dial it in so that you don't know the sub is on until you mute it or turn it off.

I have add, that is not a good choice for a music sub. It's ported and specs at 32-160 Hz (-3dB). Sealed subs are much better for music.

DonnyHardo

Thanks. 60 is the minimum. With your help I understand it a lot better. I was just worried I was doing something wrong. I am coming to the same conclusion (not good for music). Sometimes it sounds good, but it is a bit hit and miss, and I can't be bothered tweaking it constantly from one recording to the next. Cheers

F1nut

Take a look at Velodyne or Rythmik.

rooftop59

The other issue is that If you want a high pass signal sent to you mains, set that switch to 80hz. This means that a approximately 80hz and above will go to the mains and you can then set the sub at 80hz. But I would also prefer to run the speakers full range. Another method is to skip the test times, set the crossover at its lowest point and the volume at maybe a quarter and then play a tune with really deep bass that you know very well and just play with the setting until it sounds right.

If you are comfortable buying used, a Martin Logan dynamo original can be had on eBay for around $200 if you’re patient, and it’s an excellent sealed sub with a very accurate crossover and the full array of inputs and outputs. And it digs well into the 20s hz range.