Is this how a Subwoofer Crossover is supposed to work?
Wolfie62 wrote: "Looks there is a hardwired inductor blocking output at 50 Hz. Is there?" I speculate that the inductor is the woofer’s voice coil. In general the longer the voice coil (the more turns of wire in it), the higher the inductance. There are construction techniques which minimize voice coil inductance, but they are expensive, and may not be practical at some price points. Duke |
Seeing as how the Willsenton R8 has no pre-amp output and the Starke SW12 has no speaker level input you are going straight from your dac to the subs, correct? Are you controlling the volume level with the dac and just using the R8 as an amp only? What you describe sounds an awful lot like you are using a fixed volume output from your dac. "They are way too loud even with the volume set almost to off". I am willing to bet you are sending a full power signal to the subs and over driving their amps. This will cause all of the problems you are having. |
OK. I have taken the suggestions to measure a single Starke SW12 subwoofer near miked in the middle of the room sitting on a padded footrest which is about the best I can do to take out any factors other than the subwoofer. Just for yucks I also measured a Klipsch R12SW with similar settings. You can see the measurements for the Starke SW12 alone here: https://www.dropbox.com/s/dwpnt5ndcstr3gu/Starke%20SW12%20Crossover%20Settings%20Near%20Field%20Mic.... And here you can see the Klipsch R12SW alone: https://www.dropbox.com/s/b5qb4r9f8xsasiv/Klipsch%20R12SW%20Near%20Field%20Crossover%20Measurements.... These were measured with the Sub hooked up to the DAC with an RCA cable. I did also measure using a balanced/XLR cable which provided exactly the same curves but with 7 dB of gain which explains why I was having trouble getting the volumes low enough with the Starke when I had it running on a balanced XLR input. So oldhvymec nailed that one. Getting subs and main speakers aligned seems to require using the same inputs which sucks because I have to believe all those Y splitters degrade the signal quality? Some observations 1) Boy that Klipsch R12SW is a piece of crap! I didn’t expect it to be good but I certainly didn’t think it was that bad. 2) It is kind of impressive that the Starke is only loses 5 dB from 26 Hz to 17 Hz and has such a flat response out to about 60 Hz depending on the crossover setting. 3) Even though the Klipsch curves are so much worse the crossover seems to be functioning in a fundamentally similar way to the Starke so it could be how I thought crossovers ought to work simply aren’t how subwoofer crossovers are designed. 4) It would be nice to see similar curves for a truly high end Rel sub just to be sure. 5) It looks like the Starke SW12 will be very useful for extending the bass response lower and smoothing any room nodes if I play around with positioning them in the room but only below 60-70 hz. I have crazy peaks and valleys with my Moabs between 50-85 Hz that I’ll have to fix some other way. |
geared4me I use the volume controls on the R8 to get the rough level and then the volume control on the DAC to fine tune. The DAC doesn't have any amplification. The DAC Volume Control only reduces volume. BUT it turns out having the Subs hooked up with the DAC's Balanced Outputs runs about 7 dB hotter than if you hook them up via RCA. So that is where the problem with the sub running too loud probably starts since the R8 only accepts RCA inputs and only has speaker level outputs. |
