Sub crossover point for La Scalas

[sixsigma]

So I decided to deploy a sub with my La Scalas. I went with the Polk PSW505 which is a powered 12-inch sub, great reviews and relatively inexpensive. I am going to be using the speaker/line level inputs as my Yaqin amp doesn't have a pre or sub out. According to https://www.upscaleaudio.com/pages/subwoofer-tips this is not a bad way to go. I do not intend to connect the LS to the speaker-out on the sub, which means I will continue to have full range going to the LS. The sub has a variable crossover point, from 60-120hz. What would you recommend as the sub xo point, given that the LS will continue to receive the full range signal. I've read the LS drop off completely at ~50hz and are weak below 90hz, so I'm thinking 90hz is a good point. I'll experiment but wondered what the community thinks best given your experience and this specific config.  

[JohnA]

Room placement matters.  The closer to walls and corners the lower the effective low roll-off of your La Scalas.  Mine are against the wall sitting on top of a subwoofer and I use 70 Hz.  Audessey chose 40 Hz for my La Scalas in my room(!), but I overruled it.  

 

It is hard to imagine you will not be highly disappointed with one Polk PSW505, or even 4.  I would set the crossover no higher than 60 Hz to reduce the impact of its distortion on your music.  Bass distortion from La Scalas is quite low. 

[jason str]

Mine are not placed in corners and high passed @ 200 Hz with a Second order (12 dB) slope, crossover is between 90-95 Hz in my system using a THTLP horn loaded subwoofer.

[Schu]

My sub is unfortunately direct radiating and manually dialed in by ear to somewhere between 60-80Hz.

I find the direct radiating can easily overpower and muddy the brilliant LF section of the la scala, so dialing it in by ear allows me to taylor the sound to my taste and LP.

[pzannucci]

18 hours ago, sixsigma said:

So I decided to deploy a sub with my La Scalas. I went with the Polk PSW505 which is a powered 12-inch sub, great reviews and relatively inexpensive. I am going to be using the speaker/line level inputs as my Yaqin amp doesn't have a pre or sub out. According to https://www.upscaleaudio.com/pages/subwoofer-tips this is not a bad way to go. I do not intend to connect the LS to the speaker-out on the sub, which means I will continue to have full range going to the LS. The sub has a variable crossover point, from 60-120hz. What would you recommend as the sub xo point, given that the LS will continue to receive the full range signal. I've read the LS drop off completely at ~50hz and are weak below 90hz, so I'm thinking 90hz is a good point. I'll experiment but wondered what the community thinks best given your experience and this specific config.  

From what I have seen with most subwoofers that have speaker level outs, they have a capacitor on the output that will roll off the main speakers.  Do you want to roll off the LaScalas?

The documentation states that you should use the speaker level outputs of the sub for RM series speakers or similar.  Since those are small speakers it is likely that the sub has a crossover in line and most likely starts attenuating the low frequency response at 100hz or so.   You should verify this since the manual for the sub is a little slim.

 

I'd parallel the speakers and sub to the amp for insurance.