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jfine
04-18-2019, 03:25 PM
First of all I don't run my BX63A crossover for the B460 subwoofer like the manual says. I tap off a pre to amp interconnect to run signal to the BX63A. But I don't use the main out of the BX63A back to the main amp, i.e., I don't use the BX63A to intercept the mains, just a signal to it, and signal out to sub amp.

I've read that it's better to run a sub off the speaker outputs of the main amp vs tapping off a pre signal.

If I were to do that, would running lines off the main amp speaker terminals to the BX63A input work just as well?

Thanks in advance.

HCSGuy
04-18-2019, 04:37 PM
Absolutely not. You can't run an amplified out into a preamp input - even though the input is high impedance. There are a few manufacturers that make speaker level to line level convertors, but they're not high quality; they're meant for housewide music systems or car audio. I think REL was the first manufacturer to claim a high level input lets you keep the sound character of your system even through the low frequencies, but as a former REL dealer, we never saw any concrete improvement, and usually could adjust the subwoofer to sound the same with either input, though all the amps we used were conventional solid state amps with neutral sound quality (Parasound, Bryston), so you would probably notice a difference more (possibly worse) with a single ended tube amp, etc. Since I assume the rest of your system is sounding great, I would consider a better crossover or something with room correction or a parametric eq that would let you adapt your system to your room better. Velodyne used to make the SMS-1 that was a subwoofer crossover and room correction/manual EQ in one box, including calibration mics. Pick one up off Ebay and have fun:)

jfine
04-19-2019, 08:43 AM
Makes sense, I just read that some sort of high level input into a sub amp, if available, can be used straight from main amp output, never saw this in action though. Wasn't sure if the BX63 could do this.

Hmm could a crown XLS2000 do this, I could bypass the BX63 and use the crown internal pass filters.

emilime75
04-22-2019, 08:19 PM
No! Many car amplifiers have that capability, but I've never seen a residential or commercial amplifier have this feature.

I'd love to see where you've read this.

jfine
04-27-2019, 04:47 PM
No! Many car amplifiers have that capability, but I've never seen a residential or commercial amplifier have this feature.

I'd love to see where you've read this.

easy to google, high level input,

https://www.upscaleaudio.com/pages/subwoofer-tips

HCSGuy
04-28-2019, 09:37 AM
easy to google, high level input,

https://www.upscaleaudio.com/pages/subwoofer-tips

I think I’ve seen that page before, but I don’t buy it. They’re right that the majority of subwoofers have a speaker level input - I would go farther and say the cheaper the subwoofer, the more likely it is to have speaker level inputs, but the speaker level inputs are there for compatibility, not performance. REL is the only company I know of that has made a gospel out of using it, but I think it’s just a market differentiator for them. Forcing your subwoofer to also produce any hiss, hum, or distortion that your amplifier has doesn’t seem to be a good idea, though I would qualify that by saying the older the equipment, the more likely you are to have issues, or notice a difference. I bet that if we took a new REL subwoofer and connected it to my Bryson stack, we couldn’t tell the difference between speaker and line level inputs.

Btw, don’t know if you’re in the area for the summer, but if you are, you are welcome to swing by and borrow my Velodyne SMS-1 - I’m remodeling a room and won’t need it for 2-3 months. May be fun to play with:)

SEAWOLF97
04-28-2019, 11:22 AM
I I would go farther and say the cheaper the subwoofer, the more likely it is to have speaker level inputs

hmmm , my 2 JBL subs, my M&K and Velodyne all have only speaker level inputs. Does price really have anything to do with it ??? Seems reasonable that line level inputs would not cost more to produce ?? :dont-know:

In fact, I do see a lot of cheapo subs with only line level inputs . ;)

FOR ME, speaker level, subs provide more control .

HCSGuy
04-28-2019, 02:29 PM
hmmm , my 2 JBL subs, my M&K and Velodyne all have only speaker level inputs. Does price really have anything to do with it ??? Seems reasonable that line level inputs would not cost more to produce ?? :dont-know:

In fact, I do see a lot of cheapo subs with only line level inputs . ;)

FOR ME, speaker level, subs provide more control .

Let’s clarify the discussion - Jfine posted about using a speaker level output from a full range amplifier to feed the input of the subwoofer amplifier, or in his case, feeding the BX63A and then his subwoofer amplifier. My statement was pertaining to amplified subwoofers having speaker level inputs, which would make them analogous to his system. It was not meant to compare amplified subwoofers to passive subwoofers. If you are telling me that you have those 4 subwoofers, they are all amplified, and have only speaker level inputs, then your experience is completely different than mine.