Sub woofer input connection

butchbass · 5067

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Offline butchbass

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on: February 05, 2015, 03:41:38 PM
Is there any benefit in using the pre amp outputs to input to the subwoofer instead of the power amp speaker outputs? Depending on the recording I find it necessary at times for my taste to adjust the subwoofer volume. I was thinking of getting the Dayton desk top subwoofer amp so I can adjust it from my listening position. I would install banana jacks on the current plate amp on the Dungeness and connect the speaker writes to the jacks bypassing the plate amp. I currently have the FPIII and Paramours.

Thanks
Butch

Butch Gross
Stereomour II/  Blumenstein Orcas, Dungenes/Schiit Bifrost Multibit/Amarra


Offline Paul Joppa

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Reply #1 on: February 05, 2015, 04:40:57 PM
It's a balance between competing virtues.

Much of the character of the fullrange amp carries into the sub when it is driver from the speaker outputs. Technically that would include the distortion spectrum and the frequency response bumps from the moderate damping factor of SETs; I'm confident there are other effects we just don't know about yet. Result - better integration.

With preamp output, you get rid of any hum or noise introduced in the power amp, and the frequency response is smoother. Result - cleaner, more extended bass.

What can I say? Your ears, your choice.

Paul Joppa


Offline Gerry E.

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Reply #2 on: February 06, 2015, 04:37:12 AM
Is there any benefit in using the pre amp outputs to input to the subwoofer instead of the power amp speaker outputs? Butch

Pierre Sprey from Mapleshade insists that subwoofer input should be taken from amplifier output.  Based on that, I've tried it both ways over long periods of time.  Despite Pierre's recommendation, I prefer taking them from the preamp output.  IOW, I followed Paul's advice and let my ears decide.

Gerry             



Offline corndog71

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Reply #3 on: February 06, 2015, 10:06:12 AM
Speaker level inputs typically insert about a 100uF electrolytic cap into the signal path which may be the worst possible way to add a high pass filter and will affect the signal to the main speakers.   But as always, it's your choice.

The world was made for those not cursed with self-awareness.

Rob


Offline Clark B.

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Reply #4 on: February 06, 2015, 12:51:24 PM
Speaker level inputs typically insert about a 100uF electrolytic cap into the signal path which may be the worst possible way to add a high pass filter and will affect the signal to the main speakers.   But as always, it's your choice.

Does not apply in the case of our method of integration for the Blumenstein Audio Dungeness subwoofer.

For speaker wire hookup, the lengths of speaker wire used for the subwoofer amplifier's inputs is simply doubled up (biwired) at either the binding posts of the fullrange speaker or alternatively at the binding posts of your stereo amplifier.  Either place does not affect the sound quality.  As well, it can be an assymetric hookup location in this respect without affecting sound quality, which is convenient as well. 

The quality of this speaker wire is essentially inaudible as well, which is also convinient because the quality of the typically long length of RCA cable for the inputs would be audible.  I recommend cheap high gauge wire that comes on a roll.  This set of speaker wires only goes into the "from amplifier" section of inputs of the subwoofer amp, (and does not come back out of the "to speaker" outputs, which keeps those nasty electrolytic caps from being engaged).  Its a pure and simple method of hookup, and only bleeds a tiny amount of signal from a Power Amp, rather than drawing 50% of the output of a Pre Amp.

RCA hookups can have some sonic advantages in certain cases, however, and in the case of Bottlehead products, RCA subwoofer inputs work very well!  So in general, I feel that speaker level vs. RCA hookups for a subwoofer will all depend on the makeup of the rest of your system.  While speaker wire inputs are universally compatible for prettymuch any power amplifer, some Bottlehead Pre-amps have a provision for dual RCA outputs ((one set to the stereo power amp, one set to the subwoofer(s). And they sound great hooked up that way with my speakers/subs!  I like to match lengths (a less practical recommendation) and types/brands (a more practical recommendation) for the quad of RCA cables coming from the back of the pre amp.

Hope those explainations and tips help!

Best,

Clark
 
« Last Edit: February 06, 2015, 01:24:03 PM by Clark B. »



Offline butchbass

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Reply #5 on: February 06, 2015, 05:25:40 PM
Dang, I was hoping for black and white answer on the "best" way but it looks like my old ears will have to determine the best way for
my listening pleasure which won't be a problem. That is what this hobby is about.
Thanks for the feedback,

Butch

Butch Gross
Stereomour II/  Blumenstein Orcas, Dungenes/Schiit Bifrost Multibit/Amarra