[mosawdust]

Would like to add a bit more power to the ST/R's to really see their potential. How would I go about adding an additional amp to power the sub section of these. My source is a Pioneer SX-1250 which I would like to use to power the mids and treble. I know I can use an external amp and bypass the receivers amp but don't want to go that route. Don't know if what I'm asking is possible but you don't know until you ask.

Thanks,
Brian

[John Casler]

Would like to add a bit more power to the ST/R's to really see their potential. How would I go about adding an additional amp to power the sub section of these. My source is a Pioneer SX-1250 which I would like to use to power the mids and treble. I know I can use an external amp and bypass the receivers amp but don't want to go that route. Don't know if what I'm asking is possible but you don't know until you ask.

Thanks,
Brian

Hi Brian,

You may be in luck since not all Receivers of that era have "preamp outs" and it appears yours does.

All you would need to do then is connect the "preamp output L/R" to a relatively powerful integrated amp (or one that has a gain control to match output with the on board amp)

For example the Behringer A-500 would likely drive the woofers reasonably well, is pretty inexpensive and has good power output @ 4 ohms/300wpc.

[flintstone]

You would need a couple of Y-splitter cables, and of course another amp: (another Pioneer sx-1250 would work if you can find one cheap)

Pull the pins that connect the Pioneer preamp to it's amp section (preout/amp in). Insert the splitter at each preout (L+R) at the Pioneer preout jacks.....and feed the split connection back into the Pioneer, and the new amp.


Note: If the two amps do not match (one may play louder at the same voltage)......you would need to be able to turn the louder of the two down, with some sort of volume control.



Dave

[John Casler]

You would need a couple of Y-splitter cables, and of course another amp: (another Pioneer sx-1250 would work if you can find one cheap)

Pull the pins that connect the Pioneer preamp to it's amp section (preout/amp in). Insert the splitter at each preout (L+R) at the Pioneer preout jacks.....and feed the split connection back into the Pioneer, and the new amp.



Dave

Ah, good catch, so the PreOut has a jumper pins to the PreIn.  I was just going by the "list" of ins/outs, but couldn't find a picture of the rear panel to see the jumper.

So yes, then one would need a good quality splitter.

[mosawdust]

Thanks Guys,

So does that mean something like the Behringer wouldn't work because I can't control the volume?

[srb]

So does that mean something like the Behringer wouldn't work because I can't control the volume?

No, that means something like the Behringer would work, because it has level controls.  The split Pre-Out signal is a variable output controlled by the volume knob and you will need an amp with some kind of adjustable level controls to match the gain levels between the Pioneer and the external amplifier, whether on the front panel or rear panel.
 
Steve

[mosawdust]

Bear with me here guys, I seem to be a little slow grasping this.

So if I understand correctly, I would use the Y splitter cables off the Pioneer to the Behringer. Once the volume level is set on that, then both amps volume is then comtrolled by the receiver. Is that right?

[srb]

So if I understand correctly, I would use the Y splitter cables off the Pioneer to the Behringer. Once the volume level is set on that, then both amps volume is then comtrolled by the receiver. Is that right?

That is correct.  Theoretically, if you used the same amplifier for the external amp or one with the exact same gain, you wouldn't need level controls to calibrate the external amp.  But level controls also give you the option of slightly boosting or cutting the volume to the woofer section, as may be dictated by your room or listening tastes, even if that deviates a bit from the design of the speaker.
 
Steve

[mosawdust]

Thank You very much.

[flintstone]

I have a pair of ST/R's that I bought new (1996, I think). With the level controls on the Supertowers, and the level controls on the new amp.........you should be fine.

I used to run my Supertower/R's with an Onkyo receiver and an Onkyo M-504 power amp on the bass.......worked fine.


Dave

[doug s.]

i think your receiver has pre outs & main ins, which means you could actively cross over your main speakers as well - you would run the receiver's pre outs to an active x-over; then run the x-over's low pass to the sub amp(s), and the x-over's high pass back into the main ins of your receiver.  or, if you want a tube amp for the main speakers, you would run the hi pass from the x-over to the tube amp, and the low pass to the the receiver, and power your sub(s) from the receiver's amp.  the x-over will be able to gain match the amps...

doug s.

[John Casler]

i think your receiver has pre outs & main ins, which means you could actively cross over your main speakers as well - you would run the receiver's pre outs to an active x-over; then run the x-over's low pass to the sub amp(s), and the x-over's high pass back into the main ins of your receiver.  or, if you want a tube amp for the main speakers, you would run the hi pass from the x-over to the tube amp, and the low pass to the the receiver, and power your sub(s) from the receiver's amp.  the x-over will be able to gain match the amps...

doug s.

Hi Doug,

Not sure how well an active XO added to the passive would work.  The OPs speakers already have passive XO's in place.  Have you employed this before to a good advantage?

[doug s.]

Hi Doug,

Not sure how well an active XO added to the passive would work.  The OPs speakers already have passive XO's in place.  Have you employed this before to a good advantage?

john, i think you misunderstood me.  i am not recommending bi-amping the main speakers by using an active x-over between the main speaker drivers.  i am recommending using an active x-over between subwoofers and main speakers, in the receiver's pre-out/main-in loop.  set the active x-over at, say, 80hz, and use either the receiver's amp as sub(s) amp w/a tube amp for the mains; or a sub amp for the sub(s) and the receiver's amp for the mains...

if the o.p wants to use the "subs" built in to the st/r's, instead of getting additional subs, i would recommend going inside the speakers, and disabling the x-over between the woofer and midwoofers...

doug s.

[doug s.]

actually, john, if the passive between the "sub" and the midwoofers is a rather shallow slope, and a simple straight crossover w/o any overlap or differing walues, you could likely use an outboard x-over w/little or no ill-effects, if you set the x-over point at the same walue as the passive, and ran it much steeper - say 48db/octave or more, which should be possible w/a dsp x-over like the behringer...

doug s.

[mosawdust]

Thanks for spending the time for the information guys. Its much appreciated. Now I have to decide what's going to be the best way to do this for me. I really don't want to to make this complicated because this is why I sold off my old system and took this route. The wife could never figure out what did what and which buttons to push.  I just want to have enough power to be able to crank it up when I want to. The pioneer does a darn good job but I worry about clipping the speakers.

Brian

[doug s.]

Thanks for spending the time for the information guys. Its much appreciated. Now I have to decide what's going to be the best way to do this for me. I really don't want to to make this complicated because this is why I sold off my old system and took this route. The wife could never figure out what did what and which buttons to push.  I just want to have enough power to be able to crank it up when I want to. The pioneer does a darn good job but I worry about clipping the speakers.

Brian

if you were to bi-amp - either w/outboard subs, or using the "subs" built-in to the speakers, once everything is set up and dialed in, it would be completely transparent to a user - all you would do is use the pioneer as you presently use it...

doug s.

[Mark Korda]

Hi Brian,all those guys with great info might have missed something.Most sub woofers out there have built in amps,most often in the back.I built a sub from Parts Express components.At first I used bi-amping with a little Dyna-35 for the upper range,crossover,and a Marantz 500,mono 125 watt solid state amp.I then bought from Parts Express a BASH sub amp from Canada,for about 100 bucks,300 watts.I cut a hole in the sub and installed it.It has a built in crossover,output level,and frequency selection.I could eliminate my crossover and Marantz now,and I used that Y cable connection idea.With 2 cables coming from my cd player to 2 Y cables,1 Y cable from the cd to Pioneer receiver,and the other Y cable to the Bash sub amp,no speaker wires needed to the sub,just the Y cable.The downside is for me,I can only play my sub when my landlord brings his kids to the parents,X-mas time ect.....cause I can scare the luvin beJesus out of them living across the hall.....good luck Bri...Mark Korda

[doug s.]

Hi Brian,all those guys with great info might have missed something.Most sub woofers out there have built in amps,most often in the back.I built a sub from Parts Express components.At first I used bi-amping with a little Dyna-35 for the upper range,crossover,and a Marantz 500,mono 125 watt solid state amp.I then bought from Parts Express a BASH sub amp from Canada,for about 100 bucks,300 watts.I cut a hole in the sub and installed it.It has a built in crossover,output level,and frequency selection.I could eliminate my crossover and Marantz now,and I used that Y cable connection idea.With 2 cables coming from my cd player to 2 Y cables,1 Y cable from the cd to Pioneer receiver,and the other Y cable to the Bash sub amp,no speaker wires needed to the sub,just the Y cable.The downside is for me,I can only play my sub when my landlord brings his kids to the parents,X-mas time ect.....cause I can scare the luvin beJesus out of them living across the hall.....good luck Bri...Mark Korda

even if i were to use powered subs w/built-in x-overs, (and i have used them), i would bypass their built-in x-over electronics by setting them to their highest setting, and then use a quality outboard active x-over set an octave (or more) lower.  a good outboard active x-over will be much better than any built-in x-over in a plate amp, espicially critical for when you want to high-pass your main speakers.

ymmv,

doug s.

[John Casler]

Hi Brian,all those guys with great info might have missed something.Most sub woofers out there have built in amps,most often in the back.I built a sub from Parts Express components.At first I used bi-amping with a little Dyna-35 for the upper range,crossover,and a Marantz 500,mono 125 watt solid state amp.I then bought from Parts Express a BASH sub amp from Canada,for about 100 bucks,300 watts.I cut a hole in the sub and installed it.It has a built in crossover,output level,and frequency selection.I could eliminate my crossover and Marantz now,and I used that Y cable connection idea.With 2 cables coming from my cd player to 2 Y cables,1 Y cable from the cd to Pioneer receiver,and the other Y cable to the Bash sub amp,no speaker wires needed to the sub,just the Y cable.The downside is for me,I can only play my sub when my landlord brings his kids to the parents,X-mas time ect.....cause I can scare the luvin beJesus out of them living across the hall.....good luck Bri...Mark Korda

I think the title of the thread might cause a little confusion.

Brian, is looking to add an amp (thereby biamping) to the woofer section of his ST/R's, and the woofer section is quite similar to the LARGER Sub.

So he is not actually looking to add a SUB, but wondering whether a SUB AMP would power his WOOFER section of his mains.

[mosawdust]

I think the title of the thread might cause a little confusion.

Brian, is looking to add an amp (thereby biamping) to the woofer section of his ST/R's, and the woofer section is quite similar to the LARGER Sub.

So he is not actually looking to add a SUB, but wondering whether a SUB AMP would power his WOOFER section of his mains.

John is correct. With the new xover in these now Big B has eliminated the toggle switch and the 12" is no longer tied in with the mid xover and each on their own set of binding posts. Basically I have the larger sub and satellites just in the same cabinet.

Its looking like the Behringer or a QSC may still be the best solution.
There is a QSC PLX 3002 locally that I could probably snag for 300.00. Any opinions on this?