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Discussion Starter · #1 ·
I'm working on a home theater system which will have two passive 8-ohm in wall subwoofers. Being that the tuner I'm planning to go with (Sony DG920) only has a pre-amplifier for the subwoofer I'll need an external amp to power these subs. The subs can each handle 100W, so I'm looking in the realm of a 200W amp to drive these. Currently, the two models I've seen which best fit the bill are the AudioSource AMP 100 and the Onkyo M282. Both are 200W stereo amps. The way I see wiring this is to use a Y-cable to drive both channels from the subwoofer preamp output.


Is this the best option? The AudioSource amp mentions bridging to run a single channel at higher power than the two separate channels combined. On top of this, the AudioSource amp has the ability to connect to two sets of speakers with front switches to select one, the other, or (in some literature) both. If it is possible to run both speakers simultaneously, it should be possible to bridge the amp and split the output power to the two speakers.


I'd really appreciate hearing what others have done for in wall subwoofers. Perhaps someone has a better amp recommendation for a setup like I'm trying to achieve.


Thanks!
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by Knucklehead90 /forum/post/15467312


You would be much better off with an amp made for a subwoofer. You wouldn't use a sub amp to drive your main speakers, would you?

http://www.parts-express.com/wizards...TOKEN=98310037

I saw the plate amps before (that page, actually), but those are designed to mount into a cabinet. I'm looking for something which can free stand on a component shelf. I believe that AudioSource makes a sub-amp as well..AMP210SUB?


This is an area where I fully admit to not being strong. Are "sub amps" built to respond better in the lower frequency range than a standard amp? If so , are there some good component form factor sub amps out there?


By the way, the speakers themselves are AudioSource AS10SW in-wall subwoofers which will be mounted about 15' apart on the front wall of the theater area.


Thanks again.
 

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Quote:
Originally Posted by StuffOfInterest /forum/post/15469119


I saw the plate amps before (that page, actually), but those are designed to mount into a cabinet. I'm looking for something which can free stand on a component shelf. I believe that AudioSource makes a sub-amp as well..AMP210SUB?


This is an area where I fully admit to not being strong. Are "sub amps" built to respond better in the lower frequency range than a standard amp? If so , are there some good component form factor sub amps out there?


By the way, the speakers themselves are AudioSource AS10SW in-wall subwoofers which will be mounted about 15' apart on the front wall of the theater area.


Thanks again.

You are correct on the model number. It is a 200W 8ohm amp made for the sub with xover controls on the front. It looks nice! I have a very old NHT MA-1A monaural 80W external amp and was looking for options on just the amp unit.


Amazon has it for $299 regular $649. This is further down the road for me but on my list. I have an emotiva amp coming for my lrc today and know my sub is about to be underpowered I think?



Let us know if you buy this and how your system is setup and stuff, what kind of bargain you got!
 

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Discussion Starter · #5 ·
Due to cost, I'm probably going to start out with an AMP100. From the specs, it has a frequency response range down as low (actually a bit lower) than the AS10SW speakers. Also, it will be driven from a specific subwoofer pre-out on the tuner, so I shouldn't have crossover issues to deal with. Plus, it can be had for only $90.


If I'm not happy with the sound quality I can either put a second AMP100 in (pushing me to 300W total power in bridge mode) to increase power or change over to an AMPSUB210 if I see any distortion issues.


I'm not looking to blow walls apart or cause the neighbors to think we are having an earthquake, so two subs in the corner of the room running 50W each should give me enough thump for movies.


Just noticed that there is a separate forum for subwoofers . Guess that might have been a more appropriate place to ask.


Thanks for the information and suggestions.
 

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Quote:
Originally Posted by StuffOfInterest /forum/post/15473251


Due to cost, I'm probably going to start out with an AMP100. From the specs, it has a frequency response range down as low (actually a bit lower) than the AS10SW speakers. Also, it will be driven from a specific subwoofer pre-out on the tuner, so I shouldn't have crossover issues to deal with. Plus, it can be had for only $90.


If I'm not happy with the sound quality I can either put a second AMP100 in (pushing me to 300W total power in bridge mode) to increase power or change over to an AMPSUB210 if I see any distortion issues.


I'm not looking to blow walls apart or cause the neighbors to think we are having an earthquake, so two subs in the corner of the room running 50W each should give me enough thump for movies.


Just noticed that there is a separate forum for subwoofers . Guess that might have been a more appropriate place to ask.


Thanks for the information and suggestions.

Does your AVR allow you to set the crossover frequency to send the sub? You will probably want to make sure nothing above 80Hz is sent to the sub. Do you have large or small fronts? I have large fronts and have my LFE+main and crossover at 40Hz. You will want to make sure whatever you do that you do not send full range signal to your sub. Okay?
 

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Discussion Starter · #7 ·

Quote:
Originally Posted by sticknstones /forum/post/15473778


Does your AVR allow you to set the crossover frequency to send the sub? You will probably want to make sure nothing above 80Hz is sent to the sub. Do you have large or small fronts? I have large fronts and have my LFE+main and crossover at 40Hz. You will want to make sure whatever you do that you do not send full range signal to your sub. Okay?

The manual is vague, but I believe the Sony STR-DG920 will handle it. They don't reference a crossover frequency but do refer to a "bass redirect function" when speakers are labeled as being "small". Also, where it refers to a powered subwoofer, the manual recommends setting the crossover frequency to max. This too would indicate that the tuner is managing the crossover function and sending only the low bass sounds to the subwoofer.


My fronts are actually 3-element inwall speakers. I'll need to check the crossover points on those. It could be that the bass element will end up not being used at all when the sub is on or peraps it will only carry the high end of the lower frequencies.


Oops, hold on, just found one more thing in the back. It looks like the crossover frequency can be set for each speaker. The defaults are to crossover at 120Hz, but the value can be adjusted from between 40 and 200. The AS10SW has a response range of 40 to 200 Hz as well, so I should be in good shape if I'm reading all this correctly!
 

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Quote:
Originally Posted by StuffOfInterest /forum/post/15474801


The manual is vague, but I believe the Sony STR-DG920 will handle it. They don't reference a crossover frequency but do refer to a "bass redirect function" when speakers are labeled as being "small". Also, where it refers to a powered subwoofer, the manual recommends setting the crossover frequency to max. This too would indicate that the tuner is managing the crossover function and sending only the low bass sounds to the subwoofer.


My fronts are actually 3-element inwall speakers. I'll need to check the crossover points on those. It could be that the bass element will end up not being used at all when the sub is on or peraps it will only carry the high end of the lower frequencies.


Oops, hold on, just found one more thing in the back. It looks like the crossover frequency can be set for each speaker. The defaults are to crossover at 120Hz, but the value can be adjusted from between 40 and 200. The AS10SW has a response range of 40 to 200 Hz as well, so I should be in good shape if I'm reading all this correctly!

Yes, I think you have a handle on it. I think the standard on most systems is if you mark your speakers large for the fronts then you can send full bass to them + additional signals to the sub and at whatever frequency you want using the LFE+Main option. If you select small for the fronts then you do not see the LFE+Main. That is just for the LR settings and then you have separate option on the sub itself and it sounds like Sony has those options for you so great! THX has a standard of 80Hz and that is the default for most units.


Enjoy and take care!
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by sticknstones /forum/post/15475572


Yes, I think you have a handle on it. I think the standard on most systems is if you mark your speakers large for the fronts then you can send full bass to them + additional signals to the sub and at whatever frequency you want using the LFE+Main option. If you select small for the fronts then you do not see the LFE+Main. That is just for the LR settings and then you have separate option on the sub itself and it sounds like Sony has those options for you so great! THX has a standard of 80Hz and that is the default for most units.


Enjoy and take care!

Thanks! The pointers and questions helped me to find just the information I was looking for. Now, if the basement remodel is ever finished, the nine speaker home theater can finally come to life.
 

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Discussion Starter · #10 ·
Wanted to close an old loop in case anyone tries to use this thread for advice in the future. I ended up using the AudioSource AMP100 to drive my two passive subwoofers. Bad choice. The AMP100 has a relay which clicks every time the amp is engaged. Being that low frequency effects are not always present the amp is giving a very audible click every time there is a sound effect and then again a second after the effect is over. This clicking is very loud and distracting. I'd highly recomming finding a differerent amp if anyone wants to drive passive subwoofers. I'm going to to have to try to find a replacment for this myself when time permits.
 

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Quote:
Originally Posted by StuffOfInterest /forum/post/19290961


Wanted to close an old loop in case anyone tries to use this thread for advice in the future. I ended up using the AudioSource AMP100 to drive my two passive subwoofers. Bad choice. The AMP100 has a relay which clicks every time the amp is engaged. Being that low frequency effects are not always present the amp is giving a very audible click every time there is a sound effect and then again a second after the effect is over. This clicking is very loud and distracting. I'd highly recomming finding a differerent amp if anyone wants to drive passive subwoofers. I'm going to to have to try to find a replacment for this myself when time permits.

Or you might take the AMP100 out of the "AUTO" Signal-Sensing Mode (and into "NORMAL") then switch it ON/OFF at the same time as your AVR using some kind of 'smart strip'.
 

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Quote:
Originally Posted by StuffOfInterest /forum/post/19295431


Hi. Checked for that almost a year ago. It is in the "NORMAL" position -- switch to the left . I use a smart power strip to turn the amp on and off based on the television.

And you are sure your LFE source is connected to Line Input 2 and NOT to Line Input 1...?
 

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Discussion Starter · #14 ·

Quote:
Originally Posted by SoundChex /forum/post/19296068


And you are sure your LFE source is connected to Line Input 2 and NOT to Line Input 1...?

Actually, I'm pretty sure it is connected to Input 1 (not at home right now to check). Hmm, do you think the relay could actually be the priority selection switch from input 2 to input 1?
 

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Discussion Starter · #15 ·
After a week with the subwoofer signal connected to Input 2 I haven't heard a single click in the amp. Thank you very much for the good catch regarding priority on the inputs. Looks like the AudioSource AMP100 isn't too bad after all as long as you wire it correctly!
 
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