adding/replacing HTIB sub help? (1 Viewer)

HI,
I want to know if I can replace my passive non-powered subwoofer that is a part of my HTIB with a powered active subwoofer? I have been looking for hours and hours but could not get a definitive answer. I understand that the preferred method would be to ditch the HTIB and replace the entire system built from scratch with a separate receiver and speakers.
I have a Sony BDV-E870, and would like to replace the supplied subwoofer with a Klipsch SW-110 powered subwoofer. I have the opportunity to purchase this sub for a great deal as an open box item and would like to be able to add/replace it to my home theatre system for some extra bass.
I understand that this cannot be done the traditional way as my receiver does not have any extra audio output jacks other than the ones used to supply power to the included speakers (5 surround and 1 sub with special connectors). I was wondering if I could splice speaker wires from my sub output connection that is going to the passive sub and connect it to one of the inputs, either left or right, on the active sub?
This is what the back of my receiver looks like ( http://www.trustedreviews.com/Sony-BDV-E870_Surround-Sound-System_review_setup-and-operation_Page-2 )
This is sub I want to add/replace into my system ( http://www.klipsch.com/sw-110-subwoofer )
I could be completely wrong, but I was thinking if I splice into the wires from the sub output of my receiver, and connect them to the powered subwoofer, that it may work since they would be supplying an audio signal to the powered sub, while not requiring any additional draw of power from the receiver since the Klipsch sub is a self-sufficient powered subwoofer.
Any help would be greatly appreciated. Thank you in advance.

I don't see any reason that would not work. If I were you though I would take the sub woofer out wire from the receiver and make a "Y" . Basically splice the one wire into two so you can connect a split to each of your high level inputs (Red & Black screw terminals) on your sub. If you just connect one you will only be using half of the sub woofer's amplifier. It should totally work.

gartronics said:

Basically splice the one wire into two so you can connect a split to each of your high level inputs (Red & Black screw terminals) on your sub. If you just connect one you will only be using half of the sub woofer's amplifier.

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That is incorrect information. Plate amps have a circuit board that sums the inputs right after the connectors. It has been proven that you can get full RMS power from the sub amp with only one connector used.
Sometimes a Y adapter is used to keep the amp from shutting down during low volume listening sessions but even that can be remedied by adjusting the LFE output level up and lowering the attenuator on the plate amp.

Um, no - I wouldn't do that.

I think Garry may have misunderstood your situation - your receiver only has speaker level (amplified) outputs - you can't bypass the amplification that occurs within the Sony HTiB system.

Any way you cut it, the output from the receiver (and thus the input to the subwoofer) will be amplified. Feed an amplified signal to a powered subwoofer and it will either bypass its internal amplification automatically, or will attempt to amplify the already amplified signal and risk damaging both units.

You can use a passive subwoofer on a system that does not have pre-outs, but you can't use an active subwoofer on a system without pre-outs.

I would say you need to consider ditching the low end Sony system and start from scratch (that uses proprietary connections and isn't much use if you are considering upgrading components).

The Klipsch sub in question has high level inputs.

Originally Posted by Robert_J /t/322480/adding-replacing-htib-sub-help#post_3952700
The Klipsch sub in question has high level inputs.

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Right, but doesn't using them mean that the receiver is still doing the amplification of the signal? I always thought that using the high level inputs (even on a powered sub) forces the sub to run in passive mode, in which case the OP's assertion that "...not requiring any additional draw of power from the receiver since the Klipsch sub is a self-sufficient powered subwoofer" is not the case.

The main problem trying to use a throw-away HTiB with a powered subwoofer is...
The output is not 200 watts(or whatever the BS speak is in the owners manual). It is more like 10-15 watts.
That, and the extreme distortion you get from attempting to get that 10-15 watts out of it will overwhelm a high level speaker input. (It has been tried repeatedly, have a fire extinguisher handy)...
If you must do this, or attempt it, you have to use an OUTBOARD speaker level to line level adapter(commonly used in car stereo).
And, most subwoofers, if you use the high level input, you also have to use the high level out to the satellites...as in YOU HAVE TO COMPLETE THE CIRCUIT.
Example of a speaker level to line level adapter...
http://www.amazon.com/Speaker-Level-Converter-Adaptor-Control/dp/B007VTMSEO/ref=sr_1_2?s=electronics&ie=UTF8&qid=1343062199&sr=1-2&keywords=speaker+line+level

Jason Charlton said:

Right, but doesn't using them mean that the receiver is still doing the amplification of the signal?  I always thought that using the high level inputs (even on a powered sub) forces the sub to run in passive mode, in which case the OP's assertion that "...not requiring any additional draw of power from the receiver since the Klipsch sub is a self-sufficient powered subwoofer" is not the case.

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Yes, the receiver amplifies the sub signal but not that much. How does that happen? The internal resistance of the high level input is so high that the LFE output is only a few milliwatts. Now it is at the same level as using the RCA input. It goes to the amp section of the sub just like the RCA connection.

Ok, I may have been misunderstood on the running a split wire thing but I know for a fact that running a sub woofer speaker level out to a sub with a high level in will work. I have done it several times. Never had a fire or equipment failure as a result. I have even ran a sub off the left and right "B" speakers on receivers that did not have a sub out. Granted the bass may not be as good doing that, but it still works. It's called budget short cutting, and I have always had to make the best of whatever I had available.

Originally Posted by Robert_J /t/322480/adding-replacing-htib-sub-help#post_3952733
Yes, the receiver amplifies the sub signal but not that much. How does that happen? The internal resistance of the high level input is so high that the LFE output is only a few milliwatts. Now it is at the same level as using the RCA input. It goes to the amp section of the sub just like the RCA connection.

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Huh, I learn something new every day. So you're saying the internals of the subwoofer will send any "low enough" signal to its internal amplifier, regardless of where that signal enters the subwoofer? I always thought the signal path of the speaker level inputs and RCA inputs were pretty much isolated from each other, at least until after the amplification of the RCA signal.

I guess these are the things you learn when you start building your own speakers!

I have even ran a sub off the left and right "B" speakers on receivers that did not have a sub out.

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This works with a regular receiver - but what we have here is a HTIB receiver - so it already has a cross over built in to the left and right speakers, sending the bass information to it's own sub. If you hooked up the left and right outputs into the sub, and then ran the speaker wire to the speakers (as you are describing) the sub would be getting the already crossed over signal - meaning there would be no bass information for the sub to work with...
This is one of the reasons that HTIBs are such a pain if you want to upgrade anything....unless you get one that uses a real receiver.....and this Sony is not one of these....

The biggest issues with "craptastic" HTiB are...
The distortion is off the charts.
PMPO power ratings are useless.
They get hot and die.
The biggest issue of attempting to use the subwoofer output into "some sort" of speaker level/line level adapter is...
An "all on one" PMPO rated HTiB does NOT have enough real power to do anything through a speaker to line level.
Those are designed to work with 50 watts or more(most, like the one I linked prior...have a gain control)...
Not 10. If this HTiB has more than 10 watts per channel...I'd shocked.

Thanks for all the replys.
So from my somewhat understanding of what you guys are saying, I am thinking I may be able to use the Klipsch sub?
Garry says he has done this in the past, although the sub may not produce the type of sound it is truly capable of, it should be better than what is there now.
I also see there is an issue of an amplified signal being sent from the HTIB receiver going to the input on the sub, however it seems like most people think that the amplified signal is not very significant. So am I wrong to think that this would almost be the equivalent of sending an un-amplified signal to the sub, thus meaning there should be no damage to the sub or the receiver since the sub will power itself?
The receiver should not get too hot and die. The last HTIB I had since 2005, and just gave it away to a friend recently, it still works fine. Mind you, the last one I did not make any changes too.

Ok, here are the main issues...
You have a PMPO rated HTiB based on 3 ohm. The Klipsch "high level" more than likely presents at 8 ohm.
So, you have "200watts PMPO at 3ohm". Reduce that to 1/4. You have "50watts PMPO at 8ohm".
Since PMPO is BOGUS, we can assume you have 10...maybe 15 watts at 8ohm.
That 10 watts is in the "I'm struggling here" territory.
You send that "I'm struggling here" power riddled with distortion into the high level input...
1. It will sound like highly distorted garble.
2. The high level to line level is not meant to be used with extreme distortion(IE it's gonna die eventually)
3. This is NOT the same thing as hooking up a "real honest too god" stereo receiver with 50wpc.
Put this into perspective about PMPO...
Take the "most powerful" 5 channel amp on the planet. (the Outlaw 7500...although it probably "isn't" the most powerful)
The Outlaw 7500 is a REAL 200wpc x5. Translated into PMPO is probably (and yes this is a joke, cause "no one really knows" how PMPO works)...
15,000,000 watts.

So from my somewhat understanding of what you guys are saying, I am thinking I may be able to use the Klipsch sub?

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I think that is what you want to hear.... but it is the exact opposite of that....it will not work on your system....at least not in a satisfactory way. It more than likely will end up frying your HTIB receiver and/or your new sub.
I would take the new sub, and use it as a corner stone for a new system....scrapping the sony HTIB and chocking it up as a lesson learned...

Lol, it's not what I want to hear, but it was my take-away from reading all the replies. Maybe I will just steer away from this for now, I don't need the extra bass, my system sounds just fine as is. I just thought since I have the opportunity to get this at a great deal, why not add some extra bass to my set up. I just didn't know it was so complicated, thinking it could just be added to the current set-up.

This is the email I received from Klipsch
You could use the speaker wire connections on the sub, from the left and right front channels.
But....some receivers from a Home Theater in a box may not allow for full range setting to the front speakers
Some will roll off the lower frequencies around 80 to 100 Hz.
The SW will need a full range signal
How does the sub supplied with the system get it's signal?
Speaker wire? Looking at the specs it looks like it does use speaker wire
If so you could use that wire to connect to either the left or the right high level input, you don't have to use both

Your HTiB is 6 channels. Not 5.
The .1 IS a channel.
In your HTiB it has a set-up where the .1 gets ALL THE BASS. The other 5 get EVERYTHING ABOVE BASS.
I have no idea(cause I couldn't care less about "one piece" HTiB) if there is a user selectable crossover. You would know that, you own it and have the owners manual.
If, and this is a big IF, you can set the front two speakers FULL RANGE, you "could" in theory run the Klipsch.
But...is the front LR settable to full range...???
You have the owners manual.
I'm going on the theory that there is no "user selectable crossover" cause it would be a useless feature to have with a "woofer" that probably barely creates even 70hz and the "other 5" speakers can barely produce 200hz.
So, you have a "bass attempting module" filling in something like 70hz to 200hz and then the other 5 speakers picking up from 200hz-ish to probably 15,000hz-ish...
Your ONLY HOPE is to connect the .1 speaker output to this Klipsch.
Period. End. Of. Discussion.