Finally pulled the trigger.

[billy p]

Just to address this...
Because some manufacturers put a sub driver in a tower speaker does not mean it is the best practice.
As mentioned before, in a room, the best location for the sub is rarely the same as the other aspects of the sound.

In other words...if it looks good...it won't sound good.

[davef]

Great info Dave! thank you. However i fail to see the difference between placing the speaker on top of the sub, and a tower speaker with the sub already in the same box?

Because the speaker with the sub already in the same box has the size of the front baffle already compensated for in the baffle step compensation network of that speaker's crossover, or at least - in any well designed speaker...

Plus , as bass (and its harmonics) become directional as frequency increases, its always been said to keep the sub close to, or centered between the stereo pair. Or, when using 2 subs, close to L+R.

No, that's late 1980's theory on subwoofer placement, and it's been proven completely wrong. Yes, frequencies above 80Hz become directional, but modern subwoofers are generally not going to be playing much, if anything above 80Hz. You need to understand that the wavelengths produced by your subwoofer are typically longer than your room itself, as such - there is no directionality regardless of where the sub is placed in the room - and the ideal placement in any room is where the sub least excites room modes. Many customers prefer to place the sub on the opposite side of the room, or just to the left or right side of the couch. It is always best to spend the time to find the proper subwoofer location for your room. Doing so is easy, and the easiest procedure is the "subwoofer crawl".

https://www.audioholics.com/home-the...ofer-placement

Or, when using 2 subs, close to L+R. I understand that sub placement affects room interaction, but i also understand you need a centered soundstage.

With proper subwoofer integration and crossover, the sub has zero effect on soundstage and simply sounds like the bass is coming from the 2 speakers. Plus, nearly all music and movie soundtracks record bass in mono - not stereo or multi-channel. Reason for this is obvious, because it is non-directional and stereo/muti-channel bass below 80Hz makes no sense. Therefore, because it is monaural - it can not effect your soundstage. The bass harmonics you mention, will mostly be frequencies above 80Hz and produced by the speakers, not the sub.

Even with my sub set at 65, i can tell where it is! (now everyone is gonna tell me i need a new sub) Also to note is that my sub max setting is 90Hz.

There are a few possibilities for this. Your subwoofer is quite old and I am unable to find even a shred of information on it. Low pass filters are not brick walls, depending on the slope of the LP filter in your subwoofer, even setting it to 65Hz can still mean that plenty of information above 80Hz is getting through. Modern subwoofers, as well as receivers/processors use a very steep low pass filter slope (typically 24dB/octave or even 36dB/octave). The low pass filter slope in your subwoofer might only be 12dB/octave, or even worse - 6dB/octave.

The other possibility is that your subwoofer is causing items close to it to rattle - thus producing sound that will be quite directional. You might not notice this rattle, but it will give away the subwoofer location every time. One way to test for this is to see if the sub becomes more directional as you increase your volume - if it does, there you have it.

Do you have specifications on your subwoofer that you can share?

[davef]

That WAS one thought i had! So by this logic, as long as you put a (narrow) spacer of some sort between the speaker and the sub, it should be ok?...and it is of sufficient height? Of course i cant do that with my sub because its already 4+ft tall.

I understand the thought process to come to this conclusion, but this is not how it works. Sound waves and light waves are very similar. Shine a flashlight down a board, notice the pattern of light. Take the same board, break it in half and separate the 2 by an inch or two creating a small space between them (your spacer). Does that small space between the 2 boards stop the light waves from hitting the second board?

In your example, sound waves that are longer than the space are simply going to pass right over this, waves that are shorter, are going to diffract (change direction).. Adding a small space like this actually makes things worse... Keep large obstacles away from your speakers, if at all possible.

[Qman]

Just to address this...
Because some manufacturers put a sub driver in a tower speaker does not mean it is the best practice.
As mentioned before, in a room, the best location for the sub is rarely the same as the other aspects of the sound.

If you expect the woofer(s) in a tower speaker to play below say 80Hz, then it IS acting as the subwoofer, relative to our discussion here with regards to bookshelf speakers. How is this different than Ascend towers running full range?

[Qman]

I understand the thought process to come to this conclusion, but this is not how it works. Sound waves and light waves are very similar. Shine a flashlight down a board, notice the pattern of light. Take the same board, break it in half and separate the 2 by an inch or two creating a small space between them (your spacer). Does that small space between the 2 boards stop the light waves from hitting the second board?

In your example, sound waves that are longer than the space are simply going to pass right over this, waves that are shorter, are going to diffract (change direction).. Adding a small space like this actually makes things worse... Keep large obstacles away from your speakers, if at all possible.

So what is the difference between a floor speaker stand (spacer) and a speaker stand (spacer) that sits on top of a sub... lets say by 2-3 feet above the sub? Are you saying that there should be nothing besides the smallest speaker stand possible for many feet in all directions around the speaker? That's just not going to be possible for most of us!
So, if you look at my pic of the HT setup where the speakers are sitting on the stand, you're saying this is not a good spot because of all the surface area below the speaker, And the TV panel beside it?
And what about the Duo? I see it placed in cabinets, against walls, etc...clearly it isnt designed to be isolated on a stand....so where should it be? It seems better as i pulled it away from the TV and actuallly set it on the 2ex box in front of the TV....but still boomy/boxy. Hoping that is all in my reciever.

[Qman]

finally able to get a pic of the control panel of my Sub...I have a splitter cable coming from the receiver to both of the RCA jacks, (removed for picture clarity) sub back pacemaker.jpg

[davef]

If you expect the woofer(s) in a tower speaker to play below say 80Hz, then it IS acting as the subwoofer, relative to our discussion here with regards to bookshelf speakers. How is this different than Ascend towers running full range?

Because in the context of this discussion, we are discussing baffle step compensation and the problems created when you place a bookshelf speaker on top of a baffle that is considerably wider than the front baffle of the speaker. The difference with a well designed tower speaker and placing a bookshelf speaker on top of a such a large object is that out tower speaker has the proper amount of baffle step compensation to correct for the baffle size of the speaker (which doesn't change).

In your scenario, the bookshelf speaker has the proper amount of BSC to accommodate for the width of that speaker, - by placing the speaker on top of such a large baffle, you are increasing the front baffle width, for which the BSC circuit in the crossover is not optimized for. This will affect upper bass and midrange performance.

Since it doesn't seem like you are fully understanding what baffle step compensation is, I suggest googling it.

[davef]

So what is the difference between a floor speaker stand (spacer) and a speaker stand (spacer) that sits on top of a sub... lets say by 2-3 feet above the sub? Are you saying that there should be nothing besides the smallest speaker stand possible for many feet in all directions around the speaker? That's just not going to be possible for most of us!
So, if you look at my pic of the HT setup where the speakers are sitting on the stand, you're saying this is not a good spot because of all the surface area below the speaker, And the TV panel beside it?
And what about the Duo? I see it placed in cabinets, against walls, etc...clearly it isnt designed to be isolated on a stand....so where should it be? It seems better as i pulled it away from the TV and actuallly set it on the 2ex box in front of the TV....but still boomy/boxy. Hoping that is all in my reciever.

As you likely have noticed, nearly every speaker stand option out there has a width that is smaller than the speaker being placed on it. Besides it looking good, there is a reason for this that I and others have tried to explain.

That said, you originally stated using as small of a spacer as possible. Now you are mentioning a spacer that is 1-2 feet. With a 2 foot high spacer that is at least as narrow as the speaker, the effects of the extended baffle would likely be inaudible.

[davef]

finally able to get a pic of the control panel of my Sub...I have a splitter cable coming from the receiver to both of the RCA jacks, (removed for picture clarity) sub back pacemaker.jpg

Thanks for posting this. I do not see an adjustable low pass filter on this subwoofer. I see 2 options, either 40Hz or 90Hz. If you do not wish to update your receiver or update your subwoofer, your only option is to set your receiver at the lowest crossover point it allows (100Hz) and set your subwoofer to 90Hz. From there, adjust your volume control on the subwoofer to your personal taste.

I also recommend doing the subwoofer crawl as I previously mentioned, but this is a HUGE subwoofer so your placement options are likely limited due to aesthetics. Honestly, subwoofer technology has vastly improved since this sub was manufactured (1998) and you can get a new subwoofer that is half this size, likely even more than half this size - that will easily outperform this unit in every aspect.



This is far from proper sub/speaker integration, but it is the best you will be able to do with the electronics you have.

[white_darren]

finally able to get a pic of the control panel of my Sub...I have a splitter cable coming from the receiver to both of the RCA jacks, (removed for picture clarity)

Why a splitter (Y-) cable? I'm assuming receiver has mono pre-amp out and sub takes mono in on left RCA. Not sure it really matters, just curious. Perhaps it was just the cable you had handy at the time.