Emotiva X-Ref 12 Subwoofer Review

[theJman]

For all of the listening sessions the Emotiva X-REF12 was placed in the front right corner of the room firing into the corner about 4 inches from the walls.

I see this (or similar) wording in most of the subwoofer reviews. Is that to be taken literally, as in you're aiming it into the corner so the sound is reflecting off the walls? If so, what's the advantage to doing it that way? I don't recall ever seeing a subwoofer oriented in a similar manner when used at home. It seems to me the output would be greater were it firing directly at you, instead of away from you.

Bump.

And the answer is?

 

[Ricci]

That is correct.

I have done extensive measurements in my room and this results in the smoothest upper bass response from the sub. Typically when you have the subwoofer firing towards you this places the radiation point 2 to 4 feet from the wall behind and this causes a cancellation notch in the upper bass due to reflections from the wall. Usually this ends up falling in the typical crossover region of overlap between the mains and sub. Having the radiation emit from closer to the wall pushes this cancellation in the sub response much higher in frequency and outside of the subwoofer range.

You might also assume or see it said that this will lower the upper bass output from the subwoofer since it is facing away from you. Outdoors or anechoically this would be true, but in a room with large boundaries in close proximity such as inside of a vehicle or in a room corner this is often not the case.

This is a general observation but each situation can be different due to a huge variety of factors and should be investigated through measurements in order to obtain the best results and sub placement.

 

[theJman]

Does the same hold true if you point a sub at a single (flat) wall? I don't have the option of corner placement, but now I'm intrigued to know if this works unilaterally with any wall surface.

 

[Ricci]

Essentially yes but your listening placement and other boundaries and objects also matter. This is why groundplane measurements are done the way that they are. With the microphone and subwoofer both on the ground in theory you only get one perfect reflection of energy from the ground through the bass range. This is known as half-space and provides basically 6dB of gain over a reflection free anechoic environment. If you were to raise the microphone the subwoofer, or both away from the ground you would start to see some response changes due to the distance from the boundary represented by the ground.

 

[tattoo_Dan]

Essentially yes but your listening placement and other boundaries and objects also matter. This is why groundplane measurements are done the way that they are. With the microphone and subwoofer both on the ground in theory you only get one perfect reflection of energy from the ground through the bass range. This is known as half-space and provides basically 6dB of gain over a reflection free anechoic environment. If you were to raise the microphone the subwoofer, or both away from the ground you would start to see some response changes due to the distance from the boundary represented by the ground.

so you're saying it's better to put the calibration mic on the floor for sub calibration ?

I have 2 Emotiva ultra 12 subs,one on the front wall facing into the room,and one on the rear wall facing into the room,each is about 5 feet from a corner,and I have a Auralex gramma under each one,

and I use a Anti-Mode 8033,I have always put the mic on a tripod in the main seating area at ear level.

 

[Ricci]

so you're saying it's better to put the calibration mic on the floor for sub calibration ?.

NO.

You want it where your head is at the listening position.

 

[tattoo_Dan]

NO.

You want it where your head is at the listening position.

that's what I have been doing,I must have misunderstood your post

With the microphone and subwoofer both on the ground

thanks

 

[zhimbo]

Ground-plane measurement is a specialized procedure for measuring performance and output of a subwoofer, a procedure normally done *outside*, to eliminate room effects. You're talking about measuring what you are hearing in your specific room and setup. If you want to measure what you hear, put the mic where you do your hearing.

 

[josinha]

This might be a stupid question,
but since I saw you tested both, would this sub be better or worse then a KRK 10s for a 2.1 musical system with powerd KRK monitors?
I know this goes way lower and has DSP, but the the KRK might be more musical? (I would use an external crossover with the Emotiva)

 

[shadyJ]

This might be a stupid question,
but since I saw you tested both, would this sub be better or worse then a KRK 10s for a 2.1 musical system with powerd KRK monitors?
I know this goes way lower and has DSP, but the the KRK might be more musical? (I would use an external crossover with the Emotiva)

Josh Ricci hasn't been around these parts for awhile. From looking at the available data, I don't think either sub would have a huge advantage over the other. The KRK would have a bit more mid-bass headroom, but the Emotiva sub has a more liner response. What will make a bigger difference than what sub you choose is how well you integrate them with the speakers. Make sure the sub is in phase with the speakers, and place the sub in a location where it yields the smoothest in-room response. Also choose a good crossover frequency for it to blend in best with the speakers.

 

[theJman]

You do realize this thread died over 8 years ago and that the X-Ref is no longer made, right?

 

[josinha]

Josh Ricci hasn't been around these parts for awhile. From looking at the available data, I don't think either sub would have a huge advantage over the other. The KRK would have a bit more mid-bass headroom, but the Emotiva sub has a more liner response. What will make a bigger difference than what sub you choose is how well you integrate them with the speakers. Make sure the sub is in phase with the speakers, and place the sub in a location where it yields the smoothest in-room response. Also choose a good crossover frequency for it to blend in best with the speakers.

Thanks,
I was wondering about the DPS boost on LF of the Emotiva. reading the article again there is indeed groupdelay/distorsion going on in that region.
I am actualy using DSP/DRC in my computer. I see 2 advantegas though in the Emotiva: no port makes it more versatile in placing. for example I can place it facing the wall to minimize speaker boundary interference. And the variable phase; could be usefull while trying out a nearfield placement

You do realize this thread died over 8 years ago

Yea. the dates are all over the place. nice

and that the X-Ref is no longer made, right?

You do realize that when someone asks between 2 kind of distinct products there must be a reason for it? I have an offer for either of them used

 

[theJman]

You do realize that when someone asks between 2 kind of distinct products there must be a reason for it?

Frequently there's not, especially when the thread has been in mothballs for so long and the item in question hasn't been available for years.