Summits crossover

[khenegar]

Can any recommend a crossover point for the summits to the depths? now I'm crossing them over at 40hz. Presently using a lexicon Mc12v5eq. Thanks

 

[RUR]

Two things to consider when selecting a crossover point:

1) As you move the crossover higher, you lessen the load on the Summit woofs, rendering the upper bass covered by the Summits generally more accurate.

2) If you can examine FR plots for the Depths vs. the Summits via REW/XTZ/Omnimic, you can see how the Summits vs. Depths positioning affects modal behavior. If the Summits have wild swings up through say 60Hz and the Depths do not (again, due to relative position in the room), it pays to have 60Hz reproduced by the subs, etc. This is a compelling argument for separate, properly-placed subwoofers in any setup.

For both of these reasons, I cross my Summits to the subs @ 80Hz. Use the highest, even-order filters your Lex will permit.

Good luck!

/Ken

 

[Hocky]

Two things to consider when selecting a crossover point:

1) As you move the crossover higher, you lessen the load on the Summit woofs, rendering the upper bass covered by the Summits generally more accurate.

2) If you can examine FR plots for the Depths vs. the Summits via REW/XTZ/Omnimic, you can see how the Summits vs. Depths positioning affects modal behavior. If the Summits have wild swings up through say 60Hz and the Depths do not (again, due to relative position in the room), it pays to have 60Hz reproduced by the subs, etc. This is a compelling argument for separate, properly-placed subwoofers in any setup.

For both of these reasons, I cross my Summits to the subs @ 80Hz. Use the highest, even-order filters your Lex will permit.

Good luck!

/Ken

In my room, I let my Summits play full range with my subwoofer. 3 bass sources in the room really helps to even out the response.

 

[RUR]

In my room, I let my Summits play full range with my subwoofer. 3 bass sources in the room really helps to even out the response.

Hi Hocky,

Over at AVS, there was a lengthy discussion with a strong proponent of this approach. There are advantages (more bass sources à la Geddes) and disadvantages, including phasing issues and the increased distortion of upper bass frequencies (vs. Xover) I noted above. No question that it's subjectively preferred by some folks and worth the experiment, though the vast majority preferred a crossover, typically in the 80Hz range.

This was some time back, but I'll see if I can find a link.

 

[Hocky]

Hi Hocky,

Over at AVS, there was a lengthy discussion with a strong proponent of this approach. There are advantages (more bass sources à la Geddes) and disadvantages, including phasing issues and the increased distortion of upper bass frequencies (vs. Xover) I noted above. No question that it's subjectively preferred by some folks and worth the experiment, though the vast majority preferred a crossover, typically in the 80Hz range.

This was some time back, but I'll see if I can find a link.

I think it probably varies a lot from room to room depending on interaction as well as low frequency output capability of the speakers. It does pretty well in my combo. The bass response is much better both before and after EQ running that way in my room.

 

[RUR]

I suspect that the most important goal is to achieve the most linear response in the bass region, whether accomplished via careful placement or EQ or both.

As for the distortion reduction, this is easy to hear, particularly in vocals, as one increases the crossover frequency, always assuming one has sufficiently competent subwoofer(s). The four 10" woofs in my Summits simply can't compete in these frequencies with the SubMersive/JL combo - the subs are far more accurate.

 

[Hocky]

I suspect that the most important goal is to achieve the most linear response in the bass region, whether accomplished via careful placement or EQ or both.

As for the distortion reduction, this is easy to hear, particularly in vocals, as one increases the crossover frequency, always assuming one has sufficiently competent subwoofer(s). The four 10" woofs in my Summits simply can't compete in these frequencies with the SubMersive/JL combo - the subs are far more accurate.

I think they're probably more accurate at sub 30hz and high spl for sure. The rest of the circumstances... I don't know. I would like to see graphs.

 

[RUR]

I think they're probably more accurate at sub 30hz and high spl for sure. The rest of the circumstances... I don't know. I would like to see graphs.

Dunno what you consider to be high SPL, Hocky, but I typically listen at 80-85dB, which means that I'm often experiencing musical peaks with plenty of LF content at 100dB and more. While we'll never see graphs of the Summit 10" driver, I think it's fair to say that they'll measure less well below 100Hz than a properly-designed 10" subwoofer, no? The 2x10" Summit drivers are a compromise, designed to cover a fairly wide FR band from 24-260Hz and driven by 200W each.

The subwoofer, OTOH, is designed to cover a significantly narrower FR band, typically 20-125Hz, with a more robust driver, suited to the FR band and typically driven by something like 500W. The comparison becomes even more lopsided when we look at larger subs e.g. two 15" drivers powered by 2400 watts.

Meanwhile, why would we think that the Summit driver will be as accurate pushing 80-260Hz content while simultaneously performing heavy lifting @ 20-80Hz vs. the much easier job of pushing only 80-260Hz? This, at least, can be empirically demonstrated by moving the sub crossover upward from e.g. 40Hz to 80Hz while listening to upper bass content. In every system I've had, increasing crossover frequency resulted in easily audible improvement to upper bass clarity.

 

[Hocky]

Dunno what you consider to be high SPL, Hocky, but I typically listen at 80-85dB, which means that I'm often experiencing musical peaks with plenty of LF content at 100dB and more. While we'll never see graphs of the Summit 10" driver, I think it's fair to say that they'll measure less well below 100Hz than a properly-designed 10" subwoofer, no? The 2x10" Summit drivers are a compromise, designed to cover a fairly wide FR band from 24-260Hz and driven by 200W each.

The subwoofer, OTOH, is designed to cover a significantly narrower FR band, typically 20-125Hz, with a more robust driver, suited to the FR band and typically driven by something like 500W. The comparison becomes even more lopsided when we look at larger subs e.g. two 15" drivers powered by 2400 watts.

Meanwhile, why would we think that the Summit driver will be as accurate pushing 80-260Hz content while simultaneously performing heavy lifting @ 20-80Hz vs. the much easier job of pushing only 80-260Hz? This, at least, can be empirically demonstrated by moving the sub crossover upward from e.g. 40Hz to 80Hz while listening to upper bass content. In every system I've had, increasing crossover frequency resulted in easily audible improvement to upper bass clarity.

I think that you're over simpifying it. I don't disagree that the sound changes moving the crossover around, but I don't know that what you're hearing is distortion differences or necessarily better or worse. Short of measuring it, I really don't know. I don't think that 40-100hz is going to be working hard for the summit woofers, even at 100db. I think you're underestimating them - I would bet that those two woofers are probably superior to most of the subwoofers on the market that don't cost big bucks. They're certainly stronger than all of the sub $1000 subwoofers that I have had in my house. For what it is worth, I have a very strong subwoofer (F212), have had Descents, and in my room listening to lots of different combos and corssovers over time, full range with the subwoofer plays the cleanest and most impactful. Maybe I'll get bored one day and actually measure it to see what the distortion levels look like.

 

[RUR]

I think that you're over simpifying it. I don't disagree that the sound changes moving the crossover around, but I don't know that what you're hearing is distortion differences or necessarily better or worse. Short of measuring it, I really don't know. I don't think that 40-100hz is going to be working hard for the summit woofers, even at 100db. I think you're underestimating them - I would bet that those two woofers are probably superior to most of the subwoofers on the market that don't cost big bucks. They're certainly stronger than all of the sub $1000 subwoofers that I have had in my house. For what it is worth, I have a very strong subwoofer (F212), have had Descents, and in my room listening to lots of different combos and corssovers over time, full range with the subwoofer plays the cleanest and most impactful. Maybe I'll get bored one day and actually measure it to see what the distortion levels look like.

Hocky, I guess we'll have to agree to disagree on much of the above, but let me leave you to ponder the following...

KEF and Revel, two of the most anti-BS, science-based speaker designers on the planet, create extremely well-regarded speakers with the following characteristics:

Revel Salon 2
3 x 8" bass drivers (roughly same surface area as 2 x 10") 23-150Hz, crossovered to 1 x 6.5" mid-woofer which reproduces 150-575Hz (male and female vocal fundamentals fall within this range)

KEF Reference 207/2
2 10" LF drivers 26-110Hz crossovered to a third 10" LMF which reproduces 120-350Hz (ditto)

i.e. they're not asking their very capable LF transducers to also reproduce upper bass/low mids. And knowing the companies involved (unlike many others I could name), you can bet they're not choosing this approach for whimsical reasons.

 

[Hocky]

I think the discussion really only comes down to one thing: every design has problems. To the point of the original topic, just try everything and see what works best for you and your room. ;-)

 

[khenegar]

crossover/setting

RUR: i was told by a reliable source to use 65hz crossover for music and 80hz crossover for movies. question do you set the crossover for the depth and summit the same? thanks for the information.

 

[RUR]

RUR: i was told by a reliable source to use 65hz crossover for music and 80hz crossover for movies. question do you set the crossover for the depth and summit the same? thanks for the information.

Yes, the filters for both Depth and Summit are typically the same frequency. Dunno why one setting for movies and one for music, but as Hocky has said, it's all about what sounds best for you, so experiment until you find a setting you like.