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Subwoofer Selection Criteria

watchnerd

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It would be much easier for you to set it up with measurements as this way it's pretty much trial and error.



Yes, that seems logical.
I don't disagree that measurements are the next step to refine things.

But I don't know if REW or similar would have provided any insights into the downsides of port plugging.
 

Krunok

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But I don't know if REW or similar would have provided any insights into the downsides of port plugging.
Plugging the port changes the LF frequency response significantly and REW, assuming you will be using a calibrated mike, measures FR much more precisely comparing to what you can hear. Frankly, I don't think good SW integration is possible without measurements.
 
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watchnerd

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I'd consider a higher XO frequency if I were you, more like 80Hz, for easier integration and less stress on the mains. But I know others here may disagree with me.
FWIW, I asked Dynaudio support:

"Dear Dynaudio,

What is the recommended high pass frequency when using using the Contour 20 with a subwoofer?"

Their reply:

"50hz"
 

Krunok

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FWIW, I asked Dynaudio support:

"Dear Dynaudio,

What is the recommended high pass frequency when using using the Contour 20 with a subwoofer?"

Their reply:

"50hz"
Let's put it this way: if you try to imagine your Contour 20 as a 3-way floorstander with the 3rd driver being your sub's woofer do you really think XO point between the sub's woofer and Contour's 7" LF driver would be set to 50Hz? Do you believe 7" LF driver would be able to reproduce the 50-100Hz range with higher SPL and lower distortion than your sub's woofer? I don't think so..
 

Soniclife

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Let's put it this way: if you try to imagine your Contour 20 as a 3-way floorstander with the 3rd driver being your sub's woofer do you really think XO point between the sub's woofer and Contour's 7" LF driver would be set to 50Hz? Do you believe 7" LF driver would be able to reproduce the 50-100Hz range with higher SPL and lower distortion than your sub's woofer? I don't think so..
And a near field measurement will confirm the point distortion skyrockets, around 100hz would be my guess. Reducing excursion by not making them produce low frequencies will lead to lower distortion throughout their range. It's all win.
 

watchnerd

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Let's put it this way: if you try to imagine your Contour 20 as a 3-way floorstander with the 3rd driver being your sub's woofer do you really think XO point between the sub's woofer and Contour's 7" LF driver would be set to 50Hz? Do you believe 7" LF driver would be able to reproduce the 50-100Hz range with higher SPL and lower distortion than your sub's woofer? I don't think so..
I understand your logic, which is why I found it interesting, but why would they intentionally mislead?

It could be they're optimizing for different criteria or have a different design philosophy.

Remember REL advocates running mains full range.
 

Olli

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From my experience, the right XO point depends on your room and the placement of your speakers and subs. I would try different XO points, measure the results in REW and look at the frequency response and the waterfall charts.

And I would also measure the effect of open vs closed ports. I would bet that closed is better, but worth checking.
 

watchnerd

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From my experience, the right XO point depends on your room and the placement of your speakers and subs. I would try different XO points, measure the results in REW and look at the frequency response and the waterfall charts.

And I would also measure the effect of open vs closed ports. I would bet that closed is better, but worth checking.
I tried closed -- it sounded awful. The woofer was overdamped, the dynamics were crushed, and the midrange and imaging became worse.
 

StevenEleven

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I’ve read a lot of these posts but not all of them, and I’m not nearly as knowledgeable as everyone here. My experience: you’re better off with two less capable subs than one more capable subs. I’ve got two 10-inch subs. I started with one ten inch and added another 10 inch and I felt a lot more confident in things.

If you are using it for music you are going to use it for the bottom octave or two of music. It will take a big load off of your receiver or amp if you use a crossover. The sub will most likely handle everything from 80 hz down better than your mains if you get semi decent subs. The addition of subs means a big increase in fidelity of recording reproduction from 80 hz or 60 hz on down below 40 hz.

For music 40 hz is a pretty critical area. If you’re good at 40 hz with no rolloff there it’s usually a big upgrade in sound. I personally would recommend an amp or receiver that handles the corossover characteristics for you. I cross over at 80 hz for the mains, you can take it down to 70 or 60 hz if you are paranoid about sound localization at low frequencies.

I would not run the mains at full frequency range in conjunction with subs, I’d cross over at some point one way or another.

It’s nice to have some digital eq for the subwoofers in specific and some room eq used in conjunction with you ears and common sense. I personally would concentrate on positioning of the subs first and DSP and eq second.

I prefer closed subs rather than ported. As I understand it if your main intent is movies then ported subs are better according to a lot of people. Handling movie soundtracks with aplomb requires a much more expensive subwoofer than one used mainly for music. I focused on music.

You should keep in mind that it gets pretty difficult to perceive pitch in 1/2 step gradations once you get below 40 hertz. So below 40 hz you are really trying to fill in and get realistic visceral sound but it doesn’t have to be super accurate, IMHO, if those super low frequencies are even in the music or the recording.

I tend to focus on what I am trying to get musically rather than focus on the technical audio side. A typical double bass in classical or jazz or rock (either electric or acoustic as the case me be) hits a low note of 41 hertz (an open E on the lowest string) or so. If the recording reproduces this having the subs give you that note cleanly is a big deal, IMHO. A lot of modern music has some synthesized bass below 40 hz, there are some electric double basses that have an extra string and go a little below 40 hertz, lots of organs do, pianos do but it’s largely obscured by harmonics. But a clean 40 to 80 hertz is pretty critical musically.

A lot of recordings and speakers deliberately emphasize harmonics above the lower fundamental frequency tones on purpose so it will still sound nice on normal gear. (Your brain infers the lower note from the harmonics.) But having your system actually hit the lower fundamental frequencies sounds really nice. Adding subs is often one of the most efficient ways to improve the actual fidelity of an otherwise well-functioning system, IMHO.

Don’t over-estimate what you need to spend on a sub or subs if it’s mainly for music at any kind of reasonable listening level. It’s too easy to get caught up in differences in capability you will never use just because measurements of those capabilities are out there.

End of brain dump.:)
 
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Krunok

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I understand your logic, which is why I found it interesting, but why would they intentionally mislead?

It could be they're optimizing for different criteria or have a different design philosophy.

Remember REL advocates running mains full range.
They didn't mislead. You asked oversimplified question for a complex problem and you got an oversimplified answer. What you need to understand is that when you are trying to integrate subwoofers with your mains you are working on a quite complex problem where finding the optimum XO point is one of the most crucial issues. If you don't measure FR at high SPLs and distortion of your SW vs your mains you are seriosulsy cutting the corners without a real chance to make it right.
 

Olli

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I even cross at 85, despite having really big floorstanders at home. You can easily see in measurements where the FR is most even.

In contrast, I cross at 52 in my office setup where I have rather small monitors (JBL 705). It really depends on the room and positioning of your speakers.
 

watchnerd

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They didn't mislead. You asked oversimplified question for a complex problem and you got an oversimplified answer. What you need to understand is that when you are trying to integrate subwoofers with your mains you are working on a quite complex problem where finding the optimum XO point is one of the most crucial issues. If you don't measure FR at high SPLs and distortion of your SW vs your mains you are seriosulsy cutting the corners without a real chance to make it right.
How high is high SPLs?
 

watchnerd

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If you’re not willing to use REW, Audiolense or something similar, this site has helped me when I was still doing it alll in the analogue domain: http://www.soundoctor.com/
Oh, it's not an unwillingness...it's a matter of time.

I only get about 40 minutes a day, on a good day, to listen to music. Often not even that. After a long day at work plus working out plus chores plus cooking for family plus walking dog, etc, when I finally get around to playing with my stereo between the hours of 9:30 and 10:00 pm, the last thing I want to do is spend my time setting up UMIK and measuring stuff.

I basically have to wait for a holiday.
 

Thomas savage

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Oh, it's not an unwillingness...it's a matter of time.

I only get about 40 minutes a day, on a good day, to listen to music. Often not even that. After a long day at work plus working out plus chores plus cooking for family plus walking dog, etc, when I finally get around to playing with my stereo between the hours of 9:30 and 10:00, the last thing I want to do is spend my time setting up UMIK and measuring stuff.

I basically have to wait for a holiday.
What about tasking the mother in law to sort your subwoofers?
 

Thomas savage

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The last task we gave her was to walk the cat.....which ended in screams and her falling down at the end of the leash as the cat decided he wanted to chase after and kill a juvenile opossum.
Walking a cat , on a lead ? What ? Why ? How ?

This thread really is the land of confusion.

There's no way your going to get this right in the time you have doing it by ear. You will be changing your mind and going nuts daily (even more nuts than a regular Joe the cat walker).

Its measurements and software or madness..

im still struggling with the whole ' my mother in law walks my cat ' thing ..

walking cats , anyone else think this is normal behaviour?
 

watchnerd

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Walking a cat , on a lead ? What ? Why ? How ?

This thread really is the land of confusion.

There's no way your going to get this right in the time you have doing it by ear. You will be changing your mind and going nuts daily (even more nuts than a regular Joe the cat walker).

Its measurements and software or madness..

im still struggling with the whole ' my mother in law walks my cat ' thing ..

walking cats , anyone else think this is normal behaviour?
The cat walking isn't my idea -- it's the wife's. Yes, I agree it's ludicrous.

But she sees cat walking videos on YouTube, and it gives her ideas:


And, you're right....I know I'm not going to get the sub dialed in optimally by ear.

But, for now, it's better than nothing. And, given my upcoming business travel and family vacation obligations, I probably won't have time to do it better until November when Thanksgiving rolls around.
 

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