Speakers + Sub

[icor1031]

Because you can change the volume on your sub, and we are less sensitive to sub frequencies (thus turn it up?), how do you smooth the low Hz coming from your speaker to match with the sub?

Example, your speakers do F3 @ 60Hz. Your voices are 65dB, which puts 60Hz @ 62dB.

But, your sub 72dB is @ 59Hz.

How do you level this out? That's a big difference.

Thanks.

[generic]

It generally takes some sort of pre-amp/AVR that has a internal crossover for the sub and mains. Instead of crossing over at the main speakers roll off point, cross much higher, like 80hz.

[monoiz15]

I was thinking about building a sub to go along with my D8s, and also an enclosure for the Sure 4x100W amp board i have, when I thought, I could build just a little wooden box with a clear plastic top and some LEDs inside it just for a crossover. I haven't designed a crossover before but I've been learning more about it. Could be a fun project, and specifically designed for your set up.

[icor1031]

Well mate, the thing is that this applies to 80Hz. (And I do have a receiver with crossover.)

Your speakers are f3 @ 80Hz for 62dB, and voices 65dB.
Your sub is 72dB @ 79Hz.

How do you level this out?

Basically, I am asking: How do you make the speakers play bass louder, so they are close in volume to the sub, just before the crossover point?

MOREOVER, on a Different note:
When I cross my sub much above 60, it becomes directional. I assume it's because too much signal from above 80 goes to it. So, I'd like to cross lower.

It generally takes some sort of pre-amp/AVR that has a internal crossover for the sub and mains. Instead of crossing over at the main speakers roll off point, cross much higher, like 80hz.

[generic]

Now I'm a little confused. Your first example was at 60hz, but now it sound like you have a roll off you don't want at 80hz? Is this correct?

If your speakers have a natural roll off before the 80hz crossover point then you might want to try crossing over at 100hz.

Or you can try and play with any bass gain you might have in your receiver, but it will likely cause a rather large bloat across more of the bass range then you want.

As far as making speakers play more bass. You can't. You can just move the crossover point up so your sub plays the bass your mains can't.

[djkest]

Doesn't the gain on your subwoofer amplifier allow you to level match?

[TommyRocker]

If I understand the question, the answer is to turn the sub down to match your speakers. I'm not a fan of crossing my own sub higher than is absolutely necessary.

[icor1031]

Interesting thread tag. I'll try to make it less cryptic,

I am giving examples, not "my" case - although it easily could be. All I would have to do is turn up my sub, without turning up my speakers.

Now,

As far as making speakers play more bass. You can't.

What if you build electronics to create a sloped boost for your speakers, from 81 to 125Hz?
i.e. 81Hz is +9dB, 125Hz is +0.1dB (slope example)

Is this not possible with electronics?
Would it make the speakers distort?
etc.

--------

The reason I ask, some people like to play their bass louder than their voices.
So, where ever your crossover is, you will have a sudden jump. Your sub will be, for example, 10dB louder at 80Hz than your speakers are at 81Hz, because your speakers are turned down. (having your sub louder than the voices.)

And this is theory, partly why I ask - I assume it plays similarly it in real-life. If not, please explain.

Thanks.

[killa]

You could us a eq but your drivers wouldn't care for it too much if you boost them like that. you have a sub to take the strain off the mains so why add more back too them. It would be best to reduce the subs level. If you are using those small hivi speakers they will probably start to sound like mud if you boost them like your example.

[Whitneyville1]

Think of your speakers as they did 80-90 years ago when speakers reproduced very narrow frequency range properly. They had super tweeters, tweeters, upper mid-ranges, mid-ranges, mid-woofers, woofers and sub-woofers all driven by totally separate amplifiers in movie and live stage theaters. The super tweeters didn't have to handle hardly any power at all, because so little musical information was that high. The tweeters had to handle more power, but still not very much, again, there just isn't that much information in most music above about 5Khz. The upper mids got a good work-out with Jennette McDowell the high colturo soprano. Mae West worked the mid-ranges to death, while "Mom's" Mabley worked the mid-woofers with her husky female bass voice, so did Bing Crosby's Baritone voice. The woofers were worked with Joe Robeson's deep bass voice on the all synced sound first release of "Showboat" on "Ol' Man Ribber" while the sub-woofers pumped out the bass fiddles and bass horns of Paul Whiteman's Orchestra. I think you need to back you sub gain back down. Try "too little" until you get accustomed to that, then start slowly increasing the sub volume. You can go on-line and down-load frequency sweeps (a slow or very slow sweep of sine wave is easier to hear and identify) and play it back from bottom to top. You shouldn't hear any point where the sub-woofer stops playing and your mains start playing. It should be a totally smooth transition. It really won't be, but do your best to adjust your sub so the change is as smooth as possible. When you go from your 3" drivers to your sub-woofer at ~ 80 Hz, you'll FEEL it. A dB meter can be helpful to set-up the "Q" of the sub with your SA-240 amp and the level, but careful listening can get you there too. Put on Willie Nelson's "Countryman's" CD, and you'll be turning down the gain knob on your sub to about 1/16" from minimum! Larry Strelckecky pounds out his 5 string bass on that CD. Try the track "Do You Mind Too Much if I Don't Fall Again"

[icor1031]

Thanks, Whitney. You're probably right, I need to turn down my sub and all will be well.

[fastbike1]

This is what the setup routine in an AVR is for. You match levels for each channel. AVR plays a tone and you use a meter to check SPL, then adjust channels up and down to get even response.

If you don't have capability in receiver, you start w/ a test tone that both the sub and mains can play, then adjust mains for comfortable level and measure w/ SPL meter. Disconnect mains and play test tone again. Adjust sub until ouput matchs what you had w/ mains.

[icor1031]

No, mate. I wanted my speakers to have Quieter mids than my sub's bass, but transition into the dB of the sub well. With a slope as I posted above.

This is what the setup routine in an AVR is for. You match levels for each channel. AVR plays a tone and you use a meter to check SPL, then adjust channels up and down to get even response.

If you don't have capability in receiver, you start w/ a test tone that both the sub and mains can play, then adjust mains for comfortable level and measure w/ SPL meter. Disconnect mains and play test tone again. Adjust sub until ouput matchs what you had w/ mains.

[Leroy R]

What about setting the crossover frequency in your amp at say 80Hz and the crossover frequency on the sub amp at say 70Hz. This way the sub will start tapering off sooner and may be down to the same level as the mains by the time the two meet. You would still have the boosted low end, but the transition to the mains would be smoother.