Subwoofer question

[MADCOW]

Ok, I read the multiple subwoofers article, but it doesn't exactly anwser my question, and I have no experience with multiple subwoofers.

I have an extra sub that I no longer use in my bedroom. It is an 8 inch sub, of the exact same manufacturer and model of the 10 inch I use in my living room.

My 10 inch bottoms out at 23hz +/- 3 db and the 8 inch 26hz +/-3db. The 10 inch is 300 watts RMS, the 8 inch 200 watts RMS. Other than that, they are identical subs.

Now I have read many opinions on how if one sub bottoms out sooner than the other, then after you callibrate the subs to optimal levels, you will lose volume on the extra few HZ that the better sub can do and the lesser sub cannot do because you end up turning the levels down on both compared to what you would have either at alone.

Well that makes sense to me, so in order not to "lose" these 3 hz in my case, I was thinking about using the 8 inch from the "front pre out" jacks, to supplement the fronts, and the 10 inch as the LFE.

So a question is, if my fronts are set to small, and the crosser over set to 60hz, and let's say I have the bybass on the 8 inch set to 120hz, then would the 8 inch in this case be running bass from 120hz down to 60hz, where the other sub would take over? Does the receiver's crossover setting effect the front pre out? Because if it does, which I think it does, wouldn't this be the best way to use two different size subs without the smaller one "holding back" the bigger one?

In my case my 8 inch produces way higher quality bass than my front speakers do, so, would using the 8 inch to supplement the fronts, and the 10 inch for LFE be a good option, for getting the most out of each sub, and does the crossover effect the front preouts?

Also, if I'm using two subs for completely different frequency ranges, would the two subs play any or as much a role in a more even bass distrubution in the room, as what would normally occur from two identical subs in optimal placement from sub out?

 

[croseiv]

Usually, it is rather more difficult to intergrate to very different subs effectively. It looks like they are sort of close FR and power wise, so it may work. If you had two identical subs co-located, you could theoretically expect the bass to be twice as loud (a gain of 6 dB). You will get something less than that (possibly 3 dB?) with what you have. However, there's absoultely nothing wrong with trying it to see how it sounds.

The cross over setting only cuts the high frequncies, not the low. I would initially place them close to each other (maybe stacking) the see how that sounds.

 

[bandphan]

Running an external crossover like the berhinger dcx 2496 is good way to intergrate subs. Especially non identical subs.

 

[MADCOW]

Yeah, but in this case, if it works, like I stated, each sub will be responsible for a seperate frequency range. There will be no overlap, so why would there be a volume gain at all?

As long as the receiver's crossover setting effects front preout, I can't see why this wouldn't work.

I will have to hear how it sounds for sure, I just want to know the tech ups and downs relative to my plan.

 

[croseiv]

Also, it would help to know what brand of subs you have.

 

[mike c]

yes, i would experiment exactly the way you outlined.

fronts to small; 60hz crossover; 8" sub playing as high as 120 or 110

 

[MADCOW]

The 10 is a Mirage Prestige s10/ Energy ESW v10.

The 8 is an Energy ESW v8 that used to be part of my bedroom setup which doesn't exist anymore. And let me say, this little 8 inch blows away many so called "good' 10 inchers and even a lower end 12 inch Velodyne I came across, although that is not relevant here.

(Don't worry I got these subs cheap, I know the 8 and the 10 is way overpriced at it's normal almost $900 retail.)

 

[croseiv]

Okay, I got ya. The 8" will be a mid bass module, plus the 10" for LFE.

As mike c said, follow your plan and see how it sounds...

 

[highfigh]

Yeah, but in this case, if it works, like I stated, each sub will be responsible for a seperate frequency range. There will be no overlap, so why would there be a volume gain at all?

As long as the receiver's crossover setting effects front preout, I can't see why this wouldn't work.

I will have to hear how it sounds for sure, I just want to know the tech ups and downs relative to my plan.

There's always some overlap because the lowest end of each speaker falls off at a specific rate/octave. The 8" won't do 23Hz as well but there's still some energy there. Whether it's audible depends on the room and where you are, relative to the speaker and room modes.

Any difference you hear between the two subs isn't because of the 23-26Hz range. 3Hz isn't enough of a difference to matter unless you're listening to synthesized bass and your room is of adequate size/proportions to reproduce it. There's almost no music in that range, although special effects can go down there. Also, the sub isn't doing 23HZ or 26HZ+/-3dB, the frequency response curve has that much variation. If you get 26Hz from the 8" and it's -6dB below the reference, it'll take 4 times the power to hear it at the same SPL as the reference. Your room modes may actually cancel any added energy at 23Hz, depending on your listening position and speaker location.

That said, it won't hurt to try it in a few different locations to find out if it helps, or not.

 

[MADCOW]

There's always some overlap because the lowest end of each speaker falls off at a specific rate/octave. The 8" won't do 23Hz as well but there's still some energy there. Whether it's audible depends on the room and where you are, relative to the speaker and room modes.

But if I'm using my 8 inch is a "mid bass module", won't it be cut off at 60hz anyway?

 

[markw]

If you want a sub to blend in and become (acoustically) invisible, the secret is to cut it in at as low a frequency as possible.

By cutting the sub at a high frequency like 120 hz, your attention will be drawn to it when it's in use, which will be often.

IMNSHO, even 80 hz is a bit high, but it seems to have become a standard in home theatre. When I ran one with my maggies, I cut in in around 50 hz.

 

[MADCOW]

Only the 8 inch sub will be cut in higher, and will be used for only mid bass and blended into the fronts appropriately, the LFE sub will be cut in at 60hz.

Is that still an issue? I think it would be eaier to adjust levels on a sub your not using for LFE to blend into the fronts? No?

 

[markw]

whatever...

If you really think augmenting the upper/mid-bass is going to improve your system then go for it.

 

[MADCOW]

If you really think augmenting the upper/mid-bass is going to improve your system then go for it.

How can you even make a comment like that, not even knowing what my front speakers are or what they are capable of?

Of course, I am going to try it, and see if it sounds better, I'm not saying it will, it's a test, and way to not have to sell my 8 inch, which I happen to like.

It's just a test man, relax, Noone is saying your way isn't the best.

 

[croseiv]

Try it and report back to us....

 

[MADCOW]

I take it you don't think augmenting the mid bass this way will produce any positive audible results either croseiv?

I am going to try it regardless, but I would like to know if everyone is in agreement with what markw implies, that it will be detrimental to the sound even in this instance?

 

[mike c]

i think you should try. i've tried, and i liked it. though it looks like i'm the only one here that believes it's the right thing to do. fortunately, there's no right or wrong in this hobby. it's all about what you want.

because i'm pretty sure i've nailed the 15-80hz range and it's the midbass i want.

 

[highfigh]

But if I'm using my 8 inch is a "mid bass module", won't it be cut off at 60hz anyway?

The cutoff frequency isn't like a brick wall, that's really the -3dB point and if the filter is 12dB/octave, it'll be -12dB at 30Hz but each will affect the other. It's possible to use digital filters that are a lot more steep but there are always phase shift issues. It would be great to be able to set a stopping point for a filter and effectively "stack" speakers in the system, for their best application but it's not that easy.

If you do use it to augment the mid-bass, it'll probably work best if you can actually find out where the main speakers drop off, set the upper limit of the smaller sub to complement that and set the LFE and larger sub to complement where the high pass starts for the smaller woofer. Just be prepared to do a lot of trial and error adjustments- adding drivers will usually add setup complexities. Making a group of speakers work well together requires knowing what each does well or poorly and finding the best way to get them to work together. This will basically involve a series of compromises but if/when you get it to sound the way you really like it, there are usually a few "Oh, yeah!" moments surrounded by feeling like Clyde Crashcup.

Brick wall filters are why people came to hate the original CD players that didn't oversample.

 

[Jack Hammer]

Why ask for opinions and advice if you're just going to discount and ignore what people offer? Why not just try it yourself, which you obviously intended to do regardless of what others thought and then post the results?

Jack

 

[MADCOW]

Thanks Highfigh!

And Jack Hammer, I don't know what the **** you are talking about.

I ask questions to gain understanding, and I always appreciate those who help in that process.

But a certain amount of indoctrination always occurs, and sometimes people whole heartedly beleive in certain things without reason, logic or actual evidence. It takes questions, research, and experiments to indentify when this is happening.

If you think me asking questions for people to further explain what they already stated briefly is "discounting", or "ignoring", then I don't even know what to say to you.