Different size and brands of subs

[bkolfo4]

So I keep seeing people post on here that using 2 different size subs, or two different brands will not work. . .

The reasoning is normally "you will get cancelations".

I have run multiple sub sizes before with good results, and I really don't see why 2 different subs playing the same frequency are going to cancel each other. I see that as 2 sources added together. If multiple people in a choir sing the same note, doesn't it get louder? Their voices are not exactly the same.

To be clear - I am not saying this is my favorite thing to do!!!! There really is no reason for it. I have customers call all the time wanting to buy (2) 10" and (1) 18" because "They want to get the lows and the highs". I have to explain that the size of the sub is not always going to determine how low it will play. There are 10's that play low, and there are 18's that don't. Box design and driver parameters will decide how it will perform.

So, today I did a little experiment. (1) 10" Chaos and (1) 12" MTX shallow mount, and an AQ2200D.

To perform the test:

I ran three conditions - just the 10", then just the 12", then both.

I maintained the same voltage on the speaker output of the amp for all 3 conditions (used 50 Hz to measure to output voltage)

I measured output from 30 to 50 Hz in 2 Hz increments.

The 10" was in .6 cuft sealed without stuffing, the 12" was in .7 cuft sealed with 12 oz of polyfill.

The results:

Freq (Hz) 10" Chaos 12" MTX Both

30 90 95 96

32 95 96 97

34 95 96 97

36 95 96 97

38 95 96 97

40 95 96 97

42 95 96 97

44 95 96 97

46 95 96 97

48 95 96 97

50 95 96 97

I also played several songs that I am very familiar with in my truck on the MTX 12". I played these songs with both the 10" and the 12" playing together. While it was not much louder, there definitely were no issues. Bass was clean and strong. No missing notes, etc.

I also want to point out - You can always have issues with cancellations, but you can have those issues with 2 of the same sub. Having the subs as close together as possible and facing the same direction will normally minimize or eliminate the issue.

I know some people are not going to like this, but I think a lot of people just jump to conclusions because it is what they have read or heard. What's new. . .

Brian

Edited April 16, 2012 by bkolfo4

[jrchevy87]

I agree but I have to point out do NOT put two different subs the same box without a divider. I know most of is know this but I figured I'd put that out there for anyone that took that to mean u can use different subs in the same airspace

[TeamHT]

Spoilers on FWD vehicles that never see the track still provide downforce....but it's still rice. I see it as such a ghetto image, regardless of the performance. I am not one of those people who says it won't work because of cancellation, but it just looks so shoddy to me.

And not to disprove your results, but wouldn't the missing vital information be testing two 10"s instead of a 10" and a 12" to accurately prove/disprove the notion?

Edited April 16, 2012 by TeamHT

[Quiet]

You can put whatever combination of subs in your car that you want.

That being said, people that do so usually don't know what they're doing. I don't know who came up with the cancellation theory, but it's BS.

Some subs will peak at higher freqs than others. Having two different (or more) subs producing the same tones will be harder to tune for. It's easier to control the tonal balance in your system the fewer factors you have to change.

[bkolfo4]

And not to disprove your results, but wouldn't the missing vital information be testing two 10"s instead of a 10" and a 12" to accurately prove/disprove the notion?

I only had the ability to run the test with these subs without building something. Did not feel like building anything.

I see the 'issue' being discussed with different size subs and with different brands. I though two different size subs that were also different brands would kill two birds with one stone. . .

[TeamHT]

Yeah, I can see that. But to actually prove/disprove the notion, especially about cancellation, the standard I would think be two 10"s. Then if mixing the 10" and a 12" yielded different results, would that be lower...higher?

Not pushing, just bouncing ideas. I thought about doing it but man, it would need some building to test every aspect and at the moment I don't have that kind of time so my hat off to you for this.

[bkolfo4]

I see what you are saying. Two 10's vs. one 10 and one 12" - what is the difference

I was mainly just going for the different brand, different size has a negative effect theory.

I have several chaos 10's and 3 other brands of 10's, along with 2 different 12's. Maybe next time I am building a box, I will throw together a quick test box.

Brian

[TeamHT]

I will definitely be tuned in, it would be interesting to see. But then I wonder if on a small daily scale would there even be a difference? Let alone an audible one, cancellation may occur but not one measurable enough.

Take Techforce's two 18"s and two 15"s. I wonder if a single enclosure built for four 15"s would have yielded higher scores, better listening, or even less rolloff.

Appreciate the information here though

[Omega5002]

Your topic reminds of my friend who wants to put 2 Jl W7 8's, 10's, and 12's in his car to achieve better sound quality somehow.

I think the different sub size theory would actually work if each different sub plays different frequencies. That's my point of view, but I could be wrong, but I'd like to see where this topic goes.

[bkolfo4]

Your topic reminds of my friend who wants to put 2 Jl W7 8's, 10's, and 12's in his car to achieve better sound quality somehow.

I think the different sub size theory would actually work if each different sub plays different frequencies. That's my point of view, but I could be wrong, but I'd like to see where this topic goes.

When you start talking different frequencies, then it is more like a 3 way or 4 way setup. No issue there, except you want to get drivers that have the right parameters to play in the range that you want them to. I would not buy an 18" for low bass, and then a 12" of the same sub for midbass. . .