Making the most out of the power and available airspace!?

[Triticum Agricolam]

Ok, so when comparing four subs vs eight.  Lets assume you are using the same subs.  Lets assume you have four 10" subs in a 6 cubic foot box vs eight 10" subs in a 12 cubic foot box.  Tuning is the same. Your four subs are D2 coils so you can wire them to 1 ohm at the amp, your eight subs are D4 coils so they are also wired to 1 ohm load at the amp.  Other than that the subs are identical.  The setup with eight subs SHOULD be about 3 db louder because you have twice the cone are AND twice the box volume.  In practice it probably won't be exactly 3 db louder, but it should be somewhere in that area.  

Now you were talking about using different subs in your "four vs eight" comparison.  With different subs things are...different.  Generally speaking lower power subs tend to be more efficient due to their lower moving mass, there are exceptions though.  This would PROBABLY shift the advantage even more towards the eight sub setup.

You are making an error in your cone area calculations.  The problem is the radiating area of a sub isn't the same as it nominal diameter.  A 10" sub has a cone that is more like around 8-1/8" in diameter, there is some variance between different models of subs.  At 15" sub has a cone that is around 12-3/4" in diameter.  So when you are comparing cone area between different sized subs, here are the numbers that are more accurate:

8" sub = 32.5 sq in

10" sub = 48 sq in

12" sub = 79 sq in

15" sub = 125 sq in

18" sub = 188 sq in

Not all subs are exactly the same, depending on the size of the surround there is going to be some variance between different models of subs with the same nominal size, but those numbers will give you a lot more accurate comparison.

[Joe X]

3 hours ago, Chase Wallace said:

Joe X, I've tried that before lol. My question is pretty general. You could look at it like this. Will 1-10 with 1000 watts be just as loud as 2-10's with 500 watts each?

The actual situation is that I'm thinking of using 8 Sundown EV3 10's given 4000 watts, 500 watts each or 4 Sundown SA-10v3's given 4000 watts for 1000 watts each. The boxes would be built to the correct specs for both. I would love to save the space and use 4 but I can give up some more space and fit 8 if that would be louder which I think the extra cone area would be louder with 8.

 

Modeling is the best way to answer specific questions so take a look:

 

Red:       1 x E10v3, 1.0@32Hz PA:16 square inches. 500W power.

Yellow:   2 x E10v3, 2.0@32Hz PA:32 square inches. 500W power EACH so 1000W power total.

Orange:  1 x E15v3, 3.25@32Hz PA:52 square inches. 500W power.

 

 

As you can see in this case two 10s can in fact match the single 15 projected output but at a higher cost, you need to pay for two drivers and have an amp (and electrical) twice as powerful. The upside of the two 10s is that you needed 2 cubic feet net instead of 3.25 to match output, so space is saved going that route.

 

[Chase Wallace]

2 minutes ago, 3vil said:

I'm not implying that I have the answers for you. More to the point, I'm curious  to learn more in this subject myself. I feel that realistically, testing is the only way to get definitive answers for your vehicle.

Fair enough, I wish I had the money to test different setups to figure out what works best but I've been saving and trying to catch sales for about a year now for my future system. My mother actually told me that she would help me with the cost as a Christmas present after taking care of her last summer when she was in the hospital for a few months. Unfortunately her husband lost his job and she hasn't been able to help me. I've already spent enough money on this project that I feel I have to finish it even though I'm way over the original budget I had in mind. I still want to eventually finish it though. For my income the subwoofers are a huge expense. I'm trying to get the best bang for the buck. In other words my thinking is that if I'm going to spend what I consider a crazy amount of money then I want to make sure that I'm not disappointed with the results. I want something pretty extreme by most peoples opinion. I know there are a lot of guys on here that would probably laugh at me for saying what I have in mind is extreme but for someone like me this is going to be the biggest and most expensive system I've ever done. Call it a poor guy trying to build his dream system. I can't afford to make the wrong choice's and end up spending 1/4 of my yearly income on something that I'm not satisfied with. I've even been considering cutting the back cab out to get the air space for 4-18's which is what I really want. I've narrowed down the options that wouldn't require cutting the cab. I've already spent a lot of time figuring out what I could actually fit with the airspace I have and factoring in things like port surface area and physical location. The options that I think I can make work would be 8-10's, two 15's, or anything that requires less air space and port area. If I remember right I have at most 10-12 cubic feet total to work with but that's pushing it and it would be much better if I could get away with using something closer to 8-9 cubic feet. I could even use more than 10-12 cubic feet at the expense of seating area but I'm trying to keep most of the seating and avoid cutting the truck. To be clear on how I would get that much space is to build the box itself as a back seat in the extended cab truck. By removing the back seat and using the box itself as the seat I'm able to get a lot more space than I would be able to do with the factory seat installed. I also plan on running the box from the middle of the back seat all the way up the center of the truck to the dash and I can make the console part taller or shorter to dial in the air space requirements. Of course I don't want to build the center console area of the box up too high. Something along the lines of a comfortable arm rest location would be about as high as I would want to go with it. Still that should explain how I'm coming up with such a large air space instead of just trying to make something fit hidden under the back seat.

The truck is a 2000 Chevy 1500 extended cab for anyone who's wanting to know. I have a Twisted Sounds 3.5k that tested over 4800 RMS certified and 5000 uncertified so that's what I will be working with to power whatever setup I use.

 

[Chase Wallace]

56 minutes ago, Triticum Agricolam said:

Ok, so when comparing four subs vs eight.  Lets assume you are using the same subs.  Lets assume you have four 10" subs in a 6 cubic foot box vs eight 10" subs in a 12 cubic foot box.  Tuning is the same. Your four subs are D2 coils so you can wire them to 1 ohm at the amp, your eight subs are D4 coils so they are also wired to 1 ohm load at the amp.  Other than that the subs are identical.  The setup with eight subs SHOULD be about 3 db louder because you have twice the cone are AND twice the box volume.  In practice it probably won't be exactly 3 db louder, but it should be somewhere in that area.  

Now you were talking about using different subs in your "four vs eight" comparison.  With different subs things are...different.  Generally speaking lower power subs tend to be more efficient due to their lower moving mass, there are exceptions though.  This would PROBABLY shift the advantage even more towards the eight sub setup.

You are making an error in your cone area calculations.  The problem is the radiating area of a sub isn't the same as it nominal diameter.  A 10" sub has a cone that is more like around 8-1/8" in diameter, there is some variance between different models of subs.  At 15" sub has a cone that is around 12-3/4" in diameter.  So when you are comparing cone area between different sized subs, here are the numbers that are more accurate:

8" sub = 32.5 sq in

10" sub = 48 sq in

12" sub = 79 sq in

15" sub = 125 sq in

18" sub = 188 sq in

Not all subs are exactly the same, depending on the size of the surround there is going to be some variance between different models of subs with the same nominal size, but those numbers will give you a lot more accurate comparison.

Trit , Thanks for the reply. You helped me a lot with my questions the last time. I already knew about what you're saying with calculating the cone area and there being slight difference between the same size subs. To make things simple I was just going off the cone size charts that you can google and find. I realize it's not accurate but I think it still helps when seeing which size and number of subs gives roughly the same amount of surface area. Maybe I should make my own chart using the more realistic numbers you quoted but I figured the other would be enough to compare and contrast different numbers and sizes.

As far as the 4 subs vs 8 subs comparison that you gave, that was exactly what I was thinking. Also if I understand right having more voice coils helps with coil impedance rise. I was told this by another member anyway.

[06RTCharger]

Since u really want four 18s, why not start with one? Have a big ass 18 in the back. Then later you can get another same 18, then build another box for 2 18s. And progress like that. That way u dont waste subs. I'll say that seeing an 18inch sub in someones truck is WAY more impressive than a few 10s in my opinion. 10s can still get way down, but just visually.....18's. Thats just my personal thoughts tho. Ive only seen an 18 once in my life and that was a single, shit slammed the windows off (literally) of the lil oldschool 80s hatch camery (i think). 

[Chase Wallace]

41 minutes ago, Joe X said:

 

Modeling is the best way to answer specific questions so take a look:

 

Red:       1 x E10v3, 1.0@32Hz PA:16 square inches. 500W power.

Yellow:   2 x E10v3, 2.0@32Hz PA:32 square inches. 500W power EACH so 1000W power total.

Orange:  1 x E15v3, 3.25@32Hz PA:52 square inches. 500W power.

 

 

As you can see in this case two 10s can in fact match the single 15 projected output but at a higher cost, you need to pay for two drivers and have an amp (and electrical) twice as powerful. The upside of the two 10s is that you needed 2 cubic feet net instead of 3.25 to match output, so space is saved going that route.

 

Can you tell me where I can download the program you used and what it's called? The 8 EV3 10's would actually be cheaper than say 4 SAv3 10's or two Sundown Xv2 15's or even more expensive series. I know normally its more cost effective to use less subwoofers but this is an oddball case of being able to get 2 EV3's for less than 1 SAv3 so it's actually cheaper to use twice as many of the lower cost subs. Box and port size are the negitive side of using twice as many and that's why I'm really wanting to know if it's worth loosing the cab space. If it's cheaper and louder then it might be worth the space loss.

[Triticum Agricolam]

10 minutes ago, Chase Wallace said:

Trit , Thanks for the reply. You helped me a lot with my questions the last time. I already knew about what you're saying with calculating the cone area and there being slight difference between the same size subs. To make things simple I was just going off the cone size charts that you can google and find. I realize it's not accurate but I think it still helps when seeing which size and number of subs gives roughly the same amount of surface area. Maybe I should make my own chart using the more realistic numbers you quoted but I figured the other would be enough to compare and contrast different numbers and sizes.

As far as the 4 subs vs 8 subs comparison that you gave, that was exactly what I was thinking. Also if I understand right having more voice coils helps with coil impedance rise. I was told this by another member anyway.

More voice coils helps reduce power compression, which raises impedance.  But its not just as simple as "more voice coils are better".  

FYI, the software Joe X is using is BassBox Pro.  Its costs money, but you can download WinISD for free and it pretty similar.  

My suggestion based on the space you have available, I'd be looking at running four 12"s.  I know the eight 10"s has more cone area, but cone area isn't everything.  I have a single E-10 in a tapped horn box that has about the same efficiency as a single 15".  The box takes up as much space as a box for a 15" would though.  IMHO, while cone area can be important, box size is king.  

If you are looking to save some money, the Sundown Yard Sale is going on right now.  Just google "sundown yard sale".  

[Chase Wallace]

10 minutes ago, 06RTCharger said:

Since u really want four 18s, why not start with one? Have a big ass 18 in the back. Then later you can get another same 18, then build another box for 2 18s. And progress like that. That way u dont waste subs. I'll say that seeing an 18inch sub in someones truck is WAY more impressive than a few 10s in my opinion. 10s can still get way down, but just visually.....18's. Thats just my personal thoughts tho. Ive only seen an 18 once in my life and that was a single, shit slammed the windows off (literally) of the lil oldschool 80s hatch camery (i think). 

Well the problem with that is where to fit an 18" sub. I think a 15" is about the biggest I can fit anywhere without giving up another seat. Two 18's also require more air space and port area than eight 10's. The two 18's would also have less cone area. As far as looking cool goes, the subs will be down firing towards the floor so nothing will be visible which makes it pointless to base the decision on what would look cooler. No one will see the subs after they're installed.

[Chase Wallace]

4 minutes ago, Triticum Agricolam said:

More voice coils helps reduce power compression, which raises impedance.  But its not just as simple as "more voice coils are better".  

FYI, the software Joe X is using is BassBox Pro.  Its costs money, but you can download WinISD for free and it pretty similar.  

My suggestion based on the space you have available, I'd be looking at running four 12"s.  I know the eight 10"s has more cone area, but cone area isn't everything.  I have a single E-10 in a tapped horn box that has about the same efficiency as a single 15".  The box takes up as much space as a box for a 15" would though.  IMHO, while cone area can be important, box size is king.  

If you are looking to save some money, the Sundown Yard Sale is going on right now.  Just google "sundown yard sale".  

Nothing can ever just be that simple right? lol

I have been using WinISD but I never realized you could overlay multiple subs on the graph like that. I think I've looked at BassBox Pro and it was expensive "to me" if I recall correctly. I wish I had it as well though.

Four 12's was the original plan when I decided to start collecting parts for this build. I've just moved more towards asking the question of how much cone area can I actually get and have everything fit in the space and shape of the box. I thought cone area was king but I trust your opinion over mine. I've played around on WinISD adding box size and been able to get as high as a 9-10 db increase from increasing the box size and port frequency so what you're saying does seem logical.

Thanks for the yard sale tip! Since I planned to down fire all the subs I had planned to use B-Stock from CAB 87$ for an EV3 10. I'll check the yard sale and see if the prices are even cheaper than B-stock prices.

[Joe X]

29 minutes ago, Chase Wallace said:

Can you tell me where I can download the program you used and what it's called? The 8 EV3 10's would actually be cheaper than say 4 SAv3 10's or two Sundown Xv2 15's or even more expensive series. I know normally its more cost effective to use less subwoofers but this is an oddball case of being able to get 2 EV3's for less than 1 SAv3 so it's actually cheaper to use twice as many of the lower cost subs. Box and port size are the negitive side of using twice as many and that's why I'm really wanting to know if it's worth loosing the cab space. If it's cheaper and louder then it might be worth the space loss.

It's bass box pro but it's commercial, what I pointed out at the end is that you can actually save space (1.25 net) going with two 10s rather than one 15 and get the same output.