[Paul Spencer]
VALUE: it's more than just the cost of the parts!
Getting the best value for money is more than just getting good prices. It's also making wise choices and understanding how different decisions affect each other.
Disclaimer: The focus in this page is on bang for buck. There are other factors beyond the scope of this article. You should consider this advice in conjunction with advice from other sources, including other wiki pages.
| SYNERGY: A phenomenon which occurs when the total effect exceeds the sum of the individual parts |
Q: which driver is better bang for buck, driver A which has an xmax of 12mm for $200 or driver B with 24mm of xmax for $250?
A: impossible to say as it depends on other factors; if the lower xmax driver works well in a vented box, it may give you more value than the higher xmax driver which may require passive radiators. By the time you allow for the cost of the passive radiators, you could almost buy a second driver.
You should consider the total project. Come up with a design and look at the total cost and performance. Then come up with a different version and compare the cost and simulated performance. A driver may appear to be a bargain, until you discover that it requires a lot of power to achieve its performance potential.
Tips on getting the most sub for your money
- bigger is better - all other things being equal, a 15" driver and a big box is a good place to start
- pro amps often have more power for the money than plate amps when you want more than 350w or more than one channel
- a vented sub can match the SPL of two sealed subs using the same driver with half the power required
- if your "sub" only needs 40 Hz extension then a bass horn with an 8" high excursion driver can show up much more expensive 12" or 15" drivers conventionally loaded, but it will be big!
Worked example: what's the cheapest way to get 120 dB @ 25 Hz?
(currency: $US)
1. First let's see what it takes to do it with a vented subwoofer.
a) Dayton Quattro 15" - 250L tuned @ 22 Hz x 3 subs required - 200w each
Driver: $86 x 3
Amp: $400 - 1000w Dayton plate amp
Total: ~$700
b) Dayton DVC 15" - 250L tuned @ 22 Hz x 2 subs required - 300w each
Driver: $128 x 2
Amp: $250 - Behringer Europower EP1500
Total: ~$500
Note: a crossover will need to be included
c) Acoustic Elegance AV15 - 200L tuned @ 20 Hz - 2 with 500w each.
Driver: $180 x 2
Amp: $300 - Behringer Europower EP2500
Total: ~$660
Note: a crossover will need to be included
d) Exodus Audio CX-15 - 250L tuned @ 20 Hz - 2 with 350w each.
Driver: $185 x 2
Amp: $149 x 2 Rythmik Audio 350w plate amp
Total: ~$670
2. Now let's try to do it with a passive radiator sub
Passive radiators - Acoustic Elegance - PR15 for $45 or PR18 for $125
For any of the above subs you would need four of the PR15 for each 15" driver or two of the PR18.
1a)$700
2a)$970 (6 x PR15)
This would be a silly choice since a low xmax driver in a large box won't have vent noise issues.
1b)$500+
2b)$1000+ (4 x PR18)
or $770+ (6 x PR15)
The cost has now doubled! This sub could easily work as a vented sub without serious vent issues, although it is still more of a challenge than the Quattro. The price is not so bad if you use the smaller PRs.
1c)$660+
2c)$1160+ (4 x PR18)
No doubt the PRs will be impressive-looking, but the cost is now getting high. This sub will have more headroom, although to gain use of the extra output without PRs requires a seriously designed vent!
1d)$670
2d)$1170 (4 x PR18)
3. Now let's attempt to do it with a sealed or IB sub!
Acoustic Elegance IB15
6 drivers required ~ 200w each
Drivers: $100 x 6
Amp: $250 - Behringer Europower EP1500
Total: ~$850
This is cheaper than most of the PR subs! This is an IB setup, where there is a very good deal going for the driver. With the drivers chosen for the vented subs, the cost would be up to twice as much since you would need twice the number of subs and twice the power. The only economy of scale here comes in using pro amps in place of smaller plate amps. If we were to use 12" drivers here, the cost would also be more since they require as much power (read same amp cost) but are less efficient.
