Best value for US$250 in US- 4 Dayton Classic 15"?

[bigjon]

After much thought and considerable research (thanks mostly to this forum) I have all but decided to go with 4 of the Dayton Classic DCS380-4 drivers instead of 2 MJ-18 drivers from Mach5. With shipping to the US the price for either comes to $250 (due to $103 shipping from Mach5 in Canada for 2 drivers vs free shipping and volume discount for 4 drivers from Parts Express). I have not seen this particlar Dayton driver recommended here, but the T/S parameters seem to check out for IB use. Just wanted some expert advice to be sure my theory is intact.

First, here are the T/S parameters for each driver - note that I am looking for a 4ohm system load, hence my choice for 8ohm MJ-18s:

PE DAYTON DCS380-4 CLASSIC 15" SUBWOOFER 4 OHM
www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-470
4 ohms
Fs: 20 Hz
SPL: 92 dB 2.83V/1m
Vas: 9.70 cu. ft.
Qms: 4.00
Qes: .50
Qts: .44
Xmax: 8.5 mm

Mach5 18" High Power Woofer - 8ohm version
www.mach5audio.com/product_info.php?products_id=38
Fs = 30.4 Hz
Qt = 0.35
Qes = 0.39
Qms = 3.41
Rms = 12.3
Cms = 0.100 mm/N
Vas = 243.8 liters
Sd= 1029.2 cm2
Xmax = 12mm

Fs and Qts are superior for IB use with the Dayton drivers (I do not yet have an EQ). I realize the Dayton's Xmax is sub-par at 8.5mm, but assuming an Sd the same as the PE IB (819 cm2), I calculate a Vd of 1.3923 liters compared to the MJ-18's 2.4696. With 4 drivers the Daytons would yield total system Vd of 5.5692 compared to 4.9392 for two MJ-18's.

Factoring in the (slightly) superior Vd, efficiency boost for greater number of drivers, lower Fs (20hz vs 30.4hz), and slightly higher Qts (.44 vs .35), the 15s appear to be a better route for me to take. Considering the 15s can be had for US$62.40 with free shipping this seems like a steal to me.

Any comments or suggestions?

[mcwhorter]

I believe Mach5 Audio has found a US Distributer to help offset the $100 shipping costs. I don't know when that relationship is scheduled to start.

Waiting for a US distributer would certainly save some cash on shipping.

[mrogowski]

Hi Jon,

It all comes down to displacement. If you get more displacement going with the 4 Daytons verses the 2 MJ's I say go for it!

Curious tho, if you can fit 4 15" units into your setup, can you not also fit 4 18" units?

SSA should have their shipment of MJ-18's by the end of January.

Merry Christmas!
Mark

[bigjon]

Hi Mark, do you expect the price for the MJ-18 to remain similar when purchased from SSA? I had seen prior posts regarding a possible US distributor but did not realize how soon that was going to happen.

[ryans]

There's not many IB subs with less than 6 liters of total displacement. A typical install is closer to twice that. So I'm thinking the smart move, if you're really concerned with cost, is to go with a pair of Mach5 18's but build the manifold so that it can easily expand to hold an additional pair.

Much easier to add 2 more 18's if necessary than to add 4 more 15's.

[ThomasW]

2- PE IB15"s are a better choice than 4 of the Dayton Classics.

[bigjon]

Good points - I'll put off buying drivers until Mark has a US distributer, then buy a couple MJ-18s as originally planned, but with a manifold large enough for 4. I'm hoping the smallish size of my room (2000 cubic feet) will allow 2 drivers to be sufficient, but we all know sufficiency is the only unobtainable when it comes to HT. ;D

I'm still going to take advantage of the Parts Express free shipping deal (going on until January 4 I believe) and snag a BFD 1124 while they are still available. That should help with the house curve.

Thanks everybody for all your help - I'll post pictures once I've broken ground on this project. Merry Christmas!

[mrogowski]

Hope everyone enjoyed their Xmas...

Hi Jon,

That's the idea. Costs of raw materials are going up in Asia so it is difficult to say how long I can keep things at that price level. Shouldn't have an effect on you tho if you plan to purchase right away...

Best regards,
Mark