Luke

I hadn't entered some of the specs correctly. After entering them correctly though, the program still suggests a 4.7ft^3 sealed enclosure to achieve the 'ideal' Qtc of 0.707. A little large I think I entered 2.4ft^3 as the enclosure size which achieved a Qtc of 0.78 and F3 of ~38Hz which seems alright. Will it still get low at that F3? Alternatively, I entered 2.1ft^3 as the enclosure size, which achieved a Qtc of 0.909 and Qtc of 38.95Hz. Both with 'typical' damping.

I don't know the specifics but the 18Hz is the free air resonance of the sub. The enclosure will, in a large part, determine the frequency response of the sub.

I just loaded the previous model XXX 15 to compare. I hadn't entered the Bl correctly. It should be half, 9.08 for individual coils and 18.16 for wiring in series. Re should also be halved to 2.1 ohm for individual coils, and 4.2 for wiring in series. This made a huge difference to F3, decreasing it to 38.14Hz in a 2.4ft^3 enclosure, but Qtc is quite low at 0.438, which is less than the sub's Qts of 0.501. Shouldn't Qtc be more than the drivers Qts?

Hey everyone, I posted a thread a while ago about trying to work out the ports for an enclosure for my sub. I've spent alot of time deciding whether or not to go with a ported or sealed enclosure. I've decided to go for a sealed enclosure instead. I've been using Bass Box Pro to try and design an enclosure and I'm getting a bit frustrated Here are the specs of the sub: 15” Electrical Q Value -Qes: 0.58 Mechanical Q Value -Qms: 3.62 Total Speaker Q Value -Qts: 0.501 Free Air Resonance -Fs: 19.10 Hz Equivalent Compliance -Vas: 207.0 liters One-Way, Linear Excursion -Xmax: 54 mm Efficiency -SPL 1W/1m: 85.81 dB SPL Effective Piston Area -Sd: 810 cm^2 DC Resistance -Re: 4.2 ohm Nominal Impedance -Znom: Dual 2 ohm Thermal Power Handling -Pe: 2000 W Force Factor -Bl: 18.16 Mounting Depth - 13.5” Mounting Hole Diameter - 14.5” Overall Diameter - 16” Bolt Hole Circle - 15.25” Motor Width - 10.5” Motor Depth - 5” Basket Depth - 8.5” Displacement - 0.27 cu. ft. Weight - 76 lbs The minimum sealed enclosure size is 1.6ft^3, recommended is 2.1ft^3 and optimum is 2.4ft^3, according to RE. But heres where the problem lies. I will be running the sub in series.....After entering these specs into BBP and selecting 'series' for the 'VC Wiring,' halving the Qes to 0.29, doubling RE to 8.4 ohms, doubling Z to 4 (is that right?), increasing Power sensitivity (dB per watt@1m) by +3dB to 88.61dB, halving the Qts to 0.251 and doubling Bl to 36.32Tm, the program suggests a 0.6ft^3 enclosure. Rather small to say the least.....This achieves a Qtc of 0.707, which is great, but F3 of 71.44Hz, which seems quite high. Have I entered the specs correctly? I've tried changing the damping inside the enclosure without much success. I've entered the only specs given by RE into the program, leaving the other values blank without much of a change. I've entered these same specs and getting the program to calculate the other values also without much of a change. When I entered the standard specs into the program (running seperate coils), I entered 2.4ft^3 as the enclosure size and achieved a Qtc of 0.78 and F3 of 34.06Hz, which seems great, except I won't be wiring the coils seperately Obviously the specs of a driver change when wired in series or parallel, but why is the program suggesting such a small enclosure? And how can I achieve a resonable Qtc while keeping F3 low? Any help with this would be great. Cheers, Luke.

When your car cost you nothing, as long as it fits the 6ft^3 enclosure in the trunk and the SP2150 under the hood. When you feel sorry for the car that cost you nothing, as the panel work, windows, mirrors etc will be no match for 2.5kW. When you spend AUS$600 (and 4 months) to get a sub into the country which no body else has because you have to have the best. When you have 800WRMS powering an RE '06 XXX15 in your room the size of a milk carton.

Awesome! I think I've finally figured it all out. Now I just need to build another enclosure for SPL I can't be bothered messing around with replacable ports. That'll probably come later on.... Thanks everyone for your help. I'll post some pics when its eventually done

The "add half the port width" is to determine the effective port length given the physical port length. If you are calculating what the port should be, the equation gives you the effective length and you subtract half the width to get the physical length that you need to build. This only applies to slot ports where one of the port sides continues past the opening of the port. If you're using round ports, this is totally irrelevant. For figuring flared ports http://www.subwoofertools.com/forum/flare.htm that calculator should give you what you need. To figure the flare radius measure the overall diameter of the flare, sbtract the diameter of the tube and divide by two. Should be 'net' not 'gross.'That caluculator makes it so easy. I put the following figures into the calculator: Box volume: 5.5ft^3 Tuning frequency: 33Hz Tube diameter: 6" Number of ports: 2 Flare radius: 1.5" (?) - With the 6" ports flared to 9", is that right? Coming up with a length of 26.125" (without flares) and an overall length of 29.125" (with flares). When it says "Box Volume," does this mean "net volume" or "gross volume?" I calculated the driver displacement and port (internal) displacement to be 0.437331ft^3 in total. Does this mean I should build a 5.9ft^3 enclosure?

Thanks for the link, its a good read! I did it properly this time. I came up with a port length of just under 7.5inches for each port. Does that seem a bit short?

Thanks for the reply I'm pretty sure I worked it out but the numbers are: LV Port length = 5.61737957^14 inches Av Port area = 56.54866776in^2 Vb Gross air space = 10368in^3 Fb = 33 I'm pretty sure that port length equates to 14.268144cm. That sounds about right but does that mean because I have two ports, they should be half that length each?

Hey everyone, I'm having issues designing an all purpose (SQ while being loud) ported enclosure for my RE '06 XXX15 sub. I had a ported enclosure built. Its approx. 3.5ft^3. It has a rectangular L port with a port area of 60in^2. At the time when I designed the enclosure, I hadn't discovered WinISD or any other similar programs and just used the RE L Port calculator. This enclosure was supposed to be tuned to 35Hz. In short, its a mess. There is alot of port noise and it barely reporoduces anything under 35Hz. So I went back to the drawing board and learnt how to use WinISD. From what the program is telling me, it can't be tuned to 33Hz (which I want to achieve) unless the enclosure is about 11ft^3 I'm planning on using 2 6" aeroports (or PVC pipe ). Basically the absolute maximum sized enclosure I can have is 6.5ft^3. On WinISD, if I put in a 6.5ft^3 enclosure tuned the 33Hz with 2 6" round ports, the gain on the graph shows that it will peak at around 38-40Hz. My question is, is there a way I can achieve a tuning frequency of 33Hz in a 6.5ft^3 enclosure or smaller with as little port noise as possible? Keeping in mind, this sub moves a truck load of air. I'm probably going to have to compromise somewhere but I was hoping this might be possible Cheers!

This site is dedicated to speaker excusion. You can download video's of different brand subs going nuts (Check out the JL W7). Real Of Excursion Vids This site also has some sweet links to some really helpful sites with tutorials, test tones, wiring options etc. Enjoy Realm Of Excusion Links

Thats tite! Good job with the enclosure

www.realmofexcursion.com had a link to this site. I got the realm of excusion link from an australian forum. I like it here, nice and small

Like you guys said, it would definately be cheaper to do it yourself. But if you bought a PC from Alienware, the hardware and software would be set-up real good. It would probably be a little faster.

What tracks/songs/albums are great to test - SQ and - SPL on a kick ass system? I mostly listen to Urban and Dance. Here are some of my favourites for SPL: - Pretty much anything by Lil Jon - Petey Pablo - Freek a leek - Petey Pablo - Vibrate (the video clip is awesome ) - Lil Flip - Gameover - Ashanti - Only you - Ciara featuring Petey Pablo - Goodies - Fat Joe featuring Lil Jon, Eminem and Mase - Lean Back (remix) - Ludacris - Saturday The system I own isn't very good for SQ to say the least I can't really think of any good songs for SQ.