What do you mean MemX? How do you know it's £150. (help me) 😀
150.00 GBP = 252.466 USD
150.00 GBP = 184.265 EUR
1. You need a company/distributor that ships worldwide (EU/UK in this case)
2. You need to pay the price* of the driver
3. You need to pay the price for transport overseas
4. You need to pay customs (EU/UK, or where it applies)
5. You need to pay 24% VAT (EU).
Stereo Integrity's SI HT 18" D2/D4 *(pre-order purchase price: $162.00)
Stereo Integrity | Order Online
If you contact Nick at SI, he can confirm expected manufacturing dates and availability of the 18s. I think they are all out of stock at the moment.
If you want to order, ask him for a price for shipping to your address. He can be (very) slow, but give him a few days between chase emails (and put up a post on AVS saying you are waiting if you don't get a response in a couple of weeks! 😉) and he will sort you out 🙂
I can't remember the exact split between driver cost, shipping cost and VAT (I don't think there is a customs charge for drivers coming into the UK) but IIRC it is about $1000 in total for a 4-driver order, which is roughly £600, or £150 per driver (or thereabouts!)
If you want to order, ask him for a price for shipping to your address. He can be (very) slow, but give him a few days between chase emails (and put up a post on AVS saying you are waiting if you don't get a response in a couple of weeks! 😉) and he will sort you out 🙂
I can't remember the exact split between driver cost, shipping cost and VAT (I don't think there is a customs charge for drivers coming into the UK) but IIRC it is about $1000 in total for a 4-driver order, which is roughly £600, or £150 per driver (or thereabouts!)
The SI woofers looks completely the wrong thiele small parameters for a DJ or music subwoofer. Looks more for getting very low in large sealed enclosures, plus the cone is 418g I can't imagine the power requirements!
Many people will write me off as a nut for suggesting this, but weirdly for a 35-40Hz subwoofer, multiple MCM 55-2421s seem to work out well if you're in the USA (which I'm not) and don't have to pay shipping. With 6 of them being a replacement for a Faital Pro 15HP 1030/1060 both in box size, tuning and total output (roughly one for every 15l at 40Hz). I'm not sure of the durability of those drivers though. I've found for a 40Hz box, Fs/Qts = 120 works well, with higher numbers meaning higher tunings and vice versa.
I need to start an article on driver equivalence, I've some interesting findings on Thiele Small Parameter maths that came to me as I thought about what thiele small parameters change with isobaric loading, studying n pairs of n isobaric drivers, and also changing n to non-whole numbers. The maths is largely theoretical but it is useful for determining sizes of vented boxes, and width scaleable horn designs.
Many people will write me off as a nut for suggesting this, but weirdly for a 35-40Hz subwoofer, multiple MCM 55-2421s seem to work out well if you're in the USA (which I'm not) and don't have to pay shipping. With 6 of them being a replacement for a Faital Pro 15HP 1030/1060 both in box size, tuning and total output (roughly one for every 15l at 40Hz). I'm not sure of the durability of those drivers though. I've found for a 40Hz box, Fs/Qts = 120 works well, with higher numbers meaning higher tunings and vice versa.
I need to start an article on driver equivalence, I've some interesting findings on Thiele Small Parameter maths that came to me as I thought about what thiele small parameters change with isobaric loading, studying n pairs of n isobaric drivers, and also changing n to non-whole numbers. The maths is largely theoretical but it is useful for determining sizes of vented boxes, and width scaleable horn designs.
That sounds far more complex than my noob understanding 😛 so I will look forward to reading it 🙂
The SI drivers are rated officially at 600wRMS, so not too high-power, I thought? Although I am noob and still have lots to learn! They are being run in AVSForum builds (and hopefully my own living room soon!) in 3.5-4cuft boxes with up to double that (although, of course, only drawing that when reproducing <20Hz film soundtrack bass levels) and I believe the suspension is soft enough to enable them to be run IB with a lot less power.
The SI drivers are rated officially at 600wRMS, so not too high-power, I thought? Although I am noob and still have lots to learn! They are being run in AVSForum builds (and hopefully my own living room soon!) in 3.5-4cuft boxes with up to double that (although, of course, only drawing that when reproducing <20Hz film soundtrack bass levels) and I believe the suspension is soft enough to enable them to be run IB with a lot less power.
Since one 18" has about the same surface area as two 12" you could just use 2 Lab12 (around £140 ea from here:LAB 12) or two BMS 12S330 from here:BMS 12S330
I forgot to mention this is meant for DJ/PA use above 35Hz, although no reason why it can't be used for home stereo.
I wouldn't bother using the Lab drivers outside of some sort of horn (Tuba, Lab, Inlow sound etc). Too expensive relative to displacement, and the cones are too heavy (relative to surface area) for BR use (other than car/HT). It has almost as high an Mmd as the P Audio woofers despite being a 12 vs an 18.
After being a massive horn fan for a long time, believing BR to be power guzzling, but they are not as bad as I thought. Size for size, they can hold their own and a few comparisons I've found they can often exceed the efficiency of equivalently sized horns in the lower registers.
The thing they lose badly to horns on is 'displacement efficiency' so you won't necessarily use more amp power but you may spend more money on drive units, and they want different drivers. Grouping any speaker combination increases the efficiency. Horns have the LF efficiency boosted in groups, while it seems groups of already flat BRs have the overall tuning lowered and use up displacement even faster!
The enclosure is really a sort of gear box, where the horn is like a taller gear and vented is like a lower gear. So 'high torque' drivers like a Sundown SA8 or Lab 12 in a BR is a poor match, like a cyclist spinning madly along the flat in 1st gear, or inflating an air bed with a cycle pump.
Or horn loading the P-Audio E18 600s is like the cyclist straining uphill in a high gear, or trying to pump bike tyres to high pressure with an air bed pump!
I wouldn't bother using the Lab drivers outside of some sort of horn (Tuba, Lab, Inlow sound etc). Too expensive relative to displacement, and the cones are too heavy (relative to surface area) for BR use (other than car/HT). It has almost as high an Mmd as the P Audio woofers despite being a 12 vs an 18.
After being a massive horn fan for a long time, believing BR to be power guzzling, but they are not as bad as I thought. Size for size, they can hold their own and a few comparisons I've found they can often exceed the efficiency of equivalently sized horns in the lower registers.
The thing they lose badly to horns on is 'displacement efficiency' so you won't necessarily use more amp power but you may spend more money on drive units, and they want different drivers. Grouping any speaker combination increases the efficiency. Horns have the LF efficiency boosted in groups, while it seems groups of already flat BRs have the overall tuning lowered and use up displacement even faster!
The enclosure is really a sort of gear box, where the horn is like a taller gear and vented is like a lower gear. So 'high torque' drivers like a Sundown SA8 or Lab 12 in a BR is a poor match, like a cyclist spinning madly along the flat in 1st gear, or inflating an air bed with a cycle pump.
Or horn loading the P-Audio E18 600s is like the cyclist straining uphill in a high gear, or trying to pump bike tyres to high pressure with an air bed pump!
vented enclosures have the most output for the space. this is widely accepted. generally it can take as many as twice the drivers and twice the amp power to achieve this though.
I've achieved flat responses in hornresp as high as 104-105dB 2.83V 1m from 40Hz up. On a parallel wired dual 15/18. Dual Kappalite 3015lf or B&C 18TBX100 in 13.2 cubic feet internal tuned to 41Hz.
Martin Audio Professional Loudspeaker Systems ? Unite Your Audience claims 105dB sensitivity with no SPL chart though I found that's possible in theory.
Corner load said cab and you're not far off horn territory. About 115dB sensitivity in a corner, same as John Inlow's version of the Lab Sub but smaller.
I did a rough comparison of two of the P-Audio design above (before down sizing) vs the dual 12 T60 both in corner.
The T60 was A: bigger, B: got lower (25Hz vs just below 30), C: Handled more power (50V vs 35V) D: Used more expensive drivers
The P-Audio was a bit more sensitive between 30 and 40Hz if I recall, but not much in it. I concluded horns only had an advantage if they were bigger.
As such, it seems a small horn cab like the 24" wide T24 has no advantage over a single 15/18 reflex by itself. Judging only by the provided charts it seems to be considerably LESS efficient than a 3015lf in a box of the same external dimensions with sensitivity drooping into the lower 90s instead of a flat 98-99. Considering it's advertised as having a 9dB sensitivity rating over a 1x18 by itself (100 watts outpower an 18 with 800). Though more efficient at reproducing bass above 80Hz. (I'd be interested to compare large groups of cabs, and with V-Plating). Tom Danley would bow down and worship anyone who could get a flat 107dB efficiency (8 ohm half space) to 40Hz out of an 8 cubic foot cab!
Martin Audio Professional Loudspeaker Systems ? Unite Your Audience claims 105dB sensitivity with no SPL chart though I found that's possible in theory.
Corner load said cab and you're not far off horn territory. About 115dB sensitivity in a corner, same as John Inlow's version of the Lab Sub but smaller.
I did a rough comparison of two of the P-Audio design above (before down sizing) vs the dual 12 T60 both in corner.
The T60 was A: bigger, B: got lower (25Hz vs just below 30), C: Handled more power (50V vs 35V) D: Used more expensive drivers
The P-Audio was a bit more sensitive between 30 and 40Hz if I recall, but not much in it. I concluded horns only had an advantage if they were bigger.
As such, it seems a small horn cab like the 24" wide T24 has no advantage over a single 15/18 reflex by itself. Judging only by the provided charts it seems to be considerably LESS efficient than a 3015lf in a box of the same external dimensions with sensitivity drooping into the lower 90s instead of a flat 98-99. Considering it's advertised as having a 9dB sensitivity rating over a 1x18 by itself (100 watts outpower an 18 with 800). Though more efficient at reproducing bass above 80Hz. (I'd be interested to compare large groups of cabs, and with V-Plating). Tom Danley would bow down and worship anyone who could get a flat 107dB efficiency (8 ohm half space) to 40Hz out of an 8 cubic foot cab!
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The advantage to the t24 is driver cost. You can buy 3-4 bp102s to each kappalite 3015, tipping the output advantage ( for the dollar ) well into the t24 court.
Cheaper driver costs = more plans sold. Bfm wouldnt be as successful as a plan seller if all hi designs used $800 drivers. People are not even willing to put up the 200 for a 3015 in most cases over there on the forum.
I still stand by the fact that hornresp does not accuratly represet multiple vented cabs (or a vented cab in 1 pi/ .5 pi) because it displays a lowering in tuning (frequency of displacement minima moves to the left)
Cheaper driver costs = more plans sold. Bfm wouldnt be as successful as a plan seller if all hi designs used $800 drivers. People are not even willing to put up the 200 for a 3015 in most cases over there on the forum.
I still stand by the fact that hornresp does not accuratly represet multiple vented cabs (or a vented cab in 1 pi/ .5 pi) because it displays a lowering in tuning (frequency of displacement minima moves to the left)
FWIW, I just did a quick and dirty experiment with one of my small vented cabs and yes, there is a small but measurable downward shift when I "load" it with a corner. The upper impedance peak also noticeably decreased.
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hornresp would likely predict a shift of about 5hz in that example. (I'm assuming that lower impedance spike is around 45?)
I haven't modeled the enclosure in HornResp to see what it would predict.
I measured the enclosure in free air, and then mounted up close to where a wall met the floor, so it was more in 1PI rather than 0.5PI space.
As it wasn't perfect 1PI loading, I don't expect that the measured result would exactly match any HornResp prediction, but it certainly shows that there IS an effect on Fb when the loading on the system is changed.
Hi,
First: Agree with Brian's findings...
Couldn't resist: Don't blame HR,: Blame your ignorance in Applied Acoustics.
IMO it is stupid to do an Apple to Orange comparison when building a Speaker Box that differs in outline compared to the default of the HR Schematic Diagram.
b🙂
First: Agree with Brian's findings...
Couldn't resist: Don't blame HR,: Blame your ignorance in Applied Acoustics.
IMO it is stupid to do an Apple to Orange comparison when building a Speaker Box that differs in outline compared to the default of the HR Schematic Diagram.
b🙂
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Sine, the larger and more efficient the cab, the bigger the shift - thus you wouldn't notice much on a little computer or sony home theatre sub but in a 10 cubic foot 18 cab there would be quite a bit. It's probably caused by the extra air resistance loading the ports (or approaching the efficiency ceiling.)
In simulations of tapped horns it happens too, although the advantage seems to be squashing the displacement peaks, whereas with bass reflex they grow (as if you lowered the tuning). With front loaded horns I'm not sure.
The predicted helmholtz of my vented 3012lf cab goes from 40.66 Hz to just above 37Hz. Half space to corner. I'll have a look with my eye at the cone next time I get the chance. I always corner load anyway.
On account of the Tuba 24, 2 x Eminence BP102 = £120, 1 x P-Audio E18 600s = £110 to theoretically smoke it in output in this design. Higher sensitivity, higher voltage limit 40V vs 35V, less power compression with 600 watt thermal limit that never gets used, easier build, less wood so lighter, no access panels to cut etc. So might be worth it in USA but not here. Titans and V-Coupled T30s should be awesome but see no advantage to T24. T18/Autotuba, couple of cheap MCM 8"s in a wide one should make it as loud as my 3012lf VB, so definite advantage there for US users!
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Well just bought a 2nd hand P Audio E18 600s for £60! Says in good condition, hope he's not lying!! I guess I can try out this design in the real world and see if it's any good, certainly cheaper than shipping Kappalite drivers. A good designer must put his/her creation into the real world before they expect anyone else to trust the schematics. My only problem is filling my place with large boxes.
In response to sine143, this design is predicted to lower its tuning A LOT when corner loaded, especially 2 in a corner. It can be a blessing and a curse (if you favour high SPL and headroom) My tapped horn design in progress (For Faital Pro HP 1030/1060P or 3012lf or 6 MCM 55 2421) seems to be more resistant to the 'corner detuning' phenomenon, although it still does it slightly, it actually reduces displacement instead of increasing it in the BR designs. THs also draw more power when corner loaded.
There is a somewhat annoying fact that undersizing a reflex box and taking the inefficient roll off does make the driver be less vulnerable below the high pass. I do see the logic behind the somewhat undersized Simplexx 15 sub and similar in that it means less people will overextend the drivers.
I like to use the 'Chebychev' curve just because it gives you the most low bass possible and SPL within the displacement range, although it does require lower Q drivers, and a steeper highpass filter to avoid bumping the coils.
In response to sine143, this design is predicted to lower its tuning A LOT when corner loaded, especially 2 in a corner. It can be a blessing and a curse (if you favour high SPL and headroom) My tapped horn design in progress (For Faital Pro HP 1030/1060P or 3012lf or 6 MCM 55 2421) seems to be more resistant to the 'corner detuning' phenomenon, although it still does it slightly, it actually reduces displacement instead of increasing it in the BR designs. THs also draw more power when corner loaded.
There is a somewhat annoying fact that undersizing a reflex box and taking the inefficient roll off does make the driver be less vulnerable below the high pass. I do see the logic behind the somewhat undersized Simplexx 15 sub and similar in that it means less people will overextend the drivers.
I like to use the 'Chebychev' curve just because it gives you the most low bass possible and SPL within the displacement range, although it does require lower Q drivers, and a steeper highpass filter to avoid bumping the coils.
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You cant know if it will be worth the money or not but have a look at the sellers and the "zero feedback" ones, and warranty (how much POSTAGE AND PACKAGING cost to return an item).
He's agreed to refund me so it's not all bad. Ill just have to pay a tenner postage. I'd advise being careful though buying used woofers on ebay, it's easy enough to say they work well but some of them may have lost their backplate virginity. In the words of Howard Wolowitz, they 'Hit That Thang'.
A light push on the cone and a slight sound. Plugged in some low power bass and it sounded like a fart machine just moving. Looks like he upgraded to some Fane colossus 18XB judging by the box it came in. A brand new one is 110 quid anyway. Much cheaper than eminence.
A light push on the cone and a slight sound. Plugged in some low power bass and it sounded like a fart machine just moving. Looks like he upgraded to some Fane colossus 18XB judging by the box it came in. A brand new one is 110 quid anyway. Much cheaper than eminence.
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