05-16-2024, 11:57 AM | #683 | |
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BimmerTech Alpha One vs SWS-8xi
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I have installed the Alpha One speakers/amp and an additional amp just for the 8" under seat speakers. Has anyone seen a comparison of the Alpha One speakers to the SWS? The Alpha One's sound a lot better than OEM, especially after adding a dedicated amp I was wondering if the SWS will have better lower bass. It is difficult to find the Alpha One specs and I'm assuming they are just a rebrand of something else. Thanks for any feedback! 2016 F30 Dave |
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05-16-2024, 01:30 PM | #684 |
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There's the rub. If you don't have Thiele-Small parameters to software model different drivers and you don't have measured response charts to compare them then you have no way to compare them. You're correct about them being rebranded. This is one of the other sources: https://www.aliexpress.us/item/32568...%21rec%21US%21
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05-16-2024, 02:33 PM | #685 | |
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Anyone looking to upgrade the 8" under seat speakers should definitely get a dedicated amp first (I wish I had) as the speakers are almost silent without one so you will not even know how the OEM speakers sound until they are properly powered. |
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05-16-2024, 10:17 PM | #686 |
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One of the top ten rules in audio engineering is to always change one component at a time. Otherwise you have no way of knowing what any of the individual changes accomplished, if anything.
I have yet to come across any other underseat that has specs as good as the Earthquake, but without either a separate amp or an amp that has separate volume controls for the underseats versus the doors you won't get much, if any, benefit from them. Companies that don't publish full specs tend to be marketing companies selling sourced components. The don't show specs because they don't have them. |
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05-17-2024, 12:21 AM | #687 | |
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2 Ohm Xmax now 5.2mm from 22mm , QTS gone up a bit. 4 Ohm version has a QTS of 1.2 now as well. Power handling: 150W RMS / 300W MAX Impedance: 2-Ohm Sensitivity: 86.7 dB Recommended Sealed Internal Volumes Minimum: 0.2cu.ft. (5.66 Ltr) Maximum: 0.6cu.ft. (16.99 Ltr) Mounting depth: 2.04″ (52mm) Cut-out hole diameter: 8.11″ (206mm) Weight: 8 lbs (3.62 kgs) Recommended Sealed Internal Volume Minimum: 0.2cu.ft. (5.66Ltr) Maximum: 0.6cu.ft. (16.99Ltr) Assuming 3/4″ MDF is being used Parameters Revc: 1.800Ohm Fs: 42.796Hz Sd: 22.000msqM BL: 5.970TM Qms: 6.457 Qes: 1.037 Qts: 0.893 No: 0.00091% SPLo: 81.6dB Vas: 439.615mcuFt Cms: 181.127uM/N Krm: 612.228uOhm Erm: 0.976 Mms: 76.357g Mmd: 74.481mKg Kxm: 12.692mOhm Exm: 0.645 Xmax: 0.20 in (5.2mm) Xmech: 0.90 in (23mm) Xmax measured in one direction) https://earthquakesoundshop.com/prod...woofer-system/ Old specs Last edited by NealfromNZ; 05-17-2024 at 01:21 AM.. |
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05-17-2024, 10:12 AM | #688 |
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The model number is different, it's the i82. This is the SWS8X: https://earthquakesoundshop.com/prod...low-subwoofer/
And the SWS 8Xi: https://earthquakesoundshop.com/prod...hallow-woofer/ The Fs has gone up, though still lower than OEM. Between that and other changes it indicates they revised it, which isn't unusual. What matters is the result, and modeling it the response is almost the same as the original. As would be expected with higher Fs the new version is a bit more sensitive above 65Hz. They obviously realized that the lower Fs of the original couldn't be capitalized on with the tiny BMW enclosure. In short, they made it better. Also note the prices. The i82 is $260 per pair, making them $130 each. The 8Xi are $160 each. |
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NealfromNZ717.50 johnung4947.00 |
05-17-2024, 01:48 PM | #689 |
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Under seat sub wiring polarity?
Hey all! I'm hoping someone could share the wiring colors for the under-seat subs in the Bowers and Wilkins system. Just looking for which wire is + and which is - Thanks!
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05-17-2024, 07:23 PM | #690 | |
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Was the I version really 23mm Xmax would be my question. Has any owner on here seen how far the cone moves with grill off ? |
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05-17-2024, 10:38 PM | #691 |
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It doesn't matter all that much, as with the full 150w applied excursion doesn't exceed 11mm. To reach 23mm would require 750w, which would be long after the appearance of magic smoke.
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05-18-2024, 12:31 AM | #692 |
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So does that mean a 11mm spacer should be added between the mount plate and the grill?
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05-18-2024, 09:49 AM | #694 | |
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05-18-2024, 10:18 AM | #695 | |
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The spacer rings perform several functions. Obviously they lift up the Earthquake sub which is deeper than stock (see comparison photo) so that it fits perfectly in the stock mounting position inside the BMW underseat subwoofer cabinet. The stock subwoofer has a large rectangular plug that fits in the side. The Earthquake spacer ring uses this rectangular space for two spring connectors. To connect the stock BMW wires to the Earthquakes, simply clip off that stock BMW rectangular wiring connector, leaving 1-2 inches of wire in case you ever want to reinstall the stock subwoofers. Keep the connectors with the stock subs. Then simply strip the ends of the BMW speaker wire and insert them into the spring clips on the Earthquake spacer rings. The bottom side of the spacer ring has two wires coming out of the bottom of the spring posts. Simply attach them to the + and - on the Earthquake sub itself. See photos and my description will make sense. Removing a stock sub and installing Earthquake sun is easy. Remove the two bolts in front and two bolts behind a front seat that attach the seat rail to the car floor. Then tilt the seat back into the rear seat area. Do NOT disconnect any wires under the seat. See attached photos for some tips. Hope this helps someone! |
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anielsen71589.50 mazen22229.50 |
05-18-2024, 11:50 AM | #696 |
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There is also a fundamental design difference between between front and rear vented speaker motor options . This can make a difference with speaker grill clearance and if it requires spacers.
BMW and others do a front speaker motor, Later models of woofers from BMW such as Harman Kardon / BMW B&W / Morel / Audsion / Match and maybe Bavsound have vented motors to help with passive cooling of the woofers. Later BMW speaker grills have been modified to allow for front vented speaker motors , but do it in a way so dust from shoe debris or direct liquid can’t easily enter into the speaker vent but still allow cooling. ( cool eh ) Front vented speakers BMW front and many drop in options have a venteted metal plate above them to add as a stress bearer for the speaker grill and to protect the speaker and speaker grill from passengers legs. Excessive weight from passengers legs on the grill presses onto the speaker frame to stop the grill from caving in or cracking. Some aftermarket speaker with mid or rear facing speaker magnet structures ( earthquake/ speaker integrity / Integral audio ) don’t have the front speakers protect / weight bearing frames and take advantage of this for speaker cone travel so even with a modest spacer there is still enough cone clearance not to hit the grill. The heat from the speaker motor structure rather than venting into the cabin vents into the speaker enclosure. Rear vented speaker SWS also has additional motor cooling by using its alloy cone structure to aid cooling. ( cool eh ) SVSs by the look of it and having only 52mm of depth just clears the bottom side of the speaker enclosure so only only need a modesty thin spacer for speaker terminals and soft isolation ring ( isolation gasket important to reduce rattles ) . How close the speaker surround gets to the speaker grill when driven hard is interesting. 11 mm forward motion would be fine as Bill pointed out being an SWS at 150 watts. At 23mm of stated xmax this would be marginal clearance from when I took measurements of the enclosure face / grill height / seat rail relationship. Other options such as Integal audio which I’m assuming is a deeper speaker plus speaker mount include grill spacers to ensure clearance. Last edited by NealfromNZ; 05-18-2024 at 12:00 PM.. |
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05-18-2024, 09:49 PM | #697 |
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SWS 8xi blow Alpha One's away
So I installed the SWS under seat subs today and they blow the alpha ones out of the water. I used the provided ring spacer and left the dust cover off until I figure out if the cover also needs a spacer. With the carpet around trimmed it seems fine without the cover regardless. I am very happy with the how much lower and louder the SWS subs are!
Last edited by djv112; 05-18-2024 at 09:55 PM.. |
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05-18-2024, 11:54 PM | #699 |
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You could also try putting a bit of chalk on the top of the sws surround . Install the cover and feed it some lower frequency bass eg ( 35 hz) but not for too long ( don’t blow you new speakers ! ).
If the chalk shows any sign of being rubbed it’s hitting the cover. If not your good without spacing. Gently wipe chalk off with slightly damp micro towel. |
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05-22-2024, 04:08 PM | #700 |
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Update: I contacted SWS Earthquake regarding the specs issue. Not only did I get a reply, they pulled 2 and 4 ohm new versions of the 8x drivers and measured them. The xmax is 15mm for both. That's the mechanical coil length minus top plate measurement. Measured at 10% THD with Klippel it would be a few mm longer. Since they can't exceed 11mm at full power 15mm is plenty.
To do this is a level of customer service that's above and beyond. I'd expect it from one of the driver manufacturers whom I regularly work with on OEMs, but SWS doesn't know me from Adam, so either they did a quick google search of my name or they're just that good. I think they're just that good. |
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05-22-2024, 05:46 PM | #701 | |
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I’m not really understanding/following why the discussion on this thread about spacers. With the Earthquakes it’s really a no brainer. I just installed the Earthquake spacer kit, about $27 for a pair of Earthquake spacer rings with built-in wiring & spring connectors. (I posted photos on this thread) And the stock speaker faceplate installs right over the top of the sub. It really was one of the simplest mod installs that I’ve done on my BMW. |
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05-22-2024, 11:30 PM | #702 | |
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So they need to update the spec by the sounds of it . 5 mm Xmax and 23 mm xmech doesn’t line up with the above. But better than advertised . Was the QTS figures the same ? One was looking more suited to IB than semi - sealed. Great customer service BTW |
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05-23-2024, 08:11 AM | #703 |
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SWS-8Xi 2-Ohm Parameters
Revc (Ohm): 2.0 Fo (Hz): 39.8 Sd (cm): 283 Levc (uH): 1 Qms: 4.28 Qes: 1.01 Qts: 0.82 SPLo (dB): 84.1 Vas (cuFt): 0.88 Cms (uM/N): 233.39 Mms (g): 68.37 Xmax (Mechanical): 0.59 in (15 mm) - measured in one direction SWS-8X 4-Ohm Parameters Revc (Ohm): 3.6 Fo (Hz): 37.6 Sd (cm): 283 Levc (uH): 0.74 Qms: 5.47 Qes: 1.01 Qts: 0.85 SPLo (dB): 83.3 Vas (cuFt): 0.93 Cms (uM/N): 232.4 Mms (g): 76.76 Xmax (Mechanical): 0.59 in. (15 mm) - measured in one direction |
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NealfromNZ717.50 |
05-26-2024, 02:12 PM | #704 | |
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