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Car Audio, SYNC, MyFord Touch & Electronics The Forum for the Ford Focus audiophiles. The place to chat about automobile sound systems, security systems, or show off your I.C.E.!
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#11 | ||||
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Focus Fanatic
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The rated wattage is a function of many different areas of the driver. The coil, magnet, spider etc. High wattage drivers are made (more or less) for use without an enclosure (as in they will not destroy themselves). There very forgiving in that area, but they loose in efficiency. BTW: Old trick. If you remove that foam pad and (carefully) work some batting to fill up the enclosure, you will increase the internal audio volume by 1.2%. Do NOT let the batting come in contact with the spider or cone. When you tested the woofer, did you still have the crossover in place? If so, test just the woofer (no crossover). the lack of a lower resonance ('Q'), well, it's a tad hard for me to believe.
P.S. What are you using for a signal generator? Is it pure sign or quasi?
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Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance. Last of the Hatches #28 |
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#12 | ||||
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Focus Fanatic
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Quote:
I tested the speaker just like i did the other day but with the grills removed so they didnt block any sound. I can try the speaker without the crossover but im sure it would blow the tweeter without it hooked to the tweeter and im not about to do that. The signal is generated by the REW program. It will to a sub type signal or a speaker type. You can set it to sweep threw what ever range of frequencies you want. say 0-20,000 or i have mine set to 40-20,000 you can also set it at any level you want. Im using the default 75db This is one thing that the program doesnt do, or it can if you want to take the time is how the speaker can change at louder levels. One speaker may have a nice curve at 75db but not at say 80-85 i probobly listen to mine between 75-85db ide guess |
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#13 | ||||
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Focus Fanatic
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If you look at the other bass drivers, you will note that they all exhibit a hump in the response curve around the 60hz area. That is the freq of there natural resonance. All drivers have a natural resonance. When you don't see this, it is evidence that a bandpass filter is in play. Generally when tuning a box, your emphasis is on avoiding any reinforcement at the Q as it will result in 'unnatural' volumes. Or, as many do for car installs, you find a bass driver with a high 'Q' (~ 100hz) as this can be used to produce really loud bass without having to push the driver/amp hard (also sounds like sh-t but most value volume over quality anymore).
Batting is like loose insulation, but without the glass fibers. You can get it at any fabric store. Do not pack it tight. Just a nice loose fill. As I said, keep it away from the spider wind and the cone. If mounting the driver vertically, you can glue some light foam on the driver as a guard. Add > Note: This can affect the driver Q. Handy tip when tuning. Quote:
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Add > Note: you find the initial Q of a driver in free air if that spec is not included with the driver or unknown. Geez! i have not thought about this stuff in ages, and it's prob getting more complex than you want or need.
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Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance. Last of the Hatches #28 |
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#14 | ||||
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Focus Fanatic
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I didnt remove the crossover i just tested it like it came from the factory. I dont really think it will be much better though its in a factory sealed enclosure so i didnt even need to really mount it into a box.
The box i used is from a 7" klipsch woofer. Its 10X11X9.5 made from 1/2" mdf with a 2.25 X10" port. My calculation tool says its .44 cuft with a tunning of 50hz that seems pretty close to ideal demensions for this size of speaker dont you? The woofer this box was designed for is a 7" ROUND driver but a 6x8 oval looks very simmilar in size IMO its close enough. The white stuff in the back of the componet enclosure is some sort of batting, its not class but its somthing simmilar. |
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#15 | ||||
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Focus Fanatic
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Batting or Fiber Fill. The stuff they use in stuffed animals for kids, quilting etc. It's use is based on the theory of the "infinite baffle" as I recall. Per your pic, What there trying to damp is a standing wave. Your text box is fine. But again, just trivia if you really want to get into this. There are established standards for testing drivers. Now this is from memory, but there close. Standard test box is 1 cubic foot 'infinite baffle' (regardless if the woofer is made for a port) . DB meter or mic is placed 3 ft from front of driver. Box with driver is 3 ft from ground. Techinically, all this is supposed to happen in a anechoic chamber, but real world, any space that has carpeting, lots of soft furniture (or people) works pretty well for the average quality of test equipment. I cannot recall what the standard drive level (in DB) was, but I think 75 is right on or very close. As I said, if you have an driver that has an integrated tweeter, or is mounted to an enclosure and you cannot remove it, then you work with what you got. I would only 'mess' with it if something was obviously wrong, broken etc (or your just intensely curious). This is especially true for car speakers. OK, so where are we going with all this? Only in that I think you have a real interest in it, with proper tuning, you can make damn near any speaker sound good to great (within there loudness specs of course). I am talking about nuance where you can tell the lead guitar is using a tube amp (and the plate is overdriven), or a violin actually sounds good (note: I hate "whiny" violins). It's called 'detail', and admittedly it's my number one beef with most car (and many home) audio systems (although the space is very challenging/intimidating to design in. Hence why I throw up my hands and walk away anymore). I have gone to a few car audio contests, and I got to tell you, most times my initial thought is a lament of how much money the person just wasted on that system. Wife and I came up with a word that for these systems. "Flobberbot", which is an attempt to describe the sound.
__________________
Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance. Last of the Hatches #28 |
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#16 | ||||
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Focus Fanatic
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I just used the box to test all the drivers so that they were all in an enclosure that was the same for all of them. The box that im using has poly fill in it.
you said 1 cuft for a 6X8? that seems a little over sized for such a small driver. I didnt do these test at 3 feet i did them all at 1 foot. Ive dont the test at different distances before though, the high end is usualy lower is all that really changes. Other then that the plots will still be pretty much the same overall. What i mean is the cerwin vega will still have the most high end, the alpine will still have the most bass it will just change the curves a little on them all. Ive messed with mic placement, distance, using a wall or corner to increase bass i found for testing the general sound of a speaker 1-3 feet is the best. The plots pretty just confirm what i thought i heard. What i heard was the stock speakers didnt sound bad and compareed to other 6x8 speakers they hold their own pretty well. |
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#17 | ||||
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Focus Fanatic
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1 cuft was the standard (don't think it would have changed but maybe so?). The point of the sealed box is to provide that infinite baffle for testing only. all the formulas I ever used assumed this volume. 3ft as I recall was the distance established by some audio institute. For testing, you place the driver in the standard box, 3ft up on some sort of table or what have you, away from any walls or surfaces that will artificially reinforce the bass. Middle of a typical living room generally works best (curtains, large stuffed furniture, carpet etc. you get the idea!). You place the mic 3 ft from the driver center (because that is the established standard). If you place the driver near a wall or in a corner, your not measuring the driver alone and it gives you false results. Basically, if your testing, you ignore what sounds good to your ears and test to the standard(s) to give a uniform and honest comparative result. Do you have a book? Radio shack used to sell a real gem for about 10 bucks. It would get you there for all typical configurations (note BOSE multi-chamber, but def your typical stereo store fodder). I really recommend it as it contains a wealth of data and won't set you back serious dollars for the pro stuff.
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Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance. Last of the Hatches #28 |
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#18 | ||||
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Focus Fanatic
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1cuft is what my 10" subthump box is i think thats a bit big for these drivers. Maybe you are right since these are so called "free air" drivers. I myself dont put much into that though. I feel a speaker needs to be in a good wood box to really sound its best.
What sucks is when you go to a car audio store to demo speakers look at the enclosure they are in. They arnt in a metal/plastic door panel they are in nice thick MDF enclosures then when you install them they sound so different. worse Here is another test i ran with the stock OEM driver. at 1ft, then at 3ft then i put the driver in a different .44cuft sealed box and ran another test at 1ft (GREEN)
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#19 | ||||
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Focus Fanatic
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your right! I did some review. As long as you know the internal volume of your test box (vb) then your good. Sorry, I guess it has been longer than I thought.
Here is an excellent link you should explore, and I guess I better drag my books out before I stick my foot in my mouth again! http://sound.westhost.com/tsp.htm
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Steeda SRI w/CAI intake. Trubendz SS 2.5" . FR Susp/Struts. Tune by Tom (FocusPower). Rota Grids. SAP rear spoiler. Custom front air dam, rocker panel bits and Rear valance. Last of the Hatches #28 |
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#20 | ||||
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Focus Fanatic
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Quote:
To me im not as concerned with bass or treble i want a good midrange sounding speaker. You can usualy dial in or out a little more bass with the sub and you usualy have treble controls to brighten up the sound. I want more middle, a nice warm middle is what im looking for most in these panel speakers. |
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