Front speakers installed

[tshirt2k]

Just thought id show people how you can install mids without hacking the original grill up.

The Rivetted in speaker was drilled out and removed. This left some mounting holes. I fitted some U' type nuts (size 10 - 12 Screws) to the door. Can get these from halfrauds.

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After doing this i had to make the speaker baffle. For my speakers i used 18mm mdf for the speaker baffle the joined to a 15 mm mdf base. This all depends on the depth of the speaker. so measure carefully with the window wound down.

I had to offset the 18mm baffle( to the left on this side) so that the original speaker grill could be fitted in place. Otherwise it would touch the door pocket on the inside. Keep refitting the door pocket and check that its goin to clear before joining pieces together.

Dynamat extreme was put around the mounting location to prevent any vibration. i used two layers 'cos the U' nuts didn't allow the ring to fit flush to the door.(note :- I will be dynamatting the whole door at a later date)

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This shows the speaker baffle fitted to the door. Not how the mounting screws have cutouts in top baffle for clearance. and is about 8mm to the left. You should keep trial fitting the speaker to make sure it fits flush and doesn't stop window from goin all the way down.

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Speaker in postion.

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The grill will fit into position with the speaker in place

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[Tigz™]

style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" /> Im well impressed.

I have never heard of spring clips before.

The speaker ring looks fantastic, how do you get the shapes in the baffle?

How do the speakers sound now you have finally fitted them :wink: What amp are you powering them with?

[paulbin]

look like infinity speakers style="vertical-align:middle" emoid=":P" border="0" alt="tongue.gif" />

[nfbr]

nice !

[mattie]

looks like a good job ye done there

[tshirt2k]

style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" /> Im well impressed.

I have never heard of spring clips before.

The speaker ring looks fantastic, how do you get the shapes in the baffle?

How do the speakers sound now you have finally fitted them :wink: What amp are you powering them with?

I made a mistake, they are called "u nuts". They are usually what door panels etc are held on with but bigger.

The baffle was cut out using a router, and the inner and outer edges were rounded off using a rounding off bit. The recesses for the screws were cut out using a jigsaw with a thin blade to get tight shapes.

They are infinity's 65.5 cs im powering them with this

They sound very "clean" at the minute and i haven't adjusted gains and crossovers yet. style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" />

[Tigz™]

Ah yes I remember now.

You dont want to start knocking those rings up for a few beers then? :wink:

Really really wanna have a listen to your set up.

[tshirt2k]

I could possibly do some . all depends on speaker dimensions. When its set up i'll have to come to a meet somewhere.

All i need to know is what the crossovers on the amp should be set at. at the mo' the fronts are on hi pass above 80hz and the sub is low pass at around 100hz. how is yours set??

[Tigz™]

Subs passed at 80hz and the fronts are 100hz.

The RF mids Im useing atm are only 5.25" though so they cant really handle lower than that, even with 160w.

Theres a good guide to crossover set up here

[Snoopy]

Subs passed at 80hz and the fronts are 100hz.

Doesn't that leave a big hole in the response range?

[Tigz™]

No because the cut off points dont really cut off.

So the sub will still be playing 100hz as the mids will still be playing 80hz.

The the filters dont cut off all frequencies below a certan point, hang on, theres a thread somewhere...

[Tigz™]

A crossover consists of two or more filters designed to split the desired frequency range into parts. Each part then being assigned a dedicated drive unit (speaker). A `2-way` crossover has two filters: a high pass and a low pass, and is usually used to integrate a `mid-bass` and a tweeter.

Each filter then has several characteristics, one of which is it's slope (or `roll-off`), measured in decibels per octave (dB/oct). An octave being a factor of 2 of the original frequency. Thus 1kHz has octaves at 500Hz and 2kHz.

The rate of `roll-off` is always a factor of 6 (for ease of circuit design and calculation). The most popular types being 6dB/oct, 12dB/oct, and 24dB/oct. Further to the numerical rate of `roll-off`, filters are often asigned an 'order' number. Order numbers are again a factor of 6, thus a 1st order filter equates to 6dB/oct (1*6), 2nd order 12dB/oct (2*6), and 4th order 24dB/oct (4*6).

The other important filter characteristic is the filter point (crossover point where necessary). The filter point is that chosen at the design stage and equates to the '`half-power` point', or the frequency where output is -3dB (-3dB equating to a 50% reduction in power). *** This assumes the filter design uses -3dB, some designs are -6dB at the filter point ***.

For example: a 1kHz high pass filter. In it's most basic sense everything above 1kHz passes, everything below is discarded. That's not particularly accurate. The frequencies below 1kHz are not discraded, rather they are attenuated according to the rate of `roll-off` of the filter. Assuming 6dB/oct: The output from the filter is -3dB at 1kHz, an octave later (500Hz) the output is -9dB (ie the output is already -3dB, and the filter reduces that by a further -6dB). Another octave lower (250Hz) and the output will be -15dB. If the filter were 2nd order, 12dB/oct, the output would be -15dB within the space of an octave, ie at 500Hz. -15dB equates to over 95% reduction in power.

This should indicate the importance of high order filters, especially within high power systems, and especially with tweeters. With a 6dB/oct filter, low `mid-bass` frequencies will still be entering the tweeter. And even though the output is considerably reduced, if enough power is available, the percentage reduction may not be enough to stop tweeter damage.

Just for reference:

-3dB = 50% reduction, or a factor of 2

-6dB = 75% reduction, or a factor of 4

-12dB = 93.75% reduction, or a factor 16

-18dB = 98.4375% reduction, or a factor 64

-24dB = 99.609375% reduction, or a factor 256

NB: the factors work in a positive sense too, so that adding 3dB gain doubles the input. Whilst adding 18dB is 64 * the input, and the reason you have to be careful with 'boost' type controls!.

[Snoopy]

Understood, but I thought that would give you a response curve like this:

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But I might be wrong. I had mine set so the sub cutoff was at 150hz and the speaker cutoff at 100hz - was that wrong?

[Tigz™]

No your not wrong bud, but thats lots of things that can make a diffrence to the responce curve.

Diffrences in the car resident frequency (useal mad memory applies incase got the word wrong) can alter this, as can diffrences in peoples ears.

Even things like sitting in the passenger seat instead of drivers seat can alter how things sound.

I alter the frequencies untill I think the music should sound, I dont like a clash when you can hear both the sub and the mids playing together, always sounds deleyed.

Untill I sold the components (Im only useing one sub and one mid driver at the moment) I used to phase my mids, to stop it even further.

I dont think there's a right and wrong way of doing things.

Back to subject though.

I remember reading a post saying that, if you run your sub to 50hz and your mids to 100hz the extra power you can give the mids and sub, make a better sound than free ranging.

I'll try and find the post.

[Tigz™]

When people are designing and tuning an audio system in a car, they too often forget the effect that the CAR'S INTERIOR will play into the equation. I can't tell you how many cars I have been asked to help tune with subs crossed over at 50 Hz, and the midbass bandpassed at 50 Hz. If our cars were anechoic or at best, `semi-anechoic` chambers, or of near infinite size, this would be just fine. But they're not. They're very small spaces, have reflective surfaces everywhere, and have their own tuning function.

Running subs 50Hz lowpass and midbass from 100Hz or so highpass.

Why will this work? It will work because the car's transfer function will probably make it work.  

Take a 12" subwoofer for example. Put it in the trunk so that it is exciting the trunk's air space. Cross it over at 50 Hz at 36 dB/octave. Now, put it on an RTA. What are the chances that the difference between 50 Hz and 100 Hz will be 36 dB? (i.e. 50 Hz at 0 dB and 100 Hz at -36 dB). Highly unlikely, if not completely impossible inside the car. On the contrary, you'll find that the difference between 50 and 100 Hz will be more likely around 8 or 10 dB, maximum, and probably more like 6 or 7 dB.  

Same thing for midbass drivers. If you cross over a midbass driver in the kick panels at 200 Hz at 36 dB/octave, what are the chances that at 100 Hz, the output will be at -36 dB. Not hardly likely. Once again, you'll find that you'll have a `4-6` dB, maximum, drop in amplitude from 6 1/2" midbass drivers in the kick panels.

Many don't understand this concept. Crossovers don't mean a freakin' thing until you have the speakers in the car.

I haven't used band to band crossovers in my car since 1996. There has always been at least some "notching" of the filter.

If you put a sub in the trunk at 50 Hz, and then bring some good 6.5" midbasses in at 80 or 100 Hz, your jaw is going to drop when you hear how much midbass you have.

Get the speakers in the car, and then use the P9 to dial it in. I'll bet my next paycheck you won't need to cross the midbass over at the same frequency as the subs. If you do, there's something wrong!  

Scott

[Snoopy]

Interesting.

Ahh well, my new car manages to have a frequency response somewhat lower than Alexander Graham Bell's first prototype telephone, so I don't have to worry too much until I get some cash to sort it out style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" />

[Tigz™]

Dude I saw a system in a Smart roadster (spelling?)

from what Ive seen of pics of the interior (never seen one in real life) there looks more sq cubes than there was in the Smart.

I think if you go for something like we've descussed in the past, it'll be great in such a contained space.

Love going camping, as the system is so powerful when the rear end of the car has no airspace. style="vertical-align:middle" emoid=":D" border="0" alt="biggrin.gif" />