How do you "measure" a speaker?
Discussion
Anxious not to sound stupid, but can I safely assume that a, say 13cm, speaker is 13cm across (diameter) when measured from the front, with the grill on? If not, then how do I measure it?
Also, with speakers, I understand the MHz thing with sound range, therefore if the lower number in the range is lower still - does that mean it handles bass better?
Also, what's a crossover - and will I need one if I want to fit tweeters to my new front door speakers?
Thanks folks!
Also, with speakers, I understand the MHz thing with sound range, therefore if the lower number in the range is lower still - does that mean it handles bass better?
Also, what's a crossover - and will I need one if I want to fit tweeters to my new front door speakers?
Thanks folks!
http://hyperphysics.phy-astr.gsu.edu/hbase/audio/spkcon.html#c1
has a nice set of data about speakers & basic characteristics including tweeter/woofer stuff.
Generally the human ear hears from around 30Hz - 15KHz and the audio characteristics of different speakers are setup accordingly. A crossover is used to feed the appropriate frequencies to the speakers that are best setup to handle them.
All speakers perform by moving air; with lower frequencies (below c.200Hz) the speaker itself often requires an 'enlosure' (i.e. box) to provide assitance with it's air movement (oversimplification) - hence subwoofers often come in tubes/boxes or the requirement to be mounted in a particular manner, Mid-range and tweeters are often less fussy in their installation requirements.
usually, in-car speaker measurements are referencing the diameter of the driver (including the rubber suspension mounting), the hole to accept the speaker is often slightly smaller, but can vary from manufacturer to manufacturer.
As with most stuff, you definitely get what you pay for with respect to in-car hi-fi. Take advice from a recommended source before parting with any cash - prefereably one who has TVR install experience.
has a nice set of data about speakers & basic characteristics including tweeter/woofer stuff.
Generally the human ear hears from around 30Hz - 15KHz and the audio characteristics of different speakers are setup accordingly. A crossover is used to feed the appropriate frequencies to the speakers that are best setup to handle them.
All speakers perform by moving air; with lower frequencies (below c.200Hz) the speaker itself often requires an 'enlosure' (i.e. box) to provide assitance with it's air movement (oversimplification) - hence subwoofers often come in tubes/boxes or the requirement to be mounted in a particular manner, Mid-range and tweeters are often less fussy in their installation requirements.
usually, in-car speaker measurements are referencing the diameter of the driver (including the rubber suspension mounting), the hole to accept the speaker is often slightly smaller, but can vary from manufacturer to manufacturer.
As with most stuff, you definitely get what you pay for with respect to in-car hi-fi. Take advice from a recommended source before parting with any cash - prefereably one who has TVR install experience.
Hi,
Not being pedantic but just to clear things up, an enclosure improves the sound quality of the speaker by removing the 'rear radiance' of the speaker.
When a speaker cone moves forward it moves the air (obviously) and produces a sound. But when it moves backwards (partly due to the current in the voice coil and partly due to the rubber surround on the cone) it also moves air, which sadly is out of phase with the original sound produced by the forward movement. So to get rid of this unwanted sound produced by the backward movement you put the speaker in a box. A little oversimplified but that is the main reason.
Bear in mind that you won't get fantastic quality sound in a cerbera, especially if it has a sports exhaust
Rob.
Not being pedantic but just to clear things up, an enclosure improves the sound quality of the speaker by removing the 'rear radiance' of the speaker.
When a speaker cone moves forward it moves the air (obviously) and produces a sound. But when it moves backwards (partly due to the current in the voice coil and partly due to the rubber surround on the cone) it also moves air, which sadly is out of phase with the original sound produced by the forward movement. So to get rid of this unwanted sound produced by the backward movement you put the speaker in a box. A little oversimplified but that is the main reason.
Bear in mind that you won't get fantastic quality sound in a cerbera, especially if it has a sports exhaust
Rob.
I've found these Kenwood KFC-P503 for £75 all in, inclusive of delivery. They're from Car Audio Direct and are 13cm diameter. Anyone know if they're right or not?
It seems from a car stereo page I visited that the figure quoted (eg. 13cm) is from edge to edge of the speaker, including the metal surround (excluding any spurs which may stick out to accommodate mounting screws) ... and the hole diameter can be 3-4cm smaller sometimes, but is dependent on the speaker design itself.
Ian, I was going to go for coaxial, with a separate tweeter, but that means having to have a crossover (a box about the size of a packet of fags) which I'd be surprised at if I could get that in the door too without interfering with existing mechanicals. Have seen some nice speakers, as mentioned earlier, with tweeter kind'a mounted "in front" of the main speaker, but price alone suggests to me there's a price to pay re: quality, etc. Thing is, at the end of the day, I only really listen to it when I'm doing "boring" driving (ie. motorway or in traffic) - all else i'm happy with window down and listening to engine. The speakers in the back seem so small, and compactly tight in their space, that I'll do a straightforward swap for same brand as fronts but smaller of course. I'm anxious to avoid having to go subwoofer, amp, route, etc.
Cinman- I think you will have space for the crossover.. I had my door skin off last weekend..
I think the speaker will probably sound ok once the fibre glass is removed from behind it and I have a sneaking suspicion that you could spend as much as you like on the best speaker in the world and it would still sound pants because there is no air movement behind it.. just a theory.. I intend to hack mine out ASAP to test. I'm only in Surbiton/Tolworth if you want to compare notes?
I think the speaker will probably sound ok once the fibre glass is removed from behind it and I have a sneaking suspicion that you could spend as much as you like on the best speaker in the world and it would still sound pants because there is no air movement behind it.. just a theory.. I intend to hack mine out ASAP to test. I'm only in Surbiton/Tolworth if you want to compare notes?
That's close to me - I'm in Epsom, just the other side of Tolworth flyover/A3? I'm off to see Andy at APM on Saturday morning to exchange some HT leads and get them fitted along with new plugs (only 1hrs job I reckon) if you wanna meet up afterwards, unless of course you fancy a run down there as well (quite a nice drive down that way, all A3 to Liphook really).
Cinman - would've had a run but I've been booked to run a mate up to norwich to collect a fiat coupe/220BHP turbo thingy on saturday he's just aquired! Andy does mine too top man.. But later that day or another day we should meet up I live really close to the tower and red lion road.. if you mail me at Ian.firmstone@orange.co.uk I'll send you my number.. so many jobs so little time...bet U know the feeling!
Rob - exactly what I was trying to say - but you said it better - cheers!
In terms of in-car sounds; there are improvements that can be made by replacing speakers, but you really want to look at the signal being fed to the speaker too. A typical 4x50 Watt head-unit is struggling if its powering all four speakers at any apreciable volume - (as I've said before on this site, the power claims made by head-unit manufacturers are even more overstated than TVR BHP figures). If you are going to invest in better speakers (MB Quart and Infinity are 2 brands I always recommend) - bear in mind that they often place higher demands on the source that is powering them. For good in-car sounds you are always going to have to couple the speakers to a separate amplifier to notice any real benefit. You don't have to go down some max-power route, a good set of speakers (either component or integrated) and a modest amplifier (2x100w rms will suffice) need not set you back more than 250-300 quid...
In terms of in-car sounds; there are improvements that can be made by replacing speakers, but you really want to look at the signal being fed to the speaker too. A typical 4x50 Watt head-unit is struggling if its powering all four speakers at any apreciable volume - (as I've said before on this site, the power claims made by head-unit manufacturers are even more overstated than TVR BHP figures). If you are going to invest in better speakers (MB Quart and Infinity are 2 brands I always recommend) - bear in mind that they often place higher demands on the source that is powering them. For good in-car sounds you are always going to have to couple the speakers to a separate amplifier to notice any real benefit. You don't have to go down some max-power route, a good set of speakers (either component or integrated) and a modest amplifier (2x100w rms will suffice) need not set you back more than 250-300 quid...
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