Sub with built in amp

[Blitz]

I just want a small sub and I've seen some subs with a built in amp. Are they good?

Also would I need two amps, one powering the sub and one for the speakers?

[aj_mckay]

I've heard the Vibe active subs are alright for the money - Vibe also make Fli active subs I believe and have also heard they're OK. You can prob pick one up off Ebay at a reasonable price. You'd need a separate amplifier for speakers though if you want them amplified...

[Alex]

get a sub and a 4 channel amp, run all speakers of "front" and bridge the sub of the "rear"

make sure one of the channels have a bass boost and built in corssovers for the sub, im sure most probably do

[Blitz]

Thanks

[cliffybabe]

off topic hos the cabby coming??

[Blitz]

get a sub and a 4 channel amp, run all speakers of "front" and bridge the sub of the "rear"

make sure one of the channels have a bass boost and built in corssovers for the sub, im sure most probably do

Do all 4 channel amps have the capability to do this?

[Alex]

get a sub and a 4 channel amp, run all speakers of "front" and bridge the sub of the "rear"

make sure one of the channels have a bass boost and built in corssovers for the sub, im sure most probably do

Do all 4 channel amps have the capability to do this?

i think so, but dont hold me against it

http://caraudiosecurity.com/shop/produc ... /1180.html

thats the amp ive got, i paid full price for it early last year

[mrLEE30]

the number of channels on an amp mean the number of channel outputs, each channel is normally for driving one speaker. and each channel has a specific output (normally made to look much higher then actual by quoteing max power output and at lower then normal impedance). the real figure you need is RMS (root mean square) power, this is a statistical method of measureing the mean or average power output of an amp (as the actual voltage and current output is constantly varying) so as you see from the link provided by alex it is a 400W four channel amp, but really 60W RMS per channel of output (still a powerful amp! and one that i can vouch for having one in the past, it stood up to our summer heat with no problems)

now it is possible to bridge two channels to make one channel, bridging means you run one stage (channel) of the amp from the output from the first stage which effectively doubles the power, thus 2 x 60W RMS channles bridged can drive one speaker at about double power (but the mathematics becomes complicated so its not really double but approximately double). so you could run two speakers off a channel each and one sub - thus a 3 channel amp. or if you wanted you could run two speakers each bridged on two channels, thus a two channel amp.

the other part of the equasion is how many inputs drive these channels, normally on a four channel amp you would have two inputs (the RCA leads coming from your head unit) with one input for two output channels, it is not normally possible to drive all four channels from one input, so you would need two inputs (which means you need two outputs from your head unit) most head units dont have more than one output so it becomes difficult to run a multiple channel amp properly.

have you considered not bothering with a sub for now? a good set of 6x9 or 7x10 fitted correctly in the rear parcel shelf and some good quality 5 1/2 in the front all driven from an amp as suggested by alex. this would sound very good. then once funds allow look at fitting a sub with a one channel amp??

if you tell me what you have in the car now i.e. what speakers and what head unit I can help you to devise a system that would sound good on a budget (and what is your budget?)

mrlee

[Blitz]

off topic hos the cabby coming??

Its the same. Starts every time now. Needs some paint in some areas. I'm just taking it slowly as I plan to sell it in the summer.

[Blitz]

the number of channels on an amp mean the number of channel outputs, each channel is normally for driving one speaker. and each channel has a specific output (normally made to look much higher then actual by quoteing max power output and at lower then normal impedance). the real figure you need is RMS (root mean square) power, this is a statistical method of measureing the mean or average power output of an amp (as the actual voltage and current output is constantly varying) so as you see from the link provided by alex it is a 400W four channel amp, but really 60W RMS per channel of output (still a powerful amp! and one that i can vouch for having one in the past, it stood up to our summer heat with no problems)

now it is possible to bridge two channels to make one channel, bridging means you run one stage (channel) of the amp from the output from the first stage which effectively doubles the power, thus 2 x 60W RMS channles bridged can drive one speaker at about double power (but the mathematics becomes complicated so its not really double but approximately double). so you could run two speakers off a channel each and one sub - thus a 3 channel amp. or if you wanted you could run two speakers each bridged on two channels, thus a two channel amp.

the other part of the equasion is how many inputs drive these channels, normally on a four channel amp you would have two inputs (the RCA leads coming from your head unit) with one input for two output channels, it is not normally possible to drive all four channels from one input, so you would need two inputs (which means you need two outputs from your head unit) most head units dont have more than one output so it becomes difficult to run a multiple channel amp properly.

have you considered not bothering with a sub for now? a good set of 6x9 or 7x10 fitted correctly in the rear parcel shelf and some good quality 5 1/2 in the front all driven from an amp as suggested by alex. this would sound very good. then once funds allow look at fitting a sub with a one channel amp??

if you tell me what you have in the car now i.e. what speakers and what head unit I can help you to devise a system that would sound good on a budget (and what is your budget?)

mrlee

I'm not too bothered about a sub that much as its the first time looking for audio for my car. I have a BMW Business RDS from a E36, not fitted yet. Crappy Pioneer co-axials 5 1/4 in the front. My budget is max £100.

[Blitz]

get a sub and a 4 channel amp, run all speakers of "front" and bridge the sub of the "rear"

make sure one of the channels have a bass boost and built in corssovers for the sub, im sure most probably do

Do all 4 channel amps have the capability to do this?

i think so, but dont hold me against it

http://caraudiosecurity.com/shop/produc ... /1180.html

thats the amp ive got, i paid full price for it early last year

Not as expensive as I thought.

[Alex]

you can get a sub pretty cheap too

a seperate sub and amp might be cheaper than an active sub

[mrLEE30]

if you have the BMW RDS radio then it is quite unlikely it will have one RCA lead let alone front rear and sub pre outs. if you can describe or take a pic of the rear of the unit (with any cables) then that would enable me to confirm.

in this case it is not so easy to run an amp, but all is not lost!! if you look at some of the lower end Sony Xplod amps they accept high level inputs, this mean you can wire your speaker wires directly into an amp, the 222 Xplod http://phoenix.craigslist.org/evl/ele/994831304.html for example.

the pros are these are normally cheaper amps and thus suit the budget, the cons is they will never sound as good as a proper RCA set up.

my advise is get something like the link above and use that to run a set of decent 6x9 in your rear parcel shelf. wire the stereo in with the front speakers running from the head unit, then the speaker wires for the rear speakers into the high level input of the amp and then to the 6x9's.

this way you have cenough cash now for an amp and some 6x9 and some change!! the system will sound quite good and get you a step closer to what you want. later if you get into ICE you can buy a head unit with front, rear and sub RCA outputs, a 4 channel amp and a sub plus enclosure. use the smaller Xplod to run the front speakers and the 4 channel to run the 6x9 and sub - this way you use what ever you have already bought but in a different way.

let me know if you want a quick diagram of what i mean in both cases.

mrlee

[Blitz]

I think Alex some RCA cable things.

[Alex]

http://cgi.ebay.co.uk/Boss-Audio-High-l ... 18Q2el1247

that’s what you would need for your Bmw radio

im having dirty thoughts of amping my old 1990 blaupunk tape player in the garage and building a mp3 fm transmitter in somewhere

now that would be stelth

[Blitz]

http://cgi.ebay.co.uk/Boss-Audio-High-l ... 18Q2el1247

that’s what you would need for your Bmw radio

im having dirty thoughts of amping my old 1990 blaupunk tape player in the garage and building a mp3 fm transmitter in somewhere

now that would be stelth

I'm going to use a cassette Mp3 thing. Plug any 3.5mm jack.