54 replies to this topic

[Calman]

ok cheers. just out of curisosity how o you work out what amp you need ( power output ) because ive heard you just add up all of the rms things from each speaker and get an amp that is a bit over your total. is this true?

i did look for an online calculator but found nout.

[monkeybiz]

ok cheers. just out of curisosity how o you work out what amp you need ( power output ) because ive heard you just add up all of the rms things from each speaker and get an amp that is a bit over your total. is this true?

i did look for an online calculator but found nout.

do you want quality or quantity??

quality= soundstream, rockford fosgate, genesis ect to name a few

quantity= cheapo brands generally

if i was you...... looking at what you have on your wish list id go for a pair of JBL amps... GTO4000's cheap and look quite cool
mids and tweeters off one 4 channel amp and bridge the other for the subs.
and if i were going JBL amps go for JBL speakers as they are designed for thier amps

or go for bling with the west coast customs amps

oh and the RMS rating of the speakers should be at least 50% more than the RMS rating of the amp

Edited by monkeybiz, 30 September 2009 - 04:48 PM.

[Calman]

just googled it an the reviews came up good but its bloody ugly ! Haha.

Was i right in saying about the toting up the rms? Just that way i could go find a nice looking amp and i will know what sort of output i need.

Thanks

EDIT

Just edited your post swine jkes, so if i ad up all the rms and for arguements sake its 500 rms, would i be looking at a 750 + rms amp at the correct ohm?

Edited by C93, 30 September 2009 - 04:52 PM.

[monkeybiz]

just googled it an the reviews came up good but its bloody ugly ! Haha.

Was i right in saying about the toting up the rms? Just that way i could go find a nice looking amp and i will know what sort of output i need.

Thanks

EDIT

Just edited your post swine jkes, so if i ad up all the rms and for arguements sake its 500 rms, would i be looking at a 750 + rms amp at the correct ohm?

other way round dude, dont want to put to much power through them speakers

subs will be.... say 250w rms each so looking for a 200w per channel amp to powre them, your front speakers will be on another amp/channel so if they are 100w look at 75w per channel....

on the other side of the coin you are young and deaf from wearing an ipod since birth you will kill the speakers by driving the amp into distortion ie clipping which turns the sine wave into a square wave by "clipping" the upper and lower points thus producing pure dc and that will fry a speaker

tell me exacty what speakers you are going to get... not a would like list because it will change!
tell me the manufacturer of amp you will get and ill tell you the model

or tell me your budget and manufacturer you want and ill compose a list



20+ years ago i went to change my old amstrad tape deck in my car for a new tape deck, ended up spending £3k!!!! it happens. for a first system stick with a well known reliable company and kit your car out, thats why i said JBL, in the world of ice shiney and bright colours means crap, boaring and ugly generally means the money is spent where it counts

here is my amp


but look at the inside

[Calman]

Thanks for all the help monkeybiz!

I cant get an exsact list because its like you said a list atm! But after searching a few sites last nite i think i found what i would like. The list above by the way
Its a good brand
Look great in my opinion
Good reviews
All at a resonable price

-------------------------------------------------

3k! OMG lol went a little over our budget did we ?
Mind you the amount you seem to know i bet it was all money well spent!

Oh and by the way nice amp!

*Goes off amp hunting*

[Calman]

Two things that have popped up;

1) For the paired speakers (6x9's and the 5 1/4") The RMS power output - is that per speaker or them together.
2) The smallest speakers are running at 3.6 ohm but the 6x9's and the subs dont say. Shall i assume 2 or 4?

Thanks

[monkeybiz]

Thanks for all the help monkeybiz!

I cant get an exsact list because its like you said a list atm! But after searching a few sites last nite i think i found what i would like. The list above by the way
Its a good brand
Look great in my opinion
Good reviews
All at a resonable price

-------------------------------------------------

3k! OMG lol went a little over our budget did we ?
Mind you the amount you seem to know i bet it was all money well spent!

Oh and by the way nice amp!

*Goes off amp hunting*

stick to alpine amps for the alpine stuff, nice stuff........... still use a nearly 20 year old alpine head unit as i still cant get one the same quality.
treat each single speaker as one amp output....
sub=200w
front =100w
ect
then match that to the amps
2subs=1 2 channel amp
2 front speakers= another 2 channel amp
dont just add it all up as there all powrered from different channels/amps

and yes over budget but i didnt get it right till years and god knows how much money later

audiophile grade list
alpine 7909 (year produced approx 1991)
old soundstream reference or Phoenix gold ms 275/mps 2220/mps2240 (year produced approx 1993)
old focal 6" (year produced approx 1995)
PPi horn tweeters (year produced approx 1995)
diamond or jl audio dual voice coil sub, if the pg amp 2 dual 4ohm wired in series aprallel series to produce 1ohm in a isobaric bandpass box (in push pull mode) (year produced approx 1994)
nice parametric equaliser
and that is it

just need to find some more focal speakers and im back to where i was 15 years ago. my old focals died about 5 years ago

Edited by monkeybiz, 30 September 2009 - 07:14 PM.

[Calman]

Two things that have popped up;

1) For the paired speakers (6x9's and the 5 1/4") The RMS power output - is that per speaker or them together.
2) The smallest speakers are running at 3.6 ohm but the 6x9's and the subs dont say. Shall i assume 2 or 4?

Thanks

OK cheers ive narrowed down a few amps bu got stuck ^.

Thanks

[monkeybiz]

1) For the paired speakers (6x9's and the 5 1/4") The RMS power output - is that per speaker or them together.

per speaker, they dont get powered from the same channel. if you have front speakers that are 120w you want a 100w per channel amp just for those speakers
if the 6x9's (ditch them as they will do nothing and are a waste of money in your system due to the subs) are 190w you will want about a 150w per channel amp just for those speakers.
your subs are say 250w you will want a 200w per channel amp just for those speakers

thats 3 amps you need so far


2) The smallest speakers are running at 3.6 ohm but the 6x9's and the subs dont say. Shall i assume 2 or 4?

over the frequency range the ohms change fron 2-20 ohms the rating is normally the lowest they will go but may go up to 20ohms at 20khz but only 3,6 at 100htz

assume all your speakers are 4ohms each. end of story

[Calman]

OK cheers for clearing that up for me

BRB with a list *hopefuly*

[monkeybiz]

look at this for what a speaker does

[Calman]

Right thsi first, Clicky , was for both subs, - I know you said to treat each speaker seperatly but i think this may work?

Each sub = 500w so im looking for a 400 -> 450w amp. The one ^ up there ^ is 400w on each channel - so heres the bit i got confused with, could i run each sub off one channel and then this;



Headunit to power the two 5 1/4" up front. Only thing is its putting out 45wx4. Is there some sort of resistor i can put in the line or will it be ok as is?

Thanks.

PS I know this is now a 3 page thread now, just wanted to say i appreciate the help and all the questions and quite probably all the hair you've pulled out when im to thick to understand!

[monkeybiz]

Right thsi first, Clicky , was for both subs, - I know you said to treat each speaker seperatly but i think this may work?

Each sub = 500w so im looking for a 400 -> 450w amp. The one ^ up there ^ is 400w on each channel - so heres the bit i got confused with, could i run each sub off one channel and then this;



Headunit to power the two 5 1/4" up front. Only thing is its putting out 45wx4. Is there some sort of resistor i can put in the line or will it be ok as is?

Thanks.

PS I know this is now a 3 page thread now, just wanted to say i appreciate the help and all the questions and quite probably all the hair you've pulled out when im to thick to understand!

amp, good choice. looks good on paper
the head unit will really only be about 4x13w or there abouts.................

what you could do is...............

stick a pair of 6.4Mh coils on each sub, a pair of 200mf caps on the components and run the lot from the one amp
basically you will have a 3 way filter which will keep the ohmage like the graph above..... a very basic 3 way passive crossover

no worries about the questions we all had to start somewhere its good now to be able to pass it on to someone who listens

[monkeybiz]

oh and makes no difference on the amount of pages, its better that than hundreds of £ down the drain on an awfull ned sounding system

[pbrain]

Thanks for all the help monkeybiz!

I cant get an exsact list because its like you said a list atm! But after searching a few sites last nite i think i found what i would like. The list above by the way
Its a good brand
Look great in my opinion
Good reviews
All at a resonable price

-------------------------------------------------

3k! OMG lol went a little over our budget did we ?
Mind you the amount you seem to know i bet it was all money well spent!

Oh and by the way nice amp!

*Goes off amp hunting*

stick to alpine amps for the alpine stuff, nice stuff........... still use a nearly 20 year old alpine head unit as i still cant get one the same quality.
treat each single speaker as one amp output....
sub=200w
front =100w
ect
then match that to the amps
2subs=1 2 channel amp
2 front speakers= another 2 channel amp
dont just add it all up as there all powrered from different channels/amps

and yes over budget but i didnt get it right till years and god knows how much money later

audiophile grade list
alpine 7909 (year produced approx 1991)
old soundstream reference or Phoenix gold ms 275/mps 2220/mps2240 (year produced approx 1993)
old focal 6" (year produced approx 1995)
PPi horn tweeters (year produced approx 1995)
diamond or jl audio dual voice coil sub, if the pg amp 2 dual 4ohm wired in series aprallel series to produce 1ohm in a isobaric bandpass box (in push pull mode) (year produced approx 1994)
nice parametric equaliser
and that is it

just need to find some more focal speakers and im back to where i was 15 years ago. my old focals died about 5 years ago

If you like audiophile grade HUs see if you can get hold of an Alpine 7998 (aka fantom face) you'll find these quite cheap now that most people are wanting solid-state HUs, excellent audio features inc digital delay lines per channel, solid copper housing, external DC-DC converters...and a basic mono-colour display (no flashing xmas tree effects)