minimum RMS.... (LONG READ)

[NOCTURNAL]

OK so I'm not a complete Numpty, But havent even considered anything Ice related for something like 12 years LOL...
Things seem to have moved on rather.... and yet I find it hard to understand some of "how" it can have moved on....

Ok thats weird enough, only the really sad or ice geeks will still be reading now bear with me

My Dilemma... I have a brand new Amp, thats something like 10-12 years old...
It cost me a bomb at the time , and was considered the 'best' (in its day AT IT'S PRICE POINT £450) However by todays standards its puny in it's output... 6x50W RMS but thats true figures, and generally considered conservative.

Now when purchased this Denon DCA800 was rave reviewed ....
basically powering 2x50W front, 2x 50W rear, and 2 sub or 1x bridged 100W sub.

These days 50W dosent even register.....
Now It dosent become a bad amp overnight, and if it sounded good back then...presumably matched to 50w speakers.....
It should sound good Now... (still with me?)

Now a little bit of research has told me I need to match the speakers (probably particularly the sub) in RMS wattage amongst other things...

My budget isnt fixed, but is tight....
But looking for some well reviewed offerings on the bay, picked a few out for shortlist, only to find the sub for instance is rated @ 400RMS and sillyamounts peak(but we'll ignore that)

OK so 2 part question finally, why does everything need to be soo much bigger (power) now, when it all sounded good at for instance 50F/50R/100Sub back then?....
and
whats the minimum RMS power these new subs will still perform at?

for me personally it will be STRICTLY SQ NOT SPL!! so wont be 'cranked up waking the dead'


i.e. do I need to strictly match the 100W amp sub output with 100W rms rated subwoofer?
or can I still use a decent quality 400w rms rated sub or maybe a 250w?
when taking into account I wont be cranking it up all the time so unlikely to introduce distortion and clipping....
I dont want to end up with damaged speakers just because I was underpowering them however.


ok if youre still here I assume youre an Ice geek, cos even the sad ones will have given up by now

Same questions reference to the components...some I've seen rated at 100W rms will these simply underperform when powered with the 50W amp? or is damge a possability

one last question....

If the 100w rms components are not really an option due to underpowering, could I bridge the front rear channels for 100W left and right, and run the rear fill 5.25 components from the head unit ...


Ok if you read this far THANKS If you can help....

Cheers Nick (Tired cos I should have gone to bed at 07.00 so forgive the garbled nature of the post)

[Simon]

Right....

Your amp will be fine

Whatever speakers you get, so long as their PEAK output is GREATER or equal to the MAXIMUM output of your amp, you'll be safe (makes sense, huh).

The other important factor if frequency range. Ensure the speakers can cope with the frequency range outputted by the amp. You may need cross overs etc to prevent certain speakers recieving frequencies above/below their operating range.

To be honest, 50Watts RMS output is very impressive. You'll be more than pleased with the results so long as the components are matched accordingly. You're always better getting higher-rated speakers then your amp as you'll know you'll always be safe and the amp will drive the speakers without causing them to distort or anything.

The bit about the frequency range is important because if your amp is pushing out frequencies that the speakers can't deliver you'll get distorted or poor sound reproduction.

The other thing to bear in mind is that the lower frequencies (those of longer wavelength) require much more power to generate, this is why a sub woofer will be rated at silly high RMS because you simply need more power to drive it. Tweeters are at the opposite end of the scale and don't require anywhere near as much power to drive them.

Does that help in anyway?

[NOCTURNAL]

Kind of
Thats the sort of "common sense Logic", that I had assumed myself initially
Except from the research I've done your first line isn't quite true...
Subs in particular can be damged by 'under'powering, when the underpowered amp can't cope with the volume if pushed, and therfore distorts and clips...
eventually damaging the speaker....

That said I wont be pushing it particularly, I'm just after improving the current rather 'empty sound'...

It is a good quality amp as I said, So in the absence of any negative responses after a while I think I might 'take a chance' at 4x50W and if the fronts don't sing I'll change the rears to the head as I suggested above.

I finaly had a response back from Infinity today, only took a week and it's hardly definate in its response, but it is posative
(I guess they were hardly going to say 'no don't buy our products' though were they hehe)

Hi,

With care the system will work ok. Just don't push the sub level too
hard as either the amp or speaker will suffer.

Best regards

Harman Consumer UK
Technical Support

Thanks for reading that far anyway Simon


Keep the replies comming anyone would think y'all got bored and didn't read the whole post

[Ti Rich]

Originally Posted by NOCTURNAL

That said I wont be pushing it particularly, I'm just after improving the current rather 'empty sound'...

If done right not sure you need the sub at all - depending on the music you listen too.

I would go for a good set of components in all 4 doors powered by the AMP. The speakers will need custom MDF mounts for sure (as i have done). The MDF supports are ESSENTIAL as the OE speakers are mounted in "free space" using the door card as the baffle chamber - not ideal at all!!!

I think you may be able do without the sub at all and still get good sound.

My Comp's are driven directly off the head unit (although they do have a high sensitivity to be fair).

The biggest restriction to quality sound in the ZT is the OE speakers and the way they are mounted.

[Skud Kid]

How hard you have to drive the amp depends on the voltage being recieved from the head unit, i.e if your head unit can produce 6 volt pre out then the amp wont have to work as hard (sensitivity stays low so no clipping) hence you will be able to drive a more powerfull sub

As stated 100w bridged RMS is useally more than enough for a average sub

[NOCTURNAL]

thanks for the replies guys..

so you agree that my 100w rms capable amp should have no problems driving a sub rated @ 400w rms Skud?



Unfortunately Its the stock headunit so no chance of a 6 volt pre-out hehe...
However, as I intend using an loc with output adjustment I should be able to optimise the level for the amp at least
The input sensitivity is 100mV to 2V so I'm assuming thats the amp input (pre-out level)I need to match from the LOC.

Yeah I've already read your speaker posts Rich so have half an idea whats required for the speaker mounts and I have made some before, all be it many many years ago :P so once I finally take the plunge I'll have a good bash
I want to get everything bought and done in one hit so once I start theres no fannying about waiting for stuff.
I'll fit the rear doors first I think to see whats what .

Thanks again, Nick

[Ti Rich]

Nick

The heat unit should be the first to go mate!

The old saying garbage in - garbage out applies here for sure.

[Skud Kid]

I have to agree the thing i always advise to change is the head unit due to the processors in most new units being far better. You can get just as good a sound from a new head unit than you can with a amp if using original speakers.

If you adding a sub to get the best sound stage i would ditch the rears alltogether (unless you really need rear fill)

Amps help to increase the output of a speaker but mostly it adds a warmth and control to the sound but as you already have the amp i would:-

Change the head unit if you can if not use a loc and a line driver

Bridge the rear channels on the amp to run the sub (for sq set the frequency to about 80hz and below and play with the sensitivity till its right for you. Remember this may have to be higher than usual as we do have very well sealed boots. Turns the sub to face the ski hatch as this is the weekest point and sound can force through

Run a good set of components from the front channels of the amp and set this to 100hz and above, although within your frequecy range there is a gap from 80 - 100 i find this helps to eliminate sound crossover and keeps the sound clean and uncluttered

Get rid of the rear fill, its just more doors to rattle and you cant here them anyway over the upgraded stuff and adds another load to the head unit

[NOCTURNAL]

All Very well in Theory Guys but I sure as hell aint getting rid of the highline sat-nav/TV even though I'm sure its a week point.
both the costs, and asthetics involved rule it out I'm afraid

I allready have some MB Quart so I'll fit them in the rear doors as it will at least be there, and an improvement,and it will give me a bit of practice before making'n'fitting the fronts.

While I'm sure the Highline is a weekpoint I dont think its currently the problem with my 'empty sound'. I believe it to be the speakers being the main culprit. But as I have a perfectly good amp it seems sensible to try it.. with some new components.

Been out all morning so I've missed my trim removal tools arriving have to get to the post office Monday now

Thanks again for the advice guys, I'm afraid the HU just has to stay though

I'll see how the money lies next week as its mortgage time right now lol so might have to wait one more week :P

Nick

[NOCTURNAL]

ok, Secondary question,
assuming a bridged subwoofer output of at least 2 x50W so possibly a bit more...
would I be better off with a single 4 ohm single Voice coil SVQ or a dual 4 ohm voice coil DVQ, therefore presnting a 2ohm load?
The amp has a '2ohm' switch setting for when bridging any of the channels, does this theoretically free up more power, or is the '2ohm' switch just to help prevent clipping whenpresented with a 2 ohm load? as there is reference to this in the manual, however I think it is designed for when two speakers were used in mono mode, but I'm presuming, the two voice coils have the same effect ....

My guess is 2x4ohm voice coils in parralell would be better???

is this one for you Skud??

Cheers, Nick