Focal speakers / amp question

[Big G]

Still mulling over speakers and Focal Polyglass 130V2 look the business with smashing build quality and excellent sound reproduction (if pricey at £185).

However, when looking about the web there seems to be a huge obsession that they MUST be amped for them to be any good. Question is, why?

After looking at the sensitivity for the speakers (91 db), I worked out that:

91db - 1w
94db - 2w
97db - 4w
100db - 8w
103db - 16w
106db - 32w
109db - 64w (beyond the RMS rating for the speaker and beyond the peak power of my headunit, so thats a no go)

So theyre going to be pretty much loud enough off the standard headunit (50W peak i believe?) without any additional amping involved.

So why the big insitance on another amp? Would love it if someone could explain it properly to me!

 

[Bryan]

ask over http://www.diyaudio.comhere and they will tell you the exact reason why

everyone else just believes that more power = better sound, there is much more of an art to it than that

 

[Big G]

Call me cynical, but I think youre right - there is a certain element of "more watts makes it better" on car audio forums. Some of the best sounding/expensive hifi valve amps are 40w RMS per channel (although require very sensitive/efficient speakers)

Perhaps an external amp is better quality and thats what people are "hearing" when using an external amp. I just find it hard to stomach that the amps on my brand new Alpine headunit arent up to the job for the inside of a Clio.

If anyone has a before/after experience with amping fronts, id like to hear it.

 

[Bryan]

quite simple really, if you think the internal amp is good enough to power them, do so, then get an amp and see if you can hear any difference

i can guarantee you that you will notice a marked improvement in clarity, the internal amplifier is only there to provide a small power source for the speakers, once you start to look at bigger power than 3wRMS (OE speakers) you are pushing the boudaries of the head units I/Amp

all signals are best listened to low, the more strain you put on the amp, the worse the clarity will be

yes it will power the speakers, but no, it wont sound anywhere near as good as it would power by and external amplifier amplifier

 

[Big G]

Hmmm, i think id need to compare them side by side (so to speak) then.

I had a demo of Genesis 13cm components (the non-audiophile ones) running off a headunit and they were plenty loud with great clarity for me. I just wondered how much weight there was to "external amp is a must".

 

[Jonesy]

Ive just amped my rear speakers gonna do fronts 2moro, but i have noticed quite a big difference, much better sound quality and goes much louder without distortion.

 

[Big G]

But if its distorting, then either the amp is clipping or the speakers are being overdriven?

As for louder, the Focal units will (remember this is the interior of a clio from just one of the speakers) produce 106 db at 35w.

For reference, 100db is (in terms of loudness):

"Jet takeoff (305 M), Outboard motor, power lawn mower, motorcycle, farm tractor, jackhammer, garbage truck".

Im not going to want to go that loud, so I dont see why (for example) 8w from a standard headunit wont sound as good as 8w from an Alpine V12 which would be capable of 40w RMS. Neither amp is going to be stretched, neither amp is going to distort less at such low power.

 

[BRUN]

the headunit will give them 20W rms at very most......

you really need to stick an amp on them, there is no point buying such expensive speakers and then not getting the best out of them by running them off the headunit

its not just a question of loudness, its more about quality, clarity, depth.......basically the whole sound will be a lot better off an amp

 

[Big G]

Was out in the car this morning with a sound pressure level meter to hear exactly how loud the 182 OEM speakers were at a "louder than normal" volume and it measured 90 db peaks with 85 db continuous SPL at one metre inside the Clios cabin.

Now, bearing in mind the sensitivity of the Focal Polyglass units are 91 db (for 1w), that puts into perspective the continuous power required from the amp for the sound level required to produce 91 db which was beyond the volume / sound pressure level I require for "louder than normal".

My next test is to hang a volt meter off the front speaker terminals to measure the continuous and peak voltages provided to the speakers from the headunit, at that volume level. Then, ill view the signal with an oscilloscope to check for any clipping.

Ill keep you posted!

Im thinking "no amp" at this point in time, but id like to compare just to see.

 

[BRUN]

your mental mate, dont bother goin to all that trouble and fit an amp, the comparison between amp and no amp is huge when you actually listen to them

 

[Big G]

Its an additional outlay that I dont want to spend cash on unless its absolutely necessary.

Other than more juice at high volume to the speakers I really dont see the point.

What sort of amp would you recommend? I thought that http://www.caraudiocentre.co.uk/product.asp?product=20155this would do the job just perfectly.

 

[Djw John]

Thats the 4 channel amp Gaz, Ive got the exact same one but was considering swapping for a 2 channel as I no longer use rear speakers!

If you are gonna spend decent cash on good high quality speakers then amp them up because they will run clearer without pressuring the internal amp. If you have a amp that runs at 100w rms or a hu that runs at 20w rms and the speakers need 20w rms then by using an amp with the gain turned down the sound will be clearer as its well within its capabities.

I know that youll be a bit annoyed that the Alpine wont run them to their full capacity but a good hu is a good hu regardless of if you use the internal amp or not. Your pre outs and signal processers will coontribute to sound quality so a good hu is still essential.

Gimme a bell over the weekend if what ive just writen is utter sh*te (which i suspect it is!!)

John

 

[Big G]

Righty then John, amp it is.

I was thinking 4 channel may be better in the long run so that ive got the option of having rears down the line?

I was thinking the same - great components up front and the Vibe 12" sub in the boot. It seems to be the most recommended setup in the Clio, but id perhaps like to put rears in at some stage.

If you wanna offload the 4 channel and get a 2 channel im sure we could come to some arrangement

 

[Djw John]

Mmm possibly! Have you had a listen to mine recently? If not do you want to! Ill be free tommorrow at some point and then not working till August! Gonna get me a student job in the mean time. BTW you on msn?

 

[Big G]

Yeah mate thatd be great to give them a listen, ill be in touch.

 

[Big G]

Its done, speakers/amp ordered:

Focal Polyglass 130V2 Components.
Alpine MRP F240 4x40w RMS.

Decided on the 4 channel amp to give me flexibility to upgrade the rear speakers if/when I need to, but ill try running with just components at the front / sub in boot in the meantime.

 

[BRUN]

ive had that amp before and its excellent for the cash, good choice !