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Old 31st January 2014, 14:06   #16
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Default Re: Matching HU amp power with Speaker power?

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Originally Posted by DerAlte View Post
would you not buy the car if the speakers were not sensitive?
You should be moreworried about the power level (electrical) at which the amp driving them starts distorting. The amp, especially an HU-internal amp, is more likely to nastily distort at high output levels than the speakers.
I guess you meant would I not buy the speakers if they were not sensitive. Well I was already worried with those Blaupunkt specifications I put up for a few reasons;

1. Impedance mismatch to the stock speaker.
2. Thrice the requirement of power over the stock speakers.
3. Unknown sensitivity values of the stock speakers.

My extended "loud" session lasts no longer than 5min at a stretch and my idea of loud, as I said, is nowhere near ear splitting level. If you've heard the hopeless stock stereo from a Linea/Punto, my volume number never exceeds 10 and that is quite loud for me.

How reliable are the Frequency response values published for car speakers? I picked those Blaupunkt's cause they go down to 40Hz and bass (actually all frequencies sound muddled) is what is missing with the stock speakers. I do understand that it also depends on the frequency response and quality of the head unit to be able to effectively play so low.

If you say the head unit amplifier section starts to distort at higher gain, this should be audible right?

Last edited by sandeepmohan : 31st January 2014 at 14:07.
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Old 31st January 2014, 15:17   #17
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Default Re: Matching HU amp power with Speaker power?

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Originally Posted by sandeepmohan View Post
I guess you meant would I not buy the speakers if they were not sensitive. Well I was already worried with those Blaupunkt specifications I put up for a few reasons; ...
I meant no one buys a car analysing speaker sensitivity. Buying OE speakers is a decision anyone would rue!

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Originally Posted by sandeepmohan View Post
... 1. Impedance mismatch to the stock speaker. ...
Impedance governs how much power can be pushed through by the amp. 3ohms v/s '4ohms' is not a major issue - it is 3.xx ohms. Also, a 3ohms speaker with less sensitivity will sound as loud as a 4ohms speaker with higher sensitivity.

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... 2. Thrice the requirement of power over the stock speakers. ...
Huh? Where did you find that number?

The power number is not a 'requirement'. It is the maximum power that can be pushed through the speaker coil without distorted sound coming out. Max. power is the power that can be pushed through without the voice coil being in danger of going extinct!

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Originally Posted by sandeepmohan View Post
... 3. Unknown sensitivity values of the stock speakers. ...
As I said earlier, it doesn't matter when one is just replacing speakers - just set volume slightly higher. It matters only when one is doing system design for an SQL system. At normal consumer levels it don't matter much.

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Originally Posted by sandeepmohan View Post
... the hopeless stock stereo from a Linea/Punto, my volume number never exceeds 10 ...
Listen to it with after-market speakers. The HU is not that bad. You may have to put the volume at 11 or 12, but these speakers will sound much better than the OE ones did

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Originally Posted by sandeepmohan View Post
... How reliable are the Frequency response values published for car speakers? ...
With a fistful of salt, garam masala and maybe a dash of coriander leaves!!! These are always testbed figures measured in an anechoic chamber. A real car is a diffferent ball game.

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Originally Posted by sandeepmohan View Post
... If you say the head unit amplifier section starts to distort at higher gain, this should be audible right?
Yes, it will be very audible. Most times we are too immersed in music to notice it though. Usually speakers can take much more power than OE HUs put out, and faithfully reproduce the amp distortion.
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Old 31st January 2014, 23:09   #18
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Default Re: Matching HU amp power with Speaker power?

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Huh? Where did you find that number?
20 watt is printed on the label stuck behind the magnet of the stock speaker unit.

Nominal power handling and maximum power handling are both published on the Blaupunkt website for each of those speakers I listed. I was referring to this.
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Old 3rd February 2014, 13:46   #19
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Default Re: Matching HU amp power with Speaker power?

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20 watt is printed on the label stuck behind the magnet of the stock speaker unit. ...
Got it - that is what is to be expected with 14-18Wrms max that the internal amp can put out.

I had got confused by the term "requirement" in your sentence "Thrice the requirement of power over the stock speakers". There is no 'requirement' as such, since that would mean that much power is required at least to drive the speaker. Those power figures are "please don't exceed" figures.
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Old 3rd February 2014, 21:28   #20
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Default Re: Matching HU amp power with Speaker power?

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Those power figures are "please don't exceed" figures.
If the nominal power rating for the after market speaker is in the range of 50-62 watts, won't that we pushing the internal amplifier of the stock head unit considering it drives a 20watt stock speaker unit?

Most manufacturers are highlighting both nominal power handling and maximum power handling. I guess when you say "please don't exceed" figures, it should be referring to the maximum power handling.

As an example, the Blaupunkt CX160 has a nominal power handling of 62watt and maximum power handling of 260watt. Will I not end up pushing the stock head unit amplifier?
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Old 4th February 2014, 15:34   #21
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Default Re: Matching HU amp power with Speaker power?

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Originally Posted by sandeepmohan View Post
If the nominal power rating for the after market speaker is in the range of 50-62 watts, won't that we pushing the internal amplifier of the stock head unit considering it drives a 20watt stock speaker unit? ...
No. What goes through the speakers is what the music demands (based on volume control setting), not what the speaker is rated.

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Originally Posted by sandeepmohan View Post
... Most manufacturers are highlighting both nominal power handling and maximum power handling. I guess when you say "please don't exceed" figures, it should be referring to the maximum power handling. ...
* "Nominal" is the highest power one can push through the speaker without the speaker distorting (usually non-linearity at the end of travel of the cone)

* "Maximum" is the highest power one can push - distortion notwithstanding - that will be thermally safe for the speaker voice coil. All speakers have a slight bit of functional inefficiency - some of the energy gets converted to heat. Under normal circumstances, air circulating around magnet and voice coil takes away this waste heat. If the heat produced is more than heat taken away, temperature of the voice coil is likely to make it fail - insulation burning causing electrical short-circuit

These are the 2 "please do not exceed" power numbers!

Quote:
Originally Posted by sandeepmohan View Post
... As an example, the Blaupunkt CX160 has a nominal power handling of 62watt and maximum power handling of 260watt. Will I not end up pushing the stock head unit amplifier?
I think you are misunderstanding "power".

* Speakers don't pull power - the amplifier pushes power (puts up a voltage at output which pushes a current through the speakers' voice coils)

* Power is not constant - it depends on what music is playing, and how loud you are playing it
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Old 25th March 2015, 16:18   #22
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Default Re: Matching HU amp power with Speaker power?

I finally got a pair of speakers installed on my Linea. Yes; it took this long, post our last discussion. It just went off my radar.

I approached the trusted car audio folks EB BASS in my city. I took their recommendation. What started off as a 10-12k budget ended up at 24k including installation. The speakers alone were about 21.5k.

1. Diamond Audio DE65V for the fronts
2. Diamond Audio DE652 for the rears

The other, much cheaper option was some unheard of brand called Acustika Audio. A pair of AK-SA6.5C and AK-SA6.5. Both would have set be back just 12-13k with install. I was hesitant so stuck with Diamond Audio. I approached EB BASS under the impression that I would put in some mainstream stuff but they had absolutely none. Morel, ARC Audio and a couple of others brands were the options and super expensive stuff.

EB BASS suggested I pair along a amplifier but I decided not to as a first attempt. With the complications associated with installing an amplifier in a Linea running a stock head unit, I was worried about this too. I burnt my fingers big time on my previous car by spending half a lac on a all Blaupunkt Velocity setup and then dumped all of it for a song to FM reignofchaos. While all the components were good, the car acoustics were very poor.

No damping was done. A wooden speaker mount frame and some extra speaker wire was used in the install. It was done well. The good thing about the Diamond Audio components were the fact that the cross over is integrated in to the mid bass driver so no additional box hanging around inside the door frame. Lesser chance of a rattle.

The sound is absolutely amazing. There is a little bit of that trade mark head unit sound signature still audible but there is little I can do about that. Be it at the front or the rear seats, you get well balanced audio. I need to crank up the gain a bit more than stock speakers.

The challenge with my car is to get rid of road rumble that filters in to the cabin due to the 205 section tires. This kills a ton of the audio quality. I have to crank up gain even more. Still; there is a definite loss in detail when on the move.

On the overall, I am super happy. Thank you for your guidance.

Last edited by sandeepmohan : 25th March 2015 at 16:22.
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