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Old 27th January 2010, 15:47   #31
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Originally Posted by Invinsible View Post
... Morel's are power hungry feed them with more power and they will really shine. Dotech will perform excellent if one feeds them with 150rms each if not the least they will need is 100rms each. ...
Perhaps this needs more explanation for a layman like me to understand, so ...
1. These speakers, like any speakers, are passive components - so one does not associate 'hungry' or 'satiated' with them. That is, they passively obey laws of physics (electrical tech, to be more precise) and take only as much power as their impedance can from a voltage source (i.e. the current that flows through is primarily governed by the voltage at their terminals, and not by the power rating of the amp whether it is 100Wrms or 1KWrms as long as the amp is able to efficiently supply that current)
2. The voltage presented to their terminals (from the XO or the amp directly, as the case may be) is totally dependent on the volume control setting at the source (multiplied by the effective gain pre-amp+amp, which anyway does not vary with the music played), and the instantaneous loudness of the music passage
3. Effectively, then, the power one can push through the speakers is directly proportional to the volume setting at the source. Right?

What I find it difficult to understand with such expressions is:
* Do you mean to say these speakers perform well ONLY when played LOUD (the volume is set high)? I thought the ears hear less detail the louder the incoming sound level is
* Between 150W rms and 100W rms there is a LOT of difference in power, especially when one looks at power on dB scale. So could one look at 80W per channel also (20% discount over your derated figure) as long as the 80W power level does no biological damage, or is derating in principle not acceptable as compared to 150W?

Help, please!
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Old 27th January 2010, 16:12   #32
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Originally Posted by DerAlte View Post
* Do you mean to say these speakers perform well ONLY when played LOUD (the volume is set high)? I thought the ears hear less detail the louder the incoming sound level is
* Between 150W rms and 100W rms there is a LOT of difference in power,
The difference between 100W and 150W is about 2db. Not really a lot.

Just like there are cars that require more fuel to operate effciently there are speakers that require more power to operate most effciently.
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Old 27th January 2010, 16:25   #33
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how about focals K2 .. they have loads of midbass !! and tweeters are good to
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Old 27th January 2010, 23:28   #34
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Originally Posted by navin View Post
The difference between 100W and 150W is about 2db. Not really a lot.

Just like there are cars that require more fuel to operate effciently there are speakers that require more power to operate most effciently.
DerAlte if one gets a sportscar with a high compression engine which requires high octane fuel and one runs it with the normal unleaded fuel what's going to happen, one engine will not perform optimally second in a long run the engine with be affected with problems like knocking and others.

Morel's Dotech are rated at 150rms that's coz the passive xover can handle 150. Feeding these with 80 watts will not have an issue. But when going higher on volume chances are bit of distortion come in between. Distortion can damage the drivers more in longer run than having more cleaner power, which can make them perform at best and make them sound more cleaner. In case of Morel for example when I played the morels with 100rms they performed great but lacked a bit if midbass. Than one fine day I bridged my amp which does 250x2, the midwoofer really opened up, midbass was much better, sounded more tight, the mids were more cleaner, the highs from the MT12 tweeter played with more details. Ofcourse I set the gains much lower compared to the running them at 100rms. Another Good part is the amp stayed a little less warmer when pushed hard.
Your principals are right but at times the practical approach is different. For instance Dyns esotec midwoofer can handle even upto 300rms each as long as its under its safe limit of its xmax. As Navin mentioned the difference between 100 and 150rms will just about 2db or may be slightly less.
If the drivers were running active things would be different with 100rms compared to passive. In which case both tweeter and midbass would get the individual power and the result would be even slightly better than running the comps in passive with 150rms. Some drivers from Seas, scanspeak, dyns, hybrid audio and other high end ones work better with more power.
I would always suggest to feed any comps with power close to its power rating when played in passive. There is definately some difference one will notice in the low end response compared to underpowering them. With more power on tab one can enjoy the music better by not pushing the HU on higher volume, which means less distortion. For instance my Clarion 785 clips at volume 27 with max being 33. I set the gain on my amp where I reach the amps max output at volume 22.
For someone who listens to trance one will tend to push more on volume more often and I don't think distortion is what one wants or rather it's the last thing we need to keep the driver safe. Ofcourse the other other parameters like the xmax, HPF, EQing plays its role too in adding to distortion if not tuned right.

Chirag@ Focals do have very strong midbass but the tweeters are bright and one would need to tame it down, it requires lot of tuning and if done right they can sound really good. but, if one install these anywhere on Apiller and on dashboard one will be adding a lot reflection and there will be lot many dips and peaks in certain freq which can add on to it brightness, in which case tuning them down will be further more difficult task.
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Old 28th January 2010, 13:59   #35
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Originally Posted by navin View Post
I have not heard the new Morels the older ones were slightly lispy which was a bit irratiting on female voices.
the term you are looking for to describe that is sibilant. Sibilance is when the s sounds get more pronounced and sound like sshhhh instead ie kind of like lispy because it creates a harsh edge to the decay of a note and sometimes the end of the musical note sounds as you say "lispy"

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How are Morel in general?
recently i heard some morel pulse which is the older entry level morels and they were decent and i also listened to the Morel supremo's and i have owned the morel ultimo sub, the supremo's are absolutely top notch ... in fact amongst the best speakers available for a car, and the ultimo sub was nice but not what i was looking for in a sub it was too refined and tended to disappear when the car was switched on and being driven and i can directly attribute that to my cars engine being noisier than a normal car since it does have a sporty engine but it was otherwise an excellent sub

Last edited by naughty001 : 28th January 2010 at 14:05. Reason: adding more to reply
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Old 28th January 2010, 19:55   #36
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sorry i could not edit my post above cos its a couple days after the reply above and way past the 20 minute edit limit - but heres a good read on the dotech ovations from Car Audio and electronics (i used to read this magazine avidly when it was being published and im sad they closed down now)

http://www.caraudiomag.com/testrepor...iew/index.html
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Old 29th January 2010, 14:13   #37
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Originally Posted by navin View Post
The difference between 100W and 150W is about 2db. Not really a lot.
In dB induced by the W, especially by efficient speakers, that 2dB is the difference between irrecoverable and recoverable (ear) damage!

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Originally Posted by DerAlte View Post
... any speakers, are passive components ...
Quote:
Originally Posted by Invinsible View Post
... sportscar with a high compression engine ...
Inappropriate comparison from what I was trying to say. A speaker is a (driven) passive element whose output characteristics cannot be controlled by external influence. An engine is a (driver) active component which can be controlled, within limits, beyond inherent characteristics - that is equivalent to an amp!

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Originally Posted by Invinsible View Post
... Your principals are right but at times the practical approach is different. ... Some drivers from Seas, scanspeak, dyns, hybrid audio and other high end ones work better with more power.
...
My bad! Looks like I need to take a course in poetry appreciation to fully appreciate technology.

I thought the correct technical explanation was the sensitivity figure (e.g. xx dB/W @1m into y ohms), i.e. 87dB/W etc. is, in your language 'hungrier', than a speaker with 91db/W. I do understand that this sensitivity figure is for convenience published as a single figure (possibly measured at one frequency), whereas in reality the sensitivity is different at different frequencies (within the speaker's repertoire). Am I close to phrasing it correctly, Navin?
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Old 29th January 2010, 14:53   #38
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Der Alte Sir IMHO a rated maximum input power figure on a speaker is not a finite figure. it is loosely based ont he thermal power handling of the speaker. to say that if the speaker has a figure of 100 watts RMS as its max power handing and then insisting that 100 watts is all it handles is totally ignoring how an amplifier works. The amplifier will not give you a constant 100 watts RMS even though it is rated at 100 watts nominal - this is supposedly the average power output at a certain distortion level but it doesnt tell you what the highest peaks and lowest dips the amp takes

the amp could be actually giving a speaker mostly 10 watts RMS at its lowest dips with peaks of 150 watts at times whilst another amp rated at 100 watts RMS could be giving a speaker dips of 5 watts and peaks of 300 watts but fewer peaks and still be averaging 100 watts nominal

also we know that an amp will not be providing clean power all the time. at certain power levels (sometimes even close to its nominal ratings) it could be giving you clipped signals hence this is where headroom comes in ie you want a higher figure than the maximum rating at all times hence an amplifier that provides more power than the speaker is rated for is an advantage since it is less likely to clip at the maximum power handling of the speaker

the thing is though you need to be able to hear when the speaker is distorting and hence limit the volume at that level to prevent the distortion. The extra power is considered to be headroom and this headroom will rarely affect speakers unless you pick up the volume levels too high so its not power that kills speakers but rather the "nut behind the wheel" so to speak (the wheel in this instance being the volume control)

certain speakers for example Dynadios and MB Quart - which i have used recently seem to soak up power when it is applied. i have used amplifiers rated at 200 watts RMS on the tweeters and these have caused no adverse effects on the equipment and in actual fact they just play better and richer than when fed with less power but straining because you want to pick up volume levels for the output levels you desire.
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Old 29th January 2010, 14:59   #39
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Originally Posted by naughty001 View Post
the term you are looking for to describe that is sibilant.
the supremo's are absolutely top notch ...
Yes Siblance! Thank you.

The Supreme and Supremo are excellent tweeters but they fall in a very different price range.

Quote:
Originally Posted by DerAlte View Post
that 2dB is the difference between irrecoverable and recoverable (ear) damage!

I thought the correct technical explanation was the sensitivity figure (e.g. xx dB/W @1m into y ohms), i.e. 87dB/W etc. is, in your language 'hungrier', than a speaker with 91db/W. I do understand that this sensitivity figure is for convenience published as a single figure (possibly measured at one frequency), whereas in reality the sensitivity is different at different frequencies (within the speaker's repertoire). Am I close to phrasing it correctly, Navin?
Hearing loss is dictated by the average SPL as well the lenght of exposure.

Every manufacturer has a different method used to measure sensitivity which is why you might find a 88db/1w/1m speaker from one manufacturer to be more efficeint than a 90db/1w/1m speaker from another. I really wished that they had some standards - if it is was me I'd have used the MOL standards as a template. Today the best judge is to get the Force Factor and divide that by the Moving Mass (Mms).
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Old 30th January 2010, 01:16   #40
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I suppose Naughty has answered what exactly was on my mind. Thanks Nitin.

In addition to that a simple example will be powering 50Rms comps playing directly to the headunit which may give out 18-20rms. What happens when we push the volume to listen to the desired output? Well we all know the answer for it, distortion/clipping will come in the picture once you go higher up. Everything will seem fine on lower volume but as one goes higher on volume one would be sure of that the speakers are distorting.
Solution well, we all suggest to add an amplifier. What do we get out of it, power them with exactly 50rms chances are they will play cleaner, will have better midbass, mids, highs. One can even go higher up on the volume and it will still sound clean until the driver reaches it mechanical limit.
Not that a 100rms comp will not work with 50rms amp but it's just that when going for the desired output there are chances one may be pushing the amp to its limit thereby chances of sending clipped signal is higher.
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Old 30th January 2010, 10:41   #41
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Thanks, navin, invinsible and naughty (perfect description of power needs!), that was what I was getting at. It never serves the purpose of making people understand the issue if we describe a situation with phrases like "hungry" and "soak up power", especially when someone is comparing speakers. I am sure you see enough instances here of putting the cart before the horse - assuming that xxxW of power is absolutely compulsory to get good music.

Last edited by DerAlte : 30th January 2010 at 10:43.
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Old 30th January 2010, 11:11   #42
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Originally Posted by DerAlte View Post
- assuming that xxxW of power is absolutely compulsory to get good music.
I have been crying myself hoarse (over the past many years) to convince people not to use the Watt ratings (especially the advertised ratings) as anything more than a very approximate guide.

one-way-linear-Xmax, Bl/Mms ratio, Cms, etc.. give you a better indication of the speaker's ablitiies to handle power and delvier SPLs.
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Old 30th January 2010, 11:22   #43
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Navin, it all starts with the 'desire to get a powerful system'. And the desire is fed by unclear / esoteric treatment of the issue of required power. We need people like invinsible and naughty to spread the word in such a way that the main issues are understood properly even by people who are hearing the terms for the first time.

I think it is time we started a sticky thread and put your and other members' expressions on this subject in one place.
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Old 30th January 2010, 11:45   #44
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Originally Posted by navin View Post
I have been crying myself hoarse (over the past many years) to convince people not to use the Watt ratings (especially the advertised ratings) as anything more than a very approximate guide.

one-way-linear-Xmax, Bl/Mms ratio, Cms, etc.. give you a better indication of the speaker's ablitiies to handle power and delvier SPLs.
Agreed. But the other factor is at what xover point the driver is crossed that matters. Learning about mechanical limitation definately helps to derive whats the safer xover limit for the driver at a given xxx power. Most people even tend to cross the drivers below their resonant freq. which may or may not work provided one doesn't touches the excursion limit. Some drivers with lower VAS value and higher xmax are even capable of handling more power than their rated output provided they are not crossed too low. Simple example could be peerless SlS6, Dyn midbass, Creative sound's Trio8.
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Old 1st February 2010, 04:43   #45
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Originally Posted by DerAlte View Post
Navin, it all starts with the 'desire to get a powerful system'. And the desire is fed by unclear / esoteric treatment of the issue of required power. We need people like invinsible and naughty to spread the word in such a way that the main issues are understood properly even by people who are hearing the terms for the first time.

I think it is time we started a sticky thread and put your and other members' expressions on this subject in one place.

Im not 100% sure that our comments are actually sticky worthy as they stand, since it will always be a matter of opinion and always remain subjective. Some people will swear by sticking to matching ratings whilst others will be convinced that less is better whilst others like myself will take the Jeremy Clarkson view and scream for "Moar ppooowwerrrrr"

to the opening poster sorry we went so - that wasnt truly the intention but we just all got sidetracked a bit

oh and Der Alte sir .... i just reread your point on differing sensitivities at differing frequencies - i missed that on the first reading, and yes you have a hugely valid point there as well, so thanks for pointing that out as well

Last edited by naughty001 : 1st February 2010 at 04:53.
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