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Discussion Starter #1
Okay...i've been considering to do this for many days but still dint do it, afraid of burning my speakers the moment I do it....so I think I should ask here for advice first....

Here is the situation....


My HU is a Clarion HX-D2, now playing 3 ways. Both my tweeter and mid are on the A pillar...driving them through Focal FP4.75 (75 W RMS x 4)....the sounds is quite good but not good enought..so I bought Tru T03 4.150 150 W RMS x 4)....Which I hope would be providing headroom I needed so that the mid and tweet would sounds even better...Here are the power specs for the tweet and mid...

Mid Vifa PL11 4 Ohm

Long-term Max Power (IEC 18.3) 80 W

Short Term Max power (IEC 18.2) 140 W



Tweeter Scanspeak Aircirculator

Power Handling
100h RMS noise test (IEC 17.1)* 90 W
Long-term max power (IEC 17.3)* 150 W
*Filter: 2. order HP Butterworth, 2.5 kHz


amps power specs:

Model: T03-4.150
Channels: 4 CH
Frequency Response: 10Hz ~ 60KHz ±1dB
Rated Power: 14.4 Volts DC
T.H.D.: < 0.05%
4 Ohm RMS: 150W x 4
2 Ohm RMS: 250W x 4
4 Ohm Bridged: 500W x 2
S/N Ratio: > 100dB
CH Separation: > 70dB
Input Sensitivity: 0.16mV ~ 4 Volts
Damping Factor: > 700
Efficiency: 65.70%
Fuse Requirement: 120 Amp (Outboard)
Power Supply: 11 ~ 16 Volts DC
High Pass @ 18dB / oct: 50Hz ~ 500Hz
Low Pass @ 18dB / oct: 50Hz ~ 500Hz


My worry is that the headroom seems be on the high side...i needed advice if it is okay for me to drive it using that much extra power compare to the published specs?

Btw my midbass is Seas Lotus Ref RW 165/1 on a Tru B2110 and the sub is SI BM MKIII driving using Orion XTR 900.2 bridge 8 Ohm...
 

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Mid and tweeter dont really need that much power, you should've just kept the Focal.

What exactly is the system doing that you dont like? Sounds like a tuning issue...
 

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Discussion Starter #3
It cant go loud enought....I mean if I crank the volume higher...it started to sounds like screaming and unbearable....
 

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You need a 10x increase in power to hear a Doubling in perceived loudness. Doubling the power is not doing anything for you- what you describe (to me) sounds pretty clear that you are overdriving the amp. Put the Focal back in and turn your gains down. You're basically sending DC to your speakers when it is clipping, so it doesn't matter what amp is doing it, you will just fry them faster with a bigger amp.
 

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Discussion Starter #6
Nope I dint install the bigger power amp yet...as i'm worry it might fried the mid n tweet...that's why im looking for advice here...

I set my gain on the focal using multimeter...by a guide on googling and this forum I learn to set the gain just right before it clipping and then set the gain much lower than the max position....If i remember it right the formula suppose to be P = IV....set this a long time ago...and dont really remember the details...
 

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Voltage (AC setting on DMM) = sqrt(RMS * ohms)

Are there any "sound enhancing" features on the HU turned on? The loudness settings can often cause premature clipping.
 

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"Headroom" is a word that I am seeing too much these days. It means nothing, positive (SQ) or negative (blowing speakers) if your music isn't actually taking advantage of it. It is power that kills drivers, not just an amp that is capable of more power than it is delivering.

P.S. most music actually doesn't have all that much dynamic range, and people who are going around telling us they have 250w or 400w or 1000w RMS per channel on their front stage are just full of s***.
 

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It is power that kills drivers, not just an amp that is capable of more power than it is delivering.
To elaborate on this, it's heat over time resulting from too much power that kills speakers. If anyone actually was listening to 250W of continuous power on their mids, for example, they're not going to have good hearing to keep that up for long if the mids don't melt down first.
 

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What it boils down to if you want louder is you'll have to get larger and/or more efficient speakers. Faital Pro makes a HE 3" & 4" widebander.

What bandwidth are your Vifa's playing?
 

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Discussion Starter #12
Thanks for all the responds...I think I should not be using the T03 to drive the mid and tweeter then....Now i'm crossing the Vifa at 500 hz @ 12 db and 5hz at 18 db, while the tweeter is at 5hz 12 db.....may be I'll have the change the vifa...

Here's the graph for the Vifa

http://www.freeimagehosting.net/jvw97
 

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Do you have a link to the driver also?
 

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Hmmm... how on axis are your mids & tweets? What kind of music starts getting harsh at loud volumes?

It could be the glass causing nasty reflections at frequencies that are sensitive to your ears, plus some piss-poor recordings. :)

Do you have any install pics?
 

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I don't think an amp capable of 150w rms is at all excessive for a good quality set of 80-90w components.

Tweeters are very sensitive to clipping, but not that sensitive to a clean music signal.

Even at high volume, as long as the amp isn't clipping the average power getting to the speakers probably won't be more than 50w or so.

FWIW - I have a pair of $20 50w tweeters as part of my component set and my amp is capable of around 300w rms per side. It is gain limited to 250w at 0db. I don't think I could make it clip if I wanted to. Those tweeters have been fine for a couple years now.
 

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Steve Mantz, in Zed Audio's 2012 install guide, explains that "headroom" is essentially a ******** number that tells you that your amp's power supply is either very poorly designed, or is an unregulated supply.

If your amp does not have a regulated supply, transient peaks in your music may be high enough to clip the output signal, for small periods of time. These add up and will burn up drivers, especially tweeters.
 

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I don't see why you shouldn't use that new Tru amps on mids+tweeters... When playing music, even at full whack, you never use full power longer than a few pico-seconds per peak.
Your mids can handle much longer peaks of 140W, your tweeters can handle much longer peaks of 150W, so I see no risk in using a 4x150W amps on these drivers when tuned correctly.


Isabelle
 

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Steve Mantz, in Zed Audio's 2012 install guide, explains that "headroom" is essentially a ******** number that tells you that your amp's power supply is either very poorly designed, or is an unregulated supply.

If your amp does not have a regulated supply, transient peaks in your music may be high enough to clip the output signal, for small periods of time. These add up and will burn up drivers, especially tweeters.
But then people nowadays prefer those ******** numbers....
 
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