speakers and head unit?

AcurInteg96

Just call me chris.
oh it is my friend. nothing like jammin your favorite tunes and getting a nice massage at the same time. but im currently looking for a new headunit and im kinda torn between another premier or alpine.
 

AcurInteg96

Just call me chris.
looks pretty sweet. never seen preouts like that before. but i like the sleek looks of the premiers. like the DEH-P510UB.
 

xOriginalNinjax

New Member
I'm working on replacing my whole set up right now. I just got a used JVC head unit that isn't horrible, and does the job. I'll probably run 4 Blaupunkt 6.5" with 2 6x9s, and possibly a set of 8s or 10s. After I replace all the speakers, I'll decide whether to keep the JVC or not. I know I'll need a 4-channel, 800w amp to run the 6x9s and subs, but I'm not sure which one yet either.
 


AcurInteg96

Just call me chris.
dont let your subs share an amp with your speakers. subs are power hungry. if you underpower them they will blow. your amp for your subs need to have atleast the power if not more than the combined rms of your subs. i have an all type r system with 1000w going to my 4 6.5s and my 2 1" tweeters and then my subs have 1000 going to them as of now. (2 12inch 4 ohm) then im gonna get another 400w when i put my 6x9s in.
 

xOriginalNinjax

New Member
AcurInteg96 said:
dont let your subs share an amp with your speakers. subs are power hungry. if you underpower them they will blow. your amp for your subs need to have atleast the power if not more than the combined rms of your subs. i have an all type r system with 1000w going to my 4 6.5s and my 2 1" tweeters and then my subs have 1000 going to them as of now. (2 12inch 4 ohm) then im gonna get another 400w when i put my 6x9s in.
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I hate to tell you this, but you can't under power speakers. It's not physically possible. (I actually play bass, and do my own speaker cab design work, and work with subs all the time. You can't under power a speaker.) Yes, they are power hungry, but that would be my point in putting them @ 200w with my 6x9s. I don't want subs that make my hatch rattle, only subs that add to the audio quality. All you have to do is get an adjustable volume (or limiter) in line with all four channels, and run the subs at a higher output than the 6x9s.

Basically, the only way you can "under power" a speaker is by trying to push it too hard with too little power, which causes the amp to clip, putting out a square wave, and over-driving your speaker to it's mechanical limit, but that's easily avoidable. There's a volume control on my head unit, and will be one on my amp, and I will probably put a limiter and HPF and LPF in line.

Sorry to rant, I just HATE when people say you can under power a speaker.
 

AcurInteg96

Just call me chris.
its straight dude. just thought id share some knowlege that one of my installer friends told me. guess they were wrong....
 


TegSox

Super Duper Moderator
Yeah, a speaker isn't underpowered until you try to get it to play louder than it capable of, the volume knob does wonders to control that from happening, lol. That's what blows the vast majority of speakers, not too much power, it's because there's not enough power. The speakers voice coil can no longer precisley control the speaker cone, kinda like a valvespring losing control of the valve when you overrev an engine.
 

xOriginalNinjax

New Member
TegSox said:
Yeah, a speaker isn't underpowered until you try to get it to play louder than it capable of, the volume knob does wonders to control that from happening, lol. That's what blows the vast majority of speakers, not too much power, it's because there's not enough power. The speakers voice coil can no longer precisley control the speaker cone, kinda like a valvespring losing control of the valve when you overrev an engine.
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Actually, that's still not true...here's a write-up from a really good Electrical Engineer friend that actually works in amplification:


As an E.E. in this industry, I have designed speaker products for "several" companies over the past 25+ years, including Genz Benz. I have worked very closely with transducer (driver) engineers and I also designed your amplifier. I have also designed and analyzed pro audio products for some of the largest companies in the country.

I received an e-mail from somebody on the forum asking if your "advice" was indeed true since he owns a rig very similar to yours, and he had been using it for a while and was suddenly concerned that he might be "blowing" his speakers. He forwarded this thread and I understand why he was concerned.

I read your post and it's full of mis-information concerning how speakers work and how power ratings relate to the real world. I am not bashing with any attempt to sell anything... in fact you have already bought something! I am also not bashing the speaker manufacturer since they are free to do whatever they feel they need to do to sell their product. What I am saying is that your comment about damaging any cabinet by underpowering it is false and bad information to others here on the forum.

Speakers (low frequency drivers for this discussion) fail for one reason and only one reason... excessive power. This damage can be either thermal or mechanical in nature.

Thermal failure is the result of too much power causing excessive temperature rise in the voice coil and bobbin assembly, causing a softening of the adhesives, blistering of the former and a breakdown of the wire insulation. Thermal failure can occur when the speaker is used with an amplifier that is rated to large for the duty cycle the speaker sees. If the signal is heavily compressed, the duty cycle increases and the speaker power rating (thus amp size) must be decreased. Another cause ofthermal failure is using an amp that is too small for the job at hand, that amp being driven heavily into clipping. When an amp is driven heavily into clipping, the power delivered to the speaker can be as much as twice the RMS rating of the amp. This is, IMO, the primary reason behind the myth that underpowering a speaker can blow it. The failure mode is still too much power.

The second failure mechanism of a speaker is due to mechanical damage. This is always caused by too much power. It's pretty simple for a manufacturer to determine how much power causes mechanical damage. The problem is putting it into a specification that is useful to the average musician. The mechanical power handling of a speaker is not a fixed number, but varies greatly by decreasing as the frequency decreases. This is due to the mechanical loading that the air mass creates to the drivers and below some point the driver is no longer adequately loaded and flops around like an undamped spring. It's not uncommon for a speaker to show a power rating of 1/4 the original mid-band rating when you approach 25-40Hz. Combine this with a grossly large power amp and you have the single most common cause for bass driver failure.

Also note that an amplifier rated at say 1200 watts "RMS" by definition produces a peak 2400 watt rating because of the conversion factor for a sine wave between RMS values and peak values.

I have attached a good overview of loudspeaker power ratings from my good friends over at Harman. Note their discussion relating to derating for musical applications and their references to such in examples 2 & 3.

http://www.jblpro.com/pub/technote/spkpwfaq.pdf

Hope this helps.

-Aged Horse, engineer for Genz Benz amplification
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AcurInteg96

Just call me chris.
xOriginalNinjax said:
I sense a bit of sarcasm in that statement.

But I'll just let it go, and let you keep thinking what you want. :eek:k:
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not really bro. who wouldn't want someone with that kind of experience and knowledge to build them a stereo setup? and seeing as how your friend has 25+ years experience and my friend is 26 i do believe i have enough common sense to respect experience. :roll:
 

xOriginalNinjax

New Member
AcurInteg96 said:
not really bro. who wouldn't want someone with that kind of experience and knowledge to build them a stereo setup? and seeing as how your friend has 25+ years experience and my friend is 26 i do believe i have enough common sense to respect experience. :roll:
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ah, sorry, I'm stupidly used to everyone on CC who used to be overly sarcastic about everything. It is a lot of fun getting to work with and talk to people with that much experience though. It really makes you learn alot.
 

AcurInteg96

Just call me chris.
its cool dude. i got chewed out on TI for something really retarded. this has to be one of the best forums ive been too. but yeah id love to meet that guy. im always willing to learn something new. especially about something im in too.
 

xOriginalNinjax

New Member
There are a lot of things in the audio field that most people just ignore when piecing things together...if you give me a bit, I can show you why my current preference in speakers is Blaupunkt, and for more than just sound quality...but I'm at work, so I'll have to be sneaky about it, so I don't get yelled at.
 
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