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The sub amp is the sub section of the ZX700.5

The gains were set to about 75% - I knew I would not be overpowering that sub, and in tuning with with front stage, this is what worked best. 880PRS sub channel set to 0db or +1-2db depending on the music program.

I will test my charging system, but its strange that it only happens when the amp gets hot. And its stranger still that the amp gets hot running 8 and 4 ohm loads.

Kicker has provided an RA so its going back, I will fight them for a new one, but who knows what they will tell me...

Thanks again for all of your input...I will keep everyone updated.
Gains set to about 75% doesn't tell us the gains have been set correctly.
Try to do a search (on the forum) about gain settings.
You might be clipping the sub output which might explain why the amp gets so hot.
Wiring the amp from 2 ohm to 8 ohm, you did lose some output - then upping the gain to make up for the loss of output.

Again, search about gain settings - no offense, just a suggestion...

Kelvin
 

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I said loudness and efficiency (which is sensitivity, ie. how efficiently the driver converts electrical power into acoustic power).

I think you are confused between the sensitivity of the driver compared to how loud it can get off of an amp driving a 4 ohm load at a certain wattage and then halving that output when it bumps up to 8 ohm.

In this case, the speakers are as sensitive as each other assuming the speakers are like the ones in the posts above. The 8 ohm one will however cause the amp to put out half(ish) the rated power of 4 ohms causing the 8 ohm driver to be 3dB less loud even though it has the same efficiency/sensitivity.
IMO this is why this thread confuses people. Maybe I don't understand this stuff yet but given the choice between an 8 ohm driver and the same one in 4 ohm, I would pick the 4ohm. The sensitivity increase in the 8 ohm driver is usually .5db not 3db, so all you are really doing is halving the power when you choose the 8 ohm route.

The main example has the 8 and 4 ohm driver with the same V rating, which pretty much never happens. The 4 ohm is generally 3db higher in the same driver. So while the first example is technically correct it suggest to the average user that the 8ohm version of the same speaker ends up having the same output as the 4ohm which isn't true. Sure, it will be less than 3db down compared to the 4 ohm speaker, but the 4 ohm driver will be noticeably louder.
 

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^ this is what confuses me also.

If I have the choice of 2 identical drivers:
1) 4ohms at [email protected]/M (50W RMS)
2) 8ohms at [email protected]/M (50W RMS)

Both would be power by a 45W RMS powerpack. Which would be the better choice?
Depends... Does your powerpack do 45W @ 8 ohm and 45W @ 4 ohm?

Kelvin
 

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It's 4 channel, [email protected] not bridgeable. There is only a high/low gain switch. So I'm guessing that it will not supply much power to the 8ohms speakers and the 4 ohms would be the better option.
You got your answer all by yourself ;)

Kelvin
 

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It's 4 channel, [email protected] not bridgeable. There is only a high/low gain switch. So I'm guessing that it will not supply much power to the 8ohms speakers and the 4 ohms would be the better option.
The 4 ohm model would be better.

See post #30 in this thread:

If both are rated 1w/1m you need to be 3db higher sensitivity to get the same output with 8 ohm vs 4 ohm
So based on that, for the 8 ohm version to be of any benefit, it would need to have a sensitivity of at least 93dB or higher for your situation.
 

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Thanks to the Original Poster for answering my NOOB dumb question.

I am about to start my first install, and because I'm not really ready to do the whole thing yet, I figured I might power up the 4 Ohm 2-channel amp and run it to some 8 Ohm home speakers I have laying around. Seems like I'll be fine (for the time being, until my 4 Ohm speakers show up in the mail.

Thanks again.
 

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So, if I was to have a JL AUDIO 300/2 (150x2 @ 1.5-4 OHM's) and a pair of Peerless XLS 8" (10MM XMax)with a DB of nearly 91DB and a pair of HAT 6 1/2 Clarus (12MM XMax) with a sensativity of 90.4DB, the Peerless should have more output due to it's cone area, right? What if the Peerless was a 6.5" just like the Clarus, would the Peerless still have equal output on 75 W since it's 8 OHM's?
 

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So, if I was to have a JL AUDIO 300/2 (150x2 @ 1.5-4 OHM's) and a pair of Peerless XLS 8" (10MM XMax)with a DB of nearly 91DB and a pair of HAT 6 1/2 Clarus (12MM XMax) with a sensativity of 90.4DB, the Peerless should have more output due to it's cone area, right? What if the Peerless was a 6.5" just like the Clarus, would the Peerless still have equal output on 75 W since it's 8 OHM's?
Use the formula's given on the first page (first post or post #1). That should give you the answer or atleast a better idea.
 

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Use the formula's given on the first page (first post or post #1). That should give you the answer or atleast a better idea.


I'm fairly new at this technical stuff and it just went over my head. :/ Maybe I can find someone that can help me out on this. Thanks
 

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This thread helped me make a decision to get a pro audio driver for a midrange. I got in on the pre-purchase of the Melodic Acoustic Intimid8r 8" midwoofer and wanted something that would be a similar sensitivity as it. I ordered a pair of Faital Pro 3Fe22 8 ohm drivers. Still not sure what I'm going to do for a tweeter.

My question is will I be OK running these on 2 channels of my PDX-F4? It was specd at 121 watts per channel @ 4ohms. Do I have a chance of running them on the F4 or is it just gonna be too much even if the gain is down?
 

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This thread helped me make a decision to get a pro audio driver for a midrange. I got in on the pre-purchase of the Melodic Acoustic Intimid8r 8" midwoofer and wanted something that would be a similar sensitivity as it. I ordered a pair of Faital Pro 3Fe22 8 ohm drivers. Still not sure what I'm going to do for a tweeter.

My question is will I be OK running these on 2 channels of my PDX-F4? It was specd at 121 watts per channel @ 4ohms. Do I have a chance of running them on the F4 or is it just gonna be too much even if the gain is down?
Yes..it's ok.

They'll appreciate the headroom
 

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Thank you.

I know when to back off the volume knob most of the time. I'm usually not trying to power them with close to 3x rated power though :)

I suppose they're not too expensive if I burn them up. I'm also having second thoughts about them. I just learned about QTS and enclosures. These may not be ideal for ib in a door. Suppose it can't hurt to try it and see. Cars are really weird environments for sound so anything is possible.

Then you have the fact that I'm attempting my first active system. I wonder how long the Bit One is gonna take to learn :) I know just enough to make me dangerous and I have all the tools needed.

...and it's a 3 way plus sub at that. LOL

Wish me luck!
 

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I came across this thread related to an issue I encountered last week. I used to come here a lot 10 years ago or so.

I am still struggling to understand the concept. My 2013 Charger SRT8 Superbee has the Alpine 6 speaker ~260W system. It has 3.5" dual cones in dash, 6x9 mids in front doors, and 6x9 2-way in the rear deck. I already replaced the whole front stage. The factory impedance for all 6 corners is 2 ohms, I have verified this at 1.7 ohm dry out of car. My Kicker 3.5" 2-way upgrade in dash seemed to work well. I lost no volume, and the highs are much more noticable. It also brought up my stage height quite nicely. Probably because its a couple 4 ohm's wired in parallel to keep the factory resistance the weak factory amp likes. Where I had a big problem is when I did the Kicker 6x9 1-ways into the front doors. They are confirmed 4 ohm. (3.6 ohm dry). They were not even detecable anymore, and the rear deck 2-way 6x9's completely overpowered the whole car, bringing my stage to towards the back seat. I put my stock 6x9's back in shortly after that to restore the balance.

I was going for a very minor upgrade, no interest in changing any amps or decks. So per the first post in this thread, how is the 4 ohm speaker going to match the volume and quality, when I am used to a 2 ohm volume level? I have no idea what the sensitivity rating is on either speaker, all i know was the volume was cut in half. I don't want to swap out the rear 6x9's also, as then all 4 6x9's would be much quieter and my dash speakers would move into the overpowering role.

I did check PartsExpress for any 1-way 2 ohm 6x9's and found nothing. I like 6x9's and don't really want to switch to 6.5", this car is a lease. As minor modifications as possible.
 
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