BillFitzmaurice.info

After all that leak sealing I wonder if you just have a dud driver. 20V should be PDL.

PDL means "pretty darn loud" I take it? Idk, it's hard to say. I need to do some more testing later today. I will let you guys know what I'm hitting for voltage and SPL at certain frequencies inside the car. It was kind of loud I guess but like I mentioned earlier, I just expected a bit more going by everyones impressions on it. It doesn't help when people say that their AT sounds like two 12's with mega wattage going to them... I don't know.

I do still need to remove the OEM sound deadening between the seats and trunk and see if that makes a difference but for now with my head unit settings at neutral along with my amp gain being at neutral (dial in the middle at 0 volts I think), there really isn't much for bass. Like I said though, I will do some more SPL testing later and see what I can come up with. I'm still unsure if I set my head unit up correct either, the manual is a bit vague.

My brother has a 12" infinity reference in a sealed box, and another no name 12" in a smallish ported box off an MTX 802.

I had my single AT connected with about 14 volts max and it was about as loud as his 2 sub setup (no ideal) but the bass was very low and "solid" feeling. I woulnd't say it felt crazy loud like rattling my mirrors and buzzing my roof but it was plenty.

Have you taken it out and measured in your house? I had my AT tested in my basement with 10 volts and it was rattling and buzzing my microwave and stove above on the main floor.

Update:

Today, first thing I did was keep all of my settings on the HU and amp at neutral and play a few songs and some test tones to get the current SPL. During songs I did not monitor voltage going to the speaker but during sine waves I was sending about 5-6 volts to the cab. After I got my numbers, I then removed the sound deadening between the back seat and trunk, kept the seat out for the moment and ran my music and test tones again. Music sounded a little cleaner but the readings were very similar. But, with the test tones, from 30hz to 80 hz, most of the numbers jumped a good 5-6db, I was pretty happy about that : )

While doing those tests, I had disconnected the rear speakers so the bass from those wasn't adding to my AT numbers (of course I did this most of the way through my first set of readings so there might even be a bigger difference between both tests, which is a good thing).

Now, I just need to figure out how to filter out the lower frequencies from my front and rear speakers, at least frequencies below 60hz because what I think might be happening is that the F/R speakers are distorting at lower frequencies causing my ears to think the distortion is coming from my AT. I noticed this with the front speakers, they just didn't sound clean down low, possible distortion which is why my mind is thinking this. They seem to sound fine with no sub hooked up. This is getting to be confusing...

My head unit as mentioned before is the Eclipse CD3100, and my amp is an Alpine MRP-M450. The Manual for the amp mentions that I can set specific frequencies to F/R speakers as well as the Non-Fader (to my sub) but I can't for the life of me figure it out. The manual is very vague on this subject : (

Well, off to work for now. TBC

digital_chris wrote: My head unit as mentioned before is the Eclipse CD3100, and my amp is an Alpine MRP-M450.

You need to turn the bass EQ of the Eclipse off.

Bill Fitzmaurice wrote:

digital_chris wrote: My head unit as mentioned before is the Eclipse CD3100, and my amp is an Alpine MRP-M450.

You need to turn the bass EQ of the Eclipse off.

I can set my X-Over NF, X-Over FR and Non-Fader to pass or on and I can play with the bass frequency and how wide I want it in the Parametric EQ, other than that, I think I'm limited in the tuning for that HU. I don't think I'm missing anything but I could be

page 42 and 43 of your manual says you can change the x-over for FR, and for NF. For the doors and rear deck, cross over at 100-120hz to help clean things up. Also make sure that the "loudness" is turned off.

I have the same sub amp for my AT (MCM 8 ).





Edit to correct the driver.

Tom Smit wrote:page 42 and 43 of your manual says you can change the x-over for FR, and for NF. For the doors and rear deck, cross over at 100-120hz to help clean things up. Also make sure that the "loudness" is turned off.
I have the same sub amp for my AT (MCM .

Yes, the manual says I can but doesn't tell me how to, all I can seem to do is change FR and NF to either "pass" or "on". Also, I should turn the "loud" feature off? Wow, I never thought of that, always seemed to sound better to me with it on. I just did a quick google search on the loudness feature and almost everyone seems to hate it... I'll have to give it a try : )

Btw, were you referring to the "loudness" feature, Bill, when you said to turn Bass EQ off?

digital_chris wrote: I can set my X-Over NF, X-Over FR and Non-Fader to pass or on and I can play with the bass frequency and how wide I want it in the Parametric EQ, other than that, I think I'm limited in the tuning for that HU. I don't think I'm missing anything but I could be

If you have the ability to alter the EQ bandwidth you want it to kill below 100Hz. I assume that the EQ only affects the internal amp and not the output to the sub. If the head has the ability to high pass the output to the internal amp even better, set that to 100 Hz, leave the bass EQ flat.

Bill Fitzmaurice wrote:

digital_chris wrote: I can set my X-Over NF, X-Over FR and Non-Fader to pass or on and I can play with the bass frequency and how wide I want it in the Parametric EQ, other than that, I think I'm limited in the tuning for that HU. I don't think I'm missing anything but I could be

If you have the ability to alter the EQ bandwidth you want it to kill below 100Hz. I assume that the EQ only affects the internal amp and not the output to the sub. If the head has the ability to high pass the output to the internal amp even better, set that to 100 Hz, leave the bass EQ flat.

It's weird because the manual seems to tell me I can set preferred frequencies to the front/rear speakers as well as the non fader (to the sub amp) but I can't figure out how... : /

The only freq I can play with are the ones in the parametric EQ which like you mentioned, only control the front speakers. I'll start by setting the bass at 100hz and see what that does, but I don't know if it's a high pass or low pass... All it says is "The three bands, bass, middle, and treble can be adjusted and each band has frequency level and Q curve to be adjusted. Narrow, Normal, Mid-Wide and Wide for Bass, Normal and Narrow for Middle and Normal for Treble". Any idea on how I should set these?

digital_chris wrote:All it says is "The three bands, bass, middle, and treble can be adjusted and each band has frequency level and Q curve to be adjusted. Narrow, Normal, Mid-Wide and Wide for Bass, Normal and Narrow for Middle and Normal for Treble". Any idea on how I should set these?

I'd turn the bass all the way off, leave the mids and treble flat, and adjust the sub amp for level balance. Then adjust the tones to taste. Hopefully the sub amp is unaffected by the tone controls.

Bill Fitzmaurice wrote:

digital_chris wrote:All it says is "The three bands, bass, middle, and treble can be adjusted and each band has frequency level and Q curve to be adjusted. Narrow, Normal, Mid-Wide and Wide for Bass, Normal and Narrow for Middle and Normal for Treble". Any idea on how I should set these?

I'd turn the bass all the way off, leave the mids and treble flat, and adjust the sub amp for level balance. Then adjust the tones to taste. Hopefully the sub amp is unaffected by the tone controls.

When you say to turn the bass all the way off, you mean the bass in the regular tone adjustment? That would probably kill most of the bass going to the amp to, I believe. I'll double check in a little bit. EDIT: Yes, adjusting the bass in the main menu does decrease level to the amp resulting in lower bass.

Also, my two latest questions are, one, the Non-Fader or subwoofer level in the head unit goes from -6 to +6, is this just an attenuation from full voltge at +6 or do you think "0" is normal and above is a boost and below is a cut? The head unit also has 5v pre-outs, is it a constant 5v out or is that what my non-fader level is for, +6 being the full 5v? I'm unsure about this.

Second, is there a better way to correctly set gain on the amp to match the voltage from the head unit rather than turning it up until I hear distortion? That seems to be everyones way to adjust this. The problem is that the AT gives off little distortion as you obviously know so this probably isn't the best way for me to adjust gain. What do you think?

digital_chris wrote:Yes, adjusting the bass in the main menu does decrease level to the amp resulting in lower bass.

Mine does too.

digital_chris wrote:Also, my two latest questions are, one, the Non-Fader or subwoofer level in the head unit goes from -6 to +6, is this just an attenuation from full voltge at +6 or do you think "0" is normal and above is a boost and below is a cut? The head unit also has 5v pre-outs, is it a constant 5v out or is that what my non-fader level is for, +6 being the full 5v? I'm unsure about this.

You'll have to try. Turn down gain on the sub amp, try the constant 5v...and slowly raise the gain on the sub amp.

digital_chris wrote:Second, is there a better way to correctly set gain on the amp to match the voltage from the head unit rather than turning it up until I hear distortion? That seems to be everyones way to adjust this. The problem is that the AT gives off little distortion as you obviously know so this probably isn't the best way for me to adjust gain. What do you think?

What I did with mine is pick some heavy bass tunes, put the HU sub at +6(the highest), turn up sub amp gain until I was peaking maybe, close to 22v on AT....about 80% gain I think.

The problem is that I don't know if the 5v pre outs throw a constant 5v or if that's what my Non-Fader level is for. I don't know how to measure voltage coming out of the head unit.

And about turning up the gain on the amp, when playing heavy bass tunes, it's hard to measure peak voltage because of the rapid change in LF levels. But, if I play sine waves, I can get a constant reading. The problem there is that when I play sine waves at 40, 45, 50 hz, etc, it is very loud in the car at only 5-6 volts. I wouldn't know when I would be maxing out. If I set my gain to get 10 volts with a 50hz sine wave, I'm sure my music would hit peaks even higher than that and then I would be afraid of over excursion... It just seems like a loose loose situation, lol.

digital_chris wrote:The problem is that I don't know if the 5v pre outs throw a constant 5v or if that's what my Non-Fader level is for. I don't know how to measure voltage coming out of the head unit.
.

That 5v would represent the maximum possible output voltage, and where the speaker is concerned it's moot, as it doesn't see voltage from the pre-outs, it sees voltage from the sub amp output.

If I set my gain to get 10 volts with a 50hz sine wave, I'm sure my music would hit peaks even higher than that and then I would be afraid of over excursion... It just seems like a loose loose situation, lol.

All moot, as voltage output varies constantly according to the program material. You're way over thinking this.