Upgrade

driller

driller

El Presidente
Staff member
Last year I had the following system installed...

4 RockFord Fosgate HPC 2268 6x8 coaxial speakers - 150 watt
Alpine CDA9847 AM/FM/CD/MP3/IPOD Receiver - 50W x 4
RockFord Fosgate P11254 Subwoofer - 12" - 300 watt/4 ohm
RockFord FosGate P2002 200 watt Amplifier(50W x 2 @ 4 ohm)
Alpine MRPF240 4 channel Amplifier - 50W x 4

This year, I'd like to upgrade the subwoofer and/or amp. It's hard to describe why, after all it does sound good and I did win a competition last year. But it appears at high volume the subwoofer buzzes and perhaps the bass is not as tight as I prefer, kinda mushy maybe? Know what I mean?

What should I be looking for?

A different enclosure?

A bigger subwoofer?

A better subwoofer?

More power?

All of the above?
 
RE: Upgrade

naaa You've got plenty of power. Rockford stuff is awesome. I run Fosgate amps also with an Alpine headunit. I'd try out different brand of subwoofer or a smaller one like 10" or(2) 8"s and make sure you build the box to Exactly the cubic feet the speakers manual calls for with no porting. I found that porting makes the base mushy and soft, for the long hanging boom boom music you often hear comming out of ricers cars. Depends on what you listen to. My tastes go from Zepplin and Pink Floyd to Metalica to Country. Lots of different drum beats and baselines for the lower Hz to contend with.
Visit your fav stereo shop and tell them to isolate a particular sub on thier display, pop in your favorite CD and crank it up with same wattage amp selected on display as youre running for current amps and see how they do.

1995 DK Blue Lincoln Mark VIII
1998 DK Blue Chevrolet 1500 P/U
2004 BLACK/Silver HONDA CBR 600RR
 
RE: Upgrade

I'd go with Bill's ossiliscope method above first though. He beat me to the return post. hehe

1995 DK Blue Lincoln Mark VIII
1998 DK Blue Chevrolet 1500 P/U
2004 BLACK/Silver HONDA CBR 600RR
 
RE: Upgrade

Oscilloscope? Cool, I haven't played with one of them for years. I'll have to check eBay. They're pretty handy tools for automotive works as well.

The 'buzz' and 'mushyness' is more prominent with the trunk open if that means anything. The enclosure is a generic box with no porting. When I get some time I'll have to go to a couple shops and do some comparative listening. I'm wanting to stay with a single sub for the sake of trunk space. I didn't put a whole lot of emphasis on the sub/amp combo when I purchased the system since I was trying to hold down total costs. The shop had a 'special' on the sub/amp/enclosure combo and the installer talked me into a 12" over my original choice of a 10". He said because the car was so big it needed at least a 12" sub. Perhaps I would've been better off with a pair of 10"? Would I be able to drive a pair of 10's with the amp I have?

Back in the day of my automotive audiophile experience, subwoofers were pretty much a rarity. You had combo woofers/mid-range and then tweeters and that was it. I understand 'clipping' and other audio semantics but I am a newbie on automotive subwoofer specifics, particularly the tuning of enclosures and such.
 
RE: Upgrade

Well for the price of a 'scope off of eBay, I could buy a new sub. I'm thinking the sub is underpowered and will be looking for a new amp, perhaps a new sub as well.
 
RE: Upgrade

[div class="dcquote"][strong]Quote[/strong]
...Now if you hear any funny sounds it will be from the panels in your trunk resonating from the sound pressure levels..:)
[/div]

That's the probelem with mods, one thing leads to another. ;) I'm looking forward to it.

I'm gonna keep an eye out for a 'scope. One with digital storage would be an awesome tool for troubleshooting.

I'll be doing the R&R of the amp & sub. I'll have to borrow a good DMM from work to conservatively set the gain on the amp. I'll be putting the sub in the 1.25 cuft sealed enclosure I currently have. The 13Ov.2 is recommended to have a 1.0 cuft enclosure. What do you think the issues would be with the slightly larger than optimum sealed box?
 
RE: Upgrade

[div class="dcquote"][strong]Quote[/strong]
[div class="dcquote"][strong]Quote[/strong]...Now if you hear any funny sounds it will be from the panels in your trunk resonating from the sound pressure levels..:)[/div]That's the probelem with mods, one thing leads to another. ;) I'm looking forward to it. I'm gonna keep an eye out for a 'scope. One with digital storage would be an awesome tool for troubleshooting. I'll be doing the R&R of the amp & sub. I'll have to borrow a good DMM from work to conservatively set the gain on the amp. I'll be putting the sub in the 1.25 cuft sealed enclosure I currently have. The 13Ov.2 is recommended to have a 1.0 cuft enclosure. What do you think the issues would be with the slightly larger than optimum sealed box?
[/div]


Normally The sub can sound too "boomy" and not as tight. In the past ED has been know for good customer service, you could email them and they will be able to tell you if 1.25 is too much or not. It's only a few bucks worth of 3/4" MDF to make a new one if it is.
 
RE: Upgrade

[div class="dcquote"][strong]Quote[/strong]
Normally The sub can sound too "boomy" and not as tight. In the past ED has been know for good customer service, you could email them and they will be able to tell you if 1.25 is too much or not. It's only a few bucks worth of 3/4" MDF to make a new one if it is.
[/div]

Thanks DJ, I'll give them a shout for their opinion of the 1.25 cuft. I suppose 'tightness' and SQ is what I'm really aiming for, so I don't mind doing another enclosure if that's the best scenario.
 
RE: Upgrade

ED said check it out for SQ in the 1.25 cuft enclosure. If not suited, go for a smaller enclosure(1.0 cuft). I already have one picked out. ;)

Quickie question just to double check my rusty audio knowledge.

The amp is rated 900W @ 2ohm and the sub is rated 600W rms. I want to play it safe for now and tune the amp for 450W.

450W * 2 ohm(dual 4 ohm parallel) = 900

900^(1/2) = 30

Therefore I should set the amp's gain to 30V with a DMM?
 
RE: Upgrade

OK, I'm wiring the dual VC subwoofer(ED 13Ov.2) in the enclosure. Is this the proper wiring?

http://www.edesignaudio.com/site/wiring/1dvcparrellel.jpg

It's a dual 4 ohm 13Ov.2 sub to a NINe.1 amp. I don't know why, but I'm confused now because the amp has 2 speaker outputs. Do I do the above hooked up to one speaker output or use one speaker output to each voicecoil? As in...

amplifier
---------
+- . +-
| | . | |
| | . | |
VC . VC
---------
subwoofer
 
RE: Upgrade

You could wire it a number of ways but it depends what the amp is capable of. You are probably safe wiring each coil to the separate terminals. Sometimes the amp allows you to bridge the output into one so that you could wire it the way you have show. That way you get a 2 ohm output (more power).

David O'Donnell
'97 Mark VIII LSC "Maxine II" (RIP Maxine I, 5-16-03)
'91 Mark VII BB "Monica"
'67 Thunderbird "Molly"
 
RE: Upgrade

I had it all figured out how to wire the dual 4 ohm voice coils in parallel for a 2 ohm load. That is until I actually looked at the mono amp and was stumped at the dual speaker outputs. It's the dual speaker outputs that threw me a loop.
 
RE: Upgrade

ED tech set me straight. This is the right way...

http://www.edesignaudio.com/site/wiring/1dvcparrellel.jpg

They explained the dual speaker outputs were internally wired in parallel to make it easier to hook up more than one sub. You simply hook up to either set for a single sub. The dual 4-ohm voice coils are then wired in parallel inside the enclosure for a final impedance of 2 ohms.
 
You must log in or register to reply here.
Back
Top