Car aiudio question

Amoeba

Amoeba

Amoeba

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Southport
Hi guys

Spent the weekend putting an audio install into my Rover 200. Everything has gone in nicely but am having a couple of problems with the sound quality from the front speakers (JL Audio C5-650).

The bass is only audible when your head is low down in the car - at driving height you can hardly hear it at all. The speakers are mounted onto an MDF ring which is itself bolted over the existing door hole. The door itself has a good amount of Second Skin Damplifier Pro applied.

What could I do to fix this?? I thought about maybe angling the speaker upwards slightly, but this would be a lot of work and not many other installs seem to do this. I also wondered if I cut a hole in the sound deadening over one of the higher holes in the door this might let some sound out. Finally I wondered if bracing my door with something might help it stop flexing when the bass hits (and cancelling it out). Is this something that is commonly done? :)

I would like to get this fixed as there is a whole frequency band missing from where the sub cuts off to where the front components become audible, and tbh the sound is a bit unpleasant :(

Thanks in advance for any advice :D
 
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Almost positive.. I made an effort when installing to get this right, and when I put the balance all the way over to one side bass doesn't seem to improve.

I did temporarily swap over the wires coming out of the amp last night and tbh didn't really notice much difference :/
 
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Just looked up the spec for the C5 650's, nice speakers, alu basket woofers are good, not cheap tho!

Angling the speaker probably wouldn't make much difference, woofers aren't as directional as tweeters are. It would help if you could grab some pics really. Were they too small to fit in the existing holes as I'm not really sure how you've got the MDF mounted.

Also, what crossover points and slopes are you using?
 
Nope, they weren't cheap! Hehe, and tbh I am beginning to wonder whether they were worth the money I paid for them.. without the sub then they would really not sound that much better than the OEM speakers.

Yeh I didn't think angling them would make any difference.. I have been playing around a bit more and find that when I turn the sub off the 'low down' effect seems to stop, so I guess the extra bass I am hearing when I put my head down is actually from the sub and not the components.

I don't know if I will be able to get any pictures 'til the weekend as I use the car for commuting. Essentially I took the old speaker out (which was also 6.5") cut out a ring of MDF to mount onto the existing hole (MDF's inner diameter the same size as the hole in the door) and then mounted the speaker onto that. The MDF ring is essentially just a spacer. I thought this would give the speaker something a bit more solid and flat to be screwed to than just the metal door.

The sub and components cross over at roughly 150hz. Not totally sure as the amp (Audison SRX3) isn't marked very well. The components crossover was left flat.

I am thinking that my problem is possibly something to do with the door flexing in the opposite direction of the driver, essentially cancelling it out.. Will do some experiments at the weekend to see if I can confirm this hehe.
 
Yeh the amp is an Audison SRX 3.

The seal looked pretty good to me, but was only screw / bolt tight. Didn't bother sealing it with silicon sealent as I thought the seal would be good enough already.

Would it be worth sealing it then?
 
Should be alright, i usually mount a gasket between the door and mdf ring to stop vibration etc and to help a little with the bass, problem being you only have a cheap thin door skin on the rest of the door panel anyways.

Sounds like they are wired correctly and fitted fine, it has to be a HU or amp setting, don't know that amp so can't really help :(
 
Mmm, what material do you use for your gaskets?

The rest of the door is covered in damplifier pro stuff, so is a hell of a lot more solid now than it was.. There are certainly no rattles / vibrations coming from it anyway.

The door isn't totally sealed - there are a few slits towards the bottom I left open for drainage. I wouldn't have thought this would have mattered so much...?

I'm confident it's not a head unit or amp issue, the speakers just don't sound right.
 
Ahh yeh I've seen those. Might look into getting some.

Yeh the speakers are 4ohms and the amp can run speakers down to 2ohms.
 
Tbh if they sound as bad as your making out something bigger is wrong than a small airleak, its an odd one for sure, you seem sure the wiring is correct and the speakers are deffo installed right, amps settings are fine so that only leaves one thing, have you got another set (any set) you can stick in to see if they sound as bad?
 
I'm not convinced the speakers are installed right - this is my first install hehe. I just don't see what could be wrong. I don't know much about car audio ;) I do know lots about normal audio though so should be ok..

Don't have another set to try unfortunately.. am a bit flumoxed!
 
Hi, sorry for not getting back to you sooner, snooker was on! :p

The MDF spacers sound fine, so does everything else really. The only other thing I can think of is some strange cancellation somewhere, and this may be able to be fixed with a little selective EQ. Does it sound like 200-400Hz is down a little?

I've not tried it in cars before but there is an amazing bit of software called ARTA which runs on a laptop, and uses a mic to analyse your room (or in this case car cabin) and it tells you if there are any room modes which can be sorted.

If you have a laptop, mic and soundcard, the software is free so it's worth giving it a go if you can.... Linky: http://www.fesb.hr/~mateljan/arta/links.htm
 
Cheers, will take a look at that software :)

It sounds like anything below ~400hz has been cut back a lot to be honest. It sounds a lot like the driver is playing with no baffle. I am still thinking it could be a problem with the door flexing a bit. Might try and bolt something on to it to brace it somewhat.

Will have a play at the weekend and post back :).
 
Keep experimenting...

It could even be the high pass filter in the passive crossover. Maybe try plugging the woofers straight up to the amp with no passive crossover and see if there is any mid-bass then....
 
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