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View Full Version : Midbass problem. Doors are the culprit?



sjv13
12-19-2013, 01:35 PM
So I have a feeling my doors are severely limiting the midbass output from my front door woofers. Even with the HPF set to 50hz, I have very little midbass. My mom's stock system (no factory amp or anything) in her Toyota Avalon puts out way more bass than I can with a set of $300 6.5" Focals and a Polk PA660 4 channel (75x4). I've included some pictures of my doors, and I'm pretty sure the problem is that since there is such a small amount of airspace that the woofer is sitting in, it essentially gives it the smallest enclosure known to man and makes it roll of at a pretty high frequency. For example, snare drums sound incredible, but anything below that frequency is very subtle. I have my components and sub xover'd at 80hz.

I also went to the somewhat local car audio/custom shop, and they said they could cut out the layer of metal right behind the speaker's magnet and install a wooden baffle (far superior to my closed cell foam baffle, lol) to try to give the speaker a bit larger of an enclosure and use the rest of the door's airspace. They said they'd do both front doors for $130.

So I'm here to ask you guys, do you think this will solve my midbass problem? Or is the guy just saying that it will help because he wants to make a quick buck? I don't really feel comfortable cutting my doors myself.

You might notice the layer of fluffy stuff, but it's just a really thin layer and the metal piece is right underneath it.

Photo gallery:
Door speakers - Imgur (http://imgur.com/a/pmrii)

bradl79
12-19-2013, 02:32 PM
Deadener may help. U may be getting a lot of flex

sjv13
12-19-2013, 02:43 PM
Deadener may help. U may be getting a lot of flex

I feel like my biggest issue is airspace though. Am I wrong?

T3mpest
12-19-2013, 03:18 PM
Once you put the doorskin, that entire space is still acting as an enclosure. However, it's probably not helping the way it is now, does your speaker have a vented pole piece on the bottom? If so then yes, you def need a inch or two of space behind it, if it's a closed basket, not as much. Your closed cell foam baffle is likely not a great seal though. I'd try and build some wooden ones, if you can't do it yourself, your shop said they would.

Next thing to PLEASE realize, is 50hz is not midbass. Your moms speakers may put out more "bass" becuase they probably aren't crossed over. That is NOT midbass and never will be. Snares can be midbass, but there is treble in that region too. Good midbass is not subbass from your mids. If you want that, you'll basically always be disappointed.

bradl79
12-19-2013, 03:51 PM
Plus ur moms speakers are paper cones. I got more bass in my stock than I do in my CDT speakers but that's what good ssub's are for. The bass does not drown out the highs like it would with our moms stock speakers. The same is with my gf. Her speakers have good bass but dies drown out the mids and its not a booming bass. Do u have a sub?

sjv13
12-19-2013, 05:00 PM
Once you put the doorskin, that entire space is still acting as an enclosure. However, it's probably not helping the way it is now, does your speaker have a vented pole piece on the bottom? If so then yes, you def need a inch or two of space behind it, if it's a closed basket, not as much. Your closed cell foam baffle is likely not a great seal though. I'd try and build some wooden ones, if you can't do it yourself, your shop said they would.

Next thing to PLEASE realize, is 50hz is not midbass. Your moms speakers may put out more "bass" becuase they probably aren't crossed over. That is NOT midbass and never will be. Snares can be midbass, but there is treble in that region too. Good midbass is not subbass from your mids. If you want that, you'll basically always be disappointed.

What do you mean when you say, "Once you put the doorskin, that entire space is still acting as an enclosure"?

Also, I'm not trying to get subbass from my door speakers. I'm just saying that even when I run them with a HPF at 50hz, they don't put out much of any midbass still (or subbass, but I don't really expect that to happen anyways). For some reason it's just hard for me to grasp that stock speakers running off of HU power can put out a fuller freq. range than aftermarket speakers on an amp when both are run full range (or pretty close to full range, at a 50hz hpf in my case).

Here is a good picture of the back of my speakers: http://www.top-elektronik.at/images/product_images/original_images/actindo_focal_integration_is165.jpg

I know the foam isn't a very good baffle, but it is a decent seal (of course not as good as an mdf baffle, but still pretty decent).

bradl79; yes, I have a sub. Alpine type r 12 on 500w.

I find that I get more of the midbass kick I'm looking for when I let the sub play a little higher, with everything xover'd at 100hz. But that point, localization starts to occur.

keep_hope_alive
12-19-2013, 05:41 PM
i understand what you are asking. good job with the foam to create a seal against the panel. what you are experiencing is cancellation as well - the rear wave just reflects and comes back out through the cone out of phase. opening up the rear of that "enclosure" will help. but then you have the entire door cavity to deal with. totally worth it though and I don't see the need to rebuild a new enclosure out of wood. just open it up to the door cavity at the rear (keep the top part for water protection.

making a wood baffle for the front may be a good idea to ensure you don't have any air leaks - but you can test that with some low frequency tones.

Side Show
12-19-2013, 07:50 PM
dynamat & cover access holes with mdf and dynamat too

sjv13
12-20-2013, 11:12 AM
i understand what you are asking. good job with the foam to create a seal against the panel. what you are experiencing is cancellation as well - the rear wave just reflects and comes back out through the cone out of phase. opening up the rear of that "enclosure" will help. but then you have the entire door cavity to deal with. totally worth it though and I don't see the need to rebuild a new enclosure out of wood. just open it up to the door cavity at the rear (keep the top part for water protection.

making a wood baffle for the front may be a good idea to ensure you don't have any air leaks - but you can test that with some low frequency tones.

Ahh, I see what you're saying. So I'll have that shop cut out the metal (leaving the top in) and then I'll probably just have them install some mdf some baffles in there for cheap too. It will allow some flexibility in speaker choice that way, as well as provide an air tight seal. Should I have them put a couple sq ft of dynamat right behind the woofers to try to cancel some of that rear wave?

keep_hope_alive
12-21-2013, 09:35 AM
dynamat won't cancel anything. it just lowers the duration of resonance. nothing more.

my build logs show my pvc encased fiberglass batt concept that helps absorb rear waves.

Jroo
12-23-2013, 09:16 AM
looks like a volvo door. when i did my v70 they did pretty well even without deadner. Volvo doors are pretty tank like. It may be speaker dependent, but I was never able to get a midbass in the door to play lower than 70hz. I also tell people to really listen to the factory system you are comparing it to. Some factory systems are eq to be bass heavy and they dont really do it well. They play but are usually muddy and some distortion while doing it. I would deaden your door, pull some of the polyfill out to open it up and raise your xover point. I think you will like the results then.

SamIam71
12-23-2013, 10:14 AM
Speaker Tweaker Kit - SSA STORE (http://store.soundsolutionsaudio.com/products/speaker-tweaker-kit.html)

These sort of look gimmicky to me, but maybe someone else has some experience with them.

keep_hope_alive
12-23-2013, 12:31 PM
Speaker Tweaker Kit - SSA STORE (http://store.soundsolutionsaudio.com/products/speaker-tweaker-kit.html)

These sort of look gimmicky to me, but maybe someone else has some experience with them.

yes it is a gimmick and only works for higher frequencies. midbass won't even see it. think of it this way, in order to be affected, a product needs to have a depth of 1/10th wavelength to 1/4th wavelength.

nismos14
12-23-2013, 01:24 PM
Remove the stuffing that's in there, and try reversing the phase on ONE of your midbass, leave the other side as is. Also try doing this with the sub turned off, once you get the midbass dialed in, turn the sub back on and see if it is what's causing the issue and maybe phase needs to be reversed on the sub.

keep_hope_alive
12-23-2013, 03:54 PM
certainly, phase on the sub can make it seem like midbass is non-existent.

time alignment can help also. without T/A differences in distance will cause phase interference.

stuffing will only help midbass and smooth response. hollow chambers are bad news bears.