scroggy1984

Hey guys,

I am new to posting to the forum but I have been reading for a while. I installed a Sony Xplod 1200W amp with 2 JL audio 12" subs along with a LOC and no matter what I try, it sounds like utter garbage. The amp has a low-pass filter, which, when it's turned on, cuts the bass down to a tenth of the level (even with the gain turned all the way up). When the LPF is turned off, I definitely get a lot more punch but it's almost like it's using the subs as regular speakers and it sends more than just the bass through the subs. It doesn't matter whether the subs are point towards the back, front, top, or bottom, it sounds like garbage no matter what.

Is there anything I can do? The LOC is installed through the existing sub wiring and I have the RCA's going directly to the amp. I have seen some posts about getting better quality using the speaker inputs (although i don't have the pigtail to connect them, but I am willing to buy one if it will give me better output) and some posts about some sort of SQ something or other, but I don't know what that is.

Any help at all would be greatly appreciated. Thanks!

pohljm

should not be any problem feeding amp the way you described. there will only be sub signal from that output, not a full range signal. how are the two subs wired? i would bet thats where you have issues.

scroggy1984

The amp has a left output and a right output and I have each speaker wired to the appropriate input. I've tried swapping the leads to make the invert the coil and that helped a little bit. Would it help even more to bridge them?

Gregerst

iTrader: (1)

You may not even need to use the loc. Just run the sub wires directly to the high level (speaker) inputs of the amp. keep in mind also that the sub signal is already crossed over at 80Hz i think.

stevemk07

I have a Sony amp and not a fan of the built-in filters... degrades sound quality so I dont use em. Yes the sub signal is already crossed at 80hz... 12db/octave I would guess so just turn off the amp filters. Turning them on and off will affect the phase of the signal so you may need to reverse polarity of the subs. If you really want to have a good look at things get an app or program that provides sine wave test signals and then play an 80hz signal... turn sub off in the head unit controls and then turn sub control to -6 to see if the 80hz signal becomes louder or quieter... that will tell you if it is relatively in phase or not (it should get louder). You can repeat those steps for 70, 60, 50 hz and even up to120 hz. Best if they all play in phase. Easiest to accomplish without the amps filters on. Hope this helps some.

Another thing to consider is what you might be missing is midbass.... add dynamat or something similar around the door speakers which should help in that regard quite a bit. The better you deaden the install area the better your speakers are going to sound. Some people seal off the whole door too. I use the door panelas the seal and make sure it is sealed by adding open cell foam weather stripping around the speaker snd on the inside of the panel around the grill. ($3 at the hardware store)
Also... IMO the tweeters are too hot ...add 5watt 2 ohm resister in series to the negative leads to tame them a bit. Maybe even 4 ohm but I was satisfied with 2.

I should also add that I doubt the infinite baffle people around here have to deal with phase issues with their subs as much as us with boxes in the trunk. For me I had to add two external ports and then play with the port directions and lengths to get it all in order. Also if you tune your boxes to the drivers Fs you maximize the transient response. If sealed.... I like corner placement facing the cabin but it could be completely different for your setup.

scroggy1984

If I change it from the LOC to the high-input connector on the amp, will that make a difference in the sound or is that just another way of getting the same signal to the amp? If it will get me a different result, i'll definitely buy the connector and switch it to the high-input.

Steve - I hate to sound like a noob but can you explain exactly what midbass is? Obviously, your tweeters are high's, sub's are low's. Is it exactly what it sounds like...midbass is the in-between of the tweeters and subs?

I have put sound systems in my previous cars but I've always had the aftermarket radio set-up and have never had to get this involved, so honestly, I have no idea what i'm doing aside from turning the dials and seeing what combination works best.

Thanks guys!

Gregerst

iTrader: (1)

What you'd be doing is eliminating any possibility that the LOC is part of the problem and to a lesser degree the amps low level inputs. Troubleshooting is sometimes a process of elimination.

I hate cars

Built in filters absolutely do not degrade sound quality. What exactly do you use to lowpass your sub? A filter.
Where did you get that number from?
This completely depends on the slope and if phase is compensated for. Phase is not just 0 or 180. Some are already compensated so you have to do nothing. What would you do if the lowpass is on a 24db slope?

How will 120hz work when the stock filter is 80hz/12db?
Sealing off the door is the ONLY way to do it. You're trying to prevent the backwave from meeting the front wave. Stock TL speakers will never have even decent midbass and will never be a vibration issue. They have been Klippel tested and have about 1mm of linear excursion, they CAN'T have good midbass or cause door vibrations, at least not below 100hz.

I've never in my life heard anyone think the stock tweeters are too "hot". You're probably mistaking the cone breakup of the non lowpassed mids.

Why would IB people have less phase issues to deal with? It's a large sealed box.

Changing the port length changes the tuning of the box. While you think you were dealing with phase you were dealing with enclosure tuning. Fs is where the most distortion is. Mine have an Fs of 20hz. So you're saying I should have a tuning frequency of 20 hz in a ported box? The OP said he has 12" JL subs, no model or anything so the Fs could be anywhere but in general you don't tune to the Fs unless it just happens by chance to be the tuning frequency. In reality it's a good idea to stay above Fs if possible but not super important with a sub.

Hope this helps.
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For the OP, I'm assuming the lowpass on the amp is adjustable. Set it between 60-80hz. It sounds like you have the low pass frequency set very low and that's why you're losing all of your volume when the filter is on.

You have any bass boost functions disabled on the amp, right? Does it have a subsonic filter or highpass filter?

I hate cars

I agree to get rid of the LOC temporarily to eliminate it as a possibility.

What amp are you using and how do you have the controls set?

scroggy1984

The amp is a "Sony Xplod 1200 watt 2/1 channel power amp", model XM-2200GTX. The dials on it are "level", "low boost", and "filter". The LPF on/off switch is right below the "filter" dial. Neither of the dials are "set" as I have been playing with them, trying to get the combination right. Right now, level is at about 3/4 of the way up, low boost is all the way down, and filter is just a hair above 60. The numbers on the filter dial go jump from 60 to 110 so I just eyeballed what I think would be about 80 since the other guys said the factory amp is set at about that range.

I think the guy that had the car before me had the same issue because there is an LOC there and I also found speaker wires in-line with the rear deck speakers, so I think he might have started with the LOC as well and moved to the high level inputs. Or, I could be wrong and he went the other way, I don't know for sure. I'll be going to Best Buy tomorrow to see if they have the high-level input connector, so i'll let you know how that goes.

I definitely don't have the money to invest in a 3sixty or upgrading the rest of the speakers, I just wanted a little more punch in the bass.

Has anyone had luck replacing the radio with an aftermarket radio but keeping the stock Navi in working order? That might be an option but it would be down the road.

I hate cars

Sometimes those dials can be off. To make sure the filter setting isn't the problem, turn it all the way to 300hz. The subs should sound the same with or without the filter. If they do, it's just a simple matter of adjusting the frequency until you like the sound with the filter on.

stevemk07

My guess is that the high level inputs on your amp are good if it functions properly. I would definitely see about trying that instead of the LOC if you have checked your sub connections already.

As for midbass.. yeah its higher than the sub bass and lower than the midrange... about 60 up to 300 (most people will have a different definition but in general above the sub bass frequencies and before the vocal or mid range .. vocals tend to exist between 300hz. and 3k so they call that the midrange... weak midbass makes the whole thing sound weak even if you have plenty sub bass. Guitars will sound thin and drums just wont have that full impact they should have. Of course if your missing/lacking a chunk of response in any region it will degrade the sound but for most looking for a pleasant warm sound you need to have decent midbass.

As stated already just improve installation of door speakers and this will fix that problem. Check the rubber surrounds also to make sure they are glued on properly with no leaks. I used crazy glue to fix mine before changing them.

Do not listen to I Hate Cars. He will tell you to get the most expensive and elaborate equipment available because that is all it knows how to do. That is just a waste of money if you never learn the value of proper instsllation methods.

IHC, the front wave is sealed off from the back wave due to the fitment of the panel. Think about it before disregarding simply because I said it. I have foam on both the outside of the speaker mounting ring and the inside of the plastic stuff around the grill. That foam is compressed when the panel fits back on the door creating a barrier betwwen the the front of the speaker/cabin and everything else behind the door panel. Everything else in the vacinity of the speaker is deadened.... not 1" x 1" but generous amounts and multiple layers closest to the driver.

Last suggestion: He can even put deadener on the speaker baskets (spokes?) to yield improvements in tonality from the stock drivers.

For the record, I am stating my findings through my own experimentation and despite what the norm is or what others would recommend I stand by my recommendations because I know what I am doing.

Side note: IHC, you should do some reading about what phase is before making obviously uninformed comments.

Done with this site again for a while as IHC has found that I am back trying to save others money and time again.

Aside from his expertise (hardly as he does not understand phase hence sound) on infinite baffle I would not listen to anything I Hate Cars has to say about sound systems or anything else under the sun.

I hate cars

Stevie, at it again. You don't always have to bring expensive equipment into every conversation. I told him to check the amp settings. It sounds pretty cheap to me.

I have some nice gear (as you like to point out, thanks) that's run fully active with the best processor on the market for tuning and some really nice RTA gear to get the most out of it. You seem infactuated with my gear for some reason. You seem to think you're the only one that has stuck some rubber on things or used an RTA. I've stripped my car to a metal shell to install damper and noise blocker. The whole cabin. The upper console, under the head liner. The seat backs. The trunk. All doors. The deck. Foam to seal up every crack and crevice under the deck. Luxury liner pro sound blocker all over the car, not just damper. My doors have 9" midbass that I fit behind the stock unmodded door panel not just some run of the mill 6.5". My amps are under the seats with 1200w on tap for the front stage which is 700 more than my subs so that my system can accurately reproduce the dynamics in music giving better SQ. My subs take up almost zero room and require 250w each to hit full excursion which incidentally will flex the windshield to scary levels yet blend seamlessly with the midbass for sq use. They're more efficient, have a flatter response, dig deeper and sound better than what you have. They're also $150 each, not exactly expensive. I built and sealed my sub baffle, i didnt just slap a box in the trunk. It plays nearly flat from 20hz to over 400hz or whatever lowpass I use. My midrange are molded into the kicks on axis and take up no floor space and are hidden from sight and look stock if you can even find them. My tweeters have been machined down to 4" to fit on the dash ON AXIS with myself and integrated into the pillars to look stock. They are not firing into the windshield, the reflections kill the stage when they fire that way. Sound absorption material has been applied to the under dash area. The center channel has a 6.5" midrange for future use. I have some of the best tuning equipment out there and I've put over 100 hours into the tune and a top notch installation that began with the car stripped if the entire interior.

So tell me again what exactly your install with a piece of rubber stuck to the door has on mine

I suggest no one put damper on the basket of their speakers lol. How cheap does your stuff have to be to have basket resonance. Note, resonance is not tonality.

A piece of rubber on a metal panel will never make a difference when you have 1mm xmax to play with lol. 1mm! It's mathematically impossible to have appreciable output below 100hz. I'll model the stock mids to prove my point tomorrow.

Human voices start from as low as 80hz and some components extend past 10khz.

I see you disagree with me about phase but you have not made a counter argument. Instead if saying I'm wrong why don't you try to educate us.

stevemk07

Ok short post before I fall alseep...

I skipped through your install. I am sure it sounds good by now... after what... 4 years of trying to make aftermarket speakers including boxes full of various dyn audio drivers sound as good as stock? Come on! You're.... well I won't go there until the end.

As for midbass from the stock speakers...there is plenty to be had. After all of my improvements the RTA showed a peak frequencu response of 48hz without a sub.... and bass set to +1. As you should also know, they stay fairly linear up until you reach the max power of your amp when crossed at 80hz. I have a good ear for music and tone and had no problems with their xmax except when playing "all right now" by free of all songs and cranking the volume past 35. Xmax is not everything. Maximizing the output of the driver is more important. That is done by ensuring rigidity of the install area, minimizing or in my case nearly eliminating cancellations from the back wave both of which maximize the sound wave energy emitted from the driver. There are too many variables to single out xmax. No I am not going to teach you about them all. If you want to learn something from me learn to not hate people and inanimate objects. Hate death and violence (including malisciousness and slandering, or in this case libel... yeah just google it all)

I hate cars

48hz from the stock mids? You need to read the instructions on how to use an RTA. They don't go that low period. There's 1mm of travel. When I get home I'll prove it to you. The stock mids do little to nothing below 100hz. I've but 75w of aftermarket power to them after all and they had to be highpassed at 120hz to not bottom out. It blows my mind that anyone can possible think the stock mids go down to 40hz. Unbelievable.

You're way off in left field. Don't give me your liberal nonsense. This is about car audio.

I went through several speakers before I settled on the right ones. Got a problem with that? Some people have standards.

stevemk07

Yes 48 hz with 80 hz high pass.. I know.... my work is truly amazing sometimes.

I hate cars

The issue here is you don't have that internal system of self checks and balances known as common sense. If you understand how a speaker works and understand you have only 1mm or 2mm peak to peak to work with you would understand the stock mids are not capable of producing an audible 48hz tone. Somewhere along the way a light bulb should have gone off and you should have realized if you're getting a 48hz "peak" something is flawed in your testing. People run 9s and 10s in the doors to be able to reproduce the 40hz range decently. 40hz gets my 9s moving about 1" with it cranked up and I have more than double the cone area and 13 times the excursion of the stock speakers.

You need to go back and try to find out where you went wrong with the RTA. Until then, none of your measurements are valid. You should be interested in accuracy, not trying to prove the stock speakers can produce a 48hz tone.

And again, how do you get a 48hz tone when the speakers are cut off at 80hz by your own admission.

pohljm

I kinda missed this.......for like a minute!

350

iTrader: (4)

Can you give a little more details on the equipment? Did the amp sound good to you in the past? 1200 watts RMS or peak? I'm not an equipment snob but anything that said Xplod on it would not get my money. Are the subs W0's or W7's? Just asking to see if maybe the equipment is the issue. Do you have any friends with sub amps that you could maybe swap out for testing?

I hate cars

I'm sure you skipped through my install because it puts in perspective just how little you've done with your patch of rubber on the basket. You might realize just how basic the things you're doing are and that I've already incorporated this into my intstall. These "ground breaking" things you think you're doing have been in use by most of us for years. What I'm trying to say is know your place.

The underlying theme with your posts in regards to my "expensive" (that's relative, it's not expensive to me) speakers is jealousy. That's exactly how you come across, bringing up the price of my stuff in every post.

You assume they "sound as good as stock". If you stopped the assumptions (well lies) and stuck to the facts you would have nothing to say. There's nothing wrong with buying bargain basement swap meet junk as you have but I could much more easily point out the flaws in your equipment which I have actually heard with my own ears. What can you possibly say about Dynaudio other than the price? You haven't heard them.
48hz is inaudible from a stock 6.5" as anyone on here will attest to. Improve your testing techniques.

Uh, they have 1mm of linear xmax. That's how linear they are, out to 1mm. Your feelings do not matter here, this is not subjective, it is objective and a look at the klippel will show they are linear to 1mm which will be hit at very low volume at 80hz.
Who says you have a good ear for music? Yourself? Okaaay. If you have cranked them, you have had trouble with their xmax as I will prove in winISD when I get home. Your ears just aren't good enough to hear it.
How do you think a driver makes sound? How do you think you increase output? I'll answer this one for you, excursion and you move the cone farther for more output and farther the lower in frequency you go for the same output. Xmax is everything when you're talking about a speaker with 1mm of it. Please do some research so I don't have to continuously correct all of this nonsense.
Again, do you really think a driver with 1mm of linear excursion is going to cause any vibrations below 120hz?

You talk about backwave and cancellations but you don't have the doors sealed?!?! How have you measured these "cancellations" to show that you have eliminated them?
You don't want to go there because you have no idea what you're talking about. Instead of adding feelings to this discussion, try some facts so we can have a discussion. Please show me with facts how I'm wrong. I ask questions with each post and you dance around them and ignore them. These are questions that would prove one of us right if you were able to answer them.

Tell me these other variables besides xmax. You can't. You dance around these discussions with lies and absolutely no facts and turn around and act as if I know nothing. Then you get mad when I continuously prove you wrong and notify moderators because you can't prove me wrong and if that doesn't work you make underhanded personal remarks just barely keeping them under the moderator radar.

Worst of all you mislead noobs. I feel bad for the guy who tries to run his stock midbass down to 48hz and pops them.

stevemk07

Im sorry. Could you repeat that?

I hate cars

I knew when it came to facts and calling you on your lies you would fold. I'm still going to show proof that you're lying about the stock mids being able to produce yet along "peak" at 48hz. You don't get off that easy.

pohljm

That is pretty much the response I expected. Perhaps he will disappear from here again. Its been an enjoyable few months or so not having to read the nonsense. I feel like I should have never mentioned tuning with protectants! then poof it was like Jumanji and i called his name three times

Oh yeah and the only time my OEM mids made a 48hz tone was the thud they made hittin the concrete dropping them during removal

niebur3

FWIW, I hate cars is spot on with everything he is saying and staying pretty reasonable considering the utter non-sense he is dealing with.

I hate cars

Thanks Jerry. I've got to get some kicks out to you quickly.

stevemk07

Lol.... still waiting for the "proof"

niebur3

I wouldn't feed the troll anymore, Matt.

Factory door speaker peaking at 48Hz It was probably the factory sub making that note, as I doubt it can even go much below that...lol.

stevemk07

Is this the source of all the erroneous information coming from the dumbasses?

Gregerst

iTrader: (1)

Great, now that sideshow bob has left maybe we can get back to helping the OP. Hopefully he will look at bypassing or replacing that LOC and going straight to the amp to see what kind of results he gets.

Gregerst

iTrader: (1)

Oops I spoke to soon.

I hate cars

It's soooo hard. If you want to see something funny, search his posts at DIYMA. He's a self proclaimed "purist". He talks about my lack of tuning but he uses no eq and practically no filters except on the tweeters. He has his subs and mids running full range! Lol. I bet that sounds good. He has a peak at 300hz but refuses to "color" the sound with eq. I *think* just maybe the car is coloring the sound lol.

pohljm

actually the ball is in your court on the proof situation. grand statements coming from you with no proof whatsoever. please educate us we want to learn.

niebur3

Resorting to name calling now??? I believe I should report this post out of respect to the other members of this forum.

Steven Bell

iTrader: (2)

WARNING:


Steve, look-you're new here. We're glad you're on AcuraZine.

But when things get personal and resort to name-calling, that's where I step in......


You and I had a conversation via PM yesterday. I asked you to not resort to name-calling or make things personal.

This is your warning. One more like this above and you'll get a vacation from AcuraZine.


Obviously, this goes for everyone.

--No name calling
--Keep the conversation "gentlemanly"
--You can argue a point without resorting to things getting personal.



Enough said.....

scroggy1984

Ok, so...it turns out that a couple of the ports (big thick paper towel tube looking things) got lost and that was causing most of the issue. I replaced the enclosure and it sounds much better.

Now, when I turned on the low-pass filter on the amp with the new enclosure (sealed), I get absolutely no sound from the subs. They are moving...but there's no sound. Is it possible that the factory sub is already on a "low-pass filter" and they are cancelling each other out, producing no sound? It still sounds like i'm getting some vocals through the subs so I was thinking that I would turn the LPF on and it would cancel that frequency out (unless the singer has a really deep voice, obviously).

What do you think?

I hate cars

I would check polarity. If they're wired wrong they will cancel each other out. I was amazed at how perfectly they canceled each other out. It was as if they were off but they were moving a lot at times.