Audio help, Ideas

['00vegas-solara]

Ok, I want to get serious about my Solara’s audio system. Here’s what I have so far:
I’ve replaced my speakers with Polk Audios DB6500 in the front and DB690 for the rears. I also have a single 10” VISONIK V110D4 Subwoofer in the trunk. I have a Power Acoustik OV4-800 driving all of the speakers. The rear channel of the amp is in Tri-mode. Here’s my question, my music is not as clear as I think it should be. At higher volumes I begin to here what I think is distortion. Is my amp cheap? Are my speakers? I have a SoundBlaster Audigy 2 ZS soundcard installed in a Laptop as my head unit. I don’t think that is the problem. I’ve always read to look for RMS power, THD % and Signal to Noise ratio when choosing an amp, so I thought this amp was decent. Sensitivity is what I thought to look for when choosing speakers. I’ve noticed JL audio is a common brand on this board, what makes them better then the others. I’ve compared their specs to the Power Acoustik and they didn’t seem that much different. I also see that everyone has their sub facing away from the rear seat. What’s with that? Any ideas or info is appreciated.

[theprodigy79]

A few comments right off hand:

Your Polks are good... they are very solid speakers and should do what you need 'em to do...

Your sub is alright... Put it in a decent enclosure, power it right and it shouldn't be a problem... For this particular sub I'd recommend a .75 Cu Ft sealed box if you want the best possible quality and pretty decent output. As far as directional placement of the sub, try it both ways (firing both toward and away from the seat) and see what gives you the most output.. I'm sure you'll find that firing backwards gives more output. This has to do with the way bass wavelengths travel and reflect throughout your car... Aiming your subs forward generally causes more wave cancellation (this occurs when sound waves are completely out of phase)... you will actually notice that you have greater bass output when your trunk lid is open due to the loss of some of these cancelling waves. The BEST position for a subwoofer is actually ALL THE WAY back against the rear of your trunk, facing the rear... however this is not usually practical, as it wastes a whole lot of space... so the best alternative is usually to place the sub against the seat firing to the rear.

Watch out for running the sub on the same channels as your rears... I'm not sure what "tri-mode" is, but usually this isn't a very good idea...

I apologize for the bluntness, but the Power Acoustik amp is garbage. As far as the GOTHIC vs a JL or Alpine amp... You're literally comparing apples (rotten ones) to oranges... By rated specs alone, the JL and Alpine amps are rated at between 102-109 db S/N ratio, whereas the Power Acoustik is rated at 97db... By actual reality, an Alpine or JL amp rated at 45-75W per channel will have no trouble keeping up with your current amp as far as pure output, and the output quality will blow it away. Watch out for amps claiming 800W that retail for less than $100...

Now, a few questions:

What kind of connection are you running between your laptop sound card and your amplifier?

What is the voltage of the output?

Is the output fixed or variable?
-If it's fixed, what are you using to monitor / adjust volume?
-If it's variable / software controlled, it's a common problem to have noise or distortion at higher volumes... check for driver conflicts... also make sure there are no hardware conflicts (ie if your laptop has an onboard soundcard)...

I'll be thinking more about this... but the answers to the above will definitely help.

-James

[lilmike2069]

just ditch all of that and upgrade to the complete Alpine F1 status system.... Can't go wrong with that... in fact, i think your car would make it to every single car audio magazine printed

[dgdtech1072]

another suggestion for your sub would be to port it through the rear deck. although this would require you to cut a hole in the rear deck and then cover it with some type of screen (for looks) it would give you better bass quality since instead of being closed up in your trunk the sound waves can now bounce off the back window. as for your sound quality for mids and highs you should think about installing some crossovers. this way the low frequncies will only go to the speakers intended for low tones and vise versa for your high frequncies. althoug wiring in the crossovers will take some time, your sound quality will be better. if your amp says it has
a built in crossover they usally dont work because they just either cut the low tones out or the high tones, no in between.

[theprodigy79]

just ditch all of that and upgrade to the complete Alpine F1 status system.... Can't go wrong with that... in fact, i think your car would make it to every single car audio magazine printed

Yeah... an upgrade to complete F#1 status is an awefully realistic jump from two sets of $150 speakers and a $50 sub running on an $80 amp... Even if it's a $5000 laptop it still doesn't cover half the cost difference...

He has a good concept that I think can work very well if he's able to just pinpoint the source of the problem... It's a tried and true methodology that can be really cool when working properly, however it's a true pain in the ass to setup properly and there is a lot to go wrong with it...

dgdtech1072 does bring up another very valid point... Crossing over your speakers properly can make an immense difference as well... Another question: How do you have your rear speakers and sub crossed over if they are sharing the same channels? As I said, I'm not familiar with this tri-mode feature and I'm definitely a skeptic of it...

[cam2Xrunner]

IMO

Bridge the 4 channel amp you have right now to power your front speakers only, ditch the rear speakers altogether(not for something else, just no rear speakers)

Sell off the Visonik sub(sorry, no offense but Visonik is crap. It's swapmeet equipment)

If you want suggestions for another sub and amp to look at, post a budget(If you want to go this route)

If the Power Akoustik amp you have works fine with no added noises and no turn off pops/clicks, I'd say use it. You probably won't hear a difference between this amp an another of the same power.

[Assyrian]

You know, I'd go with what James recommended. He's given me some great advice on my setup so far.

['00vegas-solara]

Thanks for the info so far. Don’t worry about being blunt. I wouldn’t have posted if I didn’t need help. I have read a lot of your postings Prodigy so I'm glad to see some responses from you as you seem very knowledgeable about car audio. Here’s a picture of the tri-mode setup I have. I have installed the inductor and capacitors on the speakers at the 150Hz frequency.


As alot of people are stating I too will be getting a Tax return so I'm loking to upgrade my audio system. I think from what I've heard so far I'm going to replace my amp with 2 amps (1 for front and rears, and 1 for dedicated sub) and a new subwoofer.

Here are the Specs of the soundcard:
* High Signal-to-Noise Ratio (SNR) exceeding 104 dB using high linearity, low distortion 24-bit converters with resolutions of up to 192 kHz
* Playback: 24-bit Digital-to-Analog conversion of digital sources at 96 kHz to analog 7.1 speaker output, 192kHz for Stereo DVD-A
* Recording: 24-bit Analog-to-Digital conversion of stereo analog inputs at 96 kHz sample rate
* Supports Sony/Philips Digital Interface (SPDIF) format of up to 24-bit/96 kHz quality at selectable sampling rate of 44.1, 48 or 96 kHz

Audio Performance
Signal-to-noise Ratio (AES17, A-Weighted, 20kHz bandwidth) = 104dB (2V Rated Output)
Total Harmonic Distortion + Noise @ 1kHz (AES17) = 0.006% (2V Rated Output)
Frequency Response (+/-3dB, 24-bit/96kHz input) = <10Hz to 46kHz (2V Rated Output)

Does that mean anything to anyone? I dont think the laptop is the problem but if it is I will have to live with it as I'm not going to remove it. One more question. I need some recommendations for 2 amps and a new sub for $500?
Thanks.

[theprodigy79]

Those specs mean plenty, thank you.

Looking at the setup, I believe that moving to a dual amp setup (or a single 5 channel amp) will solve the majority of your problems, and give you the best overall results... Power the mains separate from the sub and remove the bass blockers...

Your laptop should be fine with that sound card. Do you know what kind of connections you are using on your laptop (are you running it out of a mini-jack to a Y RCA converter, or does your soundcard have RCA jacks directly on it)? Make sure you have good quality connections using good quality cables.

For now, I ain't worried about your sub... it ain't the best, but you can get decent response out of it if you put it in a decent box... The reasoning for the box I recommended for you is that sealed boxes are usually cleaner sounding than other types of boxes, while still maintaining good power handeling and output. The size I chose is toward the larger size of the sub recommendations, however this allows for more roll-off and low frequency extension. Smaller boxes allow for quicker response, however for that sub you would probably be better off with the roll over punch. Also, if you chose to upgrade your sub, a .75 CuFt box is still usable by many higher quality subs (whereas smaller boxes tend to limit what you can use). Replacing the sub itself should be low priority, if you have $500 to blow, spend it on the amp(s).

Cam2xrunner has a reasonable idea if you want to improve your current setup while waiting for the tax return (or as long as you want if you're happy with it)... If you're willing to do without rear speakers you can stick with a single 4 channel amp, running your fronts on ch 1/2 and your sub bridged in mono on the 3/4th. This would eliminate the overlapping of your rears on the same channels as the sub, which I still view as the biggest problem in the setup (and the largest potential for the noise besides potential issues with the output from the laptop to the amp). Since this would also free up the amp cross-overs you can independantly adjust them for the mains and for the sub. Bass blockers (micro-caps / inductors) aren't very good solutions, and should be removed.

Gotta get back to work... more later!

['00vegas-solara]

For ease of installation I think I’m leaning towards a 5-CH amp. I already have my 4awg power wire ran and all the speaker wire ran under the driver’s side seat. The 2 I’ve been looking at are the JL e6450 with the 6th CH bridged or the Crossfire vr705d. I’m open to any other 5-CH amp recommendations.

[indiglosolara]

The JL Audio 500/5 will do good with your system.
You can set-up your amp to designate 4 channels to your mids. Front and Rear. And one channel for your Sub output.

I have a friend running the 500/5 amp powering front and rear boston acoustics components and 2 Jl audio W3v2 subs.

You can probably get the JL 500/5 amp for about $350 to $400 online. Also dump the sub you have. Go with a nice 10" JL audio W6 or even W3. You will get a nice clean sound with that with the front and rear speakers you have.

Also DO NOT GO with the e6450 amp from JL audio. The amp is good but you will have more power with the 500/5. I've had the e series Jl audio amps and i feel as if they are over rated with the power specs. Stick to the Slash series and you wont be disappointed.

Alpine also has good amp and subs. Thats going to be my next set-up. I'm not sure if they have a 5 channel amp or not since im still doing a little research on Alpine's Audio.. But im sure we have some alpine guru's here that can help.

['00vegas-solara]

You know I thought about the JL 500/5 but what’s with the 25W rear CH. Is that really the rated power. I would think I would need the front and rears balanced.

[skadoo323]

hey there. just wanted to say i admire your carputer work. i am trying to put one in my solara as well, but i dont want to do anything permanent, which kinda makes my mounting options harder. for now i will go through the stock head unit as i already have an aux input for my ipod, but it has an extra aux in. i'm thinking of some ideas, so i guess we shall see what happens. but yeah anyways, awesome job! good luck with your audio upgrade as well. also as others have said go with some name brand things that will work well. when i first got into car audio rage when i was a teen with my slightly riced out civic i went cheap on some audio things and it does make a difference.

[theprodigy79]

You know I thought about the JL 500/5 but what’s with the 25W rear CH. Is that really the rated power. I would think I would need the front and rears balanced.

As Indigo stated, DO NOT go for the "e" series JL amps... they are JLs entry level amps that are all hype and no kick... The "/" (or "slash") series is their original, and best line-up.

I'd recommend the 500/5 as well... It's an awesome amp, and one that I'm actually considering for my future installation in my girlfriend's car (if that says anything). The 25Wx2 rear output is accurate, however the rear speakers are intended mostly for rear fill, and the front give the sound staging... this is the reasoning behind the tapered power output of this amp. Also keep in mind that these are 25 solid, REAL watts that will power your rear speakers just fine.

As far as the sub goes... If you have the $$ left over after purchasing the amp, the best matches for that amp would be a JL 12W3v.2 or an Alpine SWS-1242D. The W6v.2 series take more power to be run truly efficiently, and in my opinion wouldn't be the most suitable match (although you can run them)...

['00vegas-solara]

Hey Prodigy what do you think of the Crossfire vr705d? Any good?