SSpeedracer

iTrader: (8)

Need some guidance as I know next to nothing about any speaker manufacturer. I've got a convertible running an aftermarket HU to a 2 channnel (90W RMS/ch @ 4ohm) amplifier. Currently, it drives a pair of infiniti tweeters mounted near the top of each door and a pair of pioneer 3way 6.5" in the OEM location. Needless to say, the pioneers sound like poop and I never intended to drive them with 90W.

I want to replace the pioneers with a pair of woofers. Looking for low frequency response range at least to 55hz and willing to make sacrifices to keep price reasonable. The top is almost always down, so clarity ranks after dB.

What pair of 6.5" do you recommend?

Thanks!

ps
I intend to run the pioneers in the rear directly off the HU with a LP filter for rear fill.

unredeemed

iTrader: (2)

All of these need an amplifier to make good sound.

Real high end would start around here:

Focal Utopia Beryllium http://www.focal.tm.fr/

Seas Lotus Reference http://www.mobilesq.com/products/get_product.php?id=1

Morel Ovation http://www.morel.co.il/car.htm#

DLS Iridiums http://www.dls.se/english/index.htm

Rainbow speakers http://car.rainbow-audio.de/product...php?lan=2&pro=1

Real good SQ and great price.
CDT http://www.thezeb.com/p-CDT-Audio-CL...tem-101083.htm

Real good SQ, good SPL, and very good mid-bass
http://www.adireaudio.com/TextPages/...eFrameText.htm

unredeemed

iTrader: (2)

Oh and without properly prepped doors, you'll never get good sound out of any speakers you put in there.

Proper sound deadening is key to good sound.

Daley

What do you want to end up with ultimately (as far as a whole system goes), and how much do you want to spend? Unfortunately, bass in a 'vert is a difficult (not impossible) task. Depending on your goals, I'd consider leaving the pioneers where they are. Fill us in on some of your goals and we'll be glad to help.

SSpeedracer

iTrader: (8)

Unred- Thanks for quick response! I will look those over after I get off work.

SSpeedracer

iTrader: (8)

Unred- I put adhesive sound deadening material inside door as far as I could reach through the speaker hole. I tried making a speaker suround out of ABS, but ran into clearence issues with the window glass. I dont intend to do much more prep than mentioned.

Daley- I want to do the minimum amount of work/labor and spend less than $200 (if possible). The amp seems decent as it used to power a set of subs in the trunk. The problem is that subs weigh too much for my performance requiments and take up too much room.

The system has enough high end with the tweeters (my leg used to block the OEM location and make everything project form the passenger side). The pioneers are past their usable range with the amp and start to distort madly even at midrange, bass is a joke. But then I'm not surprised as the pioneers are only rated to ~65W max.

In the end I want to hear/feel some base even with the wind zipping through the cabin at 70 MPH. The higher freq of the tweeters and thier location already satisfy the top down requirement.

Richiec77

iTrader: (3)

Let me 1st say this: 6.5" speakers are not meant to be used as subs. So of course it sounds like ****. You are overstessing the cones and basically ripping the speaker slowly apart. This is why you need cross-overs. To pass the right part of the sound spectrum to the correct application speaker.

Unredeemed; You are correct only to a certain extent. If he was an audiophile or competing it would be a must to get the most out of his set-up. Since it's a convertable with the top down most of the time, it is not really even an issue.

I would focus on a set of components for the fronts, or add more speakers. High Power handling sounds like a key point due to the extra volume required to overcome all the wind noise. Convertables are notoriously difficult to have a good sounding system in. But as Daley said, it's not impossible.

What is your head unit? And What amp do you have?

For bass like you want, you are going to NEED a subwoofer.

Richiec77

iTrader: (3)

For around $200 dollars, I'll say your best bet is to spend it on a good set of front components or spend the money on 2 sets of 6 1/2" speakers. Put 1 set in the doors and 1 set in the sail panels.

SSpeedracer

iTrader: (8)

Bingo! I need quantity, not quality.

Pioneer DEH P77DH head unit and 400W pioneer GM-X572 amp (both 4V line).

I am looking for advice as to who makes good component 6.5 speakers that sound decent in camaro doors. Sampling speakers at a demo is very different compared to 70MPH with top down.

I was running a couple JL subs in the trunk. Problem is that sound was weak when top was down and overpowering when the top was up. Basically, it was never right and I had to constantly mess with the HU settings. I moved the subs to the back seats and it helped a little, but still had to mess with the settings each time the top went up or down. Not to mention, I had no place for passengers. So, I gave up on the subwoofer idea.

Your idea of putting good 6.5 in the sail panels is a good one. I want to drive the rear speakers with the HU. Does it make sense to get the same 6.5 front and back even though the front will be powered by a 90W amp? Or should I get "weaker" 6.5's for the rear?

Richiec77

iTrader: (3)

Bass in a convertable is probably the hardest thing for an installer to tackle. Usually The best Bass you get is when the Top is up. Once the Top is Down, there is no Cabin Gain to reinfornce the output form the Subs. Also it is usually muffled by the Top being in the area where it comes into the Cabin.

Putting 6 1/2" subs in the rear sails might not do much at all.

I see you are looking for more volume, So I'd say to put 2 sets of Coaxial, Or Component speakers in the Doors, and Sails. This should Satisfy Your Volume requirment for the Mid-bass through Treble.

For Bass, You are really in a hard spot due to the car being a Convertable. I don't have any feasable (cheap)ideas off the top of my head. Most ideas would cost some serioous cash due to a lot of Fabricating work. Hopefully someone has a decint idea to try.

Maybe (never tried it before) you can devise a piece to hold up the top so it doesn't totally seal off the truck when the top is down. Something like a short Table top. Maybe.


FYI. The Amp is 75x2 @ 4ohms, 100x2 @ 2ohms. So 75watts if you do Doors only 50 each if you do Doors and sails.

2MuchRiceMakesMeSick

While this is real important with home audio....remember that we are dealing with free air speakers that have outragous VAS's. Isolating the rear wave on a free air speaker is a bad idea and will sound like crap.



Using 6.5s as "subs" is generally a bad idea, for several reasons we wont get into. I think common sense applies heavily here.

If your looking for bass, why not do it right? How about a stealth box or a bazooka tube?

02Z28LS1

iTrader: (2)

to get some better sound out of some subs in the trunk of a convertible, you can mount a baffle board like 2 or 3 inches above the cones of the subs, so that the cabin pressure doesn't matter as much. it will still affect it some, but not as much as open air with no baffle board.

i read an article a few years ago about someone who had that done in their convertible, it was featured in Car Audio & Electronics magazine. if i can find the article, i'll scan it and post it up.

02Z28LS1

iTrader: (2)

i found the article and scanned it:

Right-Click and Save As

it's almost a MB, so dialup users may take a little while to download it.

SSpeedracer

iTrader: (8)

I thought about that also, but was a little worried about damaging the top. I think a forum member makes an enclosure that will accomplish this.


Thanks for posting that up. Very interesting.

I'm going to try this:
Replace the front coaxial with components and drive them from the amp.
Leave the existing coaxials in the sail panels and drive from the HU.
Possibly add a custom box on the shelf between the rear seat and trunk with ports into the cabin underneath the folded up softtop. I've already got 4 small subs that should fit nicely. I just need to pick up an amp and cable.

Question on the subs:
If I use four 4ohm subs, what is the ideal way to wire up? Is it best to wire two each to the left and right channel in parallel?

Thanks for all the info!

02Z28LS1

iTrader: (2)

that all depends on the amp that you use, and if the subs are single or dual voice coil speakers (i'm going to assume they are single VC). if you have just a regular 2-ch amp that is only stable to 2 ohms in stereo, then your best bet is to wire 2 pairs of subs in parallel, one pair on each stereo channel, so that it presents each channel with a 2 ohm load (two 4-ohm speakers in parallel = 2 ohms to the amp).

however, if you have a better amp that is stable to .5 ohms on each stereo channel (not likely), you could conceivably wire all 4 subs in parallel to equal 1 ohm, and bridge the amp, presenting .5 ohms to each channel.

and again, if you have a mono-block sub amp (1-channel sub amp) that is stable to 1 ohm, then just wire all 4 in parallel to achieve a 1 ohm load.

you never really want to wire two or more seperate subs in series, you always want to keep it parallel. the only time you want to use series wiring is if you have dual voice coil speakers where you are wiring the coils of the same sub in series, and the wiring can get fairly complicated with those, especially when you start getting larger numbers of dual VC speakers. see This Tutorial for an illustration of this fact. but you're better off with parallel wiring anyway, as long as your amp can handle the lower impedance, because you will get more power out of the amp when you use parallel.

two 4-ohm single VC subs in parallel = 2-ohm load
two 4-ohm single VC subs in series = 8-ohm load

a simple formula to keep in mind when using parallel:

a = speaker impedance
b = # of speakers
c = final impedance

a/b = c

so if you have five 4-ohm speakers in parallel, the final impedancewould be .8 ohms, because 4/5 = .8

and the reverse is true for series:

d = speaker impedance
e = # of speakers
f = final impedance

d * e = f

so if you have five 4-ohm speakers in series, the final impedance would be 20 ohms, because 5 * 4 = 20

one other handy thing to keep in mind is that when you bridge a two-channel amp in mono, it is essentially the same as having 1/2 the impedance....so if you have an amp that says it is 2-ohm stable in stereo, and you wire two 4-ohm speakers in parallel with the amp bridged mono, you're presenting a 1-ohm load to each channel, and will likely fry the amp (two 4-ohm speakers in parallel = 2 ohms, and also the amp being bridged cuts that impedance in half to each channel = 1 ohm = dead amp soon). however, you would be safe with a single 4-ohm speaker with the amp bridged mono, as it would present each channel with half that impedance, or 2 ohms. mono-block sub amps do not apply to this, as they are essentially 1/2 of a two-channel amp, so whatever impedance they are rated to handle, they can handle, no matter how you present the speaker load to it, because there is no other channel with which to bridge it.

Richiec77

iTrader: (3)

I remember that issue. I have done this before in a Geo Tracker back in the mid 93. Was a cool trick. I don't know if I was original or not at the time, but I figured it would work based on the Tech report I read that defined how turning subs backwards worked in trunks. It does.

That Idea would work well if he wanted to put the Subs were the back seats are, but he doesn't want to give up the space.

That Effect is called "Slot-Loading" it is used to reinforce the waves by trapping them into a common area and the pressure wave is finnally forced out with additional pressure. Same effect as Positive Displacemnt blowers (i.e. Roots style). A really good trick if you were to do a bit of custom work, but you said you want to keep the Passenger space, so I would work on the table idea

You can feel it work just by lifting on the top while it is in it's down position.

You said someone had mentioned this before or did it before on here? Would you happen to have a Link? I'm pretty curious to see the design.

Here is a good link for visualizing the Speaker set-up

http://www.sounddomain.com/shop/woof..._svc&x=150&y=7

There are also a couple of other ways to wire but these 2 are the easiest. I would recommend the 4ohm one. Most Amps are really happy with this load. You can get amps built to handle 1 ohm, but they are slightly more expensive. Really depends on the brand.


I would shoot for a Class D amp. They are great for Subs and have a lot of power in a smaller chasis and stay cooler for longer. They are Mostly Mono Amps so they are usually set to run there maximum power into 1 ch anywhere from 1ohm to 4 ohms.

Class AB amps usually are Multi-channel amps. Very few Clas AB amps are Mono.

Look for a new Post in the FAQ on The differences between Class AB and Class D and the benifits of each

02Z28LS1

iTrader: (2)

no, i wasn't talking about someone on here, i was talking about that article that i posted....i didn't mean they'd done it in an F-bod convertible. all i remembered when i posted that is that the vehicle was a convertible and they used that design to keep the bass response when the top was down. i just didn't realize that he had actually mounted the enclosure in the passenger compartment, i thought that he'd had it in the trunk. but hey, i'd say that i still have a pretty damn good memory, considering that article was printed in 1996.....

and that design is a little different than slot loading.....rather than "pressurizing" the bass wave, it reflects (and couples) the wavelength before it has a chance to travel it's full length.

just for the benefit of anyone who doesn't understand what i'm talking about, i'll explain it the best i can......

there's a reason soundwaves are called soundwaves....it's because they literally travel in waves. a soundwave has a set length from peak to peak (or valley to valley), depending on the frequency of the wave. for instance, take a look at the image below:



the lower the frequency, the longer the wave is from peak to peak. the problem is, with lower frequencies, if it is allowed to travel without being reflected, its volume decreases greatly the farther it travels. so in a convertible with the top down, you tend to lose quite a bit of volume unless you have something in front of it to reflect (and therefore, couple) the sound wave. generally, the more times it is reflected before the sound wave is allowed to travel past its wave length, the louder it will be perceived. obviously, there are a lot of other factors, but this is just a general description of the way it works.

the main difference between this method and slot-loading is that slot-loading not only couples the wave, but pressurizes it also. this method only couples it. very subtle difference, but it is a difference nonetheless.

Richiec77

iTrader: (3)

No. SSpeedracer said he had seen it somewhere on here.

Ok I took a better look at the pic. That is just a reinforcement plate. It is just allowing coupling like you said since it was just open all the way around.

And you are correct. This is way simplized version of it all.

But that's an idea you might be ablt to try out. Making a loading slot to direct the energy out under the top into the listening area. Shouldn't be difficult to construct if you already have a box in the truck.It's almost the same effect as a Square port, and is really similar in design.

SSpeedracer

iTrader: (8)

http://members.aol.com/jbslim/Johnny...e/JohnnyB2.htm

Richiec77

iTrader: (3)

Thats exactly what I was thinking of. Might just be the best solution for a convertable. Looks like the ports fire into the cabin area and the subs still fire rearward.

Top down, still have impact from the ports

Top up, bass is reinforced to make it even louder.

I'd say to go for this idea.