fredmr39

Still assuming mid-range rather than mid-bass:

He would still be using the factory amp. If he want midrange sounds - the best way to get that with the factory amp at that location IMO is to pull wires from the HATCH midrange components he has there (Firebirds have a separate tweeter and midrange component in the back unlike the Camaro....so the signal would divided already, and a 4 ohm load is what the factory mid component in the back is so that would be fine too)....of course he would lose the hatch speakers, but it would bring the midrange closer and he would have higher quality speakers there so it would/should make a difference.

B T

>>>>
He would still be using the factory amp.
>>>>
The rear hatch speakers get amplification from another amp or is it the same one for the sails?

Do the sail panel speakers get the same watts as the back thunder pumpers.

fredmr39

The tweeters in the Firebird (front and hatch) are powered by the HU, while the midbass portion of those components as well as the sail "subs" are powered by the Monsoon amp.

No...it is roughly guessed that the sail "subs" get 300 watts peak per pair (150 watts peak each).......the rest is probably something like 125-150 for the doors and 50-75 for the hatch area......who knows, but the "subs" in the rear sails get the most power.

Also, doors are definied as the front most speakers, hatch speakers as the rear most (in the hatch area behind the rearmost seat), and sail panel speakers being those aligned WITH the rear seats (the "subs", or I guess as you say...more commonly known as the "thunder pumpers").

B T

>>>


......who knows, but the "subs" in the rear sails get the most power.

>>>>
very true,


(the "subs", or I guess as you say...more commonly known as the "thunder pumpers").[/QUOTE]

Naw, I totally meant the rear hatch area. I just meant there is no justice there for performance, with any speaker at any time with OEM VOLUME for any reason other than adding an amp to the mix.


EDIT: for mid base replacement in the sails with oem volume/watts


Edit II: with a nice usage of MID range.

Gordon0652

iTrader: (4)

So basically you would need to get a new Amp, and maybe rewire the stereo(speaker wire)? (inline filter)

WhiteBird00

iTrader: (4)

No, you don't need a new amp. If you want to put midrange speakers (or even a coax full range) in the sail panel area next to the seats you can do it and still use the factory amp. However, you will have to disconnect the hatch speakers and use their wiring to connect your new speakers. That's because the factory sail panel speakers get only a low (bass) signal that would not drive your midrange or coax. This is not really "rewiring" - it's quite simple to disconnect the hatch speaker wires and just pull them forward to the sail panels. You might have to add a little of your own wire to avoid having to untape the harness but that's about all the modification necessary.

If you want to put replacement speakers in the hatch area - give your head a shake. There's no reason to put anything new back there because it's just fill sound anyway.

TA guy

iTrader: (1)

When I said that output between a simgle 4 ohm vs an 8 ohm driver "all else equal" driven by the same amp, I was referring to driver design. What you are talking about is wiring configurations. BIG difference. My arguement in driver design is that the length of wire in the magnetic gap for a 8ohm driver is twice the length in a 4ohm driver. Double the impedance means double the length of wire. If you revisit the equation I gave you earlier, you can see that the efficiency increases as the impedance rises. This is oversimplified but thats the gist of it.

What you are talking about it using the same woofers in different configurations, and in that case more power is always going to be louder. Until something breaks anyway.

As to your various configurations, I don't know what your actual power was, so just picked a round number for illustrative purposes.
1000w@1ohm reference level
500w@2ohms -3db
250w@4ohms -6db
125w@8ohms -9db
62.5w@16ohms -12db

so when you were wired for a 4ohm load you were down 6db, which sounds significantly quieter, and at 16ohms you were down 12db, which would sound under half as loud. The other thing to consider is when the level of the bass is noticable below that of the rest of the frequency range, you will percieve it as being even quieter than it really is.

So power does matter, except for when it dosen't, clear as mud eh?

WhiteBird00

iTrader: (4)

Using your example, going from 1-ohm to 4-ohm causes a 6dB drop in volume which is cutting the volume in half (for the average ear at mid-range/vocal frequencies). Going to 16-ohms causes an overall drop of 12dB which the average ear hears as 1/4 the original volume. Also, at 16-ohms he had probably reduced the power to the point where he was underdriving the subs causing them to sound bad as well as quiet.

B T

>>>>
Actually that makes sense.

Using your figures above for reference then if it's true that there is a 3 db loss in volume ( 1/4 of the sound volume being lost ) going from 2 ohms to 4 ohms and a loss of 250 watts from the amp...

Then to get the same volume as in 2 ohms I would need to either replace that speaker with a 4 ohm speaker that is 3db higher in sensitvity to make up for the loss of wattage ( or ) leave it at 4 ohms and grab an amp that has an increase of 250 watts?

The pool is getting muddy again...

So if this is correct, then when replacing the sail panel speakers to obtain the same volume as the oem speakers produce in 2 ohms, I would need either a 4 ohm speaker that has a 3 db higher sensitivity than the oem unit to make up for the lack of wattage to get the voulme back to stock or (modify) the amp to have 1/4 more power with the 4ohm speaker that has the same sensitivity as the oem unit???

I guess I just still don't get the whole idea, also since the higher ohmage of a speaker has more windings on the coil, wouldn't that hinder sensitvity purely based on the extra weight factor alone, ( I know we are not talking a pound ), but it's still weight the driver has to be able to control correct?



Am I just looking at it from the wireing perspective again?

TA guy

iTrader: (1)

Um, not 1/4 of the sound, but yes 3db loss due to the power being cut in half, assuming the 2 and 4ohm load have the same (1W@1M) sensitivity rating. If both drivers have the same (2.83Vrms@1M) sensitivity rating, then there will be no difference in SPL when you cut the power in half. If you don't know which rating you are looking at, then it is a useless number.

For (1W@1M) ratings, You got it

Theoretically Yes. But again you must understand sensitivity as more than just a single spec for that to be useful, especially for subwoofers. Typically the lower a driver will play in a given enclosure, the lower the sensitivity number will be, however, the driver with the lower sensitivity quite often will play a 40Hz (note: there is nothing special about 40Hz, this it just for illustrative purposes) note louder that the driver with the higher sensitivity even though they are both being given the same amount of power. Also how the driver performes on the low end will vary based on the application. So in short, don't worry about the sensitivity.

No, Double the power.

The extra windings in the magnetic gap are able to produce more force with less power, thus the increase in sensitivity. Yes the moving mass would go up a smidge "all else being equal", but the increase in moving mass is not nearly as significant as the extra force created by the higher magnetic force.

fredmr39

wow...over 1,100 views in 12 days!! Thanks!!!

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VENTED POLE / SPACE BEHIND SPEAKER

Drilling the hole as illustrated in the pictures above is NOT necessary. The minimum required space that there should be behind this port, or "vented pole", is .25". If you use a .25" spacer, that is not enough room.....however, if you use a .50" spacer, there is obviously at least .25" of space behind the speaker. IF you for some reason CANNOT use a .5" spacer or drill a hole with a smaller spacer...do the best you can. Drill at least a small hole, and space it as far as possible.

^NOTE: Having LESS than .25" of space behind the speaker, or even completely plugging up the port will NOT cause any physical damage to the speaker. The only thing that would/could suffer is sound quality. Plugging it entirely can create some odd back pressure that would DEFINITELY be noticeable in a ported box, and may actually end up being audible in a sealed enclosure as well. I do not know how it would affect the sound in an infinite baffle application.

***Pole vents are commonly used as means of cooling (speaker motion dissipates heat away from the voice coil and magnet steel). Pole vents also are the most common method for relieving pressure buildup (under a dust cap/diaphragm). The latter reason is why it can affect sound...and though it WOULD aid in heat dissipation, heat is dissipated other ways and on this particular speaker, according to eD, it shouldn't make a difference as far as heat dissipation.


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FREQUENCY RESPONSE

Frequency response on the drivers is 20Hz~500Hz.

If you plan to use them as a dedicated midbass - I would cross them over somewhere around 250Hz.

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SENSITIVITY

SPL: 85 dB is @ 1W/1m

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B T

SPL: 85 dB is @ 1W/1m
>>>>

oo oo, I think TA Guy mentioned something about lower would be better for a sub.
I could be confusing the ohm thing again though, so...

Anyway, I decided to try this whole Elemental project as described by Fred as best I can. I'm going to do my best to follow it to the letter.

I ordered 2 D4's for replacement of the sails, I after the install I will report back to you guys how I think it sounds.

I know you can't ask much from a 6.5 "Woofer" but those specs for some reason are starting to grow on me.

fredmr39

Not better....just that it's not common to have high sensitivity ratings on a sub. Most are in the area of 84-86 dB @ 1W/1m.

WhiteBird00

iTrader: (4)

B T, you have the right idea - it's just that the decibel scale for measuring volume (sound pressure level) is not linear - it's logarithmic. So, even though a 6dB reduction equates to about half the volume, a 3dB drop doesn't equate to a 1/4 of the volume. However, I will often use values similar to that just for illustration purposes because it makes it easier to demonstrate the effect of power changes.

This sentence confuses me, I think something is missing from your statement. Obviously reducing power by half will have an impact on volume (-3dB) if sensitivity and everything else is equal.

97MysticZ

iTrader: (16)

I have a couple questions....

1. I looked at the elemental website on these speakers, is that $75 for just ONE speaker or is it a pair??

2. What do you use to cut the round hole in the metal behind the speaker?

3. Can someone kind of explain the difference between midbass and midrange speakers? The stock speakers are considered mibass speakers right? Have you all determined if these speakers are good mibass speakers or are they just more of a small sub? Will these have a more "full" sound if you use the speaker wires from the hatch (in a camaro)???

fredmr39

had a bit in the center and a cutting pattern on the outside (circular). If yo1. Price is per speaker (singular).

2. You could use a 1" drill bit (or larger if you have one...don't go out and purchase one just for this though...they are about $30). I happened to have a hole saw - however, if you use a .5" spacer...the hole is not necessary.

carbide tipped hole saw


3. Frequency spectrum we can hear is approximately 20Hz - 20,000Hz

Mid-range speakers typically reproduce frequencies between 300Hz - 5,000Hz.

Mid-bass speakers can be any lower frequencies like 250Hz-500Hz, or lower ranges....whatever the listener likes. Either way, they stay in the lower bass range while midrange speakers cover much more of the range/higher frequencies.

obviously this is VERY general...


IMO...they are MORE of a small sub than mid-bass speakers. They will however cover all of the mid-bass frequencies that the stock speaker covered (obviously), but their range just extends down lower and they hit harder compared to stock. Pulling the hatch signals forward would not be a good idea, since it would only reproduce frequencies up to about 500Hz anyway....

TA guy

iTrader: (1)

If both drivers have the same (2.83Vrms@1M) sensitivity rating, then there will be no difference in SPL when you cut the power in half. If you don't know which rating you are looking at, then it is a useless number.

The 2.83Vrms@1M is a very commonly used sensitivity measurment, it corrisponds to 1W@8ohms, 2W@4ohms, or 8W@2ohms. This is very often used as it by manufacturers as it is a ligitimate way to advertise a higher sensitivity number. Like I said, you have to know what you are looking at or it is a useless number.

WhiteBird00

iTrader: (4)

Okay, I think we're saying the same thing. If you have two speakers with the same efficiency and the same impedance then cutting the power by half will reduce volume by 3dB. If you have two speakers of the same efficiency but one is half the impedance then you can run half the power through the lower impedance speaker and get the same SPL as the higher impedance speaker.

melchoir

iTrader: (4)

I am extremely interested in doing this conversion as my stock sail panels are blown.
Is there any simple guide/instruction you could give on making the 1/4" spacer? That's my main concern. I don't have any saws, just mechanical tools. (Wrenches/sockets)

I'd be willing to purchase one if they could be pre-made easily.

fredmr39

No buddies or anything that can lend you a jig saw? I have a post somewhere I'll find with places you can buy pre made spacers, but they are circular...and the place you are putting them in isn't exactly a perfect circle and I do not know exact dimensions (and am not by this car for a month or so)... so what I'm saying is - even if you get one pre-made, it would probably require modification. Dimensions for the speaker can be found in the speaker link in post #1.

There is another option that may work better for you. Spacers have been successfully made with a foam core material, and all you would need to shape that is a box cutter or knife.

EDIT: See post below.