Hi Everyone,
For the past 3 years, I have competed in Car Audio shows and did well in the area of bass with my lexus is250 (2006) and the original ski hole (140db-144db of front windscreen). I started my journey in SQ last year with Deaf Bonce AP Neo 6.5s and W81 8s. The car sounds really good and all, but I would like to upgrade to 8s only and was wondering if it makes sense to modify my door chassis to take 8s and fabricate the panels. The reason for this, is to ensure I remain within the cone area of 60in - as part of my vehicle class (stock with minimal modifications). What do you think?
Another question, is which 8s do I go with for midbass and midrange to have the best overall audio effect at low and loud volume. I was thinking of either the B&C Speaker 8PE21 or Eighteen Sound 8M400F for midrange and Beyma 8MC500Nd for midbass. What do you think?
Thanks for any input or suggestions.
For the past 3 years, I have competed in Car Audio shows and did well in the area of bass with my lexus is250 (2006) and the original ski hole (140db-144db of front windscreen). I started my journey in SQ last year with Deaf Bonce AP Neo 6.5s and W81 8s. The car sounds really good and all, but I would like to upgrade to 8s only and was wondering if it makes sense to modify my door chassis to take 8s and fabricate the panels. The reason for this, is to ensure I remain within the cone area of 60in - as part of my vehicle class (stock with minimal modifications). What do you think?
Another question, is which 8s do I go with for midbass and midrange to have the best overall audio effect at low and loud volume. I was thinking of either the B&C Speaker 8PE21 or Eighteen Sound 8M400F for midrange and Beyma 8MC500Nd for midbass. What do you think?
Thanks for any input or suggestions.
How low do they need to play?
How loud do they need to play at their lowest frequency? "low and loud volume" are very relative/user specific. There's not enough data there to make a suggestion.
Do you need high sensitivity?
A Purifi 6.5 inch has twice the volume displacement of the B&C 8PE21. Purifi's Fs is also much lower, but its sensitivity is lower and price is higher.
How loud do they need to play at their lowest frequency? "low and loud volume" are very relative/user specific. There's not enough data there to make a suggestion.
Do you need high sensitivity?
A Purifi 6.5 inch has twice the volume displacement of the B&C 8PE21. Purifi's Fs is also much lower, but its sensitivity is lower and price is higher.
Or to say it differently, one could also get two other woofers for the same or even a (much) lower price.
At the same SPL, this would mean distortion is 6dB less (or half in percentage).
Beating a good quality 8 inch with a single 6.5 inch is a difficult thing to do.
You need to have at least around 9-12mm to compensate for the smaller Sd.
That is just only based on pure output, not distortion figures.
Using two 6.5 inch woofers is far more effective.
If you want to do low-end as well, 8PE21 is not the way to go.
Hi Matt,
Indeed, I'll try to provide some more details. An ideal low would be between 110hz and 160hz and high about either 3k-4.5khz. No need for high sensitivity.
The amplifiers are 2000x4 @ 2ohm per channel. The gain will be set correctly using an oscilloscope for the speaker/amplier. I have a kenwood headunit which outputs 5v on RCA and goes into a JL Audio TwK-88 (DSP) before the amplifiers. The DSP has the following 6 inputs (front high and mid), (rear high and mid) and lows for subwoofers. DSP volume is usuallly limited between 25% for low and 75% for high, but the headunit is fixed at 34 out of 35 volume.
Hope the above helps.
Indeed, I'll try to provide some more details. An ideal low would be between 110hz and 160hz and high about either 3k-4.5khz. No need for high sensitivity.
The amplifiers are 2000x4 @ 2ohm per channel. The gain will be set correctly using an oscilloscope for the speaker/amplier. I have a kenwood headunit which outputs 5v on RCA and goes into a JL Audio TwK-88 (DSP) before the amplifiers. The DSP has the following 6 inputs (front high and mid), (rear high and mid) and lows for subwoofers. DSP volume is usuallly limited between 25% for low and 75% for high, but the headunit is fixed at 34 out of 35 volume.
Hope the above helps.
What's the reason for the needed mods? No longer competitive?
If so, where are you getting beat by the competitors?
If so, where are you getting beat by the competitors?
@Perry Babin
The AP-M67AN from DB doesnt go lower than 200hz and the judges and other audio enthusiast indicate I need more body and depth in the door speakers.
The AP-M67AN from DB doesnt go lower than 200hz and the judges and other audio enthusiast indicate I need more body and depth in the door speakers.
@b_force
I like the idea of 2 x 6.5s, and once had a 6.5 doing the upper mid and 8 doing low mid. But this wasn't allowed for the competition class, I had to move the 8s to the rear deck of the car to compete.
One of the reason I am trying to have a more permanent solution and remain within the cone area of 60in.
I like the idea of 2 x 6.5s, and once had a 6.5 doing the upper mid and 8 doing low mid. But this wasn't allowed for the competition class, I had to move the 8s to the rear deck of the car to compete.
One of the reason I am trying to have a more permanent solution and remain within the cone area of 60in.
@Perry Babin
either 37hz or 38hz.
I don't recall the voltage though, it might be written somewhere.
I did the 144 @ 43hz with 12.1v. A different enclosure this time around.
either 37hz or 38hz.
I don't recall the voltage though, it might be written somewhere.
I did the 144 @ 43hz with 12.1v. A different enclosure this time around.
This is why I never enter any competitions. 😀 😀
Why would I get a sub-optimal result because of some silly subjective rules? 😀 😉
Boiled down to a basic level (and ignoring some things), volume displacement determines maximum output. In free space, you wind up with a plot like this:
The higher you cross them over, the more output you can get out of them before running out of excursion. Cabin gain has to be added to these numbers also.
In some high SPL vehicles people want the midrange and midbass to keep up with their subwoofers. Other people (that actually want to be able to hear long term) only need those drivers to play at sound quality levels. I still can't figure out where you fit on that scale.
With multiple DSP presents, it's easier to run higher high-pass cross points in high SPL mode, and lower cross points for sound quality. Doing that can give you more output capability when you want it.
Your previous door speakers had high resonance, high sensitivity, and are basically pro-audio style drivers. This normally comes with low Xmax as well (like with the B&C ones). When this is carried far enough, you get into true midrange drivers, not midbasses like you typically want in a car. Pro-style drivers typically handle high power better, have larger voice coils, etc., so they have benefits. It all depends on how you want to use them.
I'm not suggesting Purifi is the right way to go for you, it's just an example of a high displacement, low distortion 6.5 inch. If you want to modify your doors and make an 8 inch fit, that's certainly an option, and some people like going more custom. Others are happier to try to fit things in a standard configuration - which is why I threw the 6.5 inch high displacement idea out there.
The higher you cross them over, the more output you can get out of them before running out of excursion. Cabin gain has to be added to these numbers also.
In some high SPL vehicles people want the midrange and midbass to keep up with their subwoofers. Other people (that actually want to be able to hear long term) only need those drivers to play at sound quality levels. I still can't figure out where you fit on that scale.
With multiple DSP presents, it's easier to run higher high-pass cross points in high SPL mode, and lower cross points for sound quality. Doing that can give you more output capability when you want it.
Your previous door speakers had high resonance, high sensitivity, and are basically pro-audio style drivers. This normally comes with low Xmax as well (like with the B&C ones). When this is carried far enough, you get into true midrange drivers, not midbasses like you typically want in a car. Pro-style drivers typically handle high power better, have larger voice coils, etc., so they have benefits. It all depends on how you want to use them.
I'm not suggesting Purifi is the right way to go for you, it's just an example of a high displacement, low distortion 6.5 inch. If you want to modify your doors and make an 8 inch fit, that's certainly an option, and some people like going more custom. Others are happier to try to fit things in a standard configuration - which is why I threw the 6.5 inch high displacement idea out there.
Last edited: