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View Full Version : 4th order folks, tell me if I am on track!



Jroo
08-19-2011, 10:24 AM
here are the specs for my 2 old 10's.

Power Rating RMS Cont. 250 Watts
Max Power Rating-Unclipped Amp 350 Watts
Freq Response 25-150 Hz
Nominal Imp 8 Ohms
Voice Coil 2" 4 Layer
FS 25.18 Hz
Qms 8.8040
Qes 0.3579
Qts 0.3439
Vas 67.30 Liters
Cms 0.3994E-03 M/N
Re 6.93Ohms
BL 17.505 Newtons/Amp
Sd 0.034636 Sq. m.
Mms 0.100017 Kg
Hvc 0.980"
Hag 0.375"
Xmax 0.303"
Xlin 0.605"
Ref Eff 0.2885%

Here is what I have box related.
My max H is 13 inches, width is 16 inches, and lenght is 38 inches

Sealed side is .936
Ported side is 2.042
Port is 55 square inches tuned to 55hz.

Trying to play music from 70 down and be musical. Not worried about metering at all. Will be giving the pair a true 800rms from an old Rockford 800 A2. What do you think so far?

pro-rabbit
08-19-2011, 10:28 AM
I would bring your tuning down some for a daily setup maybe 45-50

I can not comment on the specs though as I'm on my phone and I don't feel like doing math in my head..far to early for that.

Jroo
08-19-2011, 11:12 AM
I had a feeling the tuing was too high. If I brought the tuning down, I would have no issues playing 70 down? I would like it to play flat if possible.

pro-rabbit
08-19-2011, 11:23 AM
I had a feeling the tuing was too high. If I brought the tuning down, I would have no issues playing 70 down? I would like it to play flat if possible.

If you want more control then I would suggest a 6th order which will typically have a more "smooth" response curve. A 4th order by nature will have a decently sized peak.

Jroo
08-19-2011, 04:32 PM
i was told a few times these woofers would do very well in a 4th order. What are people looking at to say that they are 4th or 6th order. My 4th could have a peak as long as it down lower.

i2ain2thunder
08-19-2011, 05:45 PM
yeah I'd tune that lower I always like lower tuned ports. Higher tuned ones just don't give the bass enough depth to me.

surreal
08-19-2011, 06:26 PM
Firstly and importantly, what vehicle is it being placed in, and where? This will have a big effect on cabin gain which youll need to get an idea for to shape the response of the enclosure.

Jroo
08-21-2011, 10:07 AM
going in the hatch area of a Pathfinder.

Jroo
08-22-2011, 11:40 AM
another question. Does port up or back matter with bandpass, like it does with ported. I was just going to do port up.

Jroo
08-23-2011, 07:05 PM
any thoughts?

Flastrongman
08-23-2011, 07:15 PM
I'd go bigger on the sealed section and smaller on the ported because of the weak motors on those subs you'll have almost no lows with the specs you listed.

Jroo
08-24-2011, 12:54 PM
how much would the Fs play on going low. These subs are basically the credence build house no named solobarics. When I called on them, they said think the old round solobaric with a generic label on them. I would agree that compared to newer subs, these dont have the motor that is out there now. So a larger sealed vs smaller ported aids in how low a bandpass will play?

Jroo
08-26-2011, 09:49 AM
Ok, so I played with a few online calculators and took the average of what they all said. Each gave me something differernt.

Sealed side 1.17
Ported side 0.57
Tuning Frequency 43.87

They are saying this will play roughly 76 Hz to 25 Hz. These are looking more like the recommendations that Flastrongman said by going way larger on the sealed side and smaller on the ported. I also figure I will keep the port around my original 55 square inches. What do you think now?

Flastrongman
08-26-2011, 11:05 AM
that's too small now. just do a 1:1 ratio if you want them to have a good freq response. 1.5 sealed/1.5 ported tuned to around 50hz

Buck
08-26-2011, 12:24 PM
Is it just me or does these parameters steer more towards a 6th order than a 4th?

Flastrongman
08-26-2011, 01:34 PM
the qts makes them pretty well suited for 4th

surreal
08-26-2011, 06:38 PM
They have an EBP of ~70, with a rather high VAS. A 6th order would be a good option, however it would be large.

Most of the calculator will give you a flat response that looks good, but changes a lot in vehicle. As I believe FLA said, make the ported a little larger and it should work out well in vehicle. Your car will most likely have a lot more low end gain. You can combat this some by moving the enclosure further or closer from your hatch which should have an effect on upper end gain.

Oh - Also remember, excursion goes crazy down low. Dont forget to factor in SSF in your response if you dont want to kill your sub!

jake760
08-27-2011, 01:04 AM
I built a 4th order for a friend for 2 cheap pioneer 10's, did 1.6 sealed, 2.3 ported tuned to 45hz. Sounded amazing, very clean and dropped right down to 25hz with authority. Just something to consider.

Jroo
08-30-2011, 11:18 AM
Since I didnt want to end up with a 3 cube box, I'll run this. I am going to ISO the woofers and run .75 on the sealed side and 1.5 of the ported side. Give the 50 square inches of port tuned to 50 and run the port firing straight up.

Jroo
08-31-2011, 01:06 AM
Thoughts on this

Moble Enclosurs
08-31-2011, 10:40 PM
They have an EBP of ~70, with a rather high VAS. A 6th order would be a good option, however it would be large.

Most of the calculator will give you a flat response that looks good, but changes a lot in vehicle. As I believe FLA said, make the ported a little larger and it should work out well in vehicle. Your car will most likely have a lot more low end gain. You can combat this some by moving the enclosure further or closer from your hatch which should have an effect on upper end gain.

Oh - Also remember, excursion goes crazy down low. Dont forget to factor in SSF in your response if you dont want to kill your sub!

EBP is only a basic start to figure for proper alignment. I do not consider it a way of determining a design goal or type of enclosure. Any driver can be used for a desired response, it's just a matter of the limitations that follow that become the deciding factor. In it's simple form, EBP does not account for what is needed to be considered efficient or not. it's just a basis for the more simple design calculations.

Moble Enclosurs
08-31-2011, 10:48 PM
Also, VAS, though considered the acoustical compliance, can be controlled with much more of a variation from its basis volume by tapered lines. so even this is not true for all designs. The basic parameters of a driver is a starting point, but only if you only consider constant port area, specific volume chambers, and very basic "sealed" or "ported" design ideas(which ported covers many box types). It is only a minor factor in the full final response of any driver/box combination. So, with all do respect, I do not use these for telling me what physical parameters will exist in the design. Let all of the factors give you what you need for a response and output. Try all design ideas for a driver. You may be surprised that EBP and VAS will either be incorrect, or dramatically different, depending on the desired response and output.
Most of these basic ideas of figuring for proper design types are based on Q factors of a nominally flat response.

Jroo
09-03-2011, 06:31 PM
No offense, but I have no idea what you are saying? Are you telling me what I am trying is going to work or if you saying that the advise on here *****? Basically I have 1.5 sealed and 1.5 ported at 50 Hz. To kill space I am isoing the subs so my sealed section will be 0.75 give or take.

Moble Enclosurs
09-03-2011, 06:40 PM
No offense, but I have no idea what you are saying? Are you telling me what I am trying is going to work or if you saying that the advise on here *****? Basically I have 1.5 sealed and 1.5 ported at 50 Hz. To kill space I am isoing the subs so my sealed section will be 0.75 give or take.

If this was for me, no, and no. I cannot say it will work without calculating for it myself, and as far as the advice, it does not ****, lol. Just evolving, that's all. No one is wrong about anything so far. Just more goes into it than basics and generalization. But if you are only concerned about something basic, that is completely acceptable of course. Basics sometimes are enough, and sometimes they should be depending on what you are looking for. So, if you think it will work, try it out. If it doesn't, tell us why it didn't work. maybe it will help with knowledge-base on here.

galacticmonkey
09-07-2011, 04:46 PM
For a pair of low power 10s going for a flat response, Id shoot for around 2 cubes sealed, 2 cubes ported. 40in^ of port @ 45hz.

Jroo
09-11-2011, 06:03 PM
Thanks galacticmonkey. Will it matter is the port is up or back in the hatch? What type or range will tuning at 45hz give?