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Why So Cereal?
09-21-2011, 10:12 PM
Looking to do a sq setup in my tC, I have 2 Dayton ho 10s on the way. Optimal recommendations have been .7 net tuned to 29hz.
Do I need to build separate chambers for each sub? Or can they be common chambered? They will be getting about 450-500rms each. Also if separate chambers what size Aero ports? Thinking 2". If common chambered will a single 4" Aero work? Which will have better sq?

Max dims are 42 wide, 18 deep, 11 high.

dontbeaprix
09-21-2011, 10:46 PM
You could run slot ported i imagine.

Why So Cereal?
09-21-2011, 10:59 PM
Common or separate chambers

dontbeaprix
09-21-2011, 11:01 PM
I think one of the box builders should chime in

Why So Cereal?
09-22-2011, 12:10 PM
Bump

matt_bennett05
09-22-2011, 12:21 PM
Im about to pm you some info on a guy from valdosta that is a good guy... hold on (btw im from Cairo)

Moble Enclosurs
09-22-2011, 02:52 PM
I have actually calculated the ports, if you were to use two of them, at being 2.67" each, or two 3" ports would work. The overall diameter based on the drivers mechanical parameters, gives me 5.36IN ports for both drivers. This is a minimum port for SQ, so again two 3" ports would be great. Or a common chamber with a 6" aeroport would be acceptable. The differences of that and a single chamber are the efficiency and tuning. With two chambers, you only gain around 3-5dB with the added chamber, along with the limited ability to get a lower tuning if required. With a single chamber, you can get more control over tuning and such. I would overall then, recommend a common chamber with a single 6" aeroport, if you want to use the aeroports. Hope that helps!

Why So Cereal?
09-22-2011, 02:58 PM
I have actually calculated the ports, if you were to use two of them, at being 2.67" each, or two 3" ports would work. The overall diameter based on the drivers mechanical parameters, gives me 5.36IN ports for both drivers. This is a minimum port for SQ, so again two 3" ports would be great. Or a common chamber with a 6" aeroport would be acceptable. The differences of that and a single chamber are the efficiency and tuning. With two chambers, you only gain around 3-5dB with the added chamber, along with the limited ability to get a lower tuning if required. With a single chamber, you can get more control over tuning and such. I would overall then, recommend a common chamber with a single 6" aeroport, if you want to use the aeroports. Hope that helps!

yea, someone else told me about the 3" aeros as well. Im thinking 29hz tuning should be low enough but I'll double check to be sure. If think I am leaning more towards the separate chambers since I am already not giving the subs their rated rms, the extra efficiency and db gain might be pretty helpful atleast in the lower bass regions. Such as 20hz organ tones in some songs. and crossovers can always help me keep the subs from reaching to high. But if all else fails, the common chamber with 6" aero might be the way I go. thanks

Why So Cereal?
09-23-2011, 02:43 PM
went to try and see how to tune the ports and...in order to get the tuning I wanted, the ports have to be too long.
But I would like to port around 29-30hz as this yielded the best results for a flat response with these subs...any suggestions?
was looking at about 2 cubes (separate chambers, 1 cube each gross) then 3 in port per chamber

Bumpin' Goalie
09-23-2011, 02:57 PM
With the small volume required, and the low tuning desired, it may be easier to utilize a standard slot or kerfed port.

Moble Enclosurs
09-23-2011, 02:59 PM
went to try and see how to tune the ports and...in order to get the tuning I wanted, the ports have to be too long.
But I would like to port around 29-30hz as this yielded the best results for a flat response with these subs...any suggestions?
was looking at about 2 cubes (separate chambers, 1 cube each gross) then 3 in port per chamber

I want to make sure that you know, the reason it yielded the best results is due to the enclosure they were previously in. This can change upon the design, so my recommendation is to explore the possibility of using slot ports as well, and if that is not a possibility, then I can look at your design specs and figure something more accurate for you if you like. But, keep in mind that there will always exist some limitations, and going for that low of a tuning may be improbable for what you are asking for, not sure yet. Because for 2 cubic ft, especially in separate chambers(which is why I recommended a common chamber) will be tough to get that low of tuning properly without decreasing the area of your ports, which I would not recommend due to the noise factor involved after what I had calculated for a minimum area.

So, I can either request that you purchase a design from myself or others, or let me do some little bit of free math for you to get something more probable. Sound reasonable?

05trailblazer
09-23-2011, 03:02 PM
^^ he knows what he's talking about

Bumpin' Goalie
09-23-2011, 03:05 PM
.65 @ 30hz seemed to be a well received base over on DIYMA. However, they ran into the same issues of port lengths and decided slot port, though not space effective, was the best solution for most applications.

You could also consider external ports, if you must.

hispls
09-23-2011, 03:20 PM
Tuning even a 2 cube volume to 30hz will be difficult (as everyone has said, due to just fitting that much port in). Have you considered a couple 12" passive radiators?

Xsprehunz Audio
09-23-2011, 03:25 PM
Just wanting to know if you are planning on competeing with this system or every day listening.. I am not trying to be a D#$K but 29 hrtz. for daily or even competing is kinda low . I did see where you said you wanna use areo ports but try the RE Audio Calculator . it will give you all kinds of options to play with ..

Moble Enclosurs
09-23-2011, 03:34 PM
I agree as well that 29Hz is pretty low to tune to for either situation, but if that is your desire, then let's see if it can work. As others have said, and I, that a slot port configuration may be more worth the time due to the ability to go around the enclosure for added length, and also, importantly, to add square area if needed to reduce port noise. It is why they are so popular. But let's try to stay away from generalization in designs. Every design will have it's own limitations, so considering all factors and not just concentrating on port configuration is important. For this, I would not recommend any of these port programs or calculators,a s they are very general.....can be effective in a conventional matter, but more accuracy is needed for optimum output than a simple formula that in most cases do not consider the driver installed.
So, the information we all have given you is all great to keep in mind. Keep your options open. In some cases, I have figured that a sealed enclosure may be more applicable even though the person may want a ported....sometimes it just doesn't work. But again, options open and with a little help like you have been getting so far from all of us, you will get there.

Bumpin' Goalie
09-23-2011, 03:41 PM
Just wanting to know if you are planning on competeing with this system or every day listening.. I am not trying to be a D#$K but 29 hrtz. for daily or even competing is kinda low . I did see where you said you wanna use areo ports but try the RE Audio Calculator . it will give you all kinds of options to play with ..

Keep in mind this is for sound quality, and not so much sheer output. The goal is a flat response curve with accurate musical reproduction.

Why So Cereal?
09-23-2011, 03:44 PM
Keep in mind this is for sound quality, and not so much sheer output. The goal is a flat response curve with accurate musical reproduction.

exactly, which is why i was so set on the 29-30hz tuning that was recommended over on diyma. not trying to be stubborn or anything lol. Just if at all possible, i would like to get around 30hz tuning for SQ

Why So Cereal?
09-23-2011, 03:53 PM
so this is what i came up with after some more number crunching:
2.5 cubes net, common chambered
1 6" aero 30" long port firing to driver side of trunk

too much space for the subs?

Bumpin' Goalie
09-23-2011, 03:57 PM
Almost double of your original plan, no? Why not use the extra space for a slot port?

Moble Enclosurs
09-23-2011, 04:02 PM
Almost double of your original plan, no? Why not use the extra space for a slot port?

Much agreed. These drivers together I have calculated they they only need 1.012 cubic ft TOGETHER for optimum compression at 29Hz. So, you have plenty of room for a slot port if this can be done correctly. Most will say 1 cubic ft is too small for a couple of tens, but the original post says .7 per sub, so my calculations are .2cubic ft off of recommended(by the way, never use recommended-as just shown, they can be off a bit). These will actually be great in .5 cubic ft each, but the problem then lies in being able to fit them in that space, lol. Again, limitations will change everything. So, go as small as you can for the compression area and use the rest for port, just make sure the port matches the compression or it will cause inaudible and maybe some audible problems.

Bumpin' Goalie
09-23-2011, 04:26 PM
Much agreed. These drivers together I have calculated they they only need 1.012 cubic ft TOGETHER for optimum compression at 29Hz. So, you have plenty of room for a slot port if this can be done correctly. Most will say 1 cubic ft is too small for a couple of tens, but the original post says .7 per sub, so my calculations are .2cubic ft off of recommended(by the way, never use recommended-as just shown, they can be off a bit). These will actually be great in .5 cubic ft each, but the problem then lies in being able to fit them in that space, lol. Again, limitations will change everything. So, go as small as you can for the compression area and use the rest for port, just make sure the port matches the compression or it will cause inaudible and maybe some audible problems.

Yup, that just about sums it up.

Bumpin' Goalie
09-23-2011, 04:26 PM
Much agreed. These drivers together I have calculated they they only need 1.012 cubic ft TOGETHER for optimum compression at 29Hz. So, you have plenty of room for a slot port if this can be done correctly. Most will say 1 cubic ft is too small for a couple of tens, but the original post says .7 per sub, so my calculations are .2cubic ft off of recommended(by the way, never use recommended-as just shown, they can be off a bit). These will actually be great in .5 cubic ft each, but the problem then lies in being able to fit them in that space, lol. Again, limitations will change everything. So, go as small as you can for the compression area and use the rest for port, just make sure the port matches the compression or it will cause inaudible and maybe some audible problems.

Yup, that just about sums it up.

Why So Cereal?
09-23-2011, 04:43 PM
came up with 34 wide, 10 high and 12.6 deep (internal measurements) gave me about 2.479cubes gross.
with a 6x30 aero ported firing to driver side gave me my 30hz tuning. would this work?

Why So Cereal?
09-23-2011, 04:47 PM
or maybe two 3" aeros with half the length each

supermaxx123
09-23-2011, 04:55 PM
As mentioned, passive radiators will be your best bet, to stay small

Moble Enclosurs
09-23-2011, 04:58 PM
or maybe two 3" aeros with half the length each

The length does not directly relate to the separation of the port area. If you were to use two 3" ports instead of a 6" port, the square area is the same, so the length of each should be the same length as one, not shorter. If you make the two 3" ports shorter, the tuning will increase.

Moble Enclosurs
09-23-2011, 04:59 PM
As mentioned, passive radiators will be your best bet, to stay small

For SQ based, this is a good idea, might want to consider that as well.

Bumpin' Goalie
09-23-2011, 05:05 PM
For SQ based, this is a good idea, might want to consider that as well.

But keep in mind that introducing PR's will generally force an increase in at least 1 dimension, requiring others to shrink to compensate and keep the volume desirable. It may or may not be convenient while trying to maintain such a small internal volume.

wenn_du_weinst
09-23-2011, 05:16 PM
if you do not have time alignment on your sub channel passive radiators will not work.
also with these low xmax subs you can get away with much less port area. Lastly are you sure 29hz will play flat in car? that sounds way low with out a separate higher tuned sub woofer

Moble Enclosurs
09-23-2011, 05:39 PM
if you do not have time alignment on your sub channel passive radiators will not work.
also with these low xmax subs you can get away with much less port area. Lastly are you sure 29hz will play flat in car? that sounds way low with out a separate higher tuned sub woofer

This is true. The vehicle will determine more of the LF response than the enclosure will. This can be calculated for, optimally, if desired and I would not recommend a design without that information. This is why we all have said 29Hz seems low. But again, this is always your decision, not ours.

As far as passive radiators, this is true, the delay will be a factor, but unlike ported designs, the resonances within the enclosure are less of an issue for output, due to compliance. So, you will not have major phasing issues like you do with a conventional design, but not to say it is not an issue, by all means. But other factors of a PR make resonances less of an issue in such a small space. This would be more of a concern in a larger acoustical area than a vehicle. Either way, it is definitely something to look at, as all variables are. SO, that being said, great point.

wenn_du_weinst
09-23-2011, 05:43 PM
It's usually over looked so figured I'd bring it up

Bumpin' Goalie
09-24-2011, 02:33 AM
I'm guessing that software only showing the roll off as frequency decreases is being used by the majority of folks here. Unfortunately, a combination of that and improper abilities to properly reproduce 60-120hz (without dragging the imaging to the rear) can lead to some problems.

That being said, it is always easier to EQ something down than up. :) I am aware of the enclosures used and loved over on DIYMA for these woofers. However, vehicle-dependent gains and losses are not always calculated for.

But to be fair, these issues and some of the more advanced sciences that come along with properly utilizing PR's are not too many people's priorities. What may sound superb to some may sound sub-par to others. Such is the perception aspect of car audio.

06goat
09-24-2011, 03:51 AM
You could run slot ported i imagine.

To much port noise for a SQ build

Moble Enclosurs
09-24-2011, 02:33 PM
To much port noise for a SQ build

The type of port is not a factor of port noise. You can have port noise in any port of insignificant size. Being a slot port is not a factor in "noise", but the SIZE of the slot port will be the factor, along with the ratio of length and width. Is that kinda what you mean?