[Invinsible]

Advantages and disadvantages of Dual 8" setup compared to single 10" ?

Well, I have been thinking this for quite sometime now. Have gone to various forum, I have found some info but not much on 2 8" SUB V/s 1 10" sub.
I Plan to get this in a Fabia. Currently I have a Morel Dotech Ovation Comps in front along Alpine 550 amp where the 3rd and 4th ch. drives the current sub under bridge mode putting out 250RMS. The current sub is more like custom made neodymium magnet with just 2.8" Mounting depth at present is .3 cu.ft. box.
It has started to sound little muffled since past few weeks. Tried various Xover setting but of no help.

So, in order to enjoy music better have decided to upgrade my sub. Now, here's what I have been thinking.
1. To get 2 8"sub in a sealed / Ported enclosure in order to get more tighter, accurate, musical bass.
2. To get 1 10" sub incase 8" subs are not available.
3. What will be better to get tighter, punchier bass at the same time not getting boomy.

a) Would like to know whether dual 8" sub will be better than 1 10" in terms accuracy, tighter bass? Now I know many would say to get 12 or 15 or dual 10" and stuff. ALso, I would want to save booth space as much as possible.
So decided of this option. I listen to all kinda music from Rock, Alternate Rock, House, at times apna bollywood.

b) Now I do understand that single 10"sub will go much lower compared to dual 8" sub due to the surface area. But may be with dual 8" sub I can get much better bass, accuracy, space saving. Also, dual 8" would move more air in the booth, thus would go little louder as compare single 10". Also, I agree that with the Enclosure size of dual 8" I can very well go for a single 10" or a 12" sub. But, the question with both having similar enclosure size what would be better option? But will the Dual setup give me better accuracy at sometime could it go little louder as compared to single sub? I am looking more of SQ than anything else.

I would like to know what are the advantages of dual 8" sub compared to single 10 or 12" setup?
Which 8" subs will do a good job, IMAGE DYNAMICS ID series / POLK audio DB series / Rockford fosgate Punch stage 2 / any other option?
BUDGET : Within 15-18K.

Now I do understand since I would powering them under bridge mode would have to pick Two 8" 4 ohms DVC SUBS and connect them in series. That way will get 4ohm out of them.

I would like to know if any one here has any experience with dual 8" setup?
How good will it be in a hatchback? What are your views on it? Which Make will be a better choice? Looking for something that would gel with my front comps.

Please Help!

Thankyou,
Regards.

[abhibh]

Its about personal preference regarding 2 x 8" or 1 x 10"

If space is no constraint and the subs are within budget then 2 x 8".

I have heard ID 10" and Polk (Don't remember the model number but it was around 10K grey) in 8" x 2. Both were good.

2 x 8" will be better IMHO if you are looking for kick but then loads of other things matter.

If i had to take a decision I would never buy a 10 or 8" if space and budget is not a problem. 12" is minimum what I would prefer specially after listening to 15" for a long time.

[Autophile]

Invinsible,

The alpine amplifier which you have got gives 250 Watts RMS 4 ohms in bridged mode. So the final impedance of the subwoofers should be 4 ohms. In which case you can use the following :

1. Single Subwoofer : 4ohms SVC / 2ohms DVC (coils wired in series)
2. Dual Subwoofers : 8 ohms SVC (wired in parallel) / 4 ohms DVC (coils wired in series and then subwoofers wired in parallel).

To get full use of the amplifier power you have you have to use either single subwoofer with 4ohms final load (250W) or two subwoofers with 2 ohms impedance wired with amplifier in stereo (125W each approx). If you parallel two 8 ohms subwoofers to get 4 ohms then each subwoofer will get less power due to 8 ohms impedance.

Two 8's will give you more bass than single 10" but also you can buy better quality 10" in the price of two 8".

To get fast accurate bass first you need good quality SQ driver. Then carefully tuned / designed well built box to complement the driver.

You will save more boot space with single 10" than 2 X 8".

[hydrashok]

Invinsible, two 8s will be faster than a single 10. But if it were me, I'd go for the single 10", simply because it goes lower, without compromising on speed or accuracy.

The extra benefit of two 8" subs over a single 10" may not be enough to go to the trouble of buying a good pair of 8" drivers, making two boxes, wiring them in the appropriate way, etc.. You can also dedicate all the amplification you have to the single 10" sub.

As JB said, you'd save more space with a single 10" sub too. I also echo what JB said about your being to get a very good 10" driver for the price of two 8" drivers.

I haven't listened to a pair of 8" subs yet, to be totally certain that the 10" sub will sound better though.

[navin]

Originally Posted by Autophile

You will save more boot space with single 10" than 2 X 8".

unless the 2x 8" are used isobarik.

[frankmehta]

abhishek. i think one single, good 12" would do the job for you. there is not too much of a space saving between a 10 and a 12, and a single 12 will be much smaller and more space saving than 2 8's.
15-16k is a great budget, but i would suggest you two very logical things.
your alpine does 250W bridged. my suggestion would be to bridge all 4 channels of your alpine and give your morel ovations about 250 W to each side. this will make them come alive, and make sure you utilize their full power (since they are rated @ 140W rms, and can easily handle up to 300W without a hiccup!)
for about 8-9k you can get a respectable 2 channel amp, or a monoblock, and the remaining 8k can be used to buy a respectable 12 SVC like the GzTW30T (or an ID CTX, provided you can source it.)
a sealed enclosure, if small, will require good amount of power, hence i recommend you get an amp that puts out about 300W RMS atleast.
there, you have a huge increment in your front stage, and the sub stage would match it!

[valhallen.282]

INVISIBLE the isobaric idea is something you can look into. the polk 8 inch units are excellent. but you can also look at say a JL 10 INCH. IMHO two 8 inch units are an excellent choice. It will be a little harder to tune them exactly and might get boomy. BUT it can be worked around. A 10inch seems to makes better practical sense. but acoustically i like crisper bass rather than lower. being lower in a lot of cars i have noticed here in blr does not mean that there is clarity to it.


Pardon me for contradicting anyone else but i like the idea of the twin 8's. I don't think there is much audio below 36hz as it is, so i don't see the point of actually wanting a sub that goes much lower. also the power required to drive a sub to those frequencies is higher and it needs a lot more of skill, time and effort. i would also like to point out that most of the frequencies higher than 36hz will mask off anything thats lower than that level. That is unless you listen to a lot of hip-hop. An 8inch unit will happily sing all day long at close to 32 even all day long. so my suggestion is the twin 8's. any day.

[Invinsible]

I agree that getting an enclosure for dual 8" subs will be bigger in size compared to the single 10" or 12". But its not much of a difference.

For example:
Incase of getting dual Polk Audio DB840DVC. The minimum sealed enclosure requirement is .35cu.ft. for each which makes it to around .70cu.ft for dual. Now in comparison to the Single 10" requires minimum .66 cu.ft.

As for the ID sub as per the manual over the net it say that normal size for single 8" DVC sub is around .35cu.ft and small size is .20 cu.ft. In comparison a Single 10" DVC requires normal size of .60 cu.ft, small size is .40 cu.ft. Which means incase i decide to for Dual 8" subs the size would go to .70 cu.ft and if small .40cu.ft.

Conclusion: What I understand from this is that I can have dual 8" sub with a marginal increase of the Internal size volume against that of a single 10" sub. Ofcourse the 12" enclosure size will be more than that of 10" too.
I do know understand by now that a single 10" sub will go lower. But how much low? compared to the dual 8" ? if there's marginal difference between both I have my first preference of dual 8".

250 RMS I feel should be good enough for subs having a limit of 300 RMS. i.e. 125RMS per sub where they have a limit of 150-170RMS. What's the take on this.

Reg the Sub:
How good the ID subs are in comparison to the IDQ?
How good the Polk Audio subs against the ID subs?

Price wise I suppose dual ID would cost me more than the POLK.
I guess polk is around 4.5K for each 8" sub against that of 8K for the ID.

Are there any other choice in 8" DVC sub?

Here's what I found on the crutchfield.com reg the sub wiring in 4 ohm. http://akamaipix.crutchfield.com/ca/...4-ohm_mono.jpg

[Autophile]

Originally Posted by navin

unless the 2x 8" are used isobarik.

I which case output will be less than single 10" in sealed or ported enclosure.

Tight & Crisp bass has more to do with the quality of the driver rather than the numbers.

As i have mentioned earlier one can buy better single driver in the cost of two drivers.

[panky12345]

Originally Posted by Autophile

To get fast accurate bass first you need good quality SQ driver. Then carefully tuned / designed well built box to complement the driver.

Very true.. A suggestion here would be ground zero Radioactive/Hydrogen series.

Why dont you contact a member LBM or B&T for the same?

[valhallen.282]

I beg your pardon but are you saying that there are drivers that are specifically for sq? when it comes to subs i do not believe that is something that applies. if it can actually come close to the claim on paper it can be put to the right application. from there on i think it is dependent on the application of the driver and the user/installer. I DON'T think you can classify drivers like this. could you be kind enough to explain what you mean by an SQ driver. if it is going to go OT I request you to please PM it.

[abhibh]

Originally Posted by valhallen.282

I beg your pardon but are you saying that there are drivers that are specifically for sq? when it comes to subs i do not believe that is something that applies. if it can actually come close to the claim on paper it can be put to the right application. from there on i think it is dependent on the application of the driver and the user/installer. I DON'T think you can classify drivers like this. could you be kind enough to explain what you mean by an SQ driver. if it is going to go OT I request you to please PM it.

I would differ with you here.

These are the features / qualities which i think there should be for a driver to be classified as a SQ driver:
- plays accurate through out the frequency range, with regard to how the music was recorded originally.
- no extra boominess.
- fast enough and should not overlap.

Though a lot of factors are responsible for making as SQ driver like Fs, Qts etc.

Now just from my experience I use a JBL sub (real VFM). But then its very boomy. No matter whether u put it in a sealed or ported box. Now i have used Blau sub in same sealed 1 cuft box and it sounds any day better than JBL. Every thing is same gains, box, car, amp, hu etc.

So it really depends how the driver is made. Some are made for SPL. Now you cant use the same SQ driver for SPL until and unless you tight the suspension and raise Fs values etc. Also most of the drivers which are used for SQ purposes are around 300-500 RMS.

P.S. I am not a guru and can be wrong.

[Autophile]

Originally Posted by valhallen.282

I beg your pardon but are you saying that there are drivers that are specifically for sq? when it comes to subs i do not believe that is something that applies. if it can actually come close to the claim on paper it can be put to the right application. from there on i think it is dependent on the application of the driver and the user/installer. I DON'T think you can classify drivers like this. could you be kind enough to explain what you mean by an SQ driver. if it is going to go OT I request you to please PM it.

Yes there are subwoofers designed for specific applications / user listening preference SQ, SQL, SPL. What one is capable of doing best the others can't do.

for example :

SQ Driver :

TS-W01RSII Pioneer Speakers & Subs - CarÂ*Entertainment

SPL Driver :

TS-W2501D4 Pioneer Speakers & Subs - CarÂ*Entertainment

Both the above mentioned drivers sound totally different tonaly and appeal to different listeners.

[valhallen.282]

I appreciate your response. the reason for asking was because if you tell me that xyz speaker is specifically for SPL i would believe you. but among others its purely a matter of personal preference and application. its like i like the neutrality of my blau's but to another it would be bland. therefore the question as to does such a thing as an SQ driver exist. i do not wish to hijack this thread any further. we shall try and continue this later. @INVISIBLE: apologies for the hijack. let me know what drivers you are getting. see if you can get the JL'S also. they are supposed to be very good. i haven't heard ID subs and shall refrain from commenting on them. but the DVC polks kick the behind just brilliant.

[Invinsible]

valhallen.282@ No issues with you hijacking it, as long as one can learn something out of that discussion. Somewhere I feel Autophile is right. There are SQ, SQL, SPL subs available from different makes. The way I see SQ subs are always restricted to 400RMS and produce much lower frequencies in a sealed or ported enclosure, incase you put them as free air they would sound like a Sony, JVC, Pioneer, Kenwood subs. SQL subs are restricted to 600-1000RMS. They go both low and loud. If one listen to them at lower volume they would sound low, and once cranks the volume they would go loud but would yet sound musical Something like, ID MAX, MOREL ULTIMO, JL AUDIO W7/W6, Diamond Audio, Digital Audio Subs. SPL subs are just made to win the competition and are best used in SPL enclosures which starts from 4.0 cu.ft.

But, In my case my main purpose of going for Dual 8" was that to have them in small enclosure, yet should sound musical, tight, and by going dual they would be loud. Now given a choice I would go for a 12". But I have noticed onething they all need the enclosure size of more than 1 cu.ft. Now for hatchback too, it's not much. But here's where you face a problem to have them when you are travelling out and you wanna put those bags, one does think of removing the box and keeping it back home. And I never enjoy my music that way. My Idea was to get dual 8" in an enclosure of around .5 cu.ft. for both, where the enclosure would be designed in such (since being .5cu.ft) a way that it wouldn't obstruct me from stuffing those bags in there. and still have both, the baggage and bass. So, is it worth having dual 8" setup against the single 10"? Will it be as good as single 10" or better, incase the drivers are the same ?

What I wanna know is how much of difference will it be between dual 8" and single 10" in terms of tight musical bass is concerned and clean of course given the fact that they would both have identical requirement of enclosure, .5 to .6 cu.ft. The advantage with dual 8" will be is it would have a surface area of i suppose 15" sub compared to the single 10". Which also mean it would move more air in an hatchback than a single 10 would.

As for the sub: I initially thought of getting a shallow mount sub, but can't find a good one. So, thought of getting an ID, POLK, Dual 8" subs.
Does anyone know of a good shallow mount subs?
Also, called Kumar Agencies and it seems they don't have 8" DVC 4 ohm DB series sub with them, instead got an offer for POLK MOMO 8" DVC. How good are they ?

Autophile@ How good are ID series compared to IDQ series?