1st Sub post!!! What would suit my room?

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Hi all you mega bass heads!!!

Ok I like Bass too. 😀

So the story goes:

Most of my amateur ventures into loudspeakers to date have been 2 ways, using 5-6" woofers, and typically a dome of some sort (recently got a little into ribbon tweeters), so I dont have sub like levels of bass.

I have enough bass considering the small size of the woofers. What annoys me about woofers of this size, is that no matter how low their Fs is, radiating surface area/displacement is far more representative of bass.

Damn! horrible realisation. The way to go is maybe a 3-way.


So i begin to search for 10-12" sub/woofers, to build as small as feasible, and to go as low as feasible. I look at a few Hifi Subwoofers, Visaton TIW200XS, TIW250XS, a couple of Morels.

Second realisation: when i compared the visaton TIW200XS and the AL200 for example, then there isnt much between them. The 'sub' has more Xmax, way heavier cone and less BW to play with, 3 less dB, costs more. All in all, I may as well just use the AL200 hifi woofer.

The thing is, I dont like the look of a 100g+ cone on a 10" driver..... with Xmax +/-12mm....more like an earthquake generator...only for HT subsonic FX.

So I had another look, and came across this Mivoc AWX184 18" woofer which according to the sites recommended cabs, does a sealed cab -3dB @ 70Hz, in 50 litres....:

http://www.lautsprechershop.de/pdf/mivoc/awx184.pdf

What do you seasoned Sub folks think about this driver?

I think with the 5mm xmax, maybe it would be a good candidate for Linkwitz type EQ in the small closed volume.

Many thanks in advance! 😀
 
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Here come the usual questions...

Room size?
Placement options?
How low?
How loud?
Where is the power coming from?
Can you use active crossovers?
Budget?
Maximum cabinet size?

You say as low as feasible, but I've tried throwing power at a pair of the 6.5" TB subs in sealed cabinets. ~13dB of gain at 20Hz. The result was 20Hz extension, but excursion went to ~2mm p/p at <80dB nearfield.

Chris
 
my room is 5m square L shaped by 4m width, so its perhaps an awkward room. I use 84dB 2ways driven by a Cambridge A1, I typically listen at half volume at my loudest. the idea of a sub around 24 inch pair of cubes or coffin tv stand sub would suit i guess. The mivoc just appealed for sheer displacement, and the relatively small boxes reqd. Given their 98 dB i would also have spl to spare or 'waste' as fits.
I dont currently use active, but an active or line level crossover and another amp, is probably the direction i would like to go, but probably passive initially.
 
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I'd strongly recommend you go for active crossovers. A 4th order LR is <£10 to assemble, though finding a nice box is more of a challenge.

Slightly confused about " the idea of a sub around 24 inch pair of cubes" - are you looking for two subwoofers?

The displacement offered by the 18" would certainly mean impressive bass, though I'd expect it to be massively overkill for your room. If you want to go silly, then don't let me stop you. Make sure you re-inforce your home though (yes, I'm serious).

Chris
 
Chris, perhaps a slightly silly idea of mine, but it was borne from comparing some 8 and 10 inch subs with larger woofers. The TIW200XS for example and IIRC goes flat to around 40hz in 50 litres vented, not THAT great IMO. Abysmal SPL. Compare that to the AL200, which gives a similar response in the same volume, but mms is HALF.

The TIW250XS is a little better in extension but requires more like 80litre

The 18 incher works in 50 litres sealed Qb of 0.8, and was considering a linkwitz EQ and or series cap to lower f3 further. All in all, the choice or lack thereof in suitable woofers, is frustrating. Ideally an 8 or 10 incher vented and flat to 30hz would be nice, im just struggling to find it!

Since my current mains have an f3 of 40-45hz im not sure these small subs offer anything that a good woofer of the same size can. Except heavy cones poor efficiency, and a larger dent in my wallet.
 
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Hi,

A suggestion of a IMO very 'musical' sub using the Visaton AL200 driver:

b🙂
 

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Very nice Bjorno!

I use Hornresp a little, but im no expert. Can you tell me why the flare profile is set on 'Parabolic' ?

I guess it wouldnt make a difference since S1 and S2 etc are the same area anyway. So basically a TL?

But at the same time, it looks a little like a tapped horn.... Im a little confused. lol even like a Tabac for Sub-bass 😀
 
haha thanks chris but £150 peerless/scan/seas mega excursion lead coned subs are exactly what im trying to avoid. I will have a mess with them in WinISD before i write them off completly. At less than half the price, the AL200 midwoofer in perhaps a bipole or isobaric sub using 2 drivers could be another avenue i could persue. 30hz f3 in 30litres? big BIG grin if i manage that!
 
i got sidetracked again Chris. I understand your comments about the cone weight, and id agree. Its not solely the heavy cone which puts me off, but the sub 0.3 Qts that seems to go with it. The trouble I have is that at least with the visaton subs, that the extension isnt any better than the woofers. The excusion capability and ultimate volume is superior, but Vb and F3 are similar (AL200 vs TIW200XS). That being said the Seas L26RX*something* looks to me like a very good compromise. I am aiming for a Vb between 50 and 80 litres, max 100, but itd have to be extra special for me to sacrifice that much space.
 
haha you read my mind, i actually looked at that peerless as it was cheap, and forgot the model number! Both that driver and the L26RX thingy look like the favourites at the moment. I looked at some of the 'proper' subs, and had a mini epiphany. With such longer throw and 200g cones like the SBs, its a balance of increased mech damping and magnetic damping. So its a compromised balance between Qts and Cms. As always i guess, but to a greater degree in these subs. A Qts of 0.25 is a deal breaker, even if the Fs is 20 Hz. 50mm xmax is crazy though, unfortunately id probably just spend my time watching them with a 20hz sine pumping out!
 
haha you read my mind, i actually looked at that peerless as it was cheap, and forgot the model number! Both that driver and the L26RX thingy look like the favourites at the moment. I looked at some of the 'proper' subs, and had a mini epiphany. With such longer throw and 200g cones like the SBs, its a balance of increased mech damping and magnetic damping. So its a compromised balance between Qts and Cms. As always i guess, but to a greater degree in these subs. A Qts of 0.25 is a deal breaker, even if the Fs is 20 Hz. 50mm xmax is crazy though, unfortunately id probably just spend my time watching them with a 20hz sine pumping out!

I see no reason such a low Qts is a deal-breaker - it just means it'll go into a really small ported (or PR) box. Could be useful, but running a couple of simulations to see what's expected is better than guesswork.
You might be wise to go for an EBS alignment (only with ported cabinets), or be prepared to eq for the result of room gain and a response that goes flat to LF.
I found that porting for 40Hz for my TBs to be too much, and had to add a handful of stuffing to the ports.

Chris
 
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