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Best drivers for subwoofer?

Prize78

Well-known Member
Ive used AE and love them!

Ive not used ay of the others, but there are plenty of good ones out there.

Pretty much all in the states aren't they??!!
 

Member 639844

Former Advertiser
A lot are. I'm ordering 4 AE drivers next weekend though with sammy the squid. If anyone would like to come in on the order then feel free to let me know.
 

Member 639844

Former Advertiser
It really depends what your after. What is it your looking for. IB's need to use multiple drivers, and you need the available space to install one. Do you have the available space for an IB.

Believers in IB will tell you its the best bass you can get, but not having ever heard one I cant say myself, although all those people cant be wrong if you ask me.

You say a reflex system, but what exactly is the kind of sub you want to build. There are a multitude of designs all with their own strengths and weaknesses and all are varying degrees of difficulty to make.

If you want to pick a sub design, then this link may help:

Audio Innovation - by Dan Marx www.danmarx.org

If you want to look into IB's, then check out the cult of IB website.
 
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Prize78

Well-known Member
A lot are. I'm ordering 4 AE drivers next weekend though with sammy the squid. If anyone would like to come in on the order then feel free to let me know.

I'd love to get in on the act mate, but funds are too tight at the moment. I reckon it's something i'm going to start saving my pennies for though! :thumbsup:
 

HiFiRuss71

Distinguished Member
Dan, in the context of this forum and indeed most of the world, an IB is simply a sealed cabinet. The Cults hijacking of the term has somewhat distorted this reality. I believe Timmy10 was using the term in it's traditional sense and referring to IBs like those owned by you and I.

Russell
 
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Member 639844

Former Advertiser
I'd love to get in on the act mate, but funds are too tight at the moment. I reckon it's something i'm going to start saving my pennies for though! :thumbsup:
2 of those drivers are for Sam, and 2 are for me. Currently only one of those is spoken for and the other one will be looking for a good home. I have got it to play with sub designs and nothing else. If you want it at any point then drop me a PM and I will either build something for you, or sell you the driver via the classifieds.

I will be ordering more in the future (the bug has got me :D), so either way there is something that can be done for you at some point.
 

Member 639844

Former Advertiser
Dan, in the context of this forum and indeed most of the world, an IB is simply a sealed cabinet. The Cults hijacking of the term has somewhat distorted this reality. I believe Timmy10 was using the term in it's traditional sense and referring to IBs like those owned by you and I.

Russell
I can see were your coming from. In line with your comment, and coming back to the title of this thread, an IB driver is just a driver like any other, it just has IB in its name. Any drivers can be used in an IB, but the IB specific ones are generally altered to focus on their use in that they are cheaper. Thy loose everything not required in the more substantial drivers to keep costs down given that IB's need multiple drivers, with 4 being the norm.

To the OP, what is it your trying to design, what size and budget do you have, what are your aims and goals, and how much help do you need. We can better focus our advice with that info.
 

Member 645097

Standard Member
Hey guys, thanks for all the posts! When I was talking about I.B. I was thinking in the traditional sense of a sealed enclosure, ie: "infinate" baffle. I think this, along with reflex, are the two main options available to myself. I have built loads of reflex cabinets over time, and have good knowledge of them. I think, however I.B, or sealed generally yields a smaller cabinet. I would like to give the true infinate baffle a go, by porting the system through a wall or ceiling, however having just decorated my listening room, am reluctant to start tearing things up, given my lack of knowledge of this type of system. Additionally my budget will only allow me to stretch to a single driver.

I have been looking at Acoustic Elegance, and the SEAS prestige range of woofers. Again, having used SEAS before I like this idea and know how efficient they can be with regards to low-end response. Another alternative is the Precision Devices range of drivers.

In terms of charicteristic sound, I am trying to achieve a fast-paced response that subtly adds to my existing set up (using SEAS T18 coaxial - XP cone for main speakers) I like the extra layers of detail a sub can add to a system and would like to retain this in my finalised design.

Any further ideas?

Thanks.

T
 

Member 645097

Standard Member
In addition to my previous post, I believe its the Mechanical and Electrical Q values of the driver which suit it to be used in a specific cabinet design. Q factors are values which designate the degree of mechanical and electrical resonance in the given system, meaning certain types of enclosure yield better performance and offer increased control.

Anyone have any further thoughts on this one?

Thanks again,

T
 

Ashmanuk

Well-known Member
In addition to my previous post, I believe its the Mechanical and Electrical Q values of the driver which suit it to be used in a specific cabinet design. Q factors are values which designate the degree of mechanical and electrical resonance in the given system, meaning certain types of enclosure yield better performance and offer increased control.

Anyone have any further thoughts on this one?

Thanks again,

T

And there's me thinking you just build a box put a hole in it and put the driver in :eek: Mmmmm there's more to this then meet's the eye ;)
 

micb3rd

Active Member
In addition to my previous post, I believe its the Mechanical and Electrical Q values of the driver which suit it to be used in a specific cabinet design. Q factors are values which designate the degree of mechanical and electrical resonance in the given system, meaning certain types of enclosure yield better performance and offer increased control.

Anyone have any further thoughts on this one?

Thanks again,

T

Yes subwoofer drivers are designed with an idea on what what to be achieved.

You can design the motor, T&S Params and the compliance so it will favor sealed, sealed and ported or just ported.

Suspension Compliance is the stiffness or "mushyness" of the suspension (spider and surround).

This suspension compliance damps the driver motion otherwise it would peak/ring and fly around a lot at fs.

So as you get a stiffer suspension compliance you get a raising of Q as you get looser compliance it reduces in Q.

This is why different speakers (with different compliances) like different sized boxes as you use the airsping compliance in the box to act against the drivers compliance to give a final driver compliance.

Air in a box is compliant so a small air space stiffens against the compliance of the driver, a large airspace dampens the compliance of the driver.

This is why final Qtc is calculated by airspring in the enclosure acting with or against the drivers Qts. This is why even when you go massive sealed or IB the Qts is the minimum Qtc you can achive as the large airsping compliance does not damp the drivers compliance any more, so the raw drivers suspension compliance is the minimum possible value.
 

HiFiRuss71

Distinguished Member
Was thinking of using the design subwoofer from SEAS, anyone have a oppinion about this?

T
Seas don't make any sub-bass drivers worthy of too much note IMHO. Even the H1209-08 L26RFX/P, which is only a 10" driver, lists it's linear travel as 14mm peak to peak; 7mm of Xmax then. Not very much and seems to be much more of a bass driver for a three-way speaker as a result.

Compare that to the Peerless XXLS-10 at 12.5mm Xmax. That's shifting nearly double the volume of air within the range of linear travel and sub-bass needs to shift air is nothing else. The small(ish) voice coil helps keep inductance low and therefore maintains an extended top end reponse, which inturns helps keep distortion low in the upper bass.

The Acoustic Elegance drivers major in this respect, but their greater throws with larger voice coils mean they have to engineer in a few expensive features to gain the extra bottom end output, whilst mainting the upper bass response. My AV15-X drivers are good to nearly 1kHz before the response starts to tail off, followed by the first major cone break-up mode.

All that said, I think you need to decide your maximum cabinet size first and then buy the driver that gets the best response with that volume. There is this idea that you can stuff pretty much any driver in any box and then sort out the response with lots of power and EQ, which to a point is true, but they're not the most musical sounding designs.

Russell
 

Nimby

Distinguished Member
In defence of The Cult of the Infinitely Baffled and the True Infinite Baffle Subwoofer: :)

Russell has obviously become confused by all his recent cabinetry glue sniffing. :devil: While I am much older and wiser, and probably borderline senile, I can still remember the first "infinite baffle loudpeakers" from first hand experience.

True Infinite Baffle subwoofers are very large closed boxes. Usually they are so large that they don't even need to be well sealed. Room sized boxes of 600 cubic feet, or 17 cubic metres, are the normal minimum volume required. Their (enormous) advantage is that you can happily live a completely normal life right inside the enclosure. No boxes are needed in the AV room and no sound absorption in the enclosure.

The ideal True IB subwoofer uses the entire Earth's atmosphere as its enclosure. Because there is really no need for an IB to have any box at all. It is merely a convenience in a domestic setting to stop the opposite phase, rear (rarefaction) waves from reaching and cancelling the front (positive) pressure waves at the edge of the (theoretically infinite) baffle. Using a room for the enclosure/cabinet contains the bass emanating from the rear of the driver/loudspeaker unit. Both front and rear of the driver cones reproduce sound in equal quantity but of opposite phase.

Unfortunately the term "infinite baffle" was hijacked by the loudspeaker industry in a desperate bid to sell dirt cheap and simple, sealed boxes at very high retail prices to a gullible and completely ignorant general public. A public who were just beginning to discover they were not really affluent enough to afford the new High Fidelity equipment following years of rationing after the Second World War. This was prior to teenagers receiving a living wage. So this potentially vast market had yet to be tapped.

Giving these new, little, sealed boxes a pseudo-scientific name was supposed to overcame their complete lack of bass and desperate shortage of Xmax to go loud and low simultaneously. Should I also mention their horribly coloured sound quality? I know, because I was there. :)

Ironically, the new little sealed boxes required a completely different type of loudspeaker/driver to the former reflex and open-backed, resistive cabinets commonly used up to this time. Loudspeakers in the home were normally used in open backed radios and radiograms with a perforated hardboard back to protect the public from lethal voltages. Pioneering High Fidelity Enthusiasts built brick reflex cabinets or concrete exponential horns in the corners of their drawing rooms.

Unfortunately the high compression of the air inside the new small sealed box, by inward cone movements, forced up the natural resonant frequency of the cone on its suspension. This robbed the little sealed boxes of the deep bass enjoyed by all those who used the reflex (ported) principle. Something had to be done!

One could overcome this lack of bass with a much heavier cone or much floppier suspension. Or both. Prior to this, loudspeaker units had corrugated rims to their cones to act as suspension for the bare few millimetres of movement they could manage. The new, small, sealed boxes needed much greater cone movement if they were to reproduce useful bass. So the roll surround suspension was born. This half round, foam edge allowed the cone to move much further. Though this also required completely new thinking about voice coil and motor design. The new loudspeaker units/drivers began to evolve away from the conservative designs of the past into the large, floppy units we see today. Now only PA drivers tend to follow the Old Ways of corrugated surrounds, small Xmax and high Fs.

Competitive SPL drag racing and car audio have given driver evolution even greater impetus towards cheap, large, fairly floppy drivers with tremendous displacement thanks to long, linear cone movement. (Xmax = one way useful travel) Without all of these incremental developments, subwoofers, as we know them today, would not exist.

The True Infinite Baffle Subwoofer uses several, large, floppy drivers with very low self resonance (Fs below 20Hz) and completely avoids loading the cones with back pressure to provide a smooth, linear output to below 10Hz. IB's are renowned for their low distortion and lack of compression. They have become the subwoofer of choice for those who have a suitable spare room, attic or cellar off the AV room. Since True IB subwoofers are so affordable, relative to many commercial subwoofers, price does not usually enter into their choice. Very few commercial subwoofers can compete with a True Infinite Baffle. None can compete at anywhere near the installed price of a common four x 15" driver, True Infinite Baffle Subwoofer. :)
 
B

basshead

Guest
Was wondering if anyone has any advise regarding the best drive units to use for a DIY subwoofer build. Been looking at Seas Prestige/Excel as I have used these drivers before, and Acoustic Elegance.

Thanks,

T

Peerless,Dayton Titanic, Ciare 12.00 SW (1000w rms 12 inch with 4 inch coil and 11.5mm xmax), Eminence Lab 12 (500w rms, 2.5 inch coil,13mm xmax).
 

Member 645097

Standard Member
Ok, so I should be looking for maximum Xmax in a driver, is this more important than frequency response / efficiency? I suppose I would like to keep the cabinet small, but am prepaired to compromise this in order to increase output. Maybe I.B. would be a better option? I can build a baffle into a wall without problems, as my room has void spaces in the walls, which go to outside.

The seas driver I was considering was the L26ROY, and can be found at http://www.seas.no/index.php?option=com_content&task=view&id=238&Itemid=223

Thanks again!
 
B

basshead

Guest
Ok, so I should be looking for maximum Xmax in a driver, is this more important than frequency response / efficiency? I suppose I would like to keep the cabinet small, but am prepaired to compromise this in order to increase output. Maybe I.B. would be a better option? I can build a baffle into a wall without problems, as my room has void spaces in the walls, which go to outside.

The seas driver I was considering was the L26ROY, and can be found at THE ART OF SOUND PERFECTION BY SEAS - D1001-04 L26ROY

Thanks again!

Xmax is the when the coil stays in the magnetic gap and stays linear.

Xmech is the maximum excursion limit before damage to the driver occurs.

When a driver gets past it's xmax it won't be linear as the motor system(magnet and top and back plate) won't have as much control over it and it can reach it's xmech much easier then.
Plus whilst the driver is within it's xmax it sounds clean, when it gets past it's xmax it starts to sound unclean.

Efficiency is how loud it goes at the given input of 1w at 1m. And +3db sounds twice as loud.
So a driver with a sensitivity of say 89db at 1w, 1m, would be twice as loud as a driver with a sensitivity of say 86db at 1w,1m.
If both drivers were driven by the same power input.

Frequency response without a graph can be pretty meaningless. As it can drop off pretty sharply sometimes.
Although a driver can say it goes to say 30hz that might be at -30db.
The resonance frequency of the driver (fs) is much more useful if there's no graph to see where it rolls off at.

More info on TS parameters of drivers here:
Speakerplans.com
 

micb3rd

Active Member
Xmax is the when the coil stays in the magnetic gap and stays linear.

Xmech is the maximum excursion limit before damage to the driver occurs.

When a driver gets past it's xmax it won't be linear as the motor system(magnet and top and back plate) won't have as much control over it and it can reach it's xmech much easier then.
Plus whilst the driver is within it's xmax it sounds clean, when it gets past it's xmax it starts to sound unclean.

Efficiency is how loud it goes at the given input of 1w at 1m. And +3db sounds twice as loud.
So a driver with a sensitivity of say 89db at 1w, 1m, would be twice as loud as a driver with a sensitivity of say 86db at 1w,1m.
If both drivers were driven by the same power input.


Frequency response without a graph can be pretty meaningless. As it can drop off pretty sharply sometimes.
Although a driver can say it goes to say 30hz that might be at -30db.
The resonance frequency of the driver (fs) is much more useful if there's no graph to see where it rolls off at.

More info on TS parameters of drivers here:
Speakerplans.com

Don't mix driver Sensitivity with Efficiency, they are different.

You can measure a driver Sensitivity value in so many ways it is not comparable between manufactures.

Also Sensitivity measurment has little to no impact on real life subwofoer output as the enclosure will dominate this.

As you approch 1.5 octaves above the box Fb the enclosure becomes the number 1 factor in Efficency. Hoffmans Iron Law of box size, frequnecy responce and efficency comes into play and you can pick 2 factors but not not have all 3 due to the laws of phyics.

Yes subwoofer drivers are designed with a passband (a frequency band they play best at) that they will play hecne why PA speakers and subwoofers are different.

You match the woofer passband with the enclosures passband and you get you final system responce (before room interaction).

To play outside of your box/drivers passband you need more input power to compensate as you are outside of where the system is Efficient.
 
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