# Woofing through the ages



## djeickme (Dec 19, 2007)

I wonder if any one has any experience or opinions (as we all know the two are not the same thing) with changes in subwoofers over the relatively bried history of the beast. It seems to me that much of the "progress" in subwoofers has been related to the never ending quest to make them smaller and more room friendly as opposed to making them better performers. The top of the line subwoofers in the early days of home theatre (let's say the mid to late eighties) were huge beasts like the ULD 18 and the Snell SUB 1800. Now the top model from a brand like Velodyne is probably a third smaller than its ancestor. Does it reach much lower? play much louder? My only experience is comparing an old ULD 12 to a current production Paradigm Servo 15. Now this comparison should be taken with a grain of salt as they weren't in the same room but the same program material and same partnering equipment were used but I think it is still informative. The new production Servo 15 is a bit smaller than the older 12 inch. On movies the Servo 15 may be a bit louder and lower but you can really only tell on the most extreme material. It seems to me that the "discount" brands like HSU and SVS have simply stuck to the formula that was used 15 or 20 years ago. That formula seems to me to be build a great big box and stuff it with a reasonably large driver (let's say 12-14 inches with a one or two inch peak to peak excursion) and a reasonably powerful amp (let's say three or four hundred watts). They seems to be able to get performance that is spitting distance from the "statement" products like the JLAudio F113 or a Velodyne DD18 for 33% to 50% of the cost. I bet if we compared some of the old products like the ULD 18 or some of the THX models from M&K or even some of the old passive models like the SUB 1800 to the modern statement products and there discount competitors, I bet we would find the differences very small. I guess it all boils down to how much space you want to devote to your hobby.


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## atledreier (Mar 2, 2007)

It's all about volume. I have yet to listen to a small sub that could compete with a proper, big sub. It's physics. Simple, in my book.


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## tonyvdb (Sep 5, 2007)

Size defiantly matters particularly with good companies like SVS or HSV but its not always about the size of the driver its also about the box or tube design baffles and bracing as well as how the enclosure is ported or sealed.
I have an A/D/S MS3 that is now almost 12 years old its only a 10" long excursion but has a great frequency response at 20 to 100Hz at 106db (yes it really does 20Hz and lower) it truly is as good as it looks. Its both a ported and a sealed unit (bandpass) and I am always amazed at how low it can go as my room is very large (15'x35') and it has no trouble filling it. For the time it was built when Home theater was just starting thats very impressive.


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## ISLAND1000 (May 2, 2007)

Technology, materials, and electronics have all had an affect on todays audio equipment. Speakers as well as amplifiers have "improved" in the last twenty years. Today's speakers play lower (and higher) with less distortion than those of yesterday. Yesterday's amplifiers went to about 70 watts with tubes. Today's amplifiers go to a thousand watts and more with all sorts of output devices we never heard of twenty years ago.


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## jr1414 (Nov 28, 2007)

It's interesting to see the trend from large boxes to smaller, although it's pretty well proven that larger enclosures and careful tuning yields much better efficiency. I think what the poster was referring to is that we've utilized technology to shrink the envelope, rather than increase overall performance. 

Amps, drivers, etc. are capable of handling much, much more power and heat dissipation, which has enabled mfg's to get comparable performance to a larger enclosure with EQ-ing. But the question is, would there be a larger benefit in using the newer technology in a larger enclosure, tuned properly and not requiring massive EQ-ing to make up for the inefficiencies of the smaller enclosure?


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## ISLAND1000 (May 2, 2007)

jr1414 said:


> But the question is, would there be a larger benefit in using the newer technology in a larger enclosure, tuned properly and not requiring massive EQ-ing to make up for the inefficiencies of the smaller enclosure?


Simple answer, NO. Massive EQ-ing or minimal EQ-ing has been made available because of that new technology. I say overall, . . . . EQ and drivers with new magnet design, new surround design and material, new spiders, and new cone material used in small subwoofers bests no EQ and drivers in big boxes/tubes, LLTs, or IBs.


:whistling:


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## jr1414 (Nov 28, 2007)

Wouldn't you agree that the additional EQ-ing used to make up for the natural response of the smaller boxes creates a huge amount of heat and requires much more additional power than if it were utilized in a more efficient enclosure?

I'm not saying that there is not a market for smaller enclosures, there most definitely is. If my wife was a little less accepting of my hobby, I'd be looking at a smaller box right now. Just that if you could utilize the technology more efficiently it should result in either better performance or improved reliability. Heat and wasted power are the enemy, are they not?


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## ISLAND1000 (May 2, 2007)

jr1414 said:


> Heat and wasted power are the enemy, are they not?


Yes they are, especially in today's "Green" world. However, we get those same energy savings (as a result of) using new technology. Todays new D,H,I , etc. class amplifiers operate using much less electricity to produce the same volume of sound in dbs. We can NOW afford to use more power to be able to use EQ and still avoid creating heat and wasted power.


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## jr1414 (Nov 28, 2007)

I disagree. If it can be done more efficiently, why not? Adding say a +6db boost at 20 Hz can result in a multiple higher power requirement. All that power and energy takes it's toll over time. 

Think of it like a fuel injector in a car. It may be capable of providing a maximum fuel flow of X, but that would require the injector to work at 100% duty cycle. The car may only require a flow of X/2, so the injector, although it's capable of more, operates at 50% duty cycle. Studies have shown that the injector working at a lower duty cycle lasts multiples of times longer (5-6 times) than the injector working at the higher duty cycle. 

It may not be as drastic as 5-6 times, but there should be some gain in total life cycle of the amp, driver, etc in a more efficient enclosure. I'm not saying it's not possible to accomplish more in a smaller package today, or that it may even be more efficient than tube amps for existance. But if we can lower the requirements even more with the enclosure, there should be more headroom to play with, less introduced artifacts (processing) and longer life spans of the components.


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## warpdrive (May 6, 2007)

I think that this is just the natural evolution. Thanks to high efficiency digital amps and improvements in drivers and the materials, you can design a smaller sub that rivals some of the bigger ones from yesteryear. Most people don't want a refrigerator sized box in the room so manufacturers are just catering to the natural tendency to design smaller boxes. With transportation costs high now, it's just more cost effective to have a product line that takes up less space.

SVS, eD, Hsu, Epik are catering to the Internet Savvy, High Value Buyer that wants all out performance without regard to box size. They are filling the niche left by the mainstream sub makers.


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## ISLAND1000 (May 2, 2007)

warpdrive said:


> SVS, eD, Hsu, Epik are catering to the Internet Savvy, High Value Buyer that wants all out performance without regard to box size. They are filling the niche left by the mainstream sub makers.


These subs take advantage of all the latest advances in technology, materials, and techniques and even the above boxes ARE smaller than 20 years ago. I built Karlson, Bass Reflex, EV folded horns, RCA theater speakers, and James Lansing clones that were 12 to 20 cubic feet.
There's no need to build enclosures like they did 20 years ago unless you have a particular driver or drivers that benefit from LLT or IB configuration and you wanna scare the family with 6 kids in the next block!
Twenty years ago there WAS no discussion about reproducing 10HZ . . . . there was no driver that could do that at noticeable volumes.


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## djeickme (Dec 19, 2007)

I don't think that one approach is (ie large versus small) is necessarily better than another. It is a matter of recognizing what is important to you and them choosing product accordingly. Let's say you live in a small appartment in a large urban centre. For you maximum output is a non-issue because of your neighbours. Getting flat output to below 30 hz is also likely a non-issue because your room is likely too small to naturally support frequencies in that range. For you the size of the sub and its ability to match with your main speakers is of utmost importance. For you the Sunfire ultra-compact subs would be a great choice. For someone else (like me perhaps), a large sub would be a better choice (I have a large house with a reasonably sized acoustically treated room, and no neighbours to complain). My main considerations are getting the flattest output to at least 20 hz and output at THX reference levels. I have the space to do that with large boxes. I think that in general (both in audio and in life) we are trying to pidgeon hole people into too few categories. I think that having a variety of products on the market from microsubs (like the Sunfire) to highly engineered mid-sized subs (like JL Audio and the Velodyne DD18) to large simple boxes (like HSU, SVS and the numerous DIY solutions on the market) means that each person can get what they want and need (assuming they are willing to realistically assess those wants and needs).

Getting back to the original topic, I think it is possible to say that the changes in the subwoofer market are simply progress, but the question is really "Is progress always a good thing?". The sound that I am getting out of my mono system based on an old Goodham driver with a University horn tweeter in a Karlson enclosure let's me get far closer to the performer in many ways (midrange purity, timing, and emotional impact) than my stereo system that clearly measures better and has a much more extended frequency response. In this case progress is just different as opposed to being better. If you are looking for a smaller subwoofer box, I clearly concede that there has been much progress in the last 20 years. If you are simply listening to music or movies and not focusing on specs and technological one-upmanship I am less convinced that we have progressed very far.

Just one guys not so humble (how humble can it really be if I have posted it on an internet forum) opinion
Dan


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## bobgpsr (Apr 20, 2006)

Do not smaller rooms help to get very low freqs? Since room gain increases the lower you go?


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## ISLAND1000 (May 2, 2007)

bobgpsr said:


> Do not smaller rooms help to get very low freqs? Since room gain increases the lower you go?


They DO . . . . not?
But there is a point of diminishing return.
I put my entire HT system and a recliner in a small closet to "take advantage of the room gain". That was really good for bass but it sucked for having any visitors.


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## aceinc (Oct 24, 2006)

I come down on the side of, if the new technology is coupled with the maximally efficient design the sound has to be better. This assumes that you have the space, neighbors, spouse and fortitude to enjoy it :thud:

My reasoning goes like this;

Assume that you acquire a superior driver(s), design a no compromise enclosure and power it with an amplifier that is double or more of the rated capability of the drivers, place it in an optimal location in the room. The coupling of the driver to the enclosure will undoubtedly provide maximal efficiency. Generally one of the rules in speaker design is that the more power required to attain a specific nominal SPL the greater distortion, and the lower the dynamic headroom.

The distortion comes from everywhere, the electrical outlet, amplifier, overheated voice coils etc. When you add in the squaring of power to yield 3 db of SPL you can see that the headroom disappears rapidly as well.

If you use the same driver with the same or different electronics and compromise the enclosure, additional power will be required to acheive similar spl. At a minimum the dynamic headroom will be reduced, I also believe that distortion will be increased.

I guess what I am trying to say is that I believe if you couple "old school" with new technology you can get better results than either one separately. By way of example, I give you this; http://www.decware.com/newsite/mainmenu.htm?/ImperialSO.htm&intro


Paul


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## Guest (Feb 1, 2008)

:bigsmile:Well, i havent had to much experience with WOOFING through the ages lol, i do realize that i prefer (so far) my HPM-100 connected to a technics su-7700 over anything i have had by far! I mean wow, these speakers give so much bass that is rich and deep, and the best part is the cones aren't rotted out, because they were made with some good material lol. I just love these speakers compared to today's, although obviously a pair of 2000$ tower speakers would definetely provide more better sound, but these speakers are over 30 years old, and it seems i use them for all of what i need. Down side, they are heavy, and the amp doesnt have dolby surround ect, but i think back in the day, they new what they were doing with alot of those products.


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## thxgoon (Feb 23, 2007)

Just curious if anyone here remembers when the Sunfire True Sub first came out. I think I still have the Stereo Review magazine where the editor was looking for a giant 18" hidden somewhere. Talk about a new beginning.


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## ISLAND1000 (May 2, 2007)

Wasn't that another creation of Bob Carver's? What a guy! I would say (he) more than any one product development has changed the shape, sound , and size of todays electronics.


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## drdoan (Aug 30, 2006)

Speaking of Carver, when I was a bench tech years ago, I would have to measure total output and THD on any amp we fixed, along with a few other tests, so we could verify that the equipment was up to snuff. I remember testing my first Carver amp. It tested way better than the specs called for. I can even remember how the amp looked with the cover off! Didn't he get the class D amp idea going? Dennis


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## Ricci (May 23, 2007)

I still remember when Sunfire came out too. The subs were interesting but it was all the write ups on the Tracking Down Converter power supply(I think that's what he called it) in the Sunfire amps that was the real news.


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## thxgoon (Feb 23, 2007)

Ya I remember reading the white paper about the tracking down converter and a concept known as 'back emf' which allowed an amp with about 1000 watts of real power to put out 2700 watts with much less heat dissipated in the driver and amp. Can't remember how it all works anymore. I wonder what class the sunfire amps are considered. Really advanced stuff in the day...


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## ISLAND1000 (May 2, 2007)

It may be that the "tracking down converter" power supply amplifier, after it was licensed to others, became class 'D'. But don't hold me to it.


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## drdoan (Aug 30, 2006)

that is my understanding, too. It is now called class D amplification. It has something to do with the "rail" voltage being made to track the output within say 5 volts, so that the 2 voltages parallel track each other. I am not an expert on that. Dennis


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## tonyvdb (Sep 5, 2007)

Even Bob Carvers Sonic Hologram and his Magnetic field amplification was way ahead of its time. My Carver Receiver was just amazing.


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## bobgpsr (Apr 20, 2006)

drdoan said:


> that is my understanding, too. It is now called class D amplification. It has something to do with the "rail" voltage being made to track the output within say 5 volts, so that the 2 voltages parallel track each other. I am not an expert on that. Dennis


Not really anything about class D switching amplifiers (see diagram of one).

in regards to the neat idea of a tracking down converter power supply used for a subwoofer amp.

So Parts Express calls what they sell as "class G" amplifier which has a class AB output stage with the patented tracking down converter power supply.











wiki said:


> There are a variety of amplifier designs that couple a class AB output stage with other more efficient techniques to achieve a higher efficiency with low distortion. These designs are common in large audio amplifiers, for instance, since the heatsinks and power transformers would be prohibitively large (and costly) without the increase in efficiency. The terms "class G" and "class H" are used interchangeably to refer to different designs, varying in definition from one manufacturer or paper to another.
> 
> Class G amplifiers are a more efficient version of class AB amplifiers, which use "rail switching" to decrease power consumption and increase efficiency. The amplifier has several power rails at different voltages, and switches between rails as the signal output approaches each. Thus the amp increases efficiency by reducing the wasted power at the output transistors.


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## ISLAND1000 (May 2, 2007)

tonyvdb said:


> Even Bob Carvers Sonic Hologram and his Magnetic field amplification was way ahead of its time. My Carver Receiver was just amazing.


But Tony, what happened? You now show a Onkyo TX SR805 and a YAMAHA RX-V995 in your systems. Blasphemy! LOL


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## tonyvdb (Sep 5, 2007)

ISLAND1000 said:


> But Tony, what happened? You now show a Onkyo TX SR805 and a YAMAHA RX-V995 in your systems. Blasphemy! LOL


LOL I made a deal with my wife and she said in order to upgrade my receiver to the Onkyo I had to sell one of my other receivers (totally understandable) and I figured that I would get more for the Carver (I did) The Yamaha 995 is not worth more than $100


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## ISLAND1000 (May 2, 2007)

I see . . . grass hoppa


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