sealed subwoofers better than all ported subs with music?

[TLS Guy]

Actually, I think a sub is about the only speaker you can spec, and know how it will sound before building it.

Whether a sub is ported, or sealed is determined by the driver parameters. Ported subs will tend to a lower F3. The problem is that there is a lot of air movement from the port, so port design is a problem. Often you are between high port velocity and port resonance.

If you can make room for it, and or disguise them as something else, a TL sub design has a lot to recommend it. I don't believe there is a TL sub on the market. To me the deep bass from a TL sounds superior to anything else. I would never give it up without a fight. And not just to me either. I have had quite a few hear my rig now and they search and search in vain to try and duplicate it.

 

[Sheep]

I agree that bias can make a big difference. If the answer is blind testing or not, I don't know.....
But It helps to have an open mind )

John Dunlavy, perhaps the greatest speaker designer of all times only created sealed boxes because he thought they performed better, I'm not saying that he's definitely right, but it would be hard to argue with a legend like Mr. Dunlavy......

-H

I hear Bose is quite legendary.

SheepStar

 

[Seth=L]

You remember 30 years ago when all amplifiers were perfect and everybody believed that if an amplifier measured perfectly, you couldn't get anything better!

Most amplifiers are transparent. When any amplifier that is designed to be transparent and performs as such is operated within its design parameters it will sound the same as a like amplifier in the same setup.

We know better now !

Who's we, the audiophile community that still believes cables make an audible difference?

You remember when the CD was introduced and it would provide perfect sound for everyone because it measured perfectly. Anyone using his/her ears would notice that this was certainly not the case.
We know better now !

I have used a Magnavox CDB650 and a Pioneer Elite PD-65 side by side and noticed zero difference with the same program material. The difference is only measurable by equipment, not by my ears. My ears have been tested and are in good working order.

b.t.w. What do you mean by measuring perfectly?

I don't much of the technical measurement protocols, I haven't gotten that serious about subwoofers living in an apartment.

Do you know that a human ear's hearing threshold is at the level that if the eardrum moves less than the diameter of a hydrogen atom, a human ear may hear this, I'm not sure that a measuring device is that good

Measuring devices can pick up a lot more than our perceptive hearing can. Our ears are very sensitive, but there is much more sensitive testing equipment from my understanding.

I couldn't disagree more with you. Do you really buy equipment from measurements?

My question was not rhetorical, so there is nothing to disagree with on that post. It was just as it reads, a question, that was all. The question was not directed at you.

Measurements are important!!!!! But everything would need to have a balance, what if a device measures perfectly but sounds like crap!

-H

Maybe acoustic accuracy pains you because your program material isn't good.

 

[Sheep]

Seth! Throwin' it down!

SheepStar

 

[Seth=L]

Seth! Throwin' it down!

SheepStar

It's funny, I wasn't even expecting such a response. It's all good and fun anyway.

 

[no. 5]

You remember 30 years ago when all amplifiers were perfect and everybody believed that if an amplifier measured perfectly, you couldn't get anything better!

We know better now !

Indeed, but just because something measures "perfectly" (according to a reviewer, or manufacture, or whoever) does not mean that the measurement was of the right thing, or made the right way, or even a useful measurement: to illustrate, it has been known for some time that low THD is good, and when solid state amplifiers started becoming more common, it was found they could be made to produce much lower THD than tube amplifiers, which conventional wisdom said should be better, but often they sounded worse than their tube brethren.

Why?

Because the measurement, though usefully, was not being made in a usefully way; the THD measurements were made at full power, because it was assumed that solid state amps would behave the same as tube amps, but they don't exactly: at very low power output solid state amps can produce audible THD levels, a behavior tubes don't share. Once that was found, solid state amplifiers could be made that performed better.

Do you know that a human ear's hearing threshold is at the level that if the eardrum moves less than the diameter of a hydrogen atom, a human ear may hear this, I'm not sure that a measuring device is that good

Yes, the ear is very sensitive as you well illustrated, but not it does not have the same acuity for all things, and it is not an absolute when it comes to measurements; the quietest place on earth (according to the people at Guinness) measures -9.4dBA, the quietest thing a human can hear is 0dB at around 3kHz (higher and lower frequencies must be of higher SPL to be audible) so the quietest place on earth is 9.4dBA lower than the threshold of audibility, consider phase too; small differences in phase are measurable, but our hearing is largely tolerant of phase issues introduced by a loudspeaker system.

Now please don't think I am of the opinion that "if measurements X Y and Z are "good" than it doesn't matter what it sounds like", but rather that good measurements are a tool in achieving good sound.

 

[TLS Guy]

I've only performed a cursory read on your posts guys...but I think we all know the answer to that question: Can he reduplicate that sub for $600 wholesale? I'm pretty sure it's rhetorical, but since no one has given an answer...I will. It's a resounding NO!

A key part, I believe, left out of the equation, is TIME. Time procuring the parts (researching, searching, purchasing, taking delivery), and time to fabricate, assemble, wire and finish the sub. I don't know how that can be done for $600 in labor alone! And though I'm not a sub builder, I have employeed people in the trades for years. Without saying as much, I believe that is his out of pocket cost...no money for his time, labor and efforts.

So, it's a beautiful sub, and it may very well be a powerful and efficient and accurate sub, but one needs to consider more than the cost of materials when in business. This in no way takes anything away from avaserfi, or his efforts. He certainly seems to know what he's doing. And this may be a good project for anyone else with the skills, tools and know-how that avaserfi possesses. Could it be sold at $600 for a profit? I don't see how. But congrats on a job well done avaserfi.

I think there is a wider issue here though. I think Averserfi is going about it correctly. I think any reasonably intelligent person could research and understand the physics behind sub design. With that knowledge and construction skill, it should not be too difficult to best the commercial designs. All for the reasons you site about production costs.

I'll say this again and again, every serious audio enthusiast should ask themselves repeatedly: "Why am I not building my own speakers?"

 

[InTheIndustry]

Seth, to make sure I understand you correctly: Two amplifiers that are designed to perform exactly the same do, in fact, perform exactly the same? That, I most certainly agree with!

Here's a quote from a review to read for the "Receiver Amps are just as good" and the "All amplifiers sound the same" crowd. And, yes, I'll tie it all together with the ported sub/sealed sub stuff.

"We decided it was time to run some comparisons to see what profound differences we would hear when running the PM-11S1 against some admittedly odd competition. It was a clear demonstration of how amplifiers do indeed sound very different from one another - especially when comparing a high-end system with a mid-fi system, and more so when comparing to an entry level product that exhibits more distortion than a Metallica concert. In comparing between the Yamaha RX-V2700 and the PM-11S1 the general description would be that the RX-V2700 sounded warmer, with looser bass and slightly less clear highs. The Yamaha still sounded good, but the Marantz was mind-blowing. For fun, we also connected the cult-status "audiophile" $200 Panasonic SA-XR50 receiver for an A-B-C level-matched comparison. The difference was now amazing. Nearly gone was the gentle reverb that followed the plastic wood block in Dianne Reeves' "How Long" track. As near as we could figure, this was due to the high output impedance (almost an ohm) as well as the increased noise floor of the poorly designed Panasonic digital amplifier. To be fair, having this low profile receiver driving a pair of T30-LSEs wasn't exactly a fair match in anyone's book, but surprisingly some “audiophiles” do this very thing and proclaim sonic nirvana. It was a fun, non-technical comparison but an educational one nonetheless."
Clint DeBoer

Here's the link to the full review, which is a really good read:
http://www.audioholics.com/reviews/amplifiers/marantz-pm-11s1-integrated-amplifier

While I don't normally quote reviews in making an argument (in fact, I actually denounced that earlier in this same thread), I felt that it was an acceptable example because it's from this very same site that we all know, love, and trust to be non BS. The Yamaha RX-V2700 receiver ($1700) they tested against the Marantz integrated (Reviewer states $4400 but MSRP is now down to $3600) has a claimed 140wpc into 8ohm against the Marantz piece's claimed 100wpc into 8ohm. As Clint stated, the Marantz product way out performed it's claimed power output. Guess what, folks... Yamaha, according to the Yamaha rep, OVER states their real world power ratings by a fair margin. The Onkyo rep confessed to the same thing, even going as far as to complain that out of all the major brands the disparity on Onkyo's "Spec Sheet" and what their product's real world output is could possibly be the largest gap out of all the major manufacturers. He said that the complete opposite used to be true, which I agreed with, and that the company seems to really be caught up in the video processing game. Marantz & Denon receivers are off a little bit as well. This isn’t new news to some as it’s been happening for years. The reference line in Clint's review is designed and cut from a different cloth than their receivers, which I still feel offer the best sound in that category. And don't even get me started on the video market. That side of the business has gotten way out of hand because nothing's really standardized. It's a free for all as to what methods a manufacturer uses to build their spec sheet. It's absurd!

Note: Clint’s review has prompted me to spec this integrated amp into the two channel area in our new showroom (opening early May). I figured I’d give it a try and will be ordering it soon. At the very least it looks extremely serious!

My point is, and has been: Some manufacturers, regardless of product category, fudge their specs or create environments &/or parameters to test in that achieve a numbers goal. I know, I know. Third party testing... blah blah blah. Only a small percentage of gear is ever third party tested and a lot of those tests are performed by the same shady reviewers that you all malign and bash (some of them rightfully so). You'll potentially miss out on a lot of really great products if all you look for are testing results. You might also find some really great products by investigating test results, too!

Like I said in my defense of my support for sealed over ported: It depends on application and taste. Products like the HSU VTF-3 MK3 w/ Turbo are, to me, ridiculous. It might be the ugliest sub I've ever seen. Upon site of HSU's add for it I ask myself the rhetorical: "Who would accept something that ugly in their home". But, the answer is crystal clear: Someone who doesn't really care or will accept function without form. With that HUGE ported, Quasimodo like, hunch on the back it could never go into a built in cabinet and be able to still function properly. Nor could the SVS for that matter because to obtain their output goal they had to make the thing GIGANTIC. Buuuuut, their target audience is obviously OK with that. It's an amazing product, no doubt.

Question: Ported subs are, in general, cheaper to design and manufacture. Do we all agree on that generality? If you do, then my next question is: If ported subs can yield the same or inaudibly close performance results (a basis of many of your arguments) why would a manufacturer go through the trouble of going with the more expensive design of a sealed box? Why would a for-profit business bother to spend the time & resources, not to mention risk pricing themselves higher than ported products with the same performance? Answer: They wouldn’t if the sealed design didn’t yield a difference that their engineers preferred.

As far as what Averserfi did, I think that's great if he had fun, built a product he loves, and saved himself some coin in the process. But it's unreasonable to think that any "reasonably intelligent person" would want to, or have the ability to, take the time to research, design, and build their own speakers. Think on a Macro scale. Masses aren't going to do that. It's not practical nor, for some, would it make financial sense. Look at how many people pay someone to mow their grass!

As far as the JL 13W7 being $500, so what? Do you think that represents pure manufacturing costs of the driver? There's no way. I'm also tired of all the pissing and moaning over "mark up". What do you think you and everyone else’s paycheck is made up of? Uhhhhh.... healthy mark up, maybe? People benefit from mark up and it's okay. Mark up costs them some $ and it's unacceptable. That’s hypocrisy.

Fact: A single, very high quality, 10 Meter HDMI cable that retails for $150 costs $18 - $20 to manufacture, ship, and deliver to the East Coast from mainland China. Dealers buy it from that manufacturer for around $60 - $72 depending on annual volume. Regardless, home audio equipment is luxury goods. All hobbies are, period. Many manufacturers & dealers treat it that way and, with some gear, they should. You want it, you pay for it or build it yourself if you're capable. Also, I would absolutely estimate that the parts to physically build a Fathom F113 cost $600 (possibly less). But, as I pointed out in an earlier thread there are many more costs of business piled onto that, which are then passed on to the dealer, and then to the consumer.

I covered a lot of stuff in this post, if I missed something I am sorry. Let me know what, or rebuttal my thoughts. I'm a firm believer that "I don't know what I don't know", so I really enjoy and truly do respect all of the different perspectives and examples that this thread has brought out. It's healthy to discuss this stuff and ask questions because, I hope that, at the heart of this, we're all looking to expand our knowledge base and discover new ideas.

 

[mike c]

cost of production for either sealed or ported is irrelevant to this thread.
amount of time for production is irrelevant as well.
where the subwoofers are made is irrelevant.
looks of the subwoofer is irrelevant.
where the end user will place the subwoofer is irrelevant.
who will install the subwoofer is irrelevant.

you seem to keep fudging your points: e.g. sealed is better because HSU is ugly. huh?

my argument:
sealed is NOT superior to ported nor is ported superior to sealed.

if you disagree, please provide us with objective proof that this is not so. because I have already provided mine.

i will accept a double blind test result, since this is scientific in approach and not based on sighted biases.

 

[haraldo]

Yes, the ear is very sensitive as you well illustrated, but not it does not have the same acuity for all things, and it is not an absolute when it comes to measurements; the quietest place on earth (according to the people at Guinness) measures -9.4dBA, the quietest thing a human can hear is 0dB at around 3kHz (higher and lower frequencies must be of higher SPL to be audible) so the quietest place on earth is 9.4dBA lower than the threshold of audibility, consider phase too; small differences in phase are measurable, but our hearing is largely tolerant of phase issues introduced by a loudspeaker system.
.

I guess some of the main points I wanted to make is that measurements are indeed very important. A product that measures incredibly well may sound good. A product that does not measure well is guaranteed not to sound good. There's balance to everything and that goes with this too. The point with the sensitivity of the ear is that I wouldn't be surprised if we may perceive audible differences between things that we don't even comprehend how to measure.

Heck, we still don't even know what gravity is and how it works.......

-Harald

 

[mike c]

Heck, we still don't even know what gravity is and how it works.......

-Harald

err. who's we?

 

[haraldo]

err. who's we?

OK: Heck, I still don't even know what gravity is and how it works.......

 

[TLS Guy]

Question: Ported subs are, in general, cheaper to design and manufacture. Do we all agree on that generality? If you do, then my next question is: If ported subs can yield the same or inaudibly close performance results (a basis of many of your arguments) why would a manufacturer go through the trouble of going with the more expensive design of a sealed box? Why would a for-profit business bother to spend the time & resources, not to mention risk pricing themselves higher than ported products with the same performance? Answer: They wouldn’t if the sealed design didn’t yield a difference that their engineers preferred.

I do not agree that a sealed sub costs more to manufacture than a ported one. To make a good sealed sub the driver cost may be a little more, but not necessarily. The F3 point is always going to be significantly above the F3, the free air resonance of the driver. So Eq will be required in the amp, stressing the driver, and adding distortion. Complex servo systems may be required, but these have a set of evils in and off themselves. The cabinet will generally be smaller which is a significant cost saving.

A sealed design comes with its own set of advantages and disadvantages. I will say this that a sealed design, that has linear output to 20 Hz is going to require what I term "brute force engineering", which in my personal view is less than elegant and inherently wasteful.

Now to do a ported sub properly, the enclosure is likely to be larger than sealed. This is an expense, alone. However the larger the enclosure the more trouble and cost should be devoted to bracing. F3 points at or a little below the Fs of the driver can be obtained. Large drivers in boxes tuned to the 20 Hz region are going to have large air velocities in the ports. I would submit the construction of optimal ports is very expensive, which is why it is not done commercially. So I think the ported sub will more likely produce greater, deeper and cleaner bass output then the sealed design, but that its cost will be greater.

A TL would be the largest and costliest of all to manufacture, but would have the potential to deliver the deepest and cleanest bass of all, without any vent compression and less distortion issues. That is why they have had a strong following among home constructors over the years. I do think it practical for enthusiasts to build their speakers. Years ago it was very common. I think people have got lazy, mentally and physically. The home constructor now has at his disposal more resources and design aids than ever. There has never been a time in the history of audio, more conducive to the home constructor. A sub is a quite a good place to start, as it is the art of crossover design that is the toughest to master.

 

[Johnd]

I think there is a wider issue here though. I think Averserfi is going about it correctly. I think any reasonably intelligent person could research and understand the physics behind sub design. With that knowledge and construction skill, it should not be too difficult to best the commercial designs. All for the reasons you site about production costs.

I'll say this again and again, every serious audio enthusiast should ask themselves repeatedly: "Why am I not building my own speakers?"

Well I'm happy to see your lackeys have scratched your back. Why they felt the need to scrath that itch I'll never understand. You appear to disagree with my post..but then do not. You state there are "wider issues" present. And you receive many kudos from the backscratchers for that. Why? Did I ever state that my post is the beginning and end of the discussion? The Alpha and the Omega? Did I ever state that the topic I commented on was far more important that any other issue? Critical reading is at an all time low, and I shudder for our future. I fail to see the benefit of resounding applause for something that is already blindingly apparent to most: diy subs can be an economic means of getting great bass at low cost.

Just kidding...just kidding TLS Guy (and the backsctratchers). It's Saturday morning, and I ramble and rant with no ill intent. Consider this Saturday morning satire. Let me have my fun.

I'm glad you have so many to agree with you (why they need to thank you is beyond my grasp...I'm limited that way ), but my post stands true. I care not to speak of others' acumen or abilities. Someone posted that this sub could be made for $600...and my plain comment is that it can NOT when one includes labor. That is what I confined my post to...whether there are "wider issues" present does not concern me. I was confining my post to cost, and specifically commercial build cost versus diy build cost.

You then seemingly disagree with my post. Actually, you wrote that there are "wider issues" present, and state that we all should build our own subs if so inclined. I don't know if that's gonna happen. You have received resounding applause for displaying the blatantly obvious. If you read my post again, you'll find that I never stated no one else should ever to attempt a diy sub...never. My comment is true, and I stand behind it...this sub as one posted could not be commercially built for $600...I believe the builder accounted only for his out of pocket costs...and nothing more. So I speak not to others desire to try to reduplicate this feat... as it may certainly be worthwhile venture for those with the skill, knowledge and tools.

Now. As to your question (everyone has thanked you, but has not done the courtesy of responding to your simple question...so I will indulge myself): Many of us have:
- other interests
- limited time
- ample funding to purchase manufactured subs
- no tools
- no sub building knowledge
- no skills
- no patience

To any confused party out there...this is John's Saturday morning satire. He agrees with much of what has been written in this thread, but hasn't the time or energy to thank each poster, or comment on each and every detail. Satire. A different spin for Saturday morning. A Good Saturday morning to all!

 

[haraldo]

I have done a bit of calculations too see how a given sealed box sub would possibly perform. These calculations are based on the usage of 3 Soundsplinter RL-i 10 drivers (10") in each sub. All these figures are based on the published Thiele/Small parameters. In real life the actual parameters may be significantly different from the published, which means these figures may be quite inaccurate. These drivers are manufactured by TC Sounds, which also provides all the drivers to SVS Subwoofers.

The basis for the figures are as follows:
- Each sub contains 3 RL-i 10, 10" drivers
- Subwoofer is positioned completely into the corner
- Internal cabinet volume = 64 liters
- Room gain is included in the fugures
- Heavy equalization is required to get flat in room response

Please find the attached .pdf wirth the calculations showing filter curves, sound pressure, cone displacement, power requirements
- SoundSplinter RL-i10 - 3 - 64 liter.pdf - At "full throttle"
- SoundSplinter RL-i10 - 3 - 64 liter.pdf - At "2 watt"

I wonder if this tool works, because the figures seem very optimistic.
Maximum in room response exceeds 120 dB, you need 550 watts peak to get there

However, if you stick to SPL's below 105dB (which is still very! loud) the figures are interesting
Max: 2.5 mm cone excursion
Power requirement: 10 watt including eq.

Please remember that these figures caters for room gain!

These results surprise me because if this is correct the sub will be affordable, performance will be awesome, and you can easily meet any music and theater requirements that anybody anywhere would have.

The only thing I'm now wondering about, Is the tool I'm using seriously flawed ==:-O

Cheers

Harald

 

[TLS Guy]

I have done a bit of calculations too see how a given sealed box sub would possibly perform. These calculations are based on the usage of 3 Soundsplinter RL-i 10 drivers (10") in each sub. All these figures are based on the published Thiele/Small parameters. In real life the actual parameters may be significantly different from the published, which means these figures may be quite inaccurate. These drivers are manufactured by TC Sounds, which also provides all the drivers to SVS Subwoofers.

The basis for the figures are as follows:
- Each sub contains 3 RL-i 10, 10" drivers
- Subwoofer is positioned completely into the corner
- Internal cabinet volume = 64 liters
- Room gain is included in the fugures
- Heavy equalization is required to get flat in room response

Please find the attached .pdf wirth the calculations showing filter curves, sound pressure, cone displacement, power requirements
- SoundSplinter RL-i10 - 3 - 64 liter.pdf - At "full throttle"
- SoundSplinter RL-i10 - 3 - 64 liter.pdf - At "2 watt"

I wonder if this tool works, because the figures seem very optimistic.
Maximum in room response exceeds 120 dB, you need 550 watts peak to get there

However, if you stick to SPL's below 105dB (which is still very! loud) the figures are interesting
Max: 2.5 mm cone excursion
Power requirement: 10 watt including eq.

Please remember that these figures caters for room gain!

These results surprise me because if this is correct the sub will be affordable, performance will be awesome, and you can easily meet any music and theater requirements that anybody anywhere would have.

The only thing I'm now wondering about, Is the tool I'm using seriously flawed ==:-O

Cheers

Harald

That does not seem a very promising driver. In that enclosure a boost at 12 db per octave is required starting at round 70 Hz. The sensitivity is already low at less then 85 db I watt one meter. That would not be high on my list as a driver choice for a good sub.

 

[haraldo]

That does not seem a very promising driver. In that enclosure a boost at 12 db per octave is required starting at round 70 Hz. The sensitivity is already low at less then 85 db I watt one meter. That would not be high on my list as a driver choice for a good sub.

It actually needs a total of 9dB equalization, and it's not 12dB/octave.
I dont think this kind of eq. is unusual to such a closed box sub.......

 

[TLS Guy]

It actually needs a total of 9dB equalization, and it's not 12dB/octave.
I dont think this kind of eq. is unusual to such a closed box sub.......

You will need 12 db, you always do to Eq a sealed enclosure. Also the Qtc is around 0.5. That enclosure will sound bass shy what ever you do.

 

[haraldo]

You will need 12 db, you always do to Eq a sealed enclosure. Also the Qtc is around 0.5. That enclosure will sound bass shy what ever you do.

That's just not correct. If you put the sub's in an anechoic chamber that would possibly be the case, but when considering the low Q of 0.5 and the benefit of room gain things are very different.

If you look to the closed box subwoofers from, say, Richard Vandersteen they are all tuned to exactly Q = 0.5, and he's also using active equalization. Some people claim that Vandersteen sub's are the best there is for music, at any price. I'm not saying that's correct, merely stating that such claims have been made........
In my mind, the whole idea of getting a closed box subwoofer working is to put it in the corner and get the benefits of room gain, this works the opposite way as the rolloff of the sealed box. You cannot consider how a subwoofer performs without countering for the room gain. But by putting the sub in the corner you WILL need equalization, no matter what you do......

A sub that's ruler flat to below 20Hz with a -3dB point at 17Hz, using 9dB equalization... that' doesn't sound like bass shy to me.

But this is moving away from the original subject of the thread, so I'll stop this discussion. The idea was to provide some samples for closed box sub.......

Regards

Harald N

 

[TLS Guy]

That's just not correct. If you put the sub's in an anechoic chamber that would possibly be the case, but when considering the low Q of 0.5 and the benefit of room gain things are very different.

If you look to the closed box subwoofers from, say, Richard Vandersteen they are all tuned to exactly Q = 0.5, and he's also using active equalization. Some people claim that Vandersteen sub's are the best there is for music, at any price. I'm not saying that's correct, merely stating that such claims have been made........
In my mind, the whole idea of getting a closed box subwoofer working is to put it in the corner and get the benefits of room gain, this works the opposite way as the rolloff of the sealed box. You cannot consider how a subwoofer performs without countering for the room gain. But by putting the sub in the corner you WILL need equalization, no matter what you do......

A sub that's ruler flat to below 20Hz with a -3dB point at 17Hz, using 9dB equalization... that' doesn't sound like bass shy to me.

But this is moving away from the original subject of the thread, so I'll stop this discussion. The idea was to provide some samples for closed box sub.......

Regards

Harald N

The problem is that room gains are all over the map. To me a Qtc of 0.5 sounds like a bass that stops before it gets going. I know some rock enthusiasts like low Qtc, but for classical music it is on the low side where to me 0.7 to 0.75 sounds much better. I have to say I don't like the last octave reproduced by sealed enclosures. The bass strings and especially the bass organ pipes sound quite unnatural to me. A speaker cone is actually not a very efficient acoustic coupler at low frequencies. A well deigned port, especially a large port from a TL is much better.