Considering two DTS-10's - Other options? - Page 2

I'm not sure that is what WarpDrv was saying and it wasn't what I was saying. I apologize if that is how it sounded.

A sealed subwoofer's bandwidth is dictated by the driver and displacement capability. Different drivers are capable of extending to different frequencies cleanly. This is a function of the driver's design. The LMS 5400 and RSS390HF can easily play cleanly as high as you would ever want a sub to play, at least 150hz.

The low end pretty much goes forever, assuming you have enough displacement for the SPL. That is why the LMS 5400 is an 18" driver with 38mm of excursion. Alternatively, you can use 8 15" drivers with about 14mm of excursion each. They happen to have a nearly identical total displacement (excursion x surface area).

The "cost" for this wide bandwidth is a lack of efficiency. I'm not anti-horn. It is just a matter of application. If you were budget limited and had lots of space, something like the F20 works great. Of course you give up the lowend bandwidth. The output from 20-80hz is quite good and clean.

As far as sealed subs sounding subjectively "stuffy" you will find that sub alignments will sound the same eq'd to the same response...assuming that is even possible. Eq'd the same, the DTS-10 and LMS 5400 would sound the same so long as you only use them within their intended range, both frequency and SPL. The idea of a "sonic signature" is myth.

Regarding low distortion: I had 4) high excursion sealed 18s that sounded clean, in other words didn't announce themselves. It's a dual edged sword though. On music, never a problem, on movies however that low distortion can sound unassuming until you look at the cones and see them going berzerk with excursion and then a bottoming out if not careful. I believe that is the reason guys with sealed have so much cone area and power on tap. When the bass is very low distortion you can get heavy on the volume as it's not as obvious when it's flexing.

For music I like subtle and to blend in. For movies I don't want things to really stick out of place that weren't meant to be, but when it's time to go off I want it to really hit me upside the head and own the room. I have 2) DTS 10s behind which do just that, then I have four sealed subs up front with the mains and the 2 compliment each other nice. I'm at the point now where I'm not interested in swapping anything out, just adding to even the response at all seats and get just a tad more scary in the nether regions.

Tom Danley talks about the Tapped Horn.

Tapped Horn
Horns have been used for decades in sound reinforcement to increase the loading on the loudspeaker driver. This is done to increase the power transfer from the driver to the environment in which the sound is radiated. For maximum power transfer to occur an impedance match between the loudspeaker driver and the free air must be established. A horn is the means to this impedance match. For a horn to operate properly it must not be acoustically small compared the frequencies (wavelengths) it is to radiate.
Conventional horn theory and design formulae are based on this assumption. To meet this requirement the horn needs to be at least one-half wavelength long at the low frequency cut-off of the horn and the circumference of the mouth must be at least one
wavelength. When used for low frequency reproduction this can make for a very large unwieldy horn that can becomes impractical to make or move.

A common practice used to reduce horn size is to make it only one-quarter of a wavelength long at the low frequency cut-off. This short cut has some very interesting effects on a horn's performance. Of note is that a quarter wavelength resonance will
have a velocity minimum at the throat compared to the half wavelength resonance which will have a velocity maximum at the throat. The net result of this is that, while there will be output from the horn in its low frequency region, the horn will not yield
efficient power transfer until the frequency is increased sufficiently to correspond to the horn being one-half wavelength long. This begs the question: Can the quarter wavelength horn be driven efficiently? The answer is a resounding yes. To do so one
must examine the conditions presented to the driver at the horn's throat and match these conditions for maximum power transfer. The velocity minimum condition requires that the proper loudspeaker driver have a much stronger motor (larger magnet) and a
larger moving mass than conventional horn theory dictates. The downside is that this driver is not at all well suited to drive a conventional horn. Once the frequency increases to the point that the horn is at least one-half wavelength a conventional horn is
exactly what we have.
So what we need is a loudspeaker driver that can change its mechanical (Thiele-Small) parameters depending on frequency. No problem because we found the magic stash of Unobtanium! This seemingly impossible feat is accomplished by allowing the radiation from the rear side of the driver to enter the horn at a location (tap) sufficiently far away from the throat (where the front side is driving the horn) and closer to the mouth..

Example of a Tapped Horn
Since the rear of the driver is much closer to the mouth of the horn, at very low frequencies it is effectively de-coupled from the system and its radiation does not affect the total output. This occurs due to the throat end being almost one-quarter wavelength
away. The radiated pressure from the rear of the driver is reflected from the throat end back toward the mouth. The total path length traveled is one-half wavelength (one-quarter down & one-quarter back). The reflected wave arrives 180° out of phase
with the original radiated pressure from the rear of the driver and is thus cancelled.
As frequency increases the situation changes a bit and the rear of the driver begins to be coupled to the horn as the reflection from the throat end does not cancel its own radiation. When the frequency is such that the horn is one-half wavelength long the rear of the driver is fully coupled to the horn. The pressure from the front and rear of the driver are of reverse polarity; a 180° phase shift at all frequencies. The pressure from the front of the driver (at the throat) and the pressure from the rear of the driver (close
to the mouth) are now approximately one-half wavelength apart. This represents a phase shift of 180°. At this frequency both the front and rear of the driver are driving the horn in phase. When this happens the driver's radiating surface area (Sd), as far is
the horn is concerned, had significantly increased (almost doubled). Since the driver radiates from the front and back of the diaphragm, this yields very different driver parameters than when at the one-quarter wavelength resonance condition.

Where in the south are you? You can come by to hear mine if you're close. BTW I have heard both the lms and dts in my room. No comparison. You need a huge amp for the lms. The dts wins in several ways.

Hope I did misunderstand him. Either way, I didn't take it personal. I want JPA to get the best information he can to make an informed decision, and this is some great conversation for that.

Brandon, can you elaborate on the pros and cons of each? I know you have on other threads, but a quick synopsis here might be helpful. You're one of very few that have had both in the same room.

I'm on your way to the manufacturer. I wonder if you placed your order with the caveat that you have an acceptable demo at my place. You come to pick up your subs, save yourself several hundred in shipping costs, and swing by to hear mine. You don't like, you cancel order and go home. Danley are good people. I'm sure they'd agree to that. Eliminates risk on your part.

This likely isn't the thread to discuss your mains, but if you end up with any sub option of this league of subs, and you have a large room, you will definetely be looking for capable mains to do the job. Since you commented on coming from a htib, it's something to start kicking around.

You know your opinion of "no comparison" is highly subjective.

Really all everyone needs to do is use Ricci bench test measurements.

1. The DTS-10 is not an accurate design outside of 14 - 40Hz, it has very high distortion levels outside of its design range because of its design. Inside the range its a thing of beauty

2. The DTS-10 requires a lot less power to incredible output.

3. The DTS-10 is a MONSTER BOX!! If someone can not merge it into the room properly the room will look like some college students room or a bachelar pad with "equipment" sticking out like a sore thumb. Its just a choice but people need to make the decision if they want a beautiful < 4cuft sealed box or a monster PA box in their room. People have to match the decor and lifestyle so again all choice. 4 cuft is just 1000 times easier to handle.


4. Outside of a custom HT room where I can hide boxes, If Im picking a single box, Im going to pick the LMS5400 design over the DTS-10 easily because its superior in so many ways.

5. Obviously if budget is a concern then even one LMS5400 design is not the best $$$/performance option.

The measurements tell us a lot about a design (pretty much all we ever need to make a scientific/valid conclusion) and anyone thinking uncontrolled real world listening tells us something might as well also believe cables make a difference and people should spend high $$ on amps because they make more difference then speakers and rooms. The real point here is that if someone tells a BOSE owner that they do not know what they are talking about how can they go out and post highly subjective opinion about any product when the measurements do not agree with them??

You either want accuracy or you do not. Even Danley recommends "OTHER" choices outside of the 2-octave bandwidth (this is inherent to horn designs). The proof is in the science/measurements and they tell us what is good and bad about the DTS10, Giddy owners that Love peaky midbass response not withstanding. If the only argument is that someone posts "I love it" then we might as throw out science and go accept even audiophile snake oil products too

The conclusion is really if the LMS5400 max SPL is not being hit then it in a sealed 4cuft is superior to the DTS-10 is so many scientific ways that its hard to debate them on a DIY forum where science is always first. If you need more output find a better solution for your $$$

I agree with all of your statement but the real question becomes what is audible to that said person. If one can't hear the differences that measurements provide is it worth it to spend the extra money?

That is the personal buying decision process though. Im not sure how that can be part of any online discussion since everyone has their own way of making a decision. We simply need to post all pros and cons of a product and let the person buying decide.

If none of its audible and measurements are not a pet peeve then buy all means by and enjoy it. Without specific reference points and proper listening controlls is hard to know any difference that exists. Sometimes we are better off not knowing anything

I ask you this, how does reading posts saying something like "I wet my pants the first time I heard it" give a fair assesment against similar designs??? Lets face it anyone that hears either design (level match) is going to wet their pants

I say give anyone purchasing the proper data for them to make their own decision. The data says a box 1/5th the size does an amazing job with output and less distortion.

Hearing them both before I can easily say they are two of the best subs I have heard and I have heard/built a lot. So you won't go wrong with either choice.

For me the the lms is all around the best driver I have experienced, and it has the specs to back it up. Massive excursion, enough motor to fit in small enclosures, highly accurate, and good looking to boot. It has that clean sound that seems hard to impossible to achieve. Extremely low distortion makes this thing sound good.

The plus points I have for the lms is its clean sound, decent output in comparison to subs in general, love the look of the driver, it can be fit in a relatively small enclosure.

The downsides to this subwoofer aren't many but are worth mentioning. The first and probably biggest for me is the amp issue. Yes you could run one of these from an ep2500/ep4000 but really who would? Its like buying a sports car and putting 87 octane gasoline in it. You need a bigger and higher quality amp for this driver. Price is another. While all in all (depending on finishes and amps for each) they will be close to the same price, the driver is expensive. I'm cheap in the first place so spending that much on a driver just erks me a bit. If you have the money that part shouldn't be a consideration. Last point is one that isn't something that should weigh heavily on your decision but should at least be in your head. The company that makes this driver has been a little more than unstable in the past few years. Out of business for a while then back in. So company stability is a point.



While I won't argue the science involved, I will add a caveat to your post (good post too btw). The measurements ricci made were "out of the box" measurements. Not finely tuned like the danley should be. Not saying eq'd to the room, but eq'd for a more flat response at the mouth. Commercial subwoofers add eq and other filters. The same argument can be made for the lms so that's a toss up. But in actual real world usage I can't imagine someone buying a dts-10 and not also spending the $50 or so for a used bfd on craigslist whereas I can easily see someone building a box for the lms and not adding eq. I believe room interaction with sub frequencies merit an eq for any subwoofer, its just that most won't buy them.

I'll bring up a point we have discussed in the past regarding speakers. I've recently changed my surround speakers from a pair of athena bookshelf speakers to a set of klipsch pro audio surround that were used in an imax theater. One of my points that you agreed on was that like my situation, dynamics or sometimes other apects of a speaker are sometimes preferred over the most accurate. People for years have gone against science when it comes to speakers. There has been ongoing arguments for years on whether a speaker sounds good if it measures ruler flat. Most people don't like the sound of a speaker that's completely flat. Why is it that with speakers "sounds good" is in higher regard then accurate? And why is it that the bottom 80-100 hz is different? Below the lowpass crossover everything has to be accurate or it must not sound good. This is hardly an argument I want to try to validate so to sum up this portion all I can say is listen to it. Yes the lms sounds better, but the difference isn't as great as you would imagine.

The pros of the dts-10, to me at least, outweigh the lms. Output is obvious. The dts-10 is a monster. Sensitivity is another. You don't have to have a lot of power to drive it, but it will accept a good amount also. Dynamics are huge. You can push this sub and it just keeps going. And it does sound good. Its not like the dts-10 sounds like crap. It doesn't. It sounds really good. On top of this it is pretty easy to assemble. Last pro, and this is one for me and possibly some others, its huge! That look of amazement people give when they first see it in my room is almost as good as when they hear it the first time. Some people don't like huge subs, but for me I like them.

The cons are pretty obvious. Number one is its size. As said before they are huge. They take up a good bit of floor space. Its also heavy so its not easy to move around. It takes a bit of tweaking to get sounding its best. It also needs good placement to reach its full potential. Its not the most accurat but can be eq'd to sound good. Integration with other non horn subs is also a bit tricky.

Its hard to determine which is the best fit for someone, but ultimately with a room the size of the OP's you need output. The dts-10 has it. If I didn't own a subwoofer but experienced both I would still choose the dts-10. It would take more lms subs to play the same levels a single dts-10 which ends up being more money and potentially more cash spent on upgrading you home electrical system.

Let me also add that th 50 hz and up point isn't as valid as it seems. I am limited to 100 hz due to my ancient receiver. It plays fine to 100 hz. When I have had other receivers I prefered 60-80 hz depending on sub placement and other speakers I had at the time, but at the same time this is with any sub I have had in the room, not just the dts-10.

Penn is right.

In a nutshell, for the same money, the twin LMS setup, in about 1/4 the space is superior in every way I can imagine except for one...you have to build two small simple boxes. We've covered enough to call this one.

Oh and I think I misspoke earlier. Each dts is 24 cu ft external. The rss390hf setup I proposed would occupy about the space of one dts. It shouldn't be hard to find a local cabinet builder to do these for the $900 in savings over the LMS or DTS setups. It is a middle ground solution that is within budget, takes about half the space of the Dts's and gives the performance of the LMSs. Oh and it could be made in 2, 4, or 8 boxes for easy transport and placement and the boxes can be made to fit your space.

I'll be honest, I see no logical reason for the DTS unless someone just doesn't want to do a little legwork and talk to a few cabinet builders. Im sorry if that ruffles feathers.

Mk is right that any of this will "make u wet yourself" especially compared to a HTIB. But the op asked if he should go with twin DTS's and the answer is simply no.

IMO, everyone gets too caught up in the 'one solution is the best' stuff.
Get what you like and enjoy it.

The DTS is a killer solution and with 1000w you can shake your house, your neighbor's and half the block. The boxes are huge but there is not much than can touch it for that little coin down low.

Depending on your driving style that would only make you about 4 hours from my place. Of course there is another better option. Just drive to danley. Should only be about 2 hours from you.

A 2 hour drive would be well worth it for a demo!

You would need two EP4000's for the LMSs. One per 5 cu ft box. You would also need two EP4000's for the RSS390HF solution. One per 4 drivers.

The amount of power needed for a sealed setup is a function of box size.

The DTS would need a single EP4000.

I detailed this in my second post. Even with the extra amp (they are $300 each) the LMS is the same price and the RSS390HF is cheaper than the DTS's.

This difference in sensitivity is not large and is effectively inaudible in this bass region. Interestingly if you put the 8 RSS390HF in 40 cu ft (approximately equal to the twin DTS's) they are actually within a few dB of each other on 1w/1m efficiency. You would only need a single EP2000 for an amp, but frankly it is not necessary to use a box that big. The four 5 cu ft boxes with 2 drivers per would be best.

The DTS is a relatively inefficient bass horn. An efficient horn with a bandwidth from 14-50hz would be 2-3x as big. The F20 is similar in size to the DTS-10 I think but only covers 20-80 and is more efficient.

This may seem like buying a fancy sports car but it isn't nearly as complex or subjective. This isn't a Z06 vs a 911 Turbo where both perform similarly but feel different and look different. With subs it is all about the frequency response and numbers. Frankly, it is only subjective to those with a horse in the race. I have no horse in this race. I've gone down both paths. I even suggest something like the F20 to the budget minded, but for your budget there is only one logical choice (or group of choices).

The F-20's are smaller as I can fit 4 behind my screen and only 2 dts10's within the same space but 3 come close. I have owned many systems and once you have enough spl for movies it is very hard to tell them apart. My sealed 18's had 12 DBS more output at 10hz within 10% THD and it is not noticed during any 5 star bass movie at reference levels. I say buy what looks and fits the best in your room as long as it can hit the spl needed for your tastes, cleanly.

I'll offer that a demo at Danley won't give you any indication of the experience you'd get in my room. I demo'd at Danley. The showroom is a warehouse with no room interaction.

cocto, can you brief us on your experience with the DTS? I wonder what the environment and conditions were. I've heard them now in four different rooms and it was a vastly different experience in all four. There I go again..."vastly".

In 5 cu ft, the EP4000 won't drive it to full xmax, but pretty close. Close enough to equal the DTS in output and you won't need to worry about bottoming the sub. You could find more powerful amps for sure, but the EP4k is enough and a great value. Each doubling of amp power only adds 3db.

The audibility of THD is debated and is really not something that is going to be an issue with any of the proposed setups. This is especially true with actual content. Distortion is mainly an issue up around 70-120hz which causes localization issues.

I've only heard them once in a friends room. I've heard a number of other horns of different tunes and styles (tapped and FLH). Setup properly, you won't tell a difference between any sub alignemtn within their comfort zone

You've hit the nail on the head that the room dominates in the bass frequencies (< ~120hz), but only over the frequency range which the subwoofer can play well to begin with. The ohter thing you are hearing is the interaction between the mains and the subwoofer which is an issue with a subwoofer that is beyond its comfort zone above 50hz.

What is your experience with dual LMS 5400's? Or 8 high quality sealed 15" woofers. What's funny is that you could actually do 12 RSS390HF for the same money as the dual DTS's and it would be no contest.

If it weren't for your insistence on blindly supporting the DTS-10, I wouldn't be so blunt as to say it is a mistake. This is my last post on the topic. Everything that needs to be said has been said.

I'll just assume you did a double blind with dual LMS 5400's and dual DTS's, right?

I have not heard the LMS. I'm not debating the comparison. I'm debating the weight to put on comments such as "distortion" and "within its comfort zone". In my system, I have a fairly flat FR beyond this zone. I'm not claiming the sub is strong or weak in that range, but I am claiming it doesn't equate to a concern (for me) when listening to content on my system. The LMS may very well be the better choice.

I'm not blindly supporting the DTS. I'm claiming that my experience doesn't match the claims here. My experience is not supported by anything other than listening and comparisons with other subs I have access to (SVS, Submersive, F20, Tuba, HSU, JL, Fi IB, etc.). My last post on the topic as well. I think both our points have been made.

Between the two poles of a pair of big/efficient DTS-10's and small/inefficient LMS's is 2 of the new Pi-18's per box, for about the $ame.

How would the lms equal a dts-10 in output with the same power?

"How would the lms equal a dts-10 in output with the same power?"

100 watts at 10m from ricci's site is theoretically the same as 1w1m, so these would be your measurements.

danley specs the dts at over 100db, but that is a 2.83 volt measurement, not a 1w measurement and i think that they also use pink noise with a large crest factor to get another 3 db or so of sensitivity. this is just them trying to keep up with the marketing depts of their competitors. i'm not saying that danley is different in this way. this is why ricci's measurements are so valuable. he isn't gaming the measurements...rather, just trying to be as accurate as possible.

i'm not sure if ricci ever figured out what caused the rippling in the lms sealed measurement, but that is a measurement artifact, not a driver/enclosure matter.

in the lower end of the bass, the danley is about 10db more sensitive, so requires about 1/10th the power for the same spl.

its frequency response is obviously going to be a little more difficult to work with though, but most rooms have modes that create peaks and dips which need some eq anyways.

by the way, iirc, ivan (from danley) mentioned that if he had to choose a danley sub for his favorite, he'd pick th50. not too concerned about sub bass and liked its high sensitivity and power handling for 20hz up. that was a while ago, so he may have a new current opinion.

relatively high sensitivity is an advantage of mr. c.'s suggestion for lots of 390hfs. 4 of them are about $700 and have about 6 db more sensitivity than the lms, so you would only need 1/4th the amp for the same output. that would make for a very interesting shootout. would the linear motor of lms beat out the lower excursion and lower power 390hfs? the 390's would require much larger enclosure volume though.

I had the $$$ to get 5 DTS-10s, 2 for my home and 3 for my van. I DIDN'T get them because they have too much punch! I wanted an exaggerated low end rather than it getting louder as it got higher.







Amen!