Top contenders in their class 15,18,21 inch drivers - Page 6

I can appreciate keeping the thread on track, but hell, don't stop, there have been some tremendous posts.

I, for one, am learning a great deal. Fascinating.

Everyone,
Thank you.

hehe, don't they all

I think everyone still agrees that the numbers behind the LMS 5400 makes it a very unique choice. Im amazed that my box I have built is pretty small and still my sims show great output at 20Hz.

That really is the point, IMO. No one is going to buy a driver and lay it on a shelf and look at it.

That's why I've always referred to subwoofers as a system. Like Josh said earlier, if you can squeeze another dB or 2 from the same system, it makes sense to do it.

Bosso

Have to agree here. There exist eminently elegant engineering solutions on paper, and then there are realpolitik solutions. Sometimes, like when there are head interior designers to please, cubic dollars have to trump cubic inches. Or so I've heard...

Actually damping very slightly decreases Fs.

Which stands to reason in that it’s slowing motion, so the cone comes to rest at the end of each half cycle a bit sooner.

[quote=penngray;19211349]Is it really < 128Watts when dealing with a sealed design that needs +12dB boost down low??QUOTE]

Right; I don’t know why I was thinking about mains when we’re talking subs.

Hey Noah

There is more afoot than the dampening I mentioned. The true source of the dampening from a greater flux saturation is the back EMF generated when the coil is moved. Remember a coil of wire in a magnetic field when moved generates a voltage. The greater the strength of the magnetic field the greater the voltage generated per movement.

That is the source of the dampening.

My source for the conclusion was the last driver I worked on. It was a Lowther PM3 clone. We were using the lightest cone and spider assembly we could find. We even had the cone sanded down to reduce weight. The only route we had left was the strap on a stronger motor. So I machined a one piece pole piece and back plate out of continious cast silicone iron. The top plate was from the same material. THe moving parts were identical. We used the largest slug of Neodymium we could get out of China back then and magnetized it. We pushed the 1 watt/meter SPL up to 108 db. Unfortunately we drove up the Fs 50% above what we started out with. Started out near 50hz and ended up near 80hz. So goes to show yeah not all is intuitive.

Mark

Now get back to talking about woofers!

Wow


That would be from the lower mass.

I think I typed that.

Same parts both situations. Just swapped out the motor. Remember it was a proptotype. We tend to push prototypes as far along as we can. I have to make less parts that way. The soft assembly was used over and over.



But the ones Design by Mark Fenlon at Mark Audio are pretty good. Closest thing to a true full range I have ever worked with. I have been modeling some full range towers ala Don Keele's CBT arrays with a product called the EL70. You big woofer dudes will laugh. 4" but actually goes down to 40 hz in the right box. It also will go up to 24 khz.

Nasty thing to try a push a 6 1/2" driver past 13khz. Most full range drivers are just relying on very nasty resonances up after that point. That includes most of the Fostex stuff. It's all in the phase plug after that. We got to the 5th generation and the client pulled the plug on the driver. Sucked cuz we were so close!

Mark

"the moving parts were identical"

Fs went up from motor changes alone, not sanding the cone?

The fact remains that the only way to change Fs is by changing mass or stiffness, as can be found in any text on the subject.

I cured my problems with no connection/slow connection/timeouts with the AVS Forum with Firefox and the NoScript plug-in. Things are lightning fast now and I can finally return to reading this forum.

what about that new Re MX or whatever with neodymium 4" VC motor ?

Been using that one forever. Adblock is very nice as well.

I just pay the AVS membership yearly to not have any issues with ads.

I agree with that, but you contribute on this forum and they should be paying you for being such a great worker for them helping all that come here with great advice.

Firefox with adblock plus addon - takes all the ads out for you, free....

Hmmm. I have no issues at all with AVS ads or pop ups and I just use IE on my win7 machine. Although I'd really like to incread my PM box space so I think I'll be joining up too. Plus, I want a wicked cool avatar too.

Per a thread in the receiver forum, I just switched from IE to the google chrome browser and it seems ~4X faster, most notable here at AVS.

lmao, where is the wink on that one? I could not even say that with a straight face


Cool to know about the firefox, chrome improves speed and removes ads. I paid mostly to increase my PM box. Its still always full, I would like 5000 and not 500 messages stored in history.

No wink necessary IMO - your a great example for everyone on this board - your a do-er not just a talker. You talk the talk, but you also walk the walk and show example of how your learning just about every aspect of audio through experimentation with your building things many would never even think to attempt, which sparks many a great in depth discussion. I commend you for that sir...

Here - just a simple example - I just did a search of threads started by you just in the DIY area alone - and came up with 126.... some that went no where and some that have hundreds of posts. This is how other people learn by just reading here - which also dispels many a myth in audio. Keep up the good work my friend. So please don't take it like I'm blowing smoke up your @$$.

And to all the others that bring their knowledge base to the forum - I/we thank you for your time and education.

I'm bringing this thread back from the grave as it has some information that I am finding very useful in my first DIY sub project. I'm impressed with the technical knowledge being offered, but, I must admit that most of it went straight over my head. I was hoping someone could help me read between the lines to determine what drivers to go with.

Here is my criteria:

1. Want a sealed design.
2. Two separate cabinets..
3. 15" drivers
4. Each enclosure with two drivers in a dual-opposed design.
5. No limit on size of cabinets
6. I have no amplifier yet so that can be purchased to best meet the needs of the driver/cabinet design.
7. I have no room or interest in an IB design.
8. I want quality drivers, but, not necessarily a "cost no object" choice. If there is a driver that is 95% performance of the best, but at a price 20% less than the best, that is what I prefer to purchase. I have no desire to chase after that last 5% of performance. Once I choose the drivers I am hopeful the cabinet design and amp selection will just be a matter of proper modeling.

I have considered the Fi Q series, Dayton Titanic, TC sounds LMS, and others. It seems they are all good drivers, but, each performs best in certain cabinet designs or with a certain level of power. I am hoping that considering the criteria above I can get some suggestions for a quality driver. If price were no option, which it is, I would go with the LMS ultra 18". However, since I am not limited on cabinet size, perhaps a lesser priced 15", in a dual opposed design, will equal the performance of an ultra.

My room is an open family room, 5,000 to 6,000 ft3. My speakers are Aerial Acoustics LR5's (three LCR)crossed over to the subs at 80 hz. I am 90% home theater, but, want quality bass to complement my Aerials when I do listen to music. Before drinking the DIY kool-aid I was about to pull the trigger on one (or two) Seaton Submersive HP's.

Thanks for any input

http://www.istonline.ca/mach5_uxl_18.html or the 21 inch ones .

Thanks- I have read positive reviews of the Mach 5 drivers. Are you suggesting I go with only one of the uxl -18 drivers in each cabinet?

If you want to stay in the 15" dual opposed route than 2 dual opposed LMS-R 15's would be the best SQ match to your Aerial LR5's which are excellent speakers. A pair of LMS-R 15's outperform a single LMS Ultra so 2 enclosures with dual opposed LMS-R 15's in them will beat a pair of LMS Ultra 18's.

uxl is about 95% of a lms ultra for 60% of price.

Hmmmmm. Have you heard both subs in the same system before? I know my Mal-X 18's are excellent subs but the LMS Ultra's I used to have were better as they were more accurate and just felt more visceral. The best way to describe the LMS Ultra is accurate violence, at least that's what it was to me. I also had the LMS Ultra at the same time as the Mal-X 18" and they were tested in the same 4cuft enclosure, amp, EQ and location.

I loved my ultras when I had them...That being said, I'd never buy one again.

Don't get me wrong, I am not trying to put down Mark's products, I am really tempted to buy some of his offerings and the items I have bought in the past from him were always great. I was just wondering if Cookieattk was talking from experience or just going off of sims from WinISD or something. Sims only tell part of the story, real world experience can differ greatly.

I almost pulled the trigger on 4 of the FTW-21's from Mark but to order them now going into my busy season would mean they would just sit unused until after X-mas. If I lived in Canada and could pick them up then I would not hesitate to pull the trigger even if I had to wait for build time, I might even challenge you N8

I wonder if you would buy the LMS Ultra's if they were made in Canada and close enough for you to pick up in person?

Thanks for the input.

There seems to be a lot of interest in the 18" drivers; whether it be the LMS Ultra or the Mach 5.

If I decide to go with 18" drivers I will need to go with only a single in each cabinet as using duals would stretch beyond my budget. I know, at least with the LMS Ultra, that the 18" is a higher quality design than the 15" LMS-R. Would the single 18" be a better option than dual 15's (in a dual opposed design)?

Edit- Nevermind. I see that MJ has already answered my question in post #172 above.

I have never tried the LMS-R 15", only the LMS Ultra 18" but in talking with Thilo Stompler, the owner of TC Sounds, he tried to convince me to go with dual LMS-R 15" rather than the LMS Ultra as he said the price was lower but the performance was higher. A lot of what he told me made sense, instead of one large motor you are distributing the power of 2 smaller motors and they both employ the low distortion LMS coil. You can call Thilo over at TC Sounds and discuss it with him personally, that's what I did. I went with the LMS Ultra though as I always regretted not buying them when TC Sounds went bankrupt the first time.

If the LMS's were the same price as the UXL's? I'd have a much harder time picking one. But as it stands, for me anyways, the LMS's are not a good option for their price. They are over 1K each after boarder and taxes and shipping. I can get 2 UXL';s for that and spend less on the amp and get more performance for my money. I'd much rather support Mark than TC sounds. Thats just me though. It's not to often you have a chance to buy awesome subs locally!

If I was in your position I would do the same, the smart thing to do. Tell Mark it's great out here in S. California all year round if he ever wants to relocate