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The BMS group buy thread!!! - Page 15

post #421 of 492
Quote:
Originally Posted by coctostan View Post

Can you provide measurements of some sort to back up rise time or the ability to reproduce complex music?

Here is a comparison of a BMS and B&C driver. The signal is a mixture of three different tones, so as to be a complex signal.
The most telling is not the harmonics, but the IM distortion, which will stand out to the ear much more.

post #422 of 492
Jack, I don't want to sound like a jerk, but that comparison is typical manufacturer fluff. And actually a disappointing comparison from any big manufacturer like BMS.

Those charts compare a BMS compression driver with a poly diaphragm to a B&C model with a titanium diaphragm. Of course the titanium is going to have a bit more distortion. wink.gif

The DE250 uses a polyimide diaphragm, not titanium.

BMS makes some great products, we all know that. but there's no real reason for their marketing team to use unusual methods to get their sales point across. Like claiming their 1" poly units can handle 450 watt peak power with a FR of 500hz - 20khz. It's simply not true.
post #423 of 492
Quote:
Originally Posted by Erich H View Post

Jack, I don't want to sound like a jerk, but that comparison is typical manufacturer fluff. And actually a disappointing comparison from any big manufacturer like BMS.

Those charts compare a BMS compression driver with a poly diaphragm to a B&C model with a titanium diaphragm. Of course the titanium is going to have a bit more distortion.

The DE250 uses a polyimide diaphragm, not titanium.

Sorry Erich, that is all I got. If I had a chart comparing your driver I would.
I get the feeling that BMS is being called late to your party for the diaphragm material, but a polyester blend is the only material they have used for diaphragms since the beginning in the mid '90s.

The chart is supposed to show the difference between BMS and a conventional driver, as asked in the quoted post.
To me, just having a poly diaphragm does not make the drivers equal. As you claim.
Quote:
Originally Posted by Erich H View Post

BMS makes some great products, we all know that. but there's no real reason for their marketing team to use unusual methods to get their sales point across. Like claiming their 1" poly units can handle 450 watt peak power with a FR of 500hz - 20khz. It's simply not true.

1) The specs are at recommended crossover point, not 500hz.
2) There are differences in BMS Voice Coils that you are not aware of.
3) You have never even seen one of their products until last week.
4) You have not tested this, and really are just making unfounded remarks now.
post #424 of 492
Quote:
Originally Posted by Aaron Smith View Post

This has to be one of the most interesting group buys ever. The guy that spearheaded the effort and was going to be responsible for about a third of the $20k MSRP total all by himself is out, and the guy receiving the pallet has no idea when, where, or any details about who bought what (and has no vested interest in the items and actually sells compression drivers that compete with some of the BMS). Wow.

Quote:
Originally Posted by Erich H View Post

Having said that, I have learned something else over the past year. Customers can also be interested more in something just because of price, different brand, or newness.....regardless of data.

Now he is bagging on the companyt, and if I am reading him right, is calling everyone who is buying the product in the group buy stupid for spending more money, just because it is a different brand and costs more.
post #425 of 492
overly dramatic are we now ...... first off your testing a titanium dome vs a poly 2nd its not a 4550 and a de250 so it really has no relevance to anything here other then a $250 cd is better then a $170 one.
post #426 of 492
I'm not putting anyone here down at all. But when funky manufacturer comparisons are posted, shouldn't they be pointed out? Shouldn't someone warn that their 1" CD will not handle 450 watts, or have an FR starting at 500hz like the spec sheet says? We do it all the time in the subwoofer threads when helping others with designs.

Sorry, I've clearly said many times that they make great products and they sound great so I'm not sure how that bothers you. I was just saying the comparison they made in that distortion chart is flawed because they're comparing a poly diaphragm to a titanium one. It's strange that they wouldn't compare poly to poly because the DE250 has been around long enough to compare it to.

This could be the first time in history that someone has said "This product sounds great and performs pretty much just like this other great sounding product".......and somehow ruffles feathers. wink.gif

I'll stop posting about how good they sound and just focus on packaging. biggrin.gif
post #427 of 492
Quote:
Originally Posted by Jack Arnott View Post

Here is a comparison of a BMS and B&C driver. The signal is a mixture of three different tones, so as to be a complex signal.
The most telling is not the harmonics, but the IM distortion, which will stand out to the ear much more.


Thanks Jack. I appreciate the effort. I understand it can be difficult to find actual tests. I'd like to hear what BMS used as their explanation for the superior performance.

What these others have said is true though in that the DE500 is not a good sounding CD. We already knew it had higher distortion and the nasty titanium sound. Maybe that explains the higher IMD...or maybe the BMS advantage is due to their technology differences. We simply don't know.

I'm not sure what you expect of Erich. He says he can't hear the difference. He hasn't trashed the product. I'm sure he has an open mind (along with the rest of us). Like I said before none of us should judge these under an uncontrolled and non-indicative test. I have no dog in this fight and I assure you I will do my best to give them a real test.

Remember, there are a number of other respected designers who chose the DE250 for their designs. I can think of Wayne Parham and Earl Geddes. I can't speak for them and their reasons for choosing it. Maybe they were not aware of the BMS or it didn't make business sense. Or maybe they felt the B&C was as good or better.

Ultimately I'd suggest being patient until a reliable test can be performed.
post #428 of 492
Quote:
Having said that, I have learned something else over the past year. Customers can also be interested more in something just because of price, different brand, or newness.....regardless of data.

Quote:
Originally Posted by Jack Arnott View Post


Now he is bagging on the companyt, and if I am reading him right, is calling everyone who is buying the product in the group buy stupid for spending more money, just because it is a different brand and costs more.

Jack,

I think you are looking for reasons to be argumentative that really aren't there. I may have read something differently into that statement than you; but the one thing that I'm pretty sure wasn't implied was that anyone was stupid. He does have a valid point though that there are many here who have jumped on the "next big thing" bandwagon (multiple sealed drivers, etc.) regardless of whether it is the best choice out there. BMS could honestly be looked at in that light without insulting anyone. I didn't see any tests prior to placing my order, but did so for reasons that could easily have placed me in that camp.

At this point though, until valid tests have been performed, the best thing we have to go on is Erichs intially listening impressions. Is it the end all be all definitive answer, of course not. But I trust Erichs ears and experience. As I mentioned earlier, there are many things that contribute to making a great driver. Distortion, integration, etc all play a role in the overall performance.

I am very happy with my decision to purchase the 4550. Would I have been just as happy with the 360? Absolutely. Do I feel stupid and duped for paying more for the 4550, no way. Could I be placed in the bandwagon brigade, ummmm, probably. biggrin.gif
post #429 of 492
Quote:
Originally Posted by carp View Post

Wait, let me get this straight. You guys are doing a group buy of the compression driver that is used in the Noesis thus creating a Noesis for far cheaper?

Goddam*it. mad.gif

I hope you guys screw it up and it sounds like arse!! What's worse is I bet anything Kevin (mrsmithers) is going to build one and then I'll have to hear it compared to the Noesis. He'll tell me it cost 50 bucks per speaker and then I'll go start the car in the garage with the door closed and take a nap in the back seat.




LALALALALALA... *this thread doesn't exist* .... LALALALALALALA




Who am I kidding - subscribed. frown.gif


Seriously though, after I get my SI subs built I should never come back to AVS again. EVAH!!!!!!!!!!!!


just started reading this thread --- this made me chuckle!
post #430 of 492
I don't think those of us that participated in this would have been swayed in or out of our purchasing decisions. I own both dna-360s and now BMS-4550s, as I know they will both perform exceptionally well. I'm interested in building out speakers with both drivers, and my subjective listening decides on if I notice a difference or like one better than the other. Its still way too early for this. In a few months time once we all have our builds done, that would be a good time to compare tests and opinions. As far as gaining new BMS customers, I'd say this was a success.

I would have even purchased a pair of 4594 coaxials if one of these fine speaker designing gentleman created a crossover and design incorporating them in a kit that I liked. I may still do so in the future. The price is just a little too out of my budget to have jumped on them blindly at this time.

I don't see anything wrong with the preliminary test one person did on just a 4550. If anything, it's actually favorable to BMS being that it measured so well, and we haven't even started with speaker designs yet.

We've only just begun smile.gif
post #431 of 492
Quote:
Originally Posted by Erich H View Post

This could be the first time in history that someone has said "This product sounds great and performs pretty much just like this other great sounding product".......and somehow ruffles feathers. wink.gif

Hi Erich,
What is ruffling my feathers is not that you say you can't hear any difference between them but that you are calling the BMS a clone, when in fact it has been around longer than the DE250.
And that I can't tell whether you are just yanking my chain by calling it a clone, and ignoring that they have very dissimilar builds, or if you are just being obtuse.
post #432 of 492
Quote:
Originally Posted by coctostan View Post

Thanks Jack. I appreciate the effort. I understand it can be difficult to find actual tests.
Quote:
Originally Posted by Erich H View Post

It's strange that they wouldn't compare poly to poly because the DE250 has been around long enough to compare it to.
Quote:
Originally Posted by cookieattk View Post

overly dramatic are we now ...... first off your testing a titanium dome vs a poly 2nd its not a 4550 and a de250 so it really has no relevance to anything here other then a $250 cd is better then a $170 one.

As I stated above, the test was done by a university. Not by BMS.
It was harvested from an AES paper.
IIRC the project was started to show the differences between dome tweeters, and compression drivers.
And that compression drivers have lower IM distortion. This particular page happens to compare the BMS and B&C drivers.
I of course have no control over what drivers the university chose. I am guessing that BMS was either asked to give them this particular driver, or some of their choosing.
I am not sure which. Three BMS drivers were mentioned in the tests.
Edited by Jack Arnott - 4/7/13 at 11:32pm
post #433 of 492
Quote:
Originally Posted by Archaea View Post

just started reading this thread --- this made me chuckle!

Haha, I completely forgot about posting that. Evidently I didn't know at the time how expensive the specific BMS CD is that is in the Noesis.

Well, my SI subs are done so it looks like I didn't take my own advice.
post #434 of 492
Quote:
Originally Posted by Jack Arnott View Post



As I stated above, the test was done by a university. Not by BMS.
It was harvested from an AES paper.
IIRC the project was started to show the differences between dome tweeters, and compression drivers.
And that compression drivers have lower IM distortion. This particular page happens to compare the BMS and B&C drivers.
I of course have no control over what drivers the university chose. I am guessing that BMS was either asked to give them this particular driver, or some of their choosing.
I am not sure which. Three BMS drivers were mentioned in the tests.

I don't think anybody is saying you are being dishonest just that this test doesn't hold much weight given the fact we already know the DE250 sounds much better than the DE500. I don't think it was the product of funny business. Now if this AES paper tried to show some correlation/causation from BMS's technology vs more traditional compression drivers that would be interesting.

This is not an anti-BMS group...a bunch of us did buy. We also targeted the 4550 and DE250/DNA360 when designing the SEOS-12/15/18 which Erich sells. The reason for this was because we could only choose 1 exit angle to match and the 4550 and DE250 were two of the leading CDs available at a reasonable price.

I look forward to comparing CDs. I have no bias at all (besides reading other's prior impressions which I don't buy anyway). I don't think anybody is taking Erich's quick comparison and impressions as gospel.
post #435 of 492
Quote:
Originally Posted by coctostan View Post

This is not an anti-BMS group...a bunch of us did buy. We also targeted the 4550 and DE250/DNA360 when designing the SEOS-12/15/18 which Erich sells. The reason for this was because we could only choose 1 exit angle to match and the 4550 and DE250 were two of the leading CDs available at a reasonable price.

That's exactly right. iirc, the first time the 4550 was mentioned, it was in reference to drivers with exit angles that work with the SEOS. The DE250 is 14 degrees, 4550 is 14.6, etc. It was never this sounded better than that, that I recall. I went with the 4550 and BMS for the simple reason that Auto-Tech uses them for testing most of their waveguides, SEOS, Tractrix, Le Cleac'h, etc. I missed this GB unfortunately, but I'm also interested in many other drivers (including the dna-360, B&C, Beyma, Radian)...it's all in the timing with diy and the weight of my wallet. tongue.gif
post #436 of 492
Good Morning Everybody,

I realize that you all know Erich much better than I do.
I only have this one experience to go by. I now realize that I feel angry.
This stems from Erich emailing BMS directly and claiming to be ready to place an order over $15,000.
At this point I also felt fear that Erich was trying to scuttle the group buy, but it moved forward.

He also did not reply to my email about placing the order.

So then I felt that Erich was either stupid and not paying attention for not knowing that I was the US distributor, or conniving for trying to go behind my back.
So when he now posts that the 4550 is nothing but a clone, I am left with these two thoughts. That he was either not paying attention, or is trying to subvert me and BMS.

Erich, I am also feeling anger that you are now calling BMS liars.

If you have questions that I have not answered, please repost them.
I just wanted you all to know how I felt before moving forward.

I hope you enjoy your drivers.

Regards, Jack
post #437 of 492
Quote:
Originally Posted by Erich H View Post

I really shouldn't have tested them or given an opinion. But you have to admit, it's quite strange when people get a little bent that someone said "These are all great and pretty much sound the same". wink.gif Hopefully no one thought another B&C "clone" by a well known manufacturer was going to split atoms or something? BMS didn't start from the ground up to create something that spanks the DE250. They're designed to be nearly identical.....which they are.

This is the post I referenced above.
I am sure you can all read it with a clearer mind than me. I have my predisposed opinions now.
post #438 of 492
Jack,

Maybe you should take this private as even though you feel wronged you are not doing yourself any favors. Erich could also make a real stink about having to pick up the items which were supposed to be delivered directly to him he but he has taken the high road and providing a real service to the DIY community. Who do you think the majority of people on here are going to take sides with, the guy who is profiting or the guy who is doing a real BIG favor for the DIY community and not asking for compensation?

Don't air your dirty laundry in public Jack, it only makes you stink.
post #439 of 492
Quote:
Originally Posted by mjaudio View Post

Jack,

Maybe you should take this private as even though you feel wronged you are not doing yourself any favors. Erich could also make a real stink about having to pick up the items which were supposed to be delivered directly to him he but he has taken the high road and providing a real service to the DIY community. Who do you think the majority of people on here are going to take sides with, the guy who is profiting or the guy who is doing a real BIG favor for the DIY community and not asking for compensation?

Don't air your dirty laundry in public Jack, it only makes you stink.

Sorry if my feelings are dirty laundry to you.
I felt that I owed an explanation to the community of my feelings, and how they were affecting my answers of late.
post #440 of 492
Quote:
Originally Posted by Jack Arnott View Post

This is the post I referenced above.
I am sure you can all read it with a clearer mind than me. I have my predisposed opinions now.

Jack, I did miss Erich's post. Yes, Erich is incorrect in saying that the BMS is some sort of clone of the B&C. BMS is certainly unique with its ring radiator design vs the more conventional dome diaphragm of the DE250/DNA360. The BMS drivers are not clones of the B&C or any other driver (short of having a lineage dating back to the first compression drivers).

The 4550 does have similar specs such as FR, bandwidth, power handling, diaphragm material etc. How they differ in home use performance remains to be seen.
post #441 of 492
Quote:
Originally Posted by mjaudio View Post

Jack,

Maybe you should take this private as even though you feel wronged you are not doing yourself any favors. Erich could also make a real stink about having to pick up the items which were supposed to be delivered directly to him he but he has taken the high road and providing a real service to the DIY community. Who do you think the majority of people on here are going to take sides with, the guy who is profiting or the guy who is doing a real BIG favor for the DIY community and not asking for compensation?

Don't air your dirty laundry in public Jack, it only makes you stink.

Also I should point out more clearly that any problems, real or perceived, may be only on my end.
As I said, you all know Erich better than me.

Only wanted you to know how it has been affecting my answers.
post #442 of 492
Thread Starter 
I don't even know what to say in this thread anymore...hence why I haven't posted in it in days. I have written a response and deleted it about 100 times today. I can't speak for anyone else, but I feel sorry that this thread/buy has turned into this. It started with the best of intentions, and has turned into crazyness. I have chatted with Erich many times, and I feel confident that his comment is not meant as BMS is a copycat company, but that both drivers are pretty much the same in measurement and performance. I can also say that I have experienced both DNA drivers and BMS, and they are both great! I kind of want to say more, but don't feel it to be appropriate to say negative things.
post #443 of 492
Quote:
Originally Posted by Jack Arnott View Post

This stems from Erich emailing BMS directly and claiming to be ready to place an order over $15,000.
At this point I also felt fear that Erich was trying to scuttle the group buy, but it moved forward.

He also did not reply to my email about placing the order.

So then I felt that Erich was either stupid and not paying attention for not knowing that I was the US distributor, or conniving for trying to go behind my back.
So when he now posts that the 4550 is nothing but a clone, I am left with these two thoughts. That he was either not paying attention, or is trying to subvert me and BMS.

Jack, you are looking into this way more than you should.

As mentioned half way through all of this, I had NO IDEA what was going on with the group buy. I didn't know who ordered what, when it was going to be done, or that you were 'the' US distributor. I merely offered to help ship things.

When you and others mentioned that this entire group buy was about to go bust because some people were going to pull out.......I tried to step up and keep that from happening. Again, as mentioned earlier, I told the designers that if the BMS was some magical compression driver, then we might consider using them in the Alpha series. So when I saw the group buy had a chance to be killed off, I contacted BMS and said I currently use B&C products but might want to also use BMS products in the future.......this is 100% true if there was a need. I told them I understand minimum orders and that I would not put in an order under $15k.

When you emailed me, I clearly told you that. So I don't understand what the issue is.

How many times do I need to say that I like the way they sound and that they're nice drivers? But I said they sound pretty much just like the DE250. What is so wrong with that? I clearly mentioned that at first I noticed more low end and less in the midrange for them. But once the volume was equalized, they were both very smooth and clean sounding with no big benefits of either one. How is that bad?? It's my opinion. Like Coctostan said, it's not the gospel. It's my opinion that once leveled in a speakers crossover, they will sound the same. Sorry that bothers you.



As for me saying these are all clones, they are. If a well known name brand company puts out a product with the same body, and same general make up, and the same diaphragm material......I consider them all pretty much clones of each other. As long as they are a good company, they're likely to all sound extremely similar......which they do. I don't care who came out with what first. Put them all together, test them all, they're basically all clones of each other.

As for my take on BMS. I didn't call them liars. I said that even though they are a good company, and put out great products (more compliments from me), their marketing department puts up specs like Pyle does. I'm not going to get in a debate whether a poly diaphragm in a 1" driver has a remotely usable response of 500hz (look at their own charts), or if it can handle 450 watts, even crossed at their recommendation. If they would like to prove me wrong, I will make up a basic 800hz crossover, and put my Behringer EP2500 on it and see how long it lasts listening to this:

http://www.youtube.com/watch?v=c2Fnet0y9Ts

Rock on gentlemen. biggrin.gif
post #444 of 492
Thread Starter 
Quote:
Originally Posted by Erich H View Post

Jack, you are looking into this way more than you should.

As mentioned half way through all of this, I had NO IDEA what was going on with the group buy. I didn't know who ordered what, when it was going to be done, or that you were 'the' US distributor. I merely offered to help ship things.

When you and others mentioned that this entire group buy was about to go bust because some people were going to pull out.......I tried to step up and keep that from happening. Again, as mentioned earlier, I told the designers that if the BMS was some magical compression driver, then we might consider using them in the Alpha series. So when I saw the group buy had a chance to be killed off, I contacted BMS and said I currently use B&C products but might want to also use BMS products in the future.......this is 100% true if there was a need. I told them I understand minimum orders and that I would not put in an order under $15k.

When you emailed me, I clearly told you that. So I don't understand what the issue is.

How many times do I need to say that I like the way they sound and that they're nice drivers? But I said they sound pretty much just like the DE250. What is so wrong with that? I clearly mentioned that at first I noticed more low end and less in the midrange for them. But once the volume was equalized, they were both very smooth and clean sounding with no big benefits of either one. How is that bad?? It's my opinion. Like Coctostan said, it's not the gospel. It's my opinion that once leveled in a speakers crossover, they will sound the same. Sorry that bothers you.



As for me saying these are all clones, they are. If a well known name brand company puts out a product with the same body, and same general make up, and the same diaphragm material......I consider them all pretty much clones of each other. As long as they are a good company, they're likely to all sound extremely similar......which they do. I don't care who came out with what first. Put them all together, test them all, they're basically all clones of each other.

As for my take on BMS. I didn't call them liars. I said that even though they are a good company, and put out great products (more compliments from me), their marketing department puts up specs like Pyle does. I'm not going to get in a debate whether a poly diaphragm in a 1" driver has a remotely usable response of 500hz (look at their own charts), or if it can handle 450 watts, even crossed at their recommendation. If they would like to prove me wrong, I will make up a basic 800hz crossover, and put my Behringer EP2500 on it and see how long it lasts listening to this:

http://www.youtube.com/watch?v=c2Fnet0y9Ts

Rock on gentlemen. biggrin.gif

Well put sir!
post #445 of 492
Quote:
Originally Posted by Jack Arnott View Post

Sorry if my feelings are dirty laundry to you.
I felt that I owed an explanation to the community of my feelings, and how they were affecting my answers of late.

I understand trying to defend the product you represent but to expose the end users to the drama on a public forum doesn't seem productive. I was really just commenting as I hoped you would reconsider and take it private to resolve any problems, to do it publicly can do more harm than good for you.

If Erich was just a rep from B&C who none of us knew then I would grab the popcorn and watch you 2 duke it out wink.gif Erich has been around here for a long time though first as a DIY'er like the rest of us then began helping on organizing Group Buys. I have been fortunate enough to use some of his flat packs and my only regret is that Erich didn't set that up sooner, I would have saved thousands on tools!

Can't we all just get along biggrin.gif
post #446 of 492
Quote:
Originally Posted by Erich H View Post

Jack, you are looking into this way more than you should.

Quite likely possible
Quote:
Originally Posted by Erich H View Post

I didn't know who ordered what, when it was going to be done, or that you were 'the' US distributor.

Exactly. Even though I told you on the phone, and wrote it in this thread, I failed to communicate this to you.
Quote:
Originally Posted by Erich H View Post

As for me saying these are all clones, they are.

As such, I also feel that despite my best efforts, I have not communicated to you that the BMS is not a conventional dome driver.
That it is a ring radiator design.

That is why I do not like you calling it a clone.

Regards, Jack
post #447 of 492
Quote:
Originally Posted by Jack Arnott View Post

Quite likely possible
Exactly. Even though I told you on the phone, and wrote it in this thread, I failed to communicate this to you.
As such, I also feel that despite my best efforts, I have not communicated to you that the BMS is not a conventional dome driver.
That it is a ring radiator design.

That is why I do not like you calling it a clone.

Regards, Jack

do you happen to have a pic of the inside of a coax or 4550 ? just wondering what a ring radiator looks like !
post #448 of 492
post #449 of 492
Quote:
Originally Posted by cookieattk View Post

do you happen to have a pic of the inside of a coax or 4550 ? just wondering what a ring radiator looks like !

Hi Cookieattk, thanks, even if it is just "squirrel".

And cool about the headphones. I was not aware of these.




In the first one, the VC is in the center of the diaphragm. The sound goes through the slots on the back of the diaphragm.
On the second picture if you will notice there are ribs in the plastic. These are divisions between the slots. So each slot has its own path to the center.
The sound goes into the center, by a small phase plug, and out through the center ring.

The center ring also acts as a centering device. Positioning the voice coil in the gap properly.

The diaphragm is not flat, it is slightly raised in the middle at the voice coil. In the first picture you can see some glare in the lower left that kind of defines this a little.

Regards, Jack
post #450 of 492





These are from a 4592. Same diaphragms as 4594, but different phase plug and exit angle.

The mid diaphragm is the same as the 4550. The sound goes off the back. Here you can see the edges of the dividers as they taper off to meet the phase plug.
The high frequency diaphragm is a little different. In this case the sound comes off the front.
It sits at the very back, and is held in place by the phase plug.
There is no HF diaphragm in the cut away, but you should be able to see the ring where it goes.
The VC is on the back side, and the gap behind that. The sound joins the mid frequencies at the phase plug.

On the mid diaphragm I tried to shoot at an angle to show that there are windings on both the inside and outside of the former.
Don't know if that came through or not.

Regards, Jack
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