The BMS group buy thread!!! - Page 13 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #361 of 492 Old 04-03-2013, 02:13 PM
AVS Special Member
 
bhazard's Avatar
 
Join Date: Nov 2006
Location: NY
Posts: 2,413
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 36
All good VC
bhazard is offline  
Sponsored Links
Advertisement
 
post #362 of 492 Old 04-03-2013, 02:29 PM
Member
 
MrSmithers's Avatar
 
Join Date: Jan 2012
Posts: 143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Kevin S is correct.
MrSmithers is offline  
post #363 of 492 Old 04-03-2013, 02:38 PM
Advanced Member
 
hometheaterdoc's Avatar
 
Join Date: Feb 2004
Location: Durham, North Carolina
Posts: 517
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 29
Mine is correct. I thought you were sending the crossovers separate so I didn't list it on my last post. We're all good on mine....

Shane
hometheaterdoc is offline  
post #364 of 492 Old 04-03-2013, 03:46 PM
Advanced Member
 
btinindy's Avatar
 
Join Date: Aug 2010
Posts: 830
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 52
Brian T is correct!
btinindy is online now  
post #365 of 492 Old 04-03-2013, 05:02 PM
AVS Special Member
 
countryWV's Avatar
 
Join Date: Aug 2011
Location: Huntington West Virginia
Posts: 1,339
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Liked: 139
countryWV is offline  
post #366 of 492 Old 04-03-2013, 06:37 PM
AVS Special Member
 
Raul GS's Avatar
 
Join Date: Feb 2003
Posts: 2,194
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 24
Same here.

Ignorance more frequently begets confidence, than it does knowledge. Charles Darwin
Raul GS is offline  
post #367 of 492 Old 04-03-2013, 07:40 PM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 274
Travis S is correct.

Achievement Unlocked

Psychotic Episode Averted

bass addict is online now  
post #368 of 492 Old 04-04-2013, 06:00 AM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
The quote for shipping the pallet to me is too high to justify. It's over $200.

I'm going to have to send one of the employees there today or tomorrow with one of my trucks.
Erich H is online now  
post #369 of 492 Old 04-04-2013, 08:26 AM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 274
Quote:
Originally Posted by Erich H View Post

The quote for shipping the pallet to me is too high to justify. It's over $200.

I'm going to have to send one of the employees there today or tomorrow with one of my trucks.

Without beating a dead horse any more; it is sad you are taking on this burden. Why don't you just ship it and bill all of us for the freight based on the percentage of order we placed. It's great you can send an employee, but time is money as well.

Achievement Unlocked

Psychotic Episode Averted

bass addict is online now  
post #370 of 492 Old 04-04-2013, 08:42 AM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
It's not really a problem worth worrying about. Just some drive time.

Who wants me to do a comparison test between the B&C DE250, Denovo DNA-360, Denovo DNA-350, Dayton PED250, and BMS 4550 once they arrive? biggrin.gif
Erich H is online now  
post #371 of 492 Old 04-04-2013, 08:53 AM
AVS Special Member
 
countryWV's Avatar
 
Join Date: Aug 2011
Location: Huntington West Virginia
Posts: 1,339
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Liked: 139
I do. You can use mine if needed.
Chris W
countryWV is offline  
post #372 of 492 Old 04-04-2013, 08:57 AM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 274
Quote:
Originally Posted by Erich H View Post

It's not really a problem worth worrying about. Just some drive time.

Who wants me to do a comparison test between the B&C DE250, Denovo DNA-360, Denovo DNA-350, Dayton PED250, and BMS 4550 once they arrive? biggrin.gif

Not me. I'll be pissed if the 360 performs better than the 4550. As is is now; ignorance is bliss. biggrin.gif

Achievement Unlocked

Psychotic Episode Averted

bass addict is online now  
post #373 of 492 Old 04-04-2013, 10:06 AM
Member
 
madlim's Avatar
 
Join Date: Nov 2010
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by Erich H View Post

It's not really a problem worth worrying about. Just some drive time.

Who wants me to do a comparison test between the B&C DE250, Denovo DNA-360, Denovo DNA-350, Dayton PED250, and BMS 4550 once they arrive? biggrin.gif

I do! I'm also interested in how the Dayton PED250 performs, have there been any published measurements of this driver?
madlim is offline  
post #374 of 492 Old 04-04-2013, 10:57 AM
AVS Special Member
 
Gorilla83's Avatar
 
Join Date: Aug 2011
Location: Delaware County, PA
Posts: 3,542
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 228 Post(s)
Liked: 394
Quote:
Originally Posted by Erich H View Post

It's not really a problem worth worrying about. Just some drive time.

Who wants me to do a comparison test between the B&C DE250, Denovo DNA-360, Denovo DNA-350, Dayton PED250, and BMS 4550 once they arrive? biggrin.gif

Yes please! Data/info is always welcomed. biggrin.gif
Gorilla83 is offline  
post #375 of 492 Old 04-04-2013, 11:09 AM
Advanced Member
 
Face2's Avatar
 
Join Date: Mar 2007
Location: Long Island, NY
Posts: 727
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 49
Quote:
Originally Posted by madlim View Post

I do! I'm also interested in how the Dayton PED250 performs, have there been any published measurements of this driver?
Don't get your hopes up too high.

Mike
Face2 is offline  
post #376 of 492 Old 04-04-2013, 03:13 PM
Advanced Member
 
Face2's Avatar
 
Join Date: Mar 2007
Location: Long Island, NY
Posts: 727
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 49
So what are the odds of another GB?

Mike
Face2 is offline  
post #377 of 492 Old 04-04-2013, 04:08 PM
AVS Special Member
 
bhazard's Avatar
 
Join Date: Nov 2006
Location: NY
Posts: 2,413
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 36
Quote:
Originally Posted by Erich H View Post

It's not really a problem worth worrying about. Just some drive time.

Who wants me to do a comparison test between the B&C DE250, Denovo DNA-360, Denovo DNA-350, Dayton PED250, and BMS 4550 once they arrive? biggrin.gif

Would love that.
bhazard is offline  
post #378 of 492 Old 04-04-2013, 05:06 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
Erich H is online now  
post #379 of 492 Old 04-04-2013, 05:14 PM
Advanced Member
 
cookieattk's Avatar
 
Join Date: Jun 2011
Posts: 567
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 59
Quote:
Originally Posted by Erich H View Post

I am in possession of the pallet. biggrin.gif

great news how long do u think its going to take for the waveguides ?
cookieattk is offline  
post #380 of 492 Old 04-04-2013, 05:30 PM
Advanced Member
 
Face2's Avatar
 
Join Date: Mar 2007
Location: Long Island, NY
Posts: 727
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked: 49
Quote:
Originally Posted by cookieattk View Post

great news how long do u think its going to take for the waveguides ?
Week to couple of weeks.

Mike
Face2 is offline  
post #381 of 492 Old 04-04-2013, 08:25 PM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 274
Quote:
Originally Posted by Erich H View Post

I am in possession of the pallet. biggrin.gif

Sweet. Now go dig up my extra trio of SEOS15's. tongue.gif

Achievement Unlocked

Psychotic Episode Averted

bass addict is online now  
post #382 of 492 Old 04-05-2013, 05:13 AM
AVS Special Member
 
Sibuna's Avatar
 
Join Date: Apr 2010
Location: Western NY
Posts: 2,089
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 172 Post(s)
Liked: 301
Quote:
Originally Posted by bass addict View Post

Not me. I'll be pissed if the 360 performs better than the 4550. As is is now; ignorance is bliss. biggrin.gif

lol
Sibuna is online now  
post #383 of 492 Old 04-05-2013, 04:39 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
I'm going to try and get most of this stuff packaged up this weekend if I can. There is one issue. The 4550's are in cartons of 6 or 8, but not in individual boxes, basically just raw drivers. I'll have to get some type of small box for those, or I can possibly just wrap them in some cardboard.

If you guys want, you can go ahead and send me a PM or email to let me know what you ordered and your address so I can start packaging things up and getting final weights.

You have the option of getting insurance on the package if you want. It's normally a few dollars extra, but that's on things that are around $300 or so. I've got no idea what FedEx would charge for insurance on the very expensive items.

This is going to be a tough call because I promise to package these things to take a real beating, and they aren't really fragile anyway. I think most of you guys have seen my packaging already, so chances are very good that they won't get damaged. The only issue might be if FedEx actually lost a package, but that hasn't happened to me yet. So that will be up to you.

I want to try and break even on this stuff, so if you pay the shipping with Paypal, there will be 3% added to it. But I don't mind if you send a check to save that 3%. Packing boxes are cheap and I'm not going to worry about the packing foam and things like that. And of course I'll do this in my spare time, so no worry on that.

I did a quick test of a 4550. Sadly I don't think there's a benefit. I'll post up some graphs tonight if I have time. I believe the 4550 was about 3db more efficient on the low end, but at least 3db less on the high end. They don't go any lower. The 3db difference isn't a benefit if they all have to be lowered down to the woofer. By my ear, and having heard hundreds of CD's, when I raised the volume of the DE250 by 3db, or lowered the volume on the 4550 by 3db, they sound pretty much the same. I'll do a bit more testing and listening tonight. The curve of the 4550 might be easy to work with in a crossover though.

They sound good, so don't worry about that. I don't hear anything bad during testing.
Erich H is online now  
post #384 of 492 Old 04-05-2013, 05:39 PM
AVS Special Member
 
bass addict's Avatar
 
Join Date: Dec 2003
Location: A padded room
Posts: 3,944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked: 274
Quote:
Originally Posted by Erich H View Post


I did a quick test of a 4550. Sadly I don't think there's a benefit. I'll post up some graphs tonight if I have time. I believe the 4550 was about 3db more efficient on the low end, but at least 3db less on the high end. They don't go any lower. The 3db difference isn't a benefit if they all have to be lowered down to the woofer. By my ear, and having heard hundreds of CD's, when I raised the volume of the DE250 by 3db, or lowered the volume on the 4550 by 3db, they sound pretty much the same. I'll do a bit more testing and listening tonight. The curve of the 4550 might be easy to work with in a crossover though.

They sound good, so don't worry about that. I don't hear anything bad during testing.

Well I know it's purely subjective and not anything concrete, but your initial impressions leave me a little disconcerted. Fortunately these weren't much more than the others, and I still have high hopes for them, but I was hoping for a "heavens parting angelic singing" sort of initial impression. biggrin.gif

Achievement Unlocked

Psychotic Episode Averted

bass addict is online now  
post #385 of 492 Old 04-05-2013, 07:14 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
I'm retesting all the models together right now. There's nothing wrong with the 4550 at all. It's smooth and sounds good. But it doesn't extend lower. It does extend higher though, but none of us here can hear up around 19khz.

I'm going to go back down and do my listening test on both. That's pretty much where I let the OmniMic run a continuous loop of the typical whhhhhoooooorrrrppp, whhhhhoooooorrrrppp, whhhhhoooooorrrrppp for a couple minutes, then quickly switch to the next volume adjusted model to see if there is any noticable differences. biggrin.gif

I wouldn't mind opening one up and looking it over, but they aren't mine, so I'm not going to.
Erich H is online now  
post #386 of 492 Old 04-05-2013, 08:37 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
Frequency responses for all four compression drivers on the SEOS-12. These were all tested using the same power. I like to use red and blue when testing only 2 drivers, so a blue line on one graph might not be the same driver on another graph. Sorry, it is what it is. Of course if you look under each graph it will tell you which driver goes with what color for that particular test.

The PE driver might be closer related to the Selenium which I haven't tested. It is thinner than the other 3 tested here.

DE250 and PED250:



DE250 and DNA360:



DE250 and BMS4550:



DNA360 and BMS4550:

Erich H is online now  
post #387 of 492 Old 04-05-2013, 08:39 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
In the next photos I tried leveling out the compression drivers on the lower end to get a closer comparison across the board. At first I brought down the BMS 2.5db.

BMS4550 and DE250 leveled:



BMS4550 and DNA360 leveled:



BMS4550, DNA360, and DE250 leveled:



BMS4550, DNA360, DE250, and PED250 leveled:






I thought taking the BMS down 2.5db was okay when comparing with the DE250. But after looking at just the BMS4550 and DNA360 leveled, I wondered if lowering the BMS 2.5db was a little too much to get a good comparison. So I took it down 1.5db which might make it easier to compare. The low end is pretty much the same.

BMS4550 (lowered 1.5db) and DNA360:

Erich H is online now  
post #388 of 492 Old 04-05-2013, 08:57 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
Listening comparisons......

I don't listen to any of these straight on looking down the throat of the waveguide.

Keep in mind that I've heard hundreds of DNA-360's and DE250's at the same exact volume for a year. When I first hooked up the BMS I could hear the difference between it and the other 2. That was before looking at the screen. At first I thought the BMS had a stronger low end just by the way it sounded. I was able to pick up on the difference pretty easy. I listened to it for a while and could tell the lower frequencies were stronger than it's mid frequencies. You can see this in the response. It does not sound bad at all.

To get a better comparison between these, I would listen to one for a while (yes, just the standard test tone over and over). Then quickly switch to the next and adjust the volume by 2db to level them out.

With no crossovers being used and everything at the same listening volume, the lower frequencies on the BMS sound just like the 250 and 360. I can hear the frequency dip from 5khz to 15khz on the BMS. But one reason is because I've been hearing the flatter DE250 and DNA-360 for so long. Of course the dip is the main reason why the lower frequencies stood out more in the BMS when I first started listening.

In real world comparisons, and after a crossover was used to level the DE-250, DNA-360, and BMS-4550 to the woofer, I do believe these would sound pretty much identical in their lower frequencies. Yes, I can hear the dip in the BMS, but no one listens test tones. cool.gif And anyone doing the crossover work on would be shooting to level everything. So in the end, they're all pretty much the same.
Erich H is online now  
post #389 of 492 Old 04-05-2013, 09:20 PM
Advanced Member
 
John_E_Janowitz's Avatar
 
Join Date: Mar 2001
Location: Green Bay, WI USA
Posts: 849
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 41
Hi Erich, just a few things to note here. How low the compression drivers play is a function of the length of the waveguide and mouth area. Unless there are huge mass differences, or one has a very long throat inside the CD itself, the low end corner will be nearly the same. TAD compression drivers had a very long internal throat that often gave them a large advantage vs other compression drivers. Also, if you could change your scale would give a much better visualization as well. At 5dB per division it makes everything seem much less significant. If you went to 2dB per division it makes it much easier to see the differences.

If you are trying to show a fair comparison you don't want to change the levels on the BMS to bring it back down. All compression drivers are going to require some EQ to be flat so the curve shape has little relevance in terms of how it sounds in the end. It is efficiency and distortion that you should be concerned with in the comparison. The 4550 seems to be much more efficient than the DE250 in the first comparison you show. If you have 2.5dB more efficiency through a majority of the passband, that means you only need about 60% of the power to get the same output level over that region. This is huge in terms of lowering distortion and providing overall headroom.

John E. Janowitz
Acoustic Elegance, LLC
"Learn from the mistakes of others... you can't possibly live long enough to make them all yourself"
John_E_Janowitz is offline  
post #390 of 492 Old 04-05-2013, 10:06 PM
AVS Special Member
 
Erich H's Avatar
 
Join Date: Dec 2007
Location: Cincinnati OH
Posts: 5,432
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 350 Post(s)
Liked: 646
Quote:
Originally Posted by John_E_Janowitz View Post

Hi Erich, just a few things to note here. How low the compression drivers play is a function of the length of the waveguide and mouth area. Unless there are huge mass differences, or one has a very long throat inside the CD itself, the low end corner will be nearly the same. TAD compression drivers had a very long internal throat that often gave them a large advantage vs other compression drivers. Also, if you could change your scale would give a much better visualization as well. At 5dB per division it makes everything seem much less significant. If you went to 2dB per division it makes it much easier to see the differences.

If you are trying to show a fair comparison you don't want to change the levels on the BMS to bring it back down. All compression drivers are going to require some EQ to be flat so the curve shape has little relevance in terms of how it sounds in the end. It is efficiency and distortion that you should be concerned with in the comparison. The 4550 seems to be much more efficient than the DE250 in the first comparison you show. If you have 2.5dB more efficiency through a majority of the passband, that means you only need about 60% of the power to get the same output level over that region. This is huge in terms of lowering distortion and providing overall headroom.

Yes, I fully understand your first paragraph. That's why last month I said I doubt the BMS could be crossed lower than the other 2. But of course there is more to it than the internal throat. I've got clones here that are pretty much identical to each other. But they can't be crossed as low each other. The diaphragm make up, rear chamber, and the foam inside also plays a pretty big roll.

With regards to efficiency, as mentioned I think it's closer to a 1.5db difference, not 2.5db. I posted both charts to show the differences. I simply leveled them out on the 2nd ones to show that the BMS can't really be crossed over any lower than the DE250 or DNA360 on the same horn or waveguide.

Distortion on all 3 of these models is extremely low to start with. I don't think adding the small amount of power to go up 1.5db on a compression driver is going to make a difference.

I should say, because the distortion is already extremely low, at what point on these better CD's is it even be worth talking about? What power would the CD need before worrying about distortion on any of them, and what volume would the speaker be at? 115db, 120db, 125db? By then, 1.5db isn't really a concern because their ears might already be bleeding, let alone actually trying to compare the distortion of 2. smile.gif

In the end, with a crossover designed for each model, all 3 of these are pretty much identical.
Erich H is online now  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off