My kids are 3 and 7 - and are absolutely EXCITED for this project!!I just came back in town this morning and got off of work at 4. A few minutes later, two of the woofers are propped up and connected to the EP2000. I'm running them with a 50Hz line level lowpass from PE (I think it's around 12-18db/oct slope), no high pass on the amplifier.
First impressions: WOW! They put to shame the two ported towers in terms of musicality. Very good low end extension and blend well to the current 3-way OB (sans the 12s) which runs without a highpass filter on the low end. I think there's a dip somewhere between 80-150ish hertz - just by ear. The bass boost is set to +1 on the receiver. I ran out of wood and room for all four so output was slightly limited, but still very admirable for just having the woofer sit there on the floor. Pretty amazing to say the least.
For now I'm thinking about building up a *cheap* baffle for the woofers and integrating my current 3-way set until funds become more available and more research is done for a different driver set, or just magnet mount them (sets of two) with no baffle for the time being.
I'm still leaning very much towards the AN drivers for some reason - super12's or super15's. There's a few threads that I read through with impressions of the ANs on an OB are pretty good. I only fear for the lack of excursion for my listening volume tastes.
On the other hand, there's a Peerless woofer that might be a good candidate: Peerless 830869 - Nomex Cone HDS. It looks like it could be usable to 2kHz. Paired with maybe a Vifa XT25TG30, which looks good down to about 1kHz. A waveguide may not be needed due to the extension of the Vifa tweeter.
Thoughts? Driver suggestions, as always, are welcome.
And of course obligatory pictars!
An externally hosted image should be here but it was not working when we last tested it.
Build quality looks alright for 120 bucks/driver. Not the best I've seen. There's some what appears to be glue residue on the back of the cones - very thin layer. There's a very very small chip in one of the magnets around the outside (of the two I opened).
I would try this: http://www.diyaudio.com/forums/multi-way/159731-beautiful-swingin-speaker-12.html#post2672403 for mounting the woofers for start..
also check this thread: http://www.diyaudio.com/forums/multi-way/175745-three-way-nude-swinging-dipole-thread.html
there are tweeters that will go low enough to be used with 8" (dayton reference) without waveguide, but the reason I suggested waveguide is that you get very good dipole-like dispersion control
or you can just use dayton RS225 + RS28A and "copy" Linkwitz's orion..
also check this thread: http://www.diyaudio.com/forums/multi-way/175745-three-way-nude-swinging-dipole-thread.html
there are tweeters that will go low enough to be used with 8" (dayton reference) without waveguide, but the reason I suggested waveguide is that you get very good dipole-like dispersion control
or you can just use dayton RS225 + RS28A and "copy" Linkwitz's orion..
And of course obligatory pictars!
Good to see you've got the speakers:TV size ratio about right.
MCM 21" woofer
Siruis815...
Great project you have in the works! Thanks for sharing and pictures.
I am very interested in your take on the 21". I also purchased them. Unfortunately, they were not close to advertised specification. This was just over a year ago, so you likely have received a later, different production run.
Do you have the ability to measure T/S values? It was the QE that was way off with my units. Way, Way high, which drove the QTS to something like 1.7. FS and so forth were close to spec. It was like the magnets were defective or under charged. Build quality though was very good for the price.
So the true efficeincy was around 88 db/watt, which is not remotely close to the advertised specification. I did write MCM and they responded saying they would look into the situation and get back to me. After a couple of follow ups from my end I never heard anything back from them.
Of course hope your set of drivers are spot on and work out as planned.
John
Siruis815...
Great project you have in the works! Thanks for sharing and pictures.
I am very interested in your take on the 21". I also purchased them. Unfortunately, they were not close to advertised specification. This was just over a year ago, so you likely have received a later, different production run.
Do you have the ability to measure T/S values? It was the QE that was way off with my units. Way, Way high, which drove the QTS to something like 1.7. FS and so forth were close to spec. It was like the magnets were defective or under charged. Build quality though was very good for the price.
So the true efficeincy was around 88 db/watt, which is not remotely close to the advertised specification. I did write MCM and they responded saying they would look into the situation and get back to me. After a couple of follow ups from my end I never heard anything back from them.
Of course hope your set of drivers are spot on and work out as planned.
John
I wish I had something to measure the actual T/s parameters..alas with an OB project, a very high QTS isn't really a bad thing so not too worried here. I definitely could tell that the efficiency isn't anywhere close to what they advertise as I need quite a bit of power to drive them. I'm probably going to have to upgrade to an EP4000...I plan on doing some experimentation with the T-bass circuit as well.
Worked on the magnet mounts some more this morning - one side should be done. I'm going to assemble it in a few and then report back.
Also to all: Thanks for following my build and the recommendations! Some real knowledgeable guys on this forum.
I played around with some settings on the receiver after connecting up all 4 woofers. End results: +2 Bass Boost, subwoofer crossover at 170hz. This fills in the midbass very well.
I'm assuming (without measurements) that the sensitivity of the woofer is much greater in the midbass than the low end so setting them play up to 170Hz and the bass boost (at the receiver) along with the 50Hz line level low-pass results in a very good blend to the 2-way.
I'll have to try and take another picture tonight. My router bit failed part way through the second magnet mount support so one set is just leaning against the wall. :/
I'm assuming (without measurements) that the sensitivity of the woofer is much greater in the midbass than the low end so setting them play up to 170Hz and the bass boost (at the receiver) along with the 50Hz line level low-pass results in a very good blend to the 2-way.
I'll have to try and take another picture tonight. My router bit failed part way through the second magnet mount support so one set is just leaning against the wall. :/
Played around with the entire system some more today. The EP2000 definitely runs out of steam before the MCMs do. And I must say that I missed the ported towers for the very bottom end So I have a feeling an EP4000 is on the way before too long.
I also currently like the way the old 3-way sounds with the MCMs so I'll be keeping that around for a while until I can decide on new drivers and experiment with those.
I'm not 100% happy with the magnet mounts I made (didn't end up taking a picture). I'll be redoing that portion soon and also adding the 3-way to a baffle on top of the MCMs, probably tilted down a bit due to the height.
On a side note: Anybody ever use compression drivers for Hifi use? Maybe a Selenium D220Ti w/ HL14-25 Waveguide setup? Also - what about pro-audio midbasses?
So I have a feeling an EP4000 is on the way before too long. I also currently like the way the old 3-way sounds with the MCMs so I'll be keeping that around for a while until I can decide on new drivers and experiment with those.
I'm not 100% happy with the magnet mounts I made (didn't end up taking a picture). I'll be redoing that portion soon and also adding the 3-way to a baffle on top of the MCMs, probably tilted down a bit due to the height.
On a side note: Anybody ever use compression drivers for Hifi use? Maybe a Selenium D220Ti w/ HL14-25 Waveguide setup? Also - what about pro-audio midbasses?
I would suggest:
BC DE250-8 (polyimide diaphragm, no metal, no break-up): B&C DE250-8 1" Polyimide Horn Driver 8 Ohm 2/3-Bolt 294-605
With SEOS: SEOS? Products DIY Sound Group
Midbass: AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.
(I use, BC DE250-8, SEOS-15 and AE LO15 in OB)
By the way > Nice woofers!!
I use DE250 too, it is good driver for home use, but the cheaper selenium should be good too.. definately go with different horn - SEOS is nice, if you need cheaper go with 18sound XT1086. there are many nice 10" pro drivers that will work fine, I would definately consider this approach: http://www.diyaudio.com/forums/multi-way/195870-el-cuerno.html
this could be nice 3way with well controled directivity
this could be nice 3way with well controled directivity
Thanks for the feedback. I've looked at the Seos horns and the 18sound ones. Wish they were more circular such as the Autotech OS12?
Also - I just re-read one of the waveguide shootouts. Apparently, the Selenium 220Ti with the 10" Dayton waveguide = "impressive".
Also - I just re-read one of the waveguide shootouts. Apparently, the Selenium 220Ti with the 10" Dayton waveguide = "impressive".
Add'l - driver choices have been narrowed down to the B&C 10CL51 ($105) and the Celestion TF1020 ($70). Specs look fairly close with the Celestion a little smoother but with only 2mm excursion.
Okay baffles and new magnet mounting system is almost done - done enough to at least stand up and see what the differences are compared to the baffleless setup. Much more efficiency with the baffle. I think it also looks a bit better I'm happy so far.
The OS-12s are gorgeous. I'll be painting them black (they are currently white).
I'm going on vacation to Germany in a few weeks so progress will likely be slow. Next on the list is going to be the midrange and compression drivers along with gathering some caps, coils, and resistors to play with.
On to pics (and yes I know they are way too close to the wall - that will change)
I'm happy so far.The OS-12s are gorgeous. I'll be painting them black (they are currently white).
I'm going on vacation to Germany in a few weeks so progress will likely be slow. Next on the list is going to be the midrange and compression drivers along with gathering some caps, coils, and resistors to play with.
On to pics
(and yes I know they are way too close to the wall - that will change)
Mini update - this build is NOT dead! I've changed the FMOD filters to 30Hz lowpass (found out they were 50s about a month ago) - much better. I have the woofers playing all the way down (no highpass) - bass set to -2 on the receiver. Integration is even better with the 3-way OB.
The B&C mid is still on order - July 12th is the expected date. Waveguides are getting painted. The DE250 will be ordered before too long as well.
I worked out some of the crossover yesterday using the no measurements guide sticky. I'll post it up later and of course feel free to provide some feedback.
PS - I personally hate rap music, but VIC's song "Get Silly" certainly puts a smile on my face as far as low end extension goes!
PSS - I measured the voltage output of the EP2000 playing a 30Hz tone at a very respectable volume, a good ways above normal listening and WAY above what anyone should play at 6AM. I came up with ~15Vrms with my fluke multimeter. About 56 Watts per channel. Not too inefficient after all?
I may be able to downsize the amplifier if I get a line driver to up the input voltage - seems like I'm running out of gain. I have a ART Cleanbox Pro to convert from RCA to XLR, however it and the amp are almost maxed on their gain. Seems like I'm just using the voltage gain of a very powerful amplifier to achieve relatively low power levels (compared to what it's capable of).
To compound the potential problem, the B&C drivers are even more sensitive than the 3way I have now(~84dB) (96dB for the B&C mid and 108.5 for the compression tweeter). L-Pad's usually do down to ~-8dB? I'm still planning on using the Sony receiver to power the set. Thoughts?
The B&C mid is still on order - July 12th is the expected date. Waveguides are getting painted. The DE250 will be ordered before too long as well.
I worked out some of the crossover yesterday using the no measurements guide sticky. I'll post it up later and of course feel free to provide some feedback.
PS - I personally hate rap music, but VIC's song "Get Silly" certainly puts a smile on my face as far as low end extension goes!
PSS - I measured the voltage output of the EP2000 playing a 30Hz tone at a very respectable volume, a good ways above normal listening and WAY above what anyone should play at 6AM. I came up with ~15Vrms with my fluke multimeter. About 56 Watts per channel. Not too inefficient after all?
I may be able to downsize the amplifier if I get a line driver to up the input voltage - seems like I'm running out of gain. I have a ART Cleanbox Pro to convert from RCA to XLR, however it and the amp are almost maxed on their gain. Seems like I'm just using the voltage gain of a very powerful amplifier to achieve relatively low power levels (compared to what it's capable of).
To compound the potential problem, the B&C drivers are even more sensitive than the 3way I have now(~84dB) (96dB for the B&C mid and 108.5 for the compression tweeter). L-Pad's usually do down to ~-8dB? I'm still planning on using the Sony receiver to power the set. Thoughts?
Here's my initial plan for the xover:
The "other" solution would be to purchase the 2x4 minidsp (~100) and two Topping T amps (~75ea). From there I can do all the crossover and eqing I'd like. After all this is set, I can then come up with a "proper" passive setup.
Thoughts?
Thanks,
Ben K.
The initial 8R is to bring the system down ~6dB (unless I can solve the gain issue for the 21" woofers) with a new system Z of ~16ohms.
The crossover is set to about 1k @12dB/oct. I put in a -17dB L-pad for the tweeter (-12dB for its much higher efficiency and add'l -5db for baffle step/OB comp on the mid).
I put a -5dB baffle step at ~190Hz This *should* bring response flatter from there to the crossover frequency (if response will be close to EDGE OB predictions). This can be tweaked later.
The crossover is set to about 1k @12dB/oct. I put in a -17dB L-pad for the tweeter (-12dB for its much higher efficiency and add'l -5db for baffle step/OB comp on the mid).
I put a -5dB baffle step at ~190Hz This *should* bring response flatter from there to the crossover frequency (if response will be close to EDGE OB predictions). This can be tweaked later.
The "other" solution would be to purchase the 2x4 minidsp (~100) and two Topping T amps (~75ea). From there I can do all the crossover and eqing I'd like. After all this is set, I can then come up with a "proper" passive setup.
Thoughts?
Thanks,
Ben K.
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