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Multi-Way Conventional loudspeakers with crossovers

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Old 19th April 2012, 12:36 AM   #21
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I'll have a look around. Thank you for your input.

And as a small teaser via MMS:

Click the image to open in full size.
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Old 19th April 2012, 11:07 AM   #22
sumacSK is offline sumacSK  Slovakia
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man you have small children! or is the spaker that big?!?
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Old 20th April 2012, 01:52 AM   #23
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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!

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

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).
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Old 21st April 2012, 01:08 AM   #24
sumacSK is offline sumacSK  Slovakia
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I would try this: Beautiful Swingin' Speaker for mounting the woofers for start..
also check this thread: the three way nude swinging dipole thread
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..
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Old 21st April 2012, 01:39 AM   #25
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I may do the swing later on - I was looking at some things at lowes/homedepot to come up with something as such. I've almost put together some magnet mounts instead - may have some pictures tonight of that.

Thanks for the links!
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Old 21st April 2012, 12:51 PM   #26
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And of course obligatory pictars!

Click the image to open in full size.

Click the image to open in full size.
Good to see you've got the speakers:TV size ratio about right.
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Old 21st April 2012, 02:55 PM   #27
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Default 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
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Old 21st April 2012, 05:23 PM   #28
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Originally Posted by chris661 View Post
Good to see you've got the speakers:TV size ratio about right.


Quote:
Originally Posted by John Bsuch View Post
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.
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Old 21st April 2012, 11:42 PM   #29
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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. :/
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Old 28th April 2012, 02:53 PM   #30
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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?
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