Hi, I hate to ask this, because I'm sure others have before me.. But I don't have a ton of time for research right now.. (Just bought a new house that I'm rehabbing, and I need speakers for it).
I have a pair of Emminence 15" woofers. I want to build an OB speaker system for them. I will be bi-amping w/ active xover. My amps are both only about 5 watts.
The active xover gives me a lot of flexibility.
I was going to go for alpair 7 or 10's, but just looked at their efficiency, and they aren't great there. And, then I started going down the rabbit hole of looking at everything available and second guessing every thought I have... Then I notice over 2 hours have passed and I should be ripping out old kitchen cabinets.
So, maybe I'll see if anyone here is kind enough to answer my question so I don't need to spend hours researching 🙂.
I've always used fotex full range drivers in the past.. (I've built a few horn speakrs and one FAST style pair). So, I do like fostex, but would try anything. I would like to spend under $200 per driver.
That might be all the info you need.
Thanks for any advice.
I have a pair of Emminence 15" woofers. I want to build an OB speaker system for them. I will be bi-amping w/ active xover. My amps are both only about 5 watts.
The active xover gives me a lot of flexibility.
I was going to go for alpair 7 or 10's, but just looked at their efficiency, and they aren't great there. And, then I started going down the rabbit hole of looking at everything available and second guessing every thought I have... Then I notice over 2 hours have passed and I should be ripping out old kitchen cabinets.
So, maybe I'll see if anyone here is kind enough to answer my question so I don't need to spend hours researching 🙂.
I've always used fotex full range drivers in the past.. (I've built a few horn speakrs and one FAST style pair). So, I do like fostex, but would try anything. I would like to spend under $200 per driver.
That might be all the info you need.
Thanks for any advice.
Have you heard an OB system in a room similar to where these would be operating?
Presumably you've read one of the better series of treatises on the subject - OB Theory
While a good active XO can certainly provide all the flexibility of turnover points, slopes and perhaps even EQ, I wonder if the 5WPC would be more of a limiting factor on the woofers than whatever FR drivers you elect for the top end.
That said, if you've been happy with sound of Fostex in the past, there's no reason to avoid them for this project, but of other affordable full rangers to consider would be Alpair (A7.3, A10P) Dayton (PS180 / 220), TangBand - and numerous others to be listed shortly, no doubt.
Presumably you've read one of the better series of treatises on the subject - OB Theory
While a good active XO can certainly provide all the flexibility of turnover points, slopes and perhaps even EQ, I wonder if the 5WPC would be more of a limiting factor on the woofers than whatever FR drivers you elect for the top end.
That said, if you've been happy with sound of Fostex in the past, there's no reason to avoid them for this project, but of other affordable full rangers to consider would be Alpair (A7.3, A10P) Dayton (PS180 / 220), TangBand - and numerous others to be listed shortly, no doubt.
Oh, you made me double check something.. which is that the woofers are rated at over 95db/w, but, looking at the graphs, that's not at the frequencies I'm using them for. They're much lower in the 20-100hz range. So, w/ that in mind, maybe the alpair's are a better match than I initially thought.
And yeah, all of my existing low power systems have active subs... I just got this miniDSP, and was hoping to play with bi-amping, but all of my amps are low powered. I guess one of them I'm planning to use is really more like 7-10 watts per channel.. the other is definitely around 5.
And yeah, all of my existing low power systems have active subs... I just got this miniDSP, and was hoping to play with bi-amping, but all of my amps are low powered. I guess one of them I'm planning to use is really more like 7-10 watts per channel.. the other is definitely around 5.
I'm thinking Hoffman's Iron Law might have a special corollary when the bass driver has no enclosure at all?
To make sense out of the published sensitivity specs, it's helpful to know what the measurement conditions were. If assuming "standard" IEC baffles in anechoic chamber, for a 15" woofer that is 2530x3000mm. You can of course go much smaller than that, but with the requirement for substantially more power - assuming the voice coil can handle it.
To make sense out of the published sensitivity specs, it's helpful to know what the measurement conditions were. If assuming "standard" IEC baffles in anechoic chamber, for a 15" woofer that is 2530x3000mm. You can of course go much smaller than that, but with the requirement for substantially more power - assuming the voice coil can handle it.
The alpha 15a's.
I've also got a pair of these 12" MCM's sitting in storage..
http://www.farnell.com/datasheets/2...41.1723477139.1526315211-460967690.1526315211
(And thanks guys, for your replies!)
I've also got a pair of these 12" MCM's sitting in storage..
http://www.farnell.com/datasheets/2...41.1723477139.1526315211-460967690.1526315211
(And thanks guys, for your replies!)
Your link takes me to the main page.
The Alphas are well suited to the OB game, and you're right, the sensitivity of them is lower when using them OB so the Alpairs are a good match.
The Alphas are well suited to the OB game, and you're right, the sensitivity of them is lower when using them OB so the Alpairs are a good match.
Maybe this one w/out the crud after the URL?
http://www.farnell.com/datasheets/2329552.pdf
If not, they're the mcm 55-2982 part number..
(I don't expect anyone to actually go and google things for me, but thanks for the help!)
http://www.farnell.com/datasheets/2329552.pdf
If not, they're the mcm 55-2982 part number..
(I don't expect anyone to actually go and google things for me, but thanks for the help!)
from my brief exposure to MCM metal cone drivers a few year ago, I'd take anything by Fostex or Mark Audio with suitable sensitivity for your task
FWIW, I'm linking (below) to a recent post I made on this site regarding OB/dipole design, since you are in the design stages now.
Basically I assert that mounting a full ranger centrally on a big planar OB is bad (or at least has some big flaws), and suggest a way to design an OB that should sound "better". My 2 cents for you, and others who will listen.
http://www.diyaudio.com/forums/multi-way/320815-multi-ob-2.html#post5389471
Basically I assert that mounting a full ranger centrally on a big planar OB is bad (or at least has some big flaws), and suggest a way to design an OB that should sound "better". My 2 cents for you, and others who will listen.
http://www.diyaudio.com/forums/multi-way/320815-multi-ob-2.html#post5389471
Martin’s work on his passive OB used the Alpha 15. Once all is said and done a FR of 86-87 dB was a good match sensitivity wise. We used FF85k… current FF85wk or Alpair 5.2 or 6.2 would be a good choice for midTweeter.
dave
dave
While not a fan of OBs for my own reasons, everyone needs to try something new at least once. My only concern is that 5 wpc could make for limited SPL / dynamics. etc.
Open baffle has bass loss that you have to deal with. That means you will not get anything like the woofer's rated SPL in the low end, unless you use a giant baffle.
Since the woofer is losing level as the frequency descends, you'll have to attenuate the top end to match it, or end up with a very poor tonal balance. The overall efficiency is limited by the low end. You can lose as much as 10-12dB, but the Alpha won't be that bad. All that adds up to your fullrange/tweeter not needling to be as efficient as the woofer. Of course it could be more efficient and you'd use attenuation.
The main thing to learn with OB is how to flatten the woofer response, and do it with the crossover.
Since the woofer is losing level as the frequency descends, you'll have to attenuate the top end to match it, or end up with a very poor tonal balance. The overall efficiency is limited by the low end. You can lose as much as 10-12dB, but the Alpha won't be that bad. All that adds up to your fullrange/tweeter not needling to be as efficient as the woofer. Of course it could be more efficient and you'd use attenuation.
The main thing to learn with OB is how to flatten the woofer response, and do it with the crossover.
..and correction (dsp eq. with the minidsp) requires power.
5 watts for the woofer really isn't going to cut it.
5 watts for the woofer really isn't going to cut it.
No it's not. But the Alpha 15 is a high Qts woofer, so the bass doesn't suffer as much as a more typical woofer. That's one of the reasons for its popularity on OB.
So, taking your good advice about my lack of power for bass..
Are there any good speaker options for low powered bi-amping/active xover?
Would boxed speakers be a better idea? So a woofer box, and a full range maybe open or also in an enclosure. Then I'm basically to where I am w/ all my speaker systems.. Which is a full range horn or other boxed enclosure, with subwoofers to pick up the low end. But if that's the best option, I'll stick w/ it.
Are there any good speaker options for low powered bi-amping/active xover?
Would boxed speakers be a better idea? So a woofer box, and a full range maybe open or also in an enclosure. Then I'm basically to where I am w/ all my speaker systems.. Which is a full range horn or other boxed enclosure, with subwoofers to pick up the low end. But if that's the best option, I'll stick w/ it.
It's not "best", it's just different. You should certainly try OB and learn how to work out the crossover. You may like the open sound and lack of boxiness that OB brings, a lot of people do. Plus, so much less woodwork. 😉 The way they interact with the room is different, and placement is important. Since you already have the Alpha woofers, why not give it a try?
How big can your baffle be?
How big can your baffle be?
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