Open baffle fullrange project help?

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Hello everyone. I hope all is well. So I'm thinking of my next project for a my dad's cottage up north. The other speakers I built him well little hands got involved and that was that. So now am looking to build a speaker with different drivers and a more diepole sound for my dad's earing. If that makes sense. So what do I need to look for in a drivers spec's? I am looking for a fullrange driver for this project. So can someone please help me or point me in the right direction? Thanks Jeff

P.s. I have read that BL and a higher Qts is the most important? If that's true?
 
The suspension of the drivers designed to work without the air cushion of a box in an open baffle are specifically built for that purpose - the suspension is different (hence the higher Qts) and the magnetic field is also different (that BL)

There's a wide range of devices built for just this use but it's quite hard to determine one specific model for your use and it does depend a bit on the type of amplifier - for your father, he might appreciate tone controls of an integrated amplifier, altho these are a bit 'out-of-favour' these days but some excellent units are available at reasonable prices, or second hand

Some details of the room size, types of music (ie how much bass, etc) and an idea of budget would help a bit - my dad, a bit deaf now, loves old big band sound 'up loud' and it required a lot of soundproofing for the listening room - not particularly expensive but getting it to look like a 'normal room' did require some extra work.

I'm playing with OB (open baffle) these days but using the WAW system (Wide range driver & Woofer? - the old FAST idea) with the 15" bass driver, an 8" Full Range driver and an electronic crossover - I have found the relatively inexpensive Wild Burro "Betsy" drivers are rather good value so this might give you some idea to start with

I see you're in Michigan so you do have ready access to a wide variety of drivers and experienced diy people too - all the best
 
The suspension of the drivers designed to work without the air cushion of a box in an open baffle are specifically built for that purpose - the suspension is different (hence the higher Qts) and the magnetic field is also different (that BL)

There's a wide range of devices built for just this use but it's quite hard to determine one specific model for your use and it does depend a bit on the type of amplifier - for your father, he might appreciate tone controls of an integrated amplifier, altho these are a bit 'out-of-favour' these days but some excellent units are available at reasonable prices, or second hand

Some details of the room size, types of music (ie how much bass, etc) and an idea of budget would help a bit - my dad, a bit deaf now, loves old big band sound 'up loud' and it required a lot of soundproofing for the listening room - not particularly expensive but getting it to look like a 'normal room' did require some extra work.

I'm playing with OB (open baffle) these days but using the WAW system (Wide range driver & Woofer? - the old FAST idea) with the 15" bass driver, an 8" Full Range driver and an electronic crossover - I have found the relatively inexpensive Wild Burro "Betsy" drivers are rather good value so this might give you some idea to start with

I see you're in Michigan so you do have ready access to a wide variety of drivers and experienced diy people too - all the best



Hello there. Well my dad has a very nice older Kenwood 2 channel integrated amp with tone controls. It's heavy and is a beast and can drive anything from 6 ohms to 8 ohms I think? My dad's hearing is not the best. The room size is a open basement and a little bedroom off to the left of you and next to it is the storage room / furnace and water tank room. Lots of wood trim around the room and a door wall and windows of course. I have no idea how big it is? Next Time I go up I can measure it. Yes I live in Michigan and yes I have a few places I can get drivers from.
Madisound and Parts Express and meniscus audio group and solen in Canada. So I have a lot to choose from. I do like the fast design with a smaller driver and a bigger woofer. Paper drivers are my Preferred Choice. But little hands can push in the dust caps or poke holes in them. Also with fabric dome seas tweeters very nice tweeters but, no grills so they got pushed in pretty deep. I am looking for drivers with phase plugs or hard plastic dust caps. I do have 4 ohm Dayton Audio fullrange drivers but again the Kenwood doesn't go down to 4 ohms. I was thinking of a open baffle with grill cloths covering the driver holes from the inside and having the drivers mounted from the inside so that would help not draw attention to poking the drivers. I have Supra speaker cables and I am making him new stereo rca cables for his stereo system . Well he listens to records and live TV for now. So my thought was using the Dayton audio stuff because it's not to bad in price and I will not loose my butt on it if they get damaged like the other speaker's I build my dad years ago. Jeff
 
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frugal-phile™
Joined 2001
Paid Member
Choice of full range drivers that can produce bass on an OB is limited. Hence the popularity of WAW (formerly FAST) systems. Get a big bass driver to cover the lowest frequencies and the FR is crossed high enuff that not being able to produce bass is moot. One gets all the benefits of a WAW but pays the price of 4 drivers instead of 2, and either a passive XO (greatly complicating things). Parts can be pricey enuff to make bi-amping cheaper, but now 4 amp channels and an active XO.

The only 2 drivers i could recommend for a FR OB are the Betsy and the more expensive Visaton B200 (but better IMO, phase plugs required). There are some special drivers, like the SAL and i have an unobtainium Korean AlNiCo 6.5” dedicated to OB.

dave
 
Choice of full range rivers that can produce bass on an OB is limited. Hence the popularity of WAW (formerly FAST) systems. Get a big bass driver to cover the lowest frequencies and the FR is crossed high enuff that not being able to produce bass is moot. One gets all the benefits of a WAW but pays the price of 4 drivers instead of 2, and either a passive XO (greatly complicating things). Parts can be pricey enuff to make bi-amping cheaper, but now 4 amp channels and an active XO.

The only 2 drivers i could recommend for a FR OB are the Betsy and the more expensive Visaton B200 (but better IMO, phase plugs required). There are some special drivers, like the SAL and i have an unobtainium Korean AlNiCo 6.5” dedicated to OB.

dave



Well that stinks. I thought there would be more choices in fullrange O.B. design. Well hummm. If I wanted to use just a fullrange driver would the sea's H 1597-08 drivers be good for listening to records? Or movies? I like the look of them and that they can be used in a sealed box per. Sea's. I guess I thought there again was more drivers on the market for O.B. designs? Sea's also has a 4 1/2 inch poly curved fullrange cone drivers as well that I see and like. I also found a 5 inch poly cone from Tang Band looks nice but, how does it sound? I am learning that a driver can look really awesome and sound bad got burned a few times. So now I will have to narrow down the drivers I find and hoping someone will help me? Jeff
 
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Dayton and/or Madisound have a whole range of clipon or screwed mesh cover speaker covers for the front and a simple woven mesh grill at the back to ptotect the driver from 'itchie fingers' and curious cats

Dave, do you have a photo of the revised phase plug for the Betsy, by any chance? And what woud your second recommended driver be?
 
Founder of XSA-Labs
Joined 2012
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How about the manzanita? I built a pair with my dad recently and he’s very happy with them - they sound great :)

Oh and they’re cheap!

I would recommend these too if you want a nice well-designed OB using a full range driver. I wouldn't call them cheap though as parts are around $400 the last time I checked. They also need a pretty muscular amp.

If you get a miniDSP, your choices are almost limitless for an OB.

An interesting choice for a full range top is a PRV 5MR540NDY - it goes down to about 300Hz. It is about 95dB sensitive so up there with Lowther territory. You will need at least a pair of 15in woofers to get enough bass on the bottom to balance the top.

PRV 5MR450-NDY for FAST applications

428956d1405605701-prv-5mr450-ndy-fast-applications-5mr450ndy-fast-furious-ob-response.png


Maybe take a look at a K-aperture Z baffle or KaZba dipole:
Rockin' the KaZba Dipole (K aperture Z-baffle Dipole)

driver_alignmnet_zpsucjcfrip.png~original


CLS made a very nice one with two 15in drivers - I believe it is his current system.

DSCF8063_zpsolpwsrkx.jpg~original


Here was one of my experiments with a 3 way OB with a KaZba woofer and a TG9FD mid and a dome tweeter. You can make a XO like this with some clicks of a mouse and a microphone when you have miniDSP:
509646d1445209589-ob-compact-3way-nearfield-monitor-image.jpg


This was measured from this speaker:
509645d1445209092-ob-compact-3way-nearfield-monitor-image.jpg
 
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I don't know if the room is appropriate for a O.B. speaker. I wanted to start some where and thought of building a pair for my dad for Christmas? I am new to O.B. design and this will be my real first system if it works out? I could always leave the fullrange driver open in the back and have the bigger woofer sealed? Still thinking about the cost and time and design of the project? Jeff
 
Choice of full range drivers that can produce bass on an OB is limited. Hence the popularity of WAW (formerly FAST) systems. Get a big bass driver to cover the lowest frequencies and the FR is crossed high enuff that not being able to produce bass is moot. One gets all the benefits of a WAW but pays the price of 4 drivers instead of 2, and either a passive XO (greatly complicating things). Parts can be pricey enuff to make bi-amping cheaper, but now 4 amp channels and an active XO.

The only 2 drivers i could recommend for a FR OB are the Betsy and the more expensive Visaton B200 (but better IMO, phase plugs required). There are some special drivers, like the SAL and i have an unobtainium Korean AlNiCo 6.5” dedicated to OB.

dave



So Dave ( sorry for the late reply ) but, I forgot to mention a 8 inch fullrange driver? The Tang Band W8-1808 driver. It has a higher Qts and is made for a open baffle and a larger encloser. Have you used or tried this driver sound or conpaired to other fullrange drivers? What's thoughts on this driver being made for an open baffle? Thanks Jeff
 
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