New speaker build

[Poultrygeist]

http://gallery.audioreview.com/data/audio/500/medium/PA280008.JPG

[Poultrygeist]

This is one of two Open Baffle 15 inch Alpha bass helpers/augmentors I built over the weekend. The crossover is a 80hz unit from Parts Express. I drive these with a JVC class d av receiver which receives it's signal from a CDP's optical output. The analog output signal from the same CDP is fed to a Dared 2a3c integrated tube amp which drives two Tekton 4.5s. I use this secondary bookshelf set up in a home office.

[Poultrygeist]

http://gallery.audioreview.com/data/audio/500/medium/PA280009.JPG

[Ajani]

How close does the performance of this simpler design come to the H-Frames?

[Poultrygeist]

Very close and it takes up a lot less space.

[Ajani]

Cool... I'm nowhere near ready to embark on a DIY project... but OB builds keep catching my interest as they seem like something even I could do + they will sound different from the kind of speakers I normally buy (so even if I don't love them I'm at least guaranteed sonic variety)...

I'm thinking a straightforward OB build with 15" alphas and 8" fullrange will be a sweet 1st DIY project (maybe sometime next year)...

[Poultrygeist]

http://gallery.audioreview.com/data/audio/500/medium/PA280004.JPG

[Ajani]

Nice pic... That certainly looks discrete

[Poultrygeist]

There's a built-in bookcase exactly like this one on the other side of the room and I have a second bass augmentor and Tekton in the same location as these. I don't care much for a bookcase set up but the wife wants no more speakers on the office floor.

You could get by with just one of these bass augmentors. The Alpha driver is like $65 and the low pass crossover was under $20. I really love these puppies as they give a great bass foundation to everything I try them with. When I mute them I scratch my head in amazement that I could have ever lived without them.

Ajani, you really should try a simple OB build. Hearing is believing.

[Poultrygeist]

http://gallery.audioreview.com/data/audio/500/medium/PA280014.JPG

[cackalacky]

This is one of two Open Baffle 15 inch Alpha bass helpers/augmentors I built over the weekend. The crossover is a 80hz unit from Parts Express. I drive these with a JVC class d av receiver which receives it's signal from a CDP's optical output. The analog output signal from the same CDP is fed to a Dared 2a3c integrated tube amp which drives two Tekton 4.5s. I use this secondary bookshelf set up in a home office.

Any recommendations for "how-to get started" DIY books/manuals? I have decent woodworking/carpentry skills, but know little-to-nothing about electronics.

[Poultrygeist]

cackalacky,

You should start with full range ( aka wide band ) speakers. Not only do they produce great sound but they are very simple in terms of electronics. The reason is they usually have only one driver per enclosure or baffle with no crossover. In most cases you can wire the drivers straight to the amplifier. For convenience sake I generally wire from the driver to terminals that accept banana plugs. You can use regular speaker wire with the internals but I like 14 gauge hook up wire from Lowes. I make all connections with crimp on female connectors so soldering is not necessary.

Open baffle full range speakers are really easy to build as you can see from some of the ones I've posted in the speaker forum. Full range box speakers are more challenging. If you can tell me your driver budget and the size you want I can make some suggestions. There are dozens of free plans on line. Everything I've built, someone else built first and gave it high marks. Unfortunately there is little DIY stuff on this forum but DIY Audio and AC are great project resources.

If you have decent woodworking skills you are far ahead of me. I struggle with precise cuts on plywood. If you have a router you should purchase a Jasper Circle Guide to cut driver holes. There are many other good guides but the Jasper is a popular choice. I started out using a jig saw and while it works ok the results for holes is not so pretty. Good quality 3/4 plywood is the material of choice but MDF is fine if you can deal with the toxic dust. Baltic birch is top shelf but being a thrifty Scot I usually go with the cheaper stuff.

About 10 years ago I sold a very collectable Sansui tuner to a guy in Florida. I got to know him through correspondence and learned that he had sold all his high end speakers as he had learned to build better stuff. I didn't really believe him but as the years passed I began to read the DIY forums. About three years ago I built a pair of folding wing OB Betsy's and then I knew there was something very special in DIY speakers. My DIY $100 Betsy's were far more musical and enjoyable than my $2000 Aerial Acoustics which I soon sold. Last week I received an email from a guy who read my posts about the OB Betsy's. He said he was so encouraged by my comments that he built a pair. He liked them so much he sold his expensive Omega's.

I've listened to all the great stuff from huge Maggies to $30K Meridians but none of it gets me closer to the music than my simple OB speakers.

The difference between DIY and commercial is that you can afford to spend $200 on a set of drivers but they can't and still make a profit. There are few companies making open baffle speakers and the reason is there's so little profit margin in such simple designs. 75% of the cost of commercial audio gear goes for cosmetics while most of us would prefer it go for sound. With DIY you can control where that 75% goes.

[cackalacky]

Thanks for the info and advice. I'll start doing some reading/research, maybe build myself something for Christmas.

[StevenSurprenant]

I've only built one pair of DIY speakers using the Newform 45 inch tweeter and SEAS woofers. The result was phenomenal and I find that I have lost all interest in going to audio stores, which used to be one of my favorite things to do.

I was lucky and got my parts on the cheap.

Your OB woofer looks nice. especially for it's simplicity and low cost. Makes me think about doing the same.

Your advice to cackalacky is right on the money. I might add that if you want to experiment with multi driver speakers, the Behringer DCX2496 makes a nice platform for that. It allows you to set crossover points and slopes, amongst other things, during crossover design.

Of course, as you said, there are many DIY plans available which would be a good starting point and take all the guess work out of it.

[Ajani]

I might add that if you want to experiment with multi driver speakers, the Behringer DCX2496 makes a nice platform for that. It allows you to set crossover points and slopes, amongst other things, during crossover design.


That's the exact unit I've been looking at with some interest... As I've seen it used in more expensive products from Emerald Physics, such as the CS2.7 ($7,995):

CS2.7 (http://www.emeraldphysics.com/page21/page21.html)

I like the idea of having that level of flexibility re crossover and equalization...

If I do eventually pull the trigger on an OB project, I'd be seriously looking at this combination:

Behringer DCX2496 Ultradrive Pro Digital Crossover ($326.99)
Behringer DCX2496 Ultradrive Pro Digital Crossover 248-669 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-669)

+

Dayton Audio PS220-8 8" Point Source Full-Range Neo Driver ($218.98 per pair)
Dayton Audio PS220-8 8" Point Source Full-Range Neo Driver 295-346 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-346)

+

Dayton Audio PA380-8 15" Pro Woofer ($179.20 per pair)
Dayton Audio PA380-8 15" Pro Woofer 295-034 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-034&FTR=)

=

TOTAL $725.17

[Ajani]

I'd opt to build something looking like this:

http://diyaudioprojects.com/Gallery/albums/userpics/Goldwood-Open-Baffle-Speakers.jpg

[Poultrygeist]

Ajani,

A regular woofer is not recommended for OB. It should be full range with a high Qt. rating ( >1 ). The Dayton APA 150 amp linked below will drive two Alpha 15As and no external crossover device is needed as the Dayton ( aka Emotiva BPA-1 ) has it's on active crossover control. The Dayton is on sale now for a great price. You can check out the BPA-1 manual at the Emo site.

If you still have your Emotiva Preamp Dac you could put it to good use by converting the optical out signal from a CDP to analog and sending it to the Dayton while sending your analog CDP output to a separate amp to drive the 8 inch full rangers. This is true bi-amping at it's best and it will sound much better than the OBs in your picture above which employ passive crossovers. Don't get me started on the evils of passive XO's. Solid state is best for bass drivers while tubes are preferred for the upper frequency FR drivers.

SS, I've got a complicated Behringer electonic crossover ( they're all complicated to me ) and the 3 page manual is a joke. I need to take a course in how to set it up.

If you guys ever go OB you won't come back - I promise!

Dayton Audio APA150 150W Power Amplifier 300-812 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-812)

[Poultrygeist]

Inspiration for my H-frame Open Baffles

http://www.quarter-wave.com/Project08/Passive_Crossover.pdf

[Poultrygeist]

Here is the Eminence Alpha 15A full range bass driver as used in this build.

Eminence Alpha-15A 15" Driver 290-407 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-407&FTR=alpha%2015)

[StevenSurprenant]

That's the exact unit I've been looking at with some interest...

Behringer DCX2496 Ultradrive Pro Digital Crossover ($326.99)
Behringer DCX2496 Ultradrive Pro Digital Crossover 248-669 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-669)

Here is the link to Behringers site. BEHRINGER: News (http://www.behringer.com/EN/news/popup)


SS, I've got a complicated Behringer electonic crossover ( they're all complicated to me ) and the 3 page manual is a joke. I need to take a course in how to set it up.


It's not complicated once you understand how to get to the functions. You can use the software supplied by Behringer and your computer to make it really simple. It reduces the learning curve tremendously. Here's the link to the software. It's hard to find on their web site so if you're inclined to get one, I'd copy this link or download the software now.

http://behringerdownload.de/_software/DCX2496_remote_1_16a.zip

Things to know...

It uses a RS232 connection to the computer and new computers don't use this any more. There are RS232 to USB adapters that should allow you to make the conversion. You will also need a RS232 cable. Get a long one unless your audio electronics is sitting right next to your computer... Dayton Audio XFRF XLR Female to RCA Female Adapter 240-428 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=240-428)

INPUT "A" will take either digital or analog. Do not use Analog inputs because the signal will degrade when using lower analog volumes. Just connect a coax cable from your CD/DVD player to INPUT A.

Set your CD/DVD player to PCM output. If you feed the DCX the RAW output, it may have trouble deciphering it if it's multi channel.

Unless you are running balanced connections (XLR) you will need adapters for the input and the outputs. (XLR to RCA)

For output (analog) - order one cable for each channel : The DCX can output 6 channels for 2-3 way speakers if you choose that. You only need 4 cables for 2-2 way speakers.

(Female XLR to male RCA) HDMI Cable, Home Theater Accessories, HDMI Products, Cables, Adapters, Video/Audio Switch, Networking, USB, Firewire, Printer Toner, and more! (http://www.monoprice.com/products/search.asp?keyword=female+xlr+to+rca+&x=0&y=0)

You can also use these if you want to use your own cables: Dayton Audio XFRF XLR Female to RCA Female Adapter 240-428 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=240-428)

For input (digital) - order one adapter and then use a 75 ohm digital cable between the DCX and your player. If your player has a balanced digital output then you don't need this, only a 110 ohm cable. If you decide to input analog, you will need two adapters.

(Male XLR to Female RCA) : Dayton Audio XMRF XLR Male to RCA Female Adapter 240-438 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=240-438)

The last thing you will need is a multi channel preamp into separate amps or just a receiver that allows discrete inputs to 4 or more channels. You can just use amps with built on volume controls, but it makes it a little harder to use. It just means that you have to adjust the left or right channel independently, that's all.

I hope this helps.

Once you understand the functions and how to get to them, this will seem as simple as adjusting your TV.

[Poultrygeist]

Thanks SS, that some great information to digest. I have the XLR adaptors to get started but I need to gear myself up mentally to start my learning curve which begins at zero. I've been so smitten with building OB variations my brain is preoccupied.

Ajani,

Here's Steve's ( at Decware ) take on some FR drivers for Open Baffle. He prefers my Tang Band W8-1808s to the Seas Exotic X1 ( at $830 each ).

DECWARE - Audio Paper Zen Open Baffle Speaker (http://www.decware.com/newsite/paper95B.html)

[Ajani]

Looks like the Dayton drivers only have good build (I'll miss the terminals)... So it means I'll stick with the tried and true options:

Either

Fostex FE206En 8" Full Range ($204.80 per pair)
Fostex FE206En 8" Full Range: Madisound Speaker Store (http://www.madisoundspeakerstore.com/approx-8-fullrange/fostex-fe206en-8-full-range/)

OR

Tang Band W8-1808 8" ($500 per pair) - Pricey for a first project...
Tang Band W8-1808 8" Neodymium Full Range Driver 264-894 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-894)

+

Eminence Alpha-15A ($130 per pair)
Eminence Alpha-15A 15" Driver 290-407 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-407)

I'd still opt for Behringer for flexibility... especially since I still have an Emotiva XPA-2 lying around, that would be ideal for running bass drivers...

[Poultrygeist]

For cheap and cheerful this FR driver below is hard to beat. I replaced some decayed drivers in a Realistic Nova cabinet with them and was shocked at how good they sound. They were cheaper than the re-foam kit. No doubt they'd sound good in OB.

GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW 292-430 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-430&FTR=grs%20full%20range)

[Ajani]

For cheap and cheerful this FR driver below is hard to beat. I replaced some decayed drivers in a Realistic Nova cabinet with them and was shocked at how good they sound. They were cheaper than the re-foam kit. No doubt they'd sound good in OB.

GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW 292-430 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-430&FTR=grs%20full%20range)


That's a bit too cheap and cheerful for me... When I do proceed I'll want something good enough for me to really hear the sonic benefits of OB, but not so expensive that I'd be annoyed if the sound isn't totally to my liking...

What are your thoughts on the Tang Bands VS the Fostex?

[Poultrygeist]

A neat thing about OB and FR SD is that you can often swap drivers with just a screw driver. Lots of 8 inch drivers fit the same hole. Many DIYers just make a simple universal "supra baffle" which they swap in and out when they want to try something different. Imagine doing that with commercially built monkey coffins with complex crossed over multi-drivers. While many folks spend countless anally retentive hours in an attempt to hear some micro difference in cables I can drop in a new driver and bingo it's like night and day. A hobby to me is one that's flexible and dynamic enough to afford change without going bankrupt. If I had to live with one system and never change or modify it, I'd be looking for a new hobby. I know there must be lots of frustrated audiophiles who are only held back by a fear of following their imagination.

Price is even less a predictor of quality in DIY than in commercial offerings as some of the cheapest solutions are often the best i.e. the fabulous 1980's $10 full range driver from Rat Shack that has a cult following. It appears the GRS 8 which replaces the ubber cheap but legendary Pioneer BOFU ( checkout Nelson Pass's BIB version ) will become another cult classic. BIB is short for "big is better" in DIY lingo.

The TB W8-1808 is so buttery smooth with a larger sound stage than the little FE126E. I can listen to them all day and still listen some more. They lack some of the micro detail of the Fostex 4.5 but they're so pleasant you wouldn't know you were missing anything and maybe you aren't. The TB's are more refined than the clinically accurate Fostex. I like a super tweet with the larger TB whereas the Fostex doesn't need one. They both need bass augmentation although the TB in a large monkey coffin wouldn't. I have never heard the larger Fostexs but the 4.5 seems to be the most popular. I have the FE126En in my four Frugal Horn and center surround system and the FE126E models in my Tektons 2 channel bass augmented system. The FE126 is best in horns but do fine in Tekton's bass reflex but for OB the TB is the better choice.

Since I've added these OB bass augmenters to the Tektons I've been giving them equal play time as the TB/H-frames. I'm crazy about both and prefer them to the Zu's or any commercial speaker I've heard.

[Poultrygeist]

This is what got me started in OB and I've read it several times.

Gravity Well Of A DarkStar (http://www.audiocircle.com/index.php?topic=19253.0)

And after 1,403 posts and 6 1/2 years this thread is still alive.

[Ajani]

A neat thing about OB and FR SD is that you can often swap drivers with just a screw driver. Lots of 8 inch drivers fit the same hole. Many DIYers just make a simple universal "supra baffle" which they swap in and out when they want to try something different. Imagine doing that with commercially built monkey coffins with complex crossed over multi-drivers. While many folks spend countless anally retentive hours in an attempt to hear some micro difference in cables I can drop in a new driver and bingo it's like night and day. A hobby to me is one that's flexible and dynamic enough to afford change without going bankrupt. If I had to live with one system and never change or modify it, I'd be looking for a new hobby. I know there must be lots of frustrated audiophiles who are only held back by a fear of following their imagination.

IMO, that is the strongest point in favour of most of these OB designs... If you enjoying changing the sound, it can be done quite easily...

A simple OB design with a cutout for a 15" woofer and 8" FR gives you numerous options for switching out drivers... I think the addition of an active crossover (even if the learning curve is steep) makes it all the more flexible...

[Ajani]

This is what got me started in OB and I've read it several times.

Gravity Well Of A DarkStar (http://www.audiocircle.com/index.php?topic=19253.0)

And after 1,403 posts and 6 1/2 years this thread is still alive.

Thanks for the link...

I'm sure it will be useful when I eventually put on my "mad scientist coat" and start building...

[dundo]

I will have a pair of Visaton NoBox BB in home in few days. If anybody is interested in impresions please leave a note here. Old but proven OB design.