The fs is near perfect for use in an H frame, because the fs in the frame will drop into the low 30's and you just are not going to get much useful output below 30hz on any open system.
freddi,
I would keep the depth the same as the other H frame designs, I think it is 16" external depth. For the width and height, I would use 1" to 2" bigger then the driver frame OD. Crossover to a midbass or full range driver between 100 and 200 Hz using a 2nd order filter. It is a very simple design.
I would keep the depth the same as the other H frame designs, I think it is 16" external depth. For the width and height, I would use 1" to 2" bigger then the driver frame OD. Crossover to a midbass or full range driver between 100 and 200 Hz using a 2nd order filter. It is a very simple design.
thanks Martin - my friend clamped the H-baffles together and briefly tried Omega Pro 18 and Delta 15 (latter was best out of what he had) with a car coax and was surprised with their bass clarity - said couldn't get them close to a back wall without losing bass extension - whats ~ minimum distance for most H-baffle woofers to rear wall to "breathe"? are some of the cheaper digital crossovers good sound-wise?
Freddy
Freddy
freddi,
My H frames have a calculated and outdoor measured lower frequency limit (-3 dB) of just over 20 Hz. When I put them in a room they are about 3 to 4 ft from the rear wall and pointed towards a corner and I measure response down to about 30 Hz.
You really need to be a few feet from the walls and use a driver with a Qts of about 1.0. I think the drivers you mention have lower Qts values which will roll off the bass. I cannot emphasize enough the advantage of higher Qts woofers in OB speaker systems.
The only digital crossover I have used is the dBx Driverack PA, it is not that expensive and has worked well for me. Right now I am using a passive crossover for the H frame and OB system which sounds very good.
My H frames have a calculated and outdoor measured lower frequency limit (-3 dB) of just over 20 Hz. When I put them in a room they are about 3 to 4 ft from the rear wall and pointed towards a corner and I measure response down to about 30 Hz.
You really need to be a few feet from the walls and use a driver with a Qts of about 1.0. I think the drivers you mention have lower Qts values which will roll off the bass. I cannot emphasize enough the advantage of higher Qts woofers in OB speaker systems.
The only digital crossover I have used is the dBx Driverack PA, it is not that expensive and has worked well for me. Right now I am using a passive crossover for the H frame and OB system which sounds very good.
BIB / H frame integration
"With the H-Frames bass on the Wicked cd is full and bouncy. Without them bass is light. There is a generous ease of presentation with large woofers. I'm spoiled for anything else!"
Godzilla,
Any issue with integration of bass generated by your BIB with H frame woofer? Do they overlap?
How would you go if starting from scratch?
A. BIB w/ full range driver augmented by H frame mounted 15" woofer.
B. full range driver in OB on top of the H frame ( like MJK's project).
Hoping to get started soon. I have homebrew 300b set monoblocks to drive the full rangers and would use plate amps to drive the woofers. FR are 8" Audio Nirvana Super Cast Frame drivers.
Many thanks,
Mark
"With the H-Frames bass on the Wicked cd is full and bouncy. Without them bass is light. There is a generous ease of presentation with large woofers. I'm spoiled for anything else!"
Godzilla,
Any issue with integration of bass generated by your BIB with H frame woofer? Do they overlap?
How would you go if starting from scratch?
A. BIB w/ full range driver augmented by H frame mounted 15" woofer.
B. full range driver in OB on top of the H frame ( like MJK's project).
Hoping to get started soon. I have homebrew 300b set monoblocks to drive the full rangers and would use plate amps to drive the woofers. FR are 8" Audio Nirvana Super Cast Frame drivers.
Many thanks,
Mark
re: lower Q = were all my long distance friend had to try - - I've got Silver Iris, GW1858 and Madison X21 - all high Q - - - FWIW P-Audio's Sn15C with qts ~0.38 seemed to play ok on a small baffle and rough impression was not too bass shy - perhaps its midrange is down compared to some FR - - guess will have to get measuring stuff hooked up and look at what its doing. For $70 it was cool enough other than woofer cone being drenched with "the wet look" type coating front and back - looks alone implied "glare"....
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An externally hosted image should be here but it was not working when we last tested it.
I use this amp i bought from PE and it rocks... when it's working. It's already back for repair.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-812
Variable crossover from 50hz - 150hz. Once dialed in the setting was around 70hz with my BIBs. Bass was enormous, full and rich. I have them about 2-1/2 feet from the walls. They are easy to slide around because they are compact designs. They are only slightly larger than the woofers themselves. In a week or so i hope to have super tweeters sitting on top of them. Lately i like serving up my treble crispy.
Martin, is this the dbx you are using?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=246-170
>>> How would you go if starting from scratch?
Good question! I don't know! But i do like the BIBs stand alone without any bass augmentation at all... just that the H-frames offer more and better bass... the best i could have imagined. They rock the house! I am tempted to build an OB system. Have been considering the Eminence Lil Buddy plus a tweeter on OB for many months but really it's just something to think about as i move thru choosing speaker projects. One day i will get around to it. I think you have to consider your space and the look you want in your room. Your AN's can be used OB or in BIBs... The OB look will be cleaner while the BIB + H-frame will be bulkier. Since i built the BIBs first i had no choice. You have a choice. Sonically, either way should be excellent. Their is overlap between BIB and H-frame but the variable crossover and volume control allows pretty seamless integration.
Godzilla
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-812
Variable crossover from 50hz - 150hz. Once dialed in the setting was around 70hz with my BIBs. Bass was enormous, full and rich. I have them about 2-1/2 feet from the walls. They are easy to slide around because they are compact designs. They are only slightly larger than the woofers themselves. In a week or so i hope to have super tweeters sitting on top of them. Lately i like serving up my treble crispy.
Martin, is this the dbx you are using?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=246-170
>>> How would you go if starting from scratch?
Good question! I don't know! But i do like the BIBs stand alone without any bass augmentation at all... just that the H-frames offer more and better bass... the best i could have imagined. They rock the house! I am tempted to build an OB system. Have been considering the Eminence Lil Buddy plus a tweeter on OB for many months but really it's just something to think about as i move thru choosing speaker projects. One day i will get around to it. I think you have to consider your space and the look you want in your room. Your AN's can be used OB or in BIBs... The OB look will be cleaner while the BIB + H-frame will be bulkier. Since i built the BIBs first i had no choice. You have a choice. Sonically, either way should be excellent. Their is overlap between BIB and H-frame but the variable crossover and volume control allows pretty seamless integration.
Godzilla
"I think you have to consider your space and the look you want in your room." Godzilla
Thanks for the quick reply. Both approachs sound like fun but the OB with H frame woofer (verses BIB w/H) is probably a bit less expensive and better suited to my small listening room.
BTW, is the amp you reference above powering the woofers? Why this approach verses 2 plate amps?
Many thanks,
Mark
Thanks for the quick reply. Both approachs sound like fun but the OB with H frame woofer (verses BIB w/H) is probably a bit less expensive and better suited to my small listening room.
BTW, is the amp you reference above powering the woofers? Why this approach verses 2 plate amps?
Many thanks,
Mark
>>> BTW, is the amp you reference above powering the woofers? Why this approach verses 2 plate amps?
Cheepah and i don't have to build a box to put the plate amps into. I think a single plate amp would work too. Powered woofers are new to me so i may not be doing it the best way. Certainly the amp i chose offers the features i need. It's a chuncky piece too... if a little cheap. The volume knob is too sensitive. PE said they will fix it at no charge and others are also complaining about it. It's funny to see it next to my Cary tube amp. But solid state is the way to go for bass and that's another reason i chose it.
Enjoy building your project!
Godzilla
Cheepah and i don't have to build a box to put the plate amps into. I think a single plate amp would work too. Powered woofers are new to me so i may not be doing it the best way. Certainly the amp i chose offers the features i need. It's a chuncky piece too... if a little cheap. The volume knob is too sensitive. PE said they will fix it at no charge and others are also complaining about it. It's funny to see it next to my Cary tube amp. But solid state is the way to go for bass and that's another reason i chose it.
Enjoy building your project!
Godzilla
Yes that is the crossover, I bought it brand new on e-Bay for less than the PE price.
If you like the bass from the H frame and you are already crossing over between 100 and 200 Hz then you are perfectly positioned to put a smaller full range driver on an OB above it. I have both a Jordan JX92S and a Fostex F120A and they both work great, no need for a tweeter. My guess is that one of the Alpair units would also work well. Probably any one of the other small Fostex drivers would also work using an active crossover to match the potential mismatched in driver levels. A smaller OB is easy to build, cheap, and sitting on top of the H frame does not take up any more floor space. The combination sounds great, bass with authority and that clean open full range sound filling in the rest of the audio spectrum.
"Cheepah and i don't have to build a box to put the plate amps into. I think a single plate amp would work too. "
Are you running your woofers dual mono or stereo?
One woofer amp (in an enclosure) verses two is compelling, but I understand that it is a good idea to run them stereo.
Totally different question and probably off thread....how can a non-technical, non-math savy person determine the right baffle size to use with a full range driver (for mids and high only)?
I have seen some "rules" like width = 2.2 times the driver diameter. That would make the baffle 18" wide. I am guessing that height would be around 30" (it would sit on the H-frame).
Has anyone used the AN Super 8" Cast Frame in an OB (above 150-200 hz)?
Many thanks Godzilla and the rest of the DIY community!
Mark
Are you running your woofers dual mono or stereo?
One woofer amp (in an enclosure) verses two is compelling, but I understand that it is a good idea to run them stereo.
Totally different question and probably off thread....how can a non-technical, non-math savy person determine the right baffle size to use with a full range driver (for mids and high only)?
I have seen some "rules" like width = 2.2 times the driver diameter. That would make the baffle 18" wide. I am guessing that height would be around 30" (it would sit on the H-frame).
Has anyone used the AN Super 8" Cast Frame in an OB (above 150-200 hz)?
Many thanks Godzilla and the rest of the DIY community!
Mark
You should consider building a design that somebody has already worked out in detail and you believe will meet your performance/cost goals. Build exactly what they specify so you can achieve the same result. That will be the quickest path, with minimal risk, to a satisfying result.
Dayton APA150
Godzilla,
Are you using this Dayton APA150 as a stereo sub amp (meaning the amp can provide power for 2 of your H enclosures) instead of using 2 plate amps. I may just do the same as it is more convenience, cheaper and as you said, I dont have to build a box to put the plate amps into.
MJK, do you think I can use your H frame design and cross it high up to 1200hz.
Thank you gentlemen.
Godzilla,
Are you using this Dayton APA150 as a stereo sub amp (meaning the amp can provide power for 2 of your H enclosures) instead of using 2 plate amps. I may just do the same as it is more convenience, cheaper and as you said, I dont have to build a box to put the plate amps into.
MJK, do you think I can use your H frame design and cross it high up to 1200hz.
Thank you gentlemen.
Re: Dayton APA150
No, I do not believe that will work. You will encounter the fundamental standing wave just above 200 Hz. Figure 17 in my write-up for the H frame shows that the response startes to roll-off just above this frequency. Using a low crossover frequency is one of the keys to making this design work.
tnc said:
No, I do not believe that will work. You will encounter the fundamental standing wave just above 200 Hz. Figure 17 in my write-up for the H frame shows that the response startes to roll-off just above this frequency. Using a low crossover frequency is one of the keys to making this design work.
The amp has a switch on the back to run mono or stereo. I set it to stereo. Beware! The volume knob is too sensitive. The amp had to be sent back for a resistor to be added so the volume knob could be turned without the amp putting out full power almost immediately. I hope it helps and will report back once my amp returns.
Not sure how to calculate OB size. I guess the OB only needs to get down to 200hz to match with the H-frames. Probably a simple plank with a proper base would work. Martin made his about the same width as the H-frames. Maybe you can be creative with bendable wings? This classic Infinity speaker came to mind when thinking of a design for the H-frames plus OB. Just a thought.
http://www.anello.de/Images/RS_2.5_3.jpg
http://www.bobbyshred.com/images/RS25sm.jpg
Taking up no additional floor space is a great thing. But for now i will live with my BIBs + H-frames and enjoy the music.
Godzilla
Not sure how to calculate OB size. I guess the OB only needs to get down to 200hz to match with the H-frames. Probably a simple plank with a proper base would work. Martin made his about the same width as the H-frames. Maybe you can be creative with bendable wings? This classic Infinity speaker came to mind when thinking of a design for the H-frames plus OB. Just a thought.
http://www.anello.de/Images/RS_2.5_3.jpg
http://www.bobbyshred.com/images/RS25sm.jpg
Taking up no additional floor space is a great thing. But for now i will live with my BIBs + H-frames and enjoy the music.
Godzilla
Please keep in mind that the following design variables were accounted for in the design of my H frame / OB system.
Size and shape of the open baffle.
Location of the driver on the baffle.
Height of driver from the floor.
Crossover frequencies - both high and low pass.
Crossover slopes - 12 dB/octave.
Relative efficiencies of the H frame and driver.
If you significantly change one of these variables you will impact the systems response and will need to revisit the design. Maybe the design can be improved but winging it is probably not a great plan of attack.
Size and shape of the open baffle.
Location of the driver on the baffle.
Height of driver from the floor.
Crossover frequencies - both high and low pass.
Crossover slopes - 12 dB/octave.
Relative efficiencies of the H frame and driver.
If you significantly change one of these variables you will impact the systems response and will need to revisit the design. Maybe the design can be improved but winging it is probably not a great plan of attack.
Thanks MJK and Godzilla. I have put in an order for 2 Goldwood 18", and 2 Lil Buddy. I plan to do the MJK's H frame for the Goldwood and use the Lil Buddy with the Econowave Project mounting on separate OB baffle and they will be sitting on top of the H frame. Now I have to find someone in Texas to build the H frame for me.
>>> and 2 Lil Buddy...
tnc, that's what i have rolling around in my brain to build too. Please keep me posted on your progress. Especially what you think of the Lil Buddies on OB. I think you will end up with an absolutely amazing sounding system!
godzilla3@hotmail.com
Godzilla
tnc, that's what i have rolling around in my brain to build too. Please keep me posted on your progress. Especially what you think of the Lil Buddies on OB. I think you will end up with an absolutely amazing sounding system!
godzilla3@hotmail.com
Godzilla
tnc said:
Hi,
I have tried the econowave project combo, it uses selenium compression driver and jbl horn, the combo sounds ok, if you are sensitive to high freq., then the combo is not suitable to you. Selenium driver uses Titanium diaphragm and some people cannot tolerate the high freq., zing it produces.
An alternative I am using is B&C De250 compression driver and RCF H100 horn, this combo I am using now out performs the above combo. DE250 using Polyimide diaphragm. DE250 is used by many happy people(Gedlee included) and I understand it is still expensive $150 each from PE parts. This combo needs little equalization, I use active x-over and it is easy for me.I gurrantee you will be happy with them. Dynamic and open and more importantly no HF zing.
Cheers.
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