cnclld said:
I understood, I was just adding to.
(..though I should have clarified that the large enclosure volume was not primarily striving for pattern control.)The mid-range pattern control is something I recently recommended for use with CD-type waveguides. It's need for a smaller enclosure/low loss resistance relates to a need for increased pressure for the reverse-phase wave. Altering not simply the volume of the enclosure, but particularly the depth of the enclosure alters the level of pressure for this reverse-phase wave at differing freq.s. (i.e. less depth generally equals greater pressure at higher freq.s.)
My Pluto speakers. Designed by http://www.linkwitzlab.com/index.html build by me.
Attachments
Ok, here goes my (updated) system.
2x Mission 760i (mains)
1x Wharfedale Modus (centre speaker)
2x cheap 2-way speakers (rears)
1x Sub (2 DVC 8"s 42L, LT to f3@ 28Hz)
Powered by: All-in-one 2x75W stereo (mains)
Cambridge Audio A1, with Beefed up PSU, destroyed tone controls (used as XO and sub level) - sub and centre
Something old I pulled out of the loft - Rears.
Total system power 270W, Modelled frequency response - -3dB at 28Hz, not sure on upper limit, probably on the Missions... Talking of which... Those Missions had typical Mission syndrome, where they sound good from 2 months old to 2 years old, after which they sound tired. So, after fiddling with the XO circuit - there was a resistor going to the tweeter, which I put in parallel with a few more, using trial and error, and I got it right-ish.
My old, SPL based system consisted of 2x 3 way pioneer speakers (8" paper cone, 4" mid, 2" tweeter) and a pair of sony 3-ways, with a 6" woofer. Both pairs older than me, passed on from neighbours who'd heard I was into speakers.
Not bad for a 15 year old, eh?
Chris
2x Mission 760i (mains)
1x Wharfedale Modus (centre speaker)
2x cheap 2-way speakers (rears)
1x Sub (2 DVC 8"s 42L, LT to f3@ 28Hz)
Powered by: All-in-one 2x75W stereo (mains)
Cambridge Audio A1, with Beefed up PSU, destroyed tone controls (used as XO and sub level) - sub and centre
Something old I pulled out of the loft - Rears.
Total system power 270W, Modelled frequency response - -3dB at 28Hz, not sure on upper limit, probably on the Missions... Talking of which... Those Missions had typical Mission syndrome, where they sound good from 2 months old to 2 years old, after which they sound tired. So, after fiddling with the XO circuit - there was a resistor going to the tweeter, which I put in parallel with a few more, using trial and error, and I got it right-ish.
My old, SPL based system consisted of 2x 3 way pioneer speakers (8" paper cone, 4" mid, 2" tweeter) and a pair of sony 3-ways, with a 6" woofer. Both pairs older than me, passed on from neighbours who'd heard I was into speakers.
Not bad for a 15 year old, eh?
Chris
Here is my current HT/Music system. Speakers are omni with vifa drivers (P17 + D25) passive crossover 2nd order @ 3.5k. Subs are 12" Rythmik sealed servo crossed at 80 Hz 4th order.
I use ultracurve for eq full range. This is a snapshot of typical settings to get it flat (see first snapshot)
then my "house curve" added to that: (second snapshot)
The current omnis are in prototype form, and I'll replace them with serious boxes later.
You can also see my current bandpass experiment with the vent removed.
About the omnis. Most of the vocal range is omni - below 1k. Above 1k they are omni in the horizontal plane only, so between 1k and xo @ 3.5k there is more sound directed at the ceiling. Above the crossover point it's probably not really omni due to the baffle. Subjectively I find as moving around the room, the midrange retains a very consistent character. I get the big sweet spot and sound stage of open baffles.
These speakers are an experiment, but I've decied to leave them in my system for a while. Normally I have OB prototypes.
There is more info on all this on my blog:
http://redspade-audio.blogspot.com/2009/08/welcome.html
Edit: sadly the pics don't seem to be working - probably due to blogspot image restrictions, but they are all there in the blog, and included as attachments.
I use ultracurve for eq full range. This is a snapshot of typical settings to get it flat (see first snapshot)
then my "house curve" added to that: (second snapshot)
The current omnis are in prototype form, and I'll replace them with serious boxes later.
You can also see my current bandpass experiment with the vent removed.
About the omnis. Most of the vocal range is omni - below 1k. Above 1k they are omni in the horizontal plane only, so between 1k and xo @ 3.5k there is more sound directed at the ceiling. Above the crossover point it's probably not really omni due to the baffle. Subjectively I find as moving around the room, the midrange retains a very consistent character. I get the big sweet spot and sound stage of open baffles.
These speakers are an experiment, but I've decied to leave them in my system for a while. Normally I have OB prototypes.
There is more info on all this on my blog:
http://redspade-audio.blogspot.com/2009/08/welcome.html
Edit: sadly the pics don't seem to be working - probably due to blogspot image restrictions, but they are all there in the blog, and included as attachments.
Attachments
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Nice!
I tried to post some comments on your site and they didn't quite make it..
Basic thoughts on design alterations are:
1. Use an eff. midrange in a moderate volume with a low tuning freq.. and no stuffing or wall lining. That should give you the clarity you are looking for. The B&C 6MD38 should work out well with it's rising response on axis up to 1.7 kHz, its overall smaller diameter (for an eff. midrange), and its eff. which will be "cut" on the listening axis by about -7 to -8 db (85 deg.s off-axis).
2. Consider the BG Neo 3PDR as a DIPOLE for the tweeter. (GR Resarch still has these with an open back). Use stuffing/padding on the tweeter baffle to absorb baffle effects.
3. Use a good eff. mid-bass driver (regardless of open baffle or enclosure). It still makes a substantial difference.
Anyway, nice write-up!
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Thanks Scott! I didn't know there was a problem with adding comments to my blog. Was there an error message?
The system as shown is experimental and temporary. I've looked at some efficient drivers along similar lines as an upgrade, although at this stage I'm looking at a Geddes Abbey approach, mains then becoming surrounds. AE drivers also have my attention.
The system as shown is experimental and temporary. I've looked at some efficient drivers along similar lines as an upgrade, although at this stage I'm looking at a Geddes Abbey approach, mains then becoming surrounds. AE drivers also have my attention.
I don't remember exactly what happened, though I do remember that drop down list and it quickly "barfing" after that with no way to retrieve the post by hitting the "back" button. (..I know, should have copied it to clip board before trying to post.)
If you are primarily interested in L&R HT loudspeakers then I think that Earl's approach is excellent. If you are more interested in music, then I'd suggest continuing "down" the radial "path".
D
Deleted member 108835
My first DIY system
Hey all.
These are my first DIY speakers, using 2 x XT25TG30-04 & 4 x 850439 MTM
The boxed are built using 30mm MDF with 22mm internal bracing and around 30L approx. The speakers just need a few coats of something/sanding and there finished.
My gear is...
CD = Marantz CD6002
AMP = Cambridge Audio Azure 640A
TUNER = Sansui T60
INTERCONNECT = Chord Cobra 3
PWR LEADS = Home made
Platforms = 18mm MDF with Ball Bearing spacers
Current XO is 12db LR @ 2500hz but i am currently designing a new one.
The sound so far is OK but I am looking forward to much better results with a new XO that has baffle step comp and impedance smoothing
Cheers Dean
Hey all.
These are my first DIY speakers, using 2 x XT25TG30-04 & 4 x 850439 MTM
The boxed are built using 30mm MDF with 22mm internal bracing and around 30L approx. The speakers just need a few coats of something/sanding and there finished.
My gear is...
CD = Marantz CD6002
AMP = Cambridge Audio Azure 640A
TUNER = Sansui T60
INTERCONNECT = Chord Cobra 3
PWR LEADS = Home made
Platforms = 18mm MDF with Ball Bearing spacers
Current XO is 12db LR @ 2500hz but i am currently designing a new one.
The sound so far is OK but I am looking forward to much better results with a new XO that has baffle step comp and impedance smoothing
Cheers Dean
Attachments
My system
Heresy(1968), Sony cdp, Diy SE EL84, Bottlehead pre.
http://www.youtube.com/watch?v=UZZ-GoltFfQ
Heresy(1968), Sony cdp, Diy SE EL84, Bottlehead pre.
http://www.youtube.com/watch?v=UZZ-GoltFfQ
Nice system Tim614...here is my system with DIY speakers.
http://www.youtube.com/watch?v=NyJomaPwkZs
http://www.youtube.com/watch?v=NyJomaPwkZs
Very nice and siple set up! Love them.
i have a laptop so i can really get the full effect, but i do have a pair of BLH
fostex same driver as yours sound real nice with my SE el84 but i dont have room for them in my living room so they stay in my bedroom.
here's a pic
Just finished my subwoofer as part of a year 12 project. I'm also making floor standing speakers, which i will post up eventually. My project is due today so i might not get photos until they have been marked, which will be around November.
For those interested, the front of the enclosure is covered in leather, and the rest in gloss black laminate. Eight chrome stands connect it to the base.
The box is a perfect cube at 360x360x360mm, and is lined with barium sound deadening material and acoustic tiles. There are also two internal braces, though they're not really that neccessary seeing as the driver is only an 8" HiVi D8G. It has an F3 of 35Hz.
I know you're probably thinking i'm an idiot for picking such a driver, but i didn't know anything about drivers at the time when i designed this project (when i was 15).
Also i was on a pretty tight budget and couldn't really afford anything serious.
I'm pretty happy with how it turned out. Hopefully it sounds good too.
For those interested, the front of the enclosure is covered in leather, and the rest in gloss black laminate. Eight chrome stands connect it to the base.
The box is a perfect cube at 360x360x360mm, and is lined with barium sound deadening material and acoustic tiles. There are also two internal braces, though they're not really that neccessary seeing as the driver is only an 8" HiVi D8G. It has an F3 of 35Hz.
I know you're probably thinking i'm an idiot for picking such a driver, but i didn't know anything about drivers at the time when i designed this project (when i was 15).
Also i was on a pretty tight budget and couldn't really afford anything serious.
I'm pretty happy with how it turned out. Hopefully it sounds good too.
