Hi bthp223,
I like your forum name. Maybe I can help with the photo upload problem. I use my iPhone for most of my photo uploads. When you want to reply to a thread click on the Go Advanced button. Then under Additional Options, click on Manage Attachments. The Manage Attachments window will open. Click on Choose File. On my iPhone a window will open giving me options to take a photo or go to photo library. Choose the photo you want to upload. After choosing the photos you want attached, click on the Upload Button in the lower right corner. Then click on Close this Window. Now you should be back to the Reply to Thread window. Click on the Preview Post button, so you can see if the photos attached properly. I hope this was helpful. You may have already tried it this way and still won't work, in that case it could be a software issue. Good luck with your project.
Regards,
Matt
A major mistake is the small cabinet volume of 55 litres for the two woofers. Each has a VAS of 150 lit, so if one is to expect a good LF performance, then there shoud be available about 150-200 or more. That the woofers are 8 ohm is good. Small cabinet volume pushes the Fs of driver in a box rather high and this makes the usual LP woofer filter react in a way that the FR rises and the bass is even more down by looking at the new reference SPL.
Whenever you make a new design, never ever buy the expensive filter parts, not until it's perfected enough to be worthy of it.
Whenever you make a new design, never ever buy the expensive filter parts, not until it's perfected enough to be worthy of it.
This!! When I first started in this hobby in the 90's it was really expensive to have measurement equipment, but now it's cheap. I really think it should be the first thing you should do if you take audio seriously.
dont worry, been moving country, buiding houses, at last maybe get to finish my speakers. Posted some threads reg interference and transformer hum/buzz. Money, hm.
Anyway, I fond a mob in Italy, that makes audio switsch mode power supplies.
And for active crossovers, try miniDSP, there is a 2x4 that will be enough for 2 off 2 pass speakers. There is a low and a high spec one, high spec one can bend back the phase (make it linear). Or if you not into DIY electronics, just get a ready built actie xover
Anyway, I fond a mob in Italy, that makes audio switsch mode power supplies.
And for active crossovers, try miniDSP, there is a 2x4 that will be enough for 2 off 2 pass speakers. There is a low and a high spec one, high spec one can bend back the phase (make it linear). Or if you not into DIY electronics, just get a ready built actie xover
Argh, I can feel your frustration... Been there, as much of us have been I think. Sadly I don't have the knowledge to help you with measurements and crossover, but I think there are people who are willing to help you, maybe even locally (hifi-club or something).
Or call Troels and see if with some minor adjustments/extra stuff you can build one of his designs. They are really good: I build a DTQWT mk III and it sounds beautiful. It can compare favourably to very expensive speakers. Maybe an ATS4 or something?
Or call Troels and see if with some minor adjustments/extra stuff you can build one of his designs. They are really good: I build a DTQWT mk III and it sounds beautiful. It can compare favourably to very expensive speakers. Maybe an ATS4 or something?
Scanspeak
R2904-700000 tweeter-4
18W/4531G00 midrange-4
26W/8534G00-8
Cabinet
Lower bass 55 liter
Upper tweeter/midbass 21 liter.
All a complete muddle, IMO. But 55L ought to work for a 10" bass. The ABR is a bit desperate, isn't it? 21L seems a lot for a 6" mid too.
That doesn't actually look like the R2904-7000 to me. More like a soft dome. But whatever.
Couple of similar projects:
Ekta-Grande
Jensen-1071
Your first mistake was getting a 6" 4 ohm midrange, which will cause some severe low impedance issues. Your second mistake was getting a ring radiator, which really needs to be crossed at 3.5kHz, IMO.
One of them has gotta go.
R2904-700000 tweeter-4
18W/4531G00 midrange-4
26W/8534G00-8
Cabinet
Lower bass 55 liter
Upper tweeter/midbass 21 liter.
All a complete muddle, IMO. But 55L ought to work for a 10" bass. The ABR is a bit desperate, isn't it? 21L seems a lot for a 6" mid too.
That doesn't actually look like the R2904-7000 to me. More like a soft dome. But whatever.
Couple of similar projects:
Ekta-Grande
Jensen-1071
Your first mistake was getting a 6" 4 ohm midrange, which will cause some severe low impedance issues. Your second mistake was getting a ring radiator, which really needs to be crossed at 3.5kHz, IMO.
One of them has gotta go.
A 6.5" midwoofer working nicely enough with a 1" soft dome tweeter in an actively crossed DIY 3 way with the woofers switched off (crossover -6dB =150Hz). Measurement made using a Focusrite 2i2 and a calibrated Earthworks mic at 1.5m off the baffle and about 15 degress off axis horizontally but in vertical alignment with the tweeter:
There's a phase shifter in front of the tweeter and baffle step compensation. All analogue. No DSP or other PEQ etc.
The thing that looks like a bump at 500Hz is entirely dependent on the mic position and is not present at the sweet spot.
7 months is nothing. That took about 7 years!
An externally hosted image should be here but it was not working when we last tested it.
There's a phase shifter in front of the tweeter and baffle step compensation. All analogue. No DSP or other PEQ etc.
The thing that looks like a bump at 500Hz is entirely dependent on the mic position and is not present at the sweet spot.
7 months is nothing. That took about 7 years!
Yeah, the 18W/4531 IS an odd choice in a 3-way, I am listening to a pair of them right now.
On the other hand, it IS a pretty awesome mid-woofer. It is ideal for 2-ways if you can give it the cabinet volume it needs.
Perhaps it's size will help transparency by controlling the radiation pattern.
A slight negative is it has a little more distortion at the top of it's usable range. A smaller mid would have avoided this altogether.
On the other hand, it IS a pretty awesome mid-woofer. It is ideal for 2-ways if you can give it the cabinet volume it needs.
Perhaps it's size will help transparency by controlling the radiation pattern.
A slight negative is it has a little more distortion at the top of it's usable range. A smaller mid would have avoided this altogether.
Beautiful cabs!
Individually great drivers, altho a slightly odd combo. I have the 26W and also messed my project up.. not the drivers fault at all. It works best sealed but a PR is a neat idea to reduce cab volume (needs a massive box ported)
I'd have placed the bass driver at the bottom to keep 2pi(for better sensitivity) and PR at the back (which you cd still do perhaps)
Individually great drivers, altho a slightly odd combo. I have the 26W and also messed my project up.. not the drivers fault at all. It works best sealed but a PR is a neat idea to reduce cab volume (needs a massive box ported)
I'd have placed the bass driver at the bottom to keep 2pi(for better sensitivity) and PR at the back (which you cd still do perhaps)
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