Well after hearing so many good reports I thought I would try a set of the CSS FR125s. I normally listen to a set of JBL4412a, with which I have a love hate relationship. They are really loud, and some cds sound great on them. But mostly they sound hard, shouty and boxy, the tweeters are pretty awful.
I made a couple of 7l BR boxes for the fr125s, rear ported. I calculated the vents in WINISD around 50hz, but they turned out much lower, around 35hz. They will eventually be aperiodic or sealed, running with subs.
I have chemical sensitivities, so I am not allowed to work with mdf or plywood. Thus the cabinets are reclaimed hardwood. I haven't made boxes for 10 years or so, so they are a little rough. Cutting it all with a handsaw didn't help the squareness either. I've now learned that hardwood is terrible for speaker cabinets, it really sings! Looks nice though...
How do they sound? I think I can live with these, for a while anyway. Vocals sound really nice. They will need some BSC or a notch filter, they are a bit thin sounding on some cds. Might be the 1k hump that Vikash found in his design. (any assistance in this area would be appreciated, I'll be using active circuits) Bass is amazing for a small driver, but only at very low volumes. I'll need to high pass these to make them usable for my normal listening levels.
I like how they disappear, and the top end is really easy on the ear. It means I can listen to cds now that I couldn't stand on the JBLs. They were dictating what kind of cds I was listening too, and that was no good.
I don't like the off axis performance however, they beam really badly, whether that will be a problem in the long run I'm not sure.
They are for certain one hell of a bargain. Getting this kind of sound out of a $220AUD box is quite amazing. (Thanks to Dan at Darcher Audio for supplying the drivers)
Adam
I made a couple of 7l BR boxes for the fr125s, rear ported. I calculated the vents in WINISD around 50hz, but they turned out much lower, around 35hz. They will eventually be aperiodic or sealed, running with subs.
I have chemical sensitivities, so I am not allowed to work with mdf or plywood. Thus the cabinets are reclaimed hardwood. I haven't made boxes for 10 years or so, so they are a little rough. Cutting it all with a handsaw didn't help the squareness either. I've now learned that hardwood is terrible for speaker cabinets, it really sings! Looks nice though...
How do they sound? I think I can live with these, for a while anyway. Vocals sound really nice. They will need some BSC or a notch filter, they are a bit thin sounding on some cds. Might be the 1k hump that Vikash found in his design. (any assistance in this area would be appreciated, I'll be using active circuits) Bass is amazing for a small driver, but only at very low volumes. I'll need to high pass these to make them usable for my normal listening levels.
I like how they disappear, and the top end is really easy on the ear. It means I can listen to cds now that I couldn't stand on the JBLs. They were dictating what kind of cds I was listening too, and that was no good.
I don't like the off axis performance however, they beam really badly, whether that will be a problem in the long run I'm not sure.
They are for certain one hell of a bargain. Getting this kind of sound out of a $220AUD box is quite amazing. (Thanks to Dan at Darcher Audio for supplying the drivers)
Adam
You call that rough? You've done a very good job I think, especially with a handsaw. You've even rebated the driver.
Sorry I can't help you with the beaming issue, you may want to check out the Mamboni/ENABL thread, a little bit of paint shouldn't hurt the drivers and the theories make sense. It should smooth the rough edges off at least.
You probably know already but you should avoid pine, it has a lot of formaldehyde.
Try putting a cardboard box over them to protect the cones then a thick blanket over the whole lot and give them a good thrashing for a day or so. I thought driver run-in was rubbish until I had a pair of fostex fullrangers.
Nice job Adam,
Sorry I can't help you with the beaming issue, you may want to check out the Mamboni/ENABL thread, a little bit of paint shouldn't hurt the drivers and the theories make sense. It should smooth the rough edges off at least.
You probably know already but you should avoid pine, it has a lot of formaldehyde.
Try putting a cardboard box over them to protect the cones then a thick blanket over the whole lot and give them a good thrashing for a day or so. I thought driver run-in was rubbish until I had a pair of fostex fullrangers.
Nice job Adam,
Hi Adam, surely you jest. They look stunningFoxx510 said:
I did some active filters for the FR125S here: http://www.madaboutsound.com/bravura_fr125S_speaker_design.asp
The values would need tweaking for your cabinet, but it might give you some ideas nonetheless.
Vikash
Thanks. I just would have liked them to be a bit squarer, and the router got away on me a few times... You will notice I used some of the Mad About Sound speaker fasteners, they are great!
I'll breadboard some filters next week. I'm pretty new to active filter design, I'll have a good look over your bravura filter Vikash. If you have time, it would be great if you could briefly describe what each opamp section does according to its IC tag(ie IC1, IC2). I'll be starting off with a buffer and an adjustable BSC compensation circuit, then later adding a 24db octave linkwitz-riley highpass at around 100hz when the subs are built.
Adam
I'll breadboard some filters next week. I'm pretty new to active filter design, I'll have a good look over your bravura filter Vikash. If you have time, it would be great if you could briefly describe what each opamp section does according to its IC tag(ie IC1, IC2). I'll be starting off with a buffer and an adjustable BSC compensation circuit, then later adding a 24db octave linkwitz-riley highpass at around 100hz when the subs are built.
Adam
Hi,
IC1A - Input Buffer and DC block
IC2B - 12db Hi pass filter
IC2A - Notch filter (BS filter ~ 1Khz)
IC2B - Notch filter (Peak at ~6.5kHz)
IC3A - Notch filter (Peak at ~12kHz)
IC4A - Peak filter (Dip at ~ 10kHz)
IC3B - Simulated inductor for peak filter
IC4B - Output Buffer
This thread will highlight the design for you: http://www.diyaudio.com/forums/showthread.php?s=&threadid=100525&highlight=
V
IC1A - Input Buffer and DC block
IC2B - 12db Hi pass filter
IC2A - Notch filter (BS filter ~ 1Khz)
IC2B - Notch filter (Peak at ~6.5kHz)
IC3A - Notch filter (Peak at ~12kHz)
IC4A - Peak filter (Dip at ~ 10kHz)
IC3B - Simulated inductor for peak filter
IC4B - Output Buffer
This thread will highlight the design for you: http://www.diyaudio.com/forums/showthread.php?s=&threadid=100525&highlight=
V
That looks like a raw response to me. The Bravura's measure like this:
Your measurments look good. If you apply the transfer function as shown to your measurements, you should get a flat response all the way through
An externally hosted image should be here but it was not working when we last tested it.
Your measurments look good. If you apply the transfer function as shown to your measurements, you should get a flat response all the way through
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