Dr.EM said:
Hi Dr.EM,
Nice to hear from you. I have taken an extended break from building the amps due to extreme fear they will start misbehaving again (if you have seen my active amp thread, you know what I'm referring to).
I have one channel complete and the low-pass and mid-pass on the other channel done. I have been trying to force myself to finish it but I've had very little free time on my hand lately (busy with work/renovation here at home). I've also been distracted by other projects:http://www.diyaudio.com/forums/showthread.php?s=&postid=1356929#post1356929
I am actually considering using the active amp boards as filters only and building six of the amps detailed in the thread above.
Chip amps have lost their shine for me, maybe unjustly.
To be honest, about a week ago I built two passive crossovers for these speakers, just so I could use them. I'd gotten sick of the temporary ones I was using.
The passive crossover is a very poor substitute though - there is no comparison at all to the way it sounds with the active amplification.
I will find the motivation to complete the amp eventually, as I always finish what I start.
Tonight I have the actives amp finished and I'm taking these speakers for a proper test drive.
Took a little while to get the levels correct - the midrange driver is at least 3db more sensitive than the tweeter (90db) and the woofer (90db). To equalize the midrange I reduced the level pot on the amp by about 1/5th. I used the TrueRTA tone generator and step it up in frequency from 20Hz to ~11KHz (where I could no longer hear ).
Response was very even through the crossover ranges. This is by ear, as I don't have an SPL meter.
I hear good bass response down to ~35Hz, where it starts to roll off. This is better than I expected from an 8" in a 30 litre sealed enclosure.
Took a little while to get the levels correct - the midrange driver is at least 3db more sensitive than the tweeter (90db) and the woofer (90db). To equalize the midrange I reduced the level pot on the amp by about 1/5th. I used the TrueRTA tone generator and step it up in frequency from 20Hz to ~11KHz (where I could no longer hear
).Response was very even through the crossover ranges. This is by ear, as I don't have an SPL meter.
I hear good bass response down to ~35Hz, where it starts to roll off. This is better than I expected from an 8" in a 30 litre sealed enclosure.
The foam wedge treatment inside the midrange chamber seems to be very effective. Once I had the mid "padded" down, it blended smoothly with the woofer and tweeter.
I have a few songs I like for judging the midrange quality. Oddly enough, one of these is Janis Joplin's "summertime". As harsh as she sounds, she shouldn't sound harsh (that makes sense to me ). These mids, she's whispering in my ear.
I like Al Stewart with "Year of the Cat" as he's slightly nasal and sibilant. Glad to report he sounds normal.
Amy Lee has a great voice, and she sounded amazing on "My Immortal" - I felt chills.
The greatest rock singer of all time, Freddie Mercury, with "The Show Must Go On" and "Too Much Love Will Kill You". I swear, he was in the room with me.
Diana Krall, of course, with "Autumn Leaves".
Chicago's "Questions 67 And 68" - Peter Cetera's voice and the horns. Sparkling.
"It Was A Very Good Year" and "New York, New York" by Frank Sinatra.
Burton Cummings "I'm Scared".
I'm pleased. At this point I don't feel there is much to improve upon for the midrange. More listening tomorrow evening though.
I have a few songs I like for judging the midrange quality. Oddly enough, one of these is Janis Joplin's "summertime". As harsh as she sounds, she shouldn't sound harsh (that makes sense to me
). These mids, she's whispering in my ear.I like Al Stewart with "Year of the Cat" as he's slightly nasal and sibilant. Glad to report he sounds normal.
Amy Lee has a great voice, and she sounded amazing on "My Immortal" - I felt chills.
The greatest rock singer of all time, Freddie Mercury, with "The Show Must Go On" and "Too Much Love Will Kill You". I swear, he was in the room with me.
Diana Krall, of course, with "Autumn Leaves".
Chicago's "Questions 67 And 68" - Peter Cetera's voice and the horns. Sparkling.
"It Was A Very Good Year" and "New York, New York" by Frank Sinatra.
Burton Cummings "I'm Scared".
I'm pleased. At this point I don't feel there is much to improve upon for the midrange. More listening tomorrow evening though.
Glad to hear you've got it going . Being happy with midrange is a really significant factor. It seems to be the most sensitive element to sutble changes and the most objectionable when its wrong! My mids are suffering from poor (very poor) enclosures and it really shows. Might give your technique a try
. Being happy with midrange is a really significant factor. It seems to be the most sensitive element to sutble changes and the most objectionable when its wrong! My mids are suffering from poor (very poor) enclosures and it really shows. Might give your technique a try 
Dr.EM said:Glad to hear you've got it going
Thanks DrEM,
I'm not sure if the method is 100% effective. I have been listening again this evening and I have connected my 10 band equalizer, just to see how this piece of equipment sounds with this setup. All other sliders flat, I cut 500Hz by 2db and hear an improvement. More listening is definitely needed.
ShinOBIWAN said:Great stuff John and congrats. Any more pics for us all?
Oh and BTW, with a little more tweaking I'm sure they won't end up in the fireplace
Hi Ant,
Sorry, no pics. Been too busy lately to churn out more CG.
Tweaking will happen, but I'm not sure it will be enough to save them. One thing in their favour is that my fireplace is gas.
Listening continues. It's a bit distracting how much detail I'm hearing with these that I'd not noticed before. Everything is much clearer and It's showing the good, bad and ugly in my music collection. I have a mountain of MP3's, most of these sound like complete garbage on these speakers. CD's(played on the computers drive) sound, for the most part good. I haven't listened to any vinyl yet (I will on the weekend, if I'm not working).
As mentioned above, I'm finding a little harshness in the lower midrange. I'm not sure if the addition of a little stuffing in the midrange chamber would tame that.
Bass from these is much better than I expected. I thought I would need subs to augment their production, but I don't think so now. Bass is fast and accurate, with no signs of distortion, even at high volume. I didn't break the bank on these woofers (on sale for $42.00 from Solen - still available).
Merry Christmas to all
Hi MJL, I just noticed this thread for the first time and must compliment you on a great looking enclosure.I really like the way you were able to curve the baffle.Nice work.
I have a similar 3 way active set up using all SEAS drivers (P21REX,CB17RCY/P and H1212 tweets) although I'm going to replace the P21REX's (using in another project)with a pair of the CA21REX's that Solen have on sale.
I have a similar 3 way active set up using all SEAS drivers (P21REX,CB17RCY/P and H1212 tweets) although I'm going to replace the P21REX's (using in another project)with a pair of the CA21REX's that Solen have on sale.
F1 FAN said:
Thanks F1,
The CA21REX is supposed to be 93db sensitivity (though I doubt that, more like 90). That puts it 3-6db more sensitive than the P21REX, with better power handling and a slightly lower Fs. More versatile, suitable for sealed or vented box. Plus it's cheap - the best part.
These make an excellent woofer for a mid sized 3-way IMO.
Good luck with your speaker projects.
Nico Ras said:
Thanks Nico,
No, I'm not very interesting. I just have some enthusiasm for the hobby and the good fortune to be in a position to pursue it.
My skills are balanced by all of the stupid mistakes I make.
The system grows. This weekend I will build a permanent phono preamp and etch at least one of the boards for the new amp design.
And some more listening, of course.
Greetings,
I have had almost 2 weeks to listen to these speakers. I am not happy with the midrange. It's too "in your face" and something's not quite right. At first, I thought it was that these drivers are too efficient and that reducing the output to them from the active amp would tame them a bit. This just reduced their volume, not their "forwardness". They have the cheap transistor radio quality about them that's ruining my satisfaction with these speakers.
I first thought that it might be my special interior treatment of the chamber was not doing enough, but removing the drivers and adding stuffing did nothing. I also, for lack of anything else to try, reversed the polarity. This didn't help at all.
Followers of this thread will remember that I had no solid info on these drivers and only had my Speaker Workshop measurements to go by. I think the frequency response is peaked, and that's what I'm hearing.
I was looking around at Solen for a possible replacement and see the Vifa P11WH008 is on sale. I used the P13WH008 on a previous project and found the results to be very good.
The P11 would be a direct fit in the existing driver hole and recess (125mm diameter).
I attach the spec sheet for this driver. Frequency response is perfect for this speaker.
I have had almost 2 weeks to listen to these speakers. I am not happy with the midrange. It's too "in your face" and something's not quite right. At first, I thought it was that these drivers are too efficient and that reducing the output to them from the active amp would tame them a bit. This just reduced their volume, not their "forwardness". They have the cheap transistor radio quality about them that's ruining my satisfaction with these speakers.
I first thought that it might be my special interior treatment of the chamber was not doing enough, but removing the drivers and adding stuffing did nothing. I also, for lack of anything else to try, reversed the polarity. This didn't help at all.
Followers of this thread will remember that I had no solid info on these drivers and only had my Speaker Workshop measurements to go by. I think the frequency response is peaked, and that's what I'm hearing.
I was looking around at Solen for a possible replacement and see the Vifa P11WH008 is on sale. I used the P13WH008 on a previous project and found the results to be very good.
The P11 would be a direct fit in the existing driver hole and recess (125mm diameter).
I attach the spec sheet for this driver. Frequency response is perfect for this speaker.
Attachments
peufeu said:
Hi,
I am in the process of rebuilding my Speaker Workshop test gear, and don't have the facility to test yet.
I do know the midrange doesn't sound right, and I thought that going with a driver that I know about (and have the specs for) will be an improvement.
These mids (the MAX's) cost me next to nothing. They were used, and I'm no sure that they weren't abused (although they don't sound like it).
I have used an equalizer to cut some frequencies and it made a definite improvement to how the midrange sounds. This is the basis for my belief the response is peaked (maybe around 1K).
I'm paying now for not properly trying these drivers before I committed to using them. Luckily, the P11 is only $33 each and I believe they are well worth that.
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