Yes, that would mean needing to start the next set wouldn't it, where would you find the room?? LOL
We are renovating here, which is why I have no speaker projects on the go, you should see our house.
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Ok, back to the speakers... I've just measured the one speaker again only to find the peak has shifted down and been reduced in amplitude.
Of course previously I'd measured without the usual piece of foam I install behind the mid driver. I'd removed those to work on the crossovers and hadn't put them back!!
I think the moral of this tale is I can't really effectively EQ out such a tiny peak but considering the general response maybe removing some sound from this range will reap rewards. Of course only listening to music will prove its true efficacy and I'll need to upgrade the components too, ideally. The coil is of good quality but the cap is a bipolar electrolytic
I've tried a couple of filters as suggested.
Please could you suggest what component to change in order to reduce the upper limit of the filter? Otherwise it's looking really good on paper to me!!
Of course previously I'd measured without the usual piece of foam I install behind the mid driver. I'd removed those to work on the crossovers and hadn't put them back!!
I think the moral of this tale is I can't really effectively EQ out such a tiny peak but considering the general response maybe removing some sound from this range will reap rewards. Of course only listening to music will prove its true efficacy and I'll need to upgrade the components too, ideally. The coil is of good quality but the cap is a bipolar electrolytic
I've tried a couple of filters as suggested.
Please could you suggest what component to change in order to reduce the upper limit of the filter? Otherwise it's looking really good on paper to me!!
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No, perhaps that would be enlightening for me. I do have a thick carpet and a short measuring distance so I'm not exactly sure what sort of floor-bounce effect I have in my measurements.
I've toyed with the capacitor value in this filter, trying 22uF/33uF/47uF and 94uF. 47uF gives the smoothest curve, it's really good I think.
The difference with this filter in place and not is night and day on pink noise. It's like removing a grating overlay, which sounds resonant - only obvious when removed.
I'll get a bypass cap on the 47uF and get the other speaker done and play some music next!!!!
The difference with this filter in place and not is night and day on pink noise. It's like removing a grating overlay, which sounds resonant - only obvious when removed.
I'll get a bypass cap on the 47uF and get the other speaker done and play some music next!!!!
Oops, forgot the graph.
I've pretty much gone for the black trace there, except I upped the resistor to 3.9R to make the effect milder. I don't like filtering things too strongly and it seemed excessive to hoover up so much energy like that.
Looks like about +-3dB across 100hz - 5khz, which I think is not bad for any speaker in-room. I also recognise that on-axis response of just one speaker is only one measure of quality and not necessarily as relevant as it may seem.
Music sounds great though, definitely better with what I've played so far.
I've pretty much gone for the black trace there, except I upped the resistor to 3.9R to make the effect milder. I don't like filtering things too strongly and it seemed excessive to hoover up so much energy like that.
Looks like about +-3dB across 100hz - 5khz, which I think is not bad for any speaker in-room. I also recognise that on-axis response of just one speaker is only one measure of quality and not necessarily as relevant as it may seem.
Music sounds great though, definitely better with what I've played so far.
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I keep thinking it's nearly done. Maybe it finally is... other than an active crossover and foam inserts on the tweeters!!
very nice result,
I do not understand the HF driver has such low efficiency? Cause by your own wave guide?
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It's slightly surprisingly low but do bear in mind the mid is quite an efficient driver. The notch filter is also eating up some output. Both of these drivers are WAY louder than the woofers, which are now on their own amplifier.
I realise there are some oddities and my measurements are probably not to be relied upon too heavily but the speakers do sound excellent now and the sound does seem to tally with the axial response.
Thanks again for the filter suggestion, it's brought a quite obviously more balanced sound.
I realise there are some oddities and my measurements are probably not to be relied upon too heavily but the speakers do sound excellent now and the sound does seem to tally with the axial response.
Thanks again for the filter suggestion, it's brought a quite obviously more balanced sound.
There's also a bit of foam wedged in around the outside portion of the phase plug, dropping efficiency a little - mainly to counter the rising response my waveguides cause.
After mainly just listening and enjoying my speakers I decided to do a little bit of tweaking today. I altered the capacitor value of the 2nd pole on the low-pass filter of the woofers. I increased it from 150uF to 680uF. To counteract the reduce efficiency I adjusted the amplifier levels to suit. What I was looking for was smoother and deeper bass with less midrange coming through the woofers.
The sound is ever so slightly soft down there, which I think can be attributed to the woofers (cheap and plastic) and the tiny room (not conducive to exciting bass). Otherwise, the result is very pleasing, with a fuller sounding bottom end and, to my surprise, a more coherent sound top to bottom.
Edit: there's also a slight change to the tweeter's notch filter, whereby 10R is replaced by 7R. The extra "sparkle" up top was really needed and having a friend round to listen confirmed this as he felt the sound was excellent barring a slightly dull treble.
The sound is ever so slightly soft down there, which I think can be attributed to the woofers (cheap and plastic) and the tiny room (not conducive to exciting bass). Otherwise, the result is very pleasing, with a fuller sounding bottom end and, to my surprise, a more coherent sound top to bottom.
Edit: there's also a slight change to the tweeter's notch filter, whereby 10R is replaced by 7R. The extra "sparkle" up top was really needed and having a friend round to listen confirmed this as he felt the sound was excellent barring a slightly dull treble.
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Tonight I've tweaked the tweeter notch filter to give a flatter response. I had to wind a tiny custom inductor to get the narrow notch required.
I've also attached a picture of the response as it is now. It's much flatter than it used to be and it does sound better too, though I've not listened much with the notch changes and it's quite late now.
I've also attached a picture of the response as it is now. It's much flatter than it used to be and it does sound better too, though I've not listened much with the notch changes and it's quite late now.
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I guess the response is +-2dB for almost the entire response now. I'm not sure how relevant that is but it feels like progress. Surely the speakers are just about done now 😉
Your entire mid range is nice flat and no XO in that area will certainly sound very nice simonty when the off axes are the same quality.
Good work!
Thanks guys. Since then I did take the tweeter level down a little as it's not really high enough quality to be heard prominently. I have better enjoyment with it slightly duller up top.
interesting/excellent project dude, i'm also living in sheffield and like to build speakers. Until recently i've been mainly interested in building PA systems, my current system is actually the same set up driver (size) wise for the mid tops, two 12" beyma sm112n in a reflex cabinet, eminence 8mr sealed back 8 on a horn and a B&C de250 on an 18sound oblete spheroid waveguide. Also got some beyma 12lx60 drivers that i was using in modified decware wicked ones. old system pic http://i300.photobucket.com/albums/nn7/danger_noise/tinnitus20508114.jpg
it's been painted since and is generally more strapped together
thinking about it i've also got some celestion ubermini 1" neodymium compression drivers that are earmarked for some 12 and 1 monitors kicking around that may be worth a shot as they're only about 30 quid a go and sound quite sweet. http://professional.celestion.com/pro/pdf/CDX1-1425.pdf
If you're interested in comparing some of these sometime in the new year (particuarly the comp drivers which may well prove easier to mount) i'm well up for it. Always good to meet more local speaker geeks to talk audio with, specially if you get to hear new stuff in the process 🙂
it's been painted since and is generally more strapped together
thinking about it i've also got some celestion ubermini 1" neodymium compression drivers that are earmarked for some 12 and 1 monitors kicking around that may be worth a shot as they're only about 30 quid a go and sound quite sweet. http://professional.celestion.com/pro/pdf/CDX1-1425.pdf
If you're interested in comparing some of these sometime in the new year (particuarly the comp drivers which may well prove easier to mount) i'm well up for it. Always good to meet more local speaker geeks to talk audio with, specially if you get to hear new stuff in the process 🙂
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