First, I wouldn't pay much attention to what a friend thinks of the speakers unless you think he has great taste and lots of experience with many speakers (the Bose setup suggests maybe not).
Second, keep in mind that you'lll hear nearly all the sound that comes out of a speaker no matter what direction it heads out of it -- the sound reflects off of stuff in the room, which isn't necessarily bad. Just because your on-axis windowed response (essentially, what the response would be in an anechoic chamber) is flat doesn't mean everything is ideal or perfect. And the speaker's response is going to be different measuring it from different angles.
Second, keep in mind that you'lll hear nearly all the sound that comes out of a speaker no matter what direction it heads out of it -- the sound reflects off of stuff in the room, which isn't necessarily bad. Just because your on-axis windowed response (essentially, what the response would be in an anechoic chamber) is flat doesn't mean everything is ideal or perfect. And the speaker's response is going to be different measuring it from different angles.
I've seen small two way speakers made from cement cinder blocks, with timber front and back: must be about the cheapest materials you can get and minimal woodworking! About $10 each from Bunnings.
I've thought of doing that provided I can find a way to remove the centre reinforcement piece and use it sealed with a Vifa BC25TG/Peerless 830656, which would fit. That plus I don't need any more speakers at the moment.
Geoff
I've thought of doing that provided I can find a way to remove the centre reinforcement piece and use it sealed with a Vifa BC25TG/Peerless 830656, which would fit. That plus I don't need any more speakers at the moment.
Geoff
@pulexirritans
I use the omnimic (with it's calibration file) at a distance of 16" on tweeter axis (learned from the method that toid uses) then take measurements from 1 metre away as well, to the sides and above the speaker, I then look at the spectral decay and also use DATS. I use the wharfdale to set the mic up, if I get a response that is the same as what others have tested I assume that if my speakers follow that and show a flat response that I'm pretty close, how good that method is I'm still unsure about but in my head it seemed ok. I still have a lot to learn with taking measurements though, but I have the basics down. I have struggled to find tutorials or books that go into every aspect of measuring, there is so much to it and very few places to learn it, i just don't have the time to trawl the internet for pieces of info and then try to put it all together, I'd rather pay for an in depth tutorial that teaches me the rest of what I need to know, I just don't know of one yet.
But as I said earlier, I find no issues with the sound, but I will do as you suggested and try to learn more about hearing issues, thanks for bringing that up as it can only help me in the future.
I use the omnimic (with it's calibration file) at a distance of 16" on tweeter axis (learned from the method that toid uses) then take measurements from 1 metre away as well, to the sides and above the speaker, I then look at the spectral decay and also use DATS. I use the wharfdale to set the mic up, if I get a response that is the same as what others have tested I assume that if my speakers follow that and show a flat response that I'm pretty close, how good that method is I'm still unsure about but in my head it seemed ok. I still have a lot to learn with taking measurements though, but I have the basics down. I have struggled to find tutorials or books that go into every aspect of measuring, there is so much to it and very few places to learn it, i just don't have the time to trawl the internet for pieces of info and then try to put it all together, I'd rather pay for an in depth tutorial that teaches me the rest of what I need to know, I just don't know of one yet.
But as I said earlier, I find no issues with the sound, but I will do as you suggested and try to learn more about hearing issues, thanks for bringing that up as it can only help me in the future.
Yes it could very well be that he is used to different kind of sound and so thinks that mine is lacking somewhere, I don't know his history with speakers to know how good his ears are, it's just his comment made me question if I have been too bias because it's my own build. But a lot of other people have been impressed with them previously. The next project I I'm going to make a thread for it and upload everything I do, if at the end of that I haven't done something really wrong then I'll feel more confident in my abilities.
I like that idea, I suppose it's a bit limiting to what drivers you can use but yeah it saves a lot of work. They look pretty good too,
My mrs is constantly on at me about the amount of speakers that are building up in the house, because I don't try to sell them but still want to make them, so they just keep multiplying 😆 I can't help it though, I enjoy the process and the music.
The idea is to eliminate any resonances from the speaker box itself, not to enhance them. At least that's what most people try to do. And a metal enclosure at 2mm thick could very well have some ringing in the audio range. Damping material glued to the metal panels will help, but will it really get rid of all the ringing? I don't know, but why take the chance.
On the other hand, you may, in fact, like those other sounds, and if so, a metal enclosure could very well suit your purposes. I just think most people here would go in the opposite direction and not take the chance.
But you seem to be just as much concerned about appearance as sound quality, so you should do what gives you the most overall satisfaction.
Getting back to your original post, you built a speaker with an MDF and metal enclosure for someone else and he didn't like it although you did. I'm not sure you can rule out the metal as being the reason for his dislike of it. Perhaps it was something else, but the metal certainly needs to be looked at as the possible problem.
Finally, there are some people here, and I am one of them, who won't even use MDF for speaker enclosures. I use high quality Baltic Birch plywood exclusively. Nothing else. It's gotten fairly expensive now, but still worth the money in my opinion.
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2 cents worth >
A truly 'flat' speaker that uses high quality low distortion drivers can simply be made to sound 'exciting' or 'impressive' just using EQ.
However, small speakers can never have quite the bass impact of large ones without adding a Subwoofer.
AND sooo much comes down to ROOMS & REFLECTIONS + MTM speakers are very critical of 'speaker height'.
( I have reservations regarding the mentioned amp being used )
A truly 'flat' speaker that uses high quality low distortion drivers can simply be made to sound 'exciting' or 'impressive' just using EQ.
However, small speakers can never have quite the bass impact of large ones without adding a Subwoofer.
AND sooo much comes down to ROOMS & REFLECTIONS + MTM speakers are very critical of 'speaker height'.
( I have reservations regarding the mentioned amp being used )
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I'm not sure what the current state of Dayton microphone calibration files is, but last time I did some testing the manufacturer provided calibration were worthless - no basis in reality. These mics are typically hot by a few db or more in the treble, which means your treble could be down quite a bit. I recommend replacing the mic with another Dayton mic calibrated by CSL. I have personally verified CSL calibration agrees with the calibration from Earthworks and NTI mics as well as a DIY microphone I built 20 years ago that was calibrated by Kim Girardin.
I can't find TOID's measurements tutorial, but I did find a video of him recommending the Dayton mics for measurement - so you know what I think of that. Again, nothing wrong with Dayton mics but they need to be calibrated by a 3rd party.
Measuring inside is problematic because you need to splice the near field bass measurement, and the measurements are smoothed at lower frequencies. So you really have no idea what's going on with the bass, and resonances can be masked at lower frequencies. Jack Hidley of NHT said he considers this type of measurement worthless.
Its best to go outside, put your speaker as high in the air as possible and take some measurements that way. Do one measurement that is an average of a few on axis measurements (eg -20, -10, 0, 10 20 horizontal and +-10 vertical. Do a second measurement that is a 360 degree loop with measurements every 10-20 degrees to get a rough idea of the power response. The on axis should be flat and the power should be flat descending.
Can you share the drive units, crossover frequency/topology and any measurements you might have? This might be helpful.
Also, again, nothing wrong with a metal-mdf sandwich. If the adhesive you used has damping properties you can claim it's constrained layer construction! But I don't think the cabinet is your problem.
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Mic calibration is less important than people make out. Voicing is done by ear so you'll get it right.. The important measurements are significantly relative so the calibration doesn't count so much there.
On the other hand, USB mics are difficult to use for crossover work.
On the other hand, USB mics are difficult to use for crossover work.
The Universal Serial Bus was not designed for real-time communications. We are interested in the timing of our measurements down to fractions of a millisecond. There is a workaround for this where you attach an extra speaker to your microphone to pass special timing signals.
From the author of Vituixcad.
From the author of Vituixcad.
I didn't read whole thread carefully, but it seems no one suggested the most important thing - what is the in-room frequency response, measured at the listening position? If the room-induced null of the frequency response falls in the 60 - 100 Hz range, of course there will be no punch. Try several different loudspeaker position and/or listening position and measure each frequency response (no gating, 1/12 and 1/6 dB/octave smoothing).
It is very likely that the 'sound' your friend prefers could be obtained with EQ to suit his taste without resorting to degrading your too-good-for-him creation! LF requires a stiff enclosure; MF requires damping. When the same driver is doing both (something I would never design!) then the enclosure characteristics become tricky - it's fairly trivial to made an LF enclosure with resonances outside the pass band, but impossible further up the audio spectrum, where resonant peaks can be very high Q, even though they are of lower energy. Stiff and light materials such as sandwich panels seem to have been largely overlooked in speaker enclosures and on paper, at least, offer advantages. Perhaps worth a try on your new, smaller model.
Further, you would do well to Google the old BBC papers on cabinet design, as things can sometimes be somewhat counter-intuitive!
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subjective opinion for boring.
Likely is detailed and clear compared to a Bose.
You mentioned it is mono.
So mono is what it is.
Usually " boring" since stereo has more potential since the 1930's
more popular or recognized since the 1960's
I haven't heard your speaker.
But know the difference between mono and stereo.
Other than that, a good mid and tweeter does well regardless
for detail. More bass seems to make more instant impressions
with people.
Other than that depending on listening position.
MTM usually pretty poor vertical response.
Then again many systems have that issue and in real
life not really noticed.
people stream direct to blue tooth all the time now.
So at lower listening levels the bass could use a little bump up.
At louder volumes can come down usually.
More often done in the old days cause a normal amplifier
had bass and treble things and adjusted more easy.
If it is a itsy bitsy class D amp driving 4 ohm load.
hmmmm maybe it kinda sucks, who knows.
Im still thinking its more the mono thing
and just a basic bump of bass EQ needed.
Pretty normal for many speakers
Likely is detailed and clear compared to a Bose.
You mentioned it is mono.
So mono is what it is.
Usually " boring" since stereo has more potential since the 1930's
more popular or recognized since the 1960's
I haven't heard your speaker.
But know the difference between mono and stereo.
Other than that, a good mid and tweeter does well regardless
for detail. More bass seems to make more instant impressions
with people.
Other than that depending on listening position.
MTM usually pretty poor vertical response.
Then again many systems have that issue and in real
life not really noticed.
people stream direct to blue tooth all the time now.
So at lower listening levels the bass could use a little bump up.
At louder volumes can come down usually.
More often done in the old days cause a normal amplifier
had bass and treble things and adjusted more easy.
If it is a itsy bitsy class D amp driving 4 ohm load.
hmmmm maybe it kinda sucks, who knows.
Im still thinking its more the mono thing
and just a basic bump of bass EQ needed.
Pretty normal for many speakers
I feel I need to post the link to this amplifier, believe me, if I had ANY other option I would use that instead, but this is literally the only amp board I can find, it's a simple swap out if I can obtain a similar but better quality amp. But finding a high quality mono amp has been a real challenge, what do other people use when they design a bluetooth speaker? I'm even willing to buy an off the shelf bluetooth good quality speaker just to steal the internal amp if someone has any suggestions?
I'll try to reply to comments later today, I'm not ignoring anyone's input
https://www.amazon.co.uk/Waiecnksa-...luetooth+mono+amplifier+board,aps,144&sr=8-17
I'll try to reply to comments later today, I'm not ignoring anyone's input
https://www.amazon.co.uk/Waiecnksa-...luetooth+mono+amplifier+board,aps,144&sr=8-17
@Dameo182 Please look up loudness curve and also human hearing range and perception compared to volume. You will notice that a flat response speaker sounds as if it has little bass or treble to humans at lower volumes. This effect tapers off as volume increases. Around these parts we compensate this human condition with the classic smiley face eq curve. Because this effect tapers off you would not want to build this into the crossover unless you know at what level the speakers will be driven all the time.(as well as room response and other things) I guess I'm saying that flat sounds dull but it is the best place to start when you have to do the inevitable room and listening level corrections.
Oh and also I am not an expert so now you have 4cents (if the 2cents worth are in series)
Jeremy
There appear to be plenty of better quality stereo boards available. So just use one of those and ignore the second channel.
And here is a mono board that also could be a good candidate:
https://www.amazon.com/Bluetooth-Compatible-Amplifier-PEMENOL-Matching-Electronic/dp/B0BYJNYDGD
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I've recently made two pairs of stand mount speakers, one pair using 165mm paper bass drivers, crossing over to full range paper drivers at 200 (aprox) Hz, the other "Z" pair use 165mm woven glass fibre bass/mid drivers, with fill in bullet tweeters coming in around 8,000 Hz; I've been using the Z speakers quite a lot, partly to loosen up the drivers, partly to get the tweeter integrated (I'm not sure it's 100% there yet), I went back to the other speakers, and although the Z's sounded detailed, they sounded dead and boring in comparison to the others.
I attribute this to the light, stiff paper cones, the other extreme is polypropylene cones, that seem to suck all life out of music.
It's possible that if someone is used to Bose etc, that they're used to full range paper drivers, possibly augmented by a sub, resulting in a lively sound.
It's possible that your friend has given you the best, independent review of your speakers, that will help you find improvements that you would have otherwise overlooked, it's also just as possible that he has a totally different taste in sound, and given you a red herring.
I think copper should be a practical material for "dead" enclosures, that can result in a more vivid sound.
I attribute this to the light, stiff paper cones, the other extreme is polypropylene cones, that seem to suck all life out of music.
It's possible that if someone is used to Bose etc, that they're used to full range paper drivers, possibly augmented by a sub, resulting in a lively sound.
It's possible that your friend has given you the best, independent review of your speakers, that will help you find improvements that you would have otherwise overlooked, it's also just as possible that he has a totally different taste in sound, and given you a red herring.
I think copper should be a practical material for "dead" enclosures, that can result in a more vivid sound.
I see what you're saying about the metal maybe creating ringing in the audio range, I personally haven't heard anything strange from past builds, but I'll admit I'm not a professional listener, just someone who loves music and has listened for hours everyday all my life. But I was under the impression that doing measurements of the spectral decay would show up any problems in that area?
I do plan to make some cabinets out of birch ply at some point, I've never used it before and I always wanted to make a cabinet matching one of my already built MDF ones and doing a listening test between the two, I may even go one further and make multiple cabinets out of different materials and spending a day listening to see the differences. I need to make the time for that size of a project though.