Hi all!
Im very active on audio karma but im also trying to become active on this form as It seems pretty nice! Ive been browsing a lot on here and now its time for my first post.
Im a broke college student who loves audio engineering and I made my first real nice pair of speakers
Here are the specs
FaitalPRO 8fe200 8" woofer. 95db sensitivity
Morel CAT-308 1-1/8" soft dome tweeter in a wood horn. (90 db efficiency but the horn brings it to 96-97db
Crossover is 2.3 Khz 12db slope
Two Dayton audio KABD-4100 4x100w bluetooth amplifier with DSP. One 4 channel amp is for the speakers and the other will be for the subwoofer I'm making.
Ive done a lot of upgrades that have significantly improved the sound quality such as..
1. removing the faceplate from the tweeter so the dome sits closer to the throat of the horn (more ideal)
2. adding front baffles with a radius along the edges which improved the imaging
3. upgrading the wiring harness from the stock "aluminum wire" harness to a copper wire harness. this yielded a huge improvement in sound quality. A much fuller, signifigantly less harsh, more detailed sound and there is more "space between the instruments"
4. Using analog crossovers instead of the dsp. Initially there was. TON of hiss and noise coming from both the woofer and the tweeter due to the digital dsp not being able to filter out any hiss/noise after the DSP stage. This also made them sound noticeably less harsh and took the sound to the next level.
Over all this is a very large bookshelf speaker. The woofer sits in a 1.2 cu ft ported enclosure and I has usable response down to 60-ish hz but I am working on a subwoofer design with a Ciare HS251 10" DVC subwoofer and should have that done in two months or so. so far I've spent $2000 on these speakers (including $700 on super nice 13 layer baltic birch ply for the subwoofer and main speakers)
here is a picture of the speakers
One of the woofers was punctured with a falling clamp so I used silicone adhesive to seal it back up and it does the job but ill be buying another woofer soon .
each speaker weighs approximately 25-30 lbs. very heavy and there is a lot of bracing and sound deadening in each one. The front baffle is removable and the final design will have nice threaded Allen bolts that sit flush with the front baffle for easy removal and better looks.
But how do they sound???
When I made the first prototypes (before all the improvements listed above) they sounded lively, dynamic, but very harsh and saturated, and they seemed to lack detail and fullness and there was a ton of noise and hiss. after doing all of these improvements, they have fantastic imaging, SUPER clear sound, more "space between the instruments", a much fuller sound, and less hiss. if I had to describe the sound, I would say it is very "luscious" and you don't "hear" the boxes/enclosures nearly as much as when I first made the prototypes. they do lack some Low end authority below 50hz, but soon I will add a meaty subwoofer that should be able to hit 35hz at 113db at peak output. The analog crossover and copper wiring harness both made the most significant improvements to the sound and really took it to the next level.
Eventually I will be 3d printing the horns as the wooden ones don't fit perfectly and are slightly sloppy as they needed a two sided cnc machining procedure which is very hard to do but for now they do the job.
I will also be making a nice wood enclosure for both amplifiers and power supplies that matches the speakers but this is after I complete the subwoofer.
I am already super happy with the sound and they definitely "hi-fi". very very good sound! I cannot wait until the subwoofer is done!
MY ONLY GRIPE is there is some mild distortion in the midrange from the tweeter. im not sure if this is my room (listening in a 20x20 room so im sure there are room nodes) but ill take some measurements of the speakers outside and post them later.
I may try and make better horns but I need help selecting and designing horns so any advice is appreciated!
Im very active on audio karma but im also trying to become active on this form as It seems pretty nice! Ive been browsing a lot on here and now its time for my first post.
Im a broke college student who loves audio engineering and I made my first real nice pair of speakers
Here are the specs
FaitalPRO 8fe200 8" woofer. 95db sensitivity
Morel CAT-308 1-1/8" soft dome tweeter in a wood horn. (90 db efficiency but the horn brings it to 96-97db
Crossover is 2.3 Khz 12db slope
Two Dayton audio KABD-4100 4x100w bluetooth amplifier with DSP. One 4 channel amp is for the speakers and the other will be for the subwoofer I'm making.
Ive done a lot of upgrades that have significantly improved the sound quality such as..
1. removing the faceplate from the tweeter so the dome sits closer to the throat of the horn (more ideal)
2. adding front baffles with a radius along the edges which improved the imaging
3. upgrading the wiring harness from the stock "aluminum wire" harness to a copper wire harness. this yielded a huge improvement in sound quality. A much fuller, signifigantly less harsh, more detailed sound and there is more "space between the instruments"
4. Using analog crossovers instead of the dsp. Initially there was. TON of hiss and noise coming from both the woofer and the tweeter due to the digital dsp not being able to filter out any hiss/noise after the DSP stage. This also made them sound noticeably less harsh and took the sound to the next level.
Over all this is a very large bookshelf speaker. The woofer sits in a 1.2 cu ft ported enclosure and I has usable response down to 60-ish hz but I am working on a subwoofer design with a Ciare HS251 10" DVC subwoofer and should have that done in two months or so. so far I've spent $2000 on these speakers (including $700 on super nice 13 layer baltic birch ply for the subwoofer and main speakers)
here is a picture of the speakers
One of the woofers was punctured with a falling clamp so I used silicone adhesive to seal it back up and it does the job but ill be buying another woofer soon .
each speaker weighs approximately 25-30 lbs. very heavy and there is a lot of bracing and sound deadening in each one. The front baffle is removable and the final design will have nice threaded Allen bolts that sit flush with the front baffle for easy removal and better looks.
But how do they sound???
When I made the first prototypes (before all the improvements listed above) they sounded lively, dynamic, but very harsh and saturated, and they seemed to lack detail and fullness and there was a ton of noise and hiss. after doing all of these improvements, they have fantastic imaging, SUPER clear sound, more "space between the instruments", a much fuller sound, and less hiss. if I had to describe the sound, I would say it is very "luscious" and you don't "hear" the boxes/enclosures nearly as much as when I first made the prototypes. they do lack some Low end authority below 50hz, but soon I will add a meaty subwoofer that should be able to hit 35hz at 113db at peak output. The analog crossover and copper wiring harness both made the most significant improvements to the sound and really took it to the next level.
Eventually I will be 3d printing the horns as the wooden ones don't fit perfectly and are slightly sloppy as they needed a two sided cnc machining procedure which is very hard to do but for now they do the job.
I will also be making a nice wood enclosure for both amplifiers and power supplies that matches the speakers but this is after I complete the subwoofer.
I am already super happy with the sound and they definitely "hi-fi". very very good sound! I cannot wait until the subwoofer is done!
MY ONLY GRIPE is there is some mild distortion in the midrange from the tweeter. im not sure if this is my room (listening in a 20x20 room so im sure there are room nodes) but ill take some measurements of the speakers outside and post them later.
I may try and make better horns but I need help selecting and designing horns so any advice is appreciated!
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Looks like a cool project, nicely done.
I would recommend keeping the active filtering but ditch the DSP (go analogue) and increase the slope to ~48db/oct.
I am a little puzzled how you hear a difference between copper and aluminium but there you go...
I would recommend keeping the active filtering but ditch the DSP (go analogue) and increase the slope to ~48db/oct.
I am a little puzzled how you hear a difference between copper and aluminium but there you go...
Well I do lots of experimenting and have pretty good ears. We’re talking 20 awg aluminum vs 18 guage copper. The difference wasn’t small, it was VERY VERY VERY apparent. Much fuller sound, less harsh, more detail. Took the sound from an 7 /10 to a 9/10
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I’ll mention too I’m using a combination of active and analog filters. The indicators I have don’t crossover low enough and the capacitors I have don’t crossover over high enough so I use a little of both to get the sound I want. I just adjusted it based off of what my ears liked.
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Looks great!
I'm always a little confused about how going "backwards" to old-school passive filters could make things sound better, but it could be a few things. I'm a big fan of current amplifiers and high output resistance as a technique to potentially reducing distortion, and passive XOs usually help the tweeters in this regard almost by "accident".
Try putting say 22 ohms in series with the tweeter, and compare the result with a direct connection (with a cap for protection) and the gain turned down. Unless the amplifier is already very special, series resistor could really clean it up. Not to mention reduce noise. That's the other thing -- you've boosted the sensitivity with the waveguide. Somewhere, between the 2 extremes of infinite damping factor and 0 damping factor, there could be a sweet spot that minimises horn resonances.
I'm always a little confused about how going "backwards" to old-school passive filters could make things sound better, but it could be a few things. I'm a big fan of current amplifiers and high output resistance as a technique to potentially reducing distortion, and passive XOs usually help the tweeters in this regard almost by "accident".
Try putting say 22 ohms in series with the tweeter, and compare the result with a direct connection (with a cap for protection) and the gain turned down. Unless the amplifier is already very special, series resistor could really clean it up. Not to mention reduce noise. That's the other thing -- you've boosted the sensitivity with the waveguide. Somewhere, between the 2 extremes of infinite damping factor and 0 damping factor, there could be a sweet spot that minimises horn resonances.
Your current horns don't look too bad, but may not be a match the way you've done them. Could you give some information about them?
They are all capable of sounding about the same. Many accounts will draw conclusions in cases where something prevented the best performance being realised.
@abstract
They are Joseph Crowe biradial horns, number “1323” . They play down to 1200hz I believe. I get response down to 800 measured on my mic but I cross it over at ~2.2khz. 12db slope
At one point I did a zobel filter network (on the woofer) and got measurably better (flatter) phase response from 1k to 5k and this resulted in noticeably better blending of the drivers. The midrange imaging was tighter and more focused HOWEVER this reduces the dynamics of the woofer and the speaker wouldn’t really “open up” unless I played them louder. My audio mentor explain to me that Zobel filters, while in theory, measure better don’t necessarily sound better and that they usually give a “unnatural timbre” to the sound and I would agree. It has its plus and minuses.
As far as dampening factor I haven’t really read up on that but I have a small idea how it works. I’ll maybe order some resistors and play around with the idea.
my audio mentor also recommended I add a small phase plug in the throat of the horn which might help since the horn is only effective to ~14khz and boosting the highs with DSP sounds just ok but slightly more ear piercing.
As they stand the sound is almost 90% where I want it to be. I think the meat of a big subwoofer (1.9 cu ft box/10” woofer) should even the sound out
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They wouldn't be usable there, too small... but maybe 2k2Hz is OK. I'd measure to be sure.
I disagree. If you hear a difference it's the response change you're hearing, not the circuit itself.. and if you're hearing a difference but not expecting one, then you're not checking your response properly before drawing conclusions.
Sounds excessive. Is there any good reasoning behind it or is it just a guess?
There’s reasons to do it. My audio mentor has a masters in physics and he engineered a new modern multicell horn and does lots of engineering for lots of large companies and celebrity clientele including Louis Vuitton and I’m not joking when I say this, he is probably one of the top 10 audio engineers in the world. He is just insanely good and knowledgeable about horn design. From half million dollar club systems to new horn designs on the cutting edge of horn engineering, he does it all. And he’s been doing it for a long time.
I can’t speak much more about a lot of the crazy stuff he’s doing right now but me and him talked about my horn design and he said it would be worth trying a phase plug. I believe it has to do with reducing the radiating area that the tweeter has to radiate into as well as not allowing some kind of reflections to form and cancel in the throat at higher frequencies. Don’t quote me on that exactly as I am a novice and this conversation we had was two months ago.
As far as the sound quality with a zobel network, One thing that my Audio mentor told me was that in theory many things will measure and perform better but won’t sound right in practice. There’s far more to a speaker than just frequency response. Yes it measures better in some areas but it definitely sounds a little bit strange and less life like with a zobel. Of course that’s just for my specific offer in my specific application it might work in other applications.
Yes, polars may reveal information on your cross.
Perhaps if it were analysed as a waveguide and not a horn?
Yes they are! I love using them with my RH 84 amp. I have a CNC machine in my closet so that’s how I make everything
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www.current-drive.info is a good resource. Motor strength is N/A or newtons / amp, so it's the current that determines the signal strength. The voice coil is surrounded by an air-gapped magnetic core, which also has conductive parts. So its impedance keeps changing depending on things like signal strength and geometric position. Putting a resistor in series reduces the amount of modulation that is possible (an ideal current source with infinite V across infinite R will stabilise the current pushed through the system).
But then the physical nature of the speaker changes as well, at the upper extreme Qms = Qts (someone correct me if I'm being inaccurate). So the mechanical impedance peaks will tend to produce bigger frequency response peaks.
Break-up modes could also be different, since the amplifier no longer attempts to electrically brake the VC in response to spurious voltages.
So there's a lot of stuff going on!
(Ran out of edit time..)
A possible caveat, which could be the reason, or one of the reasons, why voltage amplifiers became a thing: current amplifiers would be more likely to blow up speakers. For a given level of gain, if the voice coil starts to get hot, for a voltage amplifier that's no problem. It's just extra resistance in series, reducing the gain a little. But a current amplifier would automatically compensate for that thermal modulation and increase the gain. So that's one possible downside that I would watch out for.
Box design could also be different when going down that path. Not least because of the different Q tuning, but also because of the cone's ability (or inability) to trap the sound inside the box. My old Accuton speakers in hardwood boxes always had a certain harshness to the box sound, which I attributed to the amplifier "fighting" the high box SPL pressing against the cone. The sound leakage wasn't bad, but the system would generate harmonics based around those box modes. OTOH, I think systems with lower damping factors would have more comb filtering in the frequency response. The reflected box sound would mingle with the direct sound, producing peaks and dips. To avoid that, one of the old schools of thought was to create huge boxes, so the reflected amplitude is lower.
A possible caveat, which could be the reason, or one of the reasons, why voltage amplifiers became a thing: current amplifiers would be more likely to blow up speakers. For a given level of gain, if the voice coil starts to get hot, for a voltage amplifier that's no problem. It's just extra resistance in series, reducing the gain a little. But a current amplifier would automatically compensate for that thermal modulation and increase the gain. So that's one possible downside that I would watch out for.
Box design could also be different when going down that path. Not least because of the different Q tuning, but also because of the cone's ability (or inability) to trap the sound inside the box. My old Accuton speakers in hardwood boxes always had a certain harshness to the box sound, which I attributed to the amplifier "fighting" the high box SPL pressing against the cone. The sound leakage wasn't bad, but the system would generate harmonics based around those box modes. OTOH, I think systems with lower damping factors would have more comb filtering in the frequency response. The reflected box sound would mingle with the direct sound, producing peaks and dips. To avoid that, one of the old schools of thought was to create huge boxes, so the reflected amplitude is lower.
\I did add a lot of sound deadening to the inside. The cabinets have pink fiberglass and sound deadening adhesive mats used for car audio sound deadening. I also have good bracing on every panel.
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Ok here are photos of the simulated performance in WinISD of the subwoofer I am producing. I will be starting CNC machining it tomorrow. Here are simulated group delay responses, excursion at 200w if power, spl at 200 watts, and the box design (minus the side panel so you can see into it).
There will be a internal front baffle that the subwoofer behind a beauty cover front baffle. It will be made of 1” thick MDF. The front baffle will have Allen head screws that screw into the MDF baffle with threaded inserts.
The rest of the enclosure will be made of super nice 0.7” 13 layer Baltic birch ply. I will add some generic dynamat sound deadening and some fiberglass insulation. It is a 1.9 cu ft ported enclosure
There will be a internal front baffle that the subwoofer behind a beauty cover front baffle. It will be made of 1” thick MDF. The front baffle will have Allen head screws that screw into the MDF baffle with threaded inserts.
The rest of the enclosure will be made of super nice 0.7” 13 layer Baltic birch ply. I will add some generic dynamat sound deadening and some fiberglass insulation. It is a 1.9 cu ft ported enclosure
yes, silver vs copper cable is very obvious
i only use copper
really love ur woodwork. Nice project!
Alright everyone! Im close to getting the subwoofer done. I have CNC machined all panels except the small baffle inside that creates the port. Im going to finish CNC machining everything today and do some sanding and test fitting. I ran out of wood to machine the nice looking front baffle/beauty cover but I do not need it to have a good sounding sub so I will do that in a month or two. This front baffle does add length to the port but not having it will reduce the port length by 0.7” slightly shifting the tuning frequency up by a few Hz. I tried to post a video of my CNC cutting the internal brace but it was “too large for the server to process” 😬
Ok here is the subwoofer Minus the beauty cover sitting on a 1” thick MDF baffle. So far it Sounds Great. Super Hard Hitting, clean, and low bass. I do have to do some sanding on the enclosure too.
I also CNC machined a base plate for my amplifier chassis (made from 0.5” birch ply) for the dual KABD 4100 Amps and their two power supplies. I will be making a back amplifier chassis baffle to mount and wire up the Terminal Cups next which will tidy up the wiring, and I will have a 3 Prong AC Power Plug with a switch and fuse.
