Your speaker isn't even harmonic distortion controlled. A naked driver your enclosing yourself without test microphone & analyzer, right? You won't be using headphones if I read your posts correctly. Don't worry about induction in the resistors at 20 khz and below. The LM1875 is not incredibly low distortion anyway. That's why vendors push the LM3886 even if you don't need the watts. But you won't hear the 3rd or 4th digit difference of HD on speakers; people just obsess about it when buying amps.
My speakers have 2nd harmonic 20 db below 1 w signal 54-14000 hz, and 99.9999% of other speaker models won't specify it. If you get HD below 10% in the room with a home built speaker not copied from plans, I'd be surprised.
My speakers have 2nd harmonic 20 db below 1 w signal 54-14000 hz, and 99.9999% of other speaker models won't specify it. If you get HD below 10% in the room with a home built speaker not copied from plans, I'd be surprised.
Hi indianajo
So that's a really long way of saying no. But that is the journey of discovery. If you don't ask you never know. I'm in the process of setting up a mic & have a donated ocilloscope and frequency + square wave generator. Lastly what do you mean by "harmonic distortion controlled" Are you referring to a form motional feedback? I Intend as stated before to go active using this project for the tweeter & one of Tom's amps for the bass/mid. That may change in the future. But due to the necessity imposed by economics. That's the plan ATM.
Cheers
So that's a really long way of saying no. But that is the journey of discovery. If you don't ask you never know. I'm in the process of setting up a mic & have a donated ocilloscope and frequency + square wave generator. Lastly what do you mean by "harmonic distortion controlled" Are you referring to a form motional feedback? I Intend as stated before to go active using this project for the tweeter & one of Tom's amps for the bass/mid. That may change in the future. But due to the necessity imposed by economics. That's the plan ATM.
Cheers
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If you're getting into speaker design, getting a calibrated microphone is worth it. They're about $75-100 at Cross-Spectrum Labs.
HOLM Impulse is free measurement software for Windows.
FuzzMeasure is free (with limitations) or $99 for a hobbyist license the full version for Mac.
Tom
HOLM Impulse is free measurement software for Windows.
FuzzMeasure is free (with limitations) or $99 for a hobbyist license the full version for Mac.
Tom
By HD controlled I mean a manufacturer that publishes a HD spec on the datasheet samples their product often enough to prove that they meet it. In your case do you know what your speaker HD is? and have a plan to improve it? Sounds like you do, but it probably will be a long time and many tweaks before you get HD low enough for the LM1875 + parts to be a limitation. then there is high freq IM distortion. I'm a piano player & amateur tuner, who finds almost every speaker and room a failure when it comes to reproducing that instrument faithfully. I own & play two fine wood instruments.
BTW I mostly purchase metal film resistors which are inductive. Above 100k they have lower thermal hiss which can definitely be heard by contrast with the carbon comp resistors I replaced. At 22kohms which my LM1875 uses for a feedback resistor, either formula or even carbon film should be fine.
BTW I mostly purchase metal film resistors which are inductive. Above 100k they have lower thermal hiss which can definitely be heard by contrast with the carbon comp resistors I replaced. At 22kohms which my LM1875 uses for a feedback resistor, either formula or even carbon film should be fine.
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Hi Tom
Cool! Cheers for the heads up. I have actually been building & modifiying speakers for some time. One of my Tannoy Chevoits started out as a basket case. It now earns its keep in a mastering studio in Queensland. Edward who is the man behind Adelaide Speakers taught me everything I know. Has about 3500 builds under his belt and just about paid his house off through that buisiness. He tunes his entirely by ear & vast experience. But for me I need to explore a more precise and "pro-active" path to gain the goals I seek.
Cool! Cheers for the heads up. I have actually been building & modifiying speakers for some time. One of my Tannoy Chevoits started out as a basket case. It now earns its keep in a mastering studio in Queensland. Edward who is the man behind Adelaide Speakers taught me everything I know. Has about 3500 builds under his belt and just about paid his house off through that buisiness. He tunes his entirely by ear & vast experience. But for me I need to explore a more precise and "pro-active" path to gain the goals I seek.
@Indianajo
If you think piano is a fail for most speakers try harpsichord! That with hi res recordings is what I would use as a torture test. Yes I do agree most small 2 way speakers and full range drivers suck below 100 Hz distortion wise. And yes I play a B Pearl cantabile solid silver made in Japan and find that most recordings of popular flute suck. Good recordings are as rare as the speakers to enjoy them. To get my speakers right (my 3 way TL HDF 80 litre FOH) took 3 years @ the cross over.
Cheers Mark
If you think piano is a fail for most speakers try harpsichord! That with hi res recordings is what I would use as a torture test. Yes I do agree most small 2 way speakers and full range drivers suck below 100 Hz distortion wise. And yes I play a B Pearl cantabile solid silver made in Japan and find that most recordings of popular flute suck. Good recordings are as rare as the speakers to enjoy them. To get my speakers right (my 3 way TL HDF 80 litre FOH) took 3 years @ the cross over.
Cheers Mark
Cool, a speaker expert! I've heard some home built speakers that ****ed. And bad PA at local venues.
I've only heard a wood harpsichord close up once, 34 year ago, and that unit didn't have any A0-A1 bass strings. I've heard a lot of pianos, have a Sohmer 39 and Steinway 40 consoles in house, play a Howard 44" studio live weekly. Only Altec VOT and copies (my SP2) come close so far. Many famous speakers are bass deficient, never mind HD & IM. I never heard a magnaplaner, and the Klipschhorn in 1974 the dealer was playing light jazz, trumpet string bass snare, too easy to be worth the demo! My SP2 are good enough to make my "legendary" ST70 tube amp sound fuzzy, with 1% HD specified.
Too bad I can't travel to hear your successful units.
I've only heard a wood harpsichord close up once, 34 year ago, and that unit didn't have any A0-A1 bass strings. I've heard a lot of pianos, have a Sohmer 39 and Steinway 40 consoles in house, play a Howard 44" studio live weekly. Only Altec VOT and copies (my SP2) come close so far. Many famous speakers are bass deficient, never mind HD & IM. I never heard a magnaplaner, and the Klipschhorn in 1974 the dealer was playing light jazz, trumpet string bass snare, too easy to be worth the demo! My SP2 are good enough to make my "legendary" ST70 tube amp sound fuzzy, with 1% HD specified.
Too bad I can't travel to hear your successful units.
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I'm a fan of the Klipschorn. That corner loaded Bass is hard to beat. Especially the improvements in XO & mid & HF horns wrought by some aftermarket tuners in the states. Bass is still a work in progress with my FOH. 2 Peerless 12 pre XLR laid flat & upfiring on sub duties each in 135 litre sealed cabs. Need higher x max & better control via sub controller be that digital or analog. But it's a tough call fighting room nodes. Direct radiating corner loading shows some promise imho
Signing out as it is 3.20 AM here Cheers
Signing out as it is 3.20 AM here Cheers
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Room effects confound acoustic bands, too. Spring Branch Junior School auditorium, a wedge with brick walls and concrete floor, was awful. The Houston Astrodome, the acoustics were so bad they asked my high school band to play the dedication ceremony. We could follow the drum major's stick whatever the mess sounded like. Multiple echoes at various times over 1.5 second. My high school friend's Bose 901's driven by Heathkit AR15 in a heptagonal bedroom sounded blah. Good experience.
I've spent more on my music room (1.5 years pay) than my speakers amps analog sources - 2 weeks pay. It's a "shotgun" house, a paralellapiped with soft walls & floor - sort of like Wein Philharmonica hall with carpet & acoustic ceiling tile. Books sofas & organs on the walls. Speakers go high on the narrow end. Listening positions 12' away on axis in the LR and 30' away at the kitchen table. No frequency equalization required so far.
I've spent more on my music room (1.5 years pay) than my speakers amps analog sources - 2 weeks pay. It's a "shotgun" house, a paralellapiped with soft walls & floor - sort of like Wein Philharmonica hall with carpet & acoustic ceiling tile. Books sofas & organs on the walls. Speakers go high on the narrow end. Listening positions 12' away on axis in the LR and 30' away at the kitchen table. No frequency equalization required so far.
Cheers indianajo.
I am no expert but very stubborn and can't stand inferior sound. I realised that I NEED understanding. As compared to those out there who are driven by the need for sonic accuracy and musical exellence I am an amateur. But with speakers I believe I have been given a God given talent. Passive Cross overs are capable of excellent sound but those that achieve that benchmark are few and far between. It is MUCH easier to get there by going active. In the hi fi industry that is driven to maximise pofit it is simply not in their best interests so they are not that eager to change.
The pro music industry is also driven by the desire for profit BUT they have to cater to the demands of those out there who understand both the electronics and the need for musical accuracy. Namely recording engineers and professional musicians.
In the pro recording studios I have experience with here there is not one that uses a passive speaker as their main mixing monitor. Mastering studios do because the end listener will most likely be using the same.
I am no expert but very stubborn and can't stand inferior sound. I realised that I NEED understanding. As compared to those out there who are driven by the need for sonic accuracy and musical exellence I am an amateur. But with speakers I believe I have been given a God given talent. Passive Cross overs are capable of excellent sound but those that achieve that benchmark are few and far between. It is MUCH easier to get there by going active. In the hi fi industry that is driven to maximise pofit it is simply not in their best interests so they are not that eager to change.
The pro music industry is also driven by the desire for profit BUT they have to cater to the demands of those out there who understand both the electronics and the need for musical accuracy. Namely recording engineers and professional musicians.
In the pro recording studios I have experience with here there is not one that uses a passive speaker as their main mixing monitor. Mastering studios do because the end listener will most likely be using the same.
With you on live acoustics. Seems pi$$ poor untreated auditorium acoustics and retard live mixing "engineers" is a world wide epidemic.They shold be regulated &Licenced
The worst I remember was DJ Shadow. Won tickets on community radio. (Would have been one seriously angry ant if I'd paid) Invited a mate as I won 2 tickets.
Unreal visually the gig was DESTROYED by quite literally UNLISTENABLE mangled crap spewing forth from the speakers. We both left 20 minutes into the gig for the same reason and my mate is 40% deaf in his right ear! There are many others including Living Color( that I did pay for ) & Radio Birdman (think Iggy Pop really angry on a week long crack binge!) The best both visual and sound was Massive Attack in a notoriously difficult acoustic Adelaide Entertainment Centre.
The worst I remember was DJ Shadow. Won tickets on community radio. (Would have been one seriously angry ant if I'd paid) Invited a mate as I won 2 tickets.
Unreal visually the gig was DESTROYED by quite literally UNLISTENABLE mangled crap spewing forth from the speakers. We both left 20 minutes into the gig for the same reason and my mate is 40% deaf in his right ear! There are many others including Living Color( that I did pay for ) & Radio Birdman (think Iggy Pop really angry on a week long crack binge!) The best both visual and sound was Massive Attack in a notoriously difficult acoustic Adelaide Entertainment Centre.
Here is my LM1875 stereo amp.
I've learned how to edit the files down from 1.4 mb to .5 so diyaudio will accept them, but haven't figured out how to crop off the greyed out blocks.
There are top & bottom grates of the same material as the bulkhead in the middle, to keep out RF. There is a MOS supressor ahead of the tranformer to cut down lightning snaps, but the internal bulkhead should help. Parallel a .01 uf 500 v disk cap of course.
Board has three mounting options, installed, components up, and wiring up. Last two are for debug. First allows the covers to be put on. Spacers on #6 screws are 1/4" pneumatic tubing cut to length. Case is tapped for mount screws and an angle bracket is on the front for wiring up mount.
Case is salvage Bud chassis from 10 channel continuity leakage tester found in trash. Goal is to make something that hunters/fishers/kids wandering through my country camp trailer will not steal. I'm not there in the fall/winter/spring. So far they have only stolen a jon-boat, a coleman lantern, and a turkey cooking pot. But they leave the door standing open so birds **** on everything. If I lock the door they would probably would just break a window out. Which would take a $120 truck rental to haul out supplies to repair.
One speaker is a 1998 Peavey 15"+horn wedge monitor 8 ohms. Other is TBD. They haven't stolen the speaker. I want to listen to good music/radio while cutting up tree limbs and the 1 watt ? FM radio isn't loud enough.
I've learned how to edit the files down from 1.4 mb to .5 so diyaudio will accept them, but haven't figured out how to crop off the greyed out blocks.
There are top & bottom grates of the same material as the bulkhead in the middle, to keep out RF. There is a MOS supressor ahead of the tranformer to cut down lightning snaps, but the internal bulkhead should help. Parallel a .01 uf 500 v disk cap of course.
Board has three mounting options, installed, components up, and wiring up. Last two are for debug. First allows the covers to be put on. Spacers on #6 screws are 1/4" pneumatic tubing cut to length. Case is tapped for mount screws and an angle bracket is on the front for wiring up mount.
Case is salvage Bud chassis from 10 channel continuity leakage tester found in trash. Goal is to make something that hunters/fishers/kids wandering through my country camp trailer will not steal. I'm not there in the fall/winter/spring. So far they have only stolen a jon-boat, a coleman lantern, and a turkey cooking pot. But they leave the door standing open so birds **** on everything. If I lock the door they would probably would just break a window out. Which would take a $120 truck rental to haul out supplies to repair.
One speaker is a 1998 Peavey 15"+horn wedge monitor 8 ohms. Other is TBD. They haven't stolen the speaker. I want to listen to good music/radio while cutting up tree limbs and the 1 watt ? FM radio isn't loud enough.
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