http://members.optusnet.com.au/lpkevin1/untitled.GIF
this is the smoothest response I can get with acceptable bass extension. If I were to make it flat the F3 would only be 53Hz, which isnt acceptable for me and plus the box would be so small.
Theres a shallow dip of 1Db around the 60-100Hz region. The response slowly climbs up as it appraoches the midrange frequencies. The midrange would be slightly louder (1Db) than the bass around 60-100. Is this acceptable?
this is the smoothest response I can get with acceptable bass extension. If I were to make it flat the F3 would only be 53Hz, which isnt acceptable for me and plus the box would be so small.
Theres a shallow dip of 1Db around the 60-100Hz region. The response slowly climbs up as it appraoches the midrange frequencies. The midrange would be slightly louder (1Db) than the bass around 60-100. Is this acceptable?
freq resp
Well, I assume it does not take into account the room? At any rate, I would not worry about the +/- 1dB difference, the difference between two drivers of the same type will be much larger anyway. Also, the Fc difference between 45 or 53 Hz will not be audible unless you have a room that is very large and has no LF standing waves. If you like this speaker, built it and enjoy it, the bass will be OK. You may need to equalize it around the box response peak (is this closed box or basreflex?) depending on your room. Depending on room size you will get standing waves which may reinforce the speakers' hump. You should be able to hear that. Then you may need to equalise that out, or find a speaker position that limits it.
But i am no speaker expert, where are those experts??
Jan Didden
Well, I assume it does not take into account the room? At any rate, I would not worry about the +/- 1dB difference, the difference between two drivers of the same type will be much larger anyway. Also, the Fc difference between 45 or 53 Hz will not be audible unless you have a room that is very large and has no LF standing waves. If you like this speaker, built it and enjoy it, the bass will be OK. You may need to equalize it around the box response peak (is this closed box or basreflex?) depending on your room. Depending on room size you will get standing waves which may reinforce the speakers' hump. You should be able to hear that. Then you may need to equalise that out, or find a speaker position that limits it.
But i am no speaker expert, where are those experts??
Jan Didden
Jan's right, the 1 dB or so will be lost in the noise, if your actual speaker ends up with a response like this.
The single most important thing to do to make the bass be what you want it to be is to verify the driver parameters experimentally and adjust the tuning accordingly. Simulations are wonderful, but limited by the quality of data put into them.
The single most important thing to do to make the bass be what you want it to be is to verify the driver parameters experimentally and adjust the tuning accordingly. Simulations are wonderful, but limited by the quality of data put into them.
Well I can't verify the T/s parameters. 
Im just a person who suddenly wants to customize/build a set of speakers for long term use.
I respect most audiophiles. But...(dont flame me) I laugh at people who spend $100 on a set of cables. I laugh at people who spend hours listening to speakers to test them, instead of enjoying music. Those people are too materialistic. They arent true audiophiles, they are rich materialistic perfectionists.
I just want to build one decent set of speakers powered by a second hand Harman Kardon amp, and listen to music through them until I have a full time job (probably 6 years later). I'll prolly use them until they become ancient antiques.
So I'll be using these speakers for a long time, thus they need to be at ;east decent. I dont have the sophisticated measuring equipment.
So the drop is negligable aye? Might as well go ahead with the design.
The Crossover is taken care of by another guy, once I know what I want (driver, box, tuning, etc).
Can any of you audiophiles give me any potential pitfalls(warnings) in speaker design? (I.e. I know that u dont make the box square)
Im just a person who suddenly wants to customize/build a set of speakers for long term use.
I respect most audiophiles. But...(dont flame me) I laugh at people who spend $100 on a set of cables. I laugh at people who spend hours listening to speakers to test them, instead of enjoying music. Those people are too materialistic. They arent true audiophiles, they are rich materialistic perfectionists.
I just want to build one decent set of speakers powered by a second hand Harman Kardon amp, and listen to music through them until I have a full time job (probably 6 years later). I'll prolly use them until they become ancient antiques.
So I'll be using these speakers for a long time, thus they need to be at ;east decent. I dont have the sophisticated measuring equipment.
So the drop is negligable aye? Might as well go ahead with the design.
The Crossover is taken care of by another guy, once I know what I want (driver, box, tuning, etc).
Can any of you audiophiles give me any potential pitfalls(warnings) in speaker design? (I.e. I know that u dont make the box square)
tech.knockout said:Well I can't verify the T/s parameters.
Im just a person who suddenly wants to customize/build a set of speakers for long term use.
I respect most audiophiles. But...(dont flame me) I laugh at people who spend $100 on a set of cables. I laugh at people who spend hours listening to speakers to test them, instead of enjoying music. Those people are too materialistic. They arent true audiophiles, they are rich materialistic perfectionists.
I just want to build one decent set of speakers powered by a second hand Harman Kardon amp, and listen to music through them until I have a full time job (probably 6 years later). I'll prolly use them until they become ancient antiques.
So I'll be using these speakers for a long time, thus they need to be at ;east decent. I dont have the sophisticated measuring equipment.
So the drop is negligable aye? Might as well go ahead with the design.
The Crossover is taken care of by another guy, once I know what I want (driver, box, tuning, etc).
Can any of you audiophiles give me any potential pitfalls(warnings) in speaker design? (I.e. I know that u dont make the box square)
Well, I don't want to flame either, but you are worrying about a 1dB deviation, so that puts you squarely in the box with the rest of those fanatics that pay 100 $ (only 100 $? that's cheap! where have you been?) for cables.....
(Damn! I SAID I wouldn't flame...)
Jan Didden
IF you worry about minor things like +/- 1 dB as the others have said previously , is no big deal, BTW those peerless drivers are nice I have used the 5.25 in ones on mtm design combined with the vifa 1 in alu dome tweeter through my fave series x/over a 6.8 uF CAP ACROSS THE TWEETER AND A 0.45MH CHOKE ACROSS THE WOOFER TERMINALS WITH A 3.3/ 4.7 ohm resistor to blend the tweeter in so there you have it no use worrying about minor things if you do you will never build anything or have fun and if you do build it you will most likely still be listening to them when you are an old grey haired man with a long grey beard like me
Tech:
No need to snap. The software to test T/S parameters is free, though a little time consuming to learn, (Speaker Workshop). I think the only other thing you would need would be a cheap multimeter which, if you don't already have one, will probably do you good down the line. One of those, "I'm glad I bought it because it sure comes in handy for other things" type purchases.
If you don't want to measure the parameters, fine. Nobody's putting a gun to your head.
As a general rule, Peerless woofers tend to vary quite a bit from published specs, but when placed in a box, the variations all cancel out and you get response very similar to the published specs. So without measuring the parameters, you probably will do okay by going with the simulation using published specs.
Bob Brines' Peerless Pipe article shows one man's experience with Peerless woofers. I don't know what the specs were of the speakers he sent back, but the ones he kept will approximate the published specs when placed in a box. Bob is a member here.
http://geocities.com/rbrines1/
Unlike Bob, I never had to send Peerless woofers back, though.
This variation is what SY was trying to save you from. By the way, SY has argued vociferously against paying big money for cables in other threads.
No need to snap. The software to test T/S parameters is free, though a little time consuming to learn, (Speaker Workshop). I think the only other thing you would need would be a cheap multimeter which, if you don't already have one, will probably do you good down the line. One of those, "I'm glad I bought it because it sure comes in handy for other things" type purchases.
If you don't want to measure the parameters, fine. Nobody's putting a gun to your head.
As a general rule, Peerless woofers tend to vary quite a bit from published specs, but when placed in a box, the variations all cancel out and you get response very similar to the published specs. So without measuring the parameters, you probably will do okay by going with the simulation using published specs.
Bob Brines' Peerless Pipe article shows one man's experience with Peerless woofers. I don't know what the specs were of the speakers he sent back, but the ones he kept will approximate the published specs when placed in a box. Bob is a member here.
http://geocities.com/rbrines1/
Unlike Bob, I never had to send Peerless woofers back, though.
This variation is what SY was trying to save you from. By the way, SY has argued vociferously against paying big money for cables in other threads.
I always thought that testing/measuring parameters needed hardware. Yeh my father has a multimeter. Can you actually measure the parameters with just a multimeter?
I would if I can, but I can't.
There is alot of difference between tweaking (I.e. tweaking computers - I do that) and forking ridiculous amounts of hard earned cash for something so insignificant as cables. I'll end my arguement like this. There are already alot of threads about it.
I was given the impression that 1Db was alot, because 3 Db already requires a doubling of power.
Then build a kit. Seriously. You'll end up with a better speaker.
I've said it before and I'll say it again: trying to design and build a speaker without having the capability to measure frequency resonse and impedance is like trying to design and build a house without a ruler, hammer, or saws. Manufacturers' driver specs are usually works of fiction, and sometimes it balances out, sometimes it doesn't. Box losses are unpredictable and will affect your response considerably more than that 1 dB you're worrying about. And you'll be working absolutely and totally blind.
That $100 figure you bandy about won't even get you Audiophile-Approved banana plugs for your wires. Put another zero or two on the end if you want to buy actual cables. Not that you should; good old 12AWG will work just fine for normal-length runs; our local lumber shack sells it for about 40 cents a foot. If your amp wants to see higher capacitance or whatever, that's tweakable for about a buck or less- assuming you can measure!
You're correct about 3 dB representing a doubling of power, but that's a VERY different thing than a doubling of loudness. The ear/brain is logarithmic in response. 1 dB is pretty small, barely perceptible, and negligable compared to the 10 dB swings your room will cause.
L'esprit d'escalier:
Besides the obvious, the educational reason to go the kit route is that you have a proven, well-designed base. You start with that and can experiment with port changes, volume changes, whatever, but at least you've got a good reference and starting point. And you can always go back to it for listening to music.
This assumes a competent kit and a mature design. Beware of garage stuff.
Besides the obvious, the educational reason to go the kit route is that you have a proven, well-designed base. You start with that and can experiment with port changes, volume changes, whatever, but at least you've got a good reference and starting point. And you can always go back to it for listening to music.
This assumes a competent kit and a mature design. Beware of garage stuff.
no comment on the foregoing discourse only to say I am voluntarily exiling myself from posting on this forum untill august, before I GET SIN-BINNED AGAIN N not because of this thread but others that I HAVE SEEN OR DARED TO MAKE A COMMENT ON.... before I incur the wrath of the aal and mighty from above, I have suffered one stroke already and don't need anothe one just at the moment so I'M OFF TO SUNNY HUNGARY FOR 5 WKS TO clear my head ENJOY THE FINE WEATHER,WINE/ FOOD AND GOOD COMPANY and gypsy music, where the violins talk to you in the hands of the true masters of this instrument yehudi menhuin [ who?]notwithstanding... cheers to all and bye
topcat
Okay, I can give you a couple of links that will show you how to measure the parameters yourself.
A) Speaker Workshop. www.audua.com. this takes time to learn, but the big bonus is that you can measure your frequency response after you have made the speakers. This helps in designing a crossover, which can be complicated. I haven't learned it completely myself, but I will. You should consider this a $100 program that just happens to be freeware, and act accordingly. Also, here is a thread where these things are discussed.
http://www.diyaudio.com/forums/show...3&highlight=measuring+thiele+small+parameters
B) http://sound.westhost.com/tsp.htm If you have a sound card that has a high output jack, like a Sound Blaster, you can do away with the amp.
C) http://www.epanorama.net/documents/audio/speaker_parameters.html. Looks less complicated than B)
For a freeware online tone generator, go here:
http://duncan.rutgers.edu/physicsfreewares.htm
Just "blue over" the frequency written in the box and write in your own frequency. Then click "Start".
There is a fast way to check for Vas and Fs which I will give you tomorrow. You might not even need to check for Qts.
More tomorrow. Gotta run. I am going to check with a recent graduate of the University of Sydney to see if I can use his freeware program to give you a quick, easy way to measure Qts.
A) Speaker Workshop. www.audua.com. this takes time to learn, but the big bonus is that you can measure your frequency response after you have made the speakers. This helps in designing a crossover, which can be complicated. I haven't learned it completely myself, but I will. You should consider this a $100 program that just happens to be freeware, and act accordingly. Also, here is a thread where these things are discussed.
http://www.diyaudio.com/forums/show...3&highlight=measuring+thiele+small+parameters
B) http://sound.westhost.com/tsp.htm If you have a sound card that has a high output jack, like a Sound Blaster, you can do away with the amp.
C) http://www.epanorama.net/documents/audio/speaker_parameters.html. Looks less complicated than B)
For a freeware online tone generator, go here:
http://duncan.rutgers.edu/physicsfreewares.htm
Just "blue over" the frequency written in the box and write in your own frequency. Then click "Start".
There is a fast way to check for Vas and Fs which I will give you tomorrow. You might not even need to check for Qts.
More tomorrow. Gotta run. I am going to check with a recent graduate of the University of Sydney to see if I can use his freeware program to give you a quick, easy way to measure Qts.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.