My dad once phoned up asking if they had in stock a particular toroid traffo, toroidal she said?? is that some make.....
🙄 🙄 🙄
🙄 🙄 🙄
SimontY said:
The spec sheets of the AP100Z0 and TM025F1:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The impedance is 8 ohms...
By the look of the graph, it should be flat to about 1.5kHz.
Thanks for the advice, but i'll wait for a second opinion...
I like them 🙂 If bigparsnip cannot find out in the next couple of days if we can still get these, I can get my mate that works in the Sheffield city centre one to find out.
I only work there part time, so unless I go in tomorrow (it is only a five minute walk from where I live so it isn't too much trouble) it may take a while ofr me to find out, so you may want to get your friend to see if he can check too.
Cool, that's my local Maplins nowadays 🙂richie00boy said:
What's your mate's name and what does he look like? If you don't mind, curiosity...
5th Element:-
Are you able to define why you prefer a sealed enclosure over a ported one for me? in your reply, unless i have read it incorrectly ( a definite posibility) you only state a preference and not the reason why you like that preference.
Please humor me and explain further, I am asuming that a ported enclosure would sound slow and undefined with no punch???
I am also a little confused by some items in your explanation:-
MI think the bass loss in a sealed will be negligable or even apparent because it actually plays louder lower. [/]
you then go on to say:-
I am a big fan of sealed boxes anyway better bass quality. Usually for a small pair of speakers I would want to go ported to maximise bass output but in this case sealed, to me, would be fine.
Is Louder lower different to maximum bass output?
with a ported design is the bass output, centered around the tuned frequency of the port?
Would anyone be able to summaridise the different charactaristics of each design, the pro's and con's?
am i close or heading off on one?
still gives me something to think about over lunch 😉
m
Are you able to define why you prefer a sealed enclosure over a ported one for me? in your reply, unless i have read it incorrectly ( a definite posibility) you only state a preference and not the reason why you like that preference.
Please humor me and explain further, I am asuming that a ported enclosure would sound slow and undefined with no punch???
I am also a little confused by some items in your explanation:-
MI think the bass loss in a sealed will be negligable or even apparent because it actually plays louder lower. [/]
you then go on to say:-
I am a big fan of sealed boxes anyway better bass quality. Usually for a small pair of speakers I would want to go ported to maximise bass output but in this case sealed, to me, would be fine.
Is Louder lower different to maximum bass output?
with a ported design is the bass output, centered around the tuned frequency of the port?
Would anyone be able to summaridise the different charactaristics of each design, the pro's and con's?
am i close or heading off on one?
still gives me something to think about over lunch 😉
m
Hmmm, this is my understanding of it from reading threads like this and just thinking about it (though that could change soon as ive just ordered 4 of those 4" drivers too, hehe)
With a ported enclosure, the spl you get direct from the driver isn't far off what you get in a sealed enclosure, and goes down to a similar level too (around 100Hz in this case). However, if you add to this the spl from the port (assuming it is tuned correctly), this adds itself to the original spl from the driver itself. As you can tune the ports, this enables you to extend the bass response, but as the air has had to travel a different route to your ear than the air coming direct from the driver cone, there will be phase errors, which would reduce the definition and clarity of the bass, even though it would be louder. However, with a sealed enclosure, there is only one source for the sound to come from (assuming enclosure colouration is negligable, and that we ignore room reflections
), the driver cone itself, meaning that all sound is in phase (that originates from the speaker) resulting in tighter cleaner bass, but with not such a flat total spl response lower down.
The best solution I can come up with is to have two bass drives, one sealed and one ported. the sealed one going down to 100Hz, and the ported one only doing 100Hz and below, so it doesn't mess up the sound where the sealed enclosure can cope perfectly well.
PS Im not pretending any of this is fact! hehe, just my understanding at this point 🙂
Steve
With a ported enclosure, the spl you get direct from the driver isn't far off what you get in a sealed enclosure, and goes down to a similar level too (around 100Hz in this case). However, if you add to this the spl from the port (assuming it is tuned correctly), this adds itself to the original spl from the driver itself. As you can tune the ports, this enables you to extend the bass response, but as the air has had to travel a different route to your ear than the air coming direct from the driver cone, there will be phase errors, which would reduce the definition and clarity of the bass, even though it would be louder. However, with a sealed enclosure, there is only one source for the sound to come from (assuming enclosure colouration is negligable, and that we ignore room reflections
), the driver cone itself, meaning that all sound is in phase (that originates from the speaker) resulting in tighter cleaner bass, but with not such a flat total spl response lower down.The best solution I can come up with is to have two bass drives, one sealed and one ported. the sealed one going down to 100Hz, and the ported one only doing 100Hz and below, so it doesn't mess up the sound where the sealed enclosure can cope perfectly well.
PS Im not pretending any of this is fact! hehe, just my understanding at this point 🙂
Steve
"Are you able to define why you prefer a sealed enclosure over a ported one for me?"
His reason is probably that sealed gives less clue that you're hearing something that is artificial and not live. All ported speakers seem to laag when moving from one bass note to the next, causing a smearing of the bassline, a confusing mush. How bad this is depends on many factors. Particularly dependant on the music played - something fast and intricate with plenty of presence in the bass is tough.
"Please humor me and explain further, I am asuming that a ported enclosure would sound slow and undefined with no punch???"
Can sound slow and undefined, but defined is misleading - I believe the leading edge of the note comes out well through ported speakers, but that real bass doesn't always have a sharp leading edge. Ported bass is punchy, sealed is not, by the way most people describe 'punchy'. PA speakers in a club are a good example of all the pros and cons of ported speakers IMO. Of course, they're not always ported 😉
"I am also a little confused by some items in your explanation:-
I think the bass loss in a sealed will be negligable or even apparent because it actually plays louder lower."
The rolloff starts sooner in a sealed speaker, but is more gradual - 12db/octave rather than 18db/octave (I may have the numbers wrong) so when you get really low - the ported has no useful output but the sealed has some. Sealed bass would surely be no use in an anechoic room ie. no reinforcement from the room, but its rolloff may work better than ported in a real situation/room.
"Is Louder lower different to maximum bass output?"
Yeh generally, because most ported designs emphasise bass at the tuning frequency to make a slamming, thumping sound. And I believe it is group delay that makes this even more obvious, and lagged.
"am i close or heading off on one?"
I think you're close mostly, someone else will explain more and better than I can though. 🙂
edit: I agree with what Steve says too, our posts reflect the same things really
ps - It's hard to know the sealed sound well as most drivers have their parameters tailored for ported loading, and these days nearly all reasonably priced commercial speakers use ported loading. This is for the excitement in 10mins listening in a dealers dem room - I'm sure of this.
His reason is probably that sealed gives less clue that you're hearing something that is artificial and not live. All ported speakers seem to laag when moving from one bass note to the next, causing a smearing of the bassline, a confusing mush. How bad this is depends on many factors. Particularly dependant on the music played - something fast and intricate with plenty of presence in the bass is tough.
"Please humor me and explain further, I am asuming that a ported enclosure would sound slow and undefined with no punch???"
Can sound slow and undefined, but defined is misleading - I believe the leading edge of the note comes out well through ported speakers, but that real bass doesn't always have a sharp leading edge. Ported bass is punchy, sealed is not, by the way most people describe 'punchy'. PA speakers in a club are a good example of all the pros and cons of ported speakers IMO. Of course, they're not always ported 😉
"I am also a little confused by some items in your explanation:-
I think the bass loss in a sealed will be negligable or even apparent because it actually plays louder lower."
The rolloff starts sooner in a sealed speaker, but is more gradual - 12db/octave rather than 18db/octave (I may have the numbers wrong) so when you get really low - the ported has no useful output but the sealed has some. Sealed bass would surely be no use in an anechoic room ie. no reinforcement from the room, but its rolloff may work better than ported in a real situation/room.
"Is Louder lower different to maximum bass output?"
Yeh generally, because most ported designs emphasise bass at the tuning frequency to make a slamming, thumping sound. And I believe it is group delay that makes this even more obvious, and lagged.
"am i close or heading off on one?"
I think you're close mostly, someone else will explain more and better than I can though. 🙂
edit: I agree with what Steve says too, our posts reflect the same things really
ps - It's hard to know the sealed sound well as most drivers have their parameters tailored for ported loading, and these days nearly all reasonably priced commercial speakers use ported loading. This is for the excitement in 10mins listening in a dealers dem room - I'm sure of this.
Talk of ported enclosure being washy, lagging, smearing etc is rubbish IMO. If it's done corectly, a ported enclosure has other advantages in addition to extended response, such as less excursion near resonance which results in less distortion. Selaed vs ported is an aged argument, and neither is definitively better than other. I suggest reading up on the basics from the resevoir of sealed vs ported discussions that already exists. If it's your first design, then sealed it should be for simplicity IMO.
Simon you basically covered it all anyway.
Sealed matches with room gain better then ported, sealed has no farting port to consider. Sealed has better transient response so subsequently can "start and stop" faster, bass lines not smearing and all that. I'd much prefer to have high quality bass that may not go quite as low, then low bass thats not tuneful.
A ported enclosure however, if designed well, can sound really really good, if they were that bad manufactures wouldnt pick them all the time.
If you look at the impulse response for the sealed and ported boxes, there is not much in it. Both the sealed and ported have a very similar response, the sealed being marginally better.
However the group delay for a ported enclosure is significantly worse. The dealy doesnt go above 2.8ms in the sealed inclosure, but in the ported reaches 2.8 at 93hz and increases to 12.5ms at 36 hz. Im not 100% technically minded when it comes to these things because I have not studied them in depth but I do know that the sealed cab performs better on paper and in real life, most DIY'ers go for sealed bass if its to be high quality, if they can. Ofcourse if you really want maximum extension as per HT where quality is not the main concern, ported offers good advantages.
Sealed matches with room gain better then ported, sealed has no farting port to consider. Sealed has better transient response so subsequently can "start and stop" faster, bass lines not smearing and all that. I'd much prefer to have high quality bass that may not go quite as low, then low bass thats not tuneful.
A ported enclosure however, if designed well, can sound really really good, if they were that bad manufactures wouldnt pick them all the time.
If you look at the impulse response for the sealed and ported boxes, there is not much in it. Both the sealed and ported have a very similar response, the sealed being marginally better.
However the group delay for a ported enclosure is significantly worse. The dealy doesnt go above 2.8ms in the sealed inclosure, but in the ported reaches 2.8 at 93hz and increases to 12.5ms at 36 hz. Im not 100% technically minded when it comes to these things because I have not studied them in depth but I do know that the sealed cab performs better on paper and in real life, most DIY'ers go for sealed bass if its to be high quality, if they can. Ofcourse if you really want maximum extension as per HT where quality is not the main concern, ported offers good advantages.
Thought that would catch your eye 😉 He's only been there a couple of months. Tallish guy with light colour hair.
Is there an alternative to the TM025F1? Only, they are a *few* dotted around the country, but that seems to be it. They have been on order since 2002 in the city shop according to my mate, so looks unlikely that the 28 days replenishment will appear on the website.
One more thing to add to the sealed vs. ported debate. Any smearing - or more accurately poor transient response - occurs only around resonance. Thus having a driver in a sealed box for only down to 100Hz, crossing over to another identical driver doing the rest below in a ported enclosure, is largely a waste of time - the bass around 90-200Hz (assuming 60Hz tuning) will be largely unaffected by the port.
richie00boy said:
Yeh I see that now. Seeing as these drivers are only a fiver each I think Ill still give it a go though for experimentations sake
Steve
If you have a large driver that only needs a very low tuning frequency anyway ina box then the additional onset of group delay is not as big a deal because the increase occurs really low in frequency for it not to be a problem.
Yes it is true that excursion is lower AT resonance but in a ported encloser after this the excurcion increases dramatically.
With the current audax driver in question, ported excusion increases to a peak at 76hz at 3mm p-p with 1 watt into 8ohms, note this is a 6ohm driver. Then decreases again to 1mm at 55hz(resonance or port), but has increased back to 3mm by 48hz and then increases to 6mm by 38hz.
Whereas the sealed varient doesnt go above 3.5mm even at 5hz.
100hz= 2.3mm
76hz = 2.875mm
55hz = 3.276mm
40hz = 3.331mm
Yes it is true that excursion is lower AT resonance but in a ported encloser after this the excurcion increases dramatically.
With the current audax driver in question, ported excusion increases to a peak at 76hz at 3mm p-p with 1 watt into 8ohms, note this is a 6ohm driver. Then decreases again to 1mm at 55hz(resonance or port), but has increased back to 3mm by 48hz and then increases to 6mm by 38hz.
Whereas the sealed varient doesnt go above 3.5mm even at 5hz.
100hz= 2.3mm
76hz = 2.875mm
55hz = 3.276mm
40hz = 3.331mm
wow guys thanks, i am away for a few minutes and look what happens - i understand a little more now great
Most importantly I will be going for a sealed enclosure, i must leave soon to go and get those hens teeth tweeters 😀
m
Most importantly I will be going for a sealed enclosure, i must leave soon to go and get those hens teeth tweeters 😀
m
Hi chaps :
Just some thoughts on said drivers :
a) without a subwoofer ported is the way to go, with
a subwoofer sealed in fine, also sealed is fine for very
compact speakers.
b) the tiny Vas (hence highish Fs) makes large box
alignments pretty pointless as Vas dominates.
c) tuning to 45Hz is about as low as you can go for minimum F6.
d) for 2 drivers a 2 way MTM with BSC or 2.5 way can be used -
4 ohm in the bass - ~ 85dB/2.83V.
d) for 3 drivers per speaker a 3 way is best, 2 for bass reflexed,
one sealed for midrange - 4 ohm in the bass ~ 85dB/2.83V.
e) for 4 drivers they need to be used in series pairs, a
2.5 way, both MTMMM and TMMMM are possible.
A sealed / reflexed hybrid is possible - like the Mission 752F or this :
http://home.hetnet.nl/~geenius/Auriga.html
but not ideal as a good "fat" reflex tuning is not possible, here
the 52 Hz or even slightly higher reflex tuning should be used.
8 ohms all the way - ~ 85dB/W.
(Though it could be wired for 2ohm and ~ 91dB/2.83V.)
f) sealed alignments are not critical 3 to 4 litres per driver seems fine.
g) With a low Q driver the DCR of the series inductor affects Qts.
🙂 sreten.
Just some thoughts on said drivers :
a) without a subwoofer ported is the way to go, with
a subwoofer sealed in fine, also sealed is fine for very
compact speakers.
b) the tiny Vas (hence highish Fs) makes large box
alignments pretty pointless as Vas dominates.
c) tuning to 45Hz is about as low as you can go for minimum F6.
d) for 2 drivers a 2 way MTM with BSC or 2.5 way can be used -
4 ohm in the bass - ~ 85dB/2.83V.
d) for 3 drivers per speaker a 3 way is best, 2 for bass reflexed,
one sealed for midrange - 4 ohm in the bass ~ 85dB/2.83V.
e) for 4 drivers they need to be used in series pairs, a
2.5 way, both MTMMM and TMMMM are possible.
A sealed / reflexed hybrid is possible - like the Mission 752F or this :
http://home.hetnet.nl/~geenius/Auriga.html
but not ideal as a good "fat" reflex tuning is not possible, here
the 52 Hz or even slightly higher reflex tuning should be used.
8 ohms all the way - ~ 85dB/W.
(Though it could be wired for 2ohm and ~ 91dB/2.83V.)
f) sealed alignments are not critical 3 to 4 litres per driver seems fine.
g) With a low Q driver the DCR of the series inductor affects Qts.
🙂 sreten.
Attachments
Well I want in particular a very small box and am not bothered about shear bass extension. This is going to be a standmount speaker not taller then all the drivers in the box if pos. If I was going to make a floorstander out of it then I probably would go ported AND if they were going to be for listening to properly as a main system. As it turns out these are going to be used as computer speakers, I have nowhere left in the house for speakers to go!
A speaker with overall dimensions of 32*15*34 you get an internal volume of about 9.5 litres when made of 18mm MDF.
If you are making a floor stander of the same width then 25cm deep and 83 tall are ported dimensions. So as you can see I cant do ported standmount.
If you do want more bass then go ported! i just prefer sealed and in this application for me size is a contraint. If you wanna go floorstander then by all means do.
Sreten mission 752freedoms are not a hybrid, i owned a pair. They have a top chamber thats ported and a bottom chamber below the top that is also ported, no sealed box anywhere. the 753F speakers have multiple bass drivers so its probably that one your thinking of unles I missed summit.
A speaker with overall dimensions of 32*15*34 you get an internal volume of about 9.5 litres when made of 18mm MDF.
If you are making a floor stander of the same width then 25cm deep and 83 tall are ported dimensions. So as you can see I cant do ported standmount.
If you do want more bass then go ported! i just prefer sealed and in this application for me size is a contraint. If you wanna go floorstander then by all means do.
Sreten mission 752freedoms are not a hybrid, i owned a pair. They have a top chamber thats ported and a bottom chamber below the top that is also ported, no sealed box anywhere. the 753F speakers have multiple bass drivers so its probably that one your thinking of unles I missed summit.
Well AFAIK they are not even that, I removed the bass driver in mine to have a looksee and the top chamber loads the three bass ports on the front about half way up. Then there is a smaller foam filled chamber from the bottom to about 1/4 way up, which is loaded via another port in the back.
Hmm, might have even been the guy who served me when I bought a mic. the other day... 😉richie00boy said:
Another one I talked to once has a lisp and seems like a bit of a geek, maybe it's him???
--
Streten, I was wondering when you'd join this thread 😎
- Status
- Not open for further replies.