Your concern for goldfish is commendable, the article is already dumbed down and if you want it dumber ask Rod about it.
From the article what should happen is that too high a compliance should result in vas being higher and fs being lower, if too low then the opposite.
If the driver has a lot of loss then qt should be lower than quoted.
From your data it seems that the drivers have compliance in the low range.
By measuring vas you can get a value for compliance from which you can also get a value for mms by measuring fs. you can then get a value for rmt from measuring qt.
What should happen is that compliance and resistance can vary with time and temperature, but only resistance has a large overall effect and it must be large indeed to have a very noticeable one.
What this does is to check your program and measuring technique, if the values you get stray very far outside those predicted, then your measurement is wrong, that is the value of the published formula.
rcw.
From the article what should happen is that too high a compliance should result in vas being higher and fs being lower, if too low then the opposite.
If the driver has a lot of loss then qt should be lower than quoted.
From your data it seems that the drivers have compliance in the low range.
By measuring vas you can get a value for compliance from which you can also get a value for mms by measuring fs. you can then get a value for rmt from measuring qt.
What should happen is that compliance and resistance can vary with time and temperature, but only resistance has a large overall effect and it must be large indeed to have a very noticeable one.
What this does is to check your program and measuring technique, if the values you get stray very far outside those predicted, then your measurement is wrong, that is the value of the published formula.
rcw.
These are sounding good in the test boxes, even though my bass control is at 3 o'clock and my treble at 11. Testing one of the drivers I get Fs 39.2 (up from 37.65), Qt down from .44 to .4, Vas up from 27 L to 30.3. The weather's cooled considerably so I guess I'm in the range where that's affecting the results, as RCW hinted.
Attachments
So now they've settled down about as much as they will, time to stick them their final boxes. These are a couple of 50L chipboard cabs I picked up from the side of the road; I'm in the process of making an mdf front baffle from scrap, the mid enclosure is a piece of PVC pipe cut in half. If they turn out sounding OK, I'll skin them with 12mm ply.
Attachments
The only real numbers that mean anything is the Fs/Qts ratio.
Check that out and see how close each driver is. You will also notice the Fs/Qts ratio doesn't really change much at all after break in.
Finally got these hooked up Fri night, even though I’d had a couple of glasses of red, didn’t make any wiring mistakes!!! Unsober review then… (& I was listening to Hound Dog Taylor): the piezo super tweeters are a little bit forward, but I think I like them like that, you can hear every detail of the cymbals. Xover is 34 ohms in series with .8uF and 22 ohms across the piezo. Mids – wonderfully clear vocals, xover is 78uF – this is how an FR driver should be used…
Lows: plenty of mid bass punch, drums sound great. Lows lows are a bit lacking, box size would need to be a bit bigger to get the most out of these, although I expect this to improve a bit when the 2nd pair of drivers burn in. Xover is 2nd order at ~ BSC frequency (380Hz), 3mH & 68uf – should be 55uF by my calcs but 68 was what I had, & it sounds OK.
Lows: plenty of mid bass punch, drums sound great. Lows lows are a bit lacking, box size would need to be a bit bigger to get the most out of these, although I expect this to improve a bit when the 2nd pair of drivers burn in. Xover is 2nd order at ~ BSC frequency (380Hz), 3mH & 68uf – should be 55uF by my calcs but 68 was what I had, & it sounds OK.
Last edited:
Hi Allen, I wouldn't use them that high, they sounded too rough IIRC. Crossed over 2nd order at around 400Hz they are OK for the bottom end, actually a bit bass heavy in their new location 'caase I went for the full 6dB BSC. These are best used for the lows in a cheap 2.5 or 3 way. If you want a 2 way, consider the Wavecor drivers from Soundlabs:
6.25" - 4 Ohm - Ferrite - WF160WA02 - Soundlabs Group
6.25" - 4 Ohm - Ferrite - WF160WA02 - Soundlabs Group
Well you know how big a S15 Silvias boot is? About half a Commodore I'd say. Would that be alright?
Here’s my story...
I had a pair of 6.5” jaycar response woofers in the rear. They sounded great when at low volumes (although the woofer channel was maxed out). Unfortunately they did get overpowered by the front splits at high volumes. This is because they had to be toned down, otherwise they distort. Thinking about it now, there was no point in pushing them anymore because they just couldn’t be made any louder…
But what I did liked about the 6.5s is that they where more like a bass booster, then the 12” sub I had in before. Which only captured sub-50Hz and was practically useless for such music as trance, or anything not bass heavy.
So I thought a size up would do the trick, and they should compliment the fronts at low volumes as well as high. But I also thought, if I got more then 8”, then it wouldn’t capture the high-end bass. Does the 8” capture it anyway?
Then again, to be completely honest I don’t know what the 6.5s went up to. Think 500Hz.
Here’s my story...
I had a pair of 6.5” jaycar response woofers in the rear. They sounded great when at low volumes (although the woofer channel was maxed out). Unfortunately they did get overpowered by the front splits at high volumes. This is because they had to be toned down, otherwise they distort. Thinking about it now, there was no point in pushing them anymore because they just couldn’t be made any louder…
But what I did liked about the 6.5s is that they where more like a bass booster, then the 12” sub I had in before. Which only captured sub-50Hz and was practically useless for such music as trance, or anything not bass heavy.
So I thought a size up would do the trick, and they should compliment the fronts at low volumes as well as high. But I also thought, if I got more then 8”, then it wouldn’t capture the high-end bass. Does the 8” capture it anyway?
Then again, to be completely honest I don’t know what the 6.5s went up to. Think 500Hz.
CW2196 & Jaycar Catalogue
Hello from Tassie.
I just posted a question about this speaker and the fz chart that is supplied by Jaycar.
I hope someone from Jaycar is logging in every now and again because I find it very frustrating when I find these things out AFTER I buy a speaker for a particular purpose.
The CW2196'S predecessor (CW2110) was described correctly as far as f0 is concerned, I put two of them in a sealed 32lt box - salvaged from an old bass combo amp - swapped the dead 12" for two 8's and poked a silk dome tweeter in there too! [a tight squeeze but they fit diagonally] the enclosure measures 17" sq by 6" deep inside and It is the best sounding home-made speaker I have - (probably shouldn't say that!).
On the other hand I purchased a CW2199 12 months ago and just got round to measuring that one. It was described as a subbie, but I have a piezo horn that goes lower and louder! - just kidding, BUT it was listed as 23.1Hz and turns out to be bang on 28Hz which is what is printed on the Jaycar label on the back.
So, here's my question, where do they get these figures? It's one thing to make the occasional 'typo' or a bit of a 'blue' - I wouldn't hold that against anyone, but is that what is actually happening? Alltronics have quite a few 'typo's' in their cattle dog also. I guess it's a case of buyer beware.
Sincerely, Phil E.
Hello from Tassie.
I just posted a question about this speaker and the fz chart that is supplied by Jaycar.
I hope someone from Jaycar is logging in every now and again because I find it very frustrating when I find these things out AFTER I buy a speaker for a particular purpose.
The CW2196'S predecessor (CW2110) was described correctly as far as f0 is concerned, I put two of them in a sealed 32lt box - salvaged from an old bass combo amp - swapped the dead 12" for two 8's and poked a silk dome tweeter in there too! [a tight squeeze but they fit diagonally] the enclosure measures 17" sq by 6" deep inside and It is the best sounding home-made speaker I have - (probably shouldn't say that!).
On the other hand I purchased a CW2199 12 months ago and just got round to measuring that one. It was described as a subbie, but I have a piezo horn that goes lower and louder! - just kidding, BUT it was listed as 23.1Hz and turns out to be bang on 28Hz which is what is printed on the Jaycar label on the back.
So, here's my question, where do they get these figures? It's one thing to make the occasional 'typo' or a bit of a 'blue' - I wouldn't hold that against anyone, but is that what is actually happening? Alltronics have quite a few 'typo's' in their cattle dog also. I guess it's a case of buyer beware.
Sincerely, Phil E.
Well for a start speakers are now such a small part of the jaycar business that I don't think they go to too much trouble, but also the QC at production is such that there can be a wide variation in spec. Remember that even with good production facilities and good quality control that 10% plus or minus would be expected.
I have had some 10 inch woofers that spec'd at 30hz and a mate measured at 19 and 42
I have had some 10 inch woofers that spec'd at 30hz and a mate measured at 19 and 42
It's pretty hit & miss with Jaycar drivers, I've had some good, & some not so good but usable within their limitations, it's impossible to tell if the specs are before or after break in.
To me it seems that Jaycar stuff is built to a price.... a low price.... the only advantage they have is that for most people they're easy to get to. There are better value drivers out there in Aus if you want to look around, e.g. Wavecor drivers...
To me it seems that Jaycar stuff is built to a price.... a low price.... the only advantage they have is that for most people they're easy to get to. There are better value drivers out there in Aus if you want to look around, e.g. Wavecor drivers...
I will have a look at that Soundlabs site a little later this week when i finish mowing the lawns, washing the dishes, building those boxes, and taking tea with my 'oldies'.
BTW, I purchased a huge great db meter (moving coil 8" diameter!) off the ebay site last week and I am just knocking up a rectifier come integrator for it - so that it measures peak/vu. I am going to slap it in the front of one of my 120lt subbies just to be a duffer. Or should that be "a doofer"!
Cheers fellas
BTW, I purchased a huge great db meter (moving coil 8" diameter!) off the ebay site last week and I am just knocking up a rectifier come integrator for it - so that it measures peak/vu. I am going to slap it in the front of one of my 120lt subbies just to be a duffer. Or should that be "a doofer"!
Cheers fellas
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.