Hi All,
I have 2 pairs of 16cm EAS / Matsushita drivers that have been sitting on a shelf in my garage for at least a decade. One pair was pulled from some Panasonic speakers like these that I got from Goodwill for like $5.00 but that had cracked plastic housings:
Vintage PANASONIC SB-84 BARREL SPEAKERS MID CENTURY MODERN HI-FI GEAR JAPAN Cool | eBay
I'm not sure where I got the other pair, but probably from another pair of Panasonic speakers.
I recently listened to them in open baffle and found they didn't sound bad at all.
I'm sure these are high Q drivers but, I was wondering if I could do a ported enclosure for them. Something that might get down to 80-70hz.
R/
Jim
I have 2 pairs of 16cm EAS / Matsushita drivers that have been sitting on a shelf in my garage for at least a decade. One pair was pulled from some Panasonic speakers like these that I got from Goodwill for like $5.00 but that had cracked plastic housings:
Vintage PANASONIC SB-84 BARREL SPEAKERS MID CENTURY MODERN HI-FI GEAR JAPAN Cool | eBay
I'm not sure where I got the other pair, but probably from another pair of Panasonic speakers.
I recently listened to them in open baffle and found they didn't sound bad at all.
I'm sure these are high Q drivers but, I was wondering if I could do a ported enclosure for them. Something that might get down to 80-70hz.
R/
Jim
They bring back some memories. In the early 1970's my older sister had the Panasonic stereo reciever with buit in turntable ontop that those speakers came with.
You really need to measure the driver's TS parameters in order to design a box. Personally, I think you can do a lot better with a budget Mark Audio driver -
maybe this:
Markaudio CHR-70 Brushed Metal Cone 4" Full Range
or this:
Markaudio Pluvia Seven HD 4" Metal Cone Full Range-Chrome
You really need to measure the driver's TS parameters in order to design a box. Personally, I think you can do a lot better with a budget Mark Audio driver -
maybe this:
Markaudio CHR-70 Brushed Metal Cone 4" Full Range
or this:
Markaudio Pluvia Seven HD 4" Metal Cone Full Range-Chrome
I had a pair of those cylindrical speakers in the shop a long time ago.
The drivers are crap, sorry.
Made for a mediocre 5 watt stereo system.
The drivers are crap, sorry.
Made for a mediocre 5 watt stereo system.
In fact, 5 watt peak as it says on the label! 😎
The cylindrical enclosures use somethin akin to aperiodic loading (slits at the rear with foam to provide extra resistance to air flow).
You'd probably be best to stick to the same form of loading, which can be quite forgiving of the actual enclosure dimensions and volume.
The cylindrical enclosures use somethin akin to aperiodic loading (slits at the rear with foam to provide extra resistance to air flow).
You'd probably be best to stick to the same form of loading, which can be quite forgiving of the actual enclosure dimensions and volume.
Attachments
Galu, those rear vents with foam are not designed as some form of "loading" as you say.
They're simply covered in foam to hide the cheap speakers inside and to keep out the dust.
There was nothing "audiophile" about those things.
Well, that is glaringly obvious, wiseold!
I said something 'akin' to aperiodic loading, and still think that form of loading would be preferable to a ported cabinet in this case.
I was offering Jim a practical solution and, hopefully, being more helpful than simply describing the drivers as cr*p! 😉
P.S. A cabinet back designed simply to hide the driver and keep the dust out would not require slots in it at all. So why would the manufacturer go to all that bother? There must be some advantage soundwise in conjunction with these particular drivers.
@ Jim. I would be interested in seeing photos of the actual drivers. I like a bit of diy fun! 😎
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Quite so, I don't think you're likely to be far off the mark with that. 'Loading' in speaker design parlance is commonly employed as a synonym for 'what you do with the driver', and the drivers here clearly are, by definition 'loaded' by the enclosure. From the pictures I would assume they were a cheap high Q unit that was put in what amounted to a half-way-house between an open-back and a [not tightly / very specifically tuned] vented enclosure, which was then lagged with foam to get a bit of damping at system resonance.
At ~6", 5 W, I'm guessing they're basically the same as the small box full of ~6 - 6.5" I've pulled from [discarded] big screen [RP]TVs, cheap stereo AM/FM [clock] radios.
Only crudely measured a few responses by ear, but all were basically ~300-6 kHz for good speech intelligibility, so good enough as a mid in an 'el cheapo' 12-15" woofer + 3/4" VC [super] tweeter multi-way; otherwise leave them in their cabs or of similar net volume [Vb], 'venting' for use as [spare] speakers for a cheap stereo AM/FM [clock] radio.
GM
Only crudely measured a few responses by ear, but all were basically ~300-6 kHz for good speech intelligibility, so good enough as a mid in an 'el cheapo' 12-15" woofer + 3/4" VC [super] tweeter multi-way; otherwise leave them in their cabs or of similar net volume [Vb], 'venting' for use as [spare] speakers for a cheap stereo AM/FM [clock] radio.
GM
The foam provided no "damping", it was thin like an air conditioner filter - quite "open cell".
The speakers I had in the shop sounded like a cheap boombox with no bass to speak of.
And discussing these speakers with terms like Things like "Q" and TS parameters is silly nonsense.
They were crap, period.
Agreed. I had to live with those things playing in the bedroom next to mine!
I do however appreciate Dr. Scott's forensics😉
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Scott's first law of common sense is that it is inversely proportionate to the number of letters people place before or after their own name when they do not need to. Purely by way of explanation, I happen to have a doctorate, which is what our friend is referring to, but I don't use it here myself as it's of no relevance.
Be that as it may, quality factor is a mathematical derivation that can be applied to any MC unit as a simple way of describing their behaviour in the rising response BW, in more or less detail depending on how far you wish to proceed. Some might call that 'silly nonsense', but it happens to be a fact, and others find a basic illustration they can relate to helpful in understanding a general set of characteristics.
Open cell foam does not typically provide much damping, except in very high densities for a given volume. However, like it or not, it does provide some, although in this case it will be small and the vent aspect ratio will probably provide almost as much.
Be that as it may, quality factor is a mathematical derivation that can be applied to any MC unit as a simple way of describing their behaviour in the rising response BW, in more or less detail depending on how far you wish to proceed. Some might call that 'silly nonsense', but it happens to be a fact, and others find a basic illustration they can relate to helpful in understanding a general set of characteristics.
Open cell foam does not typically provide much damping, except in very high densities for a given volume. However, like it or not, it does provide some, although in this case it will be small and the vent aspect ratio will probably provide almost as much.
There was no Dr. Scott in Star Trek. Perhaps you're thinking of Mr. Scott to whom James T. Kirk famously said "Scotty, you're my chief engineer. You know everything about that ship there is to know. More than the men who designed it. If you can't get those warp engines working, you're fired."
And, not to be confused with Science Officer Mr. Spock who would have quickly spotted the illogicality of going to the lengths of giving an enclosure a foam lined, slotted back simply to "hide the cheap speakers inside and to keep out the dust"! 😉
Thank you all for engaging.
IIRC I listened to those speakers and found them OK, with forward vocals and limited bass. I pulled the drivers because they were wide range and had the same basic dimensions as the rotted dash speaker in my '66 VW double cab. Good, plentiful spares.
For those asking for numbers
EAS 16P24sS
and
EAS 16P90sA
I'll have to read on how to post pictures since it's been awhile.
So I put the first pair in some 18W x 22H open baffles to show a friend that speakers don't need boxes to sound OK. (he has some OEM auto speakers that he was wondering what to do with) Once in the baffles "I" was surprised at how they sounded. No, not over the moon surprised but, more like "hey, check it out, I don't have to make excuse's for OB" good sounding. They were obviously volume limited driven by an old SI T-amp. So then I cut the other pair in, now a 4ohm load, and the T-amp did fine. Because of wattage I run them at about 60% but also because if I go beyond that the distortion (or is it the massive peak at 6.3K) becomes annoying. I recently installed .68mH inductors I had on hand on one of the drivers and they sounded even better. I guess the .5 configuration helped balance the FR.
I love OB but OB doesn't love me. Space, especially distance from boundaries. I can never seem to keep it permanent, hence why I was wondering about alternative enclosures. Hey maybe the baffle size really helped out and I'd be good trying a sealed wide x shallow design. Might just do that.
BTW I don't have measuring gear. But on one driver I did a quick sweep on baffle at @ 1m using the frequency portion of Audiophile Test CD. 1K at @1m was 74db. It was pretty flat down to 63hz tone. From 2.5k thru 8k it go progressively hotter (up to 97db at 5k and 6.3k) and was still at 70db at 16k.
Hope this puts some perspective on what I was asking for.
R/
Jim
IIRC I listened to those speakers and found them OK, with forward vocals and limited bass. I pulled the drivers because they were wide range and had the same basic dimensions as the rotted dash speaker in my '66 VW double cab. Good, plentiful spares.
For those asking for numbers
EAS 16P24sS
and
EAS 16P90sA
I'll have to read on how to post pictures since it's been awhile.
So I put the first pair in some 18W x 22H open baffles to show a friend that speakers don't need boxes to sound OK. (he has some OEM auto speakers that he was wondering what to do with) Once in the baffles "I" was surprised at how they sounded. No, not over the moon surprised but, more like "hey, check it out, I don't have to make excuse's for OB" good sounding. They were obviously volume limited driven by an old SI T-amp. So then I cut the other pair in, now a 4ohm load, and the T-amp did fine. Because of wattage I run them at about 60% but also because if I go beyond that the distortion (or is it the massive peak at 6.3K) becomes annoying. I recently installed .68mH inductors I had on hand on one of the drivers and they sounded even better. I guess the .5 configuration helped balance the FR.
I love OB but OB doesn't love me. Space, especially distance from boundaries. I can never seem to keep it permanent, hence why I was wondering about alternative enclosures. Hey maybe the baffle size really helped out and I'd be good trying a sealed wide x shallow design. Might just do that.
BTW I don't have measuring gear. But on one driver I did a quick sweep on baffle at @ 1m using the frequency portion of Audiophile Test CD. 1K at @1m was 74db. It was pretty flat down to 63hz tone. From 2.5k thru 8k it go progressively hotter (up to 97db at 5k and 6.3k) and was still at 70db at 16k.
Hope this puts some perspective on what I was asking for.
R/
Jim
Thanx for the numbers. I have had a bunch of different EAS 16p but none with the same last 2 numbers. Some were quite good, some were not/
dave
dave
Yes Dave,
One pair has a ragged top end, the other is more pleasing. Guess I should freq sweep them both this weekend to find out which one presents hotter than the other and wire the inductor on that one.
R/
One pair has a ragged top end, the other is more pleasing. Guess I should freq sweep them both this weekend to find out which one presents hotter than the other and wire the inductor on that one.
R/