With all due respects AJ, sreten and infinia have hit the nail on the head by providing useful tips, but it's falling on deaf ears.
#1 problem with with typical off-the-shelf active crossovers and textbook passive crossovers is the lack of diffraction loss compensation. As you know AJ, this results in a loss in frequencies below 400-600Hz (for typically narrow 20-25cm wide baffle), and subjective sound that generally sound "very clear" in the lower midrange/vocal frequencies, but lacks low mid "warmth" or any kind of bass.
300Z is still complaining about lack of midbass, turned off by RS180 whilst using it in a active setup etc.
300Z- have you implement the diffraction loss compensation? We're still that square 1 here...
#1 problem with with typical off-the-shelf active crossovers and textbook passive crossovers is the lack of diffraction loss compensation. As you know AJ, this results in a loss in frequencies below 400-600Hz (for typically narrow 20-25cm wide baffle), and subjective sound that generally sound "very clear" in the lower midrange/vocal frequencies, but lacks low mid "warmth" or any kind of bass.
300Z is still complaining about lack of midbass, turned off by RS180 whilst using it in a active setup etc.
300Z- have you implement the diffraction loss compensation? We're still that square 1 here...
You compared both drivers with measured Qtc being the same?
The driver with the lower xmax produced more slam? Could it be the greater distortion adding more perceived bass? Perhaps it has more slam indeed.
300Z, does the box have any damping?
It sounds to me (no pun intended) very much that this is a haphazard enclosure than an optimized, tuned one. Without measuring capability it is usually best to go with a proven design.
Did you do at least some rudimentary design modeling with freeware like WinISD, etc?
cheers,
AJ
Like i said, the x-over is just a simple low-pass and hi-pass filter... No BSC, diffraction loss compensation were implemented...
The front baffle measures 8 3/4" x 18"...
The box has 2 1/2" thick Acoustic open cell foam (egg crate kind) lined on the inside walls...
Before i built this box i did some modeling using Bass Box Pro6 and WinISD and the response just had like a ~2-3db bump at ~50hz and was overall smooth beyond that.
I do plan to start this from scratch and just do it right this time around.
Guys I'm not complaining about lack of midbass output but a tonality issue.
Thanks
Leo
The front baffle measures 8 3/4" x 18"...
The box has 2 1/2" thick Acoustic open cell foam (egg crate kind) lined on the inside walls...
Before i built this box i did some modeling using Bass Box Pro6 and WinISD and the response just had like a ~2-3db bump at ~50hz and was overall smooth beyond that.
I do plan to start this from scratch and just do it right this time around.
Guys I'm not complaining about lack of midbass output but a tonality issue.
Thanks
Leo
Sorry guys, i'm trying to provide as much info as i can... but it seems i'm still falling at doing so... 
I'm actually more interested in just building a new speaker from scratch using a different mid.
If i could build a new network for the existing speaker that would be fine too, but i still would like to build the new speaker and could use the old one as a start point for comparisons l8r on...
Thanks
Leo
I'm actually more interested in just building a new speaker from scratch using a different mid.
If i could build a new network for the existing speaker that would be fine too, but i still would like to build the new speaker and could use the old one as a start point for comparisons l8r on...
Thanks
Leo
Leo,
you did wire the tweeter and woofers with the same polarity using the LR4 correct? Generic XO's are a car audio thing, they don't apply real well in the real world.
Or, maybe as you said from the start, the drivers don't have what you perceive as correct, balanced tonality. Subjective impressions of different individuals can be, well....different.
Have you tried them out on stands with some active eq?
cheers,
AJ
you did wire the tweeter and woofers with the same polarity using the LR4 correct? Generic XO's are a car audio thing, they don't apply real well in the real world.
Or, maybe as you said from the start, the drivers don't have what you perceive as correct, balanced tonality. Subjective impressions of different individuals can be, well....different
.Have you tried them out on stands with some active eq?
cheers,
AJ
Well, I tried the the tweeters wired in phase (electrically) with the mids, out of phase and just one of the tweeters out of phase from the other. Can't remember what i ended up with...
Even when playing free air I can tell the mids don't sound "pure"... know what i mean?
I never tried the speakers on stands... Guess i'll have to find some way to try that since i don't have speaker stands...
Leo
You got that right...AJinFLA said:Or, maybe as you said from the start, the drivers don't have what you perceive as correct, balanced tonality. Subjective impressions of different individuals can be, well....different
Even when playing free air I can tell the mids don't sound "pure"... know what i mean?
I never tried the speakers on stands... Guess i'll have to find some way to try that since i don't have speaker stands...
Leo
300Z said:
I think i'll give it another shot using the PL's... I don't have the RS180's anymore (gave it to a friend)...
What x-over modeling program do you guys use?
Any1 ever did a project using the PL18's 4ohm version? I tried search but no luck...
Thanks
Leo
You have a baseline design right. I would post what you have now ie schematics, and box design. Use it for a start, and AJ since he seems interested can walk you through his process. I'll be the student as well.
I know your knowledgable and experienced enough that numbers can't describe how a driver will sound and/or perform.
The original poster said "not loud".. Zaph's measurement's put this driver in the same league as the Seas L18.
http://www.zaphaudio.com/6.5test/
454Casull said:
They can give clues..
Not neccesarily great for the subjective impression of "tone" though..
For instance the sense of "punch" in the lower midrange, (cavity resonance region near 80 Hz), is not simply a matter of spl in that passband.. (..though obviously IT is important and needs to be relativly near reference level). (..note though that depending on the driver - it could be noticible even if down as much as 9 db from the reference - which is more than average baffle step loss.)
Both mms, Bl, and Qms play their part here. IF you also want "punch" thats "fast" then you'll need efficiency as well.
In addition (as AJ mentioned), there is also the question of driver loading and how that will factor-in, particularly with regard to system compliance (or more specifically - lack thereof).
Either higher force (Bl), or greater mass (mms), for a given surface area (sd) increases the sense of "punch" (..IF of course the driver operates in the appropriate passband mentioned).
A less compliant spider (i.e. a lower Qms) also increases the sense of "punch", THOUGH system compliance seems to factor in more than driver compliance. (This is largely due to the resonance of the driver invariably being raised in-box and presenting a large amount of back emf in this region that is effectivly "slamming" against the amplifier's current - and yes, it IS distortion).
Note however that increased mass invariably decreases natural decay and "tone". So there is "give and take" here.
300z: If your looking for something that exemplifies "punch" in this region then consider the ciare 8.64 Nd W from Assistance Audio in the US. It has the spec.s and is eff. enough to be "fast" sounding while having enough gain for a shelving filter for your baffle-step compensation with most tweeters. It isn't cheap - but then it isn't cheap. It will of course require a "steep" lowpass crossover below 2 kHz for both limiting its "break-up" region and because of directivity. A sealed enclosure will maximise the sensation of "punch" further (depending on the pairing amplifier), but at the expense of gain (..unless of course your sub.s are crossed quite high in freq.). Of course a bass reflex design (non-aligned - think EBS) will still provide pleanty of punch and give you considerably more gain below 100 Hz. - Just a suggestion..
The bassrolloff at around 100hz for the SI-Amp is quite well documented. You wont get loud with an amp that puts out only 6 watts too
http://www.michael.mardis.com/sonic/measure/default.html
http://www.michael.mardis.com/sonic/measure/default.html
Hi Scott, thanks for your input.
I looked at the Ciare driver you listed, and that driver only has 1.5mm of x-max and a .24Qts... Low excursion and low total Q doesn't seem to be a good combo for sealed boxes don't you agree?
Instead i'm looking into the B&C 8NDL51 which has quite bit more excursion than the Ciare but still has good efficiency.
I would really prefer to just build a new project using different mids rather than just building a new network for the ones i have.
Oh, and the SI T amp isn't the only amp that i have used to power these speakers, I mentioned it earlier...
Leo
I looked at the Ciare driver you listed, and that driver only has 1.5mm of x-max and a .24Qts... Low excursion and low total Q doesn't seem to be a good combo for sealed boxes don't you agree?
Instead i'm looking into the B&C 8NDL51 which has quite bit more excursion than the Ciare but still has good efficiency.
I would really prefer to just build a new project using different mids rather than just building a new network for the ones i have.
Oh, and the SI T amp isn't the only amp that i have used to power these speakers, I mentioned it earlier...
Leo
I disagree, the numbers can't tell you exactly how a driver will sound, but if you know what to look for, they can tell you a lot a lot like what it can sound like.
Do you know how that driver itself was designed? By numbers.
"Punch" and "Slam" are subjective terms that can mean different things to different people. I would associate both more with box tuning - which is of course symbiotic with the driver. I would also associate it with (much) higher than just low volume listening.
Which is why I asked if you had compared both with Qtc measured equal. If you did and the DA175 still had more "slam" - to your ears - then I have no qualms with that assessment.
I am also well aware of Zaphs tests and their implications. Which driver do you think will have more distortion when driven to 4mm of excursion? Do you also understand that distortion can impart a sense of "more" bass? I'm not saying that this is what you are hearing, but it could certainly be a factor.
At work so I'll have to address Leo later
cheers,
AJ
300Z said:
It all depends on what you are looking for from your passband. (..and its why I mentioned an alternative to a sealed design.)
With an appropriate shelving filter the ciare's response will start to decline around 150 Hz. HOWEVER that decline won't be to bad considering room gain (..and should only be down about 2-3 db at around 70 Hz). Now an EBS reflex design would not only decrease non-linear distortion but also give a flat in-room response to 50 Hz. (excepting room modes). (..and of course you could "tailor" the port's resonance for your listening position and integration with the subwoofer.)
Do NOT get "wrapped" up in excursion unless you intend to create a system that will "tax" the driver's excursion capability..
Overall the B&C will not be as good a driver, but that isn't to say it will be bad either. The only thing that bothers me about it is the break-up region which extends lower in freq. (..practically on top of the crossover region). This also suggests poorer off-axis radiation which further compounds the problem of the crossover region.
The other B&C driver (8pe21) goes further in the other direction - effectivly leaving the ciare to split the difference between the two. Note the gauss/magnetic induction/flux density of the drivers - this often relates to "transparency" to some extent. In this respect the neo motor of the ciare betters both B&C drivers.
In any event - all of these 8 inch drivers will require an extended low freq. response from the tweeter. Either a driver built like this, or with a bit of horn loading lower in its passband via a waveguide.
Zaph has both a tweeter like this (the scan speak air-cir.) on his site AND a waveguide implementation.
RJ said:
That doesn't put it in the same league as the L18 from my point of view...
What I mean by the speaker lacking "snap" is when compared to a real instrument while played unamplified. The speaker just lacks the accuracy to reproduce the tone with the same tonality as the real unamplified instrument.
Hope that makes things a little more clear...
Do I still need to account for such network implementations in an active setup?sreten said:Hi,
I'll just add again that discussing the relative merits of
drivers when a crude crossover is used is fairly pointless.
When I "evaluate" a driver i try to listen to it free air just to get an overall idea of how said driver potential rather then the whole system...
Leo
I guess I'm just looking for a driver with high resolution/transparency, low distortion and capable of flat response to ~60hz where I can just use to sub from there (lower would be a plus of course)...ScottG said:
Never heard of this before... gotta investigate that further...
As for using 8" mids, I would actually prefer to use a 7" due to box size requirements, but as long as the box isn't too big i guess that shouldn't matter?
I already have the tweeter (Dayton RS28A) and I would think it qualifies as a good tweeter for this app?
Waveguides, that's another option that has also crossed my mind.
But right now I'm just wondering if it's still worth to go thru all of this or just get a pair of LSR6328P ?
Thanks all.
Leo
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