DiyMobileAudio.com Car Stereo Forum banner

1 - 19 of 19 Posts

·
DIYMA Founder
Joined
·
4,757 Posts
Discussion Starter #1 (Edited)





I picked these up for $120/pr at Partsexpress with free shipping. They're very nice looking drivers, and the weight and feel of the mid is solid. I especially like the protective mesh grille and thick aluminum mounting flange.

What I didn't like however was the somewhat ordinary looking motor. Sorry folks, no copper rings or sleeves in this motor, unlike their larger cone mid/bass and tweeters. I would have also liked to see a larger, more solidly constructed rear chamber instead of the plastic used in the back. The wool/felt padding stuffed into the rear chamber was a nice addition however.

A quick semi-anechoic frequency response plot. Notice the dip centered at around 3.8khz.



And here's the distortion plot from 300hz to 6khz. This is at 2w or roughly 96db spl. Very loud, painful listening levels.



This unit is pretty good distortion wise, except for between 1khz and 2khz. This is pretty obvious if you've read the tutorial in the diy article forum. Third order distortion (blue line) is considered fairly offensive, and 1-2khz is the range of human hearing that is especially sensitive to small levels of distortion. I would consider nearly 2% third order distortion between 1-2khz to be pretty poor performance. You could also notice that the third harmonic of 1khz-2khz corresponds to the dip shown in the frequency response plot. Coincidence?

From 2khz and up however, this driver is exceptionally clean. Below 600hz is only average, but I wouldn't use this dome mid below that in any case. Not only does second order (green line) distortion increase, but the rear chamber is simply too small and made of plastic... which leads to an audible resonance and a sort of "echo" effect that muddies up the sound. I'd keep this driver highpassed at 600-800hz.

So how did it sound? Using the Usher demo discs I listened to several vocal and guitar tracks. When highpassed at 650hz second order (12db), this mid sounded great. Very smooth, natural, and open sounding. Detail is definitely up there with some of the best cone mids I've heard like Scan -Speaks Revelator or Seas Lotus reference/Excel. It's also a bit laid back in the upper frequencies, but that was fine with me as I noticed some tracks that usually (and should) sound peaky or forward were more listenable. I was surprised that the distortion between 1-2khz wasn't really that big of a deal. Perhaps the fact that there's a -5db dip centered around 3.8khz helps to mellow out the sound.

Sensitivity is also better than your average cone mid. I recorded close to 93dbwm. Dynamics don't seem to be a problem either, and is actually quite good provided you are highpassing the driver above 650hz.

I'd say for $120 these are a pretty good buy. I like the sound very much, and wouldn't hesitate to say that from 650hz-6khz that this is one of the best drivers I've heard. You can expect a sound that's overall light and open, natural and uncolored, but a bit on the mellow side.
 

·
DIYMA Founder
Joined
·
4,757 Posts
Discussion Starter #2
After living with these for awhile, I discovered that by removing the rear cup from the back of the mid and enclosing them in a larger, sealed box that it improved the midrange quality by quite a bit. The sound became a bit lighter, and more open. This was especially noticeable if you were crossing the driver over lower in frequency.
 

·
Registered
Joined
·
151 Posts
npdang, if you don't mind, I've got a quick 2 part question about running the Ushers with the chamber removed.

1. Without the chamber, how low do you think the Usher could be comfortably crossed over?

2. Would the amount of sealed volume affect the mid? I'm guessing not, since without the rear chamber the mid is probably close to an IB alingment.

Thanks for the info.
 

·
Registered
Joined
·
1,978 Posts
so without considering the obvious price differential

which sounds better overall from 600hz to 4000hz


dynaudio md100
dls ir3
usher dome


hmmmm finally figured out how to get the peerless xls 8" in my doors LOL
 

·
I am Godzilla
Joined
·
107 Posts
Greatly appricate the review and the crossover advice.
I plan on using a pair of these dome mids with a pair of the Usher dome tweets in a 3-way setup with another yet to be deterined driver in a car audio install.
Should be lots of fun.

The Hammer
 

·
Registered
Joined
·
1,124 Posts
npdang: How much lower were you able to cross the Ushers over after removing the back. Was that with a 12 db crossover? Could they be crossed over lower with a 4th order crossover?
 

·
Registered
Joined
·
1,124 Posts
Npdang: You said that the LPG's domes sounded better out of the box than the Ushers.

Was that because of rear chamber resonance? How large was the rear chamber you fabricated for the Ushers? How low would the Ushers go with a fabricated rear chamber? 500hz like the LPG's? Would the LPGs sound better with a larger rear chamber? What would you 'suspect' the best crossover for these domes would be to a LPG tweeter? How would the sound change when crossing over at 4000, 5000, or 6000hz.

Thanks,
 

·
DIYMA Founder
Joined
·
4,757 Posts
Discussion Starter #9
LPG sound better out of the box because they have a wider bandwidth and flatter frequency response.

With the appropriate rear chamber, 500hz shouldn't be a problem for the Usher's although I would use a very steep electrical filter as you're probably at the driver's limits.

I really can't say which is the "better" dome. I would suspect you'd have to look at pricing and availability as well as the range which you plan to use them to come to a decision. If you don't need anything past 2-3khz I'd stick with the Usher.
 

·
Registered
Joined
·
1,124 Posts
Npdang-Thank you for responding to my question. Again this is the best car audio forum out there. Period.

So both Usher and LPG domes have a lower limit at 500Hz. I thought that the Usher had more excursion than the LPG and could therefore get lower at the same volumes. Is the increase in SPL or volume too small to matter?

Also you had stated that the Usher was one of the best mdranges form 650 to 6000hz, but above you imply that the LPG would be better if it was being used beyound 2-3K, why.

Is the DLS mid all hype, and basically just equivalent to these domes at twice the price?
 

·
DIYMA Founder
Joined
·
4,757 Posts
Discussion Starter #11
I really haven't had too much experience with DLS dome mid. It is a larger driver I believe.. which has strengths and weakness. One being more surface area and displacement capability, but then for larger drivers a silk dome probably isn't going to be rigid enough to give a fast response.

I would cross the LPG higher, and steeper than the Usher. It does have a shorter voice coil and excursion.

I think the LPG is better above 2-3khz because it has a flatter response, and lower distortion. The Usher just sounds good between 650hz-6khz... with some equalization although objectively it doesn't perform as well as the LPG.
 

·
DIYMA lurker
Joined
·
802 Posts
Thanks for the review! A couple of questions:

What is the bolt circle diameter of the driver itself (without the metal faceplate)? It all looks huge. I'm trying to find a driver I can fit in my door vents, no bigger than 3.75".

Also, do you think they'd function okay in a poorly sealed or free-air environment? If they replace my door vents, they're going to be inside the A/C pathway.

Dan
 

·
Registered
Joined
·
1,011 Posts
npdang,
how's the directivity of the dome?
I didn't see the off-axis response so I can't tell how it performs at 30+-degrees off axis.
 

·
Registered
Joined
·
1,892 Posts
seems sensitivity is way down on the c version and a few other specs are different as well
 

·
Registered
Joined
·
151 Posts
Newtitan, after browsing through Ushers line-up, it would appear that "C" is the designation they use for the shielded drives.

Does anyone know which of the 9845 variants it is that Zalytron is selling at 45 bucks a pop? If you notice, they list the 9845M, but they've got graphs for 9845 and 8945 (someone got dyslexic?????).
 

·
Registered
Joined
·
1,978 Posts
#1) the zalytron verison is the "c" version, the partsexpress version is the non "c" versiosn

looks at the graphs and specs to see the differences

#2) I dont think the C' version specifies "sheilded" as how would a second magnet and bucking plate cause that much loss of SPL,and resonant frequency?

I know for example on the dayotn rs28. the sheilded version vs non sheilded the resonant frequency changes , but not also the spl?

who knows

anyway heres a response from another member


I honestly did not notice the difference in model
numbers. But, through your links, it seems that the
rear chambers are a bit different in the two models.
The one with the longer (bigger) rear chamber will
play lower and ultimately have a better 3rd harmonics
distortions than the one with a shorter chamber.
I do think the graphs are somewhat accurate since they
do match up with cheapboy's measurements.
Notice that he measured the shorter chamber version
and liked it when the rear chamber is modified. The C
model from zalytron gives the driver more room to
breathe, thus it will have lower fs.

Do notice that you will still have to cross the driver
with a very steep slope since both drivers share the
same motor, therefore, they do have the same limits as
far as excursion goes.

The data showned that the one with a longer chamber
handles less power and have less average sensitivity
are exactly the sacrifices in a driver if it's
modified to play lower.
 

·
Registered
Joined
·
151 Posts
Newtitan, my bad if I got the "C" wrong. Guess its not safe to assume that the darn "C" would mean the same thing throughout the line. :(

Hopefully Zalytron will eventually notice that the data they have posted for the 9845 Dome Midrange, is in fact data for the 8945 7" Midwoofer. :confused:
 
1 - 19 of 19 Posts
Top