Review - JBL P660c

[Firewall]

Before i begin please let me make it clear that i have no background in sound technology beyond what i have read over the years and learned from this and other forums.

I will attempt to provide as comprehensive a review that i possibly can and attempt to answer any questions that you may have.

The songs that i will have used are geared to my listening tastes and may not be decidedly SQ in context.

This will also be a two part review:

1) Firstly the door prep. (damping/deadning)
2) Secondly the impressions of the speaker itself.

So without further ado, here goes.

Vehicle is a 2009 Toyota Corolla

As stated, the first part is about the door prep.

The previous speakers (Mmats CXc6) were mounted in the stock location through the stock riser.

Not much thought was given to install integrity as it was a stop gap measure. (never intended to be permanent)

The door upholstery and the plastic weatherproofing was also removed.

the door was cleaned using simple rubbing alcohol (methylated spirit).

The butyl adhesive used to secure the plastic in place was left since this would be reused.

Before





After





As the rule of thumb, it advises that 25% is enough, but i tried to get about 50-60% coverage.

The reason that this included in the speaker review is so an understanding of the environment that the speaker resides can be understood.

Things left to do are:

1) add a closed cell foam barrier.

the closed cell foam is mainly to be applied as an airborne noise deterrent and the thickness is hoped also to prevent panel rattling.

additional vibration damping materials (MLV's) are not thought to be necessary as there seems to be no need for it when the goals for the install are considered. (guess its basically law of diminishing marginal returns at work here)

2) add something to break up the back wave of the speaker. This will aid in a smoother overall response. (e.g dynaxorb or the secondskin speaker tweaker kit)

3) entirely seal the gaping holes in the door.
considering this but i have yet to determine the best way to proceed. so far fiberglassing inserts seems to be the choice since the contours are too erratic to use MDF.

pics of the back door, just cause........

Before:





After:

[Firewall]

now the "fun" part:

Firstly lets have a look at the components:

textile dome tweeter:





tweeter mounting options:



i like this option as it would help with aiming both tweeters easier


mid woofer:



passive crossover:



The build quality of the speakers are of the highest standard and feels extremely sturdy and durable. Also the integrated tinsel leads come as something of a surprise to me.

The components are run passively and are being powered by this:



3/4" MDF baffles with a 45 degree chamfer around the circumference of the inner hole (to ensure the backwave was not affected) were mounted to the door.

The mid woofer was mounted to this assembly.

The passives were mounted inside the door (not the perfect position, but the only place that they could be mounted presently).

The tweeters were mounted in the stock location in the door.

At this point, i will be remiss if i do not mention that this vehicle was not setup with the intention of SQ and competitions, (i.e imaging and soundstage were not a focus but can be achieved via further install tinkering)

At first i set the crossover on the amp to 80Hz, (felt fairly safe doing this since i had a -24db slope on the amp ensuring a very steep roll off).

Lacking a dmm, i attempted to set the gains by ear. after this was achieved, the volume was lowered.

Then began the process of dialing it in. Due to the lack of a sub, the eventual setting was around 48Hz (within the speaker parameters, but a bit low for the initial period of play.....again felt confident due to the crossover slope)

First Song: 4 Strings - Take me away:
if you recall the image dynamics install where i said the bass was a bit "laggy" for techno, there were no such problems here. The bass response was tight and focused, while the vocals were warm and defined. The highs were a bit sharp so there were attenuated at the passive.

Second Song: Stereo Love Molella Remix:
The accordion at the start of the song was very well defined and the set was able to handle the bit from 1:13 where everything seems to converge quite easily without becoming fuzzy. The highs here seemed to be too muted for this song, so the passive was cut back to 0db which basically fixed it.

(instead of opening the upholstery for every song which would be a pain, i used the 7 band from the deck to adjust the highs to suit) eventual setting was -2.

Third Song: Konshens - "Gyal Dem A Talk" (Clean)
Although this song doesn't have true sub bass material, nor any intricate vocals that would test performance, i think that it is a decent candidate for low midbass, and therefore it was used. Even without the door perfectly sealed (the big gaping holes in the metal) the midbass response was phenomenal. The speaker played straight to my pre-selected upper volume limit (just before distortion) without any hint of break up.(in no small part to the deadning of the doors)

there were other songs used for initial testing but i can't go into or even remember all of them

In the 2 months now that i have been using this set, i have yet to find a song that did not sound tonally accurate.

The greatest testament to this set that i can think of is this:

my previous system was 2 elemental designs 13Ov.2 off a crossfire 1400d, now, i don't run a sub. (it won't replace the heart stopping bass that you are accustomed to, but it just sounds so good and balanced to listen too (with literally any type of music) that you won't miss it as much.

(and it does get get seriously loud.........sorry CBH )

can't think of anything else right now, if i do i will update to suit and try to answer any questions...........assuming anybody reads this

[- Rovin's car audio -]

personally i find d sound deadening to be a bit scanty but nice write up ...

[evolution7tt]

Great Review. Thanks for posting. And that's some great equipment you got there.

You said that the tweeter is mounted in the stock location in the door. Close to the sail panel??

[viking1705]

nice equipment i always loved jbl comps..could have held back on the back doors dampening imo and done the front better.otherwise very nice write up and nice work especially for a diy..well done.

[Firewall]

evolution7tt:
its actually in the sail panel, and if i were to say, they are off axis.

(...Rovin...):
at first i thought it was a bit less (more applicable the back doors), but the reasoning behind it was this:

initially, there was to be the SA-12 bass line, so i tried for the minimum 25% on all metal surfaces (which would be added to after rattles were identified). Then the excess material after the 25% was achieved, was used on the front doors. The back doors do not have any speakers and i don't have any sub, so apart from road noise, i don't know if it plays any significant role.

Complete coverage was attempted on the flattest part of the metal (i.e the outer door skin behind the glass) since this would be most likely to resonate and vibrate. The inner door skin was not flat with many curves and "waves" which provided more stability than was afforded the outer piece, so i thought it would require less. Also i did not want to cover any screws/bolts in case of problems later on.

I don't think that i will add anymore deadning to the doors , but i will attempt to seal the holes and add the closed cell foam to all parts (both for airborne noise and panel rattles)

thanks for the responses and tips, and if you all think that i could change/add anything let me know

[silent_riot]

Fall een on the 14th, let's hear it.

[Chiney]

good stuff there!!

[pimptacular]

what is the material on that cone? because the woofer looks alot like the oz audio matrix elite woofers.. and i know jti had owned oz audio before they went under which is the same owner as jbl i believe unless im wrong

[archangel2011]

nice!can you provide some more pics of the install especially woofer and tweeter locations.I'm thinking about going with these same components even though i have a wingroad.heard four of these in a mazda sedan on jbl amp with 12" jbl power sub.sounded pretty clean and loud enough for me.

[3stagevtec]

Nice writeup! I always wanted to own a set of those power series components.. JBL FTW..

[nervewrecker]

whats the retail price on these & where you located (can I get a small demo).

[Firewall]

pimptacular:
not really if you see it up close, but kinda from far.
they say its a honeycomb laminate and if you look closely, it actually has a honeycomb shape.
The OZ is a glass fiber composite cone.

look a better pic showing the cone:




archangel2011:
i don't have actual installed pics now, but will open the door again after divali to add the closed cell foam so will take them then.

3stagevtec:
thanks man

slacker_jack
I'm up in St Augustine, and no scene on the demo, will just have to organize the time

Retail Price: $1000-$1200

[carfreak1024]

^^^^^yeah count me in for the demo.

[pimptacular]

well the oz the last models they made before they went under was

a 3layer glass fiber and a nomex woven cone in a honeycomb matrix, butyl rubber surround.. ill snap a picture as i suppose to still have them lying around somwhere but thats why i said they look very close

[Firewall]

well the oz the last models they made before they went under was

a 3layer glass fiber and a nomex woven cone in a honeycomb matrix, butyl rubber surround.. ill snap a picture as i suppose to still have them lying around somwhere but thats why i said they look very close

wawz didn't know that, and that supposed to be my second favorite speaker

[archangel2011]

looking forward for the pics after divali.where did you buy it though for that price?

[nervewrecker]

Third Song: Konshens - "Gyal Dem A Talk" (Clean)
Although this song doesn't have true sub bass material, nor any intricate vocals that would test performance, i think that it is a decent candidate for low midbass, and therefore it was used. Even without the door perfectly sealed (the big gaping holes in the metal) the midbass response was phenomenal. The speaker played straight to my pre-selected upper volume limit (just before distortion) without any hint of break up.(in no small part to the deadning of the doors)

this low midbass you speak of, is it both notes or only the higher of the 2 notes?

[Brian Steele]

First Song: 4 Strings - Take me away:[/color]
if you recall the image dynamics install where i said the bass was a bit "laggy" for techno, there were no such problems here. The bass response was tight and focused, while the vocals were warm and defined. The highs were a bit sharp so there were attenuated at the passive.

Interesting choice for testing front speakers. I've got that CD, and I've found that tune a bit too compressed and the bass a bit too rumbly for serious testing. Now, "Fly Away", off the same album, is a great way to not only test bass (both mid and low) response, but find those pesky rattles that tend to show up when the door speakers are asked to produce anything below 100 Hz. They should show up very quickly in the first few seconds of the track as you turn it up.

Another tune I've used for testing - "I'm coming out" (Diana Ross) - stop laughing, LOL. REAL drum kit at the start of the track - great for testing midbass response.

[Firewall]

both notes,

the lower one is supposed to be 45 Hz and the upper is supposed to be 87Hz

remember the LPF was set to 48Hz, so there will be a rolloff that would prevent the speaker from bottoming out at the higher volume, but still give "just" enough at that high volume to not loose the effect completely

[nervewrecker]

both notes,

the lower one is supposed to be 45 Hz and the upper is supposed to be 87Hz

remember the LPF was set to 48Hz, so there will be a rolloff that would prevent the speaker from bottoming out at the higher volume, but still give "just" enough at that high volume to not loose the effect completely

damn! I dont get anything with the lower note.

I will try & organize a day next week to come get a demo as I actually had these same speakers in mind & for the same use.

[Firewall]

First Song: 4 Strings - Take me away:[/color]
if you recall the image dynamics install where i said the bass was a bit "laggy" for techno, there were no such problems here. The bass response was tight and focused, while the vocals were warm and defined. The highs were a bit sharp so there were attenuated at the passive.

Interesting choice for testing front speakers. I've got that CD, and I've found that tune a bit too compressed and the bass a bit too rumbly for serious testing. Now, "Fly Away", off the same album, is a great way to not only test bass (both mid and low) response, but find those pesky rattles that tend to show up when the door speakers are asked to produce anything below 100 Hz. They should show up very quickly in the first few seconds of the track as you turn it up.

Another tune I've used for testing - "I'm coming out" (Diana Ross) - stop laughing, LOL. REAL drum kit at the start of the track - great for testing midbass response.

Remember i'm not too into SQ, and the songs that i chose were not based on the usual SQ testing but on what i mostly listen to.

Take Me Away, Bonnie Portmore and Africa are a few of my favorites, so those were on hand to use. I mean its not album quality, but the highest bitrate mp3 i could find.

i will try to find those that you mentioned and give them a listen (really hoping to kill off the panel rattles that are popping up)

and lastly, what's your opinion of Yanni - The Concert Event as a means for testing? there are a wide range of instruments and vocals in there and its quickly becoming my favorite DVD

thanks for the input

[Firewall]

both notes,

the lower one is supposed to be 45 Hz and the upper is supposed to be 87Hz

remember the LPF was set to 48Hz, so there will be a rolloff that would prevent the speaker from bottoming out at the higher volume, but still give "just" enough at that high volume to not loose the effect completely

damn! I dont get anything with the lower note.

I will try & organize a day next week to come get a demo as I actually had these same speakers in mind & for the same use.

remember the doors deadened too so you could probably try that with your original set first

[Brian Steele]

Remember i'm not too into SQ, and the songs that i chose were not based on the usual SQ testing but on what i mostly listen to.

I don't know if it would be accurate to describe my car audio system as an "SQ" system. It can do SQ, but normally it's mostly tuned for listenable weekend fun, i.e. fairly flat down to around 150 Hz and starting to ramp up below there, and a slight dip and peak around 3kHz. It's also mostly tuned to get fairly loud without distortion, so the fronts are actually crossed @80 Hz 12dB/oct and then again at 40 Hz 12dB/oct. This allows me to get enough midbass up front at higher volumes without noticeable distortion. I've found 4String's "Fly Away" to be a good tune for getting the mix of gain and filters right, and of course for finding buzzes and rattles. As for source material, these days it's a lot of "old-school" rave/techno, like Hyperion's "Ocean of Light" (still searching for the club mix version of that) and Armin Van Buren's "Shivers".

and lastly, what's your opinion of Yanni - The Concert Event as a means for testing? there are a wide range of instruments and vocals in there and its quickly becoming my favorite DVD

I haven't heard that DVD. IMO, the best test material is something that's not overly compressed (which removes about 99% of current pop material from the equation, LOL) and offers good variation between simple and complex passages and of course different types of bass, and of course something that's close to what you're going to be normally playing in your car - no sense tuning your car to do the "1812 Overture" when your tastes run to Iron Maiden . What's most important however IMO is that you be VERY familiar with how the source material sounds on a good system, so you've got a "reference" to work with.

[Firewall]

What's most important however IMO is that you be VERY familiar with how the source material sounds on a good system, so you've got a "reference" to work with.

very very true and i'm trying to organize to get this done.

so the fronts are actually crossed @80 Hz 12dB/oct and then again at 40 Hz 12dB/oct.

not too sure i understand what you mean by this, can you elaborate a little please?

[Brian Steele]

so the fronts are actually crossed @80 Hz 12dB/oct and then again at 40 Hz 12dB/oct.

not too sure i understand what you mean by this, can you elaborate a little please?

Simple - my deck is a Premier 980BT and my front speakers are driven by an old MTX4160 bridged to do 160Wx2 into 4 ohms. There's no way no how iddy-biddy 6.5" drivers are going to handle 160W full range, so I've engaged the 80Hz HP filter on the deck and set the HP filter on the amp to its lowest setting (40 Hz). The gain on the amp is also set so that it does not audibly clip before the "50" setting on the 980BT. The end result is (1) a curve that accelerates from 12dB/oct to 24dB/oct from 80 Hz down, (2) good midbass response up front without noticeable distortion even at pretty high volumes and (3) front speakers that so far have survived the most drunken of "pump-the-volume-to-the-max" after-party excesses since installation .

[Firewall]

gotcha, quite forgot about headunit crossover.

i have the JVC AVX810 and i believe that the HP filter is set at either 80Hz or 63Hz, (can't believe that i forgot that) but i'm not too sure as to the crossover slopes (6/12db) of the deck.

thanks again.

[Brian Steele]

gotcha, quite forgot about headunit crossover.

i have the JVC AVX810 and i believe that the HP filter is set at either 80Hz or 63Hz, (can't believe that i forgot that) but i'm not too sure as to the crossover slopes (6/12db) of the deck.

thanks again.

It's likely 12dB/oct. If you've got it engaged at 80 Hz, and the amp HP engaged at 80 Hz 24db/oct, the end result is likely a pretty steep filter with little chance of overexcursion at higher volumes. I suggest experimenting a bit, like setting both to 63 Hz for example. Might get a little more midbass up front.

[Firewall]

i'll recheck the deck tomorrow, but the amp is set to 48-50 Hz.

weekend i'll start back from scratch and see how it goes. probably add the alpine type E i have sitting around.

will also try the yanni DVD as a source, take a couple vids and see from there.

will keep updating and thanks a million for the help thus far

[nervewrecker]

both notes,

the lower one is supposed to be 45 Hz and the upper is supposed to be 87Hz

remember the LPF was set to 48Hz, so there will be a rolloff that would prevent the speaker from bottoming out at the higher volume, but still give "just" enough at that high volume to not loose the effect completely

damn! I dont get anything with the lower note.

I will try & organize a day next week to come get a demo as I actually had these same speakers in mind & for the same use.

remember the doors deadened too so you could probably try that with your original set first

already did that & even before I added the midwoofers there was a significant increase in the midbass from the stock door speakers.
so far I did my build with slight deadening but when I am upgrading some more deadening will be added & the gaping holes on the doors covered with 1/2" mdf. there are some pics of my door build in here: http://www.mktrinievents.com/forum/phpB ... =14&t=3450

I will definatly try crosing like what brian mentioned in this thread over this weekend.