Thought you might be interested in the difference between the stock head unit's freq. response before and after CleanSweep correction. The CleanSweep was connected at the amplifier inputs, all head unit tone controls were set flat.

Measurements were made with 1/3 octave test signals into Sencore AudioPro spectrum analyzer, then imported into an Audio Precision for graphing. As you can see, the stock response is far from flat (especially in the front channels).

Front Channels (Red is before CleanSweep, Blue is after CleanSweep):



Rear Channels (Red is before CleanSweep, Blue is after CleanSweep):



Hope that answers a few questions.

Best regards,

Manville Smith
JL Audio, Inc.

 

Thanks for posting these. Even without the adjustments, frequency response almost makes into +/-3db range, which is not bad. Did you measure on empty car or with driver/ passengers? People inside can change the response.
Or may be I misread your test set up, and you measured only electrical parts of the system?

 

These are strictly electrical measurements, not acoustic. I am simply showing the response of the signal coming out of the radio... a good aftermarket head unit would be ruler flat under the same conditions.

The rears aren't bad at all, but the fronts are pretty messed up... Even though the max deviation is only about +/- 3dB, the shape and the fact that is in the meat of the midrange makes the difference plainly audible. I wouldn't say the stock curve is completely unlistenable with good speakers (like the curve in the MDX's system), but it's not great, either.

Best regards,

Manville Smith
JL Audio, Inc.

 

Those are interesting graphs, but they really don't tell me a thing about the response of the system. If the factory speakers have corresponding dips and peaks in frequency response, leveling the signal would exacerbate them. I'd rather see graphs of acoustic measurements as that's what our ears are hearing. I can't hear the signal coming out of the headunit. Those dips you've measured may be there to compensate for the response of the speakers and their installation.

 

Wow I feel dumb after reading this post. What is cleansweep?

 

pics not working for me...

 

Yes. Exactly what "bluenoise" said. Could be intentional for many reasons tp compensate for driver attributes, placement and other factors.

 

Cleansweep is made for those of us who want to install aftermarket speakers and amps while trying to retain the stock HU. Here's a link to more detail.

http://www.jlaudio.com/press/CleanSweep05.html

 

Bluenoise,

You are correct that the EQ applied in the OEM system is designed to compensate for the response of the factory speakers within the car and to meet whatever sonic signature that the system designers wanted to achieve. If you plan to retain the factory speaker system, there is no point to a CleanSweep. The CleanSweep is intended as a starting point for an aftermarket amplifier and speaker system, not as an OEM system add-on.

The factory EQ that suits the factory speakers is not the same curve that you will need to optimize a good set of aftermarket speakers. The CleanSweep allows you to neutralize that factory curve and get you back to a neutral starting point (equivalent to an aftermarket head unit with its tone controls set flat). In most cases, this correction is enough to greatly improve the sound of an aftermarket speaker system without additional equalization. It makes a clear and beneficial difference with four of our XR 6.5-inch coaxials installed, for example. The midrange gets smoother and much more detailed. You could always add an EQ after the CleanSweep if you wanted/needed more tuning control, but it's not generally necessary.

Best regards,

Manville Smith
JL Audio, Inc.

 

Thanks guys for the info.

 

If I recall from the original thread, with Clean Sweep added you will lose 5.1 and the center speaker is not used except for HLF and Nav. In a 5.1 surround system your center speaker is your midrange. My question is: Was the before graph taking into consideration the center speaker or just the remaining 4 and sub that is used with the Clean Sweep? If the center speaker is not included in the graph that would explain the -3.5dB dip at the 1.3khz range. I don't claim to be an audiophile but, if freq response was that lame at 1 to 2khz range our audio systems would sound as full.

 

True, and good question.

 

Actually, the 5.1 protocol is five FULL-RANGE channels, plus an "LFE" (low-frequency effects) channel. The center channel is no more and no less of a midrange than any other channel. The response of the factory signal has nothing to do with 5.1... it's just a correction they applied to address the response of the factory speakers.

When a 5.1 channel system reproduces stereo material, it can operate only the left and right fronts or it can synthesize a center signal from the left and right plus surround signals. Most purists prefer the straight 2.0 reproduction to the synthesized fake 5.1 approach.

In practice, most home surround systems are set up in "small speaker" mode where the low bass (80 Hz and down) from each of the five channels is redirected and summed with the LFE channel to feed the ".1" subwoofer channel. This allows smaller satellite speakers to be used without overtaxing them.

In car applications, specifically the TL, there are serious compromises made. The dinky center speaker in the TL cannot operate full-range nor can it even get much below 300 Hz without overloading. So, the designers of the system filtered it to play midrange and up only. The left and right fronts and rears are more low-frequency capable and are filtered lower.

If you listen to stereo material (CD's or FM or XM) in the TL, there is no loss of anything if you turn off the center speaker... in fact, the stereo image improves. If you listen to a DVD-A 5.1 disc, it's a different story.

I am going to measure the center output of the head unit to see if it's full-range or band limited. I'm not sure if the filtering is being done at the head unit or at the amplifier. I'll report back to you guys when I find out.

Hope that answers your questions.

Best regards,

Manville Smith
JL Audio, Inc.

 

Manville,
Would you also be able to test the sub channel coming from the head unit to see if any filtering is going on there as well?
Thanks,
-Kris

 

Thanks Manville,

I told you I wasn't an audiophile. The reason I brought up the before graph testing procedure is because, the response curve between 900hz and 2khz looks more like filter notch than a normal response curve for a system of reasonable quality. I did test the center channel with a 2 channel source and you are correct the center channel has little effect in 2 channel stereo. My best guess at this point based on your very knowledgeable info and how my system sounds with a DVDA source is, that Acura ELS is tuned optimally to 5.1 with a midrange band pass to the center channel. To save money Acura compromises midrange for 2 channel stereo. I would think the best way to test this theory is to test the center channel response with a 5.1 source. Better yet, I wonder if we can get the freq response graphs from Acura?

 

Ah, that makes sense. Still, I'd be curious to see how the system as a whole looks on a frequency graph (speakers and all).

Thanks for the info.

 

I don't think Acura is trying to compromise any midrange in the left and right channels... they are simply EQ'ing each channel to suit their sonic goals and to correct for each speaker's response. The results of their work are less than stellar, but they were trying to improve things. What a lot of car makers are doing is using cheap speakers and then applyling DSP equalization to "fix" their response. It's cheaper to do this than to buy better speakers.

We are testing the center and subwoofer channels today. Will report our findings.

Best regards,

Manville Smith
JL Audio, Inc.

 

currently I have a 01 Honda civic with an aftermarket deck with 3 rca outputs......I have a 4 channel alpine amp (front and back rca inputs) for my mids and high's...and another mono single channel amp for my subs (which uses the sub-out rca)....that accounts for all 3 RCA outputs....

im gonna be moving this equipment over to the TL...now here's my question...

my aftermarket has front and back outputs and sub output...

this JL unit has only front and back outputs...

if I want to retain subwoofer control from the stock headunit on the TL how would I do this??? could I use the front output to control my 4ch amp (my amp allows for that set up) and and then connect the subwoofer line from the TL to the "rear" input on the JL unit and therefor use the rear output to connect the mono amp to control my subs...

my other option would be to connect my 4ch amp front and back RCA's, then connect my mono amp to my 4ch amp (the option is given to me with my amps), but then I would lose control of the subwoofer from the headunit...

I hope that made sense...I think it did....

basically right now in my civic I can control my front speakers and my rear speakers and my subwoofers from my deck independently....I dont care to have independent control of my front and rear speakers...what matter is that I can control my speakers in the cabin as a whole and my subwoofers seperately...

 

Your best option would be to connect your sub amp to the four-channel and to use a remote bass control knob (I assume your sub amp has such a capability).

Otherwise, you couldn't use the CleanSweep's master volume control to control the system volume, because the sub level would not vary with the CleanSweep volume. If you used the OEM volume only, you could do the first approach but you would lose the ability to use the CleanSweep's AUX input.

Best regards,

Manville Smith
JL Audio, Inc.

 

Just finished measuring the center and subwoofer signals in the TL...

LFE channel (subwoofer) signal is low-passed (not full-range)
Center channel signal is full-range and equalized.

This brings up the possibility of using two CleanSweeps with a special volume control adaptor so both will run off one volume knob (or maybe off the OEM volume). The only sticky issue is summing the subwoofer signal into the main signals... will have to do some further testing on that issue. Maybe we can keep the 5.1 functionality after all? Hmmm.

Manville Smith
JL Audio, Inc.

 

gotcha!

its ok with me, Im pretty sure that the Alpine has a sub/amp control I remember seeing it before, it actually allows me to change all my settings I got the V12 amp which is digital....so I guess I'll be going with one of these eventually...

also since you work for JL, and you obviously know your stuff...right now Im running two 10" type r's they are getting fed about 267 rms each (2ohm)...my amp is putting out 534rms at 2ohms....

I was thinking of getting rid of these two subs and going with a single 12" sub running 500rms...Im thinking of going over to JL for this....1 10" W7 OR 1 12" W6v2, either in a ported box....

right now my box is sealed, Im "happy" but not as "HAPPY" as I wanna be with my current setup...

so to sum it up:
Im feeding 267rms to each sub that is capable of running 300rms or a little higher.
I want to go to a single sub (perferably a 12") and feed it all my amp has to offer which is 534rms....

WHAT SHOULD I DO

any UNbaised suggestions LOL


J

 

The single 10W7 might be about the same output as the two 10's you presently have, if you have them in sealed boxes. If your 10's are ported, you will likely not experience an increase in output... but it will sound great.

The single 12W6v2 ported would probably be slightly louder and sound great.

 

Manville, Would there be any real benifit to mounting a 10w7 on the rearparcel shelf off the TL. Obviously to run in a sealed config that attempts to match the 12/db rolloff with cabin gain.

I really miss the sound of my 10w7, and I've just aboutt had it with the stock sub.


Nes

 

If you do a good job with the install, firing a woofer through the rear deck is usually the best approach in a sedan. You wouldn't mount the woofer to the rear deck, though. That would be a bad idea. Build a custom box with a sealing flange to the rear deck (allowing sufficient clearance for the forward throw of the woofer).

 

Manville, I am trying to design a system utilizing the full 5.1 surround, keeping all head unit functions operational. This would include the center channel and subwoofer level control.

My setup ideas so far:

XR-650 coaxial front and rear
Center unsure, need to research a bit more how much space I have and what I can fit
10W6v2 Subwoofer
300/4 Amplifier running front and rear
300/4 Amplifier running center and sub
CleanSweep running front and rear
CleanSweep running center and sub

Have you done frequency response graphs on the sub and center channel? Does the sub channel roll off in the same way as any of the other channels? (Front, rear or center) Can you post the graphs please?

Now for the application of the previous question. Lets assume that the sub and the center channel of the head unit have about the same frequency response within the subs range. Could I calibrate the subwoofer channel of the CleanSweep with the center channel output from the HU then reconnect the sub input?

Would the CleanSweep work calibrated like this? If power where disconnected for any reason does the CleanSweep retain its calibration?

Second main question, when using two CleanSweep’s can I just parallel the wires from the two volume controls together, and there for only use one control?

Thanks

 

5.1=garbage

 

?=explain

 

Hey, i just got a question.....

does the Stock 3rd gen TL's subwoofer run in an infinite baffle enclosure? If so, you probably couldn't run a W7 or W6, or any JL for that matter. only a free-air sub. again, i dunno if it is, but could you get back to me? thanks anyone.

 

I looked at the cleansweep the other day and decided to not get it because it doesnt have a output for subs. Why would JL build a device to clean up the signal comming out of a factory system and not put a sub out on it. You get a nice clean signal for everything but your subs. I guess Im a little too picky because i want all my amps and subs to get a nice clean signal.. I guess i'll wait for someone to come out with a single peice (with a sub out), so that my system will sound its best.

Peace!

J.

 

5.1 is for movies where you want to seem as if the action was happening around you. In music reproduction a soundstage can be accomplished in a home or car with TWO channels.

You want to sound as though you are sitting at a concert watching the lead singer front and center, with the winds and strings to his right and left and percussion behind him. If you have 5 channels it sounds like there are 5 lead singers who all have the same voice standing in front, to your left, right, and behind you not in harmony......in fact the audio information the speakers are reproducing is delayed and detracts from the clarity of music reproduction. I think the DVD-as would sound better in two channel rather than the stereo info just reengineered to sound as if it is recorded in surround which 99% of the time they are not.

just my .02

 

Why do you need a dedicated sub output? Let me know the plans for your system and I'll see if I can help....PM me if you want.
<------10 years car audio experience

 

And just when I thought I understood the Cleansweep....

So if there is no sub out put does that mean the signal to the sub is going to be all destorted and sound like crap? Somebody please expalin this as I will be doing my install within the next 2 weeks.

 

I wouldn't doubt that JL Audio is working on a new Cleansweep which will have AT LEAST a sub input/output if not a center channel input/output as well. More and more stock head units have subwoofer output, and several now have center channels.

 

kyle-wdp, my system is pretty much done (check my sig). I have been messing around with car audio for a while also. My beef with the cleansweep is that it is meant to clean up the signal that goes into your aftermarket amps. Well most people that upgrade their sub go to a aftermarket amp. Most old school people that used to run class AB amps and then went to class D amps for their subs know that class D amps arent as clean. If there was a way to clean the signal before amplification i would like to look into that device. I thought the cleansweep was that device. Why dont we get a cleaned up signal to run to our sub amps?? Yes you can use a knock down to get the signal to the amp or purchase another peice of equipment all together... I dont want to do that. If im gonna spend $300 (on sale) on a peice of equipment, i would like it to do what it is advertised to do.

 

Manville,

During your testing, did you verify that the front and rear channels are full range to the speakers, or is all low frequency routed the the sub. Are the crossovers done in the OEM head unit or the OEM amp? This would help me decide where to get the singnal for the Cleansweep. I have not seen an ideal solution to run amps for the center and sub with the Cleansweep yet.

Thanks,
JJH1234

 

Think about this way, you are in middle of the band. Drums and stuff are behind you, vocal is front of you. You could be one of player. I think it sounds great especially Shania Twain and 3 doors down discs.

 

Think about the fact that most big concerts these days have monitors spread throughout the venue, mixing vocals and instruments to come from all directions, that's when the TL matches a live show using the 5.1 DVD-A sound system.

 

kyle-wdp

I agree with you on many points regarding the multisound trickery that some music producers have attempted with multichannel recordings in the past. Music is not film and does not need to have the singer's vocals going around each speaker in circles. I do believe that 5.1 have its place if done right.

In the studio the artist is in a controlled environment. Everything is and can be controlled by the sound engineer and the artist. Done right 5.1 can bring into the artist's studio. You are sitting inside the studio with the artist and sharing his or her vision of what the music should sound like. Imagine sitting in the studio as the Eagles recorded Hotel California. Each musician is sitting around you and playing their own instruments. You no longer are a just front and center but on the stage. I know these days with multitrack recording tech most bands are not in the studio at the same time but to have the ability to bring them together with 5.1 is great. Many within the music community have embraced multichannel sound for this reason. Many artists such as ZZ Top, Talking Heads, Blueman group and Joe Perry of Aerosmith pushing for the success of DVD-Audio. The second and the one that appeals to me more is the high defition of the music. I can hear the instruments clearly and distinctly. It's like regular TV and High Definition TV. Consider DVD-Audio the High Definition standard of sound.

In a live environment the artist is at the mercy of the concert hall and its acoustic effects. Done right 5.1 can make you feel as if you are there, with the echoes of each hall and the crowd going crazy.

The key is it must be done correctly to make it sound real.

I love the 5.1 feature of the TL and find myself going back to my DVD-Audio disc regularly Any upgrades I do must retain the 5.1 option. I would be the first in line to buy the cleasweep if it had been done for 5.1 .

BTW I have it in my home audio as well. I own both SACD and DVD-Audio discs.

 

Am I the only one who thinks JL Audio is probably working on a 5.1 version of the Cleansweep. It would make sense as more and more OEM head units have some type of surround (Pro Logic/Pro Logic II, DVD-A, DTS) built in...

 

I doubt it......the largest JL audio retailer in my area has sold only two cleansweeps. They are a car audio specialty store and get a lot of dealership business. I think the cleansweep we have will be around for a while. I would love to see them add more preamp style features like a sub out with a selectable slope crossover (6,12,24 db/octave) and maybe even a chip style in and out fully adjustable crossover a la kicker amps.

As far as the 5.1 goes to each his own. It is definetly neat on the one track where you can hear a laugh or cough behind you or to your right.....
as for me I don't miss it- that's all. I love my semi-stage.