Audio project complete! REVIEW MusicarNW Portland,OR

[VP Electricity]

I think the Hybrid Ovation are a big step up from the Dotech (remember, I put H.O. in my own car, so I am not a totally disinterested bystander).

H.O. XO point, 1800 - Dotech XO 3200. This means that between 3200 and 1800, the H.O. set has better off axis dispersion. (In a car with lower 4" locations or with more mid-tweeter distance, this would be an even bigger advantage than it is in the BMWs).

H.O. tweeter resonance 900, Dotech unknown (I could test if I get really motivated, but the higher XO point tells us that the Dotech is not as mechanically robust as the H.O. MT23.) Sound on the tweeter is definitely smoother and warmer.

H.O. 100mm woofer uses neodymium rather than straight normal magnet alloys, allows shallow profile with more powerful magnet than Dotech.

Cone of H.O. mid is closer to Elate poly laminate (Dotech uses poly/fiber laminate).

However, the Dotech MSRP is $550, the H.O. 4 is $850, so as a reference, that's like 55% more.

Nothing wrong with Dotech - and I likes me H.Os

[VP Electricity]

Re-tuned Mineo's car after the speakers broke in... the on-axis Dotech tweeter had smoothed out a lot after a few hours of playing, and I was able to bring 10K on the EQ back up to flat and get some detail and sparkle on the top end.

Also re-calibrated the front end of the 360 and got some more drive out of it. Let me lower the noise floor and drop the amp gain. Sounds even better.

[VP Electricity]

OK, I know he SAID it was done...

So we still had some intermittent RPM-related noise in the car. Rockford tech support blamed the 360.1, version 1, told us we needed a version 2. Version 2 had a "ground-lift jumper" added for persistent noise problems. Well as it turns out, for complex reasons, I wasn't going to get a 360.1 V2 back from Rockford, it will be unavailable for a while and the .2 will be the only unit available per Rockford (it is the only one that sells anyway).

So, I gave Mineo a refund on the 360.1 and gave him a deal on an upgrade he had been asking about - a Zapco DC650.6 6-channel amp.

- 50w to the Dotechs, active crossover filtered instead of passive on the bottom end of the 4" range

- 50W to the underseat ADMW9, again active filtered rather than passive (a big gain since a low-pass crossover filter in that region (150) requires a big series inductor and associated insertion losses)

- 360W to the single 4ohm 10"

Now, one of the biggest shortcomings of the DC650.6 is the lack of a plug-in bass knob. We used the external SLB-U line driver and the plug-in level knob to control the bass level. It went where the 360.1 knob went, but we needed a new bezel (the 360.1 knob had an LED that required a second hole in the panel). Tom made one out of black plexi, flushed into the panel. Not sure how the pics will come out, will post later this weekend. Hard to take pics of a black plexi bezel in a black car sometimes. It looks really great in person.

The Zapco has parametric EQ. This is a more sophisticated EQ than most, in that you can adjust:

- The note you are emphasizing or attenuating ("center frequency")

- The aspect ratio of the "bump" or "dip" you are creating - how many notes on each side of the center frequency you are also affecting

- Finally, the amount of emphasis (boost) or attenuation (cut) at the center frequency

Most EQ only let you adjust the last one, and the first two are predefined for you. That's a graphic EQ. Many folks prefer those because they are simpler, but hey, we have BMWs, simplicity isn't for us

The Zapco also has time alignment in its internal DSP. We are delaying the R channel and the L channel by different amounts to compensate for the off-center driver position, and also to make the sound from the sub arrive at the same time. We are cutting the L channel by a fraction in loudness to compensate for distance attenuation.

The DSP has lossless active crossover filters that can be set to 24dB - far steeper than most passive crossover filters are (if they are, they are far from lossless, and cause a lot of insertion power loss as well as being very large and costly). So we are playing the 4" with a 24dB highpass filter, for instance.

Here are the changes:

1) The engine noise is gone. No noted recurrence. System background is darker, quieter, no hiss or audible noise floor.

2) Higher image. EQ helped elevate the image, and driving the midbass on separate channels let us get the midbass sounding higher too, with EQ and level settings.

3) More bass up front, due to the ADMW9 playing lower.

4) A little less volume. There is less loudness, but I don't feel like I'm done tuning this setup. I think I can get some more loudness.

5) After tuning, the gong was not a factor. The recoding attempt yesterday (to reduce gong output by recoding the Pro HU to "HiFi mode") was a fail, the UK Autologic folks had gone home, and while CIP59 did support the car more than CIP58, it still wasn't showing me the screens that I expected. I will talk to them next week. I'm sure it is possible but at the moment I didn't have that option available. I think it will sound better if we recode because the HU should get 5 clicks more of available output without clipping. IF ANYONE IS DOING AN INSTALL REQUIRING RECODING, I STRONGLY RECOMMEND SCHEDULING THE PROCEDURE DURING AUTOLOGIC UK WORKING HOURS.

6) Did I mention the gong is livable? I should caution that this was after tuning, and is not due to simply product used - it is definitely a side effect of tuning.

In non-sonic news, Tom has figured out how to dye standard trunk liner material to match the 1-series trunk liner almost perfectly, so the fabric and the color look great. Will post pics of this also.

The amp fits under the previous cover with some mods.

Another forum member stopped by and saw and heard it - maybe he will chime in (Mineo is out of town this weekend, but I suspect he will be around Sunday night or early next week : )

[Jalisco]

Musicarnw did an awesome job on the install looks great, and the audio is top notch.

[wkndracr]

looks great! I recently installed a set of Morel MW 224 9" that i found on ebay under each seat in a similar fashion, and am awaiting a set of the same Dotech Ovation comps, powered by my trusty Soundstream Reference 705s. Next is to add an Alpine PXE-H660 processor (instead of the cheapo Line out converters i have now) and build a fiberglass sub enclosure for the corner of the trunk (should be interesting as I have limited experience with fiberglass). Can't wait to have good sound again!

VP Electricity, I like your style, and it sounds like you're a true audiophile. I work as an installer as well, and most of the installers I come across would have no idea what you're talking about. I just wish my shop would get into more high end products so I have some nice stuff to play with. (I had to get the Morels on my own, lol!)

[VP Electricity]

Thanks for the kind words.

Is your car base audio or Logic 7? Either way, there are a couple of paths I'd consider over the 660, based on many folks' experience with it and the 650 (I know the setup is improved on the 660, but the principle is the same).

Are you running the Dotechs active or using the passive xovers? I would run the Dotechs -3dB on the tweeter output, and they will change how they sound after 2-3 hours of playing (mostly tweeter).

I assume your Reference is an old-school SS and they haven't mimicked the old-school stuff under the new owners? Those have common-ground inputs as I recall...any RPM noise?

[wkndracr]

I have the base non-amplified system. The amp is a true vintage SS that I bought used about 7 years ago. I have it in three way mode, running the 9's on the rear channels, and the Morel comps with the included crossover on the other front channels. I'm using the active crossover to filter highs and lows from the 9s, as well as a high pass for the 4" comps.

What did you have in mind instead of the Alpine unit? I really like the auto eq and time alignment features, and the price is right. I also like the Audison Bitone, but it's a little more than I want to spend on a processor.

I have no engine whine, bit I do have this odd buzzing/distortion sound from the tweets but only during certain types of music, like when there is heavy bass and highs, but little mid (hard to explain). I'm thinking it is my crappy high to low converter, but I tried bypassing it, running speaker outs directly to the amp just to check, and the noise is still there. Very annoying. I'll try temporarily hooking up a headunit to see if it goes away.

[mineo77]

Originally Posted by wkndracr

but I do have this odd buzzing/distortion sound from the tweets but only during certain types of music, like when there is heavy bass and highs, but little mid (hard to explain).

ha, does this sound familar VP? I think we worked that out about 90%, but there is still a hint of that funny buzz/distortion in a variety of music that i listen to. Mainly when there is bass with some high freq going on at the same time. I would say that VP has almost completely solved it for me. I will leave up the explanation to him since i have no idea what he was doing when he was making adjustments.

[wkndracr]

That's too funny! At least I'm not the only one. Hopefully I'll be able to work it out as well

[mineo77]

Originally Posted by wkndracr

That's too funny! At least I'm not the only one. Hopefully I'll be able to work it out as well

well i will keep you updated. i didnt have the heart to tell Ken (VP) today when i saw him since he has put SO much time in my car...but once he opens his shop and we retrofit usb/ipod/bluetooth i will have him check it out again and i am very confident we will nail it. As i mentioned before, he did tweak some things a few weeks ago and has nearly eliminated the noise. just takes time listening to a variety of music under different conditions to start learning your system as you are well aware of so i am not worried. The last tweaking of the system he did was f'n amazing. It sounds so solid...the guy is really gifted in this audio world.

[VP Electricity]

I don't know for certain, but they sounded like two different kinds of noise.

I'm guessing that the one we messed with today is a grounding issue, and that I need to move the Zapco SLDIN.BTL ground to a better location relative to the amp ground (or the HU ground - in the worst cases, that gnd wire needs to be grounded to the HU chassis, but I've never had to do it).

The 1-series is SUCH an electrically noisy car. It takes the title from the E53 X5, the former worst bad actor for EMI.

[wkndracr]

hmmm... I'll maybe try swapping tweeters, just for the heck of it to see if the noise is still there. Hey Ken, what were those other options besides the PXE-H660?

[mineo77]

Originally Posted by wkndracr

hmmm... I'll maybe try swapping tweeters, just for the heck of it to see if the noise is still there. Hey Ken, what were those other options besides the PXE-H660?

fyi...i had Hertz tweets in first that did the same noise. swapped tweats to the morel we tweaked and the sound went away. replaced my amp for a zapco and the sound came back. i think it has much more to do with how you tune the system and level your amp...maybe??

[wkndracr]

I was doing some fiddling today and I think the noise is coming from the oem headunit, in the middle of the volume range (cant tell if its there at the top of the volume range or not). I temporarily connected my old Pioneer to my amp and the noise was gone! So now i guess ill have to install an aftermarket radio, which I didnt want to do, since the oem bluetooth works so much better than the one in my Pioneer. I have a plan though, to keep the oem radio for BT and chimes while still having an aftermarket headunit for music. And I thought having the base audio system was going to make upgrades easy!

[VP Electricity]

Whoa whoa whoa.

Before jumping to conclusions...

I was not aware that Soundstreams used balanced inputs. What is the output of your HU connected to? The Soundstream RCAs input connectors?

I suspect you are feeding balanced outputs into a non-balanced input.

[wkndracr]

you are correct. The permanent setup right now is using a LOC from the factory HU to the amp, but i did try sending the balanced outputs to the unbalanced inputs, bypassing the LOC, just to test. I had to use a ground loop isolator to keep it from clipping. I know, not really the proper way to do it, but I just wanted to see if anything changed. The sound coming out with my Pioneer HU connected was so much better, it now makes me want to go back to my original plan of installing an aftermarket HU, but I really wanted to keep everything looking stock. Maybe a processor that would let me keep the HU at one volume level out of the noise range would do the trick (Audison Bitone?)

[mineo77]

i would suggest looking into reprogramming your stock HU to Hifi...so it knows it has an external amp and you would have a good flat signal from the HU. Ken's been talking about this for awhile, we just havent done it. I think this could be a key part and some of the idiosyncrasies from our 1 series projects with the standard radio/audio....?

[VP Electricity]

I thinl your LOC gets more blame.

If you're interested in trying something, PM me your mailing addy, I will send you something to try out in place of your LOC.

LOCs have two big functions - attenuation of the AC signal, and isolation of DC. The first is done with resistors, the second with transformers like those in a GLI. The transformers also can pick up EMI out of the air, the resistors hurt the noise floor, and most LOCs add distortion and limit freq response too.

I don't think it's "coming" from your HU per se. I do think an amp change could also solve the problem, but first let's try this item if you like.

[mineo77]

Originally Posted by VP Electricity

I thinl your LOC gets more blame.

If you're interested in trying something, PM me your mailing addy, I will send you something to try out in place of your LOC.

LOCs have two big functions - attenuation of the AC signal, and isolation of DC. The first is done with resistors, the second with transformers like those in a GLI. The transformers also can pick up EMI out of the air, the resistors hurt the noise floor, and most LOCs add distortion and limit freq response too.

I don't think it's "coming" from your HU per se. I do think an amp change could also solve the problem, but first let's try this item if you like.

yep...thats what i was trying to say! hahahahaha (sarcastic)

[wkndracr]

I was figuring it had something to do with the LOC, thats why I tried to bypass it, albeit not really the right way. I did hear the same noise out of the rears today with nothing connected at all to the front channels (my rears are still wired like factory to the oem HU). Maybe I have a bad HU? Or maybe its just the HU puts out distortion past say 2/3 to 3/4 volume that I'm now amplifying so its more noticeable. I'll PM you, VP, so as not to clutter up this thread even more

[mineo77]

Here are some recent shots of some of the work MusicarNW (VP Electricity) did. You will notice the new amp and new sub knob.

Stealth sub knob which is retractable


Morel tweets and 4"


Custom trunk liner, painted to match carpet


Removal compartment of the trunk liner to access battery and storage


Zapco Amp installed


Full trunk shot with liner removed






Nice and clean install...sounds freakin amazing.

[Tumo135]

That setup is awesome. That carpet matches great. Does anybody know where i can get it?