Attempting 850 speaker replacement.

[Alecw81]

Since it seems like you're already spending a great deal of money, why not just order the Dynaudio from Volvo?

[kcodyjr]

Hasn't been as pricey as you'd think, yet, remember I'm doing two cars at once.

That said, I'm not aware of a Dynaudio package for the 850, only for the S70/V70.

[kcjones]

Billfitzmaurice.com speaker designs are incredibly amazing. I work with a lot of pro audio and this is the stuff. The auto-tuba, aptly named for being a folded horn/tuba design for use in cars, uses an 8" or 10" highly efficient long throw woofer and a compact folded horn design for super smooth bass. I plan on building mine this summer. I have built the T-39 for my band and this single 12" sub puts out STUPID amounts of ultra-clean, undistorted SPL, with a 200w amp. Sorry to advertise, but Bill knows his stuff.

Also, parts-express.com sells inline crossovers for pretty darn cheap compared to most car audio outfitters.

Let me know how the grills turn out. I was smacking the crap outta mine with the speaker surround and ended up ruining one

[kcodyjr]

Thanks for the tip on crossovers, and surely I will let you know once I've got a grille on. Seems no point in trying them over the OEM's, crap through a veil of silk sounds about the same as crap through a bale of hay.

As to the sub, though, that's more space than I really wanted to give up. That's a very interesting design if I did, though word is, the 850 sedans and S70's have a pretty heavily insulated rear seat back. That was the driving reason for considering a surface-mounted free air sub.

Putting an eye on that autotuba; and especially as hypothetically paired with those Pioneers, I'd certainly cut them off at 40Hz to avoid possible phase mismatch issues with the door and deck. I'd rate its effective response range as 25-40 with damn respectable flatness. I'd cut off the sealed design at the same 40Hz for the same reason, but it'll be notably more efficient towards the top there, but then it falls off with relative grace all the way to 20Hz, and presumably below. The sealed design also scales upwards of 40Hz more smoothly, making it a better match to smaller midbass drivers.

The autotube, thus, strikes me as more of the precision instrument; best available within its designated range (25-40Hz) but unsatisfactory outside of there. That makes it part of a separate treatment of each frequency band - the hallmark of the highest end designs, but bulky and expensive - too much so for me. The guys' pro audio roots are plain to see, for sure, but notice he's showcasing the sub in a van.

I've always been a fan of flat response designs, which of course rules out bandpass and most bass-reflex designs. Waveguides are a possibility if I want to convert the entire trunk. But really, the most precise is the infinite baffle.

This is much more about full coverage frequency response than about SPL levels. It only has to be loud enough to drown out the wind at 85mph with all four windows down and the sunroof wide open, and not give me a reason to fiddle with the bass/treble and fader controls.

[kcjones]

Agreed!

Infinite baffle will wield better "flatness" but you are gonna need some serious power.....

Also note that all audio suppliers, regardless of whom, apply smoothing to their charts. This is an industry standard I'd love to abolish

I'll be sure to post charts, pics, etc when I get mine built. Right now I have a home theater sub and a power inverter jammed behind my driver seat! It's not great by any means, but it does soothe away road rage with its built in back massage ability

[kcodyjr]

I've found the most superior tool for soothing away road rage, is my 97 850's loud pedal.

It helps that the secondary result is the knucklehead disappearing in the rear view mirror.

I'm not believing the smooth charts either; in fact I haven't seen any yet. For the Pioneers, I'm going on the advertised feature of having a flat tonal response from octave to octave - if that's outright bull they're going back, but close will be close enough at about $120 per pair including shipping.

As for power, let's start by dismissing the wagon. It's going to get one of those powered spare tire jobs, already has the OE 4x40 amp and SC-815 head unit, and that's about as good as a grocery getter has any right getting.

So, constraining to an 8" because I think that's what will fit and dual coil, and being clever with the amp: I believe I saw someone had come up with an amp of class D construction with class A response characteristics - I'll have to look again. The key is small enough to also hide under-shelf, big enough to power that 8", but 4 channel and flexible enough to also drive the rear deck effectively.

This would be to eliminate the parallel drivers that ordinarily turn 2x8 into 4 ohm, leaving just the new 4 ohm door speakers and a negligible transistor input being driven off the rear factory harness. I'm not going to run RCA; both to keep factory head unit compatibility, to be a purist about not playing with the audio harness, and because the difference is well below the noise floor of a moving car. I'll get connectors from a junkyard to intercept the rear deck wires. I'll scotch-connector into the antenna wiring for turn-on signal - on the antenna side of the disconnect.

Then, adding a 4x40 OE amp would cover the doors (actually the new amp would slave off that via factory harness) and the dash tweets driven directly by the head unit, thus, each amp circuit still sees 4 ohm. This would require no cutting into the harness at all - by offloading, not by rewiring.

Sanity check a moment; I'm not going to even think about amps and subs until I'm satisfied with the speaker job.

[kcjones]

You're on it!!!

The "smoothing" I was referring to comes about like so:

Companies do an analysis (1W-1M) to give sensitivity (SPL) charts. NO speaker can put out those fancy lines you see. They all apply a certain amount of smoothing to illustrate "basic" responses of the driver. So, even though it looks like a nice, clean curve between say, 50 and 70 Hz, there can be a spike or drop, severe even, around 60Hz that they have managed to "erase". Pro audio world helps part of this. Most drivers/pre-built boxes come with a set of "instructions" telling where to cut or boost certain frequencies to tune the speaker "flat". Flat frequency response doesn't necessarily mean a straight line across all frequency bands @ 90dB. Industry standard claims that flat is anything that doesn't fluctuate a full 10dB+/-

[kcodyjr]

Indeed. If I want "truly" flat, I'll have to start thinking about building a car PC based head unit, so I can apply detailed equalization in software. The goal at the moment is just to get as close as possible by throwing parts at it. I could spend a million dollars putting together the perfect setup on the bench, and it'll be off kilter as soon as it's in the car.

Realistically, that kind of precision only matters when you're sitting still watching a high def Pavarotti recording.

I don't want to go that far because the goal is to get a simple, good sounding system that I can operate literally blind - rather, with my eyes glued to the road. That rules out a touch screen. I'd have to go with a full set of aftermarket amps to accommodate an off-the-shelf multiband parametric EQ, which violates the constraint I set at the beginning to avoid irreversible changes to the vehicle wiring harness.

[Red-Arrow]

You're on it!!!

The "smoothing" I was referring to comes about like so:

Companies do an analysis (1W-1M) to give sensitivity (SPL) charts. NO speaker can put out those fancy lines you see. They all apply a certain amount of smoothing to illustrate "basic" responses of the driver. So, even though it looks like a nice, clean curve between say, 50 and 70 Hz, there can be a spike or drop, severe even, around 60Hz that they have managed to "erase". Pro audio world helps part of this.-

I agree with this poster. The frequency response Charts posted on speakers are totally baloney, its always a nice smooth frequency response with amazing HF detail and very lose bass sensitivity. How stupid do they think we are anyway.

The problem with most coaxial speaker is you get tweeter waveform distortion from the woofer cone excursion. Tannoy used a Metal tulip cone around the tweeter to help the wave from the cone slip by the outside of the tweeter. You get better symmetry but worse time alignment. The other problem was tweeters need powerful magnet systems in order to produce linear movement, we thing only woofers need strong magnets. Almost no high end speaker company use the small neodymium in their high end tweeters, not Dynaudio, Linn, ScanSpeak, Vifa. ATC ( soft dome midrange) or anybody else I can think off. I'm a big believer in separating the tweeter from the dive unit and time aligning it.


I recently bought someClarion SRR1386 speakers and according to Clarion they are the best ones the make. I was totally disappointed in the bass response. Tinny and shallow are two words that came to mind right away. The tweeter was over bright and harsh at times. The midrange was over shouty and hard.

The frequency response chart is complete fiction, bass response down to 40Hz and HF reproduction up to 100Khz! what a pile of crap! I know Clarion made some good products in the 90's but it seems like they make poor quality products now.

I would hold on to my original bass units if I were you because you will lose a great deal of low end information. I honestly hope your Pioneers work out better for you than the Clarions did for me. Let me know how the Pioneers fair in your Volvo.

[kcodyjr]

I checked that Clarion out. I'm reading that frequency response chart as 140Hz-35KHz +/- 10dB, or 160Hz-30KHz +/- 5dB.

Honestly, that chart sucks for a woofer, but isn't terrible for a 2-way mid/tweet. If this is their idea of hamming it up to make it look good, they're doing it wrong.

That Clarion has the tweet sitting fairly low, the Pioneers I've chosen have the tweeter mounted on a center stalk, and should give pretty good excursion before colliding.

I understand and share your skepticism, I'm planning to do in-car side-by-side testing before delivering a verdict.