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Inspired by a question asked on the other side by someone who is now registered on here too and by the lack of bass on my system. OK, so I've got the original LR speakers rather than the HK ones but need to swap the 6.5" woofers in all 4 doors at the very least. I've got an aftermarket Kenwood DSP head unit driving the original speakers. Well, nearly original as I changed my basic spec door panels for ones from a higher spec car and found that as well as the wood on the outside, they had a pair of HK midrange speakers still bolted to them. So I've got bog standard woofers and tweeters but HK midrange at the moment. A professional sound engineer spent a good 2 hours while we were driving through Holland playing with the settings and got it as good as it can get but the woofers are decidedly lacking in the bass department (and there's no sub). As I've got OldShep's 2001 Vogue here with a working HK DSP system in it, I bunged a CD in the changer expecting amazing sound quality. No matter how I fiddle with the settings, it's good but nothing like as good as I expected it to be. In fact, it's not that much better than what I have. Maybe I've been spoilt recently with listening to the Bose system in an Audio RS7 and the Naim system in a Bentley but I don't see why it shouldn't be possible to at least get close.

So, I need to change the speakers. They need to be 4 Ohm, with as low a frequency response as I can find and not stupidly expensive. I'll probably need to add crossovers too. Most 6.5" speakers are 2 and 3 way coaxial but that isn't needed and so far I've narrowed it down to http://www.ebay.co.uk/itm/2x-Skytec-6-5-Hi-Fi-Polypropylene-PP-Mid-Woofer-Bass-Speaker-Driver-Cone-200W-/182455996924 (nice low frequency response but 8 Ohm so no idea how they would interact with the HK mid-range and standard tweeters I've got in there and I've never heard of Skytec), these http://www.ebay.co.uk/itm/JBL-300W-TOTAL-2WAY-6-5-INCH-16-5cm-CAR-DOOR-2WAY-COMPONENT-SPEAKERS-TWEETERS-/190885731881 (A name everyone has heard of, 4 Ohm but frequency response only down to 50Hz although they do come with a pair of tweeters, which I don't need, and a pair of crossovers but are described as mid-range) or these http://www.ebay.co.uk/itm/Bass-Face-6-5-Inch-16-5cm-165mm-800w-Mid-Bass-Drivers-Car-Door-Sub-Speakers/351990186243 (which seem to meet the spec but are just for the speakers so crossovers would need to be bought separately). My head unit also has an output for a sub so I will probably add one of them too.

Anyone tried any of these or got any other suggestions?

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Are the stock speakers receiving the whole frequency range or is there a crossover built in somewhere?

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No, no crossover, just 2.2uF capacitors in series with the mid range and tweeters so the woofer receives the full range.

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I think the woofer in the stock system get somewhat of a filtered output... I haven't actually measured the frequency response from each channel on the amps, but the door amps (and DSP on the later systems) have different outputs for the woofer and mid range speakers, which to me says that they are internally filtered in the amp.

The tweeter has it's capacitor in line to filter the mid frequency range out, as it isn't driven of a separate channel aswell, but off the mid/hi output.

In fact, I had a door amp set up on the work bench, testing an unbalanced - balanced line level converter, and I connected up a woofer and a mid speaker to the 2 amp outputs and the woofer definitely doesn't get a full range to it.

So there isn't an external crossover in the vehicle wiring, but I am assuming that the door amps (or DSP amp) filters the frequency bands for each speaker being driven and then amplifies them separately.

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What door amps? Nothing fancy like that on mine, just bits of wire back to the head unit.

Mine started off with the low line speaker install, woofer and tweeter in the front doors and woofer only in the rear (section E6, page 4 of the 1997 ETM in RAVE). I connected the midrange (and fitted the cap) when I changed the door trims so have bought it up to mid line spec (section E6, pages 6 and 7 of the 1997 ETM in RAVE) albeit with HK midrange speakers. So I've got no door amps, just speakers driven directly from the 4 x 50W DSP output from my Kenwood head unit. The Kenwood also has outputs for a sub so I may add an underseat sub (something like this http://www.ebay.co.uk/itm/MBQ-Car-Underseat-Compact-Slim-Active-Amplified-Amp-Subwoofer-Dual-Voice-Coil-/252690944978) which will fit under the rear shelf where the factory one would have been if it ever had one, but won't take up all the space. All I'll need to do is run a pair of coax cables and power from the head unit to the rear.

The intention is to replace the speakers in the doors first. If I find something that sounds decent and gives a bit of bass, I may not need to add a sub but if I can't feel the bass on the door skins, then that will be added later.

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I keep forgetting you have the poverty spec.

I'm pretty sure the later ones without amplifiers have a 'little black box' crossover unit in the doors (well, it appears so from a picture Sloth send me of the wiring of his parent's one)

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jbl's will be a better speaker by far and 50hz won't be as boomy in the door.

Is the sub out a dedicated frequency or can you sweep it? I'd have the sub at around 60hz where the mid-range is going to start dropping off. Set a cd going and sweep the sub range until it evens out the sound.

'twill make for a far more even sound with the addition of a sub.

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Not according to RAVE, low line and mid line all had the speakers driven directly from the head unit no matter what the year. High line had individual door and sub amps until they started fitting the DSP unit. Maybe someone has tried to improve the sound on Sloth's parents car? With it's cost and infamous unreliability, I reckon the DSP is the one to steer clear of personally. In a car with low line, mid line and early high line, it's possible to fit a modern head unit with, at worst, the addition of the attenuators. If you've got the DSP system then you are restricted to fitting a Grom or Pure DAB unit, both of which cost as much as a decent head unit alone, and retaining the original head unit. That's fine until the DSP amp turns up it's toes then you'd need to fit one of your units using door amps or spend a stupid amount of money on a new DSP amp.

I can understand people wanting to keep the car looking original but having driven OldShep's car and been keen to see what this fabled DSP system sounded like and in my view it's a bit lacking in performance. As for the head unit, FM radio, CD or cassette. Hmm, there's nothing that is going to demonstrate the sound quality on FM, I haven't seen a cassette in years (I've probably got some somewhere but have no idea where and the sound quality from them was never much cop at the best of times) so it had to be a poke around in the boot and load a CD. A Grom adds USB and Bluetooth, while the Pure unit gives DAB as well but for £150 I've got FM radio, DAB radio, 2 x USB (one front one rear), aux in, a CD player that can play discs burned in MP3 format (so around 10 hours to a CD) and Bluetooth connectivity including handsfree calling for the phone. OK, it may not look original but doesn't look too out of place and with the right speakers, It'll sound good too. I just need to find out what speakers to go for.

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I'm leaning towards the JBL's too, at least they are made by a company with a reputation even if they are the most expensive of the lot. The sub out on the head unit has a low pass filter that can be adjusted between 30 and 250 Hz, while the main speaker output has a high pass filter that can be set over the same range so a crossover threshold can be set.

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what's the range of the tweeters?

Would band pass on the mid-range be a bit overkill for what you want do do?

I used to find alot of gear around 2.5k was a bit pokey and harsh and needed taking out on the graphic to even the sound. JBL stuff was alot better tho. 2441's were always one of my favourite drivers.

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My parent's car has all three speakers as standard - tweeter, midrange and woofers in the front, midrange and woofers in the rear. But no amplifiers bar head unit of any kind. The additional inline filter 'thing' looks factory.

It is an actual Bordeaux though, so it may be unique to that run.

I'd avoid the Skytec stuff - if they're amplified and non amplified wall mounted speakers are anything to go by. Cheap and has its place, but not if you're looking for quality sound.

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blueplasticsoulman wrote:

what's the range of the tweeters?

No idea on the standard ones but for the JBL's they quote 50Hz - 20kHz for the pair. I'd try swapping in the JBL tweeters to see if they sounded any better than the standard ones. I'd assume the woofer goes up to about 5kHz with the tweeter doing the top end. All this audio stuff is a bit low frequency for me, I'm used to dealing in frequencies in MHz and GHz rather than something getting dangerously close to DC as far as I'm concerned.
blueplasticsoulman wrote:

Would band pass on the mid-range be a bit overkill for what you want do do?

There's no band pass other than the 2.2uF cap in series with the mid range speakers. The head unit has a 9 way graphic with +-12dB on each band (as well as all the DSP settings) but supplies the standard full range output per channel (F & R left, F & R right). The high pass filter on the speaker output can be set for anything between 30 to 250 Hz while the sub output has a low pass filter that can be set over the same range. So I could set it so anything below 50Hz is only sent to a sub and everything above goes to the rest. Presumably, I'd need to give some overlap? Set the sub for everything below 80Hz for instance with everything above 50Hz going to the rest of the speakers? I think I'd probably need another road trip across Europe with my tame sound engineer in the passenger seat to set it up. Fortunately it does also have a save setup feature so if you ever disconnect the power you can recall it and put it back as it was (however, it doesn't save the stored radio stations, display colour, Bluetooth pairings, source select method, etc) .....

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Why not get the JBLs and fit the whole set? I don't see any reason to keep the stock tweeters if you're going to replace the mids. I've used JBL (Well, Infinity, but they're the same company) before and they sound good. Then again, I think the DSP amp setup sounds pretty good :)

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dsp sounds good in mine in my opinion. sub on 4, bass on 6, and treble on 3.

I used to have the sub on 7 but then the Mrs put radio 1 on once. I couldn't be doing with it.

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I'm going to go for the JBL's but the only reason I'm considering not using the tweeters is that, according to the JBL website, they are larger diameter than the stock ones so might need a bit of butchery to get to fit in the housing. However, in saying that, the ones on eBay are the 600C while the website only gives data for the 600CE so it may be that the eBay ones are a superseded model and are slightly different. I'll find out in the next couple of days when they arrive.

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blueplasticsoulman wrote:

dsp sounds good in mine in my opinion. sub on 4, bass on 6, and treble on 3.

I used to have the sub on 7 but then the Mrs put radio 1 on once. I couldn't be doing with it.

I tried a bit of Alterbridge (Blackbird) but even with the sub on 8 it hadn't got the grunt, or the top end for that matter, that I get on my home system (NAD amp and CD deck, Dual (better known for turntables) speakers) with all tone controls flat and sounded not much better than my existing standard speakers. When you do the sort of mileages I do, often at night on my own, a bit of decent quality makes all the difference, especially when you know how good a system can sound.

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have you thought about dual concentric?

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Yes but why? As I've got separate mid range and tweeters, it's only the woofers that I really need (or ones that produce a bit more bass than the ones that are in there). Too late now, the JBL's are on order and will be here by Wednesday.....

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ah ok. just you said about considering not using the tweeters.

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I meant not using the JBL ones that come in the kit and just keeping the original ones. From the spec the JBL ones look to be a larger diameter so I'm not sure if they will fit inside the housings. It might just be the plastic surrounds though so I could cut them off and they might fit. I suspect the JBL's will sound better though but I'll try hanging them in temproarily first before getting involved in serious butchery and glue.