Advice please on upgrading stereo

Hi all,

I have an 06 2.0 NC
The speakers are frankly not up to the job, I would like decent ones in so that if roof down…which is is pretty much all the time I can listen to “stuff”

What would I require in the way of speakers?
I would also like them behind head
Do I need to replace head unit for better sound or will the speakers be enough?


Speakers are usually the biggest improvement. Do you have a Bose system? If not, a set of good 5x7" would be your best bet. Preferably a component set so you can put a tweeter on the spot where the stock one is now. Coaxial would be easiest though. I have seen 5x7 component sets but they are not abundant. Another option which requires minor plastic cutting is an 8" component set. The inner door panels contain a line where you have to cut for an 8" opening (the optional Bose audio is 8", that’s why). A popular car audio mod on NC’s is this with a set of Focal IS200. Don’t forget to order speaker harness adapters so you can connect your new speakers to your loom without having to cut it.

Personally I don’t use the rear speakers. Music is made with a left and right channel for stereo effect. But the rear speakers are both on one side so it messes with stereo imaging.

While you’re at it, it would be best to dampen the door a bit. Like this:

You don’t need to stick your door full with them, but I have put some on the inside of the outer door panel as that easily resonates and also a bit on the inside. Besides that I actually used a bit around the speaker openings on the door panel to stop it from rattling. Epic win, it worked! It’s not a lot of work, when you have dismantled your door this should take you not much more than 30 to 60 minutes extra.

This will give you the biggest improvement in sound. There are 2 (or 3 depending on how you look at it) more things you can do.

  • Amplifier
  • DSP
  • Head unit

Obviously an amplifier supplies more juice to your speakers. Nowadays several brands have very small amplifiers that can easily be hidden in an MX5, like the Alpine KTP-445U. A cheaper one is the Pioneer GM-D1004 but these are known to pop at start and shutdown and have a slight background hiss. It’s hit or miss wether the one you buy has these problems.

  • Head unit. More options for connectivity, more adjustment options, probably a bit more power (but that might be negligable as the best head unit don’t give more than 20w per channel in real life), hands free calling etc. I have a double din unit, together with 2din fascia. Gives the car a more modern look inside imho.

  • DSP. I am discussing this as the last point on purpose. DSP’s are very usefull in tuning your sound and can really contribute to better sound quality. The reason why I discuss this as the last point is that you have 3 options to use this.

  1. Medium and higher segment head units usually contain basic so intermediately advanced DSP which is more than enough for an MX5
  2. Some amplifiers have a built in DSP that you can configure with an app. Kicker has a small amp with DSP built in. Pioneer has the same but it isn’t that much more powerfull than a head unit. Though still usefull. These are usually slightly more advanved than a head unit DSP.
  3. Separate DSP. You can buy a separate DSP to modify the signal that your head unit sends out and then connect an amplifier of your choice. These DSP’s are the most advanced for optimizing your sound.

Personally I feel option 3 is overkill for an MX5 as there is a lot of road noise in an MX5 so any extra configuration options might not add much to the sound quality. Besides that, separate parts take up more space, which is not the strongest point of an MX5 :wink: If you want to go further than just replacing speakers I would either get a DSP/amp combination for your stock head unit or get a better head unit with DSP built in (usually if the head unit has time alignment it also has the other stuff you need for the basics and bit more) and an external amp.

I replaced mine with FLI Integrators from Halfords.
They sound much better.
Only issue I found is with the car tweeter still connected, they were shrill, so i ended up disconnecting the OEM door tweeter.

Thanks for the replies, very useful
Owing to my ears getting on, would I notice a DSP ?


Yes. Hearing is not the result of the weakest link (for example your ears), rather it’s a product of all factors.

I have been thinking about the Focal 200 all weekend. They seem very popular stateside, check out the reviews on the crutchfield Web site, where they are $379. Over here they are £139, must be one of the few examples where kit here is cheaper than there.

First I am going the sound deadening of the door panel route to see if that fixes my concerns.

Also interested in your comments above about stereo imaging. I have the Bose (2008 NC1) with the dash speaker. Tempted to simply unplug that and see it it improves things. Was a big improvement doing this in my BMW. Anyone tried this?

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First of all I am not sure what those Focals will do when you replace the Bose speakers with them. Bose uses a very weird resistance value on their speakers, 1 ohm. The Focals are and industry standard 4 ohm, which means the amplifier will probably supply a lot less power to them. Lots of people have on a “Bosectomy”. Google it.

And I would just try to unplug it yes and see if you like it :slight_smile:

I think from reading the stateside comments, the Focals can swap straight in using the Bose amp. You are more likely to cause amp trouble going the other way, i.e. by asking an amp to power a much lower impedance speaker, then it may struggle to push the higher current.

However, I did read that the NC2 setup is different to the NC1 in that the crossover is in the amp, where as the NC1 I assume is in the cabling.
This would mean the NC1 would have a single pair of cables to each door and a frequency splitter module between the speakers; where as the NC2 will have the speakers fed independently by two pairs from the amp.

For this to have any effect, the Focals would need to ship with an appropriate crossover module, otherwise either option would have to use the Bose specification cross over, which could be why some reports say the Focal tweeter is poor, yet others don’t, maybe it is being driven badly.

Does anybody know about the crossover frequency specs?

I plan to take a door skin off my NC1 today to dynamat the speaker surround so will confirm what I find later (weather permitting).

Edit… just noted the focal have the crossover hardwired in the speaker.

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You are absolutely right in that it will not cause any technical trouble. But, let’s say the Bose amp supplies 30 watts to the door speakers @ 1 ohm, then it will be likely that the 4 ohm Focals will get 7,5 watt. And while I am no power-whore, that seems a little low to me. But on the other hand, try and you’ll know :slight_smile: You can always do a Bosectomy if you discover it doesn’t work for you.

Edit: if you look at it from a sound quality perspective I would take out the whole Bose system. Because I would not be surprised if the system applies some form of equalisation tuned to the specific Bose speakers. But that’s just an idea.

Yes, and that’s where the Sensitivity of the speaker comes into play. Decibels per Watt.

For me first step is deadening. Might be enough to make me happy. If not, then bigger things will need to happen.

That is certainly true. Even though I wouldn’t expect the Focals to be 6db more sensitive (which would compensate completely for the higher resistance) but that is just an assumption as there is not much known about the Bose system.

I bought a set of Focal today. Fitted one woofer so far, the Tweeter will need a mounting plate made, no biggy, but not quite plug and play.
With just the one woofer fitted it is easy to compare volume with the standard Bose by playing with the balance. And there is not anything between them. So no fear of loss of volume.
Sound quality is definitely an improvement, which is encouraging as they will take time to bed in and will only get better, and still using the standard high frequency speaker.
No improvement in base extension as yet, which I am hoping for, but may improve as bedding in occurs.

Will add more when I get the rest fitted.

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Sounds good. Maybe you can use an spl meter app on your phone and the balance setting to measure if there’s any difference at all. In absolute terms it might be not calibrated but for all relative difference measure it should be fine.

Have you fitted any damping to the door? My 8" Audisons easily get down to about 40-45hz. 35 is audible but you can easily hear bas is falling off. Still impressive in my book for a not too expensive 8" woofer in a partially damped door.

Also, in my car the difference in bass extension and quality between stock and my Audisons only really became clear after installing both woofers. With 1 woofer I could measure some difference but not really hear it. Weird but that’s what I experienced. When testing 1 stock speaker vs 1 Audison I became worried, which became clear was not necessary at all :stuck_out_tongue:

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I didn’t use any meters, so all thoughts are subjective. I did use some Silent Coat 2mm on the door skin and the inner skin, not much, around a sheet and half each side.

I also connected my phone to the media port on the back of the head unit with a £5 cable off amazon. This works but does not go as load as the radio, so not much use top down at 80mph. Sound quality is on a par with the radio, but no better. My CD player doesn’t work, so most testing/listening was down with the FM radio.

I now have the Focal kit (ISU 200 which is a 20cm/8 inch woofer and a one inch tweeter component kit).

Initial thoughts were that it was a big improvement, but after a day in the car today, I am not so sure.

I also tried unplugging the dash speaker to see if that helped.

My thoughts are that the Focal kit misses a mid range speaker, and unplugging the central dash Bose speaker highlights that. Another thought is that the Bose speakers may just be ‘brighter’ and that compensates for inadequacies with the head unit or amplifier that the Bose speakers cover over, but the Focals expose.

So, were they worth £140 to replace the Bose door speakers? I go back to my initial thoughts that they are a big improvement, and maybe my expectations were too high ànd that is why after spending time in the car today I am a bit disappointed. On balance, yes, worth the money. But at a cost of $380 in the US, I would not be happy.

Next steps are either a new head unit (but still using the Bose Amp) and see what that results with. Or replacing the tweeters with a three inch coaxial mid range and tweeter speaker.

As my head unit has a broken CD, it seems sensible to swap that out. And in hindsight, maybe I should have done this first. The reason I didn’t was I was waiting for the media port connection to my phone, which could have given me everything I needed had it provided the quality I hoped for. It didn’t.

I haven’t been in there to look but as far as I know, my 3.5 has the bog standard set-up, which should be easier to improve on.
My experience is that using an ipod really helps the sound quality from the standard set up.
I am using a Belkin mount on a flexible stalk that plugs into the cigar lighter power supply. The ipod plugs into that and the mount uses a 3.5 mm jack plug to connect at either end of a cable to the head unit.
I just had this lying around from a few years ago, so I don’t know if something similar is still available for more modern phones or Ipods. My ipod uses the old pre-lightning socket.

With audio enthusiasts, Bose is not quite known for their neutral and flat frequency curve. And their speakers also often lean on loud high and low, which means mid range is subdued. Equalisation in the amp might cause this. Not sure but knowing how Bose works I wouldn’t be surprised. Do you have an old home amplifier laying around that you can put in the passenger seat with an extension cable for power and hook that up to the Focals? Knowing the reputation and sound of Focal and the review of these speakers I would be very surprised if mid range on these speakers is indeed so weak. The speaker form/size lends itself very well for reproduction of mid range.

I have also thought of a 3" coaxial in place of the tweeters but I think it’s a bad idea. First, what the Focals will reproduce and the coaxials will have huge overlap while at the same time the distance to your ears are not the same. Second, there is no housing for the mid range so the sound will bounce in between the two door cards which also results in degradation of sound.

I think/hope the source is the weak point, but I was thinking that an 8inch and a 1inch was not optimal. My home speakers (combination of Proac and Bowers & Wilkins) all are smaller than 8", with a seperately amped 10 inch sub)
Do you disagree?

I have a new head unit on order, so am hoping that cures all my concerns.

I do indeed disagree, there are several brands that employ 8" for mid range in home speakers. My own 8" Audisons also have no shortage of mid range. In fact, in the search for an insane deal on tweeters I still run stock tweeters and they cannot keep up with my woofers. Would really be interested in your experience with a home amplifier :slight_smile:

That’s good news, so I hope you are right :sunglasses:

Sorry, home amp test is too much hassle when I have my next step planned with a new head unit. If that disappoints, I might take the door cards off again and make the test feasible. (Got a Cyrus2 in the loft somewhere).

The other fear I have is that there is a cross over upstream from the speakers. I read somewhere that the NC2 has the crossover within the amp, but I think my NC1 has full signal all the way to the speakers and is filtered there. The Focal crossovers are in the connecting cables.

I understand. You can also try to temporarily wire the speakers directly to the new HU, then connect through the Bose amp and share the knowledge with the community and obviously make a decision on what to do based on your findings :slight_smile: