Suggest a system - start from new

This section is for technical Q & A only - any other threads will be deleted/moved. Please try the search function before starting a new thread.
The forum Administrator has chosen to advise you that this topic is 6 years and 8 months old and that you may wish to begin a new topic or use the search feature to find a similar but newer topic.
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »

Image

Only photo I can find atm!


Rev5 Sonic Shadow
Image
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »



Doesn't really show how it sits though :laughing
Rev5 Sonic Shadow
Image
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

Hmmm....Looking at that, it looks like both above and below could be a possibility?

I might get Erin to measure the riser behind the seat, see if below is an option. Keeps it out of sight (although my tints might help there :laughing )
1993 Revision 3 Turbo - Restoration Underway
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

Ah nuts!!

The height of the riser is 195mm and the distance from the top of the box {that I can see) to the underside of the window trim is 135mm :facepalm:

OK, Would I still be able to get the glass behind if the amp is mounted on the driver's side?
1993 Revision 3 Turbo - Restoration Underway
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

Found this amp....

http://www.caraudiodirect.co.uk/amplifi ... ensor-400w

I'm planning on buying these speakers

http://www.hertzaudiovideo.com/car-audi ... esk165l_5/

And This Sub

http://www.hertzaudiovideo.com/car-audi ... y-es250_5/

What's appealing about that amp is that it would happily fit below the sub box on the riser :th:
1993 Revision 3 Turbo - Restoration Underway
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »

That amp is way under spec unfortunately Jay. You'll be punishing that amp to try and drive that sub and those speakers (look at the power handling specs, specifically the RMS power). If it had twice the power it'll be fine, but then it would be twice the size!
Rev5 Sonic Shadow
Image
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

OK, so how do I select an amp?

All these numbers are spinning me out :laughing
1993 Revision 3 Turbo - Restoration Underway
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

I've also found this one or is it overkill?

http://www.caraudiodirect.co.uk/amplifi ... -d-car-amp
1993 Revision 3 Turbo - Restoration Underway
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »

The power ratings should match roughly - generally speaking, a speaker rated at 90WRMS needs a bit of power to really get it to come alive. It'll work with a lower power amp but you end up running the amp at 100% just to get something out of your speakers. You then run the risk of clipping the amp as it's running flat out which can damage the amp and the speaker. You're much better off running a more powerful amp at 70% potential than a lower power amp at 100% for example.

Most speakers you'll find will be 4ohm which is fine - the impedances need to match as well. Watch out for dual voice coil subs - you might see some subs with two 4 ohm voice coils. These can be wired in series or parallel to give 8ohm or 2ohm. 2ohm is nice if the amp can do it as you get more power. Your typical 4 channel amp can't do 2ohm in bridged mode though. Best to just stick with 4ohm for simplicity.

That amp looks good VFM on the spec. Reason for this is it's a class D amplifier. Class D's are very efficient and aren't as expensive to build as a good Class A / Class AB. Typically Class D's aren't as good quality-wise in higher frequencies which is why you often see 1 channel Class D dedicated amps for subs, high frequency performance is irrelevant there.

Looking at the power ratings, they've measured at 1% total harmonic distortion. That's quite high. The previously mentioned Dream 4 power outputs are at 0.04% THD...

Saying that though the reviews are good, so perhaps it's not audible unless you really give it a hot supper and run it to 11?
Rev5 Sonic Shadow
Image
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

OK, so if I have this right.....

2 Amps - GM-A6604 and GM-D8604

One is a D Class amp, one is an AB Class(?) The A class will be better?

Both amps have a THD of 1% - Equal there

GM-A6604

Front Channel - Continuous Music Power 60W per side
Rear Channel - Continuos Music Power 180W Bridged

GM-D8604

Front Channel - Continuous Music Power 100W per side
Rear Channel - Continuous Music Power 300W Bridged

ESK 165.5 Components - Power Handling - Continuous W 100
ES 250.5 Sub - Power Handling - Continuous W 250

So the GM-D8604 would be better suited to the speakers selected? Or would the quality of the AB Class outweight the deficit on continuous music power?
1993 Revision 3 Turbo - Restoration Underway
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »

It's one of those things where it's impossible to tell on paper - You can get really good class D's and really poor Class A/B's. Looks like power rating at less than or equal to 1%THD is common for car audio amps looking around... The Rainbow one measuring at a lower percentage (Class D as well as it happens!) is the outlier.

Looking at the reviews for the GM-D8604 I can't see any that have a bad word to say about quality for the money so I think that would be a decent choice. Certainly got the power to make those speakers dance!
Rev5 Sonic Shadow
Image
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

OK, cool....as they are both exactly the same price, I'll take a punt on that one :th:

Wow! Looking at the literature, the inline fuse for that one needs to be 80A :blink:

That's a beast!!!
1993 Revision 3 Turbo - Restoration Underway
User avatar

SonicSW20
Posts: 2858
Joined: 29/11/10 19:50
Years of MR2 Ownership: 10
MR2's Owned: 3
Location: UK
Been thanked: 6 times

Re: Suggest a system - start from new

Post by SonicSW20 »

Aye, that's very much last line of defence... I've not popped an in line fuse (or set my car on fire) in 6 years between two cars :th: if the inline goes then something has gone very wrong!

Well worth getting some Dynamat, Second Skin, Silent Coat or similar for the doors too. Silent Coat do a door kit that comes with a few different types which is handy!
Rev5 Sonic Shadow
Image
User avatar

Topic author
MR2Jay
Posts: 4966
Joined: 20/03/08 11:45
Years of MR2 Ownership: 10
MR2's Owned: 7
Real Name: Jay
Gender: Male
Location: Northampton
Been thanked: 8 times

Re: Suggest a system - start from new

Post by MR2Jay »

I was looking at that, as well as trying to work out how to do MDF adaptors for the speakers....

First stage I think is to run the wiring and get the headunit in. Once that's in place, I can get rest as and when I can afford itand build up the system :th:
1993 Revision 3 Turbo - Restoration Underway

Quick Reply

   
The forum Administrator has chosen to advise you that this topic is 6 years and 8 months old and that you may wish to begin a new topic or use the search feature to find a similar but newer topic.

Return to “ICE”