Rear speakers and ventilation
Discussion
So here's the problem.
My 1999 Chim came with a Pioneer radio cassette and multichanger, and 4 Pioneer speakers. I am guessing but I think all were fitted from new. Soundwise, the rear speakers were very thin and insubstantial sounding compared to the door speakers, and on closer investigation, the reason is obvious: the spacer rings fitting them to the rear bulkhead had a row of holes! Now as any fule kno you just do not get any bass without a decent enclosure, so I thinks aha ... took them off, sealed the holes and re-installed. Great improvement, much more solid sound.
Then .. read my newly acquired bible and learnt that the holes were there for ventilation as there was originally a grill there, and the car will be much more difficulty to demist without them. Sure enough, the car is now virtually airtight and last night it was more difficult to demist. Plus there is a strange feel of pressure with the windows up at speed.
So, can anyone offer me advice as to how to restore some ventilaation without losing my newly improved sound? New grill in the centre? If well away from the speakers I reckon I should retain most of the sound, but how do I make a hole and where can I get a grill to cover it. Probably best not to drill into the petrol tank I think.
Great thread by the way guys, and as a TVR owner of one months standing, a great source of help and amusement.
My 1999 Chim came with a Pioneer radio cassette and multichanger, and 4 Pioneer speakers. I am guessing but I think all were fitted from new. Soundwise, the rear speakers were very thin and insubstantial sounding compared to the door speakers, and on closer investigation, the reason is obvious: the spacer rings fitting them to the rear bulkhead had a row of holes! Now as any fule kno you just do not get any bass without a decent enclosure, so I thinks aha ... took them off, sealed the holes and re-installed. Great improvement, much more solid sound.
Then .. read my newly acquired bible and learnt that the holes were there for ventilation as there was originally a grill there, and the car will be much more difficulty to demist without them. Sure enough, the car is now virtually airtight and last night it was more difficult to demist. Plus there is a strange feel of pressure with the windows up at speed.
So, can anyone offer me advice as to how to restore some ventilaation without losing my newly improved sound? New grill in the centre? If well away from the speakers I reckon I should retain most of the sound, but how do I make a hole and where can I get a grill to cover it. Probably best not to drill into the petrol tank I think.
Great thread by the way guys, and as a TVR owner of one months standing, a great source of help and amusement.
Yes I've heard this but find it hard to believe. Think about it for a moment, as has been said, i) the carpet behind the doors is only pushed in place to allow access to the door solenoids, ii) the hood only Velcro’s in place at the sides iii) the heater (despite it's other faults) allows fresh air into the cabin, I really can't see how a soft top can be air-tight. Sounds like another one of those TVR urban legends to me, anyway to solve the problem just crack the window an inch or so. Rich...
DustyC said:
Speakers in the back of the car?
Madness.
Do you go to a concert and turn around to face the back wall to listen to the band?
no, but then again do you stand on the stage and turn the speakers in either side so they are facing your knees?
LOL
Seriously though the rear speakers help shift the centre point of the sound closer to your ears giving better stereo sound.
Paul
[quote=DustyC]lossen the speakers, fit some spacers with airgaps, tighten speakers again.
Dusty, that's where I started. Anyone with 4 speakers and spacers with holes can test it for themselves, just by turning the fade front to rear and listening to the difference. In my case, 4 Pioneer speakers, same size, and no bass from behind. I now have the sound quality but no ventilation. The car IS more airtight, and that is exactly what the bible said - read the interior chapter.
I don't want to throw away the gain I have just made, so I guess a central vent is the answer, but will have to look for a grill to cover the hole I cut.
Thanks for the input guys. By the way, anyone fitted speaker upgrades or an amp. I know, I know, the 8 track sound is best, but it is my everyday car and does some motorways,
Dusty, that's where I started. Anyone with 4 speakers and spacers with holes can test it for themselves, just by turning the fade front to rear and listening to the difference. In my case, 4 Pioneer speakers, same size, and no bass from behind. I now have the sound quality but no ventilation. The car IS more airtight, and that is exactly what the bible said - read the interior chapter.
I don't want to throw away the gain I have just made, so I guess a central vent is the answer, but will have to look for a grill to cover the hole I cut.
Thanks for the input guys. By the way, anyone fitted speaker upgrades or an amp. I know, I know, the 8 track sound is best, but it is my everyday car and does some motorways,
rbryant said:Yep, read it, indeed heard the theory years ago before Steve wrote a bible for Griffs and Chimaeras, all I am saying is that I don't belive it to be true. Is the boot space ventialted? No thought not, so venting the cabin into the boot will have no effect anyway!
The car IS more airtight, and that is exactly what the bible said - read the interior chapter.
Rich...The best way to fit rear speakers is to take out the vents but keep one. Replace the vents with some 6x9 subs I think mine were Gennis (But not sure). You need to make sure no air what so ever can get passed the speaker's (they will sound rubbish if you don't) and then cover the back panel with dinomat and lots of it. The rear panel is very thin and you will lose a lot of bass if you don't. Once thats done get one of your vents and cut a hole dead in the center of the rear panel between the to speaker and fit. Job done .Very punchy bass 
P.S If you fit subs you will also need an amp with built in crossovers.
Hope this helps
Dave
P.S If you fit subs you will also need an amp with built in crossovers.
Hope this helps
Dave
I've put rear speakers in - think Pioneer TS1375(13cm 130w) which now means I can hear the music on long journeys with the lid off - weren't too bothered about spending a fortune for better speakers. Looked at 6x9's but require too much work and are too deep without the spacers. The only issue was with the depth of the speaker as the fuel filler pipe sits just behind the vent on the n/s (Griff).
They were easy to fit - just had to file (mini files) a groove out to get the 4 fixing pieces in otherwise no other work. Took about 3 hours with the help of Mrs FFG. Most difficult bit was lining up the holes from the front as didn't want to damage the carpet - solved by putting a sharp object (needle) in from the rear for guidance and then screw tight. They are flush so still gives full use of the rear shelf without damaging anything.
No problems with ventilation as the vents are open, the seal at the top of the window isn't perfect and the window is open most of the time.
If there was a problem I would cut another hole in the centre and use one of the removed grills.
FFG
They were easy to fit - just had to file (mini files) a groove out to get the 4 fixing pieces in otherwise no other work. Took about 3 hours with the help of Mrs FFG. Most difficult bit was lining up the holes from the front as didn't want to damage the carpet - solved by putting a sharp object (needle) in from the rear for guidance and then screw tight. They are flush so still gives full use of the rear shelf without damaging anything.
No problems with ventilation as the vents are open, the seal at the top of the window isn't perfect and the window is open most of the time.
If there was a problem I would cut another hole in the centre and use one of the removed grills.
FFG
Dave, thanks for tip on the dynomatt (sp?) i'll give it a try. Also, I notice that the hole in the rear bulkhead is only just big enough for the magnet to pass through, (Blackpool TVR fitted) i would have thought that making it as big as the outside cage will allow the cone to flex more easily?
FFG - agree about ventilation (see below) also just remembered there is a ventilation groove that runs under the rear hood and out in front of the boot lid where it fits to the rear bulkhead. I know this allows air-flow as I have a grimy/dusty area on the carpet there. Rich...
>> Edited by RichB on Tuesday 20th July 15:19
FFG - agree about ventilation (see below) also just remembered there is a ventilation groove that runs under the rear hood and out in front of the boot lid where it fits to the rear bulkhead. I know this allows air-flow as I have a grimy/dusty area on the carpet there. Rich...
>> Edited by RichB on Tuesday 20th July 15:19
I'm now tempted to upgrade the speakers and maybe an amp, so Corin, please do tell how it all works out.
Dynamat also, but can you explain more - I can only see how to feed if through the hole the speaker goes in and stick onto the fibreglass behind, or are you working from the boot end?
As to the ventilation, I can only tell it as I find it, and other holes notwithstanding, it did what I said once I closed off the spacer holes.
Dynamat also, but can you explain more - I can only see how to feed if through the hole the speaker goes in and stick onto the fibreglass behind, or are you working from the boot end?
As to the ventilation, I can only tell it as I find it, and other holes notwithstanding, it did what I said once I closed off the spacer holes.
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