Speaker Upgrades - That still have bass

[Xbdition]

Originally Posted by ka-t_240

Hey everyone,


Does anyone have an experience in upgrading/changing the factory speakers on these cars? I would like to updgrade, but still want something that produces decent bass, and adding a sub is not an option.

I'd seal and deaden the doors first and see how you like it. Even if you end up buying new speakers, sealing and deadening the doors should be your first step.

I don't think you said anywhere that adding a few pounds is your major concern, but that you didn't want to eat up anymore trunk space.

That OEM amp in the trunk only powers the door speakers, so you could easily put a small 2 channel amp in it's place that will push enough power to a really nice set of midwoofers. An amp with both low and high pass filters would be good. Run power and ground to the amp, have a set of door speaker adapters made according to the speakers you choose, and you can have as much midbass as you'd like, depending on how much you want to spend. Simple enough to do IMO.

[ka-t_240]

Originally Posted by Xbdition

I'd seal and deaden the doors first and see how you like it. Even if you end up buying new speakers, sealing and deadening the doors should be your first step.

I don't think you said anywhere that adding a few pounds is your major concern, but that you didn't want to eat up anymore trunk space.

That OEM amp in the trunk only powers the door speakers, so you could easily put a small 2 channel amp in it's place that will push enough power to a really nice set of midwoofers. An amp with both low and high pass filters would be good. Run power and ground to the amp, have a set of door speaker adapters made according to the speakers you choose, and you can have as much midbass as you'd like, depending on how much you want to spend. Simple enough to do IMO.

What is your suggestion for sealing the doors? I did pull my pass. door panel off and add a bunch of strips of a Dynamat style product to the door panel and on the door itself as the rattles were driving me bonkers. I would have done more, but getting the plastic to reseal was a big concern to me.

[Xbdition]

http://www.raamaudio.com/pages/How%252dTo.html

That's a good guide. I've had good experience with their products btw. I've stopped trying to use chicken wire or flashing to reinforce sealing of large holes. Haven't really noticed a difference vs reinforcing.

[TOOSTUBBORN2FAIL]

Keep in mind Dynamat performs significantly better than Raamat, and is lighter.

[Xbdition]

I used Dynamat Xtreme for my 86 this time around and don't have any complaints, but what would make you say Dynamat performs significantly better than Raamat?

[TOOSTUBBORN2FAIL]

Sorry for the lag, been super busy.

Are you a diyma member? If not, checking the last post of the deadening materials sticky on this forum's audio directory.

http://www.ft86club.com/forums/showt...t=13845&page=4

I didn't link the raamat bxt2 test, but it measures within a hair of stinger roadkill expert, which is shown right next to dynamat.

[Xbdition]

Interesting results. Would you be able to lay damped frequency response and decay graphs over one another? Say...Xtreme vs Raamat?

I'm afraid of what the decay graphs would look like laid over one another. Looking at those gives me a headache.

Why are the bare metal FR graphs so different between stinger and dynamat?

[TOOSTUBBORN2FAIL]

There are slight differences, mostly due to having to unclamp the panel between every product test to remove the previous product. This is why each product gets its own metal test. With more funds, I would have had a machined metal clamp made for the panel, instead of wood, but my wife was laid a few weeks before starting testing, but after I had received samples.

That said, the consistency has shown to be good to +/- 1db. That said, dynamat performed 3db better than raamat, and the decay was much quicker.

[Xbdition]

What part of the graph are you talking about when you say 3db "better?" Also, the bare metal graphs show 3-6db variances at certain points between graphs, rather than +/- 1db.

I'm not sure what to make of your results. If more bass is a positive consequence of using deadeners, the area under the curve of the stinger looks better to me than dynamat below 80hz, particularly taking the delta with bare metal graphs into account, while dynamat looks better 80-100hz.

Curiously, aside from smoothing that nasty peak around 85hz, both Stinger and Dynamat appear to be poor for midbass from 80hz and up.

Quicker decay is good of course, but the slope doesn't look significantly steeper to me with dynamat than stinger, and I wonder if that is enough to qualify dynamat as "better" than stinger or raamat if, judging by the dynamat graphs, it does very little compared to the baremetal graph below around 80hz while in the stinger graph you gain at one point up to 7db vs the baremetal graph.

Are you saying that ~3db peak around 75hz of the damped Stinger vs the smoother Dynamat curve is what makes Dynamat better?

[CatDaddysBBQ]

A small low profile 8" sub weighs less than 8lbs (with a 150w amp). Costs 250-300 with wiring kit. Then you can remove the bass signal from the other speakers and then they don't sound that bad.

[TOOSTUBBORN2FAIL]

There are a few things I look for. One is the difference between the peak amplitude of the main resonant mode of the bare metal compared directly to the damped metal. Dynamat reduces peak amplitude by around 11db, while stinger reduces it by about 8db.

I also look at the steepness of the decay. This is easier for me as I can use rew and change gate times to see when the resonant mode decays into the noise floor. But, dynamat does decay faster, which is good.

It's important to note that all damping products are narrow band treatments, ie they only work well at the natural frequency of the panel they are applied to.

I will be retesting stinger, as I have enough material to test multiple runs of most products I have before finalizing the report. When I talk +/- 1db, I'm talking strictly about the reduction in peak amplitude with the same product. For instance, I tested 3 samples of SDS CLD Tiles a few months apart, and the difference in that reduction was within a db of each other.

Because there is an inherent error factor, I generally refuse to say a product is better than another unless it performs better than another by 3db+, and/or decays faster. In the case of dynamat vs raamat, dynamat decays about 20-30ms faster. Not a lot, but it's enough to make a difference when combined with the reduction in peak resonance amplitude.

I'm actually leaving town this weekend for vacation, but when I get back, I'll fire up rew and get some more detailed views that will show the difference in decay between products.

[TOOSTUBBORN2FAIL]

Re-reading this as I was half asleep, I left a couple things out.

Another problem with raamat is it's lower heat resistance than dynamat. I'm not saying that raamat is going to fall off like peel n seal, BUT, all dampers are temperature dependent. The wider range of temperatures a product is stable at, the better it will work at those ends of the spectrum. All tests here were done at 77 degrees F. However, tests by other sources have shown that pretty much all butyl products peak at or slightly below that temp, and lose effectiveness fast. The products that are stable at higher temps fall off slower. So, dynamat will be more effective than raamat when it's 100 degrees outside.

The other thing is missed I'd the reason these products are said to help bass. And that is the reduction of resonance. Resonance simplified down is distortion, of a high order. For instance, let's say your sub is playing 30hz, and your panel is resonating at 90hz, that's 3rd order distortion, which is particularly offensive (as are all odd order distortions). Reducing that distortion even by a little bit goes a long way to making things sound cleaner. There is a school of thought (that I agree with) that low frequency distortion is more audible, due to the equal loudness curve. For instance, a sub playing 25hz will barely be audible, but it will be felt. But it's distortion at 50hz will be heard, as will any distortion at higher orders. That's because our ears are not as sensitive at 25hz as they are at 50hz. They next time someone says they are hearing 20hz from their subs, remember they're not hearing the fundamental note, but the distortion from the subwoofer. This is why I have three 12"s and a ported 8" in my living room. I don't listen loud enough to max them, but having that much cone area reduces distortion.