8 inch Midbass

[expo5.0 10+ year member]

wait- explain that again

i've been curious about this- having sort of understood but not fully understood the concept here

 

[B_Campbell 10+ year member]

Did you ever think about going for some midbass 6.5's like maybe the AA Poly mids, XXX mids or the DD 6.5LT's?

 

[squeak9798 5,000+ posts]

wait- explain that again
i've been curious about this- having sort of understood but not fully understood the concept here

Explain the sensitivity issue Tempest spoke of?

It's pretty simple; True sensitivity should be measured with 1w of input at 1m.

With 8ohm speakers, 1w of input works out to be 2.83V because P = V^2/R. So (2.83^2)/8 = 1w....no problems here.

However, many manufacturers use the same 2.83V to measure their 4ohm drivers. Herein lies the problem. Using the above formula, we can see that 2.83^2/4 = 2w. So the sensitivity for that 4ohm driver is going to be overstated by 3db

(10*log(2/1) = 3db).

So if you were comparing two drivers, one 4ohm and one that is 8ohm, with the same stated sensitivity of (for example) 92db and they were both rated using 2.83V.....the 4ohm driver would only have an actual sensitivity of 89db since it's sensitivity was overstated by 3db due to it receiving 2w of input rather than 1w. Thus, the 8ohm driver has a higher true sensitivity.

Many times you'll see an driver with it's sensivity ratings stated as being "2.83V/1m". This is perfectly fine w/ 8ohm drivers because it is exactly the same as "1w/1m". However, if it's a 4ohm driver that you see with the sensitivity being stated at "2.83V/1m" rather than "1w/1m".....you'll now that the sensitivity is actually 3db lower than stated.

Here is a prime example;

Dayton Reference 8" 4ohm driver - Sensitivity stated as being 92db @ 2.83V/1m (which is likely a rounded figure aswell)

DIYMA review of the driver - Measured sensitivity of 88db @ 1w/1m (rounded)

Another way to figure out what the actual reference sensitivity for a driver is if it's not stated 2.83V or 1w is by using the formula I posted in another thread;

http://www.caraudio.com/forum/showpost.php?p=2581740&postcount=6

 

[squeak9798 5,000+ posts]

http://www.caraudio.com/forum/showthread.php?t=183830

Finding an 8" mid to go with horns is a little different than finding an 8" midbass to go in a conventional setup. So I'm not sure that really applies well to him.

Anyways...I agree that the first thing you should do is fiddle more with the tuning, enclosure, phasing, etc before switching drivers.

 

[Oak244 10+ year member]

Here are my 8" drivers. They play from 50Hz-1.25Khz. They are Peerless Exclusives 8ohm , matched with Peerless HDS tweets. I just finished the tweeter pods today, now they just need painted, and I am still waiting for the vinyl to arrive to finish the 8" pods.

 

[SpasticGramps 10+ year member]

Here are my 8" drivers. They play from 50Hz-1.25Khz. They are Peerless Exclusives 8ohm , matched with Peerless HDS tweets. I just finished the tweeter pods today, now they just need painted, and I am still waiting for the vinyl to arrive to finish the 8" pods.

Definitely and interesting discussion about the 8ohm drivers. I did not know that, but physically it makes perfect sense.

I've been playing around with the EQ today some and still feel the CDT EF-8 drivers aren't going to produce the kind of sound quality that I want them too. I really believe these drivers around not made to work well IB and perform high quality midbass frequencies. The driver's suspension is significantly looser than any midbass speaker I've seen. It looks like an 8 that would perform awesome given the right sealed enclosure and playing low frequencies. It's spec sheet rates it's range from 10 - 400hz. Clearly once this speaker reaches true midbass frequencies it's at top end of its capabilites.

Oak, how would you rate those Peerless Exclusives?

I don't want to put in 6.5 drivers because my doors have been modified to hold the 8's and I'm trying to drop in these drivers with no or as little modification as possible.

 

[Megalomaniac 5,000+ posts]

Here are my 8" drivers. They play from 50Hz-1.25Khz. They are Peerless Exclusives 8ohm , matched with Peerless HDS tweets. I just finished the tweeter pods today, now they just need painted, and I am still waiting for the vinyl to arrive to finish the 8" pods.

that reminds me of josephs(~magic_man~) sentra, he has daytons in his door

 

[Oak244 10+ year member]

The Peerless Exclusives are very nice drivers. Very detailed for sure. I have never heard Norah Jones sound so beautiful in a car before this setup! And for the first time, I can truely hear the bass player in Dave Matthews Band seperated from the bass drum of the drummer. In all my other setups, it was a mix without a true seperation. I have a 15" SI Mag run with 1050 watts of Arc Audio XXK power, so I was not worried too much about low bass quality. I was told the Exclusives were not the strongest at low end punch, but were the most detailed speaker I could get. Honestly with the SI sub and these Exclusives, I have more then enough bone rattling Bass and Hit in your chest midbass. Tomorrow I am going to start tweaking the system... ie gain sets, time alignment and start EQing. I can't wait to hear the results. I am already very happy with the setup the way it is. I can truely say now, that speaker placement means everything! The Exclusive 8's have very little roll off at even 60 degree's off axis, so those did not have to be on axis, but still I was able to turn them so they are only 30 degrees or less. The HDS tweeters on the other hand had bad roll off even at 30 degrees, so it was much more important to have those as close to on axis as possible, and by doing so, my sound stage is awesome!!

 

[SpasticGramps 10+ year member]

awesome review about the 8's. My subass setup is def. not a truly SQ setup as you can see by my signature, but I'm trying to get my frontstage as tonality accuratte with as much loudness as possible, to "attempt" to keep up with the sub stage as much possible. I find since the DD drivers are breaking in they are becoming more tonality accurate at lower volumes.

Where would I find an authorized dealer to talk to about the peerless drivers. And what driver would suit my needs

http://www.peerlessaudio.com/products/drivers/main3.asp?filename=4

I see a couple 8ohm drivers. The PG Xeon gives 200w / channel through 1-4ohm config.

 

[Oak244 10+ year member]

Well many use this place http://www.madisound.com/

I have used this place myself with great success http://www.meniscusaudio.com/

And for 8 Ohm midbass drivers I would search this site. http://www.diymobileaudio.com/forum/

And for those debating about 8Ohm drivers here is a good read..

http://www.diymobileaudio.com/forum/showthread.php?t=31

If you are only looking for a midbass that does to 400hz or so, I would say the Exclusives are not what you need. The Exclusives are really for a 2 way system. Search the DIY site for reviews and such, and I am sure you will find the right driver.

 

[6spdcoupe 5,000+ posts]

Surprised noone chimed in with Dyn MW182s...

 

[SpasticGramps 10+ year member]

I'm really only concerned about a 3 way system, I have CDT HD 4 1/2 components and two 2 1/1in AVI center channels. They do a great job of producing the higher end of the spectrum. It's just the midbass that I'm lacking.

It really looks like the critical mass drivers are becoming the most viable option. I hate to be a sucker for mass marketing, but the review by C & A about their 12in flagship sub is undeniable. It sounds like that this company is an emerging force as far as SQ and power handling are involved.

I've seen the Dynaudio speakers on partsexpress.com, but am relucant because of their low cost. I would love to find a speaker of high caliber at a decent cost, but am wary emerging audio companies.

So I'm ramballing now and am done. Thanks.

 

[6spdcoupe 5,000+ posts]

What drivers is it that you saw on PE from Dyn? They dont carry them. Madisound also only has parts, not the full drivers. If youve stummbled upon pricing somewhere and think they are 'low cost' then your wealthier than I and should Definately give them a listen.

 

[JonJT 10+ year member]

well another is the critical mass MB82. its a 2 ohm neo motor that is front mounted for a shallow mounting depth. they work infinite baffle and do from like 40hz~2000hz. they are intended for strict midbass duty. they are on the top end scale of the prices you are looking for. so i dont know about that part.

http://criticalmassaudio.com/catalog/index.php?act=viewProd&productId=5

you have any detailed T/S specs for that driver? The website doesn't help.

 

[expo5.0 10+ year member]

and the cost... if i could get over how much they'd ruin the flow of my doorpanels i'll maybe run them...