using car audio components in home

[pjoseph]

I have a pair of 6.5in Alpine car audio component speakers that i no longer use for my car.

I purchased them about three years ago and at the time they cost me around $400.

They are in fiberglass enclosures right now from when they were in my car and I have hooked them up in my room just to test them out and they sound fine.
I want to build new enclosures for them so I can use them in my room as my front speakers for now until i upgrade, then i can always use them as the surround speakers.
I am looking for advice on what I should make the internal volume of the enclosures for these speakers.
Thanks

 

[annunaki]

You will need to get the theile/small parameters for the woofers in order to get the correct enclosures for the speakers. You will also need to be sure the receiver/amplifier is capable of handling a 4 ohm load. You should be able to get the tech specs from Alpine's website.

 

[pjoseph]

Yea i just found the manual so I do have the specs also I plan on upgrading my receiver soon aswell, although my old pioneer receiver is rated at 8 ohms it did not have any problems powering them.

Thiele/small (Mid range)
ReDc 3.1
Fs 31Hz
Qts .32
Qms 4.1
Qes .35
Vas 53 liters
Sd 129 cm^2
Le .4mH
Cms 2.3mm/N
Mms 11.5g
Bi 4.6T-m
Now I am not sure what I have to do with these numbers to determine the internal box volume, so if someone could help me out I would appreciate it.

Thanks

 

[annunaki]

I will let you know when I get a bit of time here shortly.

 

[pjoseph]

I am trying to use winISD but have a few questions
I am unable to find the following in the manual:
SPL--not the same as sensitivity is it because it was the only one listed in dB
dia----is that the diameter of the woofer?
pe ?

anyway i tried it leaving those blank and it said volume should be 13.7l, also that is just for the midrange do I have to build the box for the tweeter seperate or can i just mount it in the same enclosue as the midrange.


Thanks again.

 

[jcPanny]

Speaker specs

Your previous post indicated that the diameter of the speakers was 6 1/2".
The sensitivity is a measure of how loud the speaker plays with a given power input. It is usually listed is ??? SPL @ 1 Watt @ 1 meter.

 

[annunaki]

The tweeter can be mounted into the same enclosure.

Pe is thermal power handling. usually closest to the rms power handling of the speaker.

YOu will want to use much bracingand absorbtion materials in your cabinet when you build it to get the best performance out of the speakers. I did not get a chance to model the speakers last night. I should tonight though. Sorry.

 

[johsti]

Curious, what Alpine speakers are they? I have some Alpine SPX-177a components laying around and was considering building an enclosure for them. They sounded great in my car.

 

[pjoseph]

They are the same Spx 177a

Annunaki
Thanks for your help
If you could do that i would appreciate it if there is any info i left out let me know like i said i tried it but could not find two of the specs listed on winisd
but ran it anyway and posted the results in the other post see if you get something similar.
With the speaker filling are you refering to pollyfill?

Thanks again

 

[annunaki]

They are the same Spx 177a

Annunaki
Thanks for your help
If you could do that i would appreciate it if there is any info i left out let me know like i said i tried it but could not find two of the specs listed on winisd
but ran it anyway and posted the results in the other post see if you get something similar.
With the speaker filling are you refering to pollyfill?

Thanks again

Actually I am referring to a mineral board or a compressed fiberglass type board that can be lines on the walls of the enclosure. A very dense mineral wool would work well also. Basically, besides the bracing you will want to absorb any stray midrange energy that may lead to resonance. Heavy bracing helps to shift the resonance point above the band of the midrange and the lining helps to absorb any stray energy. Coupling this with driver isolation from the cabinet can result in a near resonance free enclosure. This will greatly help to increase the clarity and detail of the system. I believe those drivers and tweeter are both vifa designs and should do quite well.

I have the big type-x 3-way set from 2 or 3 years ago that I had in my vehicle. I may do a set of three way towers with it at some point. They were the set that retailed for $800 or so I believe.

 

[annunaki]

My program only plots up to 500hz, but it is suggesting a .9 cu.ft. enclosure tuned to 40hz with a 2" port 4-3/16" long. The other option would be a passive radiator design. This allows for a cabinet of .5 cu.ft. using the this passive radiator

The big issue I am seeing is that the speaker exceeds excursion limits at around 100hz with 75 watts rms. I estimated the excursion at 5mm. It will essentially starts bottoming around 80hz-90hz. This seems to happen no matter ported, sealed, or passive radiator design. If this was not a problem, the ported enclosure would have a -3db point of 41hz and the passive radiator system would have a -3db point of 59hz.

Otherwise it seems like it should work pretty well.

 

[pjoseph]

As far as wood I was going to use a MDF board is that ok that is usually what is recommended I know at least in the car audio world?

As far as the port can i place it anywhere, and the 2 inchs is that that the outer diameter or the innner diameter?

Also how much room should there be between the end of the port and the rear wall of the enclosure or does it not matter. Since the port is going to go in 4 3/16 deep what is the minimum dept I should make the box?

Thanks again.

 

[pjoseph]

""Actually I am referring to a mineral board or a compressed fiberglass type board that can be lines on the walls of the enclosure. A very dense mineral wool would work well also.""

Could you provide me with a link for the above material I really am not sure what you are talking about?
Is is something i just line the inside of the walls of the box with?

Thanks again

 

[annunaki]

Go to www.mcmaster.com and put in the sku number 9328K41 in the search section. This should work quite well. Yes, you would line the walls with it. You will want to build the enclosure slightly bigger due to the displacement of the mineral board/wool.

MDF is fine. I will be remodeling these speakers again later as I figured out how to increase the bandwidth on my modeling program. Normally it was set to full bandwidth but got switched somehow. Thanks avaserfi!!!

The port will need, at minimum, it's diameter clearance from any internal wall. So if you have a 2" port it needs a 2" clearance. 2" refers to the inner diameter. Aero port

 

[annunaki]

Upon opening the bandwidth on my modeling program, I have found that the speakers start rolling off on the high end at 500hz. They have a -3db point below reference at 1,229hz on the high end. It does not matter what enclosure type I use. This will be an issue in terms of blending with the tweeter. I hope that the crossover has a correction circuit for this problem. It would help if the tweeter has a low Fs. However, I am thinking that is doubtful.

What looked very promising to start is not looking so well sorry to say

You can put it all together and listen to them, however you may want to design a new crossover. They might sound good enough???

 

[pjoseph]

I will try them out anyway I have no use for them and I enjoy a good project.
I am just getting into home audio like i said so the speakers i am currently using are old sony's from a old minisystem I had. I am also using a pioneer receiver that is at least 7yrs old. I am looking to get all new stuff but I want to do some more reading before i make any big purchases so i figured this will keep me busy for now.

Anyway

I really appreciate your help and i will let you know how they turn out. It may be a while until i get started since i am doing some traveling for three weeks first to atlanta then to california for work but i will start when i get back.

thanks again.