Another Peerless 830883 execution

[swin1]

Hi there, it's been a while since I've spent time on the forums but thought I'd post another build I've completed. It follows from a similar project I built a few years ago: Another Peerless 830875 execution

This project is another 2-way design using the Peerless Exclusive 830883 7" driver combined with a Vifa/Peerless D27TG45 tweeter in a tower enclosure.

http://photos.swinbank.fastmail.net/moser/PeerlessD27TG45_1.jpg

http://photos.swinbank.fastmail.net/moser/PeerlessD27TG45_2.jpg

http://photos.swinbank.fastmail.net/moser/PeerlessD27TG45_3.jpg

The enclosure is about 20L internal volume (accounting for driver/bracing/port etc displacement) with a 240mm wide baffle rounded on the sides, tuned to about 40-45Hz. It's constructed of 19mm thick MDF all-round with recycled Victorian Ash side panels (an Australian timber) that were originally floorboards in someone's home (probably dating back to the early 20th Century!) The enclosures have been professionally painted with a polyester white and epoxy resin applied to the timber resulting in a smooth semi-gloss finish.

They have been built as a long standing wedding gift for a relative who helped pay for the painting. I've been running them the last couple of days and am down right impressed with their sound. Soundstage, imaging, bass performance, it's all there. I haven't been involved in diy audio for a while and never invested in measuring equipment, relying on using drivers that I can employ Madisound to design crossovers for. I guess in this way, a good baseline is set for further tweaking if necessary for other DIYers out there. I'm happy to post the LEAP design and modelled response here:

http://photos.swinbank.fastmail.net/moser/LEAP%20crossover.jpg

http://photos.swinbank.fastmail.net/moser/LEAP%20response.jpg

I'm so happy with these 2-way speakers with a 7" midbass. I live in an apartment in the inner city of Melbourne with a 20m2 living room and think this size of speaker is the sweet spot, and they easily handle those Hollywood blockbusters we all love for the sound (but maybe not so much for the plot!)

Cheers
Andrew

 

[PeteMcK]

nice work

 

[mondogenerator]

That's some bass shelf there....over cooked the BSC?

 

[swin1]

Between 200 and 900Hz? Yeah I thought the same but it stays level from 1Khz. The crossover point is 1.8Khz.

 

[5th element]

That's some bass shelf there....over cooked the BSC?

That looks like there are around 4dBs of BSC. Each major div is 7dB, minor ones being 1.4dB. The shelf covers just under three minor ones = 4.2dB.

 

[mondogenerator]

Agreed, but is this electrical or acoustic FR? And does the sim account for radiating space (2pi/4pi)? I would've thought that it does not account for that, or else, with BSC the acoustic output would show no rise at LF.

 

[fjadouce100]

Hi Swin1, I am interested in realizing a similar project with peerless woofers and as you have enough experience with both tweeters namely 830883 and 830875 , honestly could tell me which one is more appealing and gives you more satisfaction as sound is concerned .
tks for your advice

 

[Mazza]

Beautiful work. What a wonderfully generous wedding gift!

 

[Moondog55]

Got any TG45-06 tweeters left or know where to get them? I want another couple

 

[swin1]

fjadouce100: You'd be happy with either driver and really comes down to room size/box style preference. I used the 830875 for a bookshelf/stand speaker (~15L internal volume) and the 830883 for a small floorstander (~20L internal volume). The latter might play a bit better in a larger room but could be subjective. Other factor to consider might be use of a phase plug in the 830883 and the various pros/cons of that and what tweeter you're trying to match it with. What tweeter are you looking at and box style?

Mazza: Thanks Mazza but wouldn't recommend as a present. It was a originally a nice idea but took forever to get them finished, let's just say a few years after the day. It's socially preferable to have a present ready to give on the day rather than promising something for later, no matter how special it is. I always learn the hard way on this!

 

[fjadouce100]

My room is 15x13 ft. I see that the 830883 come already with a phase plug.
I do not have any idea what tweeter that can be best associated with either of the 2 midbass. Surely it shall be a budget one . Can I have input from other members as regards sound quality and most easily crossable?

 

[swin1]

fjadouce100: Probably the Vifa DX25 would be a good bet for a cheap tweeter. Link below. For that size room would lean towards the 830875. That combo will give you a great speaker. If you're not up to designing the crossover yourself the Madisound LEAP service will do the job.

Vifa DX25TG59-04 1" Fabric Dome Tweeter

 

[fjadouce100]

the Madisound service is no longer available but there is wealth of past crossover designs available for diyers. I have been fiddling this past month with vituixcad and shall try a xover p830875 and xt25.

 

[fjadouce100]

the Madisound service is no longer available but there is wealth of past crossover designs available for diyers. I have been fiddling this past month with vituixcad and shall try a xover p830875 and xt25.

Here a first trial. I invite any improvement.
tks

 

[Dave Bullet]

That's some bass shelf there....over cooked the BSC?

No. The xo looks good to me and about 3-4dB. The reason for the 100Hz hump / peak in the XO simulation is it is likely an assumed infinite baffle measurement. The Peerless sheet only shows about 85dB output at 100Hz. This speaker should target about 84dB with 3 - 4 dB BSC.

 

[Dave Bullet]

Here a first trial. I invite any improvement.
tks

You don't seem to have any BSC. Are you going to position these up against a wall? IF not - they will lack bass.

You should be targeting ~ 84 - 85dB overall system sensitivity.

 

[fjadouce100]

Dave, may I have your suggestions regarding components values for bsc. I lack experience in the bsc field .To reach the above design I have analysed dozens of known xovers and prceeded by trial and error. I have used simulated infinite baffle Frd and zma using vituixcad Splgraph

 

[samuelj]

Swin1,

Did you notice any audible increase in distortion around 600 - 2k for the 830875 as compared to 830883 ?
The 830883 has extra copper cap and phase plug that decreases the Le, hence lower measured distortions. Not sure how much is audible.

The 830883 in a 20l cab should give significantly more low frequency output compared to the 830875 in a 14l cab, vented. Wish peerless just put an extra copper can on the 830875, other things unchanged.